MEDICAL  ELECTRICITY 
RONTGEN  RAYS 
AND  RADIUM 

WITH    A    PRACTICAL    CHAPTER    ON    PHOTOTHERAPY 


BY 

SINCLAIR  TOUSEY,  A.  M.,  M.  D. 

CONSULTING    SURGKON    TO   ST.    BARTHOLOMEW'S    CLINIC.    NI-.W    YORK.   CITY 


THIRD    EDITION,     THOROUGHLY 
REVISED  AND  GREATLY  ENLARGED 


CONTAINING  X fi  1  PRACTICAL 
ILLUSTRATIONS,    16    IN    COLORS 


W.   B.   SAUNDERS   COMPANY 

1921 


DEDICATED 
TO  MY  FATHER, 

JOHN    EUART   TOUSEY. 


PREFACE  TO  THE  THIRD   EDITION 


MOST  important  advances  have  been  made  in  dental  and  gastro- 
intestinal radiography  and  in  the  standardization  of  apparatus  and 
technic.  The  latter  has  made  possible  tables  showing  the  correct 
exposure  for  radiographs  of  every  portion  of  both  sexes  and  of  every 
weight  and  measurement.  The  saving  in  time  and  the  certainty  of 
good  results  have  been  obtained  by  many  hundred  hours'  work  in 
studying  the  methods  and  results  in  thousands  of  radiographs.  The 
rehabilitation  of  those  suffering  from  the  results  of  war  injuries  is 
.•mother  important  subject. 

Then1  are  described  in  this  book  inventions,  patented  and  unpat- 
ented,  and  it  is  not  to  be  assumed  because  patents  are  not  specifically 
mentioned  in  connection  with  the  various  descriptions  that  there  are 
no  patents  or  that  the  rights  are  not  protected. 

SINCLAIR  TorsKY. 

\F.\S  YOKK  CITY,  .1 /</'</,  1921. 

9 


PREFACE 


Now  that  the  work  approaches  completion  the  author  realizes  that 
it  is  impossible  for  any  book  on  electricity  to  be  up  to  date.  A  weeklv 
magazine  would  be  more  apt  to  justify  this  title  in  the  case  of  a  science 
which  is  developing  so  rapidly  and  along  such  important  lines.  A 
systematic  attempt  to  present  what  has  been  done  and  of  how  to  do  it 
may.  however,  prove  useful.  Where  a  statement  is  ascribed  to  some 
particular  observer,  this  is  done  either  because  the  statement  has  not  yet 
been  verified  by  universal  experience  or  in  order  to  give;  due  credit  to 
the  discoverer  of  an  established  fact.  The  radiographs  in  this  book 
were  made  by  the  author  except  where  otherwise  stated,  and  the  tech- 
nic  employed  is  one  available  for  the  average  practitioner  who  desires 
uniformly  successful  results.  Lightning  speed  is  attainable  by  the  dis- 
tinguished expert,  but  sometimes  at  a  ruinous  expense  for  j-ray  tubes. 
The  author's  frequent  use  of  the  name  "  .r-ray  "  is  perhaps  excusable  on 
the  ground  that  it  is  the  name  Rontgen  gave  to  the  form  of  radiation 
which  he  discovered.  The  author  acknowledges,  with  thanks,  his  in- 
debtedness to  Dr.  Smith  Mly  Jelliffe  and  Dr.  Harry  F.  Waite  for  their 
assistance;  and  to  his  assistants  at  St.  Bartholomew's  Clinic  and  to 
other  gentlemen  to  whom  due  credit  is  given  for  radiographs  made  by 
them.  The  authors  consulted  are  mentioned  at  the  respective  parts  of 
the  book,  but  special  mention  should  be  made  here  of  the  works  of 
Houston,  ,J.J.  Thomson,  Curie,  Albert-Weil,  and  Bordier,  The  author's 
greatest  obligation  is,  of  course,  to  the  professional  friends  who  have 
n-fenvd  patients  to  him. 

SINCLAIR    TOIASKY. 


CONTENTS 


PAGE 

(IE.NEKAL  CONSIDERATIONS  ......  17 

STATIC  ELECTRICITY  ................  •_>.", 

Insulators  and  Conductors  .....  L'.~i 

The  Leyden  Jar  ...............  '_'»'> 

Nature  of  Electric  Sparks  ............  L'7 

The  Modern  Static  or  Influence  Machines.  .  :',() 

Sonic  Practical  Electric  I'nits  ........  Is 

Sources  of  Hiffli  Electromotive  Eorce  or  Static  Elect  ricitv    .  .  .  ">-l 

The  Physical  Effects  of  Static    Electricity.  .  ">."> 

Met  hods  of  Therapeut  ic  Application  of  Static  Klectricitv       .  "/) 

The  Dosage  of  Static  Electricity  .....  70 

Physiologic  and  Therapeutic  Effects  of  Static  Electricity  ............  71 

DYNAMIC  EI.KCTIUCITY  ..........................                 ...............  7S 

Nature  of  Dynamic  Electricity  .............                                   ........  7s 

Sources  of  Dynamic  Elect  rcity  ..............                            .........  N2 

The  Voltaic  or  C,alv;"i,c  Cell  ........................                  .  .  S'J 

Thermo-electricity  ......................  (.i7 

Storage  Batteries  or  Accumulators.  '.•!> 

The  Production  of  Electricity  l>y  Electromagnetic  Induction  Idti 

The  Dynamo  ..........................  ll'.'l 

The  Induction  of  Dynamic  Electricity  by  Electric  ('mi'eni<.  1^>'_' 

The  Character  of  the  Alternating  Elect  ric-hirht  ('uri'ent  liil 

Detection  and  Measurement  of  Electric  ('urrent<    .....  Itil) 

Elect  roma^netic  (  lalvanometers  .  .  17.'1 

The-  Measurement  of  Electromotive  |-'orce  I'.tl 

Regulation  of  Electric  (  urrents  ......  '_'u| 

Measui'ements  of  Resistance  ................... 

Electrolysis  ...................................  '-Ms 

The  Thermal  Effect  of  the  Electric  Current  'Jii'J 

L'HS 
Us  12 

l*Sli 

PHYSIOLOGIC   EFKF.("I\S  OK   I'j.K.c'nucrrv  ............  '-".>- 

Physiolouic  Effects  of  Electricity  upon  Microorganisms  'J!»'_' 

Physiologic  EtVects  upon  \'ertelirate  Animal-  '_'M.i 
The  Effect  of  Elect  ricity  upon  Anim:d  Tissu 


Muscular  (  'out  ract  ion  Result  inii  from  l'!lect  ric  Stimulation 
The  Myoiiraph  ........................... 

The  Elect  rocardiofifaph  ..................... 

Reactions  to  Electric  Stimulation  in  NYuromiisciilar  Preparation 
(  '(  >rt  ical  St  imula  I  ion     ........ 

St  imulalioii  of  t  he  <  V  rebel  la  r  Peduncle<  . 
Electric  Stimulation  of  the  Spinal  *  'ol'd 
Rellex  Stimulation  bv  Elecii'icitv    . 


KI.KC  i 'in  ii)i:s    .  .  . 

Materials  for   Electrodes 

Elect  rode.-  for  Sui  face   Applicat  ion 
Elect  rode-  for  <  ialvaiiopimet  lire 


11  CO  NT  K  NTS 

PACE 

Ki.K.tTKoDi  \<;NOSIS 38t» 

Progno-i<  Ba-ed  on  Klect  rodiagnosis  .  ...                                                     .  ...  397 

IONIC   M  K.DIC  \rioN    in    KI.KCTKOI.YSIS.  .                                                         399 

K\A.M1'I.KS  OK  CiAI.VANlC,    KAKADIC.    A  N  IP   Si  N  I  'Mil  1)  \  I.    Kl.lX    I  KoTH  K  If  \  I' Y 422 

1 1  vdro-electric  Baths ...  43(1 

O/one 44X 

Pm>l<    \I.   111. i  O.NSTHl  i  TIOV   AlTKK  \\  AH    IN.ITHIKS     .                                                                .  .  4A1 

I'm --1<  il. i  H, 1C    AND     III  KKAI'IH  Tir     KlTKtTS    ol      Kl.KCTKOM  A(iNKTS                         4A3 

Ki.KrnuriTY   IN    DI>I:\>F.S  OK  TIIK   Ni-:uvor>  SYSTKM 4AA 

Diagnosis  of  Disorders  of  the  Peripheral  Nervous  System.  .                  ....  4AA 

Disease  of  the  Peripheral  Sensory  Nerves 470 

Diagnosis  and   Treatment    of   Disease.-  of   Peripheral    Motor   Nerves 

and  Motor  Centers .  .  470 

Klect  roinechaiiot  herapy 4X3 

Practical  Kxamples  of  the  I'se  of  Condensers  in  Electrotherapeutics.     .  .  49A 

In  Connection  uith  the  Static  Klectric  Machine 49A 

In  Connection  with  Induction-coils A01 

Neuralgia  and  Neuritis A01 

Kli'd  i  icily   in   Treatment    of  Organic    Diseases  of  the  Central    Nervous 

System All 

Spinal  ( 'ord Al  1 

Brain Alti 

(ieneral  Nervous  Disorders AH) 

Neurasthenia A22 

Klectric  Sleep  and  Klectric  Death                                           A2X 

Physiologic  Causes  of  Death  liy  Klectricity A34 

I  Inai-KKi-x^rKNcv  CTHKKNTS A3X 

The  (  Midin  Pu-onator .  A4X 

Tesl:t  High-frequency  Current .  .  AAO 

Methods  <>f  Applying  High-frequency  Currents .  AA2 

\acuum  Klect  rodes  \\ith  Insulated  Stems AAS 

*  M  her   Applications   \\ith    Kt'tects    Hesemhling  Tho-e  of    High-frequency 

The  Physiologic  Kl't'ects  of  High-frequency  Currents  A(iX 

The  I'iH'ect- oi  ( ieneral  Applications  of  High-l reqiiency  ( 'urrents  A74 

Dial  hi-rm\  or  Theinioj  tenet  rat  ii  in (131 

I'HKNoMKNV      ACCOMI'ANYINC      '1111.      Tl{  A  NSM  I»IO.N     oK     Kl  ,K(  'TUK  'I  1  1      TllKotiiH 

(i  \sr.s        (142 

Imiixatioii  of  ( iases (142 

The  Pa --a  ne  of  KlectriciU  Through  a  Vacuum  M~> 

I'HO  10  i  ni.it  \i"i .  tlAA 

Principles  of  Phi  plot  herapy                                                                                    .     .  (17(1 

l-Aample-  of  the  Therapeutic  I  ••<•  of  Klecinc  Arc  Light  lixs 

'i  HI-.  /  - 1;  \  i  (W2 

Piopi-i  i  ies  of  t  he  ./-Hay  (1(14 

I  he  I 'rod i irt  ion  of  t  he  .c-Ka\    in  a  ( las-filled  Tube,  tl()(l 

I   i  in  i  is  of   I  .led  I  lc  (  ieliel  al  ols    Adapted    to    K\cit  Ilig   all    .1  -IJaV    Til  lie  7  1  A 

IJeuulat  ion  of  i  he  PrimaiA   ('urrent  72(1 

'I  he  Type  of  Tlllie     .....'...  7AX 

iial\    l,'a\-  7(U 

I'd--    \uf  hoi 's  '(  '..niacl    I  )iaphrat:m                                                                       .  XO  I 

Tin     Si-n-ll|\-eness  of  the   l-'illll.    Plate,  0]     P:ipel  XOX 

I :  • . :  x2(  i 

1 .01  ah/atloli   of    l-'oreign    Bodies.  XI H 

DP  \  i-|i  ipmeiit  i  if  r-l{a\    Pict  ii res  X70 

I  lii                       nd   Padiouraph\   of  Special   Part-  «\  the  Bmlv  X(lA 

Th.    Hi     H  (102 

T.-chnic  I'm   I  )ental  Padiom-a]»hy  OMO 

'I  h,-    \i  ck  «)XX 


CONTKNTS 

THK  .r-llAv:   Fluroseopy  ;i.iid    Radiography  of  Special    Parts  of   the   Body 

The  Chest  ...  '.I'.Ki 
.r-Ray  Diagnosis  of  Karly  I'liltnoiiary  Tuberculosis                           .      Hill 

Radiography  of  I  lie  Thorax  in  Pneumonia  Hll  I 

Bronchieclasis  „ H)|.~> 

Foreign  Bodies  in  tin-  Ijing.  Hll.'i 

The  Lung  Reflex    .  lOir, 

Radioscopy  of  the  Ksophagus.  Htltl 

Radiography  of  tin-  Spine 10ir> 

The  Abdomen  and  Pelvis  1(117 

The  Stomach  and  Intestines  1021 

The  Author's  Technie  for  (last  ro-mtest  inal  Radiography.     .  10^."> 

rrinary  Calculi 104S 

Hydronephrosis 10(>2 

E'yelography KM).". 

Perinephritis Hlli.'J 

Hemorrhagic  Nephritis    Hit):! 

Renal  Tuberculosis  1(1(11 

Radiography  of  Yosical  Calculus.  1(101 

Prostatie  Calculi HHif) 

Foreign  Bodies  in  the  Pelvic  Organs.  HMK1 

The  Pelvic  Bones 1(1(1(1 

The  Hip-joint ions 

The  Thigh 1071 

Radioscopy  of  the  Knee 1072 

Radiography  of  Bo\v-legs .    H)7."» 

Radioscopy  of  the  Leg K>7"i 

Fluoroscopy  and  Radiography  of  the  Foot    .  loso 

The  t'pper  Extremity Hixii 

Radioscopy  in  Diseases  of  the  Bones  and  .Joints 110.1 

Radiography  in  Tumors  of  the  Bones  and  Joints  1  10.") 

Acromegaly 1  Hiti 

Bony  Changes  Shown  by  Radiographs  of  Castrated  Animals  1107 

Osteomyelitis  and  Necrosis .    1107 

Acute  or  Chronic  Periostitis 110X 

A  Cast-  of  Obscure  Disease  of  the  Shoulder.  .  1  10X 

Syphilis  of  the  Bones.  1 1  HI 

Syphilitic  Inflammation  of  the  Bones  fNon-gimunalous  111:1 

Bone  Syphilis  in  Animals    .  1111 

Rickets 

The  Joints  in  Rheumatism  111") 

The  Joints  in  ( lout .111(1 

The  Joints  in  Rheumatoid  Arthritis  or  Rheumatic  (lout  .  1117 

Hypertrophic  Arthritis  or  Ost co-arthritis  1117 

Charcot's  Joint  —The  Tabetic  Joint  .  .  11 IX 
(lonorrheal  Arthritis.     . 
Tuberculosis  of  Bones  and  Joints. 
Kxamples  of  the  Value  of  1  he  .r-Ray  in  the 
Anatomic  Age  Determined  by  Radiology. 

Detection  of  Pearls  in  Oysters '.  .  .  11-0 

Physiologic  Effects  of  the  .r-Rays 1  i:',0 

From  Mild  Applications 

.r-Ray  Burns  or  Rontgen  Dermatitis.  .  .  1112 

Precautions  Against  .r-Hay  Injuries.  ...  111.) 

Ri  >vn  ,i:\i  >TM  MtAi'Y 

The  Treatment  of  Disease  by  the  .r-Ray 

The  Technic  of  Rontgen  Therapy 

The  .r-Ray  in  the  Treatment  of  Malignant   Di.-easc 
.r-Ray  Treatment  in  Particular  Diseases 

Skin  Diseases ... 

.r-Ray  Therapy  in  Tuberculosis    . 

Arthritis  Deformans    .  .  . 

Trachoma 

Radiotherapy  in  Syriimomvelia 

Old  Sprains.' '. .' .  .  .1101 


II)  ('ONTKNTS 

PAGE 

RoNTdKMiTHKKAPv:    .c-Ray    Treat  men  I  in  Particular  Diseases — 

Diseased  Tonsils 1192 

Locomotor  Ataxia  1  P>2 

.r-Ray  Treatment  of  Facial  Neuralgia  1192 
./•-Ray  Applications  Alter  Nerve  Resection  for  Tic  Douloureux        ,    119:3 

Prostatic  Hypertrophy    .  1  191 

./•-Ray  Treatment  of  ( loiter 1  P. Mi 

Pernicious  Anemia  .  .  1  19(1 

Hodgkin's  Disease  and  Pseudoleukemia  and  L\  mphosarcoina  1  PtS 

I'olycyt  hernia 1199 

./•-Hay  Treatment  of  Leukemia       .  1200 

Kpithelioma  1200 

Radio!  herapy  with  the  Tube  in  Direct  ( 'on tact  wit  h  t  he  Body  1217 

Technic  of  Direct  Applications 121S 

( 'arcinoma    .  ....    1220 

( 'arcinoma  of  the  Breast  ....  1222 

Recurrent  ('arcinoma  of  the  Larynx  1227 

( 'anccr  of  the  Tongue 1229 

( 'ancer  of  the  Shoulder 1229 

Secondary  ('arcinoma  of  the  Mediastinum 1229 

(  'arcinoma  of  Stomach  and  Intestines 1220 

(  'arcinoma  of  the  I"  ten  is 12.'30 

Sarcoma  . 12:31 

Treatment  of  an  Inoperable  Primary  or  Recurrent  Sarcoma  . 

Melanosarcoma 

Multiple  Pigmented  Sarcoma 

Fluorescent  Medicines  in  Connection  with  ./'-Ray  Therapy.  .  12:3") 
Nature  of  the  Radiance  from  Fluorescent  Substances  .  12:3(1 
Influence  of  the  Injection  of  Photodynamic  Substances  into  the 

Tissues  before  .r-Hay  Kxposures 12:3S 

Radiotherapy  in  Infectious  Diseases .    12oX 

Specific  Immunity .     12oX 

I! (Int gen  Applications  for  Producing  Sterility 12oX 

R  \mr\t .  .    12:39 

Radio-activity 12:39 

Origin  and  Cost  of  Radium 12  IS 

Variations  in  the  Radio-activity  of  Radium 1219 

Chemic  KfTects  of  Radium  Rays.  .  12.").") 

Radiographic  Kffects  of  Hadium  Hays 12f>(i 

The  Theorv  of  Radio-activity 12">7 

Physiologic  KfTects  ,,f  Hadium.  .  '.     .  1LT.7 

FtTects  on  Microorganisms 12">x 

Kffect  on  Plants 12(10 

KfTcct  on  Toxins 12(10 

Kffect  of  Radium  upon  Animal-  12(10 

KfTect  of  Radium  upon  the  Kve  12(11 
KfTcct  upon  Animals  During  the  Stage  of  Development  and  (  >n>\\  th.    12(12 

Pathologic  Kffects  of  Radium 12(12 

Thi  rapeutic  1'ses  of  Radium  .  12(>:> 

\pparatu<  for  Therapeutic  I  se  of  Radium  12(1:! 

The  Dosage  of  Radium   Radiation  12H."> 

Radium  Therapy  12(19 

Hadium  in  the  Treatment  of  Lupus  12(19 

Radium  in  t  he  Treat  men)  of  Skin   Diseases  12(19 

M  ilignanl    Disease  1271 

Ha  1 1  in  m  Puncture  for  ( 'arcinoma  1 27(1 
Therapeutic  ("sc  of  Normal  Saline  Solution  K \posrd  for  T\\  o  \Veek- 

to  ilie  Radiation  from  Radium  1277 

Radium  in  Kve  Di-ea-e-  1277 

Radium  in  I  'terine  I'ibroids  1  277 

Radium  in   N'er\-oii-  Diseases  127X 

Tonic  l.ttirt   Tpon  the  Heart  127X 

Substitutes  for  Radium  127X 

.    12X1 


MEDICAL  ELECTRICITY  AND  RONTGEN  RAYS 


GENERAL  CONSIDERATIONS 

MKDIOAL  electricity,  or  electro-therapeutics,  treats  of  the  applica- 
tion of  electricity  to  the  diagnosis  and  treatment  of  disease. 

Electricity  is  known  to  us  through  the  effects  produced  when  an 
electric  charge,  electromotive  force,  or  potential  is  developed,  just 
as  the  attraction  of  gravitation  is  known  to  us  through  the  effects  pro- 
duced when  a  body  is  raised  from  the  ground.  Hodies  in  which  an 
electromotive  force  or  potential  or  electric  charge  has  been  produced 
are  no  longer  in  a  state  of  repose,  but  tend  to  produce  a  variety  of 
effects,  one  of  the  simplest  and  most  direct  of  which  is  losing  their 
electricity  to  some  other  body  or  to  the  earth,  or.  in  other  words, 
becoming  discharged.  Many  other  effects  are  produced  by  the  electro- 
motive force  in  seeking  a  state  of  equilibrium — heat,  light,  the  .''-ray, 
mechanic  motion,  chemic  changes,  physiologic  effects.  Practically, 
every  one  of  the  effects  produced  by  electric  discharges  is  used  in 
electro  therapeutics;  and  some  recapitulation  of  our  knowledge  of 
electric  science  is  necessary  to  the  proper  presentation  of  the  special 
methods  of  producing  and  applying  electricity  in  medicine. 

ELECTRICITY 

Electricity  is  sometimes  regarded  as  a  substance  consisting  of  ex- 
ceedingly minute  negatively  charged  particles,  called  electrons,  which 
are  a  very  great  deal  smaller  than  atoms  in  which  they  normally  are 
in  a  state  of  equilibrium,  with  a  positive  charge  which  is  inseparable  from 
the  atom.  And  when  by  the  application  of  various  chemical  and 
physical  forces  the  state  of  equilibrium  of  the  electrons  is  disturbed 
there  are  various  manifestations  of  [lower,  such  a>  attraction,  repulsion, 
heal,  light,  electromagnetic  induction,  and  chemical  dissociation  or 
elect  rolysis. 

The  electron-  are  the  same  regardless  of  the  nature  of  tin1  atom- 
in  which  they  are  found.  The  underlying  fact  in  the  case  of  a  cur- 
rent of  electricity  i>  a  flow  of  electron--  from  the  negative  pole  of  the 
battery  or  oilier  generator  through  the  external  circuit  to  the  positive 
pole.  If  thi<  tact  had  been  known  ui  the  I  >eginning  this  would  have 
been  called  the  direction  of  the  cuiretit  instead  of  the  reverse.  h  H 
an  untoriunale  misnomer,  but  doe-  not  make  much  practical 
exc<  |)t  in  considering  the  pa— age  of  electricity  through  a  vactmii 


1^  MKOICAL    KI.KCTHICirV    AM)    UOXT(;EX    KAYS 

like  ill-1  ("onlid^e  .r-r:iy  tube.  There  the  electrons  travel  from  the 
negative  terminal,  and  by  their  impact  upon  a  target  u'ive  rise  to  vibra- 
tion railed  the  .r-ruy.  and  also  heat  up  the  target,  frequently  to  in- 
camle-cence.  And  it  seems  ridiculous  to  call  the  contrary-  "the  direc- 
tion <  if  tin-  curn-nt ." 

Th>-  various  familiar  means  of  "generating  electricity"  are  means 
of  freeing  the  electron-  and  applying  force  to  them,  which  they,  in  turn, 
exert  in  1  heir  peculiar  manner. 

Accepting  the  time  honored  classification  of  positive  and  negative, 
the  electron-  are  negative  particles  of  electricity:  a  neirat ively  charged 
body  contain-  an  excess  of  fi-ee  electrons  and  a  positively  charged 
body  contains  le-s  than  its  normal  quota. 

"There  are  t\vo  kind-  of  electricity,  positive  and  negative.  Each 
ordinary  atom  contains  a  number  of  electrons  which  are  always  negative, 
and  enough  ]>o-it  ive  electricity  to  exactly  balance  the  negative  electricity 
of  the  electron-.  At  present  it  appears  that  the  positive  electricity 
never  leaves  the  atom,  while  the  electrons  allow  themselves  to  be  taken 
away  or  added  to  with  relative  case1."  ! 

An  electron  i-  about  rrriMVi the  volume  of  an  atom,  but  it  is  so 

much  denser  than  an  atom  that  its  weight  is  •._,, ,',,,,  that  of  a  hydrogen 
atom.  I'  i-  sup]>osed  to  be  -pheric  in  shape. 

A  charge  of  electricity  is  either  a  surplus  of  elect n  ms.  which  is  a  nega- 
tive  charge,  or  a  ileticit  of  electrons,  which  results  in  a  positive  charge. 

A  current  <>i  electricity  is  a  movement,  transfer,  or  passage  of  elec- 
tron- from  one  place  to  another,  either  free  or  in  negatively  or  positively 
chartrei  1  at<  'in-  <  >r  i<  ins. 

Electricity  manifests  itself  in  three  principal  forms,  covered  by  the 
name-  of  .-••••!•.  •  •''••'<•,  and  fnr/nlic  electricity.  Static  electricity  is 
• ;.  at  re-t ,  :  n  tending  to  a  sudden  discharge  and  resumption 
of  eiertric  equilibrium.  Voltaic  electricity  is  electricity  flowinir  or 
_  •••  Ho\\  in  a  current.  Earadic  electrii'ity  is  a  deri\"ed  form  of 
ci;rreni  electricity  ;n  \\hich  there  are  rapid  alternations  of  direction 
a-  applied  in  medicine,  almo-t  always  relatively  hiii'h  ten-ion. 
There  are  -everal  tiioi lificat ions  of  the-e  which  may  be  produced  by 
-ui?:ii  in-es,  and  ainoiiu-  them  are  I.eyden  jar  di-charnc-  and 

-fi'eijuency  current.  Then,  again,  the  secondary 
:•  '.  liiiht.  the  .r-ray,  and  other  radiations — and 
luable  application-  in  many  different  condi- 

i 't    •    •     tricity   ilo\vn    to   about    a    century   au'o   was   the 
Thales.   one  of   the   seven   wi.-e  men  of 
'  •  -'    to  i -ail  at  tent  i.  >n  to  the  fact    t  hat   a  piece  of  amber 
a! t raci   ;;^i.i   limlio.     This  wa.-  in  liOO  B.  c..  but  no 
'  •  •    'hed    to   the   fact  .      About    :>00   n.   <  .   Theo- 
ob-ervation    thai    lynthuricum      pi-obalil>"    our 
-anie    property.      This    i-    all    the    pn-iii-e-s 
ric    scieiicr   il<  ,wn    to   the   time   of    1  )r.    '  iillieil . 


1!) 

physician  to  Queen  Kh/.abeth,  in  1  (>()().  His  investigations  showed 
that  many  substances  possessed  this  properly,  and  tho-e  in  which  it 
could  readily  be  produced  he  termed  "electrics,"  from  the  ('.reek 
electron,  amber.  Among  "electrics"  art;  amber,  sealing-wax,  glass, 
the  diamond,  hard  rubber,  sulphur,  resin.  Any  of  these,  when  rubbed 
with  silk  or  fur,  become-  electrified,  and  exhibits  at  once;  t  IK;  pro  pert  ie> 
of  attracting  light  bodies  which  are  not  charged  with  electricity,  or 
which  are  charged  with  electricity  of  the  opposite  sign,  +  or  —  (posi- 
tive or  negative),  as  the  case;  may  be;  of  repelling  bodies  charged  with 
electricity  of  the  same  sign;  of  inducing  an  ele:ctric  e-harge;  in  neighbor- 
ing bodies  by  a  pn>cess  which  may  be  like-tied  to  an  attraction  of  the; 
opposite  electricity  in  the  other  body,  and  a  repulsion  of  the;  electricity 
of  the  same  sign;  and  of  giving  sparks  or  discharging  the  whole;  or  a 
part  of  its  electric  charge  to  other  bodies  brought  near  enough  to  it. 
These1  sparks  are  accompanied  by  sound  and  a  smell  of  o/one,  and 
sensation  and  perhaps  reflex  muscular  contraction  if  applied  to  the 
human  body.  A  fine  examples  of  the-  production  of  electricity  by 
friction  is  obtained  when  one  walks  over  a  woolen  carpet,  shuffling 
his  feet,  and  producing  a  spark  sufficient  to  light  the  gas  or  to  give 
quite  a  smart  sensation  if  applied  to  a  person. 

"  Anelectl'ics  "  is  the  name  give-n  by  ( iilbert  to  t  he;  metals  and  <  it  her 
substances  in  which  he-  was  unable;  to  excite  an  electric  charge  by 
friction.  We  know  now  t  hat  the  reason  was  t  hat  these  bodies  are-  good 
conductors  of  electricity,  and  that  the  charge  was  carried  away  as 
soon  as  it  was  produced.  A  me-tal  or  any  other  good  conductor  may 
be  charged  with  electricity  by  friction,  provided  it  is  insulated. 

But  all  substances  are1  not  equally  charged,  and  they  are'  not  all 
charged  with  electricity  of  the  same  sign  or  polarity.  Those  which 
would  be  covered  by  Gilbert's  name',  "electrics."'  dove-lop  the  greatest 
amount  of  electricity  when  rubbe-d.  and  among  them  the  modern 
hard  rubber  is  perhaps  the  most  active. 

From  the  start,  it.  was  ne>ted  that  glass  rubbed  with  silk,  and  resin 
rubbed  with  cat's  fur,  became-  differently  charged  and  attracted  each 
other,  while  two  electrified  pieces  of  gla--  repelled  each  other,  as  did 
two  electrified  pieces  of  resin.  To  these  two  different  form-  ot  elec- 
tricity the1  te-rms  vitreous  and  rcxinoitx  were!  applied.  l.ate-r.  when 
it  was  found  that  they  we're-  complementary,  and  that  two  equal 
e-harge-s  neutralized  each  other,  the-  vitreous  ele-ctricity  was  called 
positive,  and  given  the  sign  plus,  while  the-  resinous  electricity  was 
called  negative,  and  given  the  sign  minus  There  i<  no  special  reason 
why  either  one  should  be  called  positive.  The  mimes  might  jusl  as 
well  have-  been  reversed.  \\hen  two  dissimilar  bodies  are  rubbed 
together,  one-  becomes  charged  with  positive  and  the  oilier  with  nega- 
tive-elect  rich  v  On  the  two-fluid  theory,  friction  separated  the  posi- 
tive and  negative  fluids,  and  an  excess  of  one  fluid  remained  in  one 
body,  while  an  excess  of  the1  other  was  formed  in  the  other  body.  {  hi 
the;  one-fluid  the'ory  an  excess  of  eh'ct 
which  becomes  positively  charged,  am 
body  which  becomes  negatively  chargei 
Ironic  theorv  of  electricity  will  be  pro- 
transmission  of  electricity  through  ga- 

!, 


20 


MKIHt  At.    KI.Kl  TKHITY    AXO    R(")N'T<iK\     KAYS 


in  the  li-t  hoc< imcs  po-iti vely  charged,  and  the  one  later  in  the  list  be- 
come- negatively  charged  :  Fur.  wool ;  ivory,  glass;  cotton,  silk :  the  hand. 
\vood;  -ealinu'-wax,  shellac:  resin,  metal-:  sulphur.  India-rubber:  gutta- 
percha.  celluloii  I. 

The  attraction  of  an  elect  rifled  body  for  other  bodies  is  illustrated 
by  tin-  motion  of  a  pith-ball  suspended  near  an  electrified  body,  such 
as  '  lu>  prime  conductor  of  a  static  machine.  The  pit h -ball  immediately 
swings  over  in  contact  with  the  prime  conductor,  and  as  soon  as  it 
touches  it  i>  auiain  repelled.  According  to  our  diagram  (Fig.  I),  the 
positive  electricity  in  the  prime  conductor  attracts  the  negative  elec- 
tricity  in  the  pith-ball  and  repel-  its  positive  electricity.  \Yhen  The 
piti.-ba'.l  come-  in  contact  with  the  prime  conductor,  it-  negative 
charge  enter-  into  the  prime  conductor  and  neutralizes  a  portion  of 
1  he  positive  charge  therein.  The  pith-ball,  being  then  entirely  charged 


it       po>itive    electricity,    is    repelled    by    the    prime    conductor.      In 

Fi<r.    -   the   [lith-ball    i-   represented   as   being  suspended   between   the 

prime    c  -     '"..rued     with     electricity.      It     then     swings 

.-    '  >  r  lately  to  one  ;.     :  •  :  c  other,  becoming  charge'  I  at  t  he  first  contact 

with    i"  -hive   elect ri    it     .    and   then    being  attracted   by   the   negative 

pi    i.    where    it    loses    its    positive    charge,    and.    acquiring    a    negative 

repelled    bv    the  negative   pole  ami   attracted    by   t  lie 

;        ;ive.      'I     '•  -;  :  te  rep  tlsimi   of  two  similarly  chai'ged  bodies  forms 

t  he  '  i'  1  he  iti-1  r'lliient    callei !  1  he  elect  n  isci  ipe. 

The  electroscope  Fin.  •>  consists  of  a  glass  case  in  which  a  bra--  rod 
terminate-  below  m  two  pieces  of  »old-!caf.  and  above  in  a  brass  knob. 
Un  britiii'iiig  the  brass  knob  near  a  positively  charged  body,  negative 


i-    a<  t  r.n-i  <  i  i         po-itive    charge    being    re- 

Ipoii    become   \ 
11          •  i-   neiuhbi  irh<  • 

•::<-t  her.  I  .lit    if  the  <_da-- 

,    '       .     in    :  •  •      pririn     cotiducli  it1,    c  >r    had    recei\  ei  i    a 

iiild    liave   1  ieci  niie    pi  .-'i!  i\ .  -\y 

•    }  •;  \  <     remained    divi  -r^,  sit 

•   :i  :  u-  i-eli    lo-l     1  vil  h    -ollie    coin  lllcl  iii-    -lib- 


21 


In  \YulCfs  electroscope1  the  u'old-leave-  are  replaced  by  two  quint/ 
filaments  coated  with  platinum.  The  filaments  are  fa-tened  t(>  ,-i 
conducting  rod  at  the  top.  and  are  al.-o  joined  together  at  the  bottom, 
where  there  is  a  light  weight,  pi  oducing  a  uniform  tension.  An 
electric  charge  causes  the  filaments  to  div< Tge  most  widely  at  their 
middle  (joints  (Fig.  \  > .  The  amount  of  thi-  divergence  i-  observed 
by  a  microscope  magnifying  70  time.-.  The  objective  of  thi-  micro- 
scope is  of  low,  and  the  eye-piece  of  hiidi.  power.  In  this  wav  the 
objective  may  be  at  a  convenient  distance  from  the  filament-. 

Another  example  of  the  repulsion  between  bodies  charged  with  the 
same  polarity  is  seen  when  one's  hair  --land-  on  end  under  treatment 
by  static  electricity.  The  discharge  of  static  electricity  produce-  ;i 


s]>ark.  with  a  development   of  noise.  li»'ht.  heat,  and  chemical  effect-. 
[Muscular  contraction  and  sensation  may  al-o  be  produced. 

An  early  type  of  static  electric  machine  con-i-led  of  a  cylinder 
of  glass,  which,  as  it  revolved,  was  rubbed  by  fur  or  silk,  and  thu- 
became  charged  with  electricity.  At  another  part  of  it-  revolution 
this  electric  charge1  was  carried  off  by  metallic  comb-,  which  were  -o 
near  that  the  electricity  could  lea])  aero--  to  them  from  the  glass. 
The  combs  were  connected  with  a,  metallic  ball,  both  being  insulated. 
and  the  rubbers  were  connected  with  another  metallic  ball.  The-e 
two  formed  the  poles  or  prime  conductor-  of  the  machine.  The  whole 


would  produce  a  very  small  amount   of  electricity,  but  enouirh  to  pro- 
duce the  characteristic  effect-  of  -tatic  electricity. 

A   bodv   charged    with   -tatic   electricity   may   produce   a    charge   in 
another  body,    iir-t.    by   conduction   or  convection:   second,   by  a    -park 
discharged:    third,    by    induction.      The   charm'   produced    in   tin     p    ' 
conductor-    of    the    old    static    machine-    illustrates    one    and 
combs  becoming  ''haruvd  bv  a  spark  discharged  trom  the  Li!a 
prme  conductors  receiving  their  charge  by 
Figs.  .")  and  l>  show  what    take-  place  when  a   body  i-  cl 
conduction    or    -park    from    a    body    already    charged. 
'Tli.  \\  uliT.  I'hv.-ik,  7.   ii  .    Vpri    I.'..  l'.«iT 


'__'  MKDICAL    KI.K<  TKH   ITY     AND    KONTGKN     KAYS 

positive  pole  of  a  -tatic  machine,  and  l>.  an  in-ulated  metallic  object. 
The  proc-'--  i-  twofold.  There  is  an  attraction  oi  the  negative  elec- 
tricity in  t>  to  n,  and  a  pa.--aue  of  a  part  of  the  positive  electricity  in  fi 
into  t>.  The  re-ult  i-  that  /*  lieconi"s  charued  with  po.-itive  electricity 
and  remain-  so  after  removal  from  the  neighborhood  of  a.  The  positive 
charge  on  <i  i-  partially  neut  rali/ed,  but  if  a  is  the  positive  pole  of  a 
static  machine,  thi-  deficiency  i-.  immediately  supplied. 


•    r,       I,-,       i-.-  Fi 

\          •  icti  •: 

i-    . :        -  .  •         •  .          it    wit  a  a  ci  inductor. 

•  •   •     •  '       -  i  ir :  i    i  -    a  t  - 
tract rd  .    ~;iini'  .-itrn 


A  charge  i>y  induction  is  shown  liy  the  ex])erimenl  of  hrinu'lnu  an 
in-iilated  liody  /'  in  tlie  diagram  < '  Ki<i.  7  near  the  prime  conductor  a, 
which  in  tin-  case  is  supposed  to  lie  positively  charu'ed.  The  negative 
electricity  in  //  i-  attracted  to  the  sui'faee  nearest  a.  while  the  po-itive 
electricity  in  h  i-  repelled  to  the  surface  farthest  away.  I'nder  these 


insulated    bodies    which     are    .~c|iarat 


condition-  the  farther  extremity  of  h  \vill  exhibit  the  characteristic 
effect-  uf  ;i  liodv  charged  \\ith  po.-it'u'e  electricity.  It  will  attract 
a  iH-iiaiively  charu'ed  piih-liall.  for  in-tance.  I>u1  if  it  is  now  removed 
from  the  neighborhood  of  «.  it-  electric  charge  would  a.ii'ain  become 
in  ulral.  ['.in  if  /<  were  loiu-hed  by  a  conductor,  c.  at  any  time  while 
under  the  intluence  of  the  po-iti\-e  charuc  in  a,  it-  positive  charge 


would  d     into    the    conductor,    and    an    additional    negative 

chaf.  '  ei|        I'M"-.     v       tVi  iln     t  he    ci  illdllcti  >r.       The     lat  ter 

:  '  .    and    if      How.    I  he    in.-ulated    bodv,    Ii.    \\hich    i- 

•     •  '  '  :ia1  ive   eled  ricit  y.    I  ie    ca  rri<  'd    to   a    i  li-t ance 

•  1 1  d   -upp<  irt      \-  \<JL.  (.i  .   it    will  I  ie  ioiind   to 

•    ei-i  ric  cha  riie. 


In  another  experiment  (Figs.  1(1  and  11)  two  bodie-.  d  and  <. 
closely  in  contact  with  each  other,  are  brought  near  a  po-itivelv  chariied 
body,  r;  their  entire  charge  of  negative  electricitv  i-'  attracted  into  d. 
which  is  nearest  c,  and  the  entire  positive  charge  would  be  carried 
into  r,  farthest  away.  If,  now.  the  two  bodies,  d  and  r,  are  separated, 
it  will  be  found  that  all  parts  of//  are  negatively  charged,  and  all  parts 
of  r  positively  charged,  and  that  these  charges  will  remain  permanent 
even  if  they  are  removed  to  a  distance  from  each  other,  and  from  tin- 
body  c.  from  which  the  charge  was  originally  induced. 

A  somewhat  similar  effect  is  produced  (Figs.  12  and  loj  if  //  is 
grounded  or  connected  with  the  earth  while  under  the  influence  of  //, 
and  this  ground  connection  is  broken  while  b  is  still  near  //.  In  this 


case  the  entire  positive  charge  of  /;  is  driven  to  the  earth,  and  b  be- 
comes completely  charged  with  negative  electricity.  This  charge 
remains  even  after  b  is  removed  from  tin-  neighborhood  of  a.  The 
same-  effect  is  produced  (Figs.  14  and  15  i  if  a  negatively  charged  body 
is  brought  in  contact  with  b  and  removed  from  it  while  b  is  still  under 
the  influence  of  a. 

All  modern  static  machines,  called  influence  nuichi>/< *.  depend  on 
these  principles. 

Two  bodies,  b  and  r,  separated  by  a  sufficient  air-space  or  by  sonic 
other  dielectric  ('Fig.  1(>\  may  be  influenced,  the  one  by  //,  positively 
charged,  and  the  other  by  d.  negatively  charged.  //  being  brought  in 
contact  with  b,  and  d  with  r,  b  becomes  completely  charged  with  posi- 


tive  electricity  by  conduction  from  <i,  and  c  with  negative1  electricity 
by  conduction  from  d.  Both  are  ii'iven  a  much  heavier  charge  than 
would  otherwise  be  the  case  in  consequence  of  the  attraction  of  the 
two  oppo.-ite  charges  of  electricity  for  each  other  exerted  acid--  the 
space  between  b  and  c.  A  greater  amount  of  electricity  enter-  trom 
the  positive  poli\  a,  in  consequence  of  this  attraction,  and  similarly 
in  the  case  of  r.  The  Leyden  jar  and  various  other  types  oi  conden-i  : 
depend  upon  t his  principle. 

An  electrified   body  may  part    with   its  charge,   fir-t.   in   tin 
lust  rat  t-d  by  Fig.  ~).  by  removal  from  the  neighborhood  oi  ' ; 
body;  second,  by  conduct  ion   through  conductors  to   tl 
oppositely  charged  body:  third,  by  convection*  foui 
ruptive   discharge.      One   and    two   have   already    been 


_t  MKDH  AI.    F.I.K*  TKHITY    AM)    Kn.NTOKN     HAYS 

cussed.  Tliri".1:  when  a  body  i>  clcci  rifled,  its  charge  has  a  tendency 
to  accumulate  wherever  ii  ha-  -harp  puints,  and  when  any  other  body  is 
1  <r(  i  u  i:  hi  sullicieiit  ly  close  a  -i  lei  it  <  li-charue  takes  ])lace  between  the  two. 
accompanied  by  a  faint  violet  linlil,  vi-ible  both  on  the  points  of  the 
electrified  body  and  on  the  .-urface  of  the  body  to  which  the  discharge 
passes.  Such  a  discharge  i-  known  a-  the  .--In  fie  hr«  z< .  or.  in  talking 
of  hii:h-fre(|iiency  currents,  as  i  he  < JJlun  .  It  can  be  seen  in  a  darkened 
room  whenever  an  elect  rifled  body,  like  one  pole  of  a  slat  ic  machine  or  a 
charged  wire,  presents  a  point  or  i.-  moderately  near,  but  not  within 
^parkiim  distance,  to  the  oilier  pole  or  some  other  body,  \\ith  ex- 
tremely hiizh  charu-e<  of  electricity  thi-  same  convective  dischar<i'(i  iV<  m 
point-  on  the  charged  body  can  be  seen  to  take  place,  even  if  no  other 
•  anywhere  near.  This  constitutes  the  phenomenon  called 
>'  /.''•</'  /  ..  sometimes  occurring  on  the  top  of  the  masts  of  ships. 


STATIC  ELECTRICITY 

INSULATORS   AND   CONDUCTORS 

TIIK  reason  why  a  metal  kill  upon  a  glass,  standard  retains  its 
charge  ot  electricity  is  because  gia»  is  an  insulator,  or  a.  non-conductor 
ot  electricity.  The  terms  cnn<lti<-lor  and  mrn-i-o-ndiictur  arc  relali\'e. 
t'onduetors,  perinit  the  passage  o|  electricity  readily,  i.  < ..  with  litilc 
resistance.  Xon-c'onductors  transmit  elect  ricity  very  poorly,  01 
with  great  resistance,  (ilass  and  air  are  very  p<  M  >r  conductors  of 
electricity,  and  an  electrified  body  will,  ii'  insulated  by  either  of  these 
two,  lose  its  charge  very  slowly  under  ordinary  conditions.  Air 
may  become  a  good  conductor  in  seyeral  dift'ei'ent  ways,  one  of  the 
most  interesting  being!')-  ionizjition  of  the  air  under  t  lie  influence  of 
the  ,r-ray.  1  he  discharge  of  an  electroscope  and  the  Calling  together 
of  its  leaves  under  ionixation  of  the  air  by  the  x-ray  have  been  pro- 
posed as  a  quantitative  measure  of  the  latter. 

Among  the  conductors  are  metals,  charcoal,  graphite,  acids,  water, 
and  the  human  body.  Among  partial  conductors  are  linen,  cotton. 
alcohol,  ether,  dry  wood,  and  paper.  Among  mm-conductors  are 
oils,  porcelain,  silk,  resin,  gutta-percha,  shellac,  hard  rubber,  paraliin. 
glass,  and  air. 

An  electric  charge  passes  through  a  conductor  easily  and  quietly, 
unless  the  conductor  forms  too  small  a  path  for  the  quantity  of 
electricity  passing  through  it.  In  such  a  case  the  conductor  becomes 
hot.  In  the  case  of  a  non-conductor,  practically  no  (low  i-  permitted 
unless  the  pressure  or  tension  is  yory  great,  and  then  the  electricity 
does  not  pass  by  conduction,  but  by  a  di>ruptive  discharge.  It  seems 
to  break  through  the  non-conduct  or.  ami  in  the  ca>e  of  violent  dis- 
charges of  electricity,  as  in  lightning,  the  effect  upon  non-conductors 
is  most  destructive.  Conductors  are  used  for  the  passage  of  electric 
charges  and  currents.  Non-conductors  or  insulators  are  used  to 
protect  the  charged  conductors  from  contact  with  other  conductors, 
and  thus  to  retain  their  electricity. 

Foi    all    practical    purposes   the   earth    may    be   regarded    as   an    in- 
exhaustible storehouse  of  boil:  positive  and  negative  electricity.      In 
a  static   machine  a  charge  communicated   to   both   poles   is   much   in- 
creased if  one  of  them  is  groiini  led  nv  connected  wit  h  the  earl  h.      \\  hen 
two  perfectly  insulated  dissimilar  bodies,  are  rubbed  together,  a  nega- 
tive charge  will  be  produced  in  one  and  a  positive  charge  in  the  other. 
bv  ;i,  process  which   may  be  regarded  as  a  disintegration  of  a  norn  al 
neutral    charge    in    both    into    positive    and    negative    charge-     all     the 
positive   electricity    of   both    beinu'   accumulated    in    one   body    and    all 
the  negat  ive  in  t  he  other.      If.  now,  one  of  these  bodies,  say  1 1  e 
live    one.    is    grounded,    an    additional    amount    nt   negative  elect] 
enters  it  from  1  he  cart  h.  att  racled  into  the  negat  ive  pole  by  1 
charge   in   the  other   pole,   and    then   with   a  stronger   nega'ive   : 
stronger  positive  charge  i-  produced  in  the  other  by  in 


•J(i  MKDIC.VL     KLKCTHU'lTY     AM)    K<)N(.TK.\    KAVrt 

is  assuming,  of  course,  thai   the  process  of  friction  is  going  on  while 

t  ills  gt''  'Ulid  ci  'lined  h  >ll   l>   made. 

It  appears  to  be  universally  true  that  the  development  of  the 
pnsit-ive  ci:arge  of  electricity  oi  any  lorm  whatsoever  is  attended 
e  development  of  an  equal  negative  charge.  An  electric  charge 
exerts  H  force  -its  dtclmnmti '•(  J'orct  —tending  to  produce  again  a 
neutral  -tate.  In  the  case  of  static  electricity,  the  charge  is  altoget  he:1 
on  the  .-nriace  of  tiie  electrified  body.  This  may  be  due  to  the  repul- 
simi  \vhicii  an  electric  charge  exerts  upon  electricity  of  the  same  sign, 
either  positive  or  negative,  and  tiie  tension  or  pressure  of  static  elec- 
tricity  is  so  great  that  this  repulsion  repels  practically  the  entire  charge 
to  tiie  surface. 

Static  electricity  nmst  be  considered  separately  from  dynamic 
electricitv  because  it  is  only  by  the  so-called  static  machine;  that 
such  verv  high  voltages  can  be  directly  and  readily  obtained.  The 
very  existence  of  a  useful  charge;  of  static  electricity  requires  that  the 
charged  body  shall  have  b<>th  capacity  and  insulation.  The  differ- 
•  •••  between  electricity  in  the  form  of  a  current  and  electricity  stored 
up  as  a  static  char  ire  is  comparable  to  the  difference  between  water 
p  ured  through  an  open  ring  and  water  poured  into  a  cup.  "  A  cupful 
>  :'  water"  implies  that  the  cup  is  closed  at  the  bottom,  and  "a  charge 
of  -tatic  electricity''  implies  that  the  charged  body  is  capable  of  retain- 
ing the  charge,  i'seful  charges  of  static  electricity  are  of  such  high 
lies  thai  the  requisite  degree  of  insulation  can  be  conveniently 
obtained  only  by  means  of  apparatus  dependent  upon  the  excitation 
of  non-conducting  plates  of  glass,  hard  rubber,  {taper,  or  mica. 

THE   LEYDEN    JAR 

A  class  jar.  coated  on  the  outside  and  on  the  inside  with  tin-foil 
'     ,ab  ''it    naif  its   height,   and  with  a  brass  rod   fastened  to  the  cork 
and   connected   with   the  inner  coat   by    means   of  a  loose   chain,  the 
-    i'"d    lerminating   above   in    a    knob,    constitutes   the   apparatus 
,    :    ••  l.eyden  jar.      To  charge  it,  the  knob  on  the  upper  end  of 
the  roil  is  brought  near  enough  to  one  pole  of  the  static-  machine  to 
receive  a  charire  by  conduction,   convection,  or  by  spark   tT'ig.    \~). 
.'  tl  e  -    me  time  t  he  outer  coat  of  tin- foil  is  grounded  by  holding 
'•  jar  in  the  hand.      The  inner  coat  becomes  fully  charged  with  p<>si- 
t  ive  electricity  if  it  i<  t  he  positive  pole  of  the  static  machine  which  is 
I  1    e  .  uter  coat,  separated  from  it   bv  onlv  the  eighth  of  an 
•  '  ness  "l  the  glass,  becomes  negativelv  charged  by  induction. 

I  ins   negalive  charge  of  the  outer  coat   is  attracted 
into  it    from  the   ground.      The   two    charges  are  a 
very  greal   deal  stronger  than  eit  her  would  be  alone, 
in    coii-eotience    of    the    attraction    of   the   two  for 
>•..     .    oilier,   and    the    consequent    condensation    of 
eledridtv.      Mich   a  charged    I.evden  jav  will  ret ain 
i' -  charge  for  a  long  time   in    spile  of  1  he   fact    thai 
r  is  e.-ti'ried  about  and  handled  by  the  outer  co^t  ing, 
1  i< -et  down  on  a  glas<  |ilate  or  sonu;  o1  lier  in- 
\  the  knob  c.  .nncct  e.  I  wit  h  1  he  inner  <•<  >a1  hig 
:  ny  d i-charge  occurring.      Touching  both  (I  e 
i  connect  e(i  \\  ith    t  he   inner  ci  >at  ing  at   1  he 


STATIC     ELECTRICITY  '27 

same  time  will  produce  a  discharge,  which,  in  the  case  of  a  Levden 
jur  dt  iiuy  size,  occurs  us  u  very  brilliant,  while,  largo  spur k. 

Such  u  discharge  produces  physiologic  effects,  the  ino.-t  manifest 
of  which,  with  a  .small  jar,  being  a  single  muscular  contraction  of  the 
forearm,  hut,  extending,  with  a  lar.^e  jar,  to  the  muscles  of  the  arm 
and  even  to  the  chest.  A  very  large  Levden  jar  gives  a  powerful 
shock,  and  so  does  a  haltery  of  Leyden  jars  with  their  outer  coatings 
all  connected  with  one  terminal  and  the  inner  coutings  with  another. 
The  violence  of  a  discharge  \viil  ilepend  upon  the  area  of  lead-foil 
in  the  Leyden  jar  or  jars,  and  the  tension  of  the  charge.  A  whole 
group  of  people  may  receive  a  shock  at  one  time  if  they  join  hands  in 
a  ring,  and  the  outer  coat  ol  a  large  Lev  den  jar  he  grasped  hv  one 
person,  and  the  person  at  the  other  end  touches  its  inner  rod. 
Experimentally,  a  whole  regiment  of  soldiers  have  heen  given  a 
simultaneous  shock  in  this  way. 

To  avoid  disagreeable  shocks,  Leyden  jars  should  never  be  left 
in  a  charged  condition,  hut  should  be  discharged  by  a  special  curved 
metal  rod  with  an  insulated  handle  made;  for  this  purpose. 

Leyden  jars  form  an  important  part  of  the  apparatus  for  treat- 
ment by  static  electricity  and  by  the  modern  high-frequency  currents. 

If  a  Leyden  jar  consists  of  a  glass  tumbler  with  a  loose  inner 
coating  in  cup  shape,  and  an  outer  one  of  the  same  nature  and  is  charged 
in  the  ordinary  way,  the  inner  metal  coating  may  be  taken  out  and 
handled,  and  will  be  found  not  to  possess  any  electric  charge.  The 
outer  coat  may  then  be  removed,  and  will  be  found  to  have  no  charge. 
The  entire  charge  remains  upon  the  two  surfaces  of  the  dielectric, 
the  glass,  and  on  reassembling  the  parts  of  this  dissected  Leyden  jar, 
it  may  be  discharged  in  the  ordinary  way. 

The  other  type  of  condenser,  consisting  of  some  dielectric  sheets 
of  mica  or  paper,  between  which  are  sheets  of  a  conductor,  like  tin- 
foil, are  used  where  a  very  large  surface  is  required,  and  where  1 1n- 
tension is  comparatively  small.  Such  condensers  will  be  described  in 
greater  detail  in  connection  with  induction  coils. 

NATURE   OF   ELECTRIC   SPARKS 

The  discharge  occurring  between  the  two  poles  of  a  static  machine 
varies    in    accordance    with    their   distance    apart,      ll    they    arc    very 
close  together,  there  is  an  electric  arc:  if  a  litlle  further  apart,  there  is 
an   almost   continuous   thread    of  white    light.      Separating    the    poles 
an   inch  or  two.  the  discharge  changes  to   a  thread,   or  a  number  oi 
threads,  of  violet  liu'ln.  with  hrilliant   white  sparks  at   each  pole.      I: 
a  bit  of  wood,  like  a  match,  is  held  close  to  1  he  positive  pole,  the  spark 
will  be  deflected  toward  the  wood,  hut   little  or  no  effect  is  produced 
hv  wood   held   near  the  negative  pole.      If  a  pointed    metal   elc 
connected   with  1  he  earth   is  held   anywhere  near  the  positive  pole,  a 
bright  violet  light,  like  u  star,  appears  upon  the  point,  ai  d  \\    ei    : 
brought  almost  in  contact   with  the  positive  pole,  a  bright   vhite  co 
t  intu  His  thread  discharge  i  akes  place.      \\ 'hen  t  he  same  i 
electrode  is  brought  near  the  negative  pole,  the  star  does  noi    ; 
unt  il  the  point  is  within  a  few  inches  ot  t  he  pole,  and  \v    en  n 
still  nearer,  a  violet  brush  discharge  takes  place  fro]  ; 

negative  pole,. 


he-  discharge-  occurring  bet  ween  t  he  two  poles  of  a  static  machine, 
l  he1     are  separated    bv  a  considerable;  distance,   is  best   see-n   in 
•    ciied  root  i  .      The  whole  space  bet  we -en  t  tie  1  wo  poles  is  filled  by 
•    •    a-.-  of   violet    light.       From   the   positive  pole;  there;  shoot 
iiicou-lv    pe-rhap.-    a    do/en    xigxai:   threads    of   violet    light, 
<  .  •:  ,.'.'  e;  r:  nee  likened  to  a  fox's  tail,  while;  the;  discharge;  from 
.-"•at : ••  «•  pi  ile  i-  -imply  a  diffused  eliluve  of  violet  lig'nt.      ( 'onne-ct- 
e  inner  coat   oi  one   I.eyden  jar  with  the  positive,  and  the;  inner 
•    er    I.evden   jar   with   the-  negative,   pole,  and  connecting 
oipe-r  coat-  i<  Aether  or  buih  in  t  he  e-arth,  the  discharge  between 
io[e-  MI    a   -'.••'   ''    machine-  ceases  to  be  a  continuous  one-,  and   be- 
>-  a   -Ucce--i  .n   of  briiliaiit    large  white;  sparks.      The-se  .-parks  are- 
e  -;:'    e  a-   '    e  <park  produce'd  bv  t'ne  discharge-  ol  a   I.eyden 
jar.      In    the-    diagram    (Fig.    1<\)  [>  is   the 
.r  positive    and    n    the    negative-    pole-    of    a 

static   machine.      As  the-    e-le-dric    charge 
i-     produced     by    the    operation    of    the 
mae-hine,  the-  inner    coat    of   the-    l.e-yde-n 
jar,  /.  is  positively  e-harge-d.  and  the-  nega- 
tive elee-trie-itv  in  the;  out  e-r  coat  s  of  bot  ii 
jars,  conm-cted  by  a    brass    rod.    is    at- 
tracted   to   the    outer  coat   of  /,  and  this 
strong  negative-   charge  of  it-  outer  coat 
-till  •      re  1    e  capacity  of  the  inner  coat  for  peisit ive  electricity. 
-..:  ,e  proce--    -..i.e-    place;   in  the-  I.eyden    jar.  /.  whose  inner  coat 
.•e- a    c        e..  .     iie-gat  ive  charge1,  and  whose  outer  coat  receives  the 
ge- of  both  jars.     \\he-ntheniaehineisturnedori.itis 
'    a'        en  irusli    or   -park   di-ediarge  does  not    take-   place 

•     i-    space-    he' we-ej]    the    pole-    of    the    machine.       The-    charge    is 
'    red  up  iti  the-  two   I.e-yde-n  jars,  and  in  eae-h  one-  is  bound  by 
"  I'a'-i  loti    (•  -..   •      N    between    the    positive   ami    ne-gative;   charge-s, 
a'ed  onl\    ;r     the:  1  !ijckne-ss  of  a  sheet  of  glass.       Fve-nt  uallv,  t  he- 
ir-ciin  c       -      harge-d  and  a  dise-harge  occur-.      A  brilliant 
.   pa--e-~  a  e-  -pace1  be-twe'e-n  the-  pole-  of  the-  machine. 

; -  xi'_rxaL!  line.      At  the  same  time  a  crown  of  zigxag. 
lies   -tarts   upward   from  the  uppe-r  e-dge-  of  the- 
jar.      The;    inner    coat-    have-    parted    with 
e    ••  i  ft  1  v    by    discharge    from    the-    mnm-r   coat    of 

''..'    '-I    the-    oppositf-Iv    e-hai'U'e-d    one.    through    the- 
:  t  lie:  machine-  and  the-  intervening  air-- pace,  and 
>    miter  to  the-   inner  coat   of  the  same  jar 
•  !  e  tila--.      The  latter,  in  each  jar.  is  a  consequence 
er   coat,    which   leave-   an  excess  of  charge 
•  oiind   bv  the  attract  iein   of  the-  internal 
1  ••.'•(•--  I  arge  of  the-  opposite-  sign   is   liberated 

'     e  i       .    '         i- j  uce  i  >f   both    I.cvden  jar-  and  part  of 
r      ,    <•   exe-liaiiged    and    neutrahxed    through 
Ti  e   rod.    although    large-  enough  1"  carry 
. '  '    of  elect  rich  y    in   a   quiet    cnrre-nt . 
ce  •  :  ,e  i  ij  icvat  i\-e.  de\'e-lo]  is  an  e-nor- 

e  '  '  i      pa      age-    '  <\     -lledi    a     d  i-chal'ge    as 

tin     oi    t  he-  d  ischarge   ca  n    be  .-e'en 
1  :  f  stirfae-e-  of  1  he  glass. 


STATIC     KLKCTKICITY  2.J 

The  resistance  of  the  hitter  path  is  great,  but  ;i  portion  of  a  discharge 
simply  cannot  gel  through  the  brass  lod,  and  has  to  leap  aero.-.-  ll,e 
space  described.  Leyden  jar  discharges  modified  by  inductive  im- 
pedence  in  coils  and  the  like  for  in  the  modern  high-frequency  appan.t  u-. 
If  t  he  poles  of  the  static  machine  are  loo  widely  separated,  no  discharge 
will  occur.  The  Leyden  jars  will  simply  hang  there  in  a  fullv  charged 
condition,  and  in  the  dark,  of  course,  a  convect  ive  discharge  can  lie 
se'Mi  leaking  into  the  an1  from  ail  point-  or  rough  place.-  in  the  poles 
or  jars.  When  the  poles  are  brought  nearer  together,  the  flashes  again 
take  place,  and  are  at  first  loud  and  brilliant,  and  at  long  intervals 
perhaps  only  fifteen  in  a  minute.  As  the  poles  are  "brought  nearer  and 
nearer,  the  flashes  become  less  brilliant  and  more  frequent,  and  at  a 
distance  of  half  an  inch  or  an  inch  they  form  a  continuous  stream  of 
white  light  with  a  very  rapid  succession  of  reports,  which  are  not  a- 
deafening  as  when  the  distance  was  greater.  If  a  static  machine  has 
beeii  running  with  the  poles  so  wide  apart  that  no  discharge  occur-, 
and  is  then  stopped,  the  Leyden  jars  .-nil  remain  charged,  and  a  fla-h 
will  occur  on  pushing  the  poles  toward  each  other. 

\\  hen  a  Leyden  jar  is  discharged  by  placing  one  end  of  an  insulated 
metal  rod  in  contact  with  the  oilier  coal  and  bringing  the  other  end 
near  the  knob  connected  with  the  inner  coat,  the  spark  which  is 
produced  does  not  completely  discharge;  the  jar.  and  after  a  minute 
or  two  a  smaller  spark  or  residual  discharge  may  be  obtained  in  the 
same  way. 

The  electric  spark  produced  by  the  discharge  of  a  Leyden  jar 
or  any  other  condenser  appears  like  a  .-ingle  flash,  lasting  quite  an 
appreciable  length  of  time.  Experiments  in  which  the  spark  i- 
observed  bv  means  of  rapid.lv  rev<  ilvmu1  imrr<  >rs  do  not  sin  >w  the  reflec- 
tion of  the  spark  as  a  bright  spot,  which  would  be  the  case  if  the  dis- 
charge were  instantaneous.  On  the  contrary,  the  image  appear- 
drawn  out  into  a  line,  and  measurements  which  have  been  made 
indicate  that  a  Leyden  jar  discharge,  between  bra-.-  knobs  five  milli- 
meters or  one-fifth  of  an  inch  apart,  lasts  about  one-twenty-four- 
thoii-andth  of  a  second.  The  same  kind  of  experiment  upon  a  buig 
spark  shows  that  it  begins  simultaneously  ;it  both  pole-,  and  is  visible 
later  in  the  middle.  Static  electricity  travels  through  the  air  and 
through  most  metallic  conductors  at  the  rate  of  ]ss.(H)n  miles  ;i  second. 
so  that  the  difference  in  time  between  the  appearance  of  luminosity 
at  the  middle  of  the  path  of  the  spark  and.  at  the  two  ends  is  very 
-  till  indeed.  The  discharge  take-  a  xigxai*  course,  just  exactly  as 
the  ca.se  with  the  lightning  flash,  because  of  the  varying  resist  a  i  • 
caused  by  the  condensation  of  the  :iir  before  it  in  different  parts  \<\ 
its  path.  A  spark  passing  through  a  part ial  va 
a  straight  litre, 

Oscillatory  Nature  of  Spark  Discharges.   -A  siiucl*1  spai 
by  a  Leyt  len  jar  represents  millions  of  t 
the   lightning    flash    across   a    mile   or 
oscillations.      Two    oppositely    but    eqtl 
bet  \ver-n    which    a    pith-ball    i-   su-pen  Je 
both   become  nenira.l   in    consequence1  o 
h    tia     '  fst  touch   ).  a 


30 


Mi:i>I<    VI.     KI.KCTRICJTY    AM)    KO.VH  i  K.N     HAYS 


I   IL_'.     111.        I'ith  h;,ll     M.-rilhitillK     1 


nt  this  negative  charge  is  communicated  to  the  pith-ball  and  carried 
ad'i >--  t  ii  f>.  I  ho  n cut  rah/ at  i<  m  of  a  Ley den  jar  charge  is  accomplished 
by  a  somewhat  analogous  sci'ics  oi  oscillations.  It  is  t  ho  enormously 

high  l'rc(jiiciicy  of  these  oscillations, 
millions  a  second,  t  hat  Divest  he  name 
to  "  high-frequency '  curi'ents.  This 
subject  will  be  dwelt  upon  in  an- 
<>t  her  chapter. 

Any  electric  spark  in  the  open  air 
produces  discharge  rnifx,  which  are 
described  elsewhere  and  have  some 
of  the  properties  of  the  .r-ray. 

The  Electrophorus.-  If  a  mass  of  melted  resin  is  poured  into  a  metal 
plate  and  allowed  to  cool,  it  may  be  charged  with  negative  electricity 
by  rubbing  it  with  cat's  fur.  If  a  metal  disk,  somewhat  smaller 
than  the  resin,  is  placed  upon  its  surface,  the  neutral  charge 
of  the  metal  disk  becomes  separated  into  a  positive  charge,  induced 
"ii  its  l<>wer  surface,  and  a  negative  charge,  on  its  upper  surface. 
While  the  disk  is  in  this  condition,  if  it  is  touched  by  the  finger  or 
some  other  grounded  conductor,  its  negative  charge  will  be  removed, 
and  an  addition  made  to  its  positive  charge1  (Fig.  20).  The  negative 
charge  on  the  res  in  i-  not  communicated  to  the  metal  disk  because  the 
rough  and  uneven  surface  of  the  resin  prevents  contact  except  at  a 
comparat ivelv  few  scattered  points.  '1  he  resin  is  so  poor  a  conductor 
thai  it-  charge  remains  fixed  on  the  different  parts  of  its  surface 
which  do  not  come  directlv  in  contact  with  the  metal  disk.  The 


1  !_•.    _'•  '.       '         •      •  _     '          •         '  •     :  :..  inis. 

negative  charge  mi   t  lie   resin   attracts  a  comparatively  great   charge 

o!   : "  - .  •  ;    e  elect  ric  it  y  1 1  it  o  1  he  disk  placed  on  it  s  surface  and  connected 

/      the  gr    •;•:•:.      The  positive  charge  on  the  disk  in  turn  exerts  an 

induct  ion   upon   t  lie     e-m ,  increa-ing  it  -  ne<_ra1  ive  charge  by  at  1  r act  ing 

negative    eh-d  rich  '      ;:     n      the    earth    through    the    outer    metal    plate, 

containing    the    re-   u.  had    better    not    be    insulated.      The 

•  •   •  t  her  Around  conned  ii  m.  is  to  be  removed  while  the  disk  is 

-•     .  '  .        I  he   (I  -    then    removed    bv    means    of    n>    ghi-s 

'    '  have  c|uit  e  a  ch;i  rge  i  if  pi  isil  ive  elect  rich  V. 

I  p  e   u-ed   to   t_ri  ve  a  -park.   ;i-   in   1  lie  dia.gr  am    (Fig.  '_'  1  i .   or  to 

.  •  •  a  Lev  ;cn  jar.      A  long  -ucce->ion  \\\  \  \<  -it  i\  c  charge-;  ma\'  thus 

lie   u       :    f-i  ]     ':   '  •  c   met  al   < : :  -  •  .   an  ;    u.-ed   to  charge  a  lar^'e   I  .e  v  len  jar. 

t  he   i  cigi  lal    -mgle    charge   of   negati\e   e'lec- 
iced    upon    the    re   in    b\     fridii  n.      'I  hi-    principle   i-   the 
'      •       '   '    '•  •        lern     I  at  ic  or  in  Hueiice  machine. 

THP:    MODERN    STATIC    OR    INFLUENCE    MACHINES 

The   a!  CM  ii    can    1 10   <  il  it  aineil    by    frid  ii  >\\    is 

•'  mp;irr-i]        il       he   Amount    of  work   recjuired   to   produce  it 


STATIC    ELECTRICITY 


31 


that  the  apparatus  dependent  upon  this  principle  is  impracticable, 
but  a  small  charge  of  static  electricity  originally  produced  by  friction 
may  be  so  increased  by  means  of  a  suitable-  induction  apparatus  as  to 
be-  powerful  enough  for  e;very  medical  purpose;. 

In  the  static  machine;  of  the;  simple;  friction  type;  a  positive;  charge; 
is  preulue-eel  upon  a  involving  glass  plate;  by  frict  ion.  This  positive; 
charge  is  carried  by  the;  glass  to  the;  place;  whe;re;  the;  metal  collecting 

comb  of  one  of  the;  poles  is  ne-ar  the  plate; 
(  Fig.  22).  The;  posit  ive  charge  upon  the  plate 
separates  the  neutral  e-harge-  of  the  e-omb  and 


>iiih 


prime  conductor,  inducing  a  negative  charge;  in  the;  comb  and  a 
positive  charge  in  the  pole  (Fig.  23).  The  negative  charge;  escapes 
from  the  points  of  the  comb  as  a  static  bree/.e  or  brush  discharge, 
which,  passing  to  the  surface  of  the  plate;,  neutralizes  the  positive 
charge  there  and  leaves  the  plate  ready  to  be;  recharged  by  friction 
at  anothe-r  part  of  its  revolution.  The  rubber,  of  course,  is  negatively 
charged,  and  is  e-onnected  with  the  othe^r  pole  of  the  machine. 


iir.  2-k-    Di:iirr:iiu  ol  inllurm'o  tvpc  ut  stulii'  inurhin    . 


In    one    tvpe   of    inlluence1    machine    there    arc    t\v<  |>!ale- 

pape>r  or  of  met  al  foil  [>asted  upon  two  separate  -t  al 
(Fig.  24).    These;  fie>ld-plate>s  are  slightly  charged     ".  \\ 
h.  with  neative  olectricitv.     A  third  insulated  [HIM-I-  oi 


32 

called  a  carrier  is  fastened  upon  a  revolving  glass  plate.  This  carrier 
is  iir<  'undei  1  or  connected  \vil  h  t  lie  cart  li  when  it  is  <  ipposit e  a .  and,  b  ke 
the  metal  disk  nt'  an  electrophortis,  will  ha\'e  a  small  charge  of  free; 
elect  rich  v  after  it  has  moved  past  «.  \\hen  it  has  made  part  of  a 
revi  ilut  ion.  a  collecting  brush  conies  in  contact  with  the  negatively 
charged  carrier.  This  collecting  brush  is  connected  with  the  negative! 
field  plate  >>.  to  whose  original  small  charge  is  added  the  major  part 
of  the  charge  brought  liv  the  carrier,  which  in  this  way  becomes  less 
full\"  charged.  ('< iiit  inning  its  revolution  the  carrier  comes  opposite 
the  negative  held  plate  //,  with  which  it  is  no  longer  in  connection, 
while,  nil  the  other  hand,  it  is  again  grounded.  I'nder  the  influence 
of  a  somewhat  increased  negative  charge  of  h  a  somewhat  stronger 
positive  charge  is  induced  in  the  carrier  -positive  electricity  being 
atl  r  acted  into  it  from  the  eart  h,  and  negative  electricity  being  repelled 
from  it  to  the  earth.  While  the  carrier  is  opposite  h,  this  positive 
charge  is  bnund  or  fixed  upon  the  carrier  by  the  attraction  of  the 
oppositely  charged  held  plate,  just  as  is  the  case  with  the  charge  upon 
the  two  coats  of  a  I.evden  jar.  After  it  has  revolved  past  h  and  is 
als"  no  Joim'er  grounded,  the  positive  charge  upon  the  carrier  becomes 
free  and  is  carried  by  a  collecting  brush,  which  comes  in  contact  with 
it  to  (i,  strengthening  the  positive  charge  already  present  in  that 
tield-plate.  \\ith  a  rapid  rotation  and  a  mechanic  construction 
which  permits  of  very  little  leakage;  of  electricity  by  conduction,  the 
field-plates  soon  acquire  a  very  powerful  charge. 

I'l'i'in  the  beginning  a  carrier,  when  negatively  charged,  gives  up 

onlv  a  certain   portion  of  n  <  charge  to  the  collecting  brush,  leading  to 

th"   negative   field-plate,    so  that    both    the  carrier   and    the   field-plate 

:  a'  e  !  he  same  charge  m  pro  port  ion  to  1  heir  si/e.      The  unappropria.t  ed 

negative   charge   upon    the   carrier   is   taken    up   hv   1  he   combs   of  the 

'•  conductor  before  the  carrier  reaches  the  part  of  its  revolution, 

'••     "  ••  .'   a'jfain  come-  un  ier  an   inductive  iniluence.      This  charges  the 

negative  p»le,   and   the  positive  pole  receivers  its  charge  in   the  same 

'.vay,    through    a   comb    applied    at    the    opposite    part    of   the    carrier's 

,'i<'!;.       1  !:e  two   poles   are   the   [daces   at    which   the  two  opposite 

'"••-."-'••    are    tieare-1     together,    and     where    1  hev    exert     their    greatest 

at ;  raci  ion  lor  each  ot  her,  and   \\' here  a  discharge  occurs  when  sufficient 

''•'  -    produced    to    overcome    the    resistance    of   the    intervening 

I  he    a'  o|     the    charge    in     the    opposite    pole    is    a 

:il    tactMf   in    the    pa--a^e   of   the    unappro[)fiat ed    charge   from    the 

;-'   '   '       '•   '•'''     •         '  '  '•    prime   conductor.      In   this   transfer   from 

'••'   ' ' '    prime  e   pn  >ce  -    may  be    regar<led    as   one   of 

'he  ca-e  iii   the  -imple  1'rict  ion   machine.       Instead 

hen    1  lie   ca rner    is   opposit e   one   of 

e-.    i  '     •..,••      in      •  .   •  '.     in;  chines   \\  hich    ha  ve    tin  >re 

'  '         e  ci  inneci  i>  .ji   made  bel  ween   the    t  w  i    oppo- 

•' ''  '    •  '          •  ir   of  neut  ralixinu;   1  irushes   j<  lined    1  >\-    a 

'  x.i-    '  '  alt  racted     iut  o    i:     t  he    po<il  ive    cha  rire    i  'f 

'    '  '  '•  '  '•   the   ti.  '_•;,'  r.  e  charge  ( if   hoi  h    i-   at  !  raci  ed 

I  ;  e    Toepler    machine 

'.   e.  \        '  •     -,'•     :  Hie       -  I;.   ."     |  [        | 

•    •    i  -    i  | ,  '  •  '    -      ,      •  , .     t 
i 


STATIC     KLKCTUICITY 


33 


twelve  indies  in  diameter,  upon  the  back  of  which  are  pasted  the 
field-plates,  two  pieces  of  paper  forming  curved  strips  al>out  two 
inches  wide,  with  their  outer  edge  about  an  inch  internal  to  the  outer 
edge  of  the  stationary  plate.  Kach  of  these  strips  occupies  about 
one-fourth  of  the  circumference  of  a  circle.  A  strip  of  sheet  metal 
is  pasted  directly  upon  the  glass  along  the  center  of  each  strip  of 
paper,  the  sheet  metal  forming  a  strip  about  half  an  inch  wide  and 
five  inches  long,  with  somewhat  larger  extremities.  The  revolving 
glass  plate  is  about  an  inch  and  a  half  less  in  diameter  than  the 
stationary  one,  and  is  at  a  very  small  distance  from  it.  I'pon  its 
front  surface,  that  is,  the  surface  away  from  the  stationary  plate, 
there  are  pasted  eight  carriers  strips  of  metal  about  three-fourths  of 
an  inch  wide  and  two  inches  long, 
arranged  in  the  direction  of  1  lie  spokes 
of  a  wheel.  As  this  plate  revolves 
these  metal  carriers  are  rubbed  by 
four  different  wire  brushes;  two  of 
these  are  neutralizing  brushes,  the 
other  two  appropriating  brushes  con- 
nected with  the  two  field-plates. 
There  are  two  combs  not  shown  in 
the  picture  for  collecting  the  unap- 
propriated charge  from  each  carrier, 
and  leading  it  to  the  field-plates  of 
the  Holtz  machine.  This  Toepler 
machine  is  operated  by  hand,  and  a 
few  turns  of  it  generate'  a  sufficient 
charge  to  enable  the  Holtz  machine 
to  start  up  promptly.  The  Toepler 
machine,  it  will  be  seen,  is  self-charg- 
ing: the  friction  of  the  brushes  upon 
the  metal  carriers  and  also  upon 
the  glass  surface  produces  sufficient 
electricity  to  start  it,  and  this  is 
rapidly  multiplied  by  the  induction 
which  characterizes  every  form  of  in- 
fluence machine. 

All  these  modern  types  of  static 
machine  are  capable  of  producing 
very  powerful  charges  when  a  num- 
ber of  large  plates  are  used,  a  high 
rate  of  speed  is.  produced  by  electric 
which  they  are  contained  are  air-tight,  and  the  machines  are  kept  free 
from  dtist  and  moisture.  The  large  powerful  machines  so  commonly 
used  in  America  are  capable  of  producing  very  much  better  results 
as  a  therapeutic  agent  and  for  the  operation  of  an  .r-ray  lube  than 
the  smaller  machines,  usually  made  in  Kurope.  which  can  be  lifted 
by  hand  and  are  hardly  more  than  laboratory  toys. 

The  Wimshurst  machine  (Fig.  -l>).  in  its  simplest  form,  consists 
ot  two  glass  plates  of  equal  size,  and  very  close  to  each  ot  her.  revolving 
in  opposite  directions.  Kach  has  a  number  of  metal  carriers  pasted 
upon  it.  and  these  also  serve  the  purpose  of  field-plates,  and  arc  on 
the  side  away  from  the  other  plate.  Kach  plate  has  its  own  pair  of 


the 


3-1 


neuirali/mg  brushes,  connected  by  a  brass  rod.  There  is  ;t  double 
collecting  comb  passing  from  each  prime  conductor  to  the  t\vo  glass 
plates.  The  comb  from  the  negative  pole  is  forked  and  extends  close 
to  the  -urt'ace  of  both  plates  and  receives  its  charge  a  carrier  on  each 
..f  the  two  plates  simultaneously.  There  are  no  special  field-plates 
and  no  appropriating  brushes,  bringing  a  charge  directly  from  the 
carrier  on  one  plate  to  any  part  of  the  other  plate.  The  initial  charge 
i-  produced  by  the  friction  of  the  neutralizing  brushes,  upon  the  glass 
plates  and  metal  carriers  A>  soon  as  any  of  the  carriers  become 
charged,  they  act  upon  those  of  the  other  plate  by  induction,  in  the 
way  described  as  takhm  place  in  the  Toepler  machine:  and  very  soon 
a  powerful  charge  i-  generated  and  may  be  seen  passing  across  the 
space  between  the  discharging  rods  connected  with  the  two  poles 
'Fig.  L'Ti  Like  the  Toepler  machine,  this  is  self-exciting,  and  is 
often  employed  to  <rive  the  initial  charge  to  a  Holtz  machine.  For 


':..-   purpose  it    i-   placed   inside  the  irlass  case  of  the  larger  machine 

<ri  veil    a    few   '  urns   i  iv    hand. 

The  Holtz  Machine    l-'iir.  L'SI.      In  this  \-ariety  of  influence  machine 

there  are  I    ,  LTe  fixed   field-plates  and   a  plain  revolving  glass  plate 

.:'•'-      Fit:.   _".h.      There    are    a    pair    of    combs    at    opposite 

''.•:-   •;••'••       rod     performing  the  office  of  neutrali/ing  brushes, 

nd    there    ..:••     •  iieciintr    ciimb,-    from    the    prime    conductors.      It    is 

'  '"•'  --  ir;     '         ,  an   ii    ':'::   chartre.   and   tortneri\'  this  was  done  by 

1    eaii-  ••      '      ;  "      rubber  excited   by   frictinii   and    held   against 

lie   lila--   plan-   revolveil.      It    i-   customary  now 

•    '•  .       '  \\  imsi  ursl    machine  inside  the  same  case 

.'••''•    i    •         charirc.       \   ' lern   1  loll  x  machine  is  made  ii] > 

-'••!•  •    fevoh-iim  and   -tationary   plate-,   u-uallv    filaced 

ei   e~  up    '    t  he  -a  ;    f  a  \lf.  ami  1  urned  by  an  elect  ric  or  Wat  er  mot  or. 

I'.    '     '  •         •          '     -mLrle   couple    i~    repre.-eiil  ei  I.        I  he   stationary 

le      -    in    t  Wo   -ep        ile   pi  iTl  i.  ins,    •/.    ti.   r.    ,1 ,    a!id    i  .    /'.   </./'.' 
.   i-     '•  •    .   <  •• :   '      i  he    ci  M  >den  r;i>e     f  1  hi     '    uchine  b\'  wooilen  ami  hard - 
rubbi  et i          n-ulate  1  hem.      They   do   not    come 


STATIC     KLKCTHICITY  oO 

in  contact  with  any  other  part  of  the  machine.  The  field-plates  are 
two  large  pieces;  of  paper  with  a  half-circle  of  sheet  metal  coyering 
the  paper  at  one  end.  and  turning  over  the  edge  of  the  glass  at  1  lie 
edge  where  the  revolving  glass-plate  first  meets  the  field-plate.  The 
field-plates  are  on  the  front  of  the  divided  stationary  glass  plate,  and 
so  are  the  semicircles  of  metal  which  are  pasted  upon  their  front 


exept    in    the    first    couple    of   the    Holtx    macliine.       I  he    ti 
combs  project    in   front    of  the  rovolvinn  plate  at    th.e  p 
liottom,  w'here  the  revolving  glass  is  iu-t   leaviim  the  ml 
field-plates.      The    collecting    coml.s    from    t!«e    [irime 


30 


uiul  .V  project  in  front  of  the  revolving  plate  at  plares,  at  oithor  side, 
where  the  reviving  glass  has  just  entered  the  influence  of  the  field- 
plates,  near  the  ed.ue  (if  the  metal  semicircles.  There  is  no  connection 
lietween  the  revolving  plate  and  1  he  stationary  plate  with  its  field- 
plate.  There  are  no  collecting  Brushes  to  carry  the  fret!  charge  on 
the  revolving  plate  to  the  field-plates,  hut  this  is  accomplished  by  a 
convective  dix-harijv  or  eliluve  lietwen  the  revolving  glass  plate  and 
the  i  net  all  ic  semicircle  connected  wit  h  each  field-plate.  The  revolving 
plate  lieing  of  irlas<.  is  itself  a  non-conductor,  and  is  made,  still  more 
s<  i  by  a  varnish  nf  shellac:  and  nothing  whatever  touches  or  rubs  over 
its  front  or  hack  surface.  At  a  certain  stage  any  one  portion  of  the 
revolving  da-s  plate  may  have  a  positive  charge,  which  it  has  received 
by  a  convective  discharge  from  the  combs  of  the  prime  conductor 
and  a  negative  charge  induceil  in  it  by  the  field-plate.  This  par- 
ticular part  of  the  revolving  trlass  plate  retains  these  two  charges. 


bound  upon  11-  sin-faces  by  mutual  attraction,  just  as  is  the  cast1  in  a 
directed  Leyden  jar.  where  the  positive  and  negative  charges  remain 
'if'"11  ;:-''  -'a--  after  the  outer  and  inner  metal  coats  are  removed. 
I.a'-h  successive  portion  of  the  revolving  glass  undergoes  various 
Taii-Iormat  ions  by  induction  and  bv  convective  discharges,  just  as 
were  revolvinj;  in  -pace  sejiai'ated  from  everv  other  part  of  the 
same  plate.  Kleftrifully.  each  part  is  separateil  as  long  as  t  he  glass 
•'i'"i  •  -hellace.l  -urface  are  t'ree  from  dust  and  moisture.  \Vhen 
!'''-''  '''  ndition-  are  nut  fulfilled,  the  Hnltz  machine  will  produce  only 
:t  feeble  dischartre,  and  fierliaps  none  at  all. 

\\hen  a  multiple  plate  Holt/  machine  is  charged,  it  will  not 
reverse  [loharity  -o  lofijr  a-  it  is  runnitm  and  the  sliding  rods  are 
separate.]  >everal  inches.  When  the  atmosphere  inside  of  a  Holt/ 
machine  ha-  considerable  moisture  in  it.  the  polarity  mav  reverse  if 
the  ~:  linjr  rods  an-  broiijilil  in  contact.  \\'hen  a  Holt/  machine  loses 
it.s  charire.  then  up-.n  recharging  it,  the  polarity  may  be  reversed,  but 


STATIC     KI.KI  TKIC1TY 


this  is  duo  to  the  fact  thai  the  polarity  of  the  charging  machine  has 
reversed.  The  Holt/  machine  itself  will  not  reverse  polaritv  as  long 
as  it  retains  the;  original  charge. 

It  must  l>e  noted  that  while  we  speak  quite  definitely  about  1  he- 
way  in  which  an  influence  machine  generates  electric  charges,  the 
subject  is  a  purely  speculative  one.  and  the  fads,  if  they  could  be 
known,  might  vary  considerably  from  our  conception  of  them.  That 
when  an  influence  machine,  even  with  the  latest  improvements,  is 
started  up,  one  pole  will  sometimes  he  the  positive  and  sometimes  the 
negative  is  very  curious. 

Any  of  the  influence  machines  may  be  made  with  plates  of  other 
material  than  glass;  hard  rubber  has  many  desirable  features:  it  dues 
not  attract  moisture,  and  is  not  so  heavy  or  so  apt  to  break  under 
the  strain  of  an  excessive  speed  of  rotation  as  glass.  On  the  other 


hand,  it  undergoes  a  slow  process  of  degeneration,  and  is  also  liable  to 
warp  and  lose  its  perfectly  flat  shape.  .Mica  plates  are  made  of  mica 
split  in  mfinitesimally  thin  pieces,  mixed  with  powdered 'shellac  or  a 
similar  substance,  and  subjected  to  an  enormous  pressure  while  healed 
to  the  proper  degree.  Machines  with  mica  plates  work  excellent  ly. 
and  while  one  would  Mippose  that  the  plates  wniild  disintegrate  in 
time.  1  he  manufact  urers  say  that  t  hev  have  never  had  a  plate  returned 
tot  hem  in  this  condit  ion. 

The  Paper  Disk  Static  Machine  'Fig.  MO). — The  static  mac1  h  p 
made  hv  the  Baker  Flectric  ('ompany  i-  a  Toepler  machine,  and  i- 
mclosed  in  a  glass  case,  but  usuallv  does  not  require  calcium  rhlnnd 
inside  the  case  to  absorb  moisture. 

A  suitable  machine  for  r-ray  work  i-  known  as  an  eight-]  re 
machine,  having  four  revolving  paper  disk.-  and  four  stationary  gl; 


3!>  Ml.DIt    \I.     Kl.Ki  TKK'ITY     AM)    KONTi.K.N     KA\S 

plates.  The  plates  make  'JDOO  revolutions  a  minute,  a  two-horse- 
power engine  or  motor  being  required  to  run  the  machine.  Kxeellent 
radiograph.-  of  the  t'oot  can  be  made  in  six  seconds,  and  of  the  chest 
in  thirty  seconds. 

Kach  paper  disk  is  made  of  about  '24  full-sized  sheets  of  bond 
paper,  coated  with  shellac  and  other  gums,  to  harden  the  shellac, 
for  the  latter  does  not  harden  unless  exposed  to  the  air.  The  whole 
mas-  is  compressed  between  hot  metal  plates  and  then  allowed  to 
cool  slowly  while  under  pressure.  The  result  is  a  disk  about  {  inch 
thick,  which  i-  practically  unbreakable.  It  sounds  like  a  piece  of 
iron  when  -truck  by  metal.  Moisture  has  less  tendency  to  condense 
upon  it  than  upon  glass.  and  the  plate  will  stand  the  strain  of  2000 
revolutions  a  minute,  while  the  normal  rate  with  revolving  glass 
plate-  i-  :•).">(  i  revolutions  a  minute. 

The  revolutions  being  five  or  six  times  as  rapid,  the  discharge  is 
more  nearly  continuous  than  from  a  glass  plate  machine.  It  is 
twentv  times  as  nearly  continuous  as  the  discharge  from  an  induction 
coil.  The  discharge  from  a  powerful  paper  disk  static  machine 
through  an  .r-riiy  tube  is.  therefore,  more  nearly  continuous,  and  the 
heating  effect  on  the  ant  icat  hode  is  very  great.  Some  tubes  will 
traiismii  Is  milliamperes  of  this  current,  but  after  about  thirty 
seconds  it  is  found  that  the  vacuum  has  dropped  to  such  a  degree 
that  the  .r-ray  generated  has  no  penetration,  (le.nerally  speaking, 
the  tubes  which  will  stand  the  discharge  for  half  an  hour  or  so  give 
excellent  Huoros.copic  images,  but  make  poor  pictures;  while  the  best 
radiographs  are  sometimes  made  by  tubes  which  will  stand  the 
current  for  hardly  thirty  seconds  without  breaking  down. 

wn  is  attributed  to  the  fact  that  the  platinum  is 
r    welded    to    the    surface    of   the    mass    of    copper 
for    heat    radiation.      The   cement    in   one   case,    or   the   flux 
the   other   case,    gives   out    gas   when    heated   and   lowers   the 

bes   have  been    made  with  an   anticathode  in  which  the  copper 
ng   i-  deposited   on   the  platinum   by  electrolysis;  the  platinum 
per-plated.      This  does  away  with  the  evolution  of  gas  from  the 
jusl    ment  i'  ined. 

noi  her  charact  erist  ic  of  the  discharge  is  its  comparative  freedom 
-napping.       I  hi-    is    seen    m    the    line    xigxag   sparks    which    pass 
e:i    the    prime    conductor-    of    a    static    machine    when    they    are 
ate  :  beyond  the  range  of  actual  white  sparks.       With  most   glass 
machines   there   is   considerable  of  this  effect    interfering 

This  snapping  is  a  sort 
the  amount  of  metal 
The  paper  disk  static 


apping  at  a  distance  of  over  thre 


of  violet   luminosit 


wever,   the  snapping  at 


ome     eteroraton,  owng 
ases  which  are     enerated 


a  composite  plate  i 


STATIC     KLKC'l'KICITV  39 

that  when  static  machines  are  made  having  more  than  two  revolving 
plates,  and  having  them  made  of  a  composite  material,  they  mav 
possibly  prove  unsatisfactory,  owing  to  the  fact  that  the  revolving 
plates  are  liable  to  perforate. 

The  Size  of  Static  Machines.-  For  ordinary  therapeutic  uses  a 
machine  with  eight  or  ten  revolving  plates  thirty  or  thirty-two 
inches  in  diameter,  and  making  .'•>()()  revolutions  a  minute,  is  sufficient. 
Such  a  machine  will  also  light  up  an  .r-rav  tube  so  as  to  make  possible 
a  fluoroscopic  examination  of  the  extremities,  or  a  radiograph  of  the 
same  parts  and  the  chest  (either  a  much  larger  static  machine  or  a 
transformer  is  required  for  practical  ./--ray  work).  Static  machines 
have  been  made  with  revolving  glass  plates  weighing  a  ton  in  the 
aggregate,  and  have  given  beautiful  results  with  an  .r-ray  tube.  A 
static  machine  with  sixteen  revolving  plates  thirty  inches  in  diameter 
is  powerful  enough  for  all  practical  purposes.  This  should  be  furnished 
with  a  half-horse-power  motor. 

Pole  Changer. — The  polarity  of  a  static  machine  cannot  be  volun- 
tarily changed,  but,  especially  for  .r-ray  work,  it  is  often  convenient 
to  use  a  pole-changer — a  jointed  hard-rubber  rod  by  means  of  which 
the  connection  of  two  wires  with  the  two  poles  of  the  machine  may 
be  changed  by  simply  reversing  the  position  of  the  rod. 

The  Care  of  the  Static  Machine. — The  modern  influence  machine 
gives  a  wonderfully  steady  output  when  in  good  order. --much  more 
uniform  than  the  current  from  the  best  induction  coil. — but  it  is 
very  sensitive  to  atmospheric  and  other  conditions,  affecting  the 
insulation  of  the  surfaces  of  the  plates.  The  machine  should  be 
completely  inclosed  in  glass  and  wood,  and  this  case  should  be  air- 
tight. The  room  in  which  the  machine  is  kept  ought  to  be  a  dry  one. 
and  one  on  the  second  floor  is  sure  to  be  better  than  one  in  the  base- 
ment. If  the  case  has  to  be  opened  for  repairs,  this  had  better  be 
done  on  a  clear  dry  day.  and  it  should  be  left  open  as  short  a  time  as 
practicable. 

The  muixtnrc  in  the  air  inside  of  the  case  has  a  tendency  to  collect 
upon  the  glass  plates,  and  with  it  also  the  atmospheric  dust  and  the 
metallic  dust  from  the  machinery  itself.  This  deposit  may  cause? 
such  a  lack  of  insulation  that  the  machine  will  produce  little  or  no 
discharge.  Several  different  ways  of  preventing  this  have  been 
suggested,  the  best  being  by  the  use  of  calcium  chlorid.  a  powerful 
absorbent  of  moisture.  A  generous  quantity  of  this  should  be  used. 
In  a  case  measuring  2  x  .'•>  x  4  feet,  and  containing  a  six-plate  static 
machine,  two  pounds  of  dry  calcium  chlorid  should  be  placed  in  deep 
open  vessels.  As  time:  passes  this  changes  from  a  powdery  while 
mass  to  a  dirt  y  slush  or  melt  ing  snow  appearance.  After  it  has  become 
completely  saturated  with  moisture,  of  course,  its  usefulness  is  at  an 
end.  It  may  be  regenerated  bv  drying  in  a  hot  oven,  or  it  may  be 
replaced  by  fresh  material.  Needless  to  add,  if  the  calcium  chlorid 
is  bought  in  quantities,  it  must  be  kept  in  sealed  tins  or  gla-s  until 
used.  A  larger  quant  it  v  will  be  needed  for  a  larger  machine.  A 
handful  of  calcium  chlorid  in  a  shallow  saucer  is  quite  inadequate 
to  the  purpose.  It  is  very  important  to  reduce  the  amount  oi  du<1 
produced  in  a  machine  to  a  minimum.  The  use  of  aluminum  in: 
of  brass  or  iron  for  the  pans  of  the  machine  inside  the  case  is 
recommended  wherever  practicable.  Aluminum  dors  not  o.\ 


40  MI. nil  Ai.   I.LKI  i  UK  n\    AND  Ki'NToiA    KAY> 

or  produce  much  metallic  dust.  With  a  properly  constructed  case 
achine  and  with  an  occasional  renewal  of  the  proper  amount 
of  calcium  chi»rid  a  static  machine  should  run  for  two  or  three  years 
with"1;:  any  fun  her  attention.  At  the  end  of  thai  time  it  may 
well  require  very  complete  overhauling.  The  inevitable  deposit  of 
metallic  dust  will  have  to  he  washed  off  of  the  plates  and  all  the  other 
interior  parts  of  the  machine,  with  a  light  additional  coat  of  shellac 
appliei  1  to  t  he  <j;la-.-  surfaces. 

Another  method  of  dealing  with  the  subject  of  moisture  is  to 
have  a  i£;i-  Hi-  i  it  her  flame  so  arranged  as  to  carry  a  current  of  hot  air 
;.:.  ;  products  •  f  combustion  into  t  he  case.  This  is  a  step  in  the  wrong 
direction.  1  b  .t  air  will  carry  more  moi-ture  than  cold,  and  watery 
vapor  is  one  of  the  products  of  combustion  when  uas  or  any  of  the 
inants  are  burned.  The  proof  of  this  is  readily  seen  on 
any  very  c»ld  day,  when  the  windows  of  a  room  in  which  a  number 
o:  <ra— jets  are  burning  will  be  covered  with  moisture,  while  those  in  a 
-  v.  h  the  <ras  ha>  not  been  burning  will  be  free  from  it.  \\ith 
;;  static  machine  benefit  might  be  obtained  from  heat  if  the  air  were 
heate  ,.  but  :epi  -eparate  from  the  products  of  combustion. 

1'his  can  be  easily  done  by  placing  one  or  two  :;_'  candle-power 
electric  lamps  inside  of  t  he  g!as>  case,  wit  h  a  switch  on  the  outside,  so 
that  they  can  be  turned  on  or  oft'  as  required. 

In  a  very  damp,  warm  climate,  a  >tatic  machine  may  be  thoroughly 
dried  in  fifteen  minute-  by  mean-  of  compressed  hot  air.  Inside  the  ease 
of  the  ma chini'  at  one  end  have  an  electric  toaster  supplied  with  the  regu- 
lar electric  liirhi  current.  At  the  other  end  pump  in  compressed  air  at  a 
;  r — ure  of  about  '2~>  pounds  to  the  square  inch.  This  can  be  done  every 
day  if  necessary.1 

Another   method   is  to   keep  from   _'()  to    loo  pounds  of  unslaked 

I-  inside  the  ca-e  of  a  static  machine.  This  works  excellently  as 
-t>rbent  of  atmospheric  moisture.  The  lime  must  be  wrapped 
thic  .'. — es  of  cloth,  t"  prevent  particles  from  flying  all 
•  •  e  ini  erii  IT  '  if  i  he  machine. 

I:.  a:,  emergency,  for  a  -ingle  session,  a  freezing  mixture  of  ice  and 

'   ::.    leep  Lrla--  or  earthenware  vessels.  -ndi  as  half  a  dozen  pre-erve 

ja?'-     pi  iced   inside  the  case,  will  cau.-e  the  moisture  to  condense  upon 

'    e   _  ve--ej-.   and   thus  iVee  the  machine  from   moisture.       If  irla-s 

-  are  u-ed   '»   put    the  ice  and   salt    mixture  in.   it    i-  always  well  to 
pi     •••  '     (•!       n   -aUccrs  or  ['late.-,  so  that   the  iir-t   condensation   will   be 
'  i    en     -..   r-  •       in    \vetting   the    bottom    of   the   case.      This    will 
o:rr-!,  -;t\  e  • :  e    ;:;    .  but  not  alwa\  -. 

•'  ;,•    -o    many   \vavs   are  recommended   for  dealing 
•          i-ture,  h    will  be  gathered  that  a  static  machine 
'  '•  .      1   rider  unfavorable  conditions   it    will   not 
::     >•    •    the   time   ihroimhout    thestunmer.      This   i- 
lie  -t  ,-tiic    :    achinr-  ha>  been  to  a  <:reat    ext  ent    ai  >an- 
:    electricity    for  the  ./'-ray.      There  is   good   reason 
er.    tiiat     a     proper) v    con-tructed    .-tatic    machine, 
e      •     \viil    \vork    regardless   of  en  \"ii'<  inmem .      Such 
N    P»o>ton    i-    in    a    ba>ement    oldv    a    lew    teet 
:  •    •      '  he   -i-  •     •  t'er.   and   -1  ill   ','.  <  >rks   perfectly. 

The  condition   of   the   atino-phere  <iut-ide  of  the  ca>e  of   the  >tatic 

•  <   .  A    \\.-i--.  M.  I)..  .I. ,,ii    ..i    \,!v.iti'-.--l  'rin.nqiculics.  October.  I'.MJ.  p.   117. 


STATIC    ELECTRICITY  41 

machine  has,  of  course,  much  to  do  with  the  condition  of  the  air  in- 
side, for  no  case  can  be  hermetically  sealed,  but  the  condition  of  the 
air  of  the  room  lias  also  an  effect  upon  the  efficiency  of  the  applica- 
tion of  the  charge  after  it  has  been  generated  by  the  machine.  If  the 
air  is  very  dam]),  it  ceases  to  be  a  good  insulator,  and  much  of  the 
charge  leaks  away  from  the  prime  conductors  by  a  convective  dis- 
charge. The  ideal  room  would  be  one  through  which  the  refrigerating 
pipe  ran  in  summer,  reducing  the  temperature  of  the.  air  to  between 
<)0J  and  70°  F.,  and  causing  much  of  its  contained  moisture  to  con- 
dense as  a  thick  layer  of  whit  e  frost  upon  t  ho  cold  pipes. 

All  exposed  metallic  parts  should  be  round  and  polished  and  kept 
clean.  Metallic  points  or  particles  of  dust  would  dissipate  the  charge 
by  convection,  \\herever  any  metallic  parts  of  the  machine  which 
conduct  electricity  pass  through  the  case,  they  should  not  come  in  con- 
tact with  wood,  but  should  be  insulated  by  hard  rubber.  While  wood 
is  a  poor  conductor  of  electricity,  the  extremely  high  voltage  possessed 
by  static  electricity  requires  the  most  perfect  possible  insulation. 

Starting  an  Influence  Machine.— In  starting  a  Holtx  machine 
provided  with  an  auxiliary  Wimshurst  or  Toepler  machine,  the  dis- 
charging rods  should  be  an  inch  or  two  apart .  and  after  t  he  motor  has 
been  turned  on  and  the  glass  plates  have  begun  to  revolve,  the  Toepler 
machine  should  be  given  a  few  turns  by  hand.  Soon  a  series  of  sparks 
will  begin  to  pass  across  between  the  discharging  rods  of  the  Holtz 
machine.  After  this  the  Holt/  machine  may  be  allowed  to  run  alone. 
It  may  happen  that  the  Holtz  machine  ret  ains  its  charge  from  the  last 
time  it  was  used,  and  in  that  case  it  is  not  necessary  to  give  the 
preliminary  turns  to  the  \\imshursi  or  Toopler  machine.  If  the 
Holtz  machine  refuses  to  produce  a  discharge  in  Inn  or  damp  weather, 
the  difficulty  may  often  be  overcome  by  disconnecting  the  machine 
from  the  ground  or  from  the  platform-  in  other  words,  removing  any 
means  of  conducting  away  the  discharge.  The  maximum  efficiency 
of  an  influence  machine  can  never  be  obtained  without  a  certain 
external  resistance,  and  this  is  most  effectively  provided  by  making 
it  necessary  for  the  discharge  to  take  place  across  an  air-gap.  \\ith 
the  discharging  rods  together,  of  course,  there  is  no  external  resistance 
at  all.  and  with  the  patient  directly  or  indirectly  connected  with  the 
machine,  the  electricity  finds  so  ready  an  escape  by  (-(induction  and 
convection  that  the  external  resistance  becomes  very  much  less  than 
it  would  be  if  a  charge  could  escape  only  from  the  bare  discharging 
rods  separated  bv  an  air-gap.  If.  then,  the  connections  are  all  made 
for  the  treatment  of  a  patient  and  the  apparatus  refuses  to  develop 
a  charge,  the  difficulty  may  often  be  overcome  by  disconnecting  the 
conductors  leading  from  the  static  machine,  and  separating  the 
discharging  rods  about  an  inch.  The  necessity  for  a,  sufficient  external 
rc.-istance  in  order  to  obtain  the  maximum  discharge  H  the  reason 
that  spark-gaps  often  have  to  be  placed  in  the  circuit  with  an  .r-ray 
tube  excited  by  a  static  machine. 

Accessory    Apparatus    for    Treatment    by    Static    Electricity. 
insulated  platform  should  be  of  wood,   measuring  about   t\vo  by 
feet,  and  with  glass  legs  about  nine  inches  high,  which  should  be 
free    from    dust    and    moisture,    either    of    which    would    reduce 
insulating  qualities.      The  platform  should  not   be  in  contact   with 
other  object,  and  not  near  enough  to  anything  else  to  lose  part 


42 


MEDICAL    ELECTRICITY    AND    ROXTdEX    RAYS 


electric-  charge  by  convection  or  a  brush  discharge  to  neighboring 
objects.  A  connection  is  generally  made  from  one  pole  of  a  static 
machine  by  means  of  a  xhcphcrd'*  crook,  a  brass  rod  five  feet  long, 
which  hooks  over  a  prime  conductor  and  rests  upon  the  platform. 
A  square  piece  of  sheet  metal  an  eighth  of  an  inch  thick  lies  upon  the 
platform,  and  the  shepherd's  crook  may  rest  upon  this  or  upon  the 
wood,  at  a  variable  distance  from  the  patient's  chair  (Fig.  31).  One 
leg  of  the  chair  mav  rest  upon  the  metal,  or  they  may  all  be  at  a  varia- 
ble distance  from  the  metal  plate.  Then,  again,  the  patient's  feet 
may  rest  upon  the  wooden  platform  at  a  variable  distance  from  the 
metal  plate,  or  they  may  rest  upon,  the  latter.  These  different 
combinations  regulate  t he  strengt  h  of  a  charge  received  by  the  patient 
seated  upon  the  platform,  by  varying  the  resistance  through  which 
the  charge  must  pass  to  reach  him 

The  cnnrit  i-  a  ring  of  brass  about  eleven  inches  in  diameter,  with 
a  series  of  points  projecting  downward.  It  is  extended  above  the 
patient's  head  bv  a  brass  rod  attached  to  the  woodwork  of  the  top 
of  the  case  of  the  machine,  and  its  height  is  adjustable.  It  may  be 
connected  with  the  pole  which  is  not  connected  with  the  insulated 
platform,  or  it  may  be  grounded.  Brass  chains  are  used  for  making 

•  and  various  other  connections  between  the  static  machine  and 

cces.si  iry   apparatus. 


I  >ircrt  method. 


I.'  i<li  n   jii       of  different     sixes    are   arranged   to  be   hung   from   the 

pole-   ni    the   machine,    or  are   placed   upon   a  shelf  at    the   front    of  the 

ca-e.    -i     arranged    that    two    I.eyden   jars  rest    upon    it.       If  the    Levden 

jar  -park  is  de-ired.  t  he  out  side  coatings  of  t  he  two  jars,  are  connected 

i'"    mean-  <>;  a  -eparato  rod:  or  some  machines  are  so  constructed  thai 

'hi-  rod  i-  mounted  under  the  shelf  in  the  form  of  a  lever.      When  this 

Cement    ;-  il~ed,   there  is  a  label   marked  "sparks"  so  placed  that 

the  handle  i.-  in  a  line  with  it.  the  rod  underneath  connects  the 

out-ide  coatings  of   the    two    jars.       If    the     I.eyden    jar    spark    is    not 


STATIC    ELECTRICITY 

desired,  it  is  always  best  to  remove  the  Leyden  jars  from  connection 
with  the  pole  pieces  of  the  static.  This  is  advisable  for  two  reasons: 
first,  that  when  they  are  connected,  even  though  the  outside  coatings 
are  not  connected,  still  the  Leyden  jars  impart  a  sharp  quality  to 
the  current  administered  to  the  patient,  which  is  usually  very  un- 
desirable; second,  when  the  jars  are  left  in  connection,  it  is  pos- 
sible that,  inadvertently,  they  may  become  connected  so  that  the 


carbon  point:  .">,  bra>s  point:  t>,  brus>  ball;  7,  bra-.s  bru>h;  S,  chain-holder;  '.»,  cord-,  liim- 


paliont  would  receive  the  discharge  from  the  two  jars,  which  would 
give  a.  very  violent,  shock.  As  this  is  absolutely  avoided  by  ha\  in<: 
the  jars  removed,  it  is  to  be  recommended. 

A  N<  /  of  (  h'ctradcs  (Fig.  o-1   have  insulated  wooden  or  hard-rubber 
handles,  and  a  metal  ring  for  the  attachment   ot   a  chain  conduct 
the  charge  to  or  from   the  electrode.      These  electrodes   tern    nate 
different  ways    -one  has  a  metal  point,  am  a  her  has  about    -1 '  p: 
pointed  brass  rods;  another  has  a  gas-carbon  extremity :  another 


44 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


a  two-inch  brass  ball:  another  a  two-inch  wooden  ball;  another  has 
a  brass  roller.  There  are  two  sponge  electrodes  with  heavily  insulated 
handles  and  a  pointed  wooden  electrode. 

A  chain  /tuldi  r  with  an  insulated  handle  is  of  brass,  in  which  a 
single  open  turn  has  been  made,  so  that  it  can  easily  be  hooked  around 
the  chain  leading  to  the  electrode.  It  enables  the  operator  to  keep  the 
chain  from  contact  with  the  patient  or  any  other  object,  and  so  prevents 
shock  or  loss  of  electricity. 

A  c<mc(  nti'dtur  i  Fig.  :!:!>  is  a  brass  rod  mounted  on  a  metal  tripod, 
and  so  arranged  that  its  pointed  extremity  may  be  directed  toward  any 
part  of  the  patient.  A  chain  leads  to  it  from  one  pole  of  the  machine 
or  froin  the  ground. 

( >ne  way  of  measuring  the  voltage  of  a  static  machine  is  by  noting 
the  length  of  a  -park  which  will  pass  between  the  discharging  rods 
while  the  machine  is  not  connected  with  any  other  object.  The 
distance  across  which  a  spark  or  disruptive  discharge  will  take  place 
rhroutih  the  air  depends  on  the  voltage  or  electric  tension,  and  also 
upon  the  nature  of  the  discharging  surfaces.  A  spark  S  mm.,  or 
of  an  inch,  long  between  polished  metal  balls  o  cm.,  or 
'iie-<|iiarter  inches  in  diameter,  represents  a  tension  of  about 
ills.  Other  estimates  covering  a  variety  of  conditions  vary 
nix)  to  :;.">. i  mo  volts  per  inch  of  spark  length.  This  has 
reference  to  the  -park  which  passes  completely  across  with  a  clear 
ud  sound,  and  not  to  the  brush  discharge,  which  is  seen  when  the 

poles  are  very  far  apart,  and  which 
is  visible  as  a  complete  bridge  over 
the  u'ap  only  when  the  room  is 
darkened.  Without  the  I.eyden 
jars  there  is  perhaps  not  a  very 
.-harp  line  in  t  he  case  of  static  elec- 
tricity between  the  true  disruptive 
discharge  and  the  convective  dis- 
charge, but  with  the  Leyden  jars 
and  a  rod  connecting  their  outer 
coat-,  there  is  no  mistaking  the 
disruptive  discharge  or  true  sparks 
for  anything  else.  However,  it  is 
the  discharge  from  the  bare  poles 
which  it  is  important  to  measure, 
and  which  indicates  the  voltage  or 
1  he  difference  in  potential  between 
1  he  poles.  The  volt  age  produced  by 
a  static  machine  can  never  greatly 
exceed  that  represented  by  a 
spark-gap  of  half  the  diameter  ot 
the  revolving  plates,  or  the  distance 
bet  ween  t  lie  nearest  charged  met  al- 
lic  parts  usually  the  discharging 
I'his  i-  especially  true  of  small  machines  having 
\  machine  \vas  exhibited  in  Washington  which 
Lrla--  plates,  thirty-two  inches  in  diameter. 
!re  ;  and  !;;iv  revolutions  a  minute,  developing 
nchc-  lonsi.  In  the  winter  time  we  frequently 


STATIC    ELKCTRICITY  -t.~i 

have  machines  having  ten  or  twelve  revolving  glass  plates  thirty-1\vo 
inches  in  diameter,  that  will  give  a  spark  seventeen  to  seventeen  and 
one-half  inches  long.  More  than  that,  the  statement  refers  only  to 
the  Holt/  type  of  machine.  The  Toepler-IIolt/  type,  which  is'  the 
type  used  by  the  mica  plate.  Bet/,  and  other  Chicago  manufacturer-, 
will,  as  a  rule,  develop  a  spark  one-third  the  diameter  of  the  revolvinu 
plate.  No  matter  how  efficient  a  static  machine  may  he,  the  voltage 
is  limited  as  above,  just  as  the  pressure  in  a  steam-boiler  is  limited  by 
the  safety-valve.  The  hottest  fire  cannot  produce  a  threat er  pressure 
than  is  required  to  raise  the  safety-valve.  With  the  static  machine, 
if  there  is  a  tendency  to  produce  a  higher  voltage  or  pressure,  the 
resistance  of  the  intervening  air-gap  is  overcome,  and  ;t  discharge 
takes  place,  limiting  the  voltage  to  the  specified  amount.  In  applying 
electricity  produced  by  a  static  machine  the  voltage  can  be  regulated 
by  the  speed  at  which  the  revolving  plates  are  rotated. 

The  Tension  of  Static  Machines.     The  discharging  distance  between 
two  metallic  spheres  1  cm.  in  diameter  is  different  for  varying  tension-. 

DISTANT!-:     OK     THK     T\vo 
SPHEKES. 

C'EXTIMKTKKS.  l\cm-:s. 

0.1 
0.5 
.0 


The  above  table  is  compiled  from  Joubert's  "Train''  d'Klec'trieitt'." 

When  one  pole  of  a  static  machine  is  grounded  and  the  other 
insulated,  the  potential  of  the  latter  rises  to  twice  the  figure  it  ha>i 
when  both  poles  were  insulated.  The  pole  that  is  grounded  has  a 
potential  of  zero,  and  the  other  has  its  potential  doubled,  so  that  the 
original  difference  in  potential  is  maintained. 

The  Efficiency  of  Static  Machines.  A  test  of  a  Holiz  machine  has 
been  made  by  Professor  Samuel  Sheldon,  of  Brooklyn.  New  ^ 
in  which  the  efficiency  was  shown  to  be  more  than  MO  per  cent. 
static  machine  was  run  by  a  one-quarter  horse-power  electric  m 
so  that  the  power  applied  was  accurately  known.  The  poles  of  this 
static  machine  were  connected  with  the  poles  of  another  static  machine 
which  was  not  provided  with  a  motor.  '1  lie  discharge  oi  static  elec- 
tricity through  the  second  static  machine  caused  its  glass  plates  to 
revolve  rapidly  in  a  con.1  rary  direction,  and  the  power  thus  generated 
was  measured  by  means  of  the  brake  resistance  which  it  would  over- 
c<  mie. 

The  Output  of  Static  Machines.  The  output  of  a  static  machine 
is  the  quantity  of  electricity  which  the  sparks  carry  across  between 
the  two  balls  in  a  second.  It  varies  according  to  the  efficiency  oi  the 
machine,  between  ,.-,!..,  and  ,.1,-,  or  more  of  a  coulomb.  This  is  equiva- 
lent to  a  current  of  from  ,',,  to  1  or  more  milliamperes. 

iMtic's   hottlr   for    measuring   the   output    of   a   static    machine   give- 
the  output    in   microcoulombs   per  second,    which    is   equal   to   milhan. 
peres.      The  calculation   is  based  upon   the  capacity  ('     in    microfarad- 


40 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


of  the  Levden  jar  (Lane's  bottle\  the  potential  V  in  volts  required  to 
-park  across  the  air-gap  of  the  Lane's  bottle,  and  X,  the  number  of 
-parks  per  second.  The  output  1)  in  microcoulombs  per  second  is 
given  by  the  formula - 

D  =  NVC. 

The  distinction  between  quantity  and  potential  or  voltage1  is  illustrated 
by  the  steam  engine.  In  the  boiler  the  pressure  is  so  many  pounds  to 

t  he  si  |  u  are  inch,  wit  limn  reference  to  t  he  size  of  the  boiler  or  t  he  amount 
of  water  converted  into  steam  in  a  certain  time;  the  last  two  elements, 
without  regard  to  pressure,  convey  the  idea  of  quantity.  A  static 
machine  with  sixteen  revolving  plates  will  generate  a  much  greater 
of  electricity  than  one  with  only  four  revolving  plates,  and  so 
achine  revolving  at  a  higher  rate  of  speed  than  another,  but  if 
's  are  of  the  same  diameter  and  the  construction  and  insulation 
llv  perfect,  the  voltage  produced  will  be  the  same.  A  machine 
with  a  greater  number  of  plates  and  a  more  rapid  rate  of  revolution 
will  produce  a  better  effect  by  maintaining  a  more  constant  supply  of 
elect  rich  v  at  a  cert  ain  potential,  making  up  in  this  way  for  the  constant 
losses  1>\  convection  and  conduction.  The  quantity  of  static  electricity 
in  a  charged  bodv  may  be  measured  by  the  repulsion  it  produces  upon 
a  similarlv  charged  body,  or  its  attraction  for  one  oppositely  charged. 
The  force  exerted  varies  directly  as  the  charge  and 
inversely  as  the  square  of  the  distance,  but  the 
latter  fact  is  mly  exactly  true  between  points 
and  not  between  extensive  surfaces. 

Coulomb's  torsion  balance  (Fig.  oT)  consists 
of  a  glass  case  containing  two  metallic  squares, 
one  fixed  and  one  fastened  to  a  rod  suspended 
horizontally  by  a  wire;  both  metal  squares  are 
similarly  and  equally  charged,  and  the  insulated 
handle  at  the  top  of  the  suspension  wire  must 
be  turned  a  certain  distance  in  a  direction  op- 
posed to  the  force  of  repulsion  in  order  to  bring 
the  horizontal  rod  into  the  standard  position. 

From  the  amount  of  torsion  or  twisting  of  the  wire  can  be  calculated 
t  he  amount  o|  elect  ricit  y. 

1  he  tfutiilnifit  < /<  rl  rnnn  t<  r  is  so  called  because  the  re 
are  quadrants  or  quart  ers  of  a  circle.      These  deflect  an  a  I 
-uspended    by   a    line  wire,   and  the  degree  of  deflection    i.- 
a  mirror  observed  through  a  telescope. 

e  m  measuring  the  dosage  of  static  electricity  a  piece  of  sheet 
n   inch  -'qiuire  is  applied   to  a  given   part   of  the  patient   by 
in-ulated    handle.      h    receives  a   charge  proportional    to 
I  he  charge  at   that    part   of  the  patient,  and  tins  is  carried 
o--  a-   possible  to  I  he  electrometer.      The  carrier  is  placed 
projecting  trom   the  top  of  a  gla.-s  case,  and   coin- 
mean-  ill   a  metal   rod   with  the  electrometer  vanes  inside 


Arrangement    of   Static    Machines.      F 


w 


th 


STATK       KLKCTHICITY 


17 


48 


MEDICAL    ELECTRICITY    AND    R()NT(;EN    RAYS 


illustrated  a  brass  chain  is  seen  hanging  from  the  connecting  rod  and 
extends  to  earth  connection.  The  two  discharging  rods  of  the  static 
machine  are  separated  by  about  nine  inches,  and  the  sparks  (Fig.  36) 
were  passing  across  at  the  rate  of  about  two  a  second.  The  picture 
was  taken  with  an  exposure  of  fifteen  seconds,  and  shows  the  path  of 
all  thes<>  different  sparks.  It  will  be  noted  that  the  sparks  from  the 
positive  pole  start  off  practically  in  a  single  straight  line,  and  become 
divergent  at  a  distance  of  about  an  inch  from  the  terminal,  so  that 
thi-  picture  of  a  number  of  successive  sparks  reproduces  the  familiar 
fox-tail  appearance  of  the  brush  discharge,  which  takes  place  from  the 
po>itive  terminal  when  the  Leyden  jars  are  not  used.  Even  then, 
perhaps,  the  fox-tail  appearance  is  due  to  a  very  rapid  succession  of 
single  sparks  following  the  paths  indicated  in  the  present  picture.  It 
looks,  however,  like  a  simultaneous  group  of  sparks.  The  positive 
terminal  shows  a  number  of  little  green  stars  on  the  surface  of  the  metal, 
and  t  he  discharging  spot  may  be  displaced  by  a  bit  of  wood  like  a  match. 
The  negative  end  of  the  succession  of  sparks  shown  in  the  picture  leaves 
the  terminal  from  quite  a  wide  distribution,  just  as  was  the  case  in  the 


negative  breexe  about  the  Leyden  jars.  The  negative  terminal  shows  a 
pure  violet,  with  only  one*1  in  a  while  a  white  spark  right  on  the  surface 
of  tin-  metal.  At  the  lower  left-hand  corner  of  the  picture  are  seen  the 
two  open  dishes  of  pure  calcium  chlorid.  Kach  of  these  contains  a 
pound,  and  the  machine  has  never  failed  to  work,  winter  or  summer. 
The  broad  white  sector  is  one  of  the  field-plates  on  the  foremost  of  the 

lows  the  distribution  of  a  succession  of  sparks,  the 
g   the   negative  and   the   right    the   positive  terminal 
The  distance  was  six  inches,  and  connected  Leyden 
All  the  sparks  are  united  in  a  single  trunk  at   the  (  •  ) 

SOME   PRACTICAL   ELECTRIC   UNITS 

For  electric  measurements  the  fundamental  units  are  the  centimeter, 
for  length,  the  <ira/n.  for  mass,  and  the  wcor/d,  for  time;  these  forming 
the  ( ',  ' '. .  S.  'centimeter,  gram,  second)  system. 

An  ohm   is   the   resistance   to   tin-   passage  of  electricity  offered   by  a 


STATIC    ELECTRICITY  4() 

column  of  mercury  lOG/V  centimeters  high  and  1  square  millimeter  in 
cross-section,  at  a  temperature  of  0°  ('.  It  is  about  the  resistance  of 
a  mile  of  copper  trolley  wire  or  of  a  single  foot  of  Xo.  40  (American 
gauge)  copper  wire.  Iron  has  about  six  and  one-half  times  the  resist- 
ance of  copper. 

An  ampere  is  the  unit  of  electric  current.  It  decomposes  0.0001)4.") 
gram  of  water  per  second.  It  will  deposit  0.001  1  IS  gram  of  silver  per 
second  in  an  electroplating  cell.  A  milliampore  is  a  thousandth  of  an 
ampere. 

A  coulomb  is  the  unit  of  electric  quantitv;  it  is  the  amount  of 
electricity  carried  by  a  current  of  1  ampere  in  a  second. 

A  volt  is  the  unit  of  potential:  it  is  the  electromotive  force  which 
will  maintain  a  current  of  1  ampere  in  a  conductor  whose  resistance 
is  1  ohm.  A  standard  Daniell  cell  produces  about  6  per  cent,  more  than 
one  volt. 

A  farad  is  the  unit  of  electric  capacity.  It  is  the  capacity  defined 
by  the  condition  that  1  coulomb  charges  it  to  the  potential  of  a  volt: 
a  microfarad  is  a  millionth  of  a  farad.  These  latter  measurements 
are  somewhat  analogous  to  the  bushel  and  (part  and  cubic  foot  of 
ordinary  measurements.  A  condenser  which  is  of  a  capacity  of  one- 
third  of  a  microfarad  must  contain  1200  square  inches  of  tin-foil,  and 
wrill  require  one-third  of  a  millionth  part  of  a  coulomb  to  charge  it  to  a 
potential  of  one  volt. 

A  condenser  of  one-half  microfarad  capacity,  as  required  for  a  half- 
inch  induction  coil,  forms  a  block  of  tin-foil  and  paraffined  paper  about 
one-half  inch  thick,  and  four  and  one-half  inches  wide,  by  six  inches 
long. 

Other  Measurements  of  Static  Electricity. — A  measurement  of 
static  electricity  by  the  electrometer  indicating  attraction  or  repulsion 
is  really  a  test  of  its  tension  or  voltage,  rather  than  of  its  quantity  or 
amperage.  The  latter  is  exceedingly  small,  but  it  is  perfectly  possible 
to  measure  it.  For  example,  a  number  of  discharges  from  a 
Leyden  jar  of  a  certain  si/e  will  decompose  a  very  small  amount 
of  water,  and  the  result  in  hydrogen  and  oxygen  gases  can  be  measured. 
Another  example  is  seen  in  the  test  which  the  author  applies  for  deter- 
mining which  is  the  positive  and  which  is  the  negative  pole  of  a  static 
machine  in  operation. 

The  pole  detector  is  a  sealed  glass  tube  with  leading-in  wires  of  plati- 
num, and  nearly  full  of  some  liquid,  such  as  a  solution  of  iodin  in  water 
and  iodid  of  potassium,  which  becomes  colored  at  t  he  negative  pole  when 
the  liquid  is  decomposed  by  the  passage  of  an  electric  current.  Kven  with 
a  static  machine  the  discoloration  is  distinctly  visible,  and  serves  as 
a  reliable  test  of  polarity,  but  both  of  these  tests  for  quantity  indicate 
such  an  exceedingly  minute  amount  of  chemic  change  that  the  thera- 
peutic effect  of  static  electricity  is  evidently  not  dependent  upon  an 
electrolytic  action  upon  the  tissues  or  fluids  of  the  body,  thai  is,  except 
as  will  be  subsequently  seen  in  a  subatomic  relation.  This  would  m>t 
be  discoverable  by  the  ordinary  means  of  chemic  analysis. 

Nevertheless,  as  applied  to  machines  having  eight  or  more  revolving 
plates,  the  polarity  of  the  static  current  has  a  most  decided  effect  in  the 
treatment   of  certain  forms  of  headache.      One  pole  over  the  head  v 
increase  the  headache,  while  reversing  and  putting  the  othr-r  pole  over 
the  head  will  relieve  the  headache.      In  using  static  electricity  lor  ; 
4 


Ol)  MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

countorirritiint  effect  we  always  make  the  electrode  negative,  and  the 

difference  in  the  effect  is  easily  noticed  by  the  patient.  "\Yhen  the 
electrode  is  negative,  it  feels  like  a  stream  of  fine  sand  striking  against 
the  skin,  whereas  when  the  electrode  is  positive,  it  feels  like  a  cool 
bree/.e  blowing. 

Another  form  of  treatment  in  which  the  polar  effect  is  most  marked 
is  what  is  known  as  the  ir<ire  current.  You  will  find  that  most  authors 
speak  most  favorably  about  connecting  the  positive  pole  with  the 
patient.  A  still  further  indication  of  the  polar  action  is  in  the  operation 
of  an  .r-ray  tube. 

A  d'Arsonval  milliamperemeter,  dependent  upon  the  deflection  of 
a  suspended  electromagnetic  coil,  may  be  used  to  measure  the  amperage 
of  a.  static  discharge  as  applied  to  excite  an  .r-ray  tube,  and  will  perhaps 
indicate  the  pretence  of  from  the  fraction  of  a  milliampere  to  two  or 
three  or  more  milliamperes.  A  hot  wire  milliamperemeter  can  also  be 
made  satisfactorily  to  record  these  very  small  currents.  In  the  case  of  a 
discontinuous  discharge  like  that  from  a  static  machine,  it  is  very  doubt- 
ful, however,  whether  the  milliamperemeter  indicates  the  true  amount 
of  electricity  which  is  being  transferred,  although  it  does  so  when  it  is 
used  to  measure  a  continuous  current,  like  that  from  a  voltaic  battery. 

The  amount  of  force,  required  to  rotate  the  glass  plates  in  a  static 
machine  has  to  overcome  two  factors — the  ordinary  frictional  resistance 
to  the  motion  of  that  amount  of  glass,  and,  second,  the  resistance  due 
to  the  attraction  of  the  two  forms  of  electricity  for  each  other  and  the 
power  required  to  separate  them.  In  a  crude  experiment  by  the  author 
a  six-plate  Holtz  machine  run  by  a  one-twelfth  horse-power  electric 
motor  showed  a  speed  of  rotation  2  per  cent,  greater  before  the  machine 
had  been  charged  than  afterward.  In  other  words,  about  one-fiftieth 
of  the  power  was  apparently  consumed  in  the  actual  separation  of  the 
electricity  into  positive  and  negative  charges.  It  is  an  established 
fact  that  the  amount  of  power  is  the  same  whether  in  the  form  of 
mechanic  motion  or  of  electricity,  so  that  in  the  case  of  the  static 
machine  all  but  about  '•)()  per  cent,  of  the  power  put  into  it  is  wasted. 
This  makes  the  static  machine  the  least  economic  of  all  sources  of 
electricity,  and  it  has  no  industrial  application  at  all.  The  other  two 
irreat  sources  of  electricity  cliemic  action  and  electromagnetic  induc- 
tion convert  a  greatly  vaster  percentage  of  the  power  consumed  into 
elect  rich  y.  and  where  high  volt  ages  are  necessary,  these  may  be  obtained 
with  practically  no  loss  by  means  of  coils  and  other  converters  which 
modiiv  the  electricity  from  these  sources. 

\  nl/<ii/<  or  potential  or  electromotive  force  is  the  force  which  tends 
to  cause  electricity  to  pass  between  two  points  so  as  to  cause  a  union 
of  their  charges,  positive;  and  negative,  producing  a  complete  or  partial 
neutralization.  In  the  ca>e  of  static  electricity,  voltage  is  chiefly  of 
importance  in  determining  the  distance  across  which  a  charge  will 
lla-li  in  the  open  air.  or  the  way  in  which  it  will  pass  through  the  partial 
vacuum  of  an  .r-ray  tube.  In  the  case  of  the  lesser  voltage  and  vastly 
t  er  am  per  age  oi  dynamic  electricity,  volt  age  is  chief  I  v  of  importance 
quantity  of  electricity  which  will  pass  through  a 
having  a  cert  am  re<i<t  ance. 

the  tads  regarding  vohage  and  amperage  may  be  typified 
long  pipe  leading  from  it.      When  the 
same  level   as  that    of  the  water  in   the 


STATIC    ELECTRICITY  51 

reservoir,  there  will  be  no  How  in  either  direction,  and  the  condition  is 
analogous  with  that  of  an  uncharged  conductor.  When  the  bag  is 
raised  from  the  ground,  the  water  will  begin  to  flow  through  the  tube 
if  the  other  end  is  open,  or,  if  that  is  closed,  the  water  will  bounder 
a  certain  pressure,  producing  a  tendency  to  motion  if  an  opening  were 
made.  This  condition  represents  the  case  of  dynamic  electricity 
produced  by  a  batten-  or  dynamo,  and  causing  a  current  of  elec- 
tricity if  a  connection  through  a  conductor  is  made  between  two 
points  which  are  of  different  potential.  Or  a  pressure  is  produced 
tending  to  cause  a  current  if  a  connection  were  made.  As  in  the  ruse  of 
the  water,  the  amount  of  electricity  which  will  flow  through  the  con- 
ductor in  a  certain  space  of  time  depends  upon  the  pressure  and  upon 
the  resistance.  In  the  case  of  the  water,  the  resistance  is  dependent 
upon  the  size,  length,  and  shape  of  the  pipe  through  which  it  must 
puss,  while  with  electricity  it  depends  upon  the  size,  length,  and  material 
of  the  conductor,  and  also  upon  an  inductance  which,  if  present,  may 
impede  or  augment  the  current.  This  matter  of  inductive  resistance 
is  of  the  very  greatest  importance  in  the  construction  of  coils  and 
similar  apparatus,  and  will  be  more  fully  discussed  in  another  part  of 
the  book. 

To  typify  the  usual  conditions  of  static  electricity,  the  bag  of 
water  would  have  to  be  raised  to  an  enormous  height,  and  the  column 
of  water  would  have  to  be  very  small  in  cross-section,  and  the  tube 
would  have  to  be  closed  at  the  bottom.  The  water  pressure  under 
these  conditions  becomes  perfectly  overwhelming,  and  a  powerful 
jet  of  water  would  be  thrown  through  even  u  small  opening.  If  there 
is  no  opening  at  all,  the  water  in  the  pipe  will  be  under  great  pressure, 
and  will  have  a  tendency  to  escape  through  the  smallest  kind  of  an 
opening,  or  even  to  burst  the  pipe.  A  body  charged  with  static  elec- 
tricity and  completely  insulated  is  in  the  condition  of  the  water  when 
there  is  no  opening.  If  the  voltage  becomes  too  great,  the  electricity 
breaks  through  the  resistance  of  the  air  and  a  discharge  takes  place. 
This  is  somewhat  as  if  the  water-pipe  had  burst  under  the  strain.  In 
the  case  of  water  the  pressure  is  due  to  the  height,  independent  of  the 
quantity  of  water,  the  pressure  at  the  bottom  being  fifteen  pounds  on 
every  square  inch  of  surface  for  thirty-four  feet  of  height,  whether  the 
amount  of  water  at  that  height  be  one  gallon  or  a  million  gallons. 
And  if  a  single  gallon  of  water  is  at  a  height  of  .'340  feet,  the  bursting 
pressure  at  the  bottom  will  be  150  pounds  to  the  square  inch,  exactly 
as  would  be  the  case  if  a  million  gallons  were  raised  to  the  same  height. 
The  amount  of  work  required  to  raise  the  larger  amount  to  that  height 
would,  of  course,  be  proportionately  greater,  and  so  would  the  amount 
of  work  performed  by  the  greater  quantity  in  returning  to  the  original 
level,  but  the  pressure  would  be  the  same.  A  body  charged  with  static 
electricity  is  comparable  to  a  very  small  quantity  of  water  raised  to  a 
great  height.  The  effect  of  its  discharge  is  due  almost  entirely  to  its 
pressure1,  and  hardly  at  all  to  the  quantity.  The  effect  of  a  discharge 
of  electricity  of  extremely  high  voltage  and  infinitesimal  quantity  is 
somewhat  the  same  as  the  effect  of  a  high-pressure  stream  i>!  water 
from  a  force-pump  washing  out  sand  and  gravel  from  a  hillside  by  its 
mechanic  force,  but  producing  no  appreciable  action  in  dissaving  the 
ingredients  of  the  sand  and  gravel.  The  effect  of  great  quantity,  even 
if  under  small  pressure,  is  exemplified  by  the  caverns  and  pa<sa<res 


,">2  MEDICAL    ELECTRICITY    AND    ROXTGEN    RAYS 

with  which  t  ho  solid  rock  in  the  Mammoth  Cave  of  Kentucky  has  boon 
honeycombed  by  the-  solvent  action  of  water  percolating  through  the 
ground. 

The  condition  of  the  opposite  charges  in  a  Levden  jar  or  other  con- 
denser is  illustrated  by  that  of  water  in  a  U-shaped  tube.  The  water 
on  either  side  is  maintained  at  a  hiirh  level  by  the  pressure  of  the  other 
column  of  water,  and  both  columns  will  remain  quiescent  and  at  an 
equal  level  until  either  a  large  or  a  small  opening  is  made  at  the  bottom, 
allowing  both  to  escape  from  the  tube  and  mingle  in  a  single  mass  at 
the  natural  or  neutral  level.  A  Leyden  jar  so  overcharged  as  spon- 
taneously to  discharge  is  like  such  a  U-shaped  tube,  in  which  water 
has  been  added  to  such  a  height  that  the  walls  of  the  tube  have  given 
away  and  the  water  has  escaped,  or  a  still  better  comparison  is  with 
two  equal  weights  hung  at  a  great  height  by  a  cord  fastened  over  a 
pullev:  either  one  can  be  moved  up  or  down  as  if  not  possessing  any 
weight  at  all  as  long  as  it  is  balanced  by  the  other  weight.  The}' 
remain  qiiie-cent  until  the  cord  breaks,  and  then  both  fall  to  the  ground 
with  a  crash. 

A  good  though  incomplete  analogy  with  electricity  may  be  seen 
in  compression  or  exhaustion  of  air.  Air  in  a  closed  container  at  the 
same  pressure  as  the  surrounding  atmosphere  is  like  the  electricity 
in  an  insulated  uncharged  body.  It  exerts  no  force  tending  to  break 
through  the  container:  and  if  an  opening  be  made  in  the  container 
the  condition  becomes  analogous  with  an  uncharged  and  uninsulated 
body  and  the  air  does  not  pass  through  the  opening  either  as  a  current 
or  with  a  -udden  rush. 

Pumpinir  air  into  a  closed  container  of  a  certain  size  with  rigid 
walls  and  up  to  a  certain  pressure  is  analogous  to  charging  a  body  of  a 
certain  capacity  in  microfarads  with  static  electricity  of  a  certain  volt- 
age. The  compressed  air  has  a  tendency  to  burst  the  container  or  rush 
through  any  larire  opening  made  in  it  and  immediately  reduce  the 
pre«ure  to  that  of  the  surrounding  atmosphere.  It  has  also  a  tendency 
to  e-cape  through  any  small  openings  and  so  to  gradually  equalize  the 
pressure  in-ide  and  out.  In  an  analogous  manner  a  charge  of  static 
electricity  ha-  a  tendency  to  e-cape  as  a  loud  spark  if  a  conductor  is 
brought  near  it.  or  as  a  uradual  leakage  into  the  atmosphere  from  sharp 
point-  or  in  consequence  of  imperfect  insulation. 

A  closed  cylinder  with  an  air  -pace  at  each  end.  with  a  diaphragm  in 
i  he  middle  and  a  pump  by  mean-  ot  which  air  can  be  exhausted  from 
one  hall  and  forced  into  the  other,  i-  comparable  to  the  charging  of 
the  two  pole-  of  a  static  machine  with  positive  and  negative  electricity. 
And  it  we  have  a  hole  in  the  diaphragm  with  a  pop-valve  through 
which  the  air  mav  pa--  with  a  ru-h  when  the  excess  of  pressure  be- 
coine-  -ufficieiii  to  overcome  the  resistance  of  the  valve  it  is  like  the 

-park    which    pa-se-    between    the   t  Wo   poles   of  the   Malic   machine. 

The  excess  of  positive  and  negative  charges  neutralize  each  other 
t"  -u<'h  an  extent  a-  to  prevent  the  difference  in  voltage  at  the  poles  of 
the  static  machine  from  becoming  greater  than  i-  required  to  overcome 
the  re-i~taiice  (if  i  he  -park  u'ap  between  the  discharging  rods. 

In  the  illustration  we  have  cho-en  the  air  pump  is  supposed  to  be 
in  contimiou-  operation  and  to  be  of  -ufhcient  capacity  to  constantly 
nriintain  the  de-ired  phi-  and  minu-  pre--ure-  in  the  cylinder  in  spite 
ot  the  tact  that  from  the  minu-  outlet  a  suction  apparatus  such  as  a 


STATIC'    ELECTRICITY 


vacuum  cleaner  may  he  used,  or  from  the  positive  outlet  compressed  air 
may  he  used  for  a  spray  or  atomizer.  Or  the  two  outlets  might  lead  to 
some  apparatus  through  which  it  was  desired  to  have  gaseous  contents 
of  the  cylinder  circulate,  as  in  a  machine  for  making  artificial  ice. 


a  i' 

Fig.  oS. — a.  Cylinder  with  control  diaphragm  and  air  pump  to  increase  pressure  in  one 
half  and  reduce  it  in  the  other  to  illustrate  electric  voltage,  h.  Air  pump  exhausting  at 
one  side  and  compressing  at  the  other  to  illustrate  charging  with  electricity,  c,  Safely 
valve  allowing  escape  of  air  under  excessive  pre>sure;  to  illustrate  electric  disruptive 
discharge. 

In  a  static  machine  the  positive  and  negative  poles  correspond 
to  the  plus  and  minus  outlets  and  the  spark  gap  corresponds  to  the1 
pop-valve1  in  our  compressed  air  illustration. 

Me)ne>pe>lar  applications  may  he1  made  to  the  patient  from  either 
pole  of  the1  static  mae-hine,  such  as  spark  e>r  Morton's  wave  current. 
Or,  as  an  example1  of  a  hipolar  application,  the  positive  pole  may  he1  eon- 
nee-te'el  with  an  insulated  platform  upon  whie-h  the1  patient  is  seated, 
and  the1  negative1  with  the1  metal  creiwn  for  a  static  head  hreoze;  the- 
electricity  passes  through  a  e-emtinuous  circuit.  This  ine'ludes  the 
air  spae-e  hotweem  the1  ore>wn  and  the1  patient's,  head;  and  also  the1  wood 
of  the  platform  and  chair  hetween  the 
positive1  conducting  rod  and  the  patient. 
Both  of  these  poe>r  conductors  act  te> 
mexleM'ate  the  severity  of  the1  application 
and  make  it  very  pleasant.  A  small 
ste>p-coe'k  at  each  of  the1  emtlots  fremi  the 
air  cylinele1!1  in  our  anale>gy  woulel  in  the1 
same  way  limit  the  curre-nt  of  air  from 
eMtheT  outlet  or  through  any  e'hannel 
connecte-d  with  hoth. 

To  se'ek  an  analogy  for  a  condense1!' 
we  might  have1  a  cylinder  with  two 
compartments  with  as  gtvat  a  minus 
pressure'  in  one  as  there  is  plus  in  the 
other.  The'  two  outlets  are'  separated 
only  hy  a  stop-cook,  and  opening  this 
permit-  air  to  rush  through  and  the' 
pressure1  to  hecome1  cejUalizeMl  just  as 
providing  a  conducting  path  hetween  the  two  co; 
peTinits  the  electricity  to  he1  discharuvd. 

Xo  close  analogy  exists  hy  which  we-  can  illustrate  the  force1  <>t  the1 
attraction  which  e'xi>ts  hetwe'eMi  the1  opposite1  charge's  upon  the  two 


.')4  MKDICAI,    KLKlTKICITY    AND    KOVTOK.N     KAYS 

coatings  of  a  condenser,  enabling  cadi  to  receive  a  larger  amount  of 
electricity  than  could  he  forced  into  it  l>y  a  given  pressure  or  voltage 
and  making  it  impossible  to  discharge  either  unless  the  other  is  also 
discharged.  The  capacity  of  the  condenser  is  analogous  to  the  number 
of  cubic  inches  of  -pace  in  the  air  cylinders.  The  voltage  to  which  it 
is  charged  is  analogous  to  the  number  of  pounds  pressure  to  the  square 
inch  in  the  air  cylinder.  The  quantity  of  electricity  is  not  usually 
considered  in  the  case  of  a  condenser,  but  it  would  correspond  to  the 
quantity  of  air  in  the  cylinder.  This  would  be  expressed  in  cubic 
feet  i  >f  air  at  the  ordinary  atmospheric  pressure;  and  in  the  case  of 
elect  ri  city  t  he  unit  of  quantity  is  the  coulomb,  which  is  a  quantity  capable 
ot  producing  a  certain  amount  of  electrolytic  eftect. 

The  quantity  of  air  which  a  cylinder  of  a  certain  size  will  hold  is 
directly  proportional  to  the  pressure,  and  that  is  also  the  case  with  a 
body  charged  with  electricity. 

SOURCES     OF     HIGH     ELECTROMOTIVE    FORCE    OR    STATIC    ELEC- 
TRICITY 

Natural  Sources.  /,/<//'/'«'"'/  '•-  due  to  a  very  powerful  discharge 
•  if  static  electricity.  The  charge,  is  originally  produced  by  the  evapora- 
tion "t  sea-wuter,  hi  a  thunder-cloud  thousands  of  droplets  coalesce 
into  one.  and  this,  with  a  smaller  surface;,  has  a  higher  potential  or  a 
more  concentrated  electric  charge.  This  taking  place  all  through  the 
thunder-cloud  results  in  such  an  increase  in  potential  that  a  discharge 
to  the  earth  take-  place.  A  lightning  flash  is  quite  analogous  to  the 
di-'-harge  of  a.  Leyden  jar.  The  charged  thunder-cloud  induces  an 
opposite  charge  in  the  nearest  objects  on  the  earth;  tin;  atmosphere 
forms  itie  dielectric,  and  corresponds  to  the  glass  of  the  Leyden  jar, 
while  the  thunder-cloud  and  the  oppositelv  charged  bodies  on  the 
s  irface  of  the  earth  correspond  to  the  two  metal  coatings  of  a  Levden 
jar.  The  discharge  is  like  a  spark,  sometimes  as  much  as  three  miles 
long,  and  presents  :'>(  H  ).()()()  oscillations  a  second.  Its  rending  and 
heating  effect-  are  well  known.  Its,  effect  upon  human  beings 
is  de-cribed  in  aii"ther  section  of  the  book. 

Anunnl  rifnf  ///VWVX.-.TN  all  produce  electric  charges  and  currents,  and 
in  the  c;isf  of  the  torpedo  linin  tor />i  <!<>).  electric  ell  ((/ifnin(itnx),  and  the 
electric  ti-ii  .  Jui-ns  1 1,  rlriru.- 1 ,  well-marked  shocks  can  be  given  at  will. 

I't'int  I (t>    i-  accompanied  by  electric  charges  and  currents. 

M  i  I'lui  i,  if  toj-ces  m  nature,  such  a.-  rain.  wind,  the  splitting  of  rocksj 
or  wood,  produce  electric  charges. 

The  surface  of  the  earth  normally  is  negatively  charged  as  compared 
with  the  air.  The  charge,  however,  is  very  small,  being  for  the  whole 
surface  of  the  earth  only  Jive  times  the  amount  of  electricity  carried  by 
1  LMain  of  hydrogen  in  electrolysis.  There  is  normally  a  con-tant  dis- 
charge from  the  -urface  <(f  the  earth  to  the  air. 

\nruinl  Jniiizntiini  //////,  .1/V  Over  tin  l^irtli.  -This  amount-  to  the 
production  of  about  ~2\  ion-  per  cubic  centimeter  of  air  per  second. 
The  pj-e-eiice  of  rad  inn  i  in  t  he  crii-t  of  the  earl  h  has  much  to  do  wit  h  t  he 
pheni  imeni  in. 

Ham  carries  \vith  it  to  the  earth  an  electric  charge  of  greater  or  less 
magnitude  which  i-  more  frequently  po-itive  than  negative. 

/.<;///  falling  upon  an  in-ulated  metallic  body  instantly  gives  it  an 
<  iect  ric  charge. 

Cfn/nir  /,1'nri  .  .  i .  UK'/  ittii/Htfti*  in  nature  produce  electric  charges 
a  ii'  1  current  -. 


STATIC    ELECTRICITY  O.) 

k 

Sound  will  produce  electric  charges  both  directly  and  indirect  lv. 
An  example  of  the  latter  is  seen  in  the  ordinary  telephone. 

Artificial  Sources,  -i'ricthm:  Accidental:  Walking  along  the  floor; 
combing  one's  hair.  Purposeful:  Rubbing  amber,  glass,  hard  rubber, 
sealing-wax,  fur.  wool  or  silk.  Frictional  electric  machines. 

El<  ctrostatic   Induction:      Holtx,   Toepler,    Wimshurst    machines. 

Contact  of  dixxinular  metals  (migration  of  ions). 

Heat  at  junction  of  dissimilar  metals  and  different  points  around 
the  circumference1  of  a  ring.  Heating  tourmalin. 

Electromagnetic  induction. 

Chemic  action  in  the  voltaic  cell. 

Other  Mechanic  Methods. — Splitting  a  piece  of  mica.  Pressuie 
upon  a  crystal  of  tourmalin.  Percussion.  Shaking  mercury  in  a 
vacuum  tube. 

Crystallization  of  substances  from  their  solutions. 

Solid ifications  of  molten  substances. 

Electricity  a  Universal  Attribute  of  Mailer. — All  animate  or  inanimate 
matter  is  endowed  with  electricity,  which  requires  only  some  exciting 
cause  to  make  it  manifest. 


THE   PHYSICAL   EFFECTS   OF   STATIC   ELECTRICITY 

1.  A  thoroughly  insulated  body  charged  with  either  positive  or 
negative  free  electricity — i.  c.,  unbound  by  any  inductive  influence-- 
shows  a  repulsion  of  its  component  particles,  which  is  most  perceptible 
at  its  surface.  In  electrotherapeutics,  for  instance,  the  patient's  hair 
may  stand  out  in  every  direction  from  the  head.  It  has  an  attraction 
for  bodies  oppositely  charged  or  neutral.  It  produces  or  modifies 
static  charges  in  neighboring  bodies  by  induction.  It  does  not  undergo 
any  perceptible  change  in  weight  or  physical  or  chemic  properties. 

J.  A  body  which,  like  one  coat  of  a  Ley  den  jar.  possesses  a  bound 
charge  of  electricity,  exhibits  none  of  the  properties  of  a  charged  body 
except  an  attraction  for  the  oppositely  charged  coat. 

o.  A  body  from  which  free  electricity  is  discharging  undergoes 
extremely  rapid  and  complex  molecular,  atomic,  or  subatomic  changes. 
The  discharge  escapes  either  by  convection,  conduction,  or  as  a  spark  or 
disruptive  discharge.  Particles  of  the  body  itself,  even  of  solid  metal, 
are  torn  away,  and  assist  in  carrying  the  electricity  along  the  path 
of  a  disruptive  discharge,  and  sometimes  may  be  distinguished  by  the 
characteristic  color  which  different  metals  give  to  the  spark  passing 
between  them.  The  particles  of  metal  are  vaporized  and  rendered 
incandescent,  and  may  be  recognized  by  the  spectroscope.  The 
different  appearances  of  the  discharges  from  a  positively  and  a  nega- 
tively charged  body  have  already  been  described  ( p.  281.  \\lien  a 
body  is  discharged,  the  repulsion  of  its  particles  suddenly  ceases,  and 
loose  but  still  attached  parts  of  the  body  which  have  been  spread  wide 
apart  by  mutual  repulsion  will  fall  together.  Among  inanimate 
objects  the  best  example  of  this  is  seen  in  the  gold-leaf  electroscope, 
aid  in  therapeutics  the  patient's  hair  is  suddenly  plastered  down  upon 
the  head. 

The  magnetic  effect  of  discharges  of  static  electricity  is  seen  in  the 
magnetization  of  steel  needles,  and  again  the  polarity  of  a  ship's  rompa-- • 
is  sometimes  changed  in  consequence  of  a  lightning  flash.  Xo  practical 
use  is  made  of  this  effect  of  static  elcctricitv. 


.">()  MEDICAL    KLKCTHICITY    AND    ROXTGEN    HAYS 

A  chemic  change  takes  place  in  the  charged  body  during  a  static 
discharge.  This  is  sometimes  more  readily  perceptible  in  the  air  or 
other  medium  through  which  a  discharge  takes  place.  Delicate  tests 
for  chemic  change,  however,  show  that  changes  occur  even  in  a  solid 
body  when  a  discharge  of  electricity  takes  place  from  it.  In  Fig.  40 
a  celluloid  photographic  film  wrapped  in  two  thicknesses  of  light-proof 
paper  wa<  charged  by  attaching  it  to  the  negative  pole  of  a  static 
machine.  The  numerous  small  white  spots  show  the  effect  of  the 
convectivc  discharge  upon  the  sensitized  surface,  and  the  large  white 
spot,  the  effect  of  the  disruptive  discharge  which  occurred  when  the 
other  pole  was  brought  near  to  it.  As  the  film  was  wrapped  in  closely 
fittinu  1'mht-proof  envelopes,  it  is  probable  that  the  effect  was  produced 
b  a  direct  chemic  action,  and  not  indirectly  by  the  light  of  the  sparks. 


ischarge   upon    a    photographic   film   in 


cemc  efect-  upon  the 
head  of  I'hy-ioloiric  Kf'fecH. 

Thf  hentiiiu  effect  of  the  static  discharge  upon  the  charged  body 
may  be  -hown  by  the  !u-ion  of  a  fine  wire  forming  the  discharging  point 
"t  a  powerful  bai  I  cry  of  Ley den  jars  or  in  t  real  ing  a  pat  lent  1  he  a  lit  hor 
ha-  -onietinie-  h;td  thr  point  of  one  of  his  finger-nails  scorched  by  the 
coiiveet  ive  di-charu'e.  The  fin  tier  in  tin-  case  had  been  pointed  ;it  the 
patient,  mid  acted  ;i-  ;i  concentrator,  caiismu'  the  discharge  to  take 
place  from  thai  particular  part  of  the  patient.  (  ienerally  -peaking, 
however,  the  hentuiL:  effeci  upon  the  discharging  body  it-elf  i-  very 
-liiiht.  and  -park-  may  be  applied  through  the  clothe-  without  danger 
ot  injuring  the  fabric-.  A  -ucce--ion  of  short,  powerful  sparks  applied 


STATIC    ELECTRICITY  O  ( 

at  one  spot,  of  course,  will  set  fire  to  anything,  The  heating  effects 
of  powerful  discharges  of  static  electricity  are  shown  when  a  tiny  black 
hole  is  burned  in  a  sheet  of  paper  held  between  the  two  discharging 
rods  of  it,  static,  machine,  with  Leyden  jars  connected  for  spark  effect. 
It  is  also  shown  when  a  building  is  set  on  fire  by  lightning. 

Then,  again,  when  a  wooden  clamp  with  some  metallic  parts  is  used 
for  an  .r-ray  tube,  a  spark  from  one  of  the  wires  may  set  fire  to  the  wood. 

Light  is  produced  by  static  discharges,  and  is  sometimes  seen  upon 
the  charged  bodies  as  a  glow  discharge  or  a  silent  or  convective  dis- 
charge of  a  violet  color,  and  when  this  occurs  from  a  single  point,  its 
shape  is  seen  to  vary  with  the  polarity  of  the  charged  body.  If  this 
is  negative,  the  glow  has  a  globular  appearance,  as  if  the  negative 
electricity  were  escaping  into  the  air  in  all  directions;  and  the  glow 
discharge  at  a  positively  charged  point  has  a  branching  or  brush  appear- 
ance, not  deviating  much  more  than  45  degrees  from  the  direction  in 
which  the  point  projects.  The  glow  discharge  is  not  strictly  an  effect 
upon  the  discharging  body,  but  upon  the  surrounding  air.  Solid 
particles  in  the  air  become  charged  bv  contact  with  the  charged  body 
and  are  then  repelled.  This  discharge1  is  seen  as  a  violet  light  playing 
over  the  surface  of  the  charged  body  when  a  concentrator  of  any  kind 
is  held  in  its  neighborhood,  but  still  not  near  enough  to  allow  of  a  brush 
discharge  or  eifluve  The  difference  between  the  two  varieties  is  that 
the  glow  discharge  is  silent,  continuous,  and  uniform,  and  is  visible  only 
close  to  the  surface  of  a  discharging  body,  while  a  brush  discharge  or 
eflluve  can  be  seen  in  the  dark  to  fill  up  the  space  between  the  dis- 
charging bodies  with  a  violet  light,  and  is  accompanied  by  intermittent 
sparks  or  flashes  or  by  sound.  Both  produce  a  breeze  sensation  upon 
the  human  body,  and  both  will  take  place  through  the  ordinary  clothing. 

A  static  discharge  produces  magnetic  and  electromagnetic  effect.': 
upon  the  discharging  body,  similar  to  those  of  dynamic  electricitv 
but  in  such  small  amounts  as  not  to  be  of  any  importance  in  thera- 
peutics. 

4.  The  effect  upon  the  air  from  a  discharge  of  static  electricity 
through  it  has  been  partly  indicated  in  the  previous  pages.  The  chemic 
effect  is  of  importance.  A  portion  of  the  oxygen  is  changed  into  ozone, 
and  another  small  part  of  the  oxygen  is  made  to  combine  with  some  of 
the  nitrogen  of  the  air.  The  odor  that  accompanies  the  discharge  of 
static  electricity  is  produced  by  a  combination  of  these  two  newly 
formed  compounds.  On  the  assumption  that  the  ozone  is  of  the  prin- 
cipal importance,  inhalers  have  been  made  iFig.  41)  in  which  a  glass 
globe  surrounds  the  spark  gap  and  has  two  openings — one  tor  the 
admission  of  air  and  the  other  loading  to  the  patient's  mouth  and 
nostrils.  Two  glass  vacuum  electrodes  form  a  spark-gap  free  ironi 
injurious  metallic  fumes.  The  nitric  acid  which  results  from  a  spark  dis- 
charge through  the  air  is  not  of  much  apparent  value  in  therapeutics,  but 
it  is  of  tremendous  practical  importance  in  another  way.  All  animal  and 
most  plant  life  requires  nitrogen  in  an  assimilable  form,  but  neither  of 
them  can  utilize  the  nitrogen  so  abundantly  present  in  the  atmosphere1. 
For  all  practical  purposes  the  nitrogen  is  inert,  and  simply  dilutes  the 
oxygen  which  forms  the  most  important  part  of  the  air  as  far  as  the  daily 
life  of  plants  and  animals  is  concerned.  Fven  the  nitrogen  which  i- 
al  >sorb('d  and  held  in  solution  bv  rain-wat  er  and  carried  hit  o  t  lie  earl  li  i.- 
nm  available  fur  the  nourishment  of  plants  or  animals,  \\here  water 
power  is  abundant  and  cheap  for  the  operation  of  dynamos,  the  high- 


MKDICAL    KLECTHICITY    AM)    K<  )NT(  i  KX    HAYS 


ten-ion  currents  produced  by  transformers  may  be  passed  through  an 
air-chamber.  A  multitude  of  points  produce  a  great  many  separate 
-park  paths,  and  a  spray  of  water  or  of  an  alkaline  solution  absorbs 
tlie  nitric  acid.  By  this  process  ammonia  or  nitrates  can  be  synthet- 
ically manufactured  for  fertilizers  more  cheaply  than  they  can  be 
obtained  from  natural  sources.  The  static  machine  could  be  used  in 
the  -ame  way,  but  it<  output  is  much  smaller  compared  with  the  amount 
of  work  required  to  operate  it . 

Other  Means  of  Obtaining  Nitrates  from  Atmospheric  Air.— -The 
Hnhi  r  /Vorr.vx,—  Liquid  air  obtained  by  great  pressure  at  a  very  low 
temperature  is  subjected  to  fractional  distillation.  This  separates  the 
nit rosjvu  from  the  oxygen  and  other  gases.  Hydrogen  obtained  by 
elect  roly/ing  water  is  combined  with  the  nitrogen,  and  by  this  means 
various  fertilizers  are  manufactured. 


The  cyanid  proce-<  i-  not  directly  connected  with  electricity.  It 
expose-  calcium  carbide  to  the  nitrogen  obtained  by  the  fractional  dis- 
tillation <it  IK | u id  air. 

The  ;nr  becomes  condensed  in  front  of  the  static  discharge,  and  this 
produce-;  heat  with  incandescence,  and  a  sudden  very  great  expansion 
of  the  air,  followed  bv  an  equallv  sudden  collapse  on  cooling.  The 
sound  ot  the  -park  i-  due  to  this  cause.  Heat,  light,  and  sound  are  thus 
coiic()inii;int  products  of  the  pa--age  of  static  electricity  through  the 
air  in  a  di-ruptive  di-eharge.  Th"  familiar  experiment  of  lighting  the 
ga-  by  a  -park  from  the  finucr-t  ip  i-  ;in  example  of  the  heating  effect 
of  the  static  -park  upon  the  air  through  which  it  passes.  But  the 
amount  of  heal  in"  of  the  air  by  a  -tatic  discharge  is  so  small  that  it  ha- 
no  practical  importance;  neither  i-  the  -tatic  discharge  through  the  air 
employed  tor  illumination,  but  both  the  liuht  and  sound  of  static  dis- 


STATIC    ELECTRICITY  O\) 

charges  have  important  therapeutic  effects  of  a  mental  character. 
Static  discharges  cause  a  clearing  of  the  atmosphere  by  an  effect  upon 
the  solid  or  liquid  particles  floating  in  it.  These  particles  become 
charged  with  electricity,  and  are  then  repelled  from  the  source  of 
electricit  v,  and  tend  to  collect  upon  any  non-conducting  or  poorly 
conducting  surface  in  the  neighborhood.  This  is  a  property  of  great 
practical  importance  in  .r-ray  therapy.  The  .r-ray  tube,  whether 
excited  by  a  static  machine  or  in  any  other  way,  is  a  source  of  static 
electricity,  and  causes  a  deposit  of  particles  of  dust,  and,  of  course,  of 
germs,  if  they  are  present,  upon  any  surface  near  enough  to  be  affected 
by  its  static  induction.  In  exposing  any  ulcerated  surface  the  possi- 
bility of  infection  from  this  source  must  be  considered.  If  necessary. 
it  may  be  guarded  against  by  the  interposition  of  a  thin  sheet  of  aluminum 
or  other  substance  transparent  to  the  .r-ray. 

The  condensation  of  steam  into  drops  of  water,  or  the  "pulveriza- 
tion" of  steam,  is  a  property  especially  of  statfc  electricity,  and  is  not  so 
apt  to  occur  under  the  influence  of  high-frequency  discharges.  This  is 
one  of  the  features  distinguishing  the  efHuve  or  breeze  from  these  two 
sources. 

A  dielectric  is  an  insulating  medium  which,  when  it  separates  two 
opposite  charges  of  electricity,  permits  them  to  exert  through  it  upon 
each  other  the  attraction  which  is  characteristic  of  condensers  like 
the  Leyden  jar.  Xot  all  non-conductors  are  equally  good  dielectrics, 
but  among  the  best  are  air,  glass,  shellac,  sulphur,  gutta-percha,  insulat- 
ing oils,  and  a.  vacuum.  Aside  from  the  construction  of  condensers, 
the  subject  of  dielectrics  is  of  importance  in  determining  the  material 
to  be  used  for  insulating  wires  which  are  to  carry  different  forms  of 
electricity  for  various  purposes.  For  all  cases  where  ohmic  resistance 
to  the  escape  of  the  electricity  through  the  covering  of  the  wire  is  alone 
to  be  considered,  gutta-percha  forms  an  excellent  insulating  covering. 
This  ohmic  resistance  is  a  mum,  given  to  the  resistance  to  the  passage 
of  electricity  which  corresponds  to  ordinary  friction  in  the  case  of 
mechanic  motion,  and  by  which  the  electricity  is  partly  converted  into 
heat.  It  is  a  different  matter  from  the  resistance  due  to  an  inductive 
action  in  the  circuit  itself,  which  tends  not  to  cause  electricity  to  be 
converted  into  heat,  but  to  cause  it  to  escape  like  something  of  a  dis- 
ruptive discharge  from  the  lateral  walls  of  the  conducting  path.  \Yhere 
it  comes  to  be  a  matter  of  a  condenser  action  or  of  inductive  resistance, 
as  in  the  case  of  high-frequency  currents,  and  the  currents  either  from 
a  coil  or  a  static  machine  exciting  an  .r-ray  tube,  other  insulators  not 
in  the  category  of  dielectrics  are  better.  A  thick  layer  of  gutta-percha 
will  not  prevent  the  conducting  wire  from  giving  a  shower  of  sparks 
if  it  is  touched,  or  even  if  the  hand  is  brought  near  to  it.  but  a  coating 
of  paper  or  plast  er-of-Paris  of  moderate  thickness  may  be  applied,  and 
will  permit  the  wires  leading  from  an  .r-rav  tube  to  be  handled,  or  even 
to  be  touched  together  crossed,  without  any  disagreeable  spark.  In  this 
case  there  is  a  slight  brush  discharge  which  does  not  bre;i  k  down  the 
insulation  of  the  wires. 

METHODS  OF  THERAPEUTIC  APPLICATION  OF  STATIC  ELECTRICITY 

Some  static  machines  are  provided  with  two  little  shelves,  upon  which 
the  Leyden  jars  may  rest  upon  plates,  which  form  a  metallic  connection 


00 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


with  the  external  coats  of  the  jars.  When  the  jars  are  to  be  used,  a  brass 
rod  is  adjusted  from  the  knob  connected  with  the  inner  coat  of  the 
jars  to  the  corresponding  prime  conductor  of  the  static  machine.  There 
is  an  insulated  handle  which  can  be  moved  to  various  positions,  marked 
"spark,"  "breeze."  or  "induced." 

When  this  handle  is  turned  to  "spark."  it  moves  a  brass  rod  con- 
cealed beneath  the  case  of  the  machine  to  a  position  in  which  it  touches 
both  the  metal  plates  upon  which  the  Leyden  jars  rest.  A  metallic 
connection  is  thus  made  between  their  external  coats,  just  as  is  the 
case  when  a  separate  brass  rod  is  laid  across  them  in  other  makes  of 
static  machines.  The  tremendous  detonating  sparks  obtained  in  this 
way  are  curiosities  and  might  produce  a  psychic  effect,  but  are  rarely 
actually  applied  to  a  patient. 

The  other  positions  of  the  handle — "breeze"'  and  "induced" — show 
that  the  outer  brass  rod  does  not  form  a  connection  with  the  Leyden 
jars.  Connected  with  each  brass  plate  is  a  binding  screw,  by  which 
conduct  ing  wires  may  be  placed  in  connection  with  the  outer  coat  of  the 
Leyden  jar.  These  conducting  cords  may  lead  to  sponge  or  other  elec- 
trodes for  application  to  the  patient  or  may  be  grounded. 

When  the  handle  is  in  the  position  marked  "breeze."  there  is  also 
no  connection  made  between  the  external  coats  of  the  two  Leyden  jars. 
But  in  this  case  the  Leyden  jars  may  be  dispensed  with  entirely,  for  if 
they  are  lett  in  position  they  are  not  connected  with  the  patient.  A 
-hepherd's  crook  conducts  the  electric  charge  from  one  prime  conductor 
to  the  insulated  platform  on  which  the  patient  sits,  while  a  chain  con- 
duds  the  charge  from  the  other  prime  conductor  to  the  crown,  or  to  some 
other  effluver  by  which  a  breeze  is  applied  to  some  portion  of  the  patient. 

In  other  static  machines  the  Leyden  jars  are  simply  suspended  from 
the  poles  of  the  machine  when  required. 

Static  Insulation  or  Static  Bath  or  Franklinic  Bath.-  Fig.  42  illus- 
trate- the  milde<t  wav.  This  is  known  as  static  in*ul<ition  or  xtotic  txith. 


p/aft  IH 
qrauntl 


The  insulated  platform  i-  connected  with  a  bras.-  rod.  known  as  a 
-hepherd'-  crunk,  to  the  positive  pole  of  the  static  machine.  The 
negative  pule  i-  grounded  !>v  -implv  dropping  a  chain  from  it  to  the 
flour.  Some  prefer  tn  have  a  metal  plate,  which  is  connected  by  a  wire 
tii  a  water-pipe  or  <j;a— pipe,  and  if  t  he<e  are  not  convenient,  then  the 
wire  i-  continued  out-ide  <>f  the  hou-e  and  connected  with  a  lame  metal 
plate  placed  I  or  ."j  feet  underground. 


STATK '     ELECTRICITY 


01 


Si/nopsis  of  Modcx  of  applying  static  electricity  in  medicine.1 


Conductive 


Disruptive 


Disruptive 


( 'nnvective 


I 


r  Ml 


Klectrostutir  or  franklinic  bath. 

Concentric    franklinization  J    !• 

(  Breitung  system).  t   I1 

f   I" 

I 


Static  or  franklinic  autocondtic- 
tion. 


Static  or  franklinic  autoconden- 
sation. 

f  Morton's  wave  current  or  static 
or  franklinic  undulatory  induc- 
tive i  1SS1)  (liertzian  franklini- 
zation). 

Morton's  modified  monopolar 
undulatory  current  (called  also 
Snow's  wave  current). 
Derived  franklinic  or  static 
induced  current  (Sheldon)  or 
derived  Morton  wave  current. 


ect  ropositive. 
led  roncgative 
lect  ropositive. 
Icctronegative 
ranklinic  or 

undulatory 

current, 
ranklinic      or 

undulatory 

current. 
ndulatory 

current. 
ndulatory 

current. 


{  Werber's  modification  of  Moil  on 

wave  current  ('H)O'J). 
Indirect  franklinic  or  static  dis- 
charges by  means  of  a  detona- 
tor, and  of  water  contained  in  a 
bath-tub,  in  which  the  entire 
body  is  plunged  (general  hy- 
drofranklinixation). 


Sparks  applied  by 
means  of  electrodes 
of  metal,  wood,  or 
hard  rubber;  spheric 
or  pointed. 


Aigrettes. 

Static  or  franklinic  discharges 
or  through  the  intermediary 
in  a  tub.  into  which  a  hand,  : 
hvdrot'ranklini/ation). 


{    Applied    at    a    certain 
from  the  body. 

!  Applied  directly 
regions  of  the 
by  the  clothing 

I        sage). 


distance 


on  different 
>ody  covered 
electric  ma>- 


The  sliding  rods  arc  separated  as  far  as  possible.  The  strength  of 
nil-rent  can  be  increased  by  placing  a  metal  plate  on  the  platform  and 
then  placing  the  legs  of  the  chair  on  this  metal  (Fig.  43). 

The  current  can  be  still  further  increased  by  placing  the  chair  so 
that  the  patient  can  rest  his  feet  on  the  metal  plate.  (See  Fig.  44.) 

The  only  difference  between  the  connections  for  static  insulation 

1  Slightly  modified  from  Yirgilio  Machado's  table.  Les  applications  directes 
de  I'Electricite  ;i  la  Medecine  et  a  la  C'hirurtrie.  Lisbon,  190S. 


1)2 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


and  the  Morton  wave  current  is  that  the  balls  A  and  B  are  widely  sepa- 
rated in  static  insulation,  whereas  in  the  wave  current  they  are  placed 
in  contact  to  start  with.  The  strength  of  the  current  used  for  static 
insulation  is  regulated  mainly  by  the  speed  at  which  the  machine  is 
operating.  This  method  of  application  is  generally  used  when  the 
case  is  hypersensitive  to  any  form  of  electricity.  It  has  a  general 
quieting  effect  on  the  nerves,  and  is  one  of  the  best  ways  to  begin  static 
treatment,  as  by  means  of  it  you  are  sure  to  gain  the  patient's  confi- 


'JLr.  -r.4.  — Lejzs  of  chair  on  metal  plate. 

dence.  It  does  not  produce  the  slightest  shock,  and  can  be  used  in 
the  most  sensitive  cases. 

The  static  bath  is  said  to  be  electro-positive  if  the  positive  pole  of 
the  -tatic  machine  is  connected  with  the  insulated  platform. 

The  (i/>jilic(iti<if/  nf  the  static  induced  current  from  a  machine1  of  this 
type  U  made  by  adjusting  the  handle  at  "induced."  There  is  no  con- 
nection between  the  external  coats  of  the  two  jars,  the  connecting  rod 
t>eiim  pushed  under  the  machine. 


I  lie  smallest  I.eyden  jars,  not  much  over  an  inch  in  diameter,  are 
placed  upon  the  little  shelves,  and  their  inner  coats  are  connected  with 
the  prime  conductors,  In-ulated  conducting  cords  are  fastened  to  the 
two  bindinii  posts,  and  lead  to  electrodes  applied  to  the  patient.  It  is 
nut  neee—arv.  but  customary,  for  the  patient  to  be  upon  an  insulated 
platform  mile--  there  i-  some  contra-indication,  like  the  simultaneous 
application  of  Mime  other  form  of  treatment,  such  as  vibration.  The 
machine  -hould  have  been  charged  before  the  connections  are  made  with 


STATIC    ELECTRICITY  u'ii 

the  patient,  and  is  now  set  in  operation  with  the  discharging  rods  in 
contact.  These  are  carefully  separated  to  an  extent  that  is  regulated 
by  the  sensation  of  the  patient,  but  which  will  rarely  be  found  to  be 
greater  than  £  inch,  or  3  millimeters.  This  separation  should  be  made 
gradually,  and  care  should  be  taken  not  to  allow  the  discharging  rods 
to  get  too  far  apart,  either  as  they  are  being  adjusted  or  afterward,  from 
the  motion  or  vibration  of  the  whole  machine.  An  arrangement  is 
provided  in  some  machines  whereby  a  screw-thread  on  the  discharging 
rods  is  brought  into  play  to  produce  accurately  graded  motion  of  the 
rods  as  they  are  separated,  and  to  hold  them  in  that  position.  The 
electric  currents  sent  through  the  patient  in  this  way  have  been  ex- 
plained elsewhere  (page  29). 

Fig.  45  shows  the  smallest  Ley  den  jar  connected  to  one  pole  of  the 
static  machine,  and  connected  with  the  outside  of  this  jar  is  an  ordi- 


4"). — Static  induced. 


Fip.  46.  — Static  induced,  intensified. 


nary  sponge  electrode.  The  electrode  is  placed  in  position  and  the 
current  regulated  by  slowly  separating  a  and  b.  If  a  stronger  current 
is  desired,  then  two  jars  can  be  used  as  in  Fig.  46,  regulating  in  the  same 
manner.  The  larger  the  jars  used,  the  stronger  will  be  the  current  with 
the  same  spark-gap. 

Here  again,  as  in  the  wave  current,  it  is  essential  to  have  a  perfect 
contact  between  the  electrodes  and  the  patient, 
be  used  or  two,  as  in  Fig.  47,  and  any 
electrodes  that  is  used  with  the  gal- 
vanic or  faradic  current  can  be  used 
with  the  static  induced.     As  a  rule, 
the  smallest  Leyden  jars  are  used. 


A  single  electrode  can 


,  ground 

4s.  — Morton  wave  current. 


Static   Wave    Currents. —  The   Static    Ware    Current. — This    is    also 
known  as  the  conrcct/re  discharge  current,  and  sometimes  as  the  vibratory 

C'irn  nt  or  the  Morton  in  ire  current.  In  this  method  the  metallic  plate 
of  tlie  platform  is  connected  to  the  positive  pole  of  the  static  machine, 
the  negative  pole  being  grounded,  the  sliding  rods  in  contact.  The 
patient  is  placed  on  the  platform,  having  the  feet  on  the  metallic  plate 
Kiii.  I'M.  The  strength  of  the  current  is  now  regulated  by  slowly  sepa- 


MEDIC' AL    ELECTRICITY    AND    RONTGEN    RAYS 

rating  a  and  h,  and  it  is  always  well  to  withdraw  the  negative  sliding  rod. 
If  the  patients  complain  that  they  feel  sparks  on  their  feet,  then  remove 
the  shot's,  as  this  current  should  not  be  painful;  if  it  is,  it  indicates  a 
poor  contact  between  the  metal  plate  and  the  patient. 

The  strength  of  this  current  is  regulated  by  slowly  separating  a  and 
b.  There  must  be  a  continuous  spark  between  a  and  b  when  this  current 
is  properly  used.  Instead  of  applying  the  current  through  the  feet,  as 
above  described,  any  electrode  that  is  used  with  the  galvanic  or  faradic 
current  can  be  used  in  place  of  the  metal  plate.  This  current  is  not  pain- 


l'Lr.  i'.». — X  rri>rfsriH.-  any  electrode  that  can  he  used  with  galvanic  or  faradic    current. 

fill,  and  should  not  lie  used  strong  enough  to  produce  any  unpleasant 
effect  upon  the  patient.  Its  main  therapeutic  value  is  due  to  the  fact 
that  it  stimulates  the  glandular  system  to  increased  activity.  It  also 
has  a  local  action  in  relieving  the  pain  of  sciatica. 

A  modification  (Fig.  49)  consists  in  interposing  a  large  Leyden  jar 
between  the  ground  connections  and  the  negative  pole  of  the  machine. 
The  advantage  of  this  method  will  be  appreciated  during  the  summer 
month:-:  when  the  connection  is  made1  according  to  Fig.  40,  it  may  only 
be  possible  to  obtain  a  -park  between  <i  and  b  of  2  or  3  inches,  while 


ection  as  per  Fi<i.  H)  it  may  be  found  that  it  is  possible 
to  obtain  a  spark  7  or  s  niche-  lmm\ 

I  he  -ame  method  may  be  applied  through  a  rectal  electrode1,  using 
any  electrode  that  would  be  used  with  the  galvanic  or  faradic  current. 

H<_r.  .ill  -hows  an  o/one  generator.  Fig.  .">!  shows  a  further  modi- 
fication, consisting  of  an  o/one  u-eneralor  in  which  the  spark-gap  takes 
place.  (  'onnected  with  the  o/one  generator  is  a  tube,  so  that  while  the 
patient  i<  having  the  wave  current  he  is  also  inhaling  o/one  at  the 
same  time.  This  make- a  very  successful  treatment  for  chronic  bronchial 

trouble-. 


STATIC    ELECTRICITY 


When  used  for  this  purpose,  instead  of  a  being  connected  with 
the  metal  plate  on  the  platform  the  patient  has  a  large  metal  plate  on 
the  chest.  This  may  be  in  the  form  of  tin-foil,  such  as  is  used  for  pro- 
tection against  the  .r-ray,  or  it  may  be  a  large  pad  electrode  which  has 
been  made  thoroughly  wet. 
Connected  with  the  ozone 
generator  is  a  piece  of  soft- 
rubber  tubing  having  a 
mouth-piece,  so  that  the 
patient  inhales  the  ozon- 
ized air  at  the  same  time 
the  wave  current  is  being 
passed  through  the  chest. 
This  can  be  modified  in  a 
number  of  ways.  Instead 
of  using  a  wave  current, 
the  d'Arxoni'al  high-frc-  \ 

qucnctj  current  can  be 
passed  through  the  chest 
and  the  Tesla  current  applied  to  the  ozone  generator.  In  place  of  sup- 
plying ordinary  atmospheric  air  to  the  generator,  pure  oxygen  can  be 
supplied,  in  which  case  the  patient  will  inhale  pure  ozone.  Again,  the 


Fiji.  51. — Wave  current   and  o/nn 


vacuum  electrode;  other  pole  grounded 


Wave  current  applied  by  vacu- 
um tube. 


ozonized  air  can  be  compressed  and  used  to  operate  a  nebulizing  device, 

in  which  case  various  medicated  oils  are  used. 

Fig.  52  shows  one  way  of  using  the  ordinary  vacuum  tube  with  the 

static  machine.  The  current  is  really  nothing  but  the  wave  current  ap- 
plied through  a  vacuum  electrode.  The 
strength  of  the  current  is  regulated  by 
separating  a  and  /;. 

Fig.  53  shows  another  way  of  using 
the  vacuum  electrode,  which  consists 
of  grounding  the  negative  pole  and  at- 
taching the  vacuum  electrode1  to  the 
positive  pole.  This  makes  the  current 
stronger. 

Fig.  54  shows  similar  arrangement 
with  a  Leyden  jar  which  is  suspended 
from  the  negative  pole  and  which  has 

its  external  armature  grounded.     While  the  current  passing  through  the 

vacuum  tube  causes  a  violet    color,  this  is  not   what    is  understood  as 

high-frequency  current  or  as  the  ultraviolet  ray. 

The  Electric  Connection  for  the  Static  Induced  Current  and  the  Slaf;c 

Ware  Current. — The  different  contacts  past  which  the  discharge  has  to 


OO  MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

flow  to  the  patient  should  be  perfect.  The  Leyden  jars  may  generally 
be  hunt:  upon  the  brass  rods  and  produce  a  good  enough  contact  by 
their  weight:  but  the  terminals  of  the  conduct  ing  cords  had  better  be 
secured  by  thumb-screws  instead  of  being  simply  slipped  into  the  bind- 
ing-posts. Then,  again,  the  fastening  of  the  conducting  cords  to  the 
electrodes  should  be  by  means  of  a  thumb-screw  or  pressing  the  terminal 
of  the  cord  into  a  spring  slot,  not  merely  by  twisting  it  around  some  part 
of  the  electrode.  The  two  terminals  of  the  conducting  cord,  if  they  are, 
as  usual,  separate  piece-  of  metal,  should  be  soldered  to  the  end  of  the 
wire.  Simply  twisting  the  win1  about  the  metal  terminal  will  not  do  so 
well.  At  all  these  points  of  contact  particles  of  dust  between  the 
metallic  surfaces  or  a  film  of  metallic  oxid  upon  one  or  both  surfaces  will 
make  the  contact  imperfect  and  prevent  the  flow  of  a  uniform  current. 
The  electrodes  themselves  should  be  considered.  The  ordinary  sponge 
electrode  usually  has  a  perfect  metallic  connection  from  the  conducting 
cord  to  the  metallic  surface,  over  which  the  damp  sponge  is  stretched. 
At  this  point,  however,  an  imperfection  often  develops  in  the  shape  of  a 
layer  of  verdigris  or  other  metallic  salt  upon  the  surface  covered  by  the 
sponge.  This  interferes  very  much  with  the  flow  of  the  current.  The 
result  of  an  imperfect  connection  at  any  point  is  to  increase  enormously 
the  resistance  to  the  flow  of  the  current,  and  consequently  to  make  the 
current  much  weaker.  Then  every  little  while  the  current  finds  an  un- 
obstructed  path  and  a  strong  current  flows  for  an  instant,  to  be  again 
reduced  as  the  oxid  re-forms.  The  result  is  a  series  of  disagreeable  jerks 
of  the  different  muscles  of  the  part  of  the  body  to  which  the  current  is 
applied. 

Block-tin  Electrodes. — Pure  tin  is  as  flexible  as  sheet  lead  and  does 
not  rub  off  on  the  skin  and  clothes.  Pieces  of  appropriate  size  are 
preferable  to  wet  electrodes  for  many  static  applicatkms. 

Static  Spark  and  Breeze  Applications. — With  the  same  connections 
the  patient  will  receive  a  spark  from  a  metal  ball  electrode  and  a  breeze 
or  eflluve  or  spray  from  a  pointed  one.  A  shepherd's  crook  conducts 
the  electric  charge  from  one  prime  conductor  of  the  static  machine  to  the 
insulated  platform  upon  which  the  patient  sits;  while  a  chain  conducts 
the  charge  from  the  other  terminal  to  the  crown  or  some  other  effluve  if  a 
breeze  is  to  be  applied  or  to  a  ball  electrode  for  applying  sparks;  or.  the 
other  prime  conductor  may  be  grounded,  and  indirect  sparks  may  be 
drawn  from  any  portion  of  the  patient  by  bringing  a  grounded  ball 
electrode  near  the  surface.  Another  form  of  indirect  spark  is  applied  to 
the  patient  seated  upon  an  insulated  platform,  connected  with  one  prime 
>r.  while  the  electrode  connected  with  the  other  prime  conductor 
no«  to  the  surface  of  the  patient,  but  to  a  metal  plate,  rod, 
-e  contact  wilh  the  surface.  The  effect  from  this  form  of 
)f  the  static  induced  current  or  the  wave 


'-•  .  -The  patient  is  seated  upon  the  insulated 
epherd's  crook  conducts  the  charge  from  the 

ie.  The  negative  pole  is  grounded  and 
For  the  overhead  indirect  breeze,  for 

n   the  standard  and   raised   above  the 


STATIC    ELECTRICITY 


67 


roller  electrode  is  used  and  pressed  firmly  against  the  clothing  of  the 
patient.     This  is  a  very  severe  method  of  treatment. 


y 

Fig.  55. — Indirect  method,  head  breeze. 


ITU 

Fig.  56. — Direct  method  of  applying  static  breeze  or  spark. 


Fig.  57. — Direct  head  breeze. 


Jndirccl  Spark  FAcclrodc. — Fiji.  5S  illustrates  a  method  of  directing 
the  static  >park  to  any  ])articular  part.  It  consists  simply  of  two  brass 
balls  joined  together  by  a  brass  rod  and  held  by  a  piece  of  hard  rubber 


(is 


MEDICAL    ELECTRICITY    AND    KONTCEN    KAYS 


at  an  adjustable  distance  from  tlic  metallic  part  of  the  electrode  handle. 
The  terminal  brass  hall  is  pressed  firmly  against  the  part  of  the  body  to 
which  it  is  <  le.-ired  to  direct  t  lie  spark.  A  cont  iniious  series  of  sparks  may 
lie  applied  by  connecting  the  metallic  part  of  the  electrode  handle  with 
one  pole  of  the  static  machine.  Or  separate  sparks  may  he  applied,  by 
approaching  a  ball-electrode  from  the  static  machine  and  allowing  a  spark 
to  pass  from  it  to  t  he  metallic  part  of  t  he  elect  rode  handle  and  thence  to 
the  terminal  hall  and  the  patient. 

l)irtd  ]>/'<<  :c  Aj>i>liaiti(»i.—rrh(i  connections  are  the  same  as  for  the 
direct  spark,  hut  the  electrode  is  a  pointed  one.  and  may  consist  of  metal 
or  carbon  for  the  stronger  or  of  wood  for  the  weaker  effects.  The  direct 
head  bree/.e  is  one  of  the  most  useful  of  these  applications.  The  crown 
is  at  a  considerable  distance  from  the  patient's  head  to  avoid  uncom- 
fortable prickling.  The  current  will  be  in  the  form  of  a  spark  if  a  metal 
ball  electrode  is  used.  Other  electrodes  intended  for  a  bree/e  or  spray 
are  illustrated  on  passes  44  and  45.  The  only  difference  in  this  method 
from  the  previous  one  is  that  an  electrode  is  added,  making  a  local  ap- 
plication of  the  current  instead  of  a  general  application.  The  chain  to 
which  the  electrode  is  connected  can  be  dropped  on  the  floor  or  con- 
nected to  the  gas-pipe  (Fig.  5',)). 

With  thi-  method  any  style  of  electrode  may  be  used.  In  a  general 
way  the  strength  of  the  current  is  governed  by  the  material  of  which  the 
electrodes  are  made,  wooden  electrodes  giving  milder  effects,  pointed 


met;d  electrodes  giving  a  -tronuer  effect,  and,  where  a  .-park  is  desired, 
the  large  brass  h;dl  i-  usually  used.  This  method  is  used  for  producing 
local  action  of  the  static  current,  a  strong  bree/e  being  used  in  the 
treatment  of  mild  muscular  pains,  such  a-  come  from  catching  cold. 
A  static  -park  i-  used  up  and  down  1  he  -pine  in  cases  of  loco  mot  or  ataxia 
and  for  acute  muscular  pa  in-.  In  acute  muscular  pa  in  it  will  give  almost 
in-tant  relief.  <  M  course,  the  pain-  come  back  again  in  the  course  of  a 
few  hour-,  but  can  be  ana  in  relieved  and  for  a  long  time.  It  al-o  con- 
siderably relieves  the  ataxic  pain-.  For  administering  the  bree/e, 
Codes  have  been  made  of  variou-  material-,  different  kind-  of  wood 
varying  in  the  current  according  to  their  resistance.  There  are  -ome 
hollow  electrodes  m  \\hich  have  been  placed  various  kind-  of  liquids. 

fti'lin  i 'I  SjHirl:  nml  I'm  <  :>  .  The  pat  i  cut  is  -eated  upon  1  he  in-ulated 
platform.  lo  which  the  -hepherd's  crook  conducts  the  charge  from  the 
positive  pole  of  the  static  machine.  The  negative  pole  is  grounded  and 


STATIC    ELECTRICITY 


the  electrode  is  also  grounded.  For  the  overhead  indirect  bree/e,  for 
instance,  the  crown  is  placed  in  the  standard  and  raised  at>ovc  patient's 
head  (Fig.  55). 


Fig.  00. — A  hollow  wooden  electrode  filled  with  liquid  for  long  spray. 

Figure  60  shows  the  use  of  a  hollow  wood  electrode  filled  with  water. 
This  affords  a  means  of  applying  a  spray  of  long,  thin,  painless  sparks. 


hole 


g/ass-  — 


Fig.  01. — Spray  director,  a,  can  be  moved  to  regulate  distance  between  point  and    hole 

in  glass. 

Figure  61  shows  the  author'.*  indirect  xpray  electrode  with  regulator. 
Figure  62  shows  the  method  of  application. 


rig.   Cii.'. —  Method   of  applying   >prav   director:    S.il.    i~   si>rav    director 


t    patient.        Brass   ball    is   connected    to   end   of   brass   rod    mounted   on    insul; 


[pointed  end  toward  M  pole  of  static.      Strength   of  spray  from  director  increa 


pt'inl  approaches  M  pole  ol  static.      (Original  regulating  de\  ice  by  authoi 


Production  of  <]  A  rsonral  Current*.—  l^'iiiure  (>•!  shows  the  ar 


for  securing  d'Arsonvul  high-freiiuena/  current.*  iVom  a  static 


ro 


MKDH'AL    KLFA-TH1CITY    AND    KONTCKN    RAYS 


N  x.  represent  the  sliding  rods  of  a  static  machine;  {/.  represents  a  spark- 
u-ap' mounted  in  a  box 'so  as  to  obviate  the  noise;  /,  /,  represent  two 
Teyden  jars;  tt,  represents  a  hard-rubber  tube:  r.  represents  two  binding 
posts  connected  with  the  end  of  the  coil,  which  connects  the  outside 
coatings  of  the  l.eyden  jars:  h,  represents  the  terminal  of  the  line  coil 
windmir.  which  is  inside  of  the  hard-rubber  tube  a. 

The  above  i<  the  outline  construction  of  what  is  known  as  the  I  iffard 
huinrxlntic  transformer.  It  differs  from  the  transformer  as  made  by 
Tesla  in  that  in'place  of  the  insulating  tube  a  Tesla  uses  an  insulating 


'.    (53.— Arniiiiirmi'iit    for    si-curint;    d'Arsonval     high-frequency    currents    from    static 


oil,  which  was  required  owing  to  the  extremely  heavy  currents  that  he 
used,  whereas  for  medical  work  the  oil  insulation  is  not  required. 

I)e  Kraft's  static  inducto-resonator  produces  also  high  tension  high- 
frequency  currents  and  eilluves  similar  to  those1  from  the  Oudiu 
resonator. 

THE  DOSAGE   OF   STATIC  ELECTRICITY 

When  the  patient  is  upon  the  insulated  platform,  which  is  connected 
\vith  one  pole  of  the  static  machine,  the  surface  of  the  body  in  general  is 
uniformly  charged  with  electricity.  The  density  of  the  charge  depends 
partlv  upon  the  efficiency  of  the  static  machine  and  partly  upon  the 
completeness  of  t  he  in-ulat  ion. 

The  Franklin  ha-  been  proposed  by  Benoist  as  a  practical  unit  of 
den>it  v  ot  the  -t ;i t  ic  cha ruv. 

The  C.  G.  S.  unit  of  electricity  is  a  quantity  of  electricity  which, 
concent  rat  i  •(  1  ;\\  -,\  distance  ot  1  cent  ii  net  er  from  an  equal  quantity  of  the 
same  polarity,  will  repel  it  with  a  force  equal  to  1  dyne.  The  latter  is 
about  equal  to  1  milligram.  A  coulomb  is  equal  to  i!  x  K)'1  ( '.  ( I.  S.  units, 
and  i-  a  unit  upon  which  the  amperes  and  volts  of  electric  current  are 
based,  but  i-  entirely  too  lar^e  a  unit  to  use  with  static  electricity. 
The  name  Franklin  is  given  to  t  he  small  ('.  (  i.  S.  unit ,  and  tin4  dose  of 
the  -tat  ic  b;i  t  h  i-  expressed  as  I  leum1  ID  Franklins  when  the  den  sit  y  meas- 
ured upon  eit  her  -url'ace  of  the  hand  is  equal  to  10  Franklins  per  square 
cent  imeti  T. 

Benoist  Electro-densimeter.  This  consists  of  a  delicate  elect  ro- 
scope.  which  is  cha  rued  by  ;i  n  in-ulat  ed  di^k  of  appropriate  si/e,  which  is 
applied  to  the  pat  ienl  -  hand  and  then  to  t  he  charging  rod  of  t  he  electro- 
scope. I  he  graduation  upon  t  he  instrument  should  be  such  that  tin1 
fiirure-  indicate  s,,  many  Fr.-mUin.-  per  -quare  centimeter  of  the  surface1 
tested. 


.STATIC    ELECTRICITY  /  1 

PHYSIOLOGIC  AND  THERAPEUTIC  EFFECTS   OF   STATIC  ELECTRICITY 

The  effects  of  its  application  to  the  huni;in  body  arc  muscular  con- 
traction, relaxation  of  muscular  spasm,  nerve  stimulation  or  sedation, 
and  similar  effects  upon  glandular  and  circulatory  functions  and  upon 
the  intimate  tissue  processes,  osmotic  and  others,  of  the  body,  and 
besides  electrolysis  and  cataphoresis. 

A  person  connected  with  one  pole  of  a  static  machine  does  not  remain 
charged  with  electricity  as  long  as  the  machine  is  in  operation,  unless  the 
person  is  insulated.  The  whole  current  is  unidirectional,  and  contact 
with  the  earth  prevents  its  accumulation  as  an  electric  charge.  The 
conditions  are  quite  different  from  those  prevailing  with  high-frequency 
discharges,  which  are  oscillatory  and  keep  the  patient  constantly  charged 
with  one  or  the  other  polarity. 

A  person  may  be  charged  by  induction  from  a  static  machine  only 
if  he  is  within  a  very  few  inches  of  it,  but  not  if  he  is  yards,  or  even 
miles,  away,  as  with  some  high-frequency  apparatus. 

The  production  of  heat  in  the  human  body  is  increased  during  and 
for  some  time  after  a  treatment  by  static  electricity  (Pisani  and  Mon- 
tuoro). 

chanyt'N  and  glandular  secretions  are  increased. 
e  effect x  are  obtained  from  a  static  bath  or  insulation,  and  from 
a  static  breeze  applied  exclusively  to  the  part  affected,  as  in  neuralgia. 
Static   baths   are   used,   for   instance,    in   neurasthenia,    insomnia,   and 
hysteria. 

Stimulative  effects  are  obtained  by  the  static  breeze  and  sparks,  and 
the  patients  are  generally  benefited  by  the  static  bath  in  addition. 
Cases  of  hysteric  neurasthenia  and  muscular  weakness  from  rheumatism 
or  diabetes  are  examples. 

Physiologic  Effects  of  Static  Electricity. — Adopting  Machado's 
classification  (page  410)  the  effects  of  static  electricity  may  be  grouped 
as  follows: 

(i(  n<  /'nl  stimulation,  produced  especially  by  local  or  general  disruptive 
discharges. 

Motor  stimulation,  produced  by  local  disruptive  discharges  and  the 
various  wave  currents.  It  is  not  so  characteristic  of  static  as  of  galvanic 
or  I'aradic  electricity,  and  the1  great  majority  of  static  applications  are 
not  accompanied  by  muscular  contraction.  Static  sparks  produce  con- 
traction of  the  voluntary  muscles,  and  will  do  so  even  in  some  cases  where 
other  forms  of  electricity  fail  to  act.  During  a  treatment  by  static 
elect  ricity  the  myograph  shows  t  hat  the  muscles  are  able  to  resist  fatigue 
longer  than  usual  (('aprioti,  Pisani,  and  Schnyderi. 

Static  electricity  stimulates  the  growth  of  young  animals  (Capriati's 
experiments  on  tadpoles  and  Piccinino's  on  silkworms.  The  latter 
UTOW  faster  and  better  when  exposed  to  static  electricity  than  under  the 
influence  of  high  frequency  and  autoconduction). 

Xrnsorii  stimulation,  producing  the  sensations  of  taste,  smell,  siirht. 
touch,  and  hearing.  Static  sparks  are  not.  however.  >o  effective  upon 
sensory  nerves  as  high-frequency  sparks.  The  static  breeze  applied  to 
the  head  often  flattens  the  hair  down  on  the  head  and  causes  prickling. 
which  may  be  intolerable  if  the  current  is  too  strong. 

Revulsive  ami  <lerir<ilire  <JJ<ctx  and  countcrim'tcition  produced  by 
static  sparks. 

I  <ix<><!ilfit<it/i>// .  a  secondary  effect   of  static  sparks.      Locally,  there 


72  MKDIC.VL    KI.KCTKlcrrY    AM)    KONTUKN    HAYS 

is  nallor  followed  by  redness.  Static  applications.  general  or  local,  do 
not  have  a  very  marked  effect  upon  the  circulation  in  health,  but  they 
of.  en  produce  a  favorable  effect  in  morbid  conditions  with  excited  action 
and  elevated  or  depressed  arterial  tension. 

h'<  xuln'inj  ii/nl  st!tnvlatin<i  <il>*<>rj>lion  of  ('.ruddle*  are  effects  produced 
by  static  sparks  and  the  different  wave  currents. 

K.rcito/tiitritn't  ami  </<  m  ml  or  local  tonic  (.//'<  r/*  are  produced  by  static- 
insulation  and  by  various  wave  currents  and  the  static  bree/e.  and  by 
the  current  from  a  vacuum  electrode  connected  with  one  pole  of  a 
static  machine. 

Stimulation  <>f  tin  natural  incanx  of  defense  of  the  organism  is  produced 
by  the  same  conductive  and  convective  applications. 

S«latir<  ifhcf*.  local  or  general.  are  obtained  from  a  static  bath  or 
insulation  and  from  a  static  bree/e  or  effluve  applied  directly  to  the 
affected  part.  The  wave  currents  also  have  this  property. 

The  hy  inutile  effects  of  static  electricity,  or  rather  its  effect  upon 
the  causes  of  insomnia,  are  produced  by  static  insulation  with  a  head- 
bree/e.  But  excessive  or  too  prolonged  stimulation  of  muscular  con- 
traction by  the  wave  currents  will  cause  insomnia. 

('and  ri-,ation.—  Seated  upon  an  insulated  platform  and  holding  the 
index-finger  toward  the  crown  furnishing  the  head-breeze,  a  short  spray 
of  violet  light,  hardly  more  than  a  bright  point,  may  be  seen  to  emanate 
from  the  tip  of  the  finger-nail.  The  author  has  allowed  this  to  continue 
for  a  minute  or  two  and  has  found  the  finger-nail  burnt  or  charred. 
AA'hile  he  has  never  heard  of  a  patient's  clothing  taking  fire  from  a  static 
application,  it  has  always  been  a  matter  of  wonder  to  him  that  powerful 
sparks  applied  through  delicate  fabrics  do  not  set  fire  to  them:  and 
lie  always  hold-  himself  in  readiness  to  turn  off  the  electricity  and  clap 
his  hand  over  the  ignited  part  if  such  an  event  should  take  place.  The 
same  -park-  pa—  ed  throuuh  a  sheet  of  writing-paper  produce  perfora- 
tion-. which  may  be  seen  if  the  paper  is  held  up  to  a  bright  light.  The 
inter-tice-  in  ordinary  fabrics,  however,  probably  allow  of  the  passage 
of  the  static  -park-  without  any  effect  on  the  cloth. 

Therapeutic  Indications  of  Static  Electricity.  —  A  study  of  the 
phy-ioloiiic  effects  and  the  forms  of  static  electricity  employed  to  pro- 
duce them,  will  at  once  suggest  a  wide  range  of  general  and  local  morbid 
conditions  in  which  thi-  treatment  will  be  beneficial. 

I1  or  a  coiinterirrilant  effect  from  the  static  bree/e  the  electrode  is 
negative  and  the  -en-ation  is  as  of  fine  -and  striking  the  surface.  AVith 
t  lie  positive  pole  it  would  feel  like  a  cool  bree/e,  which  is  not  so  effective. 

liisinttHifi  is  best  treated  by  static  insulation  with  the  head  bree/e. 

Static  electricity  in  nervous  diseases  is  grouped  with  electrical 
application^  in  a  -cparate  chapter  upon  electricity  in  diseases  of  the 
nervous  system. 

'I  he  following  paragraphs  are  based  upon  Machado's  classification: 

A-  a  i/i  n(  nil  xti  m  nl  ti  nt  -tat  ic  elect  ri<  -it  y  is  invaluable  in  cases  of  debil- 
|>ro-t  rat  ing  illne-s.  or  prolonged  work  and  anxiety,  as 
nd  death  o|  some  clo-e  relative.      The  author  employs 
with  :i  neu'a  1  1\  (  •  he:  id-  bree/e  for  about  fit  t  ecu  miniit  es. 
l  10  1  11   |_>  -park-  a  Ion  <:'  t  he  -pine  from  a  metal  ball.      The 


the  author 


STATIC    ELECTRICITY  I  •> 

has  known  of  several  remarkable  cures  in  which  the  psychic  element  may 
have  been  predominant . 

Static  baths  or  insulation  are  valuable  as  a  systemic  treatment  in 
pruritus  and  ec/ema. 

Static  baths  or  insulation  are  useful  in  neurasthenic  patients  \vith 
obesity. 

The  excitomotor  effect  of  the  disruptive  discharges  and  of  the  different 
\\ave  currents  may  be  an  element  in  the  benefit  from  the  latter  in  the 
treatment  of  prostatic  hypertrophy  and  chronic  inflammatory  uterine  and 
other  pelvic  conditions.  Cases  of  chronic  constipation  are  sometimes 
benefited  by  static  sparks  applied  to  the  iliac  regions. 

Muscular  contractions  as  a  separate  effect,  either  diagnostic  or  thera- 
peutic, are  more  often  secured  by  galvanic  or  faradic  currents  with  or 
without  condensers. 

The  excitomotor  effect  of  the  static  wave  current  applied  over  the 
suprapubic  region  is  useful  for  incontinence  of  urine  due  to  insufficient 
control  of  the  sphincters.  Static  sparks  and  effluves  benefit  atony  of  the 
unstriped  muscle  of  the  intestinal  wall  and  pelvic  viscera. 

The  revulsive,  derivative,  and  counter  irritant  effects  of  the  static 
sparks  are  employed  in  the  treatment  of  acute  muscular  pain,  which  is 
often  relieved  at  once,  and  on  its  recurrence  may  be  relieved  again  for 
a  longer  time.  The  lightning  pains  of  locomotor  ataxia  may  also  be 
considerably  relieved.  Chronic  painful  articular  conditions  from  gout, 
rheumatism,  and  gonorrheal  arthritis  have  been  treated  by  static 
sparks,  but  the  patients  often  complain  and  the  author  does  not  employ 
this  method  to  any  extent.  Friction  sparks  from  a  roller  electrode  or 
from  a  ball  electrode  rubbed  quickly  over  the  surface  outside  of  the  clothes 
is  an  effective1  but  very  severe  treatment  for  acute  cases  of  stiff-neck  and 
other  painful  muscular  inflammations.  Static  sparks  along  the  spine 
are  of  benefit  in  locomotor  ataxia  and  for  acute  muscular  pains  and  are 
a  splendid  general  tonic. 

This  action  explains  the  benefit  from  static  induced  currents  in  tie 
fraitntent  of  furuncles.  The  external  armature  of  one  Leyden  jar  of  the 
static  machine  is  grounded,  while  a  wire  from  the  other  leads  to  a  con- 
denser electrode1  which  is  applied  to  the  surface  of  the  boil.  This  elec- 
trode may  be  made1  extemporarily  by  stuffing  a  glass  test-tube  with  tin- 
foil. The  effect  may  be  to  prevent  suppuration,  just  as  chemical  coun- 
terirritants  will  often  do,  or,  if  pus  is  already  present,  the  application  will 
often  relieve  the  inflammatory  symptoms  and  favor  evacuation. 

The  xtat/e  breeze  is  of  service  in  ert/st})elax,  suppurating  wounds  and 
contusions,  and  ecchynwses.  The  static  breexe  is  also  an  excellent  ap- 
plication in  x/,'///  dixciisf x  of  a  neurotic  origin,  and  in  pruritus  vulva-. 
It  is  of  service  in  xynuritix.  the  patient  being  in  negative  insulation.  the- 
positive  pole  of  the  machine  grounded,  and  a  wood  electrode  or  an  ordi- 
nary whisk-broom  grounded  separately.  It  is  excellent  in  mild  mus- 
cular pains  such  as  from  catching  cold. 

JIcr/H*  zoxtrr  is  treated  by  light  and  static  resonator  effluve  or  the 
pencil  brush  discharge.1 

Lucy  ( )sborn  'U'ight  had  a  case  of  herpes  /oster  made  worse  by  light 
and  the  static  brush  discharge. 

Titus  finds  that  the  brush  discharge  for  the  acute1  .-tage  dries  up 
vesicles  and  relieves  pain." 


(4  MKDICAL    KI.KiTKICITY    AM)    KO\T(,KX    HAYS 

II<  iii/iii'hf  i<  often  relieved  hy  static  in-ulat inn  and  the  head  breeze. 

M.  I..  II.  A  riu  ild  Snow  reports  the  cure  of  sprained  ankle  in  three  treat- 
ment-: with  tin'  static  wave  current  which  acts  by  removing'  exudation 
fn  >\\i  t  he  Ivinph  spaces.1 

Overstretched  font  structures  with  exudate  in  the  plantar  fascia 
i-  treated  l.y  radiant  linht  and  heal  and  static  wave  current  there,  fol- 
lowed I  >v  -tatic  -park-  to  mu-cle  uroiip-  in  .-pa-m.- 

!•',,,•  Micra-ili'ac  xnliln.rfilinn  IVckham  and  Snow  advise  radiant  light 
and  heat  with  static  wave  currents  and  sparks  over  the  affected  joint 
and  muscles,  and.  at  (mine,  opisthotonos  exercise. 

Tin  Static  \\~<i  '  Cnm  nt  /.»•  I'^d  !<>  JJn>tlnc(.'  Muscular  Contraction 
'ui  Muscular  .!'///<*•//,/,*  ami  StijJ  Joints  (Herbert  V .  Pitcher '.—  It  is 
beneficial  for  the  adhe.-iniis  persistent  in  cases  of  tntich  foot  after  the 
pain  ha-  disappeared/1 

The  static  wave  current  and  static  sparks  are  regarded  by  Snow1 
a-  the  only  mean-  for  removing  the  induration  in  traumatic  arthritis 
and  may  prevent  the  development  of  chronic  synovitis. 

Pressure  infiltration  with  pain  and  tenderness  of  tissue  is  relieved 
by  statir  in-  >dalit  ie-. 

The  ri'-'iL^ri  and  dcricativc  effect  of  the  static  wave  currents  with  a 
moderate  excitninotor  effect  are  applied  through  a  vaginal  or  a  rectal 
electrode  in  pelvic  disorders  characterized  by  hyperemia.  Such  condi- 
tion- are  -alpiimiti-  without  suppuration,  subinvolution.  endometritis, 
dysmenorrhea.  retroversion  due  to  enlargement  of  the  uterus,  and  de- 
layed men-i  ruat  i<  m.1' 

Synovilis  i-  treated  by  the  positive  wave  current,  applied  for 
twenty  minutes  from  a  lariie  metal  or  kaolin  electrode  accurately  iit- 
t  inu'  t  he  ji  lint  !  lumphi'is  . 

Static  I'*liclricit;i  in  Circulator]!  Disora'crx. — There  is  often  an  effect 
upnii  i  he  circulation,  ;.nd  Luxenbei'ii'ei"  has  noted  a  sedative  effect  in 
patients  wiili  heart  disease  frmn  a  series  of  static  treatments,  and  has 
al-o  seen  the  ce-.-ation  <>\  mitral  murmur.-  of  spasmodic  origin  if  the 
static  bree/e  i-  applied  to  the  precordia  for  ten  minutes.  Arterial  hyper- 
t  en-ion  i-  freijueutly  reduced  l.u/enberger ).  and  static  electricity  is  also 
an  excellent  aj)  :.  tnr  arterial  hypotension. 

My  own  ob-ervat  ion-  -how  t  hat  for  conditions  <>f  low  ailei'ial  ten -ion 
and  lei-bl"  heart  the  iie-t  applical  inii<  ai'e  t  ho-e  ill  which  the  patient 
recei\  -  a  di-i'iipt  ive  di-chai'iie.  or  one  through  the  air.  -park.-,  and 
And  t<>r  hiti'h  artei'ial  ten-ion,  the  application-  in  which  the 
;  n  lil'ectly  connected  with  both  pole-  of  the  static 

machine  are  indj.-at"d.  although  not  as  effective  as  high-fVe(|Uency  cur- 
i  io  i  i-  alone  to  be  combated. 


nd    fd/nc    eliects    are    made    11-1-   of    in    rilahi'tcx. 


wondert'nllv  '.rood,  and  in  a.valii/'ia  and  uric- 


"ii.'jv.  vol.  \.\xvi.  No.  :;.  March  Mils.  p.  U7. 


l'::!i\     ;ilii|     lilidii  iloilV.    Vol.    XXXVI.    NO.     1, 


•  '    .     I.   .Io    ...    i 


\   ..    .    •    J.i.    I'.tD.'i 


STATIC     KLKCTKICITV  ,  O 

ac'demia.  Cases  of  deficient  glandular  secretion  are  benefited.  >uch  as 
hypochlorhydria  and  anachlorhydria  and  deficient  intestinal  secretion. 
The  best  method  is  to  apply  the  static  bree/e  or  brush  discharge  over  the 
abdomen  without  sparks. 

Slulic  \\'ore  for  Diabetes.— Tills  is  recommended  by  AN".  A.AN'hite.1 
but  not  in  case  of  malignant  disease  or  abscess. 

The  pat  ient  is  on  an  insulated  platform,  the  negative  pole  is  grounded, 
the  positive  being  connected  with  a  block  tin  electrode  (22  gago  thor- 
oughly wet.  4x7  inches.  Liver  and  pancreas  arc  treated  alternately. 
At  first  a  short  gap;  later  3  to  7  inches,  according  to  tolerance.  Two 
hundred  to  five  hundred  revolutions  per  minute  for  twenty  to  thirty 
minutes. 

F.  ])c  Kraft'.*  Treatment  of  Diabeff*. —  Increase  muscle  juices  and 
the  final  oxidation  of  glycogon  in  the  cells.  Kesonator  effluve  from 
static  machine  is  applied  by  bipolar  method.  Long  narrow  electrode 
over  spine  from  the  Tesla  of  static  resonator,  and  ring  effluve  all  over 
body  near  enough  to  cause  slight  muscular  twitching.  After  that  a 
metal  plate  from  the  Tesla  is  applied  to  the  abdomen  and  effluve  to 
spinal  centers  and  spinal  nerves. 

The  sinusoidal  current  applied  to  the  muscles  of  the  abdomen  and 
back  would  probably  fulfil  the  same  indications.'2 

Snow  treat es  diabetes  with  high  blood-pressure  by  autocondensa- 
tion  and  the  static  wave  current  to  the  liver  and  pancreas.  For  purely 
toxic  cases  with  gastric  derangements  and  vertigo  at  start  he  uses  t hi- 
st at  ic  wave  current  and  the  .r-ray.:! 

In  hypcrtrophic  cirrhosis  of  the  liver,  with  that  organ  extending 
far  down  into  the  abdomen,  the  static  wave  current  from  Hat  metal 
electrode  is  reported  by  Snow  to  cause  contraction  to  normal  limits  and 
restoration  of  function.'1 

Autointoxication,  also  obesity,  with  low  output  of  urinary  solids, 
are  benefited  by  static  wave  current  (Fred.  De  Kraft,  I.  c,  page  '2^'.>i. 
Cciitioti:  Don't  use  the  wave  current  with  too  long  a  spark  about  the 
face  in  arteriosclerosis:  violent  shaking  of  the  head  might  cause  ntinal 
hemorrhage.  For  diabetes  the  static  inducto-resonator  effluve  is  ap- 
plied, first,  plate  to  abdomen  and  efh'uve  to  spine;  then  plate  to  spine 
and  effluve  all  over  the  body,  moved  quickly,  causing  muscular  contiac- 
tion  and  profuse  perspiration. 

Inducto-rexonator  Actmiteil  l»i  Static  Machine.—  Designed  by  Dr. 
De  Kraft .  it  gives  I  VArsonval.  Tesla.  and  (  hid  in  currents  with  somewhat 
different  properties  from  those  obtained  from  apparatus  actuated  by 
an  induction  coil  or  a  transformer.  D'Arsonval  autocondensat  ion  from 
the  static  inducto-resonator  is  reported  by  Pitcher  to  stimulate  faulty 
metabolism,  reduce  high  blood-pressure  from  overeating  <>\i  drinking, 
to  be  useful  in  obesity,  nervousness,  insomnia,  rheumatism,  and  gout. 
Bipolar  D'Arsonva!  current  static  inducto-resonator  is  considered  by 
Pitcher  as  one  of  the  most  satisfactory  methods  of  treatment  in  chronic 
art  hrit  i-  and  synovit  is. 

Uudin    current    or   resonator  eilluve    (Pitcher!    from    static    indudo- 


it)  MKIUCAL    KLKCTKK1TY     AM)     KoNTCKN     KAYS 

resonator  is  a  condenser  discharge  of  very  high  potential.  It  produces 
muscular  contractions  with  deep  penetration,  the  rate  of  contraction 
bi-inir  varied  bv  slowing  or  increasing  the  speed  of  the  static  machine, 
and  the  intensity  or  depth  of  the  -park  gap.  A  desirable  teclmic  is 
for  the  patient  to  sit  on  a  plain  chair  upon  an  insulated  platform,  while 
a  grounded  metal  plate  from  the  negative  side  of  the  Tesla  makes  good 
contact  over  the  abdomen,  back,  or  at  the  feet.  An  insulated  cord 
from  the  top  of  the  <  Midin  solenoid  extends  to  any  suitable  electrode, 
with  an  insulated  handle.  Such  an  electrode  may  be  a  metal  ring,  and 
if  this  is  held  near  enough  to  the  back  opposite  the  metal  plate  which 
is  over  the  abdomen  good,  strong,  deep  contractions  are  produced  which 
are  beneficial  in  functional  disorders  of  the  stomach  and  colon.1  The 
metal  ring  is  moved  up  and  down  the  spine  until  there  is  decided  hy- 
peremia. This  benefits  tender  spinal  nerves  or  spinal  irritation.  The 
eliiuve  from  the  metal  ring  benefits  bronchitis,  asthma,  and  tonsillitis. 
An  active  hyperemia  of  the  neck,  chest,  and  back  is  produced.  In  many 
cases  acute  bronchitis  can  be  aborted.  Chronic  neuritis  and  muscular 
rheumatism  are  benefited.  The  inducto-resonator  eflluve  produces 
intense  hyperemia  with  local  diaphoresis  when  applied  to  old  joint 
conditions  and  vascular  diaphoresis  when  over  a  greater  area  or  entire 
body.  The  latter  makes  it  valuable  in  arterial  hypertension  due  to 
suppressed  elimination  from  almost  any  of  the  usual  causes. - 

The  bipolar  static  inducto-resonator  effluve  is  a  desirable  treatment 
for  paraly/ed  and  atrophied  muscles  from  war  injuries;  also  regular 
indirect  (not  resonaton  static  sparks  for  pressure  ulcer  and  pressure 
paralysi<  (  W.  B.  Snow1. 

For  diabetic  gangrene  William  Martin  uses  the  resonator  eflluve.-'1 

I.o\v  blood-pressure  dependent  on  toxic  conditions,  also  relaxed  con- 
dition of  veins,  especially  of  lower  extremities,  are  benefited  by  bipolar 
Malic  inducto-resonator  eflluve.' 

i!ln  ni/idtniil  urll/rilix  treated  by  static  electricity:  the  wave  current 
may  be  applied,  and  the  machine  should  be  powerful  enough  to  give  a 
-park-gap  with  an  electrode  of  b">0  or  200  square  centimeters, 
require  the  static  indirect  spark:  negative  insulation,  sparks 
-  long  drawn  from  the  patient's  body  by  a  grounded  elec- 
trode, the  poles  of  the  static  machine  far  apart.  If  the  sparks  are  too 
ndirect  bree/e  may  be  applied  or  a  wooden  ball  not  too  dry 


•at  ion    is   to   be   preferred   where   there   is  boggy  swelling 
ii     pane  111),  and  diathermy  by  high-frequency  currents 


STATIC     KLKCTKICiTV  ,  , 

Chronic  bronchiai  troubles  are  effectively  treated  by  static  wave 
curre-uts  combined  with  o/one  inhalations. 

LunilxK/o  is  tre-ate-el  by  the  aj)])licat  ion  of  a  500  ('.  P.  incandescent 
lani]>  for  fifte-e-n  minutes;  then  the  static  wave-  current  for  the  same  length 
of  time  with  electrodes  8  x  10  inche-s,  and  the-  spark-gap  increased  to 
tolerane'e-  j>e-rha])s  8  e>r  10  iiie-he-s  (Humphris). 

Sciatica.—  Finel  the-  small  af'fecte-el  a  re -a  by  a])]>lying  short  sparks 
along  the-  e-ourse  of  the-  nerve-.  A  flexible  metal  positive  electrode,  a  lit  tie 
large-r  tiian  this  area,  is  bandage-el  firmly.  The  ne-gaf  ive-  pole  is  gremnded 
and  the  spark-gap  opcncel  gradually,  because  the-  application  is  painful  at 
first.  This  is  an  application  of  the-  static  wave-  current.  Long-standing 
case's  re-<iuire-  the-  indirect  spark.  Afte-r  the-  first  three-  e>r  four  tivatme'iits 
combine1  the1  static  c-lee-tricity  with  500  C.  P.  incandescent  lamp  (Ilum- 
phris). 

(ionorrheal  Itheuma/ixm  Treated  bi/  the  Static  Wave  Current  Applied 
to  the  Proxtdie. — Titus  applies  the  vacuum  electrode  connected  with  one- 
pole-  of  a  static  machine-  to  the1  region  of  the  prostate.  This  is  on  the1 
theory  that  the-  gonococci  are  loe-ate-d  in  the  prostate,  anel  not  in  the 
joints,  and  that  they  are  weakene-el  anel  evae-uateel  with  the-  urine-  in 
consexiue-ne-e-  of  the  contractions  of  the  prostate1  caused  by  the-  electric 
applications. 

The-re  are1  cases,  however,  where  the1  gonococci  are  abundantly  pres- 
ent in  the1  pus  which  fills  the  joint,  and  where-  surgical  evacuation  anel 
disinfection  are1  requiivel. 

The1  use  of  bactericidc  applications  to  the  eleep  urethra  is  the  other 
alte-rnative-  whe-n  the  germs  have1  nett  migrateel  to  the  articulations 
and  the-  joint  troubles  are  elue  only  to  toxemic  proelucts. 

The1  application  of  the1  static  wave  current  for  facial  paralysis 
(p.  473)  anel  for  tic  eloulemreux  (p.  50b'\  anel  the  Yates  method  e)f 
tivating  ele-afness  (p.  435)  are  elese'ribed  elsewhere. 


DYNAMIC  ELECTRICITY 

DYNAMIC  electricity  may  !>c  regarded  a-  electricity  in  motion,  while 
static  electricity  is  electricity  at  rest.  Dynamic  electricity  is  known 
chiefly  by  the  effect  of  its  transmission  through  conducting  paths,  and 
static  electricity  clnelly  l»y  its  effects  as  a  stationary  charge  or  as  a 
disruptive  discharge  through  non-conducting  paths. 

NATURE  OF  DYNAMIC   ELECTRICITY 

Klectricity  of  all  kinds  is  probably  of  the  same  essential  nature. 
Dynamic  as  well  as  static  electricity  may  be  assumed  to  be  due  to  the 
application  of  forces  which  disintegrate  the  atoms  of  matter  and  liberate 
a  iireater  or  less  number  ot  ions  about  yoW  the  sixe  of  atoms.  The 
positive  ions  liberated  are  ahvays  equal  in  number  to  the  negative  ions. 
It  is  an  interesting  subject  for  speculation,  whether  perhaps  the  ions  or 
the  .-till  smaller  electrons  are  electricity  and  whether  all  matter  is  simply 
electricity  under  a  variety  of  forms.  By  the  application  of  some  force. 
such  as  chemic  affinity  in  the  case  of  a  zinc  and  a  copper  plate  dipped 
into  dilute  sulphuric  acid  and  connected  by  a  wire  outside  of  the  liquid, 
a  liberation  of  ions  is  supposed  to  take  place.  The  force  with  which 
the  positive  and  negative  ions  tend  to  pass,  through  the  different  media 
so  as  to  neutralize  each  other  is  called  the  electromotive  force,  and  is 
measured  in  volts. 

The  natural  and  artificial  sources  of  what  is  called  dynamic  elec- 
tricity trenerate  a  very  much  greater  quantity  and  at  a  very  much  lower 
pressure  than  is  the  case  with  the  form  called  static  electricity,  and  the 

production  is  usually  continuous 
and  more  or  less  uniform.  The 
distinction  is  not  at  all  an  arti- 
ficial one;  the  very  existence  of 
static  electricity  implies  a  degree 
of  insulation  sufficient  to  retain  the 
electricity  until  a  high  pressure  has 
been  produced  ;  while  with  dynamic 
electricity  the  natural  process  is 
for  it  to  have  a  conducting  path 
along  which  it  can  flow  as  fast  as 
1  it  is  generated.  The  flow  of  dy- 
namic electricity  takes  place  as 
naturally  as  t  he  flow  of  water  from 
a  higher  to  a  lower  level,  or  as  the 
movement  of  the  water  or  1  he  air 
_  when  The  hand  is  passed  through  it. 
Dvnamic  electricity  is  really  akin 
to  mechanic  motion,  while  static 
••'  to  a  tendency  to  motion  produced  by  an 


',<•  f<>rcc   which 


DYNAMIC    KLK<  TUIC1TY 


from  which  it  has  a  tendency  to  full  is  representative  of  the  force  pro- 
ducing static  electricity. 

Fig.  04  shows  another  comparison  between  electricity  arid  hydraulic 
power.  The  piston,  p,  moves  in  consequence  of  the  pressure  of  the 
water  in  the  cylinder,  and  is  supposed  to  be  connected  with  an  engine 
so  as  to  perform  work.  To  do  a  specified  amount  of  work  or  move  a 
certain  distance  against  a  certain  resistance'  requires  a  certain  water 
pressure  or  difference  in  level  between  the  water  in  the  reservoir  a  than 
in  the  reservoir  b,  and  also  implies  a  flow  of  water  through  the  tube  and 
cylinder  w  as  the  piston  moves  forward.  In  such  a  ease  the  tube  and 
cylinder  w,  tr,  and  w,  by  which  the  water  is  transmitted  from  the  upper 
to  the  lower  reservoir,  presents  a  certain  amount  of  frictional  resistance, 
and  a  certain  amount  of  work  is  expended  in  overcoming  this.  It 
makes  no  difference  how  much  water  is  contained  in  either  reservoir, 
provided  it  is  at  the  required  difference  in  level.  The  hydraulic  pressm-e 
of  a  column  of  water  so  many  feet  in  height  may  be  compared  to  the 
electric  tension  or  to  a  certain  number  of  volts  difference  in  potential. 
The  frictional  resistance  in  the  tube  and  cylinder  «•  may  be  compared 
to  the  ohmic  resistance  of  the  conducting  wire,  and  in  corroboration 
of  the  doctrine  of  the  conservation  of  energy  all  the  work  so  expended 
reappears  as  heat  or  light.  The  rate  of  now  of  the  water  through  w  is 
comparable  to  the  rate  of  flow  or  the  amperage  of  the  electric  current. 
The  work  done  in  moving  the  piston  p.  and  whatever  may  be  attached 
to  it  is  equivalent  in  our  simile  to  the 
work  done  by  the  electric  current  in 
producing  electric,  or  magnetic  in- 
duction, with  or  without  motor  ef- 
fects, and  various  chemic,  physical, 
and  physiologic  results. 

The  rate  of  flow  is  increased  by 
increasing  the  pressure  (height  of 
the  column  of  water  or  number  of 
volts  difference  in  potential);  by 
reducing  the  frictional  or  ohmic  re- 
sistance, and  by  reducing  the  resis- 
tance to  the  motion  of  the  piston  p, 
or  the  amount  of  work  to  be  performed  by  the  current.  To  make  the 
comparison  with  the  case  of  two  bodies  charged  to  a  different  potential 
and  then  connected  by  a  simple  conducting  wire  we  have  merely  to  im- 
agine that  the  piston  p  is  left  out  and  friction  of  the  tube  w  is  the  only 
resistance  to  be  overcome. 

The  diagram,  Fig.  64,  would  be  strictly  comparable  to  the  case  of 
a  constant  potential  electric  battery  if  we  should  introduce  a  pump  to 
transfer' water  from  the  lower  to  the  higher  tank,  so  as  to  maintain  the 
two  at  exactly  their  original  levels.  In  such  a  case  there  would  be  a 
uniform  circulation  of  water  through  the  apparatus,  just  as  there  is  a 
uniform  current  of  electricity  through  a  buttery  and  its  circuit. 

Two  bodies  which  are  charged  to  different  electric  potent  ials.  but 
which  are  simply  allowed  to  discharge  hv  making  an  electric  connection 
between  the  two  would  be  represented  by  I'iir.  1 55.  Here  there  is  a  dif- 
ference in  level  at  the  start,  and  the  pressure  of  the  water  causes  tl  •• 
piston  to  advance  and  the  \vater  to  reach  the  same  level  in  both  cylinders. 
Then  the  pressure  in  each  direction  becomes  equal  and  motion  ceases. 


Fin.   G5.  — Comparison  with  hydraulic 


Work  will  be  performed  as  the 


SI  I 


I  \vnamic  electricity.  including  all  kinds  of  electric  currents,  may  be 
likened  in  an1  pas<um  through  a  tube  in  consequence  ot  pressure  from 
a  pump  forcing  air  into  one  end  and  sucking  it  out  of  the  other  end 
of  the  tube.  It  i  he  tube  is  of  considerable  size  throughout  it  will 
offer  scarcely  any  resistance  to  the  passage  of  air  through  it.  and  the 
engine  working  the  pump  \vould  race  and  a  tremendous  amount  of  air 
pass  t  hrouu'h  t  he  t  ul>e  in  a  very  short  t  ime.  This  would  correspond  with 
the  effect  of  connecting  the  1  \vo  poles  of  a  battery  or  of  a  dynamo  by  a 
short,  thick  wire,  producing  a  short  circuit.  The  effect  on  a  galvanic 
batterv  is  to  cau-e  a  very  heavy  current  to  flow  and  to  quickly  exhaust 


the  battery.  In  the  case  of  a  dynamo  there  is  such  an  overwhelming 
supply  of  elect  I'icity  that  the  excessive  flow  of  electricity  in  consequence 
of  an  accidental  .-hort  circuit  will  burn  up  a  knife  blade  for  example,  and 
fuses  are  always  provided  to  cut  off  the  current  entirely  in  such  an 
event . 

If  the  tube  is  of  considerable  size  except  at  a  part  between  A  and  B, 
where  it  is  as  small  as  the  opening  in  a  gas  burner,  we  know  that  a  cer- 
tain difference  m  pre.-sure  in  A  and  B  will  cause  a  flow  of  air  through 
the  narrow  part  at  a  certain  rate,  and  that  a  greater  difference  in  pres- 


• 


"  <"iu~e  an   increa-cd   rate  of  flow.      If  the  opening  is  larger,  the 

how  i-  n real ej'  under  the  same  difference  in  pressure.      For  dia- 

have  drawn  the  simplest  form  of  air  pump,  but 

'"'-in'-;   tliai    i;    i-  a   turbine'  or  some  other  form  capable  of 

producing  a   continuous-  effect,   not    an   intermittent   one. 

I:  i  riff   portion-   of   the   tube   correspond   to  the 
•  -mall  openinu  to  the  p;trt  of  the  circuit  where 

'he  current   is  utilized.     Tin-  may  be,  for  example,  an  electric  lamp  or  a 
iralvamc  cautery  or  the  ti.-sues  of  j},,.  human  bodv.     The  difference  in 


DYNAMIC    ELECTRICITY 


81 


pressure  in  the  case  of  electricity  is  called  difference  in  potential  or  volt- 
age. The  rate  of  flow  or  the  strength,  or  more1  technically,  the  intensity 
of  the  current  is  expressed  in  amperes;  one  ampere  transport  ing  one 
coulomb  per  second.  The  resistance  is  expressed  in  ohms.  The  re- 
lation between  these  is  such  that  one  volt  will  send  a  current  of  one 
ampere  through  a  resistance  one  ohm;  and  that  'various  other  values 

V 
follow  the  formula  C  =  p-.     The  current  in  amperes  equals  the  number 

of  volts  divided  by  the  number  of  ohms  resistance. 

There  is  another  element  to  be  considered,  namely,  the  amount  of 
work  or  energy  required  corresponding  to  the  amount  of  work  measured 
in  foot  pounds  performed  by  the  pump  in  our  illustration.  Naturally 
a  greater  amount  of  work  is  required  to  maintain  an  increased  differ- 
ence of  pressure  at  the  two  sides  of  the  same  opening  and  produce  a 
corresponding  increase  in  the  flow  of  air.  In  the  case  of  electricity 
the  energy  required  is  proportional  to  the  square  of  the  voltage  if 
the  current  remains  unchanged.  The  energy  required  is  inversely 
proportional  to  the  square  of  the  resistance  if  the  currrent  remains 
unchanged.  The  energy  required  is  proportional  to  the  current  if  the 


A 


Fig.  68. — Air  pump  with  valves  in  the  piston  and  at  the  two  extremities  of  a  pipe 
through  which  it  forces  air  in  one  direction  only.  Illustrating  a  direct  electric  current, 
hut  not  nearly  so  well  as  if  a  turbine  produced  constant  pressure  in  one  direction  instead 
of  the  to-aiid-fro  motion  of  the  piston. 


voltage  remains  unchanged.  The  heating  effect  in  a  given  conduct- 
ing wire  is  simply  proportional  to  the  strength  of  the  current.  The 
most  important  fact  derived  from  these  relations  is  that  a  <riven  amount 
of  power  is  much  more  economically  transmitted  as  a  very  high  volt- 
age and  low  amperage  with  its  lesser  heating  effect  and  consequent  re- 
quirement of  less  metal  in  the  conducting  wires.  Long  distance 
transmission  of  electric  power  is  sometimes  by  a  current  of  50,000  volts. 

If  there  wow  a  single  very  long  tube  A  of  very  small  caliber  so  as 
to  offer  in  itself  considerable  resistance1  to  the  current  of  air  without  any 
narrowed  part,  this  would  correspond  to  an  electric  current  passing 
through  a  long  thin  wire  with  considerable  resistance.  If  there^were 
floating  particles  in  the  air  in  the  tube  like1  those  seen  in  a  beam  of  sun- 
light, and  if  these1  we-re1  visible1,  we  shoulel  sen1  them  moving  through 
the  tube1  at  a  evrtain  speenl  which  might,  for  instance,  be1  one  foot  a 
second. 

If  the1  tube  were  00  fret  long  it  would  take  air  particles  starting 
from  ('  ten  seconds  to  mich  the1  middle1  eif  the  tube  A.  but  _  in  a  small 
fraction  eif  a  second  after  the  pressure  begain  to  be1  applied  by  the 
pump  air  particles  at  A  would  have1  begun  to  mem1  at  the  rate  <>!  a 
foot  a  second.  The  particle's  mem1  a  fe>ot  a  second,  but  the  impulse 


S'J  MKDICAI.    KLK(  TKH1TY    AND    RONTGKN    HAYS 

which  starts  the  different  particles  in  motion  all  along  the  lino  is  vory 
much  more  rapidly  transmitted. 

A  long  chain  hanging  from  a  pulley  might  be  drawn  up  at  the  rate 
of  one  foot  a  second,  every  link  moving  at  that  rale,  but  the  lowest  link 
beginning  to  move  practically  at  the  same  moment  as  the  highest  one. 
Tlie  impulse  to  movement  may  be  transmitted  much  more  rapidly 
than  the  movement  of  the  individual  links.  With  electricity  the  elec- 
trons move  at  different  rates  of  speed  under  various  conditions,  for 
instance,  at  an  average  of  20. 000  miles  a  second  in  an  rr-ray  tube; 
but  the  transmission  of  the  impulse  is  at  a  uniform  rate  of  185, 000 
miles  a  second  under  all  conditions.  The  last  figure  is  considered  the 
velocity  of  a  cm-rent  of  electricity  and  is  the  same  as  the  velocity  of 
light. 

Water  under  a  slight  pressure  may  simply  flow  out  of  a  horizontal 
opening  an  inch  in  diameter  like  pouring  water  out  of  a  pitcher;  while 
water  under  great  pressure  from  a  vory  high  tank  or  from  a  si  earn  engine 
may  be  projected  from  such  an  opening  with  force  enough  to  knock 
a  man  off  his  foot.  This  is  analogous  to  the  difference  between  a  high 
and  low  voltage  applied  to  the  same  resistance  and  assuming  that  the 
supply  of  electricity  is  ample  in  each  case. 

SOURCES   OF  DYNAMIC  ELECTRICITY 

The  production  of  electromotive  force  occurs  in  consequence  ()f  ;i 
vor\  groat  variety  of  natural  and  artificial  causes.  Kleotric  currents 
in  useful  amounts,  are  gen  oral  oil  by  chomic  action,  by  heat,  by  the 
motion  oi  magnets  or  of  coils  of  wire  through  which  a  current  is  passing. 
And  every  vital  process  in  plains  and  animals  and  almost  every  other 
phenomenon  in  nature  or  art  are  productive  of  a  demonstrable  current. 
1  ho  mere  contact  ot  dissimilar  metals  produces  such  a  current,  and  heat 
applied  1"  the  junction  of  two  such  metals  forms  the  basis  of  a  prae- 
• :••:.  •  ilo  type  <  if  electric  bat  t orv. 

THE  VOLTAIC   OR   GALVANIC   CELL 

To  understand  the  modern  thoorv  of  dynamic  electricity  it   will  be 

useiui   to  consider  tiio  case  of  a  simple  voltaic  cell  i  Fig.  09),  consisting 

of  a  jur  p,    'tly  full  of  dilute  sulphuric  acid  in  which  dip  a  plate  of  zinc 

o  '  I   copper.      The  two  plaies  are  connected  outside  of  the  liquid 

h\    a  copper  ..   re.  which  is  a  good  conductor  of  electricity.      The  chomic 

ric   acid   upon   i  he   //me   produce-  an   electromotive 

'•;•'•'••  .<•'.•..••'•  •  rough  t  ho  liquid  from  t  he  zinc  to  1  ho  copper,  and 
i-  ci  in  tin  uod  t  hr  !gh  1  he  u  ire  out  side  o]  the  cell  irom  t  he  copper  to  the 
/inc.  Tlii-  i-  takinu  the  direction  of  the  positive  current  as  that  of  II, r 
ciiri'i  nl . 

The  Theory  of  Arrhenius   '  l>s?  .-    In   an   electrolyte.   /.  < .,  such  a 
fluid  as  the  diiuie  siiipiiuric  acid  m  the  batterv  which  we  are  consider- 
ing, the  molecule-  contain  two  kind-  ot  ions  which  are  elect  ricallv  asso- 
ciated   with    their    re-pective    electric    charge.-    before    the    generation    of 
electromotive  force.     Th'-  ion.-  move  about    irregularlv  amonu'  the 
water  molecule-,  -onieiime-  approaching  and  sometimes  receding  from 
of  the  opposite  kind.     \\  h''li  a  '  lil'fereiico  of  pot  ent  ial  i-  est  ablished 
l»et  \\-een    the    two    electrode-    by    the    chomic    action    of    the    acid    upon 


DYNAMIC    ELECTRICITY 

the  zinc,  a  directive  influence  is  exerted  upon  all  the  free  ions  in  the 
liquid  and  a  general  movement  of  ions  in  opposite  directions  takes 
place.  The  negative  ions  all  move  toward  the  zinc,  and  the  positive 
ions  all  move  toward  the  copper.  It  is  not  to  be  supposed  that  any 
individual  ion  moves  the  entire  distance  from  the  zinc  to  the  copper 
or  from  the  copper  to  the  zinc.  Any  one  ion  may  move  only  a  short 
distance  through  the  liquid  and  then  become  bound  again.  There;  is 
probably  an  interchange  of  ions  all  along  the  line,  and  the  final  result 
is  the  liberation  of  free  molecules  or  radicles  of  an  electropositive 
substance  at  one  electrode1  and  of  an  electronegative  substance  at  the 
other.  In  the  case1  of  the  voltaic  battery  which  we  are  describing  the 
electropositive  substance  which  is  liberated  is  hydrogen  gas,  and  this 
makes  its  appearance  upon  the  surface  of  the  copper  plate.  The 
electronegative  substance  is  the  acid  radicle  SO,,  and  this  enters  into 
combination  with  the  zinc,  forming  sulphate  of  zine-.  It  is  really  the 
chemic  affinity  of  the  zinc  for  the  acid  radicle  that  has  star  eel  the 
entire  process,  and  many  of  the  great  physicists  of  the  present  elay 
believe  that  chemic  affinity  is  only  a  manifestation  of  electrie-ity.  The 


chemic  change  is  noted  only  at  the  two  electrodes.  Throughout  tin- 
rest  of  the  liquid  the  changes  which  are  going  on  are  subatomic  and 
produce  uo  effect  which  can  be1  recognized  by  chemic  analysis.  Asso- 
ciated with,  and  in  consequence  of.  the  movememt  of  the  two  kinds  of 
ions  through  the  liquid  there'  is  a  current  of  electricity  through  the 
liejuid  from  the  zinc  to  the  copper,  and  this  same  current  is  continued 
outside  of  the  liquid  in  the  Avire  connecting  the  two  electrodes.  The 
current  outside  the  liquid  passes  from  the  copper  to  the  zinc,  com- 
pleting a  circuit.  If  the  two  metals  are  not  eonneeteel  by  a  Aviie  outside 
the1  liquid,  in  this  particular  case-  there1  Avill  continue  to  be-  some  action 
of  the  acid  upon  the  zinc,  and  some1  liberation  of  hydrogen  upon  the 
surtace  ot  tin-  cupper,  but  these-  will  not  be  nearly  so  vigorous  as  when 
tin1  circuit  is  completed.  Many  voltaic  ivlls  are  made-  up  of  eld  trodes 
and  an  electrolyte  between  which  no  chemic  action  takes  place  on  open 
circuit,  and  in  these,  of  course,  it  is  not  necessary  to  lift  the  elect 
t  TO  in  the  liquid  in  order  to  prevent  was!  eiful  chemic  action  Avheu  the-  bat- 
tery is  not  in  use.  This  must  be  done.  In >wever,  AVU  h  the  simple  vi  It aic 
cell  with  zinc  and  copper  elements  and  a  -ulphuric  acid  electrolvte. 
\\hile  the  circuit  is  closed  bv  the  connecting  wire  outside  the  cell 
chemic  act  i  on  goes  mi  in  the  cell,  and  an  elect  romot  ive  force  is  iz'ei  • 


84  MKDICAL    KLK(  THICITY    AND    KllXTdKN    KAYS 

and,  therefore,  the  maintenance  of  the  electromotive  force,  are  liable 
to  very  serious  reduction  by  polarization,  interference  due  to  the 
accumulation  of  hydrogen  gas  upon  the  surface  of  the  copper  plate. 

Voltaic  cells  are  made  in  which  the  action  is  uniform,  ami  in  such 
a  cell  an  electric  current  continues  to  How  at  quite  a  uniform  rate  until 
the  zinc  has  been  completely  consumed  by  the  acid  or  until  the  acid  is 
all  used  up.  The  production  of  the  electric  current  in  such  a  case  is 
analogous  to  the  evolution  of  heat  in  consequence  of  ordinary  combus- 
tion, and  the  quantity  of  electricity  produced  is  proportional  to  the 
amount  of  zinc  consumed.  The  current  is  of  greater  volume  from  a 
large  cell  with  a  large  surface  of  zinc  exposed  to  the  action  of  the  acid 
than  from  a  small  cell,  but  the  potential  or  pressure  or  voltage  is  the 
same.  The  electromotive  force,  measured  by  the  voltage,  depends 
upon  the  difference  in  potential  between  the  two  elements.  Two 
copper  plates  in  dilute  sulphuric  acid  would  not  produce  a  current, 
and  neither  would  two  zinc  plates.  Providing  a  suitable  electrolyte 
is  used,  a  zinc  and  a  copper  element  will  produce  about  1  volt,  while  a 
cell  in  which  the  positive  element  is  metallic  mercury,  and  the  negative 
element  is  zinc,  and  the  electrolyte  a  paste  consisting  of  mercurous 
sulphate  in  a  saturated  solution  of  xinc  sulphate,  produces  an  electro- 
motive force  of  about  1.4.'iG  volts.  The  electromotive  force  determines 
the  amount  of  electricity  which  a  battery  will  force  through  a  certain 
resistance.  If  the  resistance  of  the  human  body  under  certain  circum- 
stances is  2000  volts,  a  single  zinc-copper  cell  will  send  through  the  body 
only  about  .j,T1IJ()  ampere,  no  matter  how  large  the  cell  may  be  or  how 
many  amperes  it  may  be  capable  of  producing.  When  a  battery  is 
short-circuited,  or  the  copper  and  the  xinc  are  connected  outside  the 
liquid  by  a  conductor  with  practically  no  resistance,  the  amount  of 
current  that  will  How  is  proportional  to  the  amount  of  xinc  exposed  to 
the  action  of  the  acid,  and  the  larger  the  cell  the  stronger  the 
current. 

Voltaic  Cells  in  Series  and  in  Parallel. — When  two  or  more  cells 
are  connected  in  such  a  way  that  all  the  copper  plates  are  connected 
with  one  wire  and  all  the  zincs  with  another  and  the  two  wires  can  be 
brought  together  as  the  opposite  terminals  of  the  battery,  the  cells  are 
said  to  be  connected  in  parallel.  The  connection  in  series  is  made  by 
connecting  the  zinc  of  one  cell  with  the  copper  of  the  next,  making  a 
series  of  which  one  extremity  is  the  zinc  of  the  first  cell  and  the  trther 
ext  remit  v  is  the  dipper  of  the  last  cell.  The  two  battery  wires  pass 
from  1  hese  t  \vi  •  ext  ren  ,11  ies. 

A  bat  t  erv  set  U]>  in  //nrnHi  I  nr  tn  ulti/ili  acts  like  a  single  cell  with  a  large 
amount  of  xinc  surface  to  be  exposed  to  chemic  act  ion.  The  current  pro- 
duced is  of  t  he  same  larire  quant  it  y  as  if  the  zinc  surfaces  in  all  the  cells  were 
added  together  in  one  lui'ire  cell.  If  the  battery  is  made  up  of  twenty 
cell-  in  parallel,  and  all  of  the  same  size,  the  current  strength  on  short- 
circuil  \vill  be  1  went  \  t  imes  us  great  as  wit  h  a  single  cell.  'I 
however,  will  be  the  same  as  would  be  produced  by  a  single 
very  larire  number  of  cells  connected  in  parallel  will  not  se 
elertricitv  through  the  human  bodv  than  ;i  few  cells.  A 


is  about   the  same  as  with  a  single  <•< 


DYNAMIC    KLKCTIUCITY  S."> 

voltage  is  proportional  to  the  number  of  cells.  The  current  which  it 
will  send  through  the  human  body  is  proportional  1o  the  number  of 
cells,  and  with  a  very  large  number  dangerous  shocks  may  be  given. 
The  electromotive  force  of  all  the  cells  is  added  together,  while  the 
quantity  ot  electricity  generated  remains  the  same.  On  short-circuit 
the  current  will  be  no  more  with  twenty  cells  in  series  than  with  a  single 
cell,  but  when  there  is  a  certain  amount  of  resistance  in  the  circuit 
outside  of  the  cell,  the  current  which  one  cell  will  send  through  that 
resistance  is  less  than  on  short-circuit.  The  current  which  twenty  cells 
in  series  will  send  through  a  large  resistance  may  be  about  twenty  times 
what  one  cell  would  send  through  the  same  resistance.  Of  course,  the 
amount  of  current  sent  through  the  resistance  is  limited  to  the  maximum 
output  of  a  single  cell  in  the  case  of  a  series  battery. 

The  amount  of  zinc  consumed  is  the  same  in  both  cases,  and  the 
same  amount  of  power  is  generated.  The  difference  between  the  two 
types  of  buttery  is  analogous  to  that  between  two  steam-engines  con- 
suming the  same  amount  of  coal,  and  producing  the  same  amount  of 
power,  but  one  geared  to  move  a  heavy  weight  slowly,  and  the  other 
to  move  a  much  lighter  weight  at  a  correspondingly  rapid  rate.  In 
mechanic  motion  it  is  practically  true  that  it  takes  the  same  amount 
of  power  to  lift  a  body  weighing  one  pound  100  feet,  as  to  lift  100 
pounds  one  foot:  and  the  motion  of  the  two  bodies  may  be  caused  by 
suitable  transformers  to  yield  the  same  amount  of  power.  In  mechanics 
the  unit  of  power  is  the  foot-pound.  In  electricity  it  is  practically 
true  that  the  same  power  is  required  to  produce  a  current  of  one  ampere 
and  ten  volts  as  to  produce  a.  current  of  ten  amperes  and  one  volt. 
And  by  suitable  transformers  the  same  amount  of  power  may  be  obtained 
from  the  two  currents.  The  unit  of  electric  power  is  the  \nttL  or  the 
volt-ampere.  A  watt  is  produced  by  a  current  of  one  ampere  with  a 
potential  of  one  volt  or  by  a  current  of  smaller  quantity  and  a  cor- 
respondingly greater  potential.  Thus  a  current  ot  ^  ampere  and 
10  volts  produces  a  watt.  And,  on  the  other  hand,  ;,  larger  current  at 
a  correspondingly  smaller  potential  will  product1  a  watt.  In  any  case 
the  number  of  watts  is  found  by  multiplying  the  number  of  amperes  by 
tlie  number  of  volts.  The  physical  and  physiologic  effects  produced 
by  a  certain  amount  of  energy  in  the  form  of  a  current  of  high  potential 
and  low  amperage  are  radically  different  from  the  effects  of  the  same 
amount  of  energy  as  a  current  of  low  voltage  and  great  amperage.  In 
t  he  cas:1  of  t  he  volt  ale  bat  tery  and  of  t  he  generators  of  elect  ricity  known 
as  dynamos  the  -ame  amount  of  energy  may  generate1  a  current  of 
hiu;h  voltage  and  >mall  amperage  or  the  reverse,  according  lo  tin-  way 
in  which  the  different  elements  are  connected  up.  And  in  all  these 
cases  the  current  may  be  converted  from  one  type  to  the  other  without 
material  loss  of  energy'by  suitable  apparatus. 

Voltaic  cells  of  all  the  different  materials  used  as  elements  and 
electrolytes  vary  but  little  in  the  voltage  produced  by  a  >in<rle  cell. 
This  is  never  greater  than  about  three  volts.  The  amperau'e  trom  a 
simile  cell  has  no  such  limitations.  It  varies  with  the  size  of  the  ele- 
ments and  the  intetHitv  of  the  chenuc  action  between  the  electrolyte 
and  tin1  active  element.  The  strength  of  the  current,  however,  is 
regulated  by  the  resistance  it  has  to  pa<s  through,  and  this  is  made  up 
of  two  factors  --the  resistance  in  the  cell  itself  and  the  resistance  in  the 


SO  MKDICAL    KLKCTHK  ITV    AND    R(">NT<iKN    RAYS 

conduct  in»-  j)alh  outside  the  cell.  To  get  the  maximum  current  there 
should  be  the  proper  relation  between  the  electromotive  force  and  the 
internal  and  external  resistances,  and  this  is  obtained  when  the  internal 
and  external  resistances  are  equal.  The  cells  may  be  connected  in 
two  or  more  parallel  series,  securing  increased  electromotive  force  and 
an  internal  resistance  calculated  to  equal  that  of  the  external  circuit. 
One  case  in  which  a  laruv  current  is  desirable  is  for  use  as  a  cautery 
and  another  is  in  electroplating.  For  both  of  these  the  efficiency 
is  dependent  upon  the  amount  of  current,  and  in  both  cases  the  external 
resistance  is  comparatively  small.  If  a  voltaic  battery  is  used  for  these 
purposes,  it  should  consist  of  a  small  number  of  large  cells  in  series  or 
of  a  number  of  parallel  series  of  smaller  cells.  There  should  be  such  a 
number  of  these  series  that  counting  one  cell  of  each  scries  the  zinc 
surface  will  be  the  same  as  in  a  single  one  of  the  larger  cells.  If  this 
is  the  case,  the  number  of  cells  in  each  series  of  the  small  cells  may  be 
the  same  as  the  number  in  the  single  series  of  the  larger  cells.  When 
we  come  to  the  consideration  of  dynamic  electricity  produced  by  me- 
chanic means,  it  will  be  seen  that  it  is  a  very  easy  matter  to  regulate 
the  relation  between  the  quantity  and  the  potential  of  the  current  at 
its  very  source,  or  to  vary  these  relations  afterward  so  as  to  adapt  the 
current  to  various  therapeutic  requirements.  For  electric  welding, 
where  t  w<  >  pieces  of  metal  are  to  be  heati  d  red  hot,  the  ordinary  electric 
current  from  a  dynamo  is  changed  by  a  transformer  to  one  of  only 
about  five  volts,  but  of  several  hundred  amperes,  while  for  use  in  actuating 
an  .r-ray  tube  the  same  current  of  110  volts  is  transformed  into  one  of 
perhaps  100.000  volts,  and  only  a  very  few  milliainperes.  or  thousandths 
of  all  ampere.  It  is  perfectly  practicable  to  transform  the  current  from 
a  voltaic  battery  into  a  current  suitable  for  .r-ray  work.  It  is  necessary 
that  the  batterv  should  be  sufficiently  powerful,  or  should  generate  a 
sufficient  number  of  watts.  The  coil  or  whatever  kind  of  transformer  is 
used  does  not  add  one  particle  to  the  power,  but  only  changes  its  form 
just  a-  a  pulley  does  in  the  case  of  mechanic  power.  A  battery  of  from 
thirtv  to  sixty  full-sized  voltaic  cells  of  any  good  type,  such  as  the 
Lei  'lanchc  or  the  l)aiiiell.  will  give  a  sufficient  current  for  an  .r-ray  coil 
11  mechanic  interrupter,  but  will  not  produce  as  powerful  a  ray  as 
ained  from  the  110-volt  electric-light  current  generated 
i.  And  while  a  much  larger  battery  would  perhaps  do  t  he 
a~  the  electric-light  current,  it  would  cost  much  more, 
a-iu'enients  have  shown  that  the  electric  energy  obtainable 
.-:  ii  bv  the  combustion  of  a  ton  of  coal  is  six  times  that 
m  1  he  consumption  of  a  ton  of  zinc  in  voltaic  batteries, 
e,  cl  ton  o[  /inc  costs  a  great  deal  more  than  a  ton  of 
latteries  are  desirable  only  for  purposes  requiring  a 
.  verv  small  current,  and  that  only  for  short  periods 
too  frequent  intervals.  The  small  current  makes  the 
nail  as  to  be  less  than  it  would  cost  to  install  the  neces- 
rtln  use  of  a  current  from  u  dynamo.  And  the  short 
ods  of  use  keep  the  cost  of  maintenance  within 
In  the  author's  experience,  however,  the  electric- 
belter  results  for  all  kinds  of  therapeutic  work. 

depr 


DYNAMIC     KLKCTKICITY  S7 

upon  the  number  of  amperes  of  current  passing  through  the  circuit, 
and  this  can  be  regulated  in  1\vo  ways:  in  the  case  of  a  voltaic  battery 
by  using  large  colls  or  a  sufficient  number  of  parallel  cells  to  produce 
the  required  amount  of  current,  and  adding  cells  in  series  with  each  of 
the  parallel  cells,  making  a  number  of  parallel  series  producing  the 
voltage  necessary  to  send  the  necessary  amounto  f  current  through 
the  resistance  of  the  circuit:  with  the  electric-lighting  current  the 
regulation  is  accomplished  either  by  the  simple  introduction  of  the 
necessary  resistance  in  the  form  of  a  rheostat  or  by  the  use  of  a  trans- 
former. The  rheostat  adds  its  own  resistance  to  that  of  the  rest  of  the 
circuit,  and  the  number  of  amperes  which  will  pass  through  the  circuit 
is  found  by  dividing  the  number  of  volts  (110)  by  the  number  of  ohms 
resistance  in  the  entire  circuit.  A  shunt  may  also  be  used  as  a  volt 
controller  and  the  strength  of  current  regulated  in  that  way. 

Maximum  Efficiency.—  The  law  thai  the  maximum  efficiency  of 
a  source  of  electricity  is  obtained  when  the  external  resistance  is  equal 
to  the  internal  resistance  of  the  generator  is  sometimes  misleading  in 
its  practical  application.  In  the  first  place,  it  does  not  refer  merely 
to  the  intensity  or  volume  or  the  number  of  amperes  of  the  current  sent 
through  the  external  circuit.  It  refers  to  the  total  energy  sent  through 
the  external  circuit,  or,  in  other  words,  to  the  number  of  watts,  or  the 
number  of  amperes  multiplied  by  the  number  of  volts. 

In  the  case  of  several  generators,  n,  each  of  which  has  an  invariable 
electromotive  force  K.  and  internal  resistance  r,  i'ormuhe  may  be 
calculated  for  their  connection  either  in  series  or  in  parallel,  or  both 
combined  to  produce  the  greatest  number  of  watts  in  the  external 
circuit.  This  maximum  is  obtained  when — 

t  R  <]  R  n   R 

-   or  when  t  *  / 

q  r  r  \        r 

t  being  the  number  of  groups  set  up  in  series,  and  q  the  number  of  cells 
in  parallel  in  each  group. 

If  R  •-=!',  then  t  =  q  =  i/n,  or  if  the  external  resistance  is  equal  to 
the  internal  resistance  of  each  cell,  the  maximum  effect  is  obtained  by 
making  the  number  of  cells  in  each  series  equal  to  the  number  of  series, 
thus  with  o(>  dividing  them  into  n'  series  of  (>  parallel  cells  each. 

It'  R  r  then  t  q.  or  if  the  external  resistance  is  greater  than 
the  internal  resistance  of  each  cell,  the  number  of  groups  set  tip  in  series 
should  be  greater  than  the  number  of  parallel  cells  in  each  group. 

It'  r  1!  then  t  q.  or  if  the  internal  resistance  in  each  cell  is 
greater  than  the  external  resistance,  there  should  be  a  greater  number 
of  parallel  cells  in  each  group  than  there  are  of  groups  set  up  in  series. 

The  following  equations  are  examples: 

1.  In  the  case  of  a  battery  of  M(>  elements,  each  with  an  electro- 
motive force  ]•]  equal  to  l..">  volts  and  an  internal  resistance  r  equal 
to  2  ohms,  used  for  applying  a  voltaic  current  to  the  human  body 
iwith  a  resistance  K  equal  to  1000  ohms"),  the  equation  would  be  t  - 

1000 
A  ••>)  - 

possible  to  a  maximum  t  should  equal  n.  or  the  serie^  number  should 
equal  the  total  number  of  cells.  The  entire  )>(>  cells  should  be  set  up 


SS  MKDICAL    KLK<  TK1CITY    AND    KONTCKX     HAYS 

in   scries   to    send   the  greatest   number  of  watts   through   the   human 
body. 

2.    For   electrolysis   with   a   resistance   II    of   20   ohms   the   equation 
would  lie  — 


that   is.  there  should  bo  a  series  of   IS  groups  (each  group  containing 
2  parallel  cells). 

:•>.  For  cautery  with  an  external  resistance  U  equal  to  ().">  ohm  the 
equation  t<>  pro*  luce  the  niaxiniuni  number  of  watts  in  the  external 
circuit  would  lie  — 

0.5 
\™  2 

thai  is.  there  should  be  a  series  of  three  groups  (each  having  12  parallel 
cells). 

Sparking  Distance  of  Voltaic  Batteries.  —  The  sparking  distance 
obtained  from  a  voltaic  battery  increases  in  about  the  same  ratio  as 
the  voltage.  or  a  little  faster.  A  battery  of  Ue  la  Kue  chlorid  of  silver 
cell-  witii  a  voltage  of  1000  produces  a  spark  about  -.,  i  ()-  inch  long:  .">xOO 
such  cell-  .-park  across  a  space  of  -/-  inch;  1  1,000  such  cells  .spark  across 
a  -pace  :  it  -]  inch. 

Thin  v  or  forty  voltaic  cells  in  series  will  give  not  only  a  spark, 
bin  an  arc  between  the  bare  ends  of  the  two  insulated  wires  if  they  are 
fir-l  brought  together  and  then  slightly  separated.  There  is  a  certain 
amount  of  noise  produced,  and  sufficient  heat  to  vapori/e  particles  from 
the  two  metal  surface-.  If  the  individual  cells  are  small,  the  amperage 
and  the  volume  of  the  arc  \\ill  be  small;  while  if  the  cells  are  large  or 
each  member  of  the  series  is  formed  by  a  number  of  cells  in  parallel.  1  he 
av  will  <j;ive  a  powerful  li.u'ht  and  heat.  There  will  be  no  tendency  for 
the  current  to  flash  across  any  appreciable  distance;  the  sparks  are 
iced  only  after  actual  contact  ,  and  the;  thinnest  complete  layer  of 
insulating  material  is  sufficient  for  the  conducting  cords. 

Polarization  in  a.  Voltaic  Cell.      In  a  simple  xinc-coppor  ceil  with 

a   MI  per  cent,  sulphuric  acid  electrolyte  the  current   vorv  soon  becomes 

we;       on    ace     ml    of  (he  deposit    of  bubble-  of  hydrogen   gas  upon   1  he 

co]  the  copper.      The  tra-  has  very  irreat  resistance  to  1  he  passage 

of  electricit;     ;md  reduces  t  ho  curronl  strength  proportionately.    Hydro- 

gen    •_:.:-    i-  ele  ive  to  /me,  and   so  a  counter  electromotive  force 

i-    generated    which    reduces    1  he    direct     current    strength.     This    rapid 

'     e  -t  reniil  h  of  the  current    is  not    of  serious  consequence 

in  ca-e-   •-.    ere  t  he  current   is  t  o  bo  1  uriiod  on  for  onlv  shorl  periods,  as 

(or  r::.'j  .'.'_'   an   electric    iiell   or  for    caiitorv   purposes.       Ii     is    known  as 

nation,    ai  •          lelv    ceases    when    the    current     is    till'lied    "ft 

the  bubblr-    ot    lr    Irogen  escape.      One  way  of  pre\-entmg  polarixa- 

"   turnuiLr   the  current    on   and   off   frequent  Iv. 

ay  i-  by  '  •.'     iso  of  some  dopohirixer  surrounding  t  he  copper, 

••     lit  ric  or  chromic  ai  ch  has  a  strong  affinity  for  hydrogen  and 

prevents    :'-   lieiiiLT  depo   ited    upon    the  surface  ot    the  copper.       Another 

•/,  av  i  -  tn  have  t  he  copper  immer-ed  in  some  fluid,  which  will  deposit  not 

hvdro^on,    l>ut    some    Lrood    conductor,    like    metallic    copper,    upon    the 


DYNAMIC     KLKCTRICITY  89 

surface  of  the  copper.  A  solution  of  sulphate  of  copper  is  used,  in  one  of 
the  best  two-fluid  cells.  The  zinc  is  in  a  solution  of  sulphate  of  zinc 
and  the  copper  in  a  solution  of  sulphate  of  copper;  the  two  solutions 
being  in  electric  connection  through  the  porous  wall  of  the  jar  thai 
separates  them.  In  this  case;  the  substance  deposited  upon  the  cnppei 
plate  is  metallic  copper,  which  aids  rather  than  impedes  the  current. 
Xo  cell  in  which  polarization  is  not  provided  against  is  suited  for  regular 
electrotherapeutics  purposes. 

Local  Action  in  a  Voltaic  Cell. — A  piece  of  pure  zinc,  such  as  may 
be  obtained  by  distillation,  is  not  affected  by  10  per  cent,  sulphuric 
acid  if  dipped  into  it  alone  or  with  a  piece  of  copper,  unless  the  external 
connection  is  made  which  permits  the  electric,  current  to  flow.  And 
in  a  battery  in  which  the  zinc  was  absolutely  pure,  the  consumption 
of  the  zinc  would  cease  while  the  current  was  turned  off  by  opening 
the  external  circuit,  even  though  the  zinc  and  copper  still  remained  in 
the  dilute  acid,  \\ith  ordinary  commercial  zinc  this  is  far  from  being 
the  case.  The  zinc  continues  to  be  acted  upon  even  on  open  circuit. 
This  is  due  to  particles  of  impurity  in  the  zinc,  each  particle  forming  a 
voltaic  couple  with  the  neighboring  portion  of  zinc,  and  setting  up  an 
electric  current  with  an  accompanying  consumption  of  zinc  by  local 
action.  No  effect  is  produced  upon  the  copper  plate.  This  same 
local  action  also  occurs  during  the  use  of  the  battery.  It  causes  a  waste 
of  zinc  while  the  battery  is  in  operation,  and  renders  it  necessary  to 
lift  the  metals  from  the  acid  when  the  current  is  turned  off.  An 
extremely  simple  means  of  preventing  local  action  consists  in  amalga- 
mating the  surface  of  the  zinc  by  coating  it  with  metallic  mercury,  and 
quite  recently  a  manufacturer  in  Rhode  Island  has  been  able  to  melt 
zinc  and  mercury  together  in  such  a  way  as  to  make  a  complete  mixture 
of  the  two  through  the  entire  mass  of  the  zinc.  Amalgamation  removes 
the  impurities  and  leaves  the  surface  of  the  zinc  covered  with  a  liquid 
layer  of  pure  zinc  dissolved  in  mercury.  Zinc  so  prepared  is  as  free 
from  local  currents  as  if  it  were  a  plate  of  chemically  pure  zinc.  It  is 
not  affected  by  the  acid  while  the  current  is  turned  off,  and  there  is  no 
useless  consumption  of  zinc  while  the  battery  is  in  operation.  An  easy 
way  to  amalgamate  zinc  is  to  dip  it  in  hydrochloric  acid,  and  after 
drying  it,  to  rub  a  few  drops  of  mercury  over  its  surface  with  a  cloth. 
In  the  case  of  a  cell  in  which  the  zinc  is  not  amalgamated,  the  local 
action  which  takes  place  on  open  circuit,  i.  c.,  when  the  wires  are 
disconnected,  is  seen  only  at  the  surface  of  the  zinc,  where  a  consump- 
tion of  the  metal  occurs  and  there  is  a  liberation  of  hydrogen  gas.  The 
power  generated  by  the  consumption  of  the  zinc  on  open  circuit  is 
wasted  as  heat,  the  temperature  of  the  acid  rising  in  proportion  to  the 
activity  of  the  effect  upon  the  zinc. 

The  Component  Parts  of  a  Voltaic  Cell.-  The  elements  forming  a 
voltaic  couple  may  be  two  of  the  ordinary  metals,  or  a  metal  and  car- 
bon, oi1  two  liquids,  or  even  two  gases.  For  practical  purposes  the 
elements  are  always  of  the  first  two  classes.  The  electrolyte  is  almost 
ahvays  a  liquid,  and  must  conduct  electricity  and  be  decomposed  by  it. 
The  ends  of  the  elements  which  project  above  the  surface  of  the  liquid 
are  called  t  he  polr*  or  t  !<•<•(  rodis,  and  to  them  are  at  t  a  died  t  he  conduct  ing 


MKD1CAL    ELECTRICITY    AND    HoNTCKN    HAYS 

is  closed.  This  is  the  case  no  matter  what  an  affinity  the  electrolyte 
may  have  for  each  of  the  electrodes  separately.  The  electrode  which 
is  acted  upon  is  always  the  electropositive  one;  thus,  m  the  case  of  the 
zinc  and  copper  couple  in  dilute  sulphuric  acid,  only  the  zinc  is  acted 
upon,  and  eventually  the  zinc  is  entirely  consumed  and  the  acid  changes 
to  a  solution  of  sulphat<»  of  zinc.  It',  on  the  other  hand,  the  two  ele- 
ments had  been  copper  and  graphite,  the  copper  would  have  been 
the  electropositive  element  and  would  have  been  the  one  to  be  acted 
upon.  Any  metal  in  the  electromotive  series'  is  electropositive  in 
relation  to  a  metal  occurring  later  in  the  list.  The  direction  of  the 
current  through  the  electrolyte  is  from  the  electropositive  element  to 
the  other.  This  is  the  direction  of  the  positive  current.  This  is  just 
the  opposite  of  the  direction  of  the  movement  of  the  electrons,  but  it 
seems  too  late  to  change  the  time  honored  designation  of  the  ''direction 
of  the  current."  <  hitside  of  the  liquid,  however,  the  positive  current  is 
continued  from  the  copper  to  the  zinc,  so  that  the  copper  forms  the 
positive  pole  of  the  baUery  and  the  zinc  the  negative  pole.  This  is  a 
little  bit  confusinu1.  but  it  is  none  the  less  the  fact  that  the  electropositive 
element  forms  the  negative  pole  of  the  battery  as  far  as  the  external 
circuit  is  concerned. 

Wiien  the  two  pules  are  connected  outside  of  the  fluid  by  being 
touched  together  or  by  a  direct  conducting  cord  with  pra.cticu.llv  no 
resistance,  the  battery  is  said  to  be  short-circuited,  and  the  maximum 
possible  current  will  flow.  Some  batteries  give  a  very  strong  current 
on  short-circuit,  and  rapidly  become  exhausted,  while  others  do  not 
yield  much  more  than  t  heir  normal  current  and  will  run  for  a  long  time. 

The  circuit  is  closed  when  the  two  poles  are  connected  outside  the 
fluid  by  a  conducting  path  of  anv  kind  whose  resistance  may  be  very 
small,  as  in  the  case  of  a  short-circuit,  but  is  ordinarily  quite  consider- 
able. It  is  in  its  passage  through  this  external  resistance  that  the 
work  of  the  current  i-  performed,  and  that  the  power  generated  in  the 
It  is  explained  »n  p.  ]'.}~  that  this  external  resist- 
wo kinds  -ohinic  resistance  akin  to  friction,  and 
nt  of  current  bv  converting  part  of  the  power  it 
represents  into  heat;  and  inductive  resistance,  by  which  part  of  the 
current  -t rentn  h  ^eems  to  disappear  in  consequence  of  a  counter  electro- 
motive iorce  induced  bv  the  current'-  flow.  The  force  which  causes  the 
current  of  electricity  to  (low  through  the  liquid  and  through  the  con- 
ducting path  outside  the  liquid  is  called  the  chrlrowotii'r  force,  or  the 
difference  m  potential  between  the  two  pule-. 

Practical  Types  of  Single-fluid  Voltaic  Cells.  The  hichrnmntr 
fill  contains  an  electrolyte  made  bv  di  — ''Ivim:  one  pound  of  bichromate 
of  potassium  in  ten  pounds  of  wat  er  to  which  two  and  a  half  pounds  of 
concentrated  -ulp!:';ric  acid  have  previously  been  slowlv  added.  The 
elements  are  zinc  and  carbon,  both  surfaces  of  the  zinc  being  utilized  by 
placing  it  between  two  carbon-.  The  zinc  should  be  raised  irom  the 
liquid  when  the  battery  H  not  in  use.  Such  a  cell  has  an  electromotive 
.!i.~)  volts,  and  makes  an  excellent  cautery  battery. 
ill  consists  of  dilute  sulphuric  acid  as  an  electrolyte, 
a  plate  of  silver  between  two  of  zinc.  It  is  an  excellent  cell  for 

-'.h  rlrnintili  i-i    >'«.'•/'•          '/.':'..<-.   <••!.  imran.    tin,    ]'-;i'l. 
:  :  •  -.     ilvr.  Lr»M.  |>l;it  inum.  anil  irrapi.iti-. 


DYNAMIC     KLKCTHICITY  91 

nil  kinds  of  eleetrotherapetttic  purposes,  h  has  boon  extensively  used 
1'or  telegraphy  \vhoro  the  requirements  aro  much  tho  same  as  in  medical 
work,  /.  c.,  tho  oloinonts  do  not  have;  to  bo  raised  from  tho  liquid  \vhen 
not  in  use  and  tho  battery  is  always  ready  to  yield  a  lull  current  when 
the  circuit  is  closed.  To  lesson  polarization  tho  surface  of  the  silver 
is  roughened  or  coated  with  finely  divided  platinum.  Kaoh  cell  yields 
about  ().()•")  volt . 

Practical  Types  of  Double-fluid  Voltaic  Cells.  Tho  Bn-n^-n  cell 
consists  of  a  carbon  rod,  the  positive  polo,  in  strong  nitric  acid  inside  a 
porous  cell:  and  a  hollow  cylinder  of  zinc,  the  negative  pole,  in  dilute 
sulphuric  acid  in  the  large  outer  glass  cell.  The  voltage  of  each  coll 
is  about  l.Oo. 

The  (iron'  cell  is  similar  to  the  Bunsen,  but  in  it  platinum  is  used 
instead  of  carbon. 

The  I)<uti<ll  cell  is  a  standard  one.  A  copper  electrode  is  in  a  porous 
coll  filled  with  a  saturated  solution  of  sulphate  of  copper,  and  forms  the 
positive  polo.  It  is  in  the  form  of  a  hollow  copper  cylinder  with  a 
copper  cullender  at  the  top  full  of  crystals  of  sulphate  of  copper.  The 
zinc  forming  the  negative  polo  is  in  the  form  of  a  hollow  cylinder  sur- 
rounding the  porous  coll,  and  is  immersed  in  dilute  sulphuric  acid 
contained  in  the  outer  glass  jar.  The  voltage  of  a  Daniell  cell  is  about 
1.072.  "\Yhen  the  battery  is  in  operation,  metallic  copper  is  deposited 
on  the  copper  electrode  instead  of  hydrogen  gas,  and  this  aids  rather 
than  interferes  with  the  current. 

The  (/mritif  cell  uses  two  fluids,  but  depends  upon  their  difference 
in  specific  gravity  to  keep  them  separate.  The  copper  element  is  at 
the  bottom,  surrounded  by  crystals  of  sulphate  of  copper,  and  the  zinc 
element  is  at  1  he  top,  surrounded  by  a  solut  ion  of  sulphate  of  zinc,  which 
is  much  lighter  than  a  saturated  solution  of  sulphate  of  copper.  Y\  hen 
in  operation,  t he  zinc  is  acted  upon  and  removes  acid  radicles  from  tho 
solution  of  sulphate  of  zinc:  at  the  junction  between  tho  two  solutions 
the  deficiency  in  acid  radicles  in  the  zinc  sulphate  solution  is  made  up 
by  the  abstraction  of  acid  radicles  from  the  copper  sulphate  solution, 
and  at  the  surface  of  the  copper  electrode  the  deficiency  in  acid  radicles 
results  in  a  deposit  of  metallic  copper.  This  battery  is  especially  useful 
when  a  continuous  current  is  required  for  lung  periods  of  time.  It  is 
only  necessary  to  drop  in  crystals  of  sulphate  of  copper  until  the  zinc 
is  entirely  consumed,  when,  of  course,  that  also  must  be  renewed.  Tho 
two  fluids  will  mix  by  diffusion  if  the  battery  is  not  used  for  some  time. 
and  in  that  case  it  may  bo  started  by  pouring  in  a  little  dilute  sulphuric 
acid  or  zinc  sulphate  solution.  \Yhen  the  battery  is  first  start od.  it  is 
onlv  necessary  to  place  the  zinc  and  copper  elements  in  position,  fill 
tho  jar  with  water,  and  throw  in  a  handful  of  crystals  of  sulphate  of 
copper.  If  placed  on  short-circuit,  the  current  will  soon  start,  and  the 
action  of  the  acid  radicles  upon  the  xine  element  will  soon  result  in  the 
formation  of  an  upper  layer  of  zinc  sulphate  solution. 

Double-fluid  Cells  with  a  Solid  Depolarizer.-  -The  L(('!n //<•!/ '•  cdl 
uses  a  solid  depolarizer  consisting  of  a  mass  of  carbon  and  oxide  of 
manganese  tightly  packed  around  a  copper  m-  carbon  plate  inside  a 
porous  cell  which  is  sealed  by  a  layer  of  pitch  poured  over  the  top. 
The  other  element  is  a  small  zinc  rod  in  the  outer  glass  jar.  one-third 
lull  of  a  strong  solution  of  sal  ammoniac,  chlorid  of  ammonium.  This 
is  a  favorite  type  of  cell  for  electric  bells,  because  it  requires  very  little 


MKD1CA1.     KLKCTKICITY    AM)    ROXTGKX    KAYS 


care,  and  although  it  polarizes  (juickly,  it  soon  boconies  depolarized 
aiiain  by  the  combination  of  the  active  oxygen  in  the  binoxid  of 
manganese  with  the  liberated  hydrogen  gas.  It  forms  a  battery  which 
is  suitable  for  most  medical  purposes.  Jt  is  always  ready  to  yield  a 
good  current,  but  not  for  an  v  great  length  of  time.  According  to  Hous- 
ton. a  LeClanche  cell  which  has  apparently  become,  exhausted  may  be 
made  to  yield  a  good  current  again  by  washing  it  out  with  dilute  muriatic 
acid.  a'id  then  setting  it  up  again  with  a  fresh  charge  of  sal  ammoniac. 
The  electromotive  force  of  such  a  cell  is  about  1.40  volts. 

The  Edison-Lulandc  cell  has  zinc  and  copper 
elements  with  a  single  fluid  and  a  solid  depolarizer. 
The  copper  plate  is  coated  with  compressed  ox  id 
of  copper,  which  absorbs  the  hydrogen  gas  liberated 
during  the  action  of  the  cell,  and  is  to  a  corre- 
sponding extent  converted  into  metallic  copper. 
There  are  two  zinc  plates  alongside  the  copper  plate, 
and  the  electrolyte  is  a  solution  of  caustic  potash 
or  caustic  soda  in  water.  A  layer  of  paraffin  oil 
is  poured  over  the  top  of  the  liquid  to  prevent  the 
carbonic  acid  of  the  air  from  combining  with  the 
soda  or  potash  of  the  electrolyte.  The  electromo- 
tive force  of  a  cell  of  this  type  is  0.66  volt. 

The  chlorld  tif  xilrer  cell  contains  a  zinc  and 
silver  couple  in  electrolytes  of  fused  chlorid  of  silver 
and  sal  ammoniac.  Hach  cell  gives  a  voltage  of 
about  1.0.'->.  It  is  a  type  which  is  very  serviceable 
for  medical  purposes,  and  is  usually  set  up  in  a 
series  battery  so  arranged  that  from  one  to  the 
entire  number  of  cells  may  lie  used.  It  is  a  battery 
which  produces  a  small  current  with  high  electro- 
motive force.  It  is  hardly  a  practicable  type  of 
battery  for  cautery  or  any  other  purpose  requiring 
a  heavy  current.  Some  other  type  of  voltaic  cell  is 
or  a  storage  battery  of  several  cells  in  series,  or. 
the  electric-lighting  current  with  a  suitable 


better   in    tiiis   wa 
still    mure    convenient, 
tl'ansfi  inner  and  rheostat. 

Clark's  Standard  Cell.      For  measurinsr  the  electromotive  force1  of 


mparison,  and  t 

ere  arc  si  itne  ot  IK 
sufficient  to  descril 
ibe  wit  li   silver   \\ ' 
>sn  ive   mass   <  >f 
i a  1  e    and 
. 


found  in  the  current  produced  by  a. 
which  can  be  used  in  the  same  way. 
this  one  in  detail.      It   consists  of  a. 
leading  in    at    top  and   bottom   and 
merctirv    covered    bv    a    paste    of 
ihate,    and    a   negative    mass   of  pure 
ierat  ed.  and  tins  is  1  lie  reason  that  1  he  1  ube 
I'ming  t  he  elect  n  >1  vie  is  mai  le 
-i  ilnt  ii  >n  i  'f  zinc  sulphat  e, 
i    keep   it    semifluid.      Tin 
It-  electromotive  force  is 


Fleming's  Standard  Cell. 

definit  e  elect  roiiiot  i  ve   N  >rce.   a 
unki  •  ago.      It   is  m. 


U-sl 


DYNAMIC    ELECTRICITY 


is  the  zinc  electrode  in  a  solution  of  sulphate  of  zinc,  while  the  copper 
electrode  is  in  the  other  arm  in  a  solution  of  sulphate  of  copper.  Its 
potential  is  1.074  volts. 

Corrections  must  be  made  for  temperature  with  either  of  these 
standard  cells.  The  voltage  of  the  Fleming  cell,  for  instance,  diminishes 
0.08  per  cent,  for  every  degree  Centigrade  of  elevation  in  temperature. 

The  Cadmium  Cell. — A  cadmium  cell  is  another  standard  cell, 
and  has  recently  taken  the  place  of  a  Clark  cell  for  measuring  the 
electromotive  force  of  different  voltaic  cells.  The  negative  electrode 
consists  of  a  mass  of  cadmium  amalgam  fused  on  to  the  end  of  a  platinum 
wire.  It  is  in  one  vertical  arm  of  a  glass  cell  shaped  like  a  letter  H. 
The  cadmium  amalgam  is  covered  with  a  loose  mass  of  crystals  of 
sulphate  of  cadmium,  and  above  that  is  the  general  electrolyte.  This 
is  a  solution  of  sulphate  of  cadmium,  and  is  the  same  in  both  vertical 
arms  and  in  the  horizontal  junction  of  the  glass  cell.  The  positive 
electrode  is  a  plate  of  amalgamated  platinum  fused  on  to  the  end  of  a 
platinum  wire,  and  covered  by  a  paste  of  sulphate  of  mercury,  which 
fills  the  lower  part  of  the  other  vertical  arm  of  the  glass  cell.  From 
these  two  electrodes  fine  glass  tubes  lead  through  the  paraffin  wax  and 
cork  and  sealing-wax,  which  hermetically  seal  the  cell  at  the  top  of  the 
two  vertical  arms.  The  two  fine  glass  tubes  contain  metallic  mercury, 
by  means  of  which  the  conducting  rods  are  placed  in  electric  contact 
with  the  positive  and  negative  electrodes  respectively.  The  advantage 
of  this  cell  over  the  Clark  cell  is  that  it  re- 
quires practically  no  correction  for  changes  + 

in  temperature. 

of  Silver  Cell— De  La 
-Each  cell  consists  of  a 
about  6  inches  high  and  1 
inch  in  diameter,  closed  by  paraffin  wax, 
P.  W.  The  two  electrodes  are  of  zinc,  z, 
and  silver,  s.  and  the  latter  is  wrapped  with 
paraffin  paper  to  prevent  it  from  coming  into 
contact  with  the  zinc,  since  the  battery  is 
especially  designed  to  be  portable.  The  elec- 
trolyte is  one  part  chlorid  of  ammonium  and 
forty  parts  water.  The  zinc  is  the  element 
acted  upon  during  the  operation  of  the  bat- 
tery, and  when  the  battery  is  not  in  use,  the 

zinc  becomes  covered  by  a  coating  of  oxychlorid  of  zinc,  which  reduces 
the  flow  of  current  technically  by  increasing  the  internal  resistance  of 
the  cell.  This  does  not  occur  if  the  cell  is  in  frequent  use.  or  if  the  zinc 
is  taken  out  and  scraped.  Less  of  the  oxychlorid  of  zinc  is  formed 
if  the  cell  is  hermetically  sealed.  In  any  case  the  full  strength  of  the 
cell  is  elicited  by  a  few  seconds  short-circuit  in  the  case  of  a  cell  which 
has  already  been  in  use.  or  by  fifteen  minutes  short-circuit  if  the  cell  is 
entirely  new.  The  internal  resistance  of  a  cell  of  the  size  described 
here  and  with  a  zinc  rod  f\  inch  in  diameter  is  three  or  four  ohm.-". 
The  electromotive  force  is  about  !.()•'>  volts.  The  wire  connected  with 
the  ;iinc  rod  forms  the  negative  ( — )  pole  in  the  external  circuit 


The  Chlorid 
Rue's  (Fig.  71).- 
glass  vessel,  g,  g. 


Fit*   71. — Chlorid  of  silver  cell. 


94  MKDICAL    KLKCTKICITY     AM)    KONTUK.N     HAYS 


DKTAILS  OF  VAKIol'S   VOLTAIC  (T.LLS. 


copper  sul- 
phate. 

•22  to    1.      Saturate. 1      so-  O.97S 

luticm  of 
co], per  .-ul- 
phate. 

L'2  to  1.      Nit  rate  of  cop-  1.000 

per        t-atu- 
ratedi. 
_'2  to  1.      Sulphate        of  o.O'H) 

copper. 

Sulphate         of      Sulphate         of  l.i>79 

zinc      •  -at']-  copper  'sat- 

iated      solu-  urated    -olu- 

tioil    .  tioiT. 

Sulphurie  Nitric  acifi  I'latimim. 

acid  7V  to   1.  fuming'. 

Salt    water.  N  it  ric  acid. 

-p.  in'..  l.:«. 
Su]])hurif  Nitric  acid, 

acid.  _'_'  to  1.  -p.  LT-.  !.:«. 

Sulphate         of      Nit  rif  add, 

zinc.  -p    i-'!..  1..TJ. 

Dilute  Mil-      Nitric  acid.  Carbon. 

piiurie    acid. 
Sulphuric  acid Platinized    *il-  d.47 

1 :    water.  7.  ver. 

Sulphuric  acid J'latini/ed  car-          n.r>,") 

1;    water.   7.  bon. 


1.4S 
Silver.    •   Ajrf'l.      l.(«i 


'e     :  S'llpLa'eof  Lead.  (I..V) 

/.'.:•  lead. 

N      -all         '      I., rid  of  Carb    I  .  1  .0.1 

lin  c. 
I',  i       lorid    ,,f         Lead.  I. .Ml 

;  >     ite  -.il-      I  i     ite  M;|-      [Mai  num.  1  .7!i 

.        •  p'.urii   acid,. 

l':i    te     of     -  •;!-      Merc  IP  I    I.TT 


DYNAMIC     KLKCTKICITY 

•     Pl.A'I'K.                      Snl.t'TIONS     SKI'AKATKI)     I)Y     1'oitorS  I'l.ATK. 

XK<;ATI\K    I'OI.K.                                    ('1:1.1..  I'UMTIVK    I'OI.K.      YOI.I-. 

l.alande-Cha-         /inc  amain.             Can-tic       soda      ( )xid  of  copper  Iron.                           1 
peron.                                                             .-olution.                   01     "copper 

scale." 

Faure's   sepon-      Lead  plate               Dilute           sul-      Dilute           sul-  Lead          j.late       2.  to  2.2 

Jury  battery           coated    with           phuricacid.           phurie  acid,  coaled    \\ith 

minium.  minium. 

Sellon-Volck-          Lead            plate      Solution        Mil-      Solution        sul-  Lead            plate      2.15 

mar.                            primed  with           phurie     acid.           phuric   acid,  primed    with 

minium.                    sp.  ^i .,  1  . 1  HO.           sp.  Kr.,  1. 100.  minium. 

1'lante.                       Lead.                          Dilute         Mil-         Dilute            Mil-  Lead                           2  to  2.2 

phuric  acid.            phurie  acid.  isponny). 


Testing  the  Porous  Cell  in  a.  Voltaic  Cell. — The  porous  cells  used 
in  batteries  may  be  tested  in  two  ways:  by  actual  use  in  a  standard  cell 
(British  Government  test),  or  by  filling  with  distilled  water  at  a  tem- 
perature of  14°  C.,  and  seeing  if  the  leakage  in  twenty-four  hours 
amounts  to  at  least  1")  per  rent.  (Fronc'h  Government  test). 

Precautions  in  Mixing  Battery  Fluids. — When  mixing  battery 
fluids  containing  sulphuric  acid,  it  is  very  essential  to  pour  the  acid 
slowly  into  the  water.  Heat  is  produced  by  mixing  the*e  two  fluids. 
and  if  the  whole  quantity  of  acid  is  subjected  at  once  to  the  action  of 
water,  the  glass  jar  or  cell  will  certainly  crack. 

Dry  Cells.-  The  so-called  "dry  cells"  of  modern  commerce  differ 
in  no  essential  respect  from  an  ordinary  zinc-carbon  voltaic  cell.  The 
amount  of  fluid,  however,  is  small,  and  it  is  held  in  some  absorbent 
material  like  sawdust,  or  it  may  be  in  a  jelly-like  mass.  The  outside 
of  such  a  cell  is  generally  a  zinc  container  which  forms  one  electrode, 
while  the  other  electrode  is  a  rectangular  carbon  rod  around  which 
the  electrolyte  is  pa  ked.  The  can  is  sealed  by  a  layer  of  asphaltum 
to  prevent  evaporation  of  the  electrolyte. 

Hatteries  of  dry  cells  set  up  in  series  are  very  convenient  for  actuat- 
ing a  faradic  coil  or  for  1  lie  lighter  forms  of  electrolysis  and  galvanism. 
They  are  not  verv  well  adapted  to  cautery  purposes  or  to  ./'-ray  work. 

Fi'rv's  recent  I  v  patented  dry  eel!  is  claimed  to  give  quite  a  constant 
current.  The  positive  pole  i<  formed  by  the  zinc  can  containing  the 
01 1  KM'  parts  of  1  he  bat  1  cry.  There  is  a  bottom  layer  of  porous  substance, 
such  as  infusorial  earth,  cotton,  or  powdered  pumice-stone,  moistened 
with  such  a  liquid  as  a-  solution  of  sodium  sulphate.  The  zinc  is  lined 
with  blotting-paper  or  felt.  The  carbon  positive  electrode  is  placed 
in  the  upper  part  of  1  he  jar,  and  surrounded  by  a  depolarizing  substance, 
such  as  a  mixture  ot  graphite  and  mercury  sulphate  made  into  a  paste 
with  sodium  sulphate  solution. 

Expense  of  Electric  Power  from  Voltaic  Cells.  The  amount  of 
zinc  consumed  in  a  voltaic  batter  has  been  calculated  to  be  for  one 


Thi<  is  very  much  more  expensive  than  burning  coal.   oil.   or  gas  to  run 
a  dynamo  and   produce  the  same  amount  of  electric  energy 
siderable   power    is   required    for   anv    lenti'li    of   time.      1  nder    certain 
conditions,    in    electrothera]>y.    hoAvever,    the    voltaic    battery 
economic     when   only  a  small   amount    of  power  H  required  .-  ' 


VM)  MK1HCAL    KLKCTRICITY    AND    KO.VHiEX    RAYS 

periods,  and  only  for  a  short  time,  and  when  a  portable  apparatus  is 
required.  Kven  under  these  conditions,  if  there  is  a  dynamo  current 
present  for  other  purposes  flight  or  power),  it  may  often  be  employed 
with  economy  for  medical  purposes.  It  certainly  makes  it  much  easier 
to  keep  the  apparatus  in  running  order. 

Method  of  Measuring  the  Electromotive  Force  of  a  Voltaic  Cell.— 
This  is  most  accurately  accomplished  by  means  of  an  apparatus  called 
the  potentiometer.  This  is  essentially  a  balancing  of  the  electromotive 
force  to  be  measured  by  the  electromotive  force  of  a  standard  cell.  (See 
p.  IDo.) 

For  less  precise  measurement  of  the  electromotive  force  of  a  voltaic 
cell  a  galvanometer  with  a  certain  resistance  may  be  used,  and  this 
may  be  marked  in  amperes  or  volts.  In  either  case  the  instrument  may 
be  only  the  size  of  a  watch,  and  is  invaluable  for  such  purposes  as 
testing  the  condition  of  a  dry  cell  which  has  been  kept  in  the  shop  some 
time  before  being  sold,  and  perhaps  may  have  been  exhausted  in  con- 
sequence of  some  accidental  contact. 

The  Internal  Resistance  of  a  Voltaic  Cell.  —  The  current  from 
the  zinc  to  the  copper  through  the  dilute  sulphuric  acid  in  the  simple 
cell  which  we  have  described  encounters  a  certain  amount  of  resistance. 
This  internal  resistance  varies  with  the  different  cells  according  to 
the  component  parts  of  the  cell,  the  electrodes,  and  the  electrolyte, 
and  also  with  the  size  of  the  cell.  It  is  usually  equal  to  two  or  three 
ohms.  There  are  two  perfectly  easy  ways  of  determining  it.  One  way 
is  to  connect  the  poles  of  a  single  cell  with  a  galvanometer  and  note  the 
strength  of  the  current;  then  connect  two  such  cells  in  multiple,  for 
instance,  both  zincs  with  one  conducting  cord,  and  both  coppers  with  the 
other;  this  reduces  the  internal  resistance  one-half,  and  this  reduc- 
tion is  measured  by  introducing  a  variable  amount  of  resistance 
by  means  of  a  rheostat,  and  increasing  this  until  the  galvanometer 
indicates  the  same  current  strength  as  when  only  one  cell  was  used. 
The  increased  resistance  required  is  equal  to  half  the  internal  resist- 
ance of  a  single  cell.  The  formula  for  this  calculation  depends 

E 
upon  the  equation  C  =  -  ,  indicating  the  law  discovered  by  Ohm  that 

1\. 

the  current  is  equal  to  the  electromotive  force  divided  by  the  total 
resistance.  The  current  is  expressed  in  amperes,  the  electromotive 
force  in  volts,  and  the  resistance  in  ohms.  The  resistance  in  the  case 
we  are  considering  is  made  up  of  two  factors  —  the  resistance  of  the  cell 
itself,  K.  and  the  resistance  of  the  galvanometer  and  the  rest  of  the 
external  circuit,  r.  I'sing  a  single  cell,  therefore,  the  equation  would  read 

('-  '  :  and  if  the  additional  resistance  required  to  keep  the  same 
current  Mrength  in  the  case  of  two  cells  is  L.  then  the  equation  would 
read  ('-  :  and  since1  the  strength  of  the  current  ('  is  the  same 


on  p.  '2'-'>\.  The  knowledge  of  the  internal  resistance  of  a  voltaic  eel] 
i-  of  value  a>  one  of  the  fact  oi1.-  in  the  calculation  oi  the  number  and 
arraimement  of  cells  for  -ending  a  certain  number  of  amperes  of  cur- 
rent throimh  a  certain  number  «ii  ohms'  resistance. 


DYNAMIC    ELECTRICITY  (.b 

The  Original  Voltaic  Pile.-  Yollu,  professor  of  natural  philosophy 
at  Pavia,  in  17(.)(>,  devised  the  electric  battery,  from  which  all  those  so 
far  referred  to  as  sources  of  dynamic  electricity  have  been  evolved. 
It  consisted  of  a  series  of  two  different  metals,  piled  one  upon  the  other, 
and  separated  bv  cloth  or  paper  moistened  with  an  electrolyte.  The 
metals  were  sometimes  silver  and  /inc.  and  tlie  electrolyte,  water  or 
salt  and  water:  and  in  other  cases  zinc  and  copper  were  used  with  dilute 
acid.  The  current  was  produced  by  chemic  action  and  there  war-  no 
principle  involved  which  has  not  already  been  explained  in  describing 
tin1  modern  types  of  voltaic  battery.  At  the  upper  and  lower  extremi- 
ties of  the  pile  the  two  poles  of  the  battery  were  formed  by  dissimilar 
metal  disks.  Kach  pair  of  dissimilar  metals  separated  by  the  cloth 
moistened  with  the  electrolyte  formed  the  equivalent  of  one  of  the 
modern  voltaic  cells.  In  the  pile  the  zinc  element  of  one  couple  wa- 
in direct  contact  with  the  copper  element  of  the  next  couple,  the  succes- 
sion being  zinc,  moistened  disk,  copper,  zinc,  moistened  copper,  etc. 
It  formed  a  series  battery  the  voltage  of  which  could  be  raised  to  any 
reasonable1  amount  by  increasing  the  number  of  disks,  but  the  quantity 
of  current  was  very  small.  This  type  of  battery  is  not  in  use  to-day 
for  medical  work. 

Dynamic  Electricity  from  the  Contact  of  Dissimilar  Metals.— 
Two  dissimilar  metals  merely  placed  in  contact  in  the  air  will  produce 
an  electric  current,  but  this  is  most  powerful  when  one  of  the  metal- 
is  oxidizable  and  when  they  arc  dipped  in  a  good  electrolyte.  According 
to  Yolta's  observations,  any  of  the  metals  mentioned  in  his  contact 
series  becomes  electropositive  when  in  contact  with  any  one  below  it  in 
the  scale.  Starting  from  the  positive  end  of  the  scale  there  are  sodium, 
magnesium,  zinc.  lead.  tin.  iron,  copper,  silver,  gold,  platinum,  and 
graphite.  The  voltage  obtained  by  Yolta  by  the  contact  of  zinc  and 
lead  was  0.211);  tin  and  iron.  0..'Jb>:  even  cork  in  contact  with  platinum 
produces  an  electromotive  force  of  0,11.')  volt.  Two  different  metals 
in  contact  in  the  air  generate  electric  currents  whose  voltage  is  given 
in  the  foll< iwing: 

('ontttct  Si  rii's  of  .Vr/f;/.v  hi  Air. —  Kach  metal  is  4-  in  contact  with  all 
following:  Sodium,  magnesium,  zinc.  lead,  tin,  iron,  copper,  silver, 
gold,  platinum,  graphite.  Contact  K.M.F.  in  volts: 
o.L'10;  lead-tin.  O.OiiO:  tin-iron.  ()..'!  I.'-}:  iron-copper, 
platinum.  O.'JMS;  platinum-carbon,  0.  li:->  lAyrton  and  Perry). 

Heating  of  Voltaic  Cells. — The  amount  of  heal  generated  in 
a  voltaic  cell  depends  upon  the  chemic  constitution  of  the  cell,  not 
simply  upon  the  current  strength.  This  is  shown  in  the  cases  of  the 
cadmium  cell  and  the  Clark  cell.  Both  are  standard  cells.  They 
generate  a  perfectly  definite  electromotive  force,  which  is  used  in 
measuring  electromotive  forces  and  resistances.  The  cadmium  cell 
generates  thirty  times  less  heat  than  the  Clark  cell,  and  underlie- 
comparatively  little  change  in  electromotive  force  while  in  operation. 
Thi-  constitutes  a-  great  advantage  over  the  Clark  cell,  in  usinii  which 
the  temperature  changes  must  be  measured  and  their  effect  upon,  the 
electromotive  force1  calculated. 


THERMO-ELECTRICITY 

A   difference   in   potential    is   generated   when   the  junction   bet  wee 
two  different   metal-  is  heated  or  cooled,  and  this  will  produce  an  eler 
7 


MEDICAL    ELECTRICITY    AND    RONTC.EN    KAYS 

trie  current  if  the  two  other  extremities  of  the  metals  are  connected  by 
a  wire.  This  property  may  be  used  to  generate  electricity  for  medical 
purposes,  and  a  large  number  of  such  couples  will  give  a  cm-rent  of 
high  potential  or  of  great  quantity,  according  to  whether  they  are 
arranged  in  series  or  in  parallel.  As  long  as  a  difference  in  temperature 
is  maintained,  so  that  the  junction  of  the  metals  is  either  hotter  or 
cooler  than  the  distal  parts  of  the  metals,  a  current  will  flow.  Corrobo- 
rating the  theory  of  the  conservation  of  energy,  a  certain  amount  of 
energy  in  the  form  of  heat  must  be  applied,  and  disappears  as  heat,  to 
reappear  as  electricity. 

A  thermo-electric  pile  or  battery  is  not  convenient  for  therapeutic 
purposes,  but  it  may  be  used  as  a  very  delicate  thermometer. 

A  wire  of  one  metal  is'  bent  into  an  inverted 
U-shape,  as  in  Fig.  72,  and  others  of  another 
metal  are  soldered  to  its  two  extremities.  Plac- 
ing one  of  these  junctions  in  a  disk  of  melting 
ice  whose  temperature  is,  of  course,  known  to  be 
exactly  .'>2°  F.,  and  the  other  in  a  solution  whose 
temperature  is  to  be  tested,  a  current  of  elec- 
tricity will  flow  through  a  galvanometer  con- 
nected with  the  free  extremities  of  the  outside 
wires  if  there  is  any  difference  in  temperature  be- 
tween the  two  solutions.  The  galvanometer  devi- 
ations corresponding  to  different  temperatures 
must  be  determined  by  the  manufacturer  of  the 
apparatus  and  marked  upon  a  scale.  This  fur- 
nishes very  delicate  measurements  of  the  tem- 
perature of  any  part  of  the  human  or  animal  body,  to  which  one  point 
is  applied  while  the  other  point  is  dipped  in  melting  ice.  The  exact 
temperature  of  any  part  of  the  body  may  be  determined  in  this  way. 

Thermo-electric  Scale. — In  connection  with  lead,  at  a  mean  tem- 
perature of  20°  ('.  (.Matthiessen),  the  E.M.F.'s  are  in  microvolts  per 
degree  centigrade: 

I'.i-muth,  commercial,  in  wire -M  17.000 

pure,  in  wire ---S'.UIOO 

"        crystallized.,  alomr  axis +(1.1. 000 

normal  to  axis -:    l.VOOO 

Col,:,]!     j  I'!'. 000 

(iermaii  silver'...  .                             :    1  l.7.">0 

Merc  ir\  .  .  •  O.-US 


(  'i  ij  ,|  ii  T   n!    ci  1(1  111  lel'ci  • 

1111 

C,nl,\ 

Ant  inmny,  pure,  in  \\  ir 

'• 
Zinc,  " 


DYNAMIC    ELECTRICITY  90 

STORAGE  BATTERIES  OR  ACCUMULATORS 

These  are  cells  which,  after  being  charged  by  the  electrolytic  action 
of  a  current  passed  through  them,  act  exactly  as  do  the  ordinary 
voltaic  cells.  They  are  of  service  where  there  is  a  dynamo  or  similar 
source  of  electric  current,  which  is  either  not  available  at  all  hours,  or 
which  is  liable  to  derangement,  and  also  when  a  portable  outfit  is 
required.  The  general  principle  upon  which  all  storage  batteries  work 
is  illustrated  in  the  case  of  one  of  the  older  types  made  by  the  Thompson- 
Houston  Company.  It  contained  a  copper  electrode  at  the  bottom,  in 
a  solution  of  sulphate  of  zinc,  with  a  zinc  electrode  near  the  top.  A 
current  of  electricity  from  a  dynamo  or  from  a  primary  battery  was 
passed  through  this  cell  from  the  copper  to  the  zinc.  This  decomposed 
the  solution,  depositing  metallic  zinc,  upon  the  zinc  plate,  and  by  dis- 
solving away  the  copper  from  the  other  electrode,  produced  a  concen- 
trated solution  of  sulphate  of  copper  at  the  bottom  of  the  cell.  The  result 
was  the  formation  of  a  regular  Daniell  cell  of  the  gravity  type,  with 
the  zinc  electrode  at  the  top,  the  copper  at  the  bottom,  and  the  two 
electrolytes,  sulphate  of  zinc  solution  at  the  top,  and  sulphate  of  copper 
solution  at  the  bottom,  kept  separate  by  their  difference  in  specific 
gravity.  This  battery  was  then  ready  to  give  a  current  when  the 
external  circuit  was  made  between  the  two  poles.  The  direction  of 
the  current  of  discharge  was  the  reverse  of  that  of  the  charging  current, 
so  that  the  copper  became  the  positive  pole,  just  as  in  an  ordinary  gravity 
battery.  The  current-yield  would  continue,  while  the  external  curcuit 
was  closed,  until  the  solution  of  sulphate  of  copper  had  again  entirely 
changed  to  a  solution  of  zinc  sulphate.  The  battery  could  be  recharged 
by  passing  an  electric  current  through  it  in  the  same  way  as  at  first. 
And  this  alternate  charging  and  discharging  can  be  repeated  a  large 
number  of  times,  though  eventually  the  electrodes  are  worn  out  and 
the  electrolyte  also  needs  renewal.  While  charging  such  a  storage-cell, 
metallic  zinc  is  deposited  in  a  loose  form,  and  a  diaphragm  is  needed  to 
keep  it  from  falling  to  the  bottom  of  the  solution. 

The  Plante  Storage  Battery. — The  Plante  cell  is  the  original  upon 
which  the  other  modern  storage  batteries  are  modeled.  In  it  two  thin 
sheets  of  lead  separated  by  a  fraction  of  an  inch  are  coiled  together, 
securing  a  very  large  extent  of  surface  and  a  small  distance  at  all  points 
between  the  adjacent  surfaces  of  the  two  plates.  They  are  set  in  a  jar 
of  dilute  sulphuric  acid,  and  a  conducting  cord  is  attached  to  each 
plate.  In  this  condition  no  current  is  produced  on  closing  the  circuit, 
because  both  plates  have  exactly  the  same  affinity  for  the  electrolyte 
and  no  difference  in  potential  exists.  The  battery  is  charged  bv  passing 
a  current  of  electricity  through  it.  Electrolysis  or  electrochemic 
decomposition  takes  place,  by  which  the  lead  plate  connected  with 
the  negative  source  of  electricity  becomes  coated  with  finch"  divided 
metallic  lead,  derived  from  the  action  of  the  acid  upon  the  other  plate, 
-url'ace  of  that  one  becomes  converted  into  red  lead  or  peroxid 

ile.  then,  with  the  storage-cell  fullv  charged,  we  have 
and   at   the  other,    I'M),.      Removing   the   battery 
current,  it    is  ready  to  act    like  an  ordinary  voltaic; 
a  current  when  its  two  poles  are  connected  through 
The  pole  on  which  the  I'M).,  nvd  lead  or  peroxid 

deposited  becomes  the  positive  polo  of 

his  to  the  01 


MKD1CAI.    KLK<  TRK  Tl'Y    AM)    KnXTOK.N     HAYS 

In  The  liquid  electrolyte  of  the  battery,  of  course,  the  current  is  con- 
tinued t'ri'in  the  Pb  to  the  PbO...  The  react  mn  occurring  as  the  total 
result  of  the  discharge  of  a  storage  buttery  is  Pb  -  PbO.,  -  21I,S< ),  ,  2Pb- 
S«  i.  •  2H..O.  uti'i  during  the  process  of  charging  or  recharging  the  saine 
equation'holds  good,  but  would  be  reversed:  2Pb.SO,  •  2H..O  Pb  - 
rbo.,  -2H,SO4. 

In  other  words,  during  the  discharge,  the  metallic  lead  on  one  plate 
and  the  peroxid  of  lead  on  the  other  both  yield  to  the  influence  of  the 
sulphuric  acid  and  are  converted  into  sulphate.  The  dilute  sulphuric 
acid  becomes  weakened,  and  solid  sulphate;  of  lead  is  produced.  It  is 
ne\  er  desirable  to  allow  a  storage  battery  to  become  completely  dis- 
charged, all  the  peroxid  of  lead  disappearing,  both  plates  becoming 
converted  into  PbO.  or  litharge,  and  the  electromotive  force  falling  to 
xero.  In  this  condition  it  receives  a  charge  much  less  readily  and 
effectually  than  if  one  plate  still  had  a  considerable  coaxing  of  peroxid 
of  lead.  For  the  same  reason,  when  first  making  a  storage  battery,  it  is 
preferable  to  apply  a  thick  coat  of  peroxid  of  lead  i  red  lead)  to  one  or 
both  of  the  lead  plates,  the  battery  then  "forming1'  much  more  quickly. 

.More  closely  atialyxed.  the  reaction  in  a  storage  battery  during  its 
discharge  consists  partly  in  the  formation  of  about  equal  quantities  of 
solid  lead  sulphate  at  each  pole,  and  a  reduction  (.if  the  strength  of  the 
acid  occurs  at  both  poles,  but  is  more  marked  at  the  positive  pole.  One 
result  of  the  discharge  is  seen  at  the  anode,  -where  the  lead  combines 
with  a  sulphion  to  ft >rm  sulphate  of  lead,  and  transfers  a  negat  ive  charge 
of  electricity  to  the  liquid  in  the  direction  of  the  cathode.  The  equation 
Pb  -.SO,  PbSO,-;-2—  expresses  the  reaction  occurring  at  the  positive 
pole.  The  reaction  at  the  cathode  is  exprc.-sed  by  the  equation  PbO.,-1- 
If  ..SO,  -I'll.  _'--•  PbSO^-L'ILO.  which  indicates  that  peroxid  of  lead. 
with  sulphuric  acid  and  hydrogen  and  a  negative  charge,  result  in  the 
formation  of  sulphate  of  lead  and  water. 

When  the  storage  battery  is  being  charged,  the  same  equations  also 
hold  good,  but  are  simply  reversed. 

Wit  h  t  he  strength  of  acid  i  >rdinarily  used,  a  storage-cell  cool-  slight  !y 
while  yielding  a  current.  The  full  explanation  of  why  this  should  be 
the  '•.;-(•  instead  of  the  fluid  becoming  warm,  as  with  the  Daniell  cell, 
i.-  beyond  the  scope  of  the  present  book.  But  two  factors  are  that  the 
re-  i  Its  i  ft  he  chemic  "hange  are  much  weakened  acid  and  solid  lead 
>ulphaie.  and  that  the  internal  resistance'  of  a  storage-cell  is  very  much 
-i  .  er  -  .  I  hat  of  an  ordinary  voltaic  cell.  \\hen  a  .-torage  battery 
i-  beii  '_:  reel  arged.  t  he  electrolyte  acquires  its  con  d  it  ion  of  being  quite  a 
strong  solutioi  o]  -ulphuric  acid,  and  the  prof-ess  should  be  continued 
11111  .  '_'.-:-<•-  are  freel'  given  off  from  the  electrolyte,  which  becomes 
slightlv  warm  during  the  process  These  ga-e-  are  hydrogen  and 
•  •xyirei  .  '  ,  '  e  pre-em-c  of  ;i  spark  or  flame  would  cause  an  ex  pi  o- ion. 
The  large  bubhle<  are  hydrogen.  1  he  small  one-,  oxygen.  The  sulphuric 
acid  ei  as  a  den  sit  v  of  ]  .Is  or  1 .20.  and  is  much  stronger 

than  "dilute  sulphuric  acid."  A-  the  water  evaporates,  di.-tilled  water 
is  t  he  be^t  to  ;i  .  -  i>e  it  brings  about  no  change  in  1  he  com  posit  ion 
ol  the  electrolyte,  while  ovdinarv  water  contains  an  amount  of  chlorids 
•  '  er -everal  addit  ion-,  to  impair  1  he  efficiency  of  t  he  cell. 

'I  he  modern  storage  battery  i-  made  up  of  grid-,  which  are  molded 
form-  of  lead  producing  hardly  more  ':;i'i  a  framework  until  thev  are 
'"'pasted."  The  Lrrid  which  i-  to  form  the  ]io-iii\-e  pole  of  the  storage 


DYNAMIC     KI.KCTKK  1'1'V 


101 


batterv  is  ''  pasted, "  or  thoroughly  tilled  under  hydraulic  prosMiio. 
with  a  paste  of  ml  lead  and  some  substance  which  will  he  dissolved  out 
l>v  the  \veak  sulphuric  acid,  and  leave  a  porous  mas-;  presenting  a  rela- 
tively very  lar^e  surface  of  peroxid  of  lead  exposed  to  chemic  action. 
The  other  .arid  is  pasted  in  the  same  way  with  spongy  lead.  The  active 
surfaces  presented  are  ahout  '200  or  100  square  inches  per  pound.  '1  IMS 
met  hod  of  construction  also  prevents  t  he  separat  ion  of  1  he  act  ive  layer. 
The  surfaces  of  the  positive  and  negative  "rids  are  placed  very  close 
together,  being  kept  from  actual  contact  hy  a  corrugated  sheet  of  hard 
rubber  with  numerous  perforations,  and  also  by  a  thin  piece  of  bass 
wood.  The  latter,  under  the  action  of  the  acid,  becomes  :',0  per  cent, 
porous,  but  still  has  such  fine  pores  that  it  effectually  prevents  the 
formation  of  a  lead  tree.  The  hitter  is  a  sort  of  crystalline  mass  ot  lead, 
looking  like  the  familiar  Christmas  tree,  which  would  have  a  tendency 


- 


to  form  between  two  lead  plates  in  a  storage  batterv  and  very  greatly 
impair  the  efficiency  of  the  battery.  A  storage  battery  is  usually  made 
up  with  three  positive  ami  two  negative  "'rids  in  each  cell.  This  does 
not  increase  the  voltage  of  the  cell  over  what  would  be  the  case  with 
only  one  plate  ot  each  kind.  It  does,  however,  increase  the  amperage 
and  does  so  in  a  manner  more  economical  in  regard  to  sixe  and  weight 
than  \vi  ni  Id  be  the  ca.se  wit  h  a  single  pair  of  c<  irrespom  tingl  v  larger  plat  es. 
Five  such  cells  would  have  a  potential  of  about  10  volts,  and  would 
give  a  current  of  about  10  amperes,  through  a  resistance  of  I  ohm.  for 
about  ten  hour-  continuously,  or  as  the  total  of  several  shorter  periods. 
A  bat  tery  of  t  his  capacit  v  weighs  in  mi  100  to  -00  pound-. 

The  chlorid  type  of  storage  battery,  made  bv  th.->  (Electric  >'"vaiM 
Battery  Company,   em])loys  antimony   irrids.   with   button-   of   peroxid 


1"2  MKDICAI.    KLKCTKKTI  Y    AX1)    KOXTCKX    HAYS 

of  lead  on  the  negative  and  of  metallic  lead  on  the  positive  plate.  Each 
cell  contains  several  positive  and  several  negative  plates,  and  a  cell 
Hi  inches  high  and  weighing,  when  filled  with  -10  pounds  of  weak  acid, 
bio  pounds,  will  give  2.~>  amperes  for  eight  hours  or  .'-Jo  amperes  for  four 
hours,  or  oO  amperes  lor  three  hour-,  or  100  amperes  for  one  hour. 
Its  potential  is  only  2  volts,  and  to  obtain  the  heavier  currents  it  is 
necessary  to  have  several  such  cells  connected  up  in  series. 

The  Edison  storage  battery  has  positive  and  negative  plates  of  thin 
nickel  steel,  wit  h  pern  irat  ions  in  which  t  he  active  material  is  consolidated 
under  hydraulic  pressure.  The  surface  of  the  positive  plate  is  made 
up  of  powdered  peroxid  of  nickel  mixed  with  powdered  graphite;  the 
negative  plate  contains  powdered  oxid  of  iron  and  graphite.  The 
electrolyte1  is  an  aqueous  solution  of  caustic  potash.  Passing  a  current 
through  the  cell  in  order  to  charge  it  converts  the  positive  plate  into 
hyperoxid  of  nickel  and  -the  negative  plate  into  spongy  metallic  iron. 
After  discharge  the  grids  are  covered  with  peroxid  of  nickel  and  oxid 
of  iron.  There  are  a  number  of  plates  in  each  cell;  its  voltage  is  l.o, 
and  it  is  a  much  lighter  cell  than  the  lead  storage-cell. 

Faure's  Accumulator. — A  single  cell  consists  of  two  lead  plates 
coated  with  a  paste  of  minium  (Pb3O4),  with  dilute  sulphuric  acid 
t,II_,SO}).  The  coated  plates  are  covered  with  felt  or  cloth,  to  prevent 
contact  with  each  other,  and  are  rolled  up  together  and  immersed 
in  dilute  sulphuric  acid.  The  following  reaction  takes  place  in  both 
plates  befo'j:1  the  application  of  any  current.  The  sulphuric  acid  acts 
upon  the  minium:  Pb304  +  2H,S04  =  PbO,  +  PbSO4  +  2H,O.  If  a 
charging  current  from  a  battery  or  dynamo  is  now  applied,  there  is  the 
following  result  at  the  plate  connected  with  the  positive  wire  from  the 
dynamo:  Pb.SO1-H/J  +  0  =  PbO,-fH,S04.  In  other  words,  the  elec- 
trolytic liberation  of  oxygen  at  the  positive  electrode  results  in  a  complex 
reaction,  producing  an  additional  deposit  of  PbO.,  and  an  increased 
amount  of  II., SO,.  At  the  plate  connected  with  the  negative  wire  from 
1  he  dynamo  a  contrary  effect  is  produced.  It  is  one  of  deoxidation,  and 
t  he  I'b(  ).,  and  I'bS<  ),  are  both  reduced  to  spongy  metallic  lead:  the  other 
products  there  being  II  ,SO(  and  H.,O.  After  being  completely  charged, 
the  storage-cell  i<  capable  of  giving  a  current  of  electricity  if  the  two 
plate<  are  connected  by  means  of  an  external  circuit.  The  current 
will  be  in  the  opposite  direction  to  the  charging  current,  and  has  an 
electromotive  force  of  about  2  volts,  The  reaction  at  each  plate  (luring 
disci  large  just  reverse.-;  t  hat  occurring  while  1  lie  battery  is  being  charged. 

The  care  of  a  storage  battery  consists  chiefly  in  charging  and 
rechargintr  it.  seeing  that  it  doe-  not  become  short-circuited,  and  that 
the  fluid  i-  maintained  at  the  original  quantity  and  strength. 

\\hen  out  ot  -ervice  tor  more  than  a  month  or  two  the  storage 
battery  ,-hould  be  fully  charged,  washed  out  thoroughly  with  di-tilled 
water,  arid  kepi  empfv  of  all  liquid.  Neglect  of  this  care  results  in 
"sulphating"  or  irreparable  de-triiciion  of  the  plate-  by  the  acid. 

Charging  a  Storage  Battery.-  Figure  74.  . I,  shows  the  connections 
to  be  made  when  the  -lorage  battery  i>  charged  from  the  110  volt< 
direct  incandesceni  h^h'  circuit.  From  the  po-itivc  wire  the  current  is 
led  acro-~  a  fused  knife  -witch  to  a  bank  of  four  1(1  c.  p.  incandescent 
lamp-,  arranged  in  parallel,  and  acting  as  a  resistance,  so  that  only  the 
de.-in-d  current  .-trength  of  three  ampere-  or  >o  can  pa-s  through  the 


DYNAMIC    KLKCTHICITY 


103 


storage  battery.  From  the  hank  of  incandescent  lamps  the  positive 
current  is  led  to  the  positive  pole  of  the  storage  battery  (connecting  the 
positive  elect  ric-light  wire  with  the  wrong  pole  of  the  storage  battery 
would  product1  damage),  and  thence  across  a  fused  knife  switch  1o  the 
negative  electric-light  wire.  It  takes  about  ten  hours  to  charge  a 
storage  battery. 

Figure;  74,  B  shows  the  arrangement  for  charging  a  storage  battery 
from  the  o.">0  volts  direct  current  of  the  trolley-car  system.  The 
difference  to  be  noted  is  that  the  bunk  of  incandescent  lamps  consists  of 
five  parallel  series  of  five  Hi  c.  p.  incandescent  lamps  each.  This  results 
in  the  same  current  strength  reaching  the  positive  pole  of  the  storage 
battery,  as  in  the  case  of  the  110  volts  direct  current  controlled  by  the 
single  lamps  in  parallel. 


/Veoaftyf    w/re 

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a 


£  foray  r 

74.. I.  —  For  110  volt- 


direct  current.        Fig.  74,  B. — For  ooO   volts   direct    current 
from  the  trolle.v  svstoin. 


Where  the  current  is  supplied  by  an  alternating  incandescent  light 
circuit  of  110  or  125  volts,  it  is  necessary  to  have  the  current  changed 
so  as  to  be  unidirectional.  This  is  accomplished  by  introducing  a 
mercury  arc  rectifier  into  the  circuit  between  one  incandescent  light 
wire  and  the  storage  battery,  with  its  bank  of  lamps  t<>  regulate  the 
strength  of  the  current. 

The  w(vr ///•//  a/'c  rectifier  consists  of  a  vacuum  tube  with  a  reservoir 
of  mercury  at  the  bottom  which  forms  the  cathode,  with  which  one 


$  

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B&Htr/ 

MKI>I<  AL     KLKi  TKHITY    AND    H<  )NT(  iKX    KAYS 


iron  anodes.  The  cathode  in  a  vacuum  tube  has  a  reluctance  which 
mu-t  l»e  overcome  l>y  the  disintegration  of  its  surface.  And  if  such  a 
tube  i-  -imply  interposed  hetween  the  positive  pole  of  the  storage 
batterv  and  one  incandescent  light  wire,  while  the  other  pole  of  the 
storage  battery  i-  connected  with  the  oilier  incandescent  light  wire, 
no  current  will  pass.  The  terminal-  .1  and  <i  in  the  mercury  vapor 
vacuum  tube  i  Fi<i.  7">  >  will  remain  as  completely  insulated  as  if  they 
were  separated  by  an  inch  or  two  in  the  open  ail'.  The  surface  of  .1 
may.  however,  be  disintegrated  and  .1  be  made  1o  act  as  a  cathode 
and  permit  the  ilow  of  current-  iti  the  direction  from  a.  to  .1.  And  this 
can  lie  done  without  disintegrating  the  surface  of  a.  which  remains 
incapable  oi  acting  as  a  cathode,  and  t he  tube  will  not  transmit  currents 
m  the  direction  from  .1  to  a.  '1'here  are  thus  transmit  ted  through  tlie 
storage  battery  a  siicce-sion  o|  current.-  in  onlv  one  direction  and  care 
i-  taken  to  have  the  connection  made  A\ith  the  proper  poles  of  the, 
storage  battery.  I'lns  succession  of  currents  may  be  made  an  almost 
continuous  current  by  introducing  a  self-induction  coil  at  K.  l^u-h 
lin  e  the  current  ceases  to  (low.  an  extra  current  in  the  .-a me  direction 
.-  produced  by  inductance.  '1  he  other  side  of  the  diagram  shows  the 
arrangement  lor  disintegrating  the  surface  of  the  mercurv  cathode  ,1, 
and  keeping  it  so,  and  constantly  in  condition  to  act  as  a  cathode. 
-  accoiiijdished  by  first  sending  an  induction  .-park  from  the  other 
•Mo  .  1 .  and  following  this  up  with  a  constant  current  of  Ml  ampere- 
and  11  volts,  between  the  same  points.  A  storage  battery  b  supplies 


'    a  ce     the  mill;       IT  primary  discharge  by  means  ol 

a  .-el;  •    e        ;iiid  a  quick  1  ireak  -wil  ch. 

I:,    liic   :,    ra!iLrei    >      '    '      is    far  de-cribed    t  he]-e   i-   a    direct    connection 
ln-t'.'.-een    •     e    dvnamo    circiiil    and    the    -toi'a.U'e    battei'X'    U'hich    is    being 
•  n   only  !  alf  •  :   thn  current:    from  the  dynamo  are  utihxed  in 
ati\    '.vay. 

[•"in.  7'i -ho\v-   an    arranLrenient    bv    which    both   sets  of  current-;  are 

•  d  irect  ]  v  bv  means  of  secondary  induct  ion  coils.       I  he  va<  mini 

hilji  be  pr'u    ed.  or  t  he  current  si  a  Tied  through  it   by  a  .-purl,  from 

a    -toraire    ba'terv    and    a    self-induction    coil.      After    that    an    induced 


DYNAMIC     KLKCTUHITV 


10.1 


current  is  -ent  through  the  vacuum  tube  from  two  secondary  coils 
alternately.  These  two  coils  have  the  same  number  of  similar  turn-, 
but  in  the  opposite  direction.  Currents  are  excited  in  one  of  these  by 
the  alternating  current  in  the  primary  coil.  One  of  the  secondary  coil- 
is  connected  with  one  anode  of  the  vacuum  tube,  on  the  one  hand,  and 
with  a  self-induction  coil  and  a  storage  battery  and  1  he  mercury  cathode, 
on  the  other  hand.  The  other  secondary  coil  forms  part  of  a  similar 
complete  circuit  starting  from  the  other  anode  of  the  vacuum  tube. 
The  surface  of  the  mercury  is  disintegrated  by  a  spark  irom  the  priming 
batterv,  and  thereafter  no  battery  current  is  necessary,  only  the  sec- 
ondary currents;  and  their  potential  is  kept  from  falling  to  zero  by  the; 
presence;  of  the  self-induction  coils.  Kach  secondary  coil  sends  impulses 
in  both  directions,  but  only  those  in  the  direction  from  the  anode  to 
the  cathode  can  pass  through  the  mercury  vapor  tube.  There  are 
currents  in  this  direction  practically  all  the  time;  when  one  coil  is  not 
sending  one.  the  other  is. 

A  similar  arrangement  is  used  to  rectify  Iriplxtw  current*,  the  trans- 
former having  three  secondary  coils.  And  Mr.  Cooper  Hewitt  reports 
that  he  has  succeeded  in  making  a  rectifier  supplying  a  direct  continuous 
current  of  :>0  amperes  and  ">()()  volts  with  an  efficiency  of  US  per  cent. 

A  t/icclitinic  reed /icr  fur  alternating  currents  !i>r  use  in  charging  storauv 
batteries  may  consist  of  a  step-down  transformer  to  reduce  the  voltage 


to  the  figure    required,  and    an  electric  vibrator  on  the  same 
a-  all   electric  bell.      This   is  regulated  so  that    the  contact    is  n 
a  I  1  lie  limes  when  t  he  current  is  Id  iwinir  in  the  same  direct  ion. 
apparatus  devised  by  Soiilier1   issaid  to  run  perfect  lv  steadilv 


1UI) 


MEDICAL    KLKCTHICITV    AND    RONTC'.KN    HAYS 


time,   and   not    to   become   hot    like  electrolytic   rectifiers.      It    has   no 
liquid  to  be  renewed,  and  consumes  less  current. 

Electrolytic  r<ctifnrx  are  on  the  same  principle  as  the  aluminum 
cell  u-ed  to  rectify  an  alternating  current  for  ,r-rav  work.  They  are 
the  simple-t  and  cheapest  thing  for  transforming  either  an  alternating 
or  a  tripha-e  current  into  a  direct  current  for  charging  a  storage  battery. 
The  rectifier  consists  of  four  of  the  "aluminum  cells"  shown  in  Fig.  77, 
where  three  sets  of  different  sixes  are  shown.  A  set  of  four  of  the  sixe 
corresponding  with  the  -ixe  of  the  storage  battery  to  be  charged  are  con- 
nected, a-  >hown  in  Fig.  7s.  One  alternating  current  wire  is  connected 
with  the  lead  of  one  cell  and  with  the  aluminum  of  another.  The  other 
iv  ire  of  the  alternating  circuit  is  connected  with  the  lead  of  the  third 
and  with  the  aluminum  of  the  fourth  cell.  The  wire  which  is  to  deliver 
tlii'  positive  current  to  the  storage  battery  is  connected  with  the  alumi- 
num of  the  two  cells,  whose  lead  is  connected  with  the  two  alternating 
current  wires.  The  negative  wire  comes  from  the  lead  of  the  two  cells 
whose  aluminum  is  connected  with  the  alternating  current  wires.  In 
regard  to  any  one  cell  polarization  prevents  the  flow  of  the  current  in 
one  direction,  while  offering  very  little  obstruction  in  the  other.  At 
each  alternation  in  the  primary  current  cells  1  and  ,'i  take  turns  in 

allowing  a  current  to  pass  in  the 
direction  indicated,  and  so  do  cells 
2  and  4.  The  fluid  used  is  a  strong 
solution  of  Kochelle  salt. 

A  Booster.  —  In  the  power- 
houses of  the  trolley-car  system 
the  storage;  batteries  are  of  tre- 
mendous power  and  are  formed  bv 
a  series  of  hundreds  of  large  cells 
and  require  a  greater  voltage  than 
that  of  the  line  wire  to  charge 
them.  So  that  instead  of  having 
to  use  a  reduced  voltage, 
small  establishments,  it  is 
savy  to  supply  a  current 
This  i: 


general  or,   which    is    called    a   boo 
expression  for  help  up  i  ir  pu.-h  up. 

~e  of  i  he  \vord  hi  niftier  designates  a  step-up  transformer  for 
a'_!;e  alternat  ing  cm-rent  . 

nay  be  used  in  parallel  ("multiple")  or  in  series  or  a 
he  two,  just  like  ordinary  voltaic  cells.  Their  large 
ability  1  '  i  recharge  1  hem  con: 

crapeut  ic  \vi  irk. 
'     necessarv  when   a  |  »  'Tt  a! 
\vork    where   a    dvnam 


UlVltlli'   higher   vo 
Si  i  irage-eells  ! 

coiiil  iinat  ion    '  if   1 

cat  lacit  v  am  \  t  he 

tatres  l'i  ii1  mai 

"I  he;     arc  e-pc 

is    iv  i        cd    , 


it  ute  verv  irreal  ad van- 


THE   PRODUCTION   OF   ELECTRICITY   BY  ELECTROMAGNETIC   INDUCTION 

I'  i'  e'  '        p  irp"-e  iviuiriim  a  lai'irc  amouiit  of  electric  current 


DYNAMIC:  KLKCTKICITY 


107 


and  similar  generators.  These  all  depend  upon  the  principle  that  the 
motion  of  a  magnet  or  of  a  coil  of  wire  through  which  a  current  of  elec- 
tricity is  passing  will  induce  an  electric  current  in  a  neighboring  coil  of 
wire.  It  was  natural  to  expect  that  currents  of  electricity  in  one  wire 
would  produce  currents  of  the  same  general  sort  in  another  wire,  hut 
it  was  a  discovery  of  the  greatest  importance  when  Michael  Faraday, 
in  1831,  found  that  the  motion  of  magnets  would  generate;  electric 
currents  in  neighboring  wires.  This  had  been  preceded  and  was  led 
up  to  by  Oersted's  discovery  that  a  current  of  electricity  in  a  wire  will 
induce  magnetism  in  a  neighboring  iron  or  steel  rod. 

The  relation  between  electricity  and  magnetism  is  most  intimate, 
and  it  requires  only  the  proper  apparatus  to  convert  force  manifested 
as  electricity  into  force  manifested  as  magnetism,  or  vice  versa.  There 
are  several  important  properties  which  illustrate  this  relation,  and 
which  are  used  in  the  construction  of  apparatus  for  the  production, 
measurement,  or  regulation  of  electricity  for  medical  purposes. 

Directive  Effect  of  Dynamic  Electricity  Upon  a  Magnetic  Needle.— 
A  current  of  electricity  passing  through  a  wire  causes  a  magnetic 
needle,  like  a  compass  needle,  to  tend  to  assume  a  position  at  a  right 
angle  to  the  direction  of  the  current.  If  the  wire  is  above  the  needle 
and  the  current  is  passing  from  south  to  north,  the  needle  will  turn  with 
its  north  pole  to  the  west.  When  the  current  passes  below  the  needle, 
but  from  north  to  south,  the  needle  will  again  deviate  to  the  west. 
The1  needle  type  of  galvanometer  measures  the  strength  of  the;  current 
by  the  amount  of  deviation  produced. 


Magnetizing  Effect  of  Dynamic  Electricity  upon  Iron  and  Steel. — 

A  bar  of  steel  surrounded  by  a.  coil  of  wire  through  which  a  current  of 
elect  I'icity  passes  becomes  a  magnet,  and  the  question  as  to  which  end 
of  the  steel  becomes  the  north  pole-  depends  upon  the  direction  in 
which  the  currcMit  passes,  from  right  to  left,  or  vice  versa. 

Fig.  70  represents  the  case1  of  a  straight  wire  crossing  above  a  steel 
bar.  and  the  current  passing  in  the  direction  indicated  by  the  arrows 
The  steel  bar  becomes  a  magnet  with  its  north  pole  at  the  end  indicated 
by  N,  and  its  south  pole  at  S.  In  this  diagram  more  clearly  than  m 
any  other  case  is  shown  the  truth  of  one  rule  for  determining  which 
pole  of  an  electromagnet  is  the  north  and  which  the  south.  The  r  lie 
is  that  a  person  swimming  with  the  current  of  electricity  at  any  part 
oi  the  wire  and  facing  the  electromagnet  will  have  the  north  pule  at 
his  left  hand.  If  the  arrows  indicating  the  direction  were.1  reversed, 
the  poles  of  the1  electromagnet  would  also  be  revered. 


I  OS 


MKD1CAL    KLIXTKICITY    AND    H()NT(iKN    HAYS 


Fiirure  SI  show-  the  po-ition  of  the  induced  magnetic  poles  when  the 
wire  form>  a  single  loop  passing  around  the  steel  bar  in  a  plane  at  a  I  unit 
a  riidit  almle  to  its  lon<r  axis.  In  such  a  case  the  rule  mo-t  readily 
applied  i-  that  if  one  end  of  the  coil  he  toward  the  observer  and  the 


current   i-  pa.— inu  in  the  direction  of  the  hands  of  a  watch,  then  it  is 
the  -outh  magnetic  pole  which  is  induced  at  that  end. 

Figure  V>  shows  the  idea  of  a  ri^ht-liaiuU  d  spiral,  ai.d  if  the  ciu'rent 
Mow-  in  the  direction  indicated  by  tin1  arrow.  /'.  e.,  in  the  direction  of 
thr  hand-  i,f  a  watch,  the  pole  touard  the  observer  is  the  south  pole. 


'• 


• 


It   the  current   \vere  flowing  in  the  opposite  direct  i^n.  throtiji'li  the  same 
flexH'ovsal    or    riu'ht -handed  -piral.   the    polarity   ol    the    elect I'ornau'iiet 

\\'i  iiild  be  reversed. 

riu-ure  Mi  -ho\\<  the  idea  of  a   left-handed  spii'al.  and  if  the  current 
flows  contrary  to  the  hand-  of  a  watch,  as  indicated  bv  the  arrow,  the 


neare-1    the  observer.      If   the   current    flowed    in 
•  direction,  the  magnetic  polarity  would  be  reversed. 
7  represent-  t  he  ca-e  of  a  i'i<rl it -handed  helix  in  which  t  he  wire 
:  a  curve  tVniii  one  (lid  to  the  other,  and  then  back  to  the 


DYNAMIC    ELECTRICITY 


100 


firsi  end.  still  continuing  1o  puss  around  the  axis  in  t  ho  same  right- 
handed  direction  throughout.  This  is  the  way  in  which  thread  is 
<''enerallv  wound  upon  a  spool.  Both  layers  act  in  the  same  way  to 
induce  a  south  magnetic  pole  at  the  end  where  ihe  current  is  seen  by 
tlie  observer  to  pass  in  the  direction  of  the  hands  of  a  watch.  In  the, 


a  current  through  a  flat  .spiral. 


same  diagram,  if  the  arrows  indicating  the  direction  of  the  electric 
current  \vere  reversed,  the  polarity  of  the  magnet  would  also  lie  reversed. 
The  diagram  as  shown  in  the  engraving  illustrates  the  case  of  tin;  usual 
electromagnet  except  that  in  actual  practice  it  is  not  necessary  to  have 
the  turns  widely  separated.  They  are  really  wound  as  closely  as  thread 
upon  a  -pool,  the  current  being  confined  and  made  to  pass  through 
the  many  turns  of  wire  by  the  insulation  of  the  latter.  If  a  bare  wire 
were  closely  wound  in  this  way,  the  current  would  pass  from  one  end  ot 
the  coil  to  the  other  over  the  shortest  path  provided  by  the  contact  of 
different  turns  with  each  other.  Very  little  current  would  pass  through 


the  whole  length  of  the  wire,  and  the  resulting  magnetization  would 
be  very  weak. 

Figure  SS  shows  1  he  case  of  a  flat  spiral  surrounding  a  steel  bar  which 
is  at  a  right  angle  to  the  plane  of  the  spiral.  Here  again  the  direction 
of  the  current  with  the  hands  of  a  watch  at  the  end  near  the  observer, 
shows  that  this  is  the  south  pole  of  the  induced  magnet.  The  spiral 
in  the  diagram  is  a  right-handed  one,  but  here,  as  in  all  other  cases,  the 
polarity  of  the  induced  magnetism  is  not  controlled  by  the  direction 
in  which  the  wire  is  wound,  but  by  the  direction  in  which  the  current 
passes  through  the  wire.  The  amount  of  induction  is  practically  the 
same  as  with  the  same  number  of  turns  in  the  form  of  ;i  helix. 

The  following  diagrams  from  Houston  (Fig.  80)  give  an  exceedingly 
easy  way  to  determine  the  polarity  of  an  electromagnet  when  the 
direction  of. the  current  is  known.  At  the  north  pole  of  the  induced 


110  MEDICAL    ELECTRICITY    AND    ROXTGEX    RAYS 

magnet  the  arrows  on  the  letter  X  indicate  the  direction  of  the  current. 

and  similarly  with  the  letter  S  at  the  south  end. 

A  steel  bar  which  has  been  magnetized  by  an  electric  current  retains 
its  magnetism  and  is  a  permanent  magnet. 

A  soft-iron  (wrought  iron  or  malleable  iron)  rod  becomes  an  equally 
strong  magnet  almost  the  instant  the  current  is  turned  on.  but  loses 
its  magnetism  almost  the  instant  the  current  is  turned  off.  In  many 
forms  of  apparatus  for  use  in  medicine  this  alternation  from  a  condition 
of  powerful  magnetism  to  practically  complete  absence  of  magnetism 
takes  place  thousands  of  times  a  minute. 

Magnetization  During  the  Flow  of  the  Current. — From  the 
time  the  current  is  turned  on  until  it  is  turned  off  the  soft-iron  rod 
remains  an  equally  strong  magnet  and  with  its  polarity  unchanged. 
This  is  the  case  when  the  electric  current  is  uniform  as  to  direction  and 
strength.  Any  variation  in  either  the  polarity  or  strength  of  the  electric 
current  will  produce  a  corresponding  change  in  the  polarity  or  strength 
of  the  magnet.  It  is  important  to  remember  that  the  effect  of  an 
electric  current  upon  an  iron  core  is  continuous  as  long  as  the  current 
lasts.  This  is  not  the  case  with  two  other  forms  of  induction,  which  we 
shall  have  to  consider.  A  current  of  electricity  induced  in  a  coil  by  a 
magnet  is  only  momentary,  and  occurs  only  when  the  magnet  is  carried 
toward  or  away  from  the  coil.  The  electric  current  does  not  continue 
to  flow  while  the  magnet  is  at  rest  within  the  coil  or  anywhere  else. 
The  other  case  is  that  of  electric  currents  induced  in  other  wires  by  a 
current  passing  through  a  primary  wire.  The  currents  are  induced 
only  when  the  primary  current  is  made  or  broken,  or  when  its  strength  is, 
increased  or  diminished,  or  when  it  is  brought  near  to  or  away  from  the 
secondary  wire,  and  in  either  case  it  is  of  momentary  duration.  Xo 
electric  induction  takes  place  during  the  uniform  flow  of  an  electric- 
current,  but  that  same  uniform  flow  will  maintain  magnetic  induction 
in  an  iron  core. 

Magnetic  Properties  of  Voltaic  Currents. — Iron  filings  are 
attracted  by  every  part  of  a  wire  through  which  an  electric  current  is 
flowing,  and  if  the  wire  is  passed  vertically  through  a  hole  in  a  piece  of 
paper  on  which  iron  filings  have  been  sprinkled,  the  latter  will  arrange 
themselves  in  concentric  rings  corresponding  to  the  lines  of  force 
familiar  to  us  in  the  case  of  the  ordinary  magnet.  The  lines  of  force 
in  the  case  of  a  wire  through  which  an  electric  current  is  pas-ing  are  in 

ind  pass  around  the 
rection  which  depends- 


las  tob 

e  1  urne 

1  1    as    it    pus 

lies 

icte  i    a 

snleno 

id     Fig.90) 

or 

•Dial   po 

-it  :<  Hi,  ; 

Hind  t 

hat 

uu'h  it. 

the  sol, 

•in  'id  pi  isses 

sed 

a  nort 

h  and   - 

<  'in  h  i  lirect  i 

on. 

.      And 

ii  such 

a  coil  is  Me; 

ir  a 

in   rela 

'  1  1   the   ma  g 

net 

The  d\ 

\rsonv; 

:  lereiiK 

'ter 

DYNAMIC    ELECTRICITY 


111 


in  electrotherapeutics,  depends  upon  this  principle;  tho  stronger  the 
electric  current  which  passes  through  the  coil,  the  stronger  its  mag- 
net ism,  and  tho  greater  its  deviation  under  the  influence  of  a  stationary 
permanent  magnet. 

A  single  loop  of  wire  (Fig.  90)  through  which  an  electric  current  is 


Fig.  90.  — Direction  of  the  lines  of  force  or  magnetic  whorls  about  a  current  of  electricity. 


passing  has  the  properties  of  a  magnet  whose  north  pole  is  situated  at 
the  face  at  which  the  flux  leaves  the  loop.  The  small  arrows  in  the 
illustration  represent  the  magnetic  whorls  or  flux  surrounding  the  wire 
through  which  the  current  is  passing  in  the  direction  indicated  by  the 
large  arrows,  so  that  the  surface  of  the  loop  toward  the  observer  in  the 
diagram  has  north  polarity. 

The  Power  of  Electromagnets. — This,  in  electric  parlance,  varies 
with  the  number  of  ampere  turns.  In  other  words,  the  greater  the 
number  of  turns  of  wire  through  which  a  current  of  a  certain  number 
of  amperes  is  passing,  or  the  greater  the  number  of  amperes  passing 
through  a  wire  with  the  same  number  of  turns,  the  stronger  is  the 
induced  magnetism.  And  the  strongest  magnets  are  produced  by 
increasing  both  the  amperage  and  the  number  of  turns.  With  a  given 
source  of  electric  energy,  of  course,  there  is  a  maximum  strength  of 
magnetism  which  cannot  bo  exceeded.  .Making  the  number  of  turns 
greater  than  a  certain  number  would  introduce  such  an  additional 
resistance  as  to  reduce  the  number  of  amperes  to  an  equal  or  oven  greater 
extent.  The  greatest  efficiency  is  obtained  when  the  resistance  in  the 
coil  of  the  electromagnet  is  equal  to  all  the  remaining  resistance,  includ- 
ing 1  he  internal  resistance  of  the  battery.  When  only  one  voltaic  I'ell 
is  used,  this  maximum  efficiency  in  the  production  of  a  powerful  elec- 
tromagnet is  obtained  bv  having  a  number  of  strands  wound  together. 
Wit  h  a  series  but  1  erv  t  he  best  results  are  obtained  fr< >m  a  coil  consisting 
of  one  long  single  wire,  the  number  of  turns  being  regulated  by  the 
Voltage  of  the  battery.  The  amount  of  power  is  illu>lrated  by  the 
fact  that  a  horseshoe  magnet  made  from  a  cylinder  ten  inches  long  and 


AN  ill  sustain  a  weight  of  fi  >uri  eon  pounds  when  acted  upon  by  t  ho  c 
from  a  single  cell,  in  which  t  here  is  a  xinc  surface  of  onlv  '_' :  square  ii     •  > •- 
and  t  ho  electrolyte  is  a  t  himbleful  of  dilute  acid.      In  ai     tliov  n 
experiment    ;i    cannon    weighing    .">(). HIHI    pounds    has    been    magnet  i/ei] 


112  MEDICAL    ELECTRICITY    AND    ROXTCEX    RAYS 

by  ;i  current  of  1(1  amperes  passing  through  10  miles  of  wire,  making 
~)2.")0  Tunis  around  the  cannon.  This  equaled  1  10.200  ain])ere  turns. 
The  electromagnet  thus  produced  was  so  strong  that  a  string  of  iive 
caniii  >n-balls  weighing  LMO  pounds  a])iece  hung  suspended  from  the 
cannon  by  mutual  attraction  and  heavy  iron  s])ikes  remained  in  a 
horizontal  ]iosition  in  space.  The  latter  effect  was  produced  when  a 
soldier  stood  before  the  muxxle  "f  the  cannon  whh  the  iron  spikes  in 
front  nf  his  body.  The  spikes  assumed  the  direction  of  the  lines  of 
force,  and  were  held  pressed  against  the  soldier's  body  in  that  ]>osition 
by  the  enormously  powerful  attraction  of  this  gigantic  electromagnet. 
A  similar  <  >bservat  ion  may  he  made  any  time  the  .r-ray  coil  is  turned  on. 
if  a  piece  of  cardboard  is  held  vertically,  separating  pens  or  other  light 
steel  or  iron  bodies  from  contact  with  the  end  of  the  soft-iron  core  of  the 
coil.  The  pen-  will  remain  horizontal  in  the  air.  one  end  attracted 
toward  the  coil  and  the  other  end  repelled.  This  effect  is  not  peculiar 
to  electromagnets— any  type  of  magnet  will  produce  similar  effects. 
An  iron  <>r  steel  rod  brought  near  one  pole  of  a  magnet  undergoes  mag- 
netic induction;  the  opposite  kind  of  magnetism  is  generated  in  the 
nearest  end.  and  this  end  is  attracted  to  the  pole  of  the  magnet,  while 
the  oilier  end  of  the  rod  has  the  same  magnetic  polarity  induced  in  it 
as  that  of  the  neighboring  pole  of  the  magnet,  and  is.  therefore,  repelled 
by  it.  The  strongest  effect,  of  course,  is  produced  by  a  horseshoe 
mairnet  upon  a  rod  placed  across  its  two  poles.  The  end  of  the  armature 
in  contact  with  the  north  pole  of  the  horseshoe  magnet  has  south  pi  >larity 
induced  in  it  by  the  influence  of  both  poles,  that  kind  of  magnetism 
being  attracted  into  it  by  the  north  pole  and  repelled  into  it  by  the 
south  pole.  It.  therefore,  has  a  doubly  strong  attraction  for  the  north 
p.  >le  of  the  horseshoe  magnet.  A  similar  induction  of  double  strength 
occur-  at  the  end  of  the  armature  in  contact  with  the  south  pole  of  the 
horseshoe  magnet.  A  horseshoe  magnet  with  an  armature  across  its 
end-  will  sustain  more  t  iian  two  poles  of  a  bar  magnet  act  ing  separately. 
It  is  -aid  to  be  a  polarized  armature  when  the  armature  itself  is  a  per- 
manent magnet,  and.  of  course,  must  be  made  of  steel.  For  most 
purpose?  this  is  le--  desirable  than  an  armature  which  is  made  of  soft 
iron  and  lose-  it-  magnetization  when  not  under  the  influence  of  the 
magnet,  and  having  no  permanent  polarity  of  its  own.  re-ponds  fully 
and  freely  t<>  the  influence  of  the  magnet  in  every  position. 

<  iaiiot  ("'  Physics")  gives  the  following  as  the  results  of  different 
experiments  upon  electromagnetic  force,  and  these  have  varied  accord- 
ing TO  the  different  senses  attached  to  the  term  bv  various  observers. 
KlcPiromngnctic  force  may  mean  F  the  current  which  the  develop- 

the  magnetism  of  a  soft-iron  core  induce  in 
;  II  the  free  magnetism  measured  hvthe 
oscillating  at  a  distance:  <  III  \  he  nttnirt; ,-, 

r  the  force  required  to  hold  an  ai'inat  ure  at  a  disl  aiice  fn  mi  the 
nagnet :  (\\i  \\\u  lijti'iif]  /K///Y /•  measured  by  the  force  with  which 
at  ure  is  held  in  direct  contact  with  the  pole. 

os1    imp'irialU    results    \vhich    have    been    arrived    at    are    the 


tin 


DYNAMIC    ELECTRICITY  113 

there  is,   as  Miiller  has  found,   a   maximum  of  magnetization   which 
cannot  be  exceeded. 

(ii)  Taking  into  account  the  resistance,  the  electromagnetic  force  is 
independent  of  the  nature  and  thickness  of  the  wire.  Thus,  the  strength  of 
the  current  and  the  number  of  coils  being  the  same,  thick  and  thin 
wires  produce  the  same  effect. 

(iii)  With  the  same  current,  the  electromagnetic  force  is  independent 
of  the  width  of  the  coils,  provided  the  iron  projects  beyond  the  coils, 
and  the  diameter  of  the  coil  is  small  compared  with  its  length. 

(iv)  The  temporary  magnetic  moment  of  an  iron  bar  is,  within 
certain  limits,  proportional  to  the  number  of  windings.  The  product 
of  the  intensity  into  the  number  of  turns  is  usually  spoken  of  as  the 
magnetic  power  of  the  spiral.  The  greatest  magnetizing  power  is 
obtained  when  the  resistance  in  the  magnetizing  spiral  is  equal  to  the 
sum  of  the  other  resistances  in  the  circuit,  those  of  the  buttery  included, 
and  the  length  and  diameter  of  the  wire  must  be  so  arranged  as  to 
satisfy  these  conditions. 

(v)  The  magnetism  in  solid  and  in  hollow  cylinders  of  the  same 
diameters  is  the  same,  provided  in  the  latter  case  there  is  sufficient 
thickness  of  iron  for  the  development  of  the  magnetism.  With  currents 
below  a  certain  strength,  wide  tubes  of  sheet  iron  are  far  more  powerfully 
magnetized  than  solid  rods  of  the  same  length  and  weight;  but  with 
more  powerful  currents,  the  magnetism  of  the  latter  preponderates. 

(vi)  The  attraction  of  an  armature  by  an  electromagnet  is  pro- 
portional to  the  square  of  the  intensity  of  the  current  so  long  as  the 
magnetic  moment  does  not  attain  its  maximum.  Two  unequally  strong 
electromagnets  attract  each  other  with  a  force  proportional  to  the 
square  of  the  sum  of  both  currents. 

(vii)  For  powerful  currents  the  length  of  the  branches  of  an  electro- 
magnet is  without  influence  on  the  weight  which  it  can  support. 

Beetz  observed  that,  for  the  same  strength  of  current,  electro- 
magnetism  is  produced  more  rapidly  in  circuits  with  great  resistance 
and  great  electromotive  force  than  in  circuits  with  small  resistance 
and  correspondingly  smaller  electromotive  force:  in  the  latter  case,  the 
reverse  currents  which  occur  in  the  coils  of  the  electromagnet  come 
into  play  more  than  in  the  former. 

During  magnetization  the  volume  of  a  magnet  does  not  vary.  This 
has  been  established  by  placing  the  bar  to  be  magnetized  with  its  helix 
in  a  sort  of  irate r  thermometer,  consisting  of  a  flask  provided  with  a 
capillary  tube.  On  magnetization,  no  alteration  in  the  level  of  the 
water  is  observed.  But  the  dimensions  vary:  the  diameter  is  somewhat 
lessened,  and  the  length  increased:  according  to  Joule,  to  the  extent 
of  about  .,-,',,,,7]  if  the  bar  is  magnetized  to  saturation. 

As  regards  the  quality  of  the  iron  used  for  the  electromagnet,  it 
must  be  pure,  and  be  made  as  soft  as  possible  by  being  reheated  and 
cooled  a  great  many  times:  it  is  polished  by  means  of  a  file,  so  as  to  avoid 
twisting.  If  this  is  not  the  case,  the  bar  retains,  even  after  the  passage 
of  the  current,  a  quantity  of  magnetism  which  is  called  the  remanent 
magnetism.  A  bundle  of  soft-iron  wires  loses  its  magnetism  more 
rapidly  than  a  massive  bar  of  the  same  size.  According  to  Stone,  iron 
wires  may  be  materially  improved  for  electromagnetic  experiments  In- 
forming them  into  bundles  and  tying  them  round  with  wire:  these 
bundles  are  then  dipped  in  paraffin  which  is  set  fire  to. 
8 


114 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


"Remanent  magnetism  is  greater  in  long  magnets — those,  that  is  to 
say.  in  which  the  diameter  is  small  in  proportion  to  the  length.  It  is 
decidedly  greater  in  soft  iron  when  the  magnetizing  current  is  not 
opened  suddenly,  as  is  usually  the  case,  but  is.  gradually  brought  to 
zero  by  inserting  successively  greater  resistances.  By  suddenly  opening 
the  circuit  it  has  occasionally  been  found  with  thick  rods  of  very  soft 
iron  that  a  reversed  remanent  magnetism  is  met  with,  which  is  called 
abnormal  magnetization. 

"  This  is  easily  understood  from  the  tendency  of  molecular  magnets 
to  revert  to  their  primitive  condition.  In  doing  this  they  experience 
a  certain  friction  or  resistance,  and  when  the  magnetization  gradually 
diminishes,  this  hinders  the  complete  reversal  of  the  molecules:  but 
with  a  sudden  cessation  the  molecules,  from  the  greater  vis  viva  of 
their  reversal,  will  sooner  come  back  to  their  original  position,  or  even 
pass  it.  and  come  to  rest  on  the  opposite  side." 

Ampere's  Electric  Theory  of  Magnetism. — This  theory  is  that 
in  iron  or  steel  there  are  electric  currents  in  motion  around  the  atoms 
or  in  the  atoms,  and  that  when  these  currents  are  polarized  or  all  made 
to  flow  in  the  same  direction  the  iron  or  steel  becomes  a  magnet.  Except 
at  the  surface,  these  currents  are  supposed  to  neutralize  each  other. 
Fig.  91  illustrates  Ampere's  theory  of  magnetic  induction  by  an  electric 
current. 


Fit'.  91.— AnipfTf':-  tin 


>f  magnetism.     Klcctrio  Currents  about  the  atoms  oausrd  to 
itr-sunic  the  .-ami-  direction. 


Magnetic  Inertia  or  Reluctance. — An  expenditure  of  energy  is 
required  to  cau.-e  all  1  he  currents  theoretically  present  in  an  unmag- 
netized  bar  of  iron  or  steel  to  flow  in  the  same  direction  and  make  the 
bar  of  iron  a  magnet .  or.  on  the  other  hand,  to  reverse  the  polarity  ol  a 
magnet.  Both  of  the>e  processes  take  time,  and  so  does  the  return  ol 
a  soft-iron  electromagnet  to  the  unmagnetized  slate.  The  magnetic 
effect  is  not  instantlv  produced  when  the  electric  current  is  turned  on 
or  off.  but  there  is  a  certain  magnetic  inertia  or  reluctance  to  be  over- 

e.  This  is  of  no  consequence  in  the  case  of  an  electromagnet 
which  is  to  be  u.-ed  for  some  time  continuously  without  a  reversal  of 
polarity.  The  large  electromagnet  u>ed  for  the  extraction  ol  steel 
panicle-  from  the  eveball  i-  one  of  this  sort.  But  in  the  ca.-e  of  the 


DYNAMIC    ELECTRICITY  115 

electromagnet  which  forms  the  core  of  the  primary  coil  of  an  induction 
coil,  it  is  necessary  that  the  magnetic  inertia  should  be  reduced  to  the 
lowest  possible  amount,  so  as  to  enable  it  to  become  a  powerful  magnet 
the  moment  the  electric  current  is  turned  on,  and  then  completely  to 
lose  its  magnetism  the  moment  the  current  is  turned  off.  The  breaking 
of  the  circuit  may  be  accomplished  by  the  action  of  the  electromagnet 
itself  pulling  the  armature  away  from  contact,  or  it  may  be  done  by  some 
extraneous  means.  In  the  latter  case,  the  minimum  magnetic  inertia 
is  required  for  the  proper  induction  of  currents  in  the  secondary  by  the 
action  of  intermittent  currents  in  the  primary  coil.  The  minimum 
magnetic  inertia  is  obtained  by  making  the  soft-iron  core  a  bundle  of 
straight  parallel  wires;  and  for  an  x-ray  coil,  for  instance,  these  wires 
are  about  the  size  of  piano  wire,  and  form  a  bundle  two  or  three  inches 
in  diameter,  and  about  twice  as  long  as  the  spark-length  of  the  coil. 
Another  way  of  reducing  the  magnetic  inertia  is  by  making  the  electro- 
magnet of  many  thin  sheets  of  soft  iron  bound  together,  and  this  is 
designated  as  a  laminated  magnet.  The  powerful  magnets  of  electric 
motors  are  often  made  in  this  way. 

The  Properties  and  Effects  of  Magnetic  Flux. — Electromagnetic 
waves  in  the  universal  ether  are  what  this  flux  really  is.  They  have 
the  same  velocity  in  free  space  as  light,  and  are  subject  to  the  same 
variation  in  velocity  when  passing  through  different  media.  The 
index  of  refraction  of  a  substance  for  light  is  closely  related  to  its 
magnetic  permeability.  The  magnetic  flux  rotates  the  plane  of  polarized 
light  if  the  polarizing  substance  is  in  a  magnetic  field,  and  it  also  gives 
the  property  of  polarization  to  some  substances  which  do  not  ordinarily 
possess  it.  The  Hertzian  waves  used  in  wireless  telegraphy  are  elec- 
tromagnetic waves.  The  flux  from  a  magnet  has  the  power  to  produce 
magnetism  in  other  iron  or  steel  bodies  in  the  neighborhood,  without 
loss  of  its  own  power.  The  magnetic  flux  also  exerts  an  attraction  or 
repulsion  upon  such  bodies  and  upon  wires  through  which  a  current 
of  electricity  is  passing.  Variations  in  magnetic  flux  produce  currents 
of  electricity  in  wires  in  the  magnetic  field,  and  this  is  to-day  the  most 
important  source  of  electricity,  and  is  the  reason  why  it  has  been 
necessary  to  state  so  many  of  the  facts  in  regard  to  magnetism. 

A  coil  of  wire  placed  with  its  turns  in  a  horizontal  plane  and  open 
at  the  top  and  bottom,  and  traversed  by  a  current  of  electricity,  exerts 
an  attraction  upon  an  iron  bar  placed  within  its  lumen.  The  bar  may 
even  be  held  suspended  in  mid  air  by  the  invisible  attractive  force,  not 
being  in  contact  with  any  part  of  the  coil,  but  simply  inside  the  opening 
along  its  axis.  If  the  bar  is  pulled  a  little  distance  in  either  direction, 
the  attraction  will  bring  it  back  to  its  position  inside  the  coil.  The 
mutual  attraction  existing  between  electric  currents  and  magnets  is  the 
force  concerned  in  electric  motors  and  dynamos.  (See  also  p.  119.) 

The  Attraction  Between  Electric  Currents. — Two  active  loops 
of  wire  freely  suspended  tend  to  place  themselves  in  such  a  position 
that  their  plane  surfaces  are  parallel  with  each  other  and  the  cm-rents 
flow  in  the  same1  directions.  The  laws  governing  the  matter  are 
that — (1)  Two  currents,  parallel  and  in  the  same  direction,  attract  each 
other.  (2)  Two  currents,  parallel  but  in  opposite  directions,  repel  each 
other. 

The  north  pole  of  a  magnet  will  be  attracted  by  the  end  of  an  active 


IK! 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


helix  which  lias  south  polarity,  and  will  be  repelled  by  the  end  having 
north  polarity. 

In  the  case  of  either  the  iron  bar  or  the  magnet  being  fixed  and  the 
active  coil  (win1  through  which  an  electric  current  is  passing)  being 
freely  movable,  the  same  attraction  or  repulsion  will  be  operative  And 
this  will  cause  the  active  coil  to  move  into  such  position  that  the  rela- 
tions between  the  coil  and  the  magnet  or  iron  bar  are  the  same  as  if 
the  latter  had  been  movable  and  the  coil  stationary.  If  one  active  coil 
is  stationary  and  the  other  freely  movable,  the  latter  will  move  toward 
the  former  if  the  currents  are  both  in  the  same  direction,  or  away  from 
it  if  the  currents  are  in  contrary  directions. 

Production  of  Electric  Currents  from  Magnetism. — If  one  pole 
of  a  magnet  is  brought  near  a  coil  of  wire  which  is  not  connected  with 
any  battery  07-  other  source  of  electricity,  a  current  of  electricity  will  be 
generated  in  the  wire.  This  may  be  demonstrated  by  connecting 
the  two  ends  of  the  wire  with  the  terminals  of  a  galvanometer.  The 
arrangement  in  Fig.  92  illustrates  the  principle  involved.  The  magnet 
being  moved  Toward  and  into  the  lumen  of  the  coil,  a  current  of  elec- 
tricity will  flow  through  the  wire  and  be  indicated  by  the  galvanometer 
during  the  motion  of  the  magnet.  A  current  will  flow  in  the  opposite 
direction  while  the  magnet  is  being  withdrawn.  Xo  current  will  flow 
through  the  wire  while  the  magnet  is  stationary  either  near  to  or  far 
from  the  coil.  The  direction  of  the  current  through  the  coil  varies 
according  to  which  pole  of  the  magnet  is  near  the  coil  and  whether  it  is 
being  moved  toward  or  away  from  the  coil.  The  arrows  in  Fig.  92 
indicate  the  direction  of  the  motion  of  the  magnet  and  also  of  the 


current:  and  the  letter-  X  and  S  indicate  the  north  and  south  poles  of 
the  magnet.  |o  represent  the  effect  of  withdrawing  the  magnet,  it 
would  simply  !«•  necessary  to  reverse  the  posuion  of  all  the  arrows 
representing  the  direction  jn  \\-hich  the  magnet  moves  and  the  current 
flows.  I'ig.  9)j  shown  the  direction  of  the  current  produced  when  the 
north  pole  of  a  magnet  is  moved  toward  a  coil.  And  in  this  case  also 
the  direction  of  the  current  is  reversed  if  the  magnet  is  moved  away 
IT'  MM  instead  "f  1<  iwan  i  1  he  n  >il. 

An  electric  current  is  produced  at  the  same  moment  and  in  the 
Same  direction  i;  the  pole  of  the  magnet  is  moved  luterallv  across  the 
face  or  end  of  the  coil  instead  of  into  it.  The  current  will  be  in  the 
direction  indicated  in  the  la-t  diagram  'Fig.  9:]i.  while  the  north  pole 
i-  moving  toward  the  axi>  of  the  coil  or  the  central  line  passing  through 


DYNAMIC    ELECTRICITY 


117 


the  hollow  of  the  coil  at  a  right  angle  to  the  planes  of  its  various  loops. 
After  the  pole  of  the  magnet  has  moved  past  the  axis  of  the  coil  and 
begins  to  move  away  from  it,  an  electric  current  in  the  opposite  direc- 
tion is  generated  in  the  coil.  The  currents  produced  by  moving  the 
south  pole  of  the  magnet  laterally  across  the  face  of  the  coil  are  the 


Fig.  93. — Direction  of  the  current  when  the  north  end  of  the  magnet  is  moved  toward  the 

coil  of  wire. 

same  as  those  produced  by  moving  the  same  pole  into  or  out  of  the 
coil,  as  shown  in  Fig.  93. 

Magneto-electric  Machines. — The  same  currents  are  generated 
in  all  these  cases  if  the  coil  is  moved  instead  of  the  magnet,  as  is  the 
arrangement  in  the  magneto-electric  machines  (Figs.  94,  95,  and  9(i) 
which  were  the  predecessors  of  the  modern  dynamos  and  which  are  still 
used  in  therapeutics  to  some  extent.  Taking  into  consideration  only 
one  of  the  coils  of  win',  as  that  is  rotated  toward  the  north  pole  of  the 
magnet,  a  current  will  be  generated  in  that  coil  which  will  be  in  the 
direction  of  the  hands  of  a  clock  if  the  coil  is  viewed  from  the  end  facing 
the  magnet.  At  the  same  time  that  this  coil  has  a  rotary  motion  toward 


Fig.  04. — Magneto-electric  machine  f<>r  therapeutic  use. 

the  north  pole  it  is  moving  away  from  the  south  pole  of  the  mag- 
net, and  the  electric  current  resulting  from  this  is  in  the  same1  direction. 
After  this  coil  passes  the  horizontal  line,  however,  it  begins  to  move 
away  from  the  north  pole  and  toward  the  south  pole,  and  the  direction 
of  the  current  flow  is  reversed,  so  that  a  regular  alternating  current  is 
generated  and  may  be  transmit  tod  to  a  circuit  outside  of  the  machine 
by  having  the  two  extremities  of  the  wire  connected  with  two  insulated 
revolving  metal  collars,  against  which  press  two  springs  or  bn:>hes 
conducting  the  current  to  the  external  circuit.  The  other  coil  i-  re- 
ceding from  the  north  pole  of  th'-  magnet  at  the  time  that  the  one 


118 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


first  considered  is  approaching  it,  and  consequently  it  is  necessary  that 
its  wire  should  !«'  wound  in  the  opposite  way  to  make  it  yield  currents 

in  the  same  direction  as  those  from 
the  first  coil.  The  coils  are  both  con- 
nected with  the  external  circuit  by 
the  same  metallic  collars  and  brushes, 
and  reinforce  each  other  in  delivering 
an  alternating  current. 


Fig.  95.  — Clark's  magneto-electric  Ren- 
orator,  1500  turns  in  cadi  coil  rotated  in 
front  of  magnet  (laminated). 


Fig.  96. — Rotated  so  as  to  cause  upper 
portion  to  come  toward  observer,  current 
would  go  as  shown  by  arrows.  After  a  half 
turn  it  would  be  reversed. 


The  Commutator. — This  is  an  important  part  of  any  machine  for 
the  generation  of  dynamic  electricity  by  electromagnetic  induction. 
It  is  a  device  for  converting  a  series  of  alternating  currents  into  a  series 
of  unidirectional  currents  passing  into  the  external  circuit.  In  its 
simplest  form  (Fig.  97  and  98)  it  consists  in  having  the  wires  from  the 
coils  terminate  in  the  two  halves  of  a  metal 
cylinder  which  is  completely  divided  into 
two  longitudinal  halves,  fastened  upon  an 
insulated  shaft  and  rotating  with  the  coils. 
Each  brush  leading  to  the  external  circuit 


Fig.  97.  — Commutator. 


Fig.  9X.  —  Diagram  of  the  commutator  in 
operation. 


is  in  contact  with  one  of  the  halves  of  the  split  cylinder  and  receives 
current  from  it.  Calling  the  sections  of  the  commutator  <i  and  h,  and 
the  brushes  1  and  2,  the  adjustment  should  be  such  that  during  the 
half  revolution  that  commutator  section  <i  is  positive  it  should  be  in 
cnntact  with  brush  1.  and  when  it  becomes  negative,  the  connection 
changes  to  brush  '2.  The  division  between  the  two  halves  of  the 
commutator  is  to  be  at  such  a  point  that  the  connection  with  the  two 
brushes  changes  at  the  same  time  thai  the  polarity  in  the  coils  changes. 
While  the  current  in  t  he  coils  -is  in  one  direction,  n  is  the  posit  ive  com- 
mutator section  and  is  connected  with  brush  1.  and  while  the  current 
is  in  the  opposite  direction,  h  is  the  positive  commutator  section  and 


DYNAMIC    ELECTRICITY  119 

this  is  then  connected  with  brush  1.  As  each  alternate  current  is 
generated  in  the  coil  it  is  passed  through  the  commutator  and  brushes 
in  sucli  a  way  as  always  to  traverse  the  external  circuit  in  the  same 
direction. 

Magnetic  Lines  of  Force  or  Magnetic  Flux. — If  a  bar  magnet 
is  placed  flat  upon  a  table  and  a  sheet  of  paper  sprinkled  with  iron  filings 
is  laid  over  it,  the  iron  filings  will  assume  positions  corresponding  to  the 
magnetic  lines  of  force1.  Near  the  two  poles  the  particles  will  be  most 
abundantly  massed,  and  will  radiate  in  every  direction,  while  near  the 
middle  of  the  bar  there  will  be  few  particles,  and  these  will  be  more  or 
less  parallel  with  the  long  axis  of  the  magnet.  The  arrangement  of  the 
particles  of  iron  corresponds  with  the  lines  of  force.  These  are  supposed 
to  be  due  to  ether  streamings,  both  in  the  magnet  and  outside  of  it, 
set  up  by.  the  molecular  forces  at  work  in  the  magnet.  The  lines  of 
force  or  the  magnetic  flux  leave  the  magnet  at  its  north  pole  and  enter 
at  its  south  pole.  Of  course,  it  is  not  limited  to  the  plane  of  the  paper, 
as  is  apparently  the  case  in  the  above  experiment,  but  really  com- 
pletely surrounds  the  magnet  in  every  direction.  This  can  be  seen  at 
once  if  the  magnet  is  dipped  into  a  mass  of  loose  iron  filings.  And  the 
direction  of  the  lines  of  force  in  the  surrounding  space  can  be  shown 
by  using  fine  sewing-needles  in  the  place  of  the  iron  filings  in  the  last 
experiment.  (See  also  p.  115.) 

The  direction  of  the  lines  of  force  is  subject  to  change  under  the 
influence  of  magnetism  or  electricity.  For  instance,  if  two  similar 
magnetic  poles,  like  the  north  poles  of  two  magnets,  are  brought  near 
together,  the  lines  of  force  from  each  are  made  to  diverge  more  widely 
than  if  one  magnet  had  been  there  alone.  And,  on  the  other  hand, 
the  lines  of  force  of  both  arc  made  to  converge  and  pass  from  one  magnet 
to  the  other,  forming  an  ellipsoid  if  two  opposite  magnetic  poles  are 
brought  near  together.  The  attraction  of  a  magnet  for  other  iron  or 
steel  bodies  is  dependent  upon  the  number  of  lines  of  force  that  reach 
the  body  to  be  attracted,  and  there  are  two  special  cases  which  are  to  be 
considered  in  the  construction  of  elcctrotherapeutic  apparatus.  In  one 
class  of  cases  the  desire  is  to  produce  an  attraction  upon  an  iron  or  steel 
body  at  some  distance  from  it,  regardless  of  how  many  lines  of  force 
may  be  wastefully  expended  in  the  surrounding  space.  Such  case* 
are  that  of  the  electromagnet  for  extracting  foreign  bodies  from  the 
eye,  and  of  the  electromagnets  used  in  the  vibrating  interrupter  for 
the  primary  currents  in  induction  coils.  For  this  purpose  magnets 
are  made  of  the  aeroferric  type.  This  means  that  the  flux  passes  from 
one  pole  to  the  other  partly  through  air  and  partly  through  iron,  and 
the  electromagnet  is  generally  made  in  the  shape  of  a  straight  bar  or 
bundle  of  wires  surrounded  by  a  coil  of  wire  through  which  an  electric 
current  is  flowing,  and  the  polar  extremity  may  even  be  conic.  Leakage 
flux  is  the  technical  designation  for  lines  of  force  which  do  not  pass 
through  the  armature. 

To  secure  the  greatest  holding  power,  however,  the  ferric  t>jpe  is 
required,  which  means  that  the  magnetic  flux  or  lines  of  force  passing 
out  of  the  magnet  at  the  north  pole  traverse  only  iron  on  their  way  to 
the  south  pole.  This  is  accomplished  in  certain  cases  by  making  the 
magnet  in  the  form  of  a  horseshoe,  and  placing  an  armature  across 
between  the  two  poles.  The  horseshoe  shape  may  lie  only  figurative, 
as  in  the  case  of  a  very  useful  type  of  electric  motor  (Fig.  99 1.  where 


120 


MKDK'AL    ELECTRICITY    AND    RONTGEN    RAYS 


there  is  a  heavy  iron  base'  from  which  two  uprights  extend;  the  latter 
have  large  concave  surface's  facing  each  other,  and  called  polar  surfaces. 
Between  the  polar  surfaces  and  very  close  to  them  is  the  revolving  arma- 
ture of  the  motor.  The1  stationary  part  is  made  a  powerful  magnet  by 
an  electric  current  passing  through  coils  of  wire  surrounding  each  iron 
standard.  It  will  be  noted  that  it  is  not  necessary  that  the  polar 
surfaces  should  be  at  the  ends  of  the  arms  of  the  horseshoe.  Kxcept 
for  the  small  air-space  between  the  polar  surfaces  and  the  armature, 
the  magnet  represented  above  is  of  the  ferric  type.  One  of  the  absolute 
ferric  type  is  a  horseshoe  magnet  with  an  iron  armature  across  its  ends, 
and  another  is  an  iron  ring  magnetized  by  an  electric  current  passing 
through  a  coil  of  wire  which  surrounds  the  wire  at  one  part  of  its  cir- 
cumference. The  first  of  these  types  of  complete  ferric  magnets  is 
often  adopted  as  a  means  of  guarding  against  the  gradual  weakening 
of  a  permanent  magnet  and,  of  course,  is  the  case  where  an  electro- 
magnet is  used  to  lift  or  to  sustain  a  heavy  weight.  The  second  or 
closed  magnetic  ring  forms  part  of  the  step-up  transformer  for  the 


induction  of  high-tension  currents  in  a  secondary  winding  by  alternating 
or  interrupted  currents  in  a  primary  wire;  or  of  the  step-down  trans- 
former, which  induces  currents  of  reduced  potential  in  the  secondarv 
wire.  For  this  purpose  again  the  closed  magnetic  ring  may  be  only 
figuratively  a  rim:.  Very  often  it  is  made  up  of  laminated  rectangles 
of  soft  iron,  riveted  toget  her  at  i  he  corner.--  and  surrounding  a  rectangular 
opening.  'Ihe  closed  magnetic  ring  has  a  verv  much  higher  rate  of 
efficiency  in  tin-  production  of  induced,  currents  than  has  the  other 
type  of  induction  i-nil  with  a  straight  iron  core. 

Mill/in  in-  jli/.r  is  i  hr>  force  bv  which  steel  and  iron  are  attracted 
toward  magnets,  and  by  which  electric  currents  are  generated  from  the 
use  of  maLMiet^.  It  is  proportional  to  the  magnetomotive  force,  and 
inverselv  to  the  magnetic  resistance  of  the  circuit  (ferric,  aeroterric, 
or  non-ferric)  or  the  magnetic  reluctance.  The  practical  unit  of 
magnetic  flux  is  the  //•</»/•;  of  reluctance,  the  airbed;  and  ol  magneto- 
motive force,  the  t/ilhi  /7.  The  formula  is  webers  ,  or  the  mini- 


DYNAMIC    ELECTRICITY  121 

her  of  units  of  magnetic  flux  is  equal  to  the  nuniher  of  magnetomotive 
units  divided  hy  the  nuniher  of  units  of  magnetic  reluctance.  An 
ampere-turn  or  a  current  of  one  ampere  through  a  single  loop  produces 
a  magnetomotive  force  of  ahout  1.25  gilherts.  The  magnetic  flux  is 
strongest  when  an  armature  connects  the  two  poles  or  when  the  magnet 
consists  of  a  closed  ring,  partly  hecause  of  tin;  fact  that  in  either  case 
the  magnetic  reluctance  is  reduced  to  the  lowest  possihle  amount. 

A  soft-iron  core  or  a  closed  magnetic  ring  adds  to  the  efficiency  of 
a  coil  in  producing  induced  currents,  hecause  it  adds  its  own  magnetic 
flux  to  that  directly  due  to  the  passage  of  the  current  through  the 
primary  coil. 

The  tncaxtircnient  of  tnaynctic  flux  is  done  hy  means  of  a  magnetic 
needle.  If  the  latter  is  moved  out  of  the  line  which  it  assumes  under 
the  influence  of  a  magnet  and  then  is  released,  it  will  oscillate  hack  and 
forth  before  finally  stopping  at  its  position  of  rest.  The  strength  of 
the  magnetic  pole  is  proportional  to  the  square  of  the  number  of  times 
that  the  magnetic  needle  swings  back  and  forth. 

Paramagnetic  and  Diamagnetic  Substances. — All  bodies,  solid, 
liquid,  or  gaseous,  are  influenced  by  magnetic  attraction.  If  certain 
substances,  like  iron,  steel,  nickel,  cobalt,  manganese,  or  oxygen  gas, 
are  suspended  between  two  opposite  poles  of  an  electromagnet,  they 
tend  to  arrange  themselves  in  the  line  between  the  two  poles,  and  are 
called  paramagnetic  substances.  Others,  like  bismuth,  phosphorus, 
zinc,  gold,  water,  or  hydrogen  g;us,  tend  to  arrange  themselves  at  a 
right  angle  to  the  line  passing  between  the  two  magnetic  poles,  and  are 
called  diamagnetic  substances. 

A  bar  of  cobalt  arranges  itself  so  that  its  length  is  parallel  with  the 
lines  of  force,  because  it  is  more  permeable  to  magnetic  flux  than  the 
surrounding  air.  and  nature  always  seeks  the  path  of  least  resistance. 
It  is  not  because  of  any  north  and  south  polarity  on  the  part  of  the  bar 
of  cobalt. 

A  bar  of  some  diamagnetic  substance  like  gold  arranges  itself  at  a 
right  angle  to  the  lines  of  force,  because1  it  is  less  permeable  than  the 
surrounding  air.  and  the  least  resistance  is  produced  when  the  gold 
forms  the  smallest  and  the  air  the  largest  possible  part  of  the  path 
traversed  by  the  magnetic  flux. 

Xo  substance  is  opaque  to  magnetic  flux.  The  flame  of  a  candle 
is  diamagnetic.  and  if  held  between  -the  1  \vo  poles  of  a  magnet,  it  is 
blown  out  at  a  right  angle  to  the  line  between  the  poles. 

In  turning  off  a  heavy  current  a  voltaic  arc  Avil'  sometimes  pass 
across  between  the  two  terminals,  and  unless  this  is  promptly  checked, 
the  apparatus  may  be  destroyed  or  the  building  set  on  fire.  In  situa- 
tions where  this  is  liable  to  happen  a  blower  is  placed.  This  is  a  powerful 
electromagnet,  the  flux  from  which  actually  blows  out  the  arc  passing 
between  the  two  terminals.  This  is  on  quite  a  different  principle  from 
that  of  the  circuit  breaker,  which  is  an  electromagnet  which  becomes 
operative  when  any  excessive  or  dangerous  current  is  flowing,  and 
shuts  off  the  current  bv  drawing  its  armature  away  tnuii  a  terminal. 
where  it  normally  completes  the  circuit.  The  two  devices,  however, 
are  sometimes  used  together. 


122  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

LIST  OK  PARAMAGXKTK1  AND  DIAMAGXKTIC  BODIES. 

Paramagnetic.  Diumaijnetic. 

Iron.  Bismuth. 

Xiekel.  Phosphorus. 

Cobalt.  Antimony. 

Aluminum.  Zinc. 

Manganese.  Mercury. 

Chromium.  Lead. 

(Vrium.  Silver. 

Titanium.  Copper. 

Platinum  (Wiedemann  found  pure  plati-       Gold. 

mini  diamagnetic!.  Water. 

Many  ores  and  salts  containing  the  above      Alcohol. 

metals.  Tellurium. 

Oxygen  gas.  Selenium. 

Sulphur. 
Thallium. 
Hydrogen  gas. 
Air. 

The  Influence  of  an  Iron  Core  in  a.  Magneto-electric  Machine. — In 

the  apparatus  illustrated  in  Fig.  05,  p.  118,  each  coil  has  a  core  of 
soft-iron  wires.  The  core  has  a  very  powerful  effect  in  increasing  the 
amount  of  current  induced  in  the  coil.  As  one  end  of  the  iron  core  is 
brought  near  the  positive  pole  of  the  magnet  it  becomes  magnetized 
itself,  and  that  end  becomes  the  negative  pole.  It  has  been  demon- 
strated in  many  different  ways  that  when  an  iron  core  inside  a  coil 
becomes  a  magnet,  it  generates  a  momentary  current  in  the  coil,  and 
another  momentary  current  in  the  opposite  direction  when  it  ceases 
to  be  a  magnet.  If  it  is  a  permanent  magnet,  but  varies  in  power  under 
any  influence,  then,  as  it  increases  in  power,  it  induces  a  current  in  the 
coil,  and  as  it  diminishes  in  power  it  induces  a  current  in  the  opposite 
direction  in  the  coil. 

A  soft-iron  core  always  has  some  effect  in  retarding  the  change  in 
the  polarity  of  the  coil  from  one  phase  to  another.  Its  magnetic  inertia 
makes  its  changes  in  polarity  approach  considerably  less  nearly  to  the 
instantaneous  than  would  the  changes  in  the  coil  alone. 

The  core  adds  very  much  to  the  amount  of  inverse  discharge  in  a 
coil,  but  this  is  a  subject  which  need  not  be  discussed  until  the  subject 
of  induction  coils  is  taken  up. 

Generation  of  Electric  Currents  in  a  Coil  of  Wire  when  it  Cuts 
Moving  or  Expanding  or  Contracting  Lines  of  Force. — The  motion 
by  which  the  coil  is  made  to  cut  the  lines  of  force  may  be  a  movement 
of  the  coil  of  wire  or  of  the  magnet.  The  same  change  in  their  relative1 
position  produces  the  same  electric  current  in  the  coil.  There  are 
manv  different  ways  in  which  the  details  of  this  may  be  varied. 

Lmz'*  Lnu\  In  any  case  of  elect rodynamic  induction  the  direction 
of  the  electric  current  produced  is  such  as  will  tend  to  oppose  the  motion 
producing  it.  The  value  of  the  knowledge  of  this  law  is  twofold.  It 
enables  one  to  calculate  the  direction  of  the  current  and  to  construct 
apparatus  consisting  of  several  different  magnets,  and  armatures  (coils 
with  or  without  cores)  and  commutators  and  brushes,  so  as  to  obtain 
a  combined  harmonious  effect  in  the  shape  of  either  an  alternating  or  a 
"direct"  current,  as  may  be  desired.  And.  in  the  second  place,  it 
brings  us  to  the  explanation  of  tin;  transformation  of  mechanic  into 


DYNAMIC    ELECTRICITY  123 

electric  power  in  the  simple  apparatus  in  Fig.  06,  \,.  118,  and  in  the 
more  complicated  dynamos.  In  any  of  these  machines  the  mechanic 
power  has  to  overcome  two  elements  of  resistance,  one  being  that  of 
inertia  and  friction  and  the  other  due  to  the  current  induced  in  the  coils 
of  wire.  The  power  which  is  used  up  in  overcoming  friction  is  con- 
verted into  heat.  According  to  Lenz's  law,  the  current  at  any  moment 
when  the  coil  is  approaching  a  magnetic  pole  is  such  as  will'  cause;  a 
force  of  repulsion  between  the  coil  and  the  magnet.  The  force  required 
to  move  the  coil  through  space  against  this  repulsion  disappears  as 
mechanic  power  to  be  converted  into  electric  power.  And  the  like 
condition  occurs  when  a  coil  is  being  moved  away  from  a  magnetic 
pole:  the  current  induced  is  such  as  to  attract  the  coil  toward  the 
magnet,  and  the  power  exerted  in  overcoming  this  attraction  and 
moving  the  coil  away  disappears  as  mechanic  power  and  is  converted 
into  electric  power. 

The  Mechanic  Equivalent  of  Electricity. — Just  as  the  mechanic 
equivalent  of  heat  may  be  expressed  as:  1  pound  of  water  1°  F.  =  778 
foot-pounds,  or  it  takes  778  foot-pounds  of  work  to  raise  1  pound  of 
water  1°  F.;  the  mechanic  equivalent  of  electricity  is  1  watt  =  T}^ 
horse-power,  or  1  kilowatt  (1000  watts)  =  1.34  horse-power.  The 
number  of  watts  produced  by  a  dynamo  is  found  by  multiplying  the 
number  of  amperes  by  the  number  of  volts.  In  a  well-constructed 
dynamo  of  large  size  about  90  per  cent,  of  the  horse-power  exerted  by 
the  steam  engine  in  running  it  will  reappear  as  electric  energy  at  the 
ratio  of  1.34  horse-power  per  kilowatt.  In  electric  motors  the  process 
is  reversed,  and  in  large  motors  perhaps  98  per  cent.,  the  electric  energy 
passing  through  the  motor  as  so  many  amperes  at  a  pressure  of  so  many 
volts  is  converted  into  mechanic  power  at  the  ratio  of  1  kilowatt  =  1.34 
horse-power.  Small  motors  are  much  less  efficient,  a  fractional  horse- 
power motor  utilizing  only  30  per  cent.,  the  rest  being  lost  in  friction 
and  other  ways. 

THE  DYNAMO 

The  name  covers  a  variety  of  machines  for  the  conversion  of  mechanic 
motion  into  currents  of  electricity  by  means  of  electromagnetic  induc- 
tion. 

The  essential  parts  are  field  magnets,  armatures,  commutators, 
and  brushes.  The  field  magnets  may  be  stationary,  and  the  armatures 
made  to  move  past  them,  or  the  armatures  may  be  stationary  and  the 
field  magnets  movable. 

The  field  magnets  are  electromagnets  or  masses  of  iron  or  steel 
surrounded  by  coils  of  wins  and  which  are  to  a  certain  extent  permanent 
magnets,  or,  at  all  events,  retain  a  sufficient  amount  of  residual  mag- 
netism to  induct1  an  electric  current  when  the  machinery  is  started. 
There  is  then  an  arrangement  by  which  the  whole  or  a  part  of  the 
current  so  produced  is  made  to  pass  through  the  winding  of  the  field 
magnets,  and  they  soon  become  exceedingly  powerful. 

The  armatures  are  essentially  coils  of  wins  usually  with  soft-iron 
cores,  which  are  made  to  cut  the  lines  of  force  from  the  field  magnets 
by  their  own  motion  or  that  of  the  field  magnets,  as  the  case  may  be. 
An  alternating  current  is  generated  in  each  armature  coil,  and  passes 
through  the  commutator,  .which  mav  or  mav  not  convert  them  into 


124 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


direct    (/.   c.,   unidirectional)    currents   before   they   reach   the   brushes 
from  which  they  pass  to  the  field  magnets  and  the  external  circuit. 

'The  commutator,  whose  function  has  been  explained  on  p.  118,  is 
made  of  rectangular  bars  of  copper  surrounding  and  forming  part  of  the 
revolving  axle  in  which  they  are  set  in  insulated  slots.  Kaeh  commu- 
tator section  is  a  direct  continuation  of  the  wire  from  one  end  of  the 
corresponding  armature  coil,  and  really  forms  the  termination  of  it. 
There  is  no  further  path  for  the  current  until  that  commutator  section 
comes  in  contact  with  one  of  the  brushes.  At  that  time  the  commu- 
tator section  connected  with  the  other  end  of  the  same  armature  coil  is  in 
contact  with  the  other  brush.  And  then  the  cutting  of  this  armature 
coil  through  the  lines  of  force  of  the  field  magnets  induces  a  current 
which  passes  through  the  armature  coil,  the  commutator,  one  brush, 
the  external  circuit,  and  the  winding  of  the  field  magnet,  the  other  brush, 
the  other  commutator  section,  and  the  same  armature  coil.  The  output 
of  a  dynamo  is  a  rapid  succession  of  such  currents  which  may  pass 
through  the  external  circuit  in  the  same  or  alternating  direction, 
according  to  the  construction  of  the  commutator. 

The  commutator  section-  are  bare  upon  their  external  surface,  so 
as  tn  be  exposed  to  complete  electric  contact  with  the  brushes  at  the 
proper  time.  They  are  inlaid  in  hard  rubber  or  indurated  fiber,  or 
in  <ome  small  machines  in  ivory,  which  insulates  them  from  each  other 
and  from  the  steel  axle  of  the  dynamo. 

The  brushes  are  in  direct  connection  with  the  two  terminals  of  the 
dvnamo.  and  are  analogous  in  function  to  the  collecting  combs  of  a 
-tatic  machine,  leading  the  positive  and  negative  charges  to  the  two 

poles    of    the    machine.       They 

+  <S*PF>V  ,.„«,;,  sometimes    consist    of   flat    brass 

springs  which  press  upon  the 
commutators  and  come  in  con- 
tact with  the  different  commu- 
tator sections  and  the  insulating 
strips  as  the  axle  revolves.  In 
large  dynamos  the  brushes  are 
rectangular  pieces  of  carbon  or 
brass  held  against  the  revolving 
commutator  by  the  pressure  of  a 
spring. 

Series-wound  and  Shunt-wound  Dynamos.— A  dynamo  in  which 
the  entire  cm-rent  induced  in  the  armature  coils  passes  through  the 
winding  of  the  field-magnets  is  called  a  series-wound  cli/tKinio  (Fig.  100), 
and  thi-  arrangement  tends  to  maintain  a  uniform  strength  of  current, 
or  the  >ame  number  of  amperes,  no  matter  how  great  or  how  small  is 
the  resistance  in  the  external  circuit.  This  sort  of  a  dynamo  is  used 
when  the  current  is  produced  expressly  for  the  operation  of  a  number 
of  arc  liu'hts  connected  up  in  series.  The  number  of  amperes  which 
nnM  pass  through  each  arc  light  is  from  (i  to  10.  The  re.-islance  of 
;iii  arc  lump  is  -uch  that  it  takes  12  to  .72  volts  potential  to  send  this 
current  iliroiiirh  one  lamp.  For  a  number  of  arc  lamps  in  series  the 
voltage  HUM  be  multiplied  by  the  same  number,  in  order  to  send  the 
-ame  -trenii'th  of  current  through  the  series  of  lamps.  This  is  accom- 
plished automatically  by  a  series-wound  dynamo.  A  series-wound 


DYNAMIC    ELECTRICITY 


125 


elynamo  may  bo  calleel  a  constant  current  dynamo.  This  is  true1  up  to 
the1  capacity  of  the1  engine  in  horse-power.  Beyonel  that  the  elynamo 
woulel  fail  to  drive  any  current  through  a  scries  of  are-  lamps.  A  xlmnt- 
iroiind  dynamo  (Fig.  101)  is  called  a  constant  potential  dynamo,  and  is 
elosigned  to  yie'lel  a  current  of  the  same1  voltage  uneleT  varying  e-eniditions 
of  the  external  circuit.  In  such  a 
elynamo  the  winding  of  the  hVlel- 
magnets  consists  of  a  groat  many 
turns  of  fine1  wire  having  a  resist- 
ance about  four  hundred  time's  as 
gr(>at  as  that  of  the1  armature  coils. 
Starting  from  the  positive1  brush, 
the1  cunvnt  passes  through  a  eliviele'el 
path,  erne1  part  ge>ing  to  the  external 
circuit  and  the1  other  to  the  wineling 


I'ifl.  101.  —  Shunt-wound  dynamo:  / 
Rheostat  rejrulates  proportion  of  the  t  \v< 
current  paths. 


of  the  field-magnets.  The  return 
currents  from  the  field-magnets  and 
the  external  circuit  join  before  they 
reach  the  negative  brush.  The  currents  which  pass  through  the  two  dif- 
ferent paths  are  inversely  proportional  to  the  resistance  in  each.  If  the 
external  resistance  is  increased,  a  greater  proportion  of  the  current 
passes  through  the  field-magnets,  and  this  increases  their  strength  and 
the  current  output  of  the  dynamo.  The  reverse1  takes  place  when  the 
external  resistance  is  diminished.  The  result  is  a  uniform  voltage  under 
most  conditions. 

Compound-wound  Dynamos. — These  are  dynamos  in  which  part 
of  the  current  to  the  external  circuit  passes  through  the  field-magnets 
and  a  portion  does  not.  They  are  designed  to  yield  a  uniform  voltage 
under  all  conditions  from  no  load  to  full  load.  The  10,000  horse-power 
dynamos  at  Niagara  Falls  are  of  this  type. 

In  any  dynamo  the  electromotive  force  or  voltage  increases  with  the 
speed,  the  strength  of  the  field-magnets,  and  the  number  of  conducting 
loops  in  the  armature. 

Gramme's  Ring  Dynamo. — This  is  an  important  typo  of  dynamo, 
in  which  a  soft-iron  ring  revolves  like  a  wheel  on  its  axle,  its  rim  being 
close  to  the  two  poles  of  an  electromagnet  concaved  so  as  to  bring  the 
polar  surface's  as  ne>ar  as  possible  to  the  ring.  The  latteT  has  a  winellng 
of  many  turns  e)f  insulated  wire,  making  an  ewlle-ss  coil  around  the1  rim 
of  the'  wheel.  The1  ring  being  rotated  in  the  direction  indicated  by  the 
arrows  at  the1  axle  in  Fig.  102,  oloe'trie-  e-unvnts  will  flow  through  the 
armature1  in  the  direction  shewn  by  the1  small  arrows.  Commutator 
sections  are1  arranged  to  connee-t  with  the1  armature1  at  the1  points  midway 
between  the  pole's  e>f  the  magne't,  and  the  erne1  markeel  -f-  is  the  positive1 
pole,  and  the  one1  marke-d  —  is  the1  negative*  pole1  of  the1  dynamo.  The1 
current  is  "direct,"  and  is  almost  e-ontinuems.  As  actually  constructed 
for  use  as  a  hand  gcneTator  of  oleM-trie-ity  (Fig.  103)  th(>  magnet  is  a 
powerful  one  of  horseshoe  shape1,  and  made1  of  laminated  stevl.  The 
armature  consists  of  thirty  e-oils,  eae-h  having  a  large1  number  of  turns 
of  line'  wire.  One  end  erf  each  coil  is  connected  with  the1  aeljacenit  e'nd 
of  the  ne'xt  e'oil,  and  also  with  a  e-ommutator  section.  The1  coils  thu- 
f'orm  a  continuous  e-ircuit,  tappexl  at  intervals  by  the1  commutator 
-ections.  The1  armatun1  core1  is  made  up  of  a  number  erf  soft-iron 
wires  forming  a  continuous  ring.  A  hand  machine  of  this  kind  vields 


126 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


a  potential  of  about  three  or  four  volts,  which  is  about  the  same  as  is 
yielded  by  three  or  four  Dauiell  cells.     The  current  is  a  strong  one,  and  a 

hand  machine  could  be  used  for  cau- 
tery purposes  or  for  exciting  a  faradie 
coil.  But  for  most  electrotherapeutic 
work  the  choice  lies  between  a  battery . 
either  primary  or  secondary  (storage), 
and  a  power-driven  dynamo. 


m.    1()L'.  • --( iramme's    rin<r    armature    in 
Im.ohir  field. 


Fig.  103. — Gramme's  rinjz  dynamo. 


A  Dynamo  Suitable  for  a.  Separate  x-Ray  and  Electrotherapeutic 

Installation.-   The  apparatus  shown   in  Fig.    104   is  a  dynamo  driven 
by   a    gas-engine;   both   operating  upon  the   same   shaft   and   forming 


DYNAMIC    ELECTRICITY 


127 


a  single  machine.  The  dynamo  itself  may  be  independent  and  operated 
by  a  steam  or  gas-engine  or  by  water  power.  A  two  and  one-half 
kilowatt  dynamo  requires  four  or  five;  horse-power  to  run  it,  and  yields 
a  current  of  20  amperes  and  125  volts.  The  dynamo  itself  measures 
about  30  inches  in  all  three  dimensions,  weighs  about  550  pounds,  and 
makes  about  1150  revolutions  a  minute.  This  dynamo  is  designed  to 
yield  a  direct  current  of  the  above  amperage  and  voltage,  but  dynamos 
are  made  to  yield  various  other  strengths,  and  an  alternating  current 
if  desired. 

Motor  Generators. — When  the  current  from  a  dynamo  can  be 
obtained,  but  is  not  of  the  required  character,  it  may  be  made  to  run  an 
electric  motor  which  in  turn  produces  the  rotation  .of  a  dynamo  and  the 
consequent  evolution  of  an  electric  current.  The  complete  apparatus 
is  called  a  motor  generator  when  both  parts  are  mounted  at  opposite 
ends  of  the  same  axle  and  revolve  as  one  solid  mass.  Such  an  apparatus 
(Fig.  105)  makes  it  practicable  to  convert  the  "direct"  500  volts  trolley- 
car  current  into  a  110  volts  current,  either  "direct"  or  alternating 


Fin.  105.       Rotary  transformer  or  motor  generator. 

for  electrotherapeutic  purposes.  It  requires  very  little  care,  and  is 
turned  on  and  off  as  readily  as  an  electric  light.  This  is  the  most 
practicable  type  of  apparatus  for  the  utilization  of  the  direct  current 
for  the  operation  of  the  type  of  .r-ray  apparatus  which,  like  Gaiffe's, 
employs  a  step-up  transformer. 

Polyphase  Currents  and  Polyphase  Dynamos  and  Motors. — 
Poll/phase  current^  in  their  practical  application  were  the  discovery 
of  Nikola  Tesla.  They  are  produced  by  a  dynamo,  usually  with  the 
Gramme  ring  type  of  armature',  by  making  the  connections  in  such  a 
manner  that  similar  alternating  currents  are  sent  out  through  two 
different  sets  of  conductors  at  different  periods  in  the  cycle  of  the 
dynamo.  The  diagrams  represent  the  production  and  characteristics 
of  a  diphase  current.  The  ring-wound  armature  is  supposed  to  be 
fixed  between  two  rotating  field  magnetic  poles  placed  at  the  sides, 
and  not  shown  in  the  diagram.  A  current  derived  from  the  armature 
at  a  and  l>  would  have  the  maximum  strength,  and  such  a  direction 
that  (i  would  be  the  positive  and  b  the  negative  pole.  Conductors 
leading  from  c  and  </.  the  parts  of  armature  at  this  time  in  a  direct  line 
with  two  field-magnets,  would  be  devoid  of  current.  As  the  field- 
magnets  rotate,  the  cin-rent  in  the  conductors  ti  and  b  becomes  less  and 


12S 


MEDICAL    KLKCTKICITY    AM)    RONTGEN    KAYS 


less,  and  that  in  r  and  <l  greater  and  greater,  until,  at  an  angle  of  45 
dr^nvs  measured  from  the  original  position,  the  currents  in  both  sets 
of  conductors  arc  equal  in  and  the  same  direction.  At  i)()  degrees  the 
current  in  c  and  <l  has  reached  its  maximum,  and  that  in  n  and  h  is  zero. 
At  13")  decrees  the  current  in  <i  and  h  has  changed  in  polarity  and  is 
as  strong  in  1  he  new  direction  as  that  in  r  and  d  is  in  the  original  direction. 
The  latter  is  diminishing,  the  former  increasing,  in  strength,  and  at 
ISO  degrees  the  current  in  n  and  h  has  reached  its  maximum,  with  h 
the  positive  and  n  the  negative  pole,  and  the  current  in  <•  and  d  has 


Fit:.    lO'i. — PolypluiM'  current-,  and  draminc'.-  riii<: 


become  zero.     The  remainder  of  the  cycle  brings  about  changes  which 
re-tore  the  original  condition  of  the  two  currents. 

Tr>'/>!'-  I'h'ist  Current-*. — As  far  as  concerns  the  two  wires  of  any 
particular  circuit  from  a  triple  phase  generator  they  transmit  simply  a 
regular  alternating  current,  usually  of  sixty  cycles.  And  it  is  only  when 
the  three  pairs  of  wires  lead  to  three  related  but  not  necessarily  contin- 
uous parts  of  th"  same  electrical  machinery  that  the  advantage  is  seen. 

Comp(iri*on  Between  Mechanical  Movement  find  Triple  Plntxe  Cur- 
rent.*,  -Figure  107  shows  three  engine  pistons  (P,  P1.  P-)  connected  by 
toggle  joints  with  three  different  parts  of  the  circumference  of  a  wheel 
which  they  are  to  rotate.  A  cycle  for  P-  would  carry  it  from  its  present 
position  at  the  forward  end  of  its  excursion  to  the  back  end  of  the 
cylinder  and  attain  to  the  forward  end.  All  three  pistons  go  through 
similar  cycles,  but  at  times  differing  from  each  other  by  ^'f.'(\  of  any  cycle; 
or  120'  as  a  rotation  of  the  wheel  takes  place  in  any  cycle.  P-  in 
the  diagram  is  obviously  at  a  place  where  it  cannot  apply  any  rotary 
force  to  the  wheel.  In  mechanical  parlance  P-  is  at  a  dead  center,  and 
if  it  were  the  only  piston  there  would  be  two  points  in  each  cycle  where 
no  rotary  power  would  be  applied  by  it.  A  single  piston  moving  back 
and  forth  would  !>-•  analogous  to  an  ordinary  alternating  current.  With 
three  pi-ton-  120J  apart,  as  in  the  diagram,  two  of  them  are  exerting 
rotary  power  even  when  one  is  at  a  dead  center,  and  there  is  never  a 
moment  \vh<-n  there  is  not  a  very  great  efficiency  in  the  application  of 
condition  is  analogous  to  the  mechanical  advantage  of 
i  a  s ;  • 

•>•    f  .*<   "/    'I  npli    l*h<i.*<   Current*  in  <tu  .r-llmi  (i<  nrrnlor.--- 
the  220  volts  direct   electric  light   current    to  actuate  a   motor- 
producing    triple    phase    current-.      The    different    circuits    to 


as   to  form   in    effect    a  (Irani    ring    with 
around    it.     About     IS    secondary    coils 
ten-ion  secondary  current   and  collecting 
lv   with   the   progress  of  the   triple   phase 


DYNAMIC    KLKCTKICITY 


120 


Triple  phase  current*  are  utilized  by  having  pairs  of  wires  carrying 
to  circuits  of  electric  lamps,  for  instance,  an  alternating  current  which 


Fig.   107. — Triple  phase  currents  illustrated  by  the  effect  of  three  pistons  upon  ;i 


rotating  wheel  to  which  they  are  connected   at  an  angle  of   120°.       At  every  instant   ai 


east  two  pistons  are  applying  motive  power 


may  be  derived •  from  coils  of  the  generator  in  several  different  ways. 
In  the  six-wire  system  the  two  leads  for  any  external  circuit  start  from 
the  two  ends  of  the  same  coil  of  the  generator.  Kach  of  the  three1  coils 


I- is:.  l()j>. — Triple  phase  current   curves.      There  is  alwavs  effective  current  in  at  least  tw<. 


supplies  an  external  circuit   independently.     This  method  is  not   com- 
monly employed. 

A  gamma  (/)  connection  with  a  common  return  wire  has  one  end 

9 


130 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


of  each  of  the  three  coils  connected  with  a  neutral  wire.  Each  external 
circuit  is  connected  with  this  neutral  wire  and  with  a  wire  going  to  the 
other  end  of  one  of  the  three  coils. 

The  star  or  gamma  (/M  connection  has  one  end  of  each  of  three  coils 
connected  at  a  neutral  point  X.     The  other  end  of  each  coil  has  a  line 


Fit:.  lO'.K — Triple  pha.-e  currents.     S^tar  or  Y  distribution  with  a  common  return  wire. 

LINE    A 


Fig-  110. — Triple  phase  currents.      Star  or  Y  distribution  without  a  return  wire. 

leading  from  it  through  a  separate  circuit   of  lamps,  for  example',  to  a 
common  neutral  point  Y.  from  which  no  re-turn  wire  is  requiivel. 

In  the  delta  connection  the-  coils  are  connected  in  such  a  way  as 
to  form  a  complete  circuit,  and  le-ad  wire's  start  from  three-  of  the-  junc- 

tions.     Any  two  of  these  lead 
if\     wires  may  supply  a  set  of  elec- 
p     trie    lamps   or  elertric  motors. 
<     It  looks  as  if  all  but  a  small 
\     amount   of    the1   current    gener- 
,     I     ate'd    would    pass    through   the 

\^ ^-^     circuit  formed  by  the1  coils  and 

Fin.  111.— Triple  plmse  currents.  Delta  very  little-  would  go  through 
rlistribution.  Kach  set  of  lumps  receives  power  the  thive  external  e'ircuits  with 

their  greal  resistance^  But  as 
a  matter  of  fact  this  is  a  ve-ry  effective-  way  of  applying  electric  power. 

If  the  current  instead  of  sixty  cycle's  a  seremd  had  about  a  elozen 
cycles  a  minute  we  should  be-  able  to  see  each  set  of  lamps  in  succession 
UTadually  liu'ht  up  and  then  gradually  go  out  entirely.  And  if  1  he-re 
were  meter,-  in  serie-  with  the  lamps  each  meter  in  sueression  would 
.-ho\\  a  gradual  increase  of  current  in  one  direction,  then  a  gradual  re- 
duction to  zero,  then  a  gradual  increase  in  t  he  either  direct  ion.  and  again 
a  gradual  ret  urn  to  zero. 

YY''///<  />hd.-i  currt-nlfi  form  the1  primary  current  in  the  author's 
generator  of  hi<ih  tension  direct  cm-rent  for  actuating  an  ./--ray  lube 
(p.  l_>s  . 

A  /ml  i//>//a.--i  /I I///H I/in  ma\'  be  absolutely  tVee  from  sparks,  and  may 
not  have  any  uninsulated  surface  anywhere1.  It  may  be  made  with- 
out commutator-  or  bru-lie,-.  The  field-magnets  may  be  powerful  per- 
manent magnet.-,  with  completely  insulated  short-circuited  windings, 


DYNAMIC    ELECTRICITY  131 

in  which  currents  of  the  proper  direction  are  induced  by  the  currents 
in  the  armature  coils.  The  ring  armature  is  stationary,  and  the  four 
or  more  conductors  leading  from  it  have  soldered  connections  with  its 
coils,  and  the  whole  may  he  insulated.  The  points  a  and  b  and  c  and  d 
are  stationary,  but  the  current  flow  in  consequence  of  the  rotation  of 
the  field-magnets  is  the  same  as  if  the  armature  was  revolving  and  the 
fields  stationary.  The4  same  absence1  of  movable  contacts  and  of  conse- 
quent sparking  is  found  when  the  polyphase  currents  are  utilized  for 
operating  a  motor  or  a  rotary  converter.  It  makes  electric  power  avail- 
able in  mines  and  factories,  where  the  slightest  spark  would  cause  a 
dangerous  explosion.  Polyphase  currents  are  directly  available  for 
the  operation  of  motors,  while  ordinary  alternating  currents  are  not. 
They  are  also  of  the  greatest  value  commercially  for  the  transmission  of 
power  in  the  form  of  electric  currents.  The  power  transmitted  is 
represented  by  the  number  of  watts  or  the  amperes  multiplied  by  the 
volts,  and  since  the  heating  effect  upon  the  wire  is  practically  dependent 
solely  upon  the  number  of  amperes,  the  amount  of  copper  required  is 
much  less  with  a  high  voltage  and  low  amperage  than  with  a  low  voltage 
and  great  amperage.  The  transmission  of  triphase  currents  at  6600 
volts  costs  less  than  1  per  cent,  as  much  for  copper  conductors  as  the 
transmission  of  the  same  amount  of  energy  over  the  same  distance  in 
the  form  of  a  oo()  volts  direct  current.  The  higher  voltage  is  conse- 
quentlv  employed  for  the  transmission  of  electric  power  for  long  dis- 
tance's, as  from  Niagara  Falls  to  neighboring  towns.  The  insulation 
must  be  very  complete,  first,  to  avoid  expensive  leakage  of  current 
under  this  high  pressure,  and,  second,  because  accidental  contact, 
direct  or  indirect,  with  a  current  of  this  character  could  hardly  fail  to 
be  fatal  to  animals  or  men.  Indeed,  even  in  the  power-house,  where 
this  current  is  converted  by  transformers  and  rotary  converters  into  the 
o'K)  volts  direct  current  supplied  to  the  trolley  line,  the  workmen  are 
liable  to  develop  obscure  nervous  disorders.  These  occur  without  any 
accidental  contact  with  the  conductors,  and  are  not  due  to  leakage 
of  current,  but  to  the  influence  of  expanding  and  contracting  lines  of 
force.  That  there  should  be  an  effect  upon  the  men  is  easily  understood 
when  we  consider  the  physical  and  physiologic  effects  produced  by 
proximity  to  an  Oudin  resonator  or  a  D'Arsonval  transformer  (both  of 
them  employed  therapeutically),  without  actual  contact  or  sparking. 
Accidental  contact  with  the  oo()  volts  direct  trolley  current  may  be 
fatal  to  men,  but  is  not  always  so.  It  usually  is  to  horses,  partly  on 
account  of  their  iron  shoes,  while  men  are  partially  insulated.  A  trolley 
wire  may  become  an  especial  source  of  danger  if  it  comes  in  contact 
with  a  wire  carrying  the  electric  arc-light  current. 

Polyphase  currents  are  useful  therapeutically  if  the  proper  voltage. 
amperage,  and  periodicitv  are  provided.  A  case  will  be  referred  to  in 
greater  detail  in  which  progressive1  muscular  atrophy  was  cured  by 
baths  through  which  triphase  currents  were  passed.  This  treatment 


sinusoidal  voltaic  current,  and  they  are  both  an  improvement  on  the 
direct  voltaic  current  interrupted  at  irregular  intervals  by  hand  for 
t  herapeut  ic  purposes. 

A  Rotary  Converter.  --This  has  been  alluded  to,  and  is  a  motor 
and  dynamo  combined.  It  is  used  for  the  conversion  of  cue  type  oi 
current  into  another,  and  may  be  constructed  to  yield  an  alternating 
or  a  direct  current,  or  a  polyphase  current,  and  of  any  ordinary  voltage. 


i;$2  MKDK'AL    KLECTRR'ITV    AND    RONTCKX    HAYS 

But  extremely  high  voltages  must  he  obtained  by  the  use  of  a  step-up 
transformer. 

A  small  apparatus  of  this  type  may  be  used  to  produce  the  sinusoidal 
voltaic  current,  and  indirectly  the  sinusoidal  faradic  currents,  which 
are  so  distinct  an  improvement  in  the  therapeutic  application  of  voltaic 
and  faradic  currents.  The  current  strength  and  direction  should  vary, 
as  represented  by  a  sine  curve  in  geometry.  In  other  words,  they 
should  produce  a  current  starting  at  zero  and  gradually  reaching  a 
maximum  in  one  direction,  diminishing  gradually  to  zero  and  then  in- 
crea>in«i-  gradually  in  the  other  direction,  and  then  gradually  diminish- 
ing to  zero,  as  in  the  apparatus  employed  by  the  author.  The  ap- 
paratus alluded  to  is  a  combination  of  a  variable  resistance  and  pole- 
clianger  actuated  by  an  electric  motor  (p.  4M'».  What  is  required  for 
some  pui-poses  is  a  current  varying  u'raduaily  from  maximum  to  mini- 
mum, and  then  with  a  reversed  polarity,  each  complete  cycle  taking  about 
two  seconds:  the  current  strength  or  amperage  to  be  regulated  by  a 
rheostat  in  circuit  with  the  patient. 

Power  of  Continuous  Current  Dynamos, — The  electromotive 
force  is  proportional  to  the  intensity  <jf  the  magnetic  field,  the  number 
of  turn-;  of  wire  moving  in  it,  and  the  speed  of  movement.  The  rise 
is  gradual  between  the  two  poles..  The  relation  between  the  electro- 
motive force,  the  current,  and  the  resistance  in  the  armature  in  a 
dynamo  obeys  Ohm's  law. 

Power  oif  Alternating  Current  Dynamos. — Here  the  relations  are 
somewhat  different,  it  being  found,  for  example,  that  doubling  the  speed 
does  not.  as  a  rule,  double  the  current,  although  it  does  double  the 
electromotive  force  and  will  send  the  original  current  through  twice 
as  much  external  resistance. 

Dynamos  designed  to  light  oOO  Hi-candle  power  lamps  have  arma- 
tures 10  inches  in  diameter,  and  make  about  7">0  revolutions  a  minute1; 
the  current  being  of  110  volts  and  '.•>}()  amperes.  About  70  per  cent, 
of  the  power  employed  to  run  the  machine  is  actually  utili/ed  in  the 
per  cent,  of  the  power  is  converted  into  elec- 

varii  His 


THE   INDUCTION    OF    DYNAMIC   ELECTRICITY  BY   ELECTRIC   CURRENTS 

There  are  two  principal  ways  in  which  a  cm-rent  of  electricity 
pas.-ing  through  a  coil  of  wire  will  produce  a  cm-rent  in  a  neighboring 
coil  of  wire.  In  the  first  place,  an  active  coil  or  one  through  which  a 
current  is  pa.-sm<£  may  be  moved  toward  and  awav  trom  the  other  coll. 
and  excite  currents  in  it  just  as  a  magnet  would.  The  same  effect  is 
produced  if  the  act  \\  e  coil  is  st  at  lonarv  and  the  other  moves.  In  either 
case  the  lines  of  force  about  the  active  coil  are  analogous  to  those  about 
a  magnet,  and  the  currents  produced  in  the  other  coil  are  due  to  the 
t  urn-  in  the  other  coil  cut  t  ing  t  h  rough  1  hese  lines  ot  torce  in  consequence 
of  the  motion  of  one  or  other  coil.  This  method  of  action  is  tullv 
ill  list  rated  in  t  he  dynamos  which  have  been  described,  and  in  which  the 
armatures  and  field-magnets  consist  ot  coils  oi  wire  which  are  no  less 
important  than  their  iron  and  steel  core.-. 

The  other  principal  method  is  by  induction,  by  which  variable 
•  -  -  in  one  stationary  coil  excite  currents  m  another  stationary 
coil. 

Induced  Currents.      It   has  alreadv  been  stated  that   a  continuous 


DYNAMIC    ELECTRICITY  133 

current  passing  through  one  wire  does  not  produce  a  current  in  a 
neighboring  wire  if  the  wires  are  both  motionless.  But  it  is  a  very 
different  matter  when  the  current  starts  or  stops  or  varies  in  strengt.li 
or  direction.  Kvery  such  change  in  the  active  wire  results  in  a  tem- 
porary current  in  the  other  wire.  The  simplest  case,  and  one  which 
shows  the  principle  upon  which  the  entire  system  of  induced  currents 
is  founded,  is  that  of  two  straight  parallel  wires  near  each  other  in  the 
air.  When  a  current  of  electricity  is  turned  on  or  begins  to  flow  through 
the  first  wire,  a  momenta]'}"  current  flows  through  the  second  wire  and 
in  the  opposite  direction.  While  the  current  is  flowing  uniformly  in 
the  first  wire,  no  current  flows  through  the  second  Avire.  When  the 
current  is  turned  off  in  the  first  wire,  a  momentary  current  is  produced 
in  the  second  wire,  and  this  is  in  the  same  direction  as  the  current  which 
has  just  ceased  to  flow  through  the  first  wire.  Changes  in  the  strength 
of  the  current  in  the  first  wire  produce  similar  effects;  an  increase  in 
current  induces  a  current  in  the  opposite  direction  in  the  second  wire, 
while  a  reduction  in  current  strength  in  the  first  wire  induces  a  current 
in  the  same  direction  in  the  second  wire. 

An  example  of  the  practical  application  of  the  induction  of  currents 
in  parallel  straight  wires  is  seen  in  the  process  of  telegraphing  from  a 
moving  railway  train.  In  this  case  the  series  of  dots  and  dashes  in  the 
Morse  alphabet  are  transmitted  as  a  series  of  interrupted  currents 
passing  through  a  wire  fixed  along  the  top  of  the  car.  Along  the  railway 
is  a  wire  running  parallel  with  the  one  on  the  car,  and  as  near  as  prac- 
ticable to  it.  The  currents  of  electricity  in  the  wire  on  the  car  induce 
currents  in  the  stationary  wire  which  actuate  telegraphic  instruments 
at  any  reasonable  distance  along  the  line.  This  is  due  to  simple  induc- 
tion, and  is  not  the  same  as  what  has  become  known  as  uirelexs  tclcg- 
r(tph;/.  and  which  will  be  alluded  to  again  in  another  part  of  this  book. 

Induced  currents  are  due  to  the  expanding  and  contracting  lines  of 
force  about  a  wire  through  which  a  current  of  electricity  passes.  The 
inducing  force  is  the  same  as  in  the  case  of  induction  of  an  electric 
current  by  the  motion  of  a  magnet;  and  in  this  case  the  relation  between 
the  inducing  and  the  induced  currents  may  be  very  simply  expressed 
as  already  mentioned. 

The  following  are  the.  /cnr*  of  induced  current*: 

1.  At   the  instant   when  the  primary  current  begins  to  flow  or  to 
increase   its  intensity,  an   induced  current,  inverse  and  momentary,  is 
developed  in  the  secondary  coil  or  circuit. 

2.  The  primary  current  approaching  the  conductor  gives  rise  to  an 
induced  current  in  the  secondary  coil,  inverse  and  momentary. 

.'•>.  At  the  moment  this  current  ceases,  or  when  its  intensity  dimin- 
ishes, or  when  the  primary  coil  recedes,  an  induced  current  begins  in 
the  secondary  coil  or  circuit,  direct  and  momentary. 

The  Induction  Coil. --This  is  in  practical  use  for  a  hundred  different 
torms  dt  elect  rot  herapeut  ic  apparatus,  as  well  as  for  commercial  pur- 
poses. It  consists  of  a  primary  coil,  a  secondary  coil,  an  interrupter, 
and  sometimes  a  condenser.  It  is  supplied  with  an  electric  current  by 
a  voltaic  battery,  a  storage  battery,  or  a  dynamo  circuit,  like  the 
electric-light  system.  It  yields  a  succession  of  induced  currents  which 
are  usually  ot  very  different  potential  from  the  primary  current,  beinir 
oi  much  higher  voltage  for  most  therapeutic  purposes.  And  these 
induced  currents  are  of  an  alternating  character. 


134  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

The  Primary  Coil. — The  coil  of  wire  through  which  the  current 
supplied  by  the  buttery  or  dynamo  passes  is  called  the  primary  coil, 
and  the  current  through  it  is  called  the  prunarij  current.  The  primary 
coil  usually  consists  of  a  small  number  of  turns  of  rather  coarse  copper 
wire,  which  is  insulated  by  a  wrapping  of  cotton,  and  which  is  wound 
in  a  single  or  a  few  complete  layers  covering  the  outside  of  the  bundle 
of  iron  wires  which  form  the  core  of  the  primary  coil.  The  two  ends 
of  this  coil  are  indirectly  connected  with  the  battery  or  dvnamo.  "NY hen 
the  electricity  is  turned  on,  the  primary  current  is  said  to  be  made; 
and  when  the  electricity  is  turned  off,  the  primary  current  is  said  to  be 
broken.  It  will  be  seen  later  that  the  currents  induced  in  the  secondary 
coil  occur  in  consequence  of  the  making  and  breaking  of  the  primary 
current,  and  that  they  are  called,  for  convenience,  the  make  and  break 
current*.  The  break  current  is  the  more  powerful,  and  for  x-ray  work 
is  the  only  current  desired. 

Two  circumstances  in  regard  to  the  primary  current  may  interfere 
with  the  most  effective  production  of  the  break  current.  They  arc  both 
produced  by  self -induction  in  the  primary  coil.  This  acts  especially 
to  induct^  a  break  current  in  the  primary,  which  forms  a  sort  of  con- 
tinuation of  the  primary  current,  and  is  in  the  same  direction:  and 
then  again  this  induced  break  current  in  the  primary  is  of  higher  voltage 
than  the  primary  current,  and  causes  an  electric  arc  at  the  interrupter 
where  the  current  is  broken.  Both  of  these  circumstances  interfere 
with  a  sudden  and  complete  breaking  of  the  primary  current,  and 
must  be  overcome  or  regulated  in  order  to  secure  the  best  results. 

Self-induction  in  the  primary  coil  is  illustrated  very  well  by  the 
simple  coils,  without  any  secondary  coil,  which  are  used  to  light  the 
gas  in  theaters  and  other  places  where  it  is  inconvenient  to  apply 
a  match  to  every  gas-jet.  If  the  current  from  a  dry-cell  battery  be 
passed  through  a  simple  coil  of  wire  and  then  be  quickly  cut  off  or 
bn>ken.  a  current  is  generated  by  self-induction  which  has  such  high 
voltage  that  it  will  leap  across  the  spark-gaps  at  all  the  different  burners 
and  ignite  the  gas.  The  original  current  from  one.  two,  or  three  cells 
of  a  drv  battery,  if  passed  through  a  short  straight  wire,  will  produce  a 
liny,  almost  invisible,  spark  across  a  very  small  fraction  of  an  inch  at 
the  switch  as  the  contact  is  broken.  But  if  the  wire  be  a  long  one  and 


the  switch  when  the  current  is  broken  may  be  even  a  third  of 
>ng.  A  self-induction  coil  may  be  used  for  tin1  same  purposes 
coil,  exciting  muscular  cont  ract  ion  and  the  ot  her  physiologic 
it  w<  >u Id  not  be  so  good  or  so  convenient  as  an  induct  ion  coil 
with  both  primary  and  secondary  windings.  The  presence  of  an  iron 
add.-  very  much,  indeed,  to  the  strength  of  the  secondary  current, 
it  has  long  been  considered  a  necessary  part  of  an  induction  coil. 
is  not  the  case,  however,  and  recent  observations  bv  Lewis  Jones 
show  that  equally  beneficial  results  with  less  discomfort  to  the  patient 
are  obtained  from  a  faradic  coil  without  an  iron  core. 

If  the  self-induction  from  a  .-mall  coil  and  a  couple  of  dry-cells 
produces  .-park  enough  to  light  a  great  number  of  gas-jet-,  it  is  easy  to 
understand  that  the  self-induction  in  a  large  primary  coil  like  that  of 
an  ./'-ray  machine,  actuated  by  the  currei 
(•ells  or  a  large  -torat^e  batterv  or  a  dvnar 


DYNAMIC    ELECTRICITY  1.5.) 

to  produce  an  electric  arc  between  the  contacts.  Arcing  at  the  switch 
must  be  prevented  because  the  intense  heat  will  injure  the  switch  and 
mav  set  fire  to  neighboring  objects.  \Yith  the  heavy  currents  employed 
for  x-ray  work  the  current  should  never  be  turned  on  and  off  by  the 
ordinary  key  switch  of  the  electric-light  socket.  If  such  a  socket 
is  used,  there  should  be  an  open  knife-switch  near  the  coil,  and  this  should 
always  be  turned  off  before  the  connection  is  either  made  or  broken  at 
the  lamp  socket.  There  is  thus  no  current  passing  when  the  lamp 
socket  key  is  turned  on  or  off,  and  consequently  no  arcing  there.  It  is 
better  still  to  have  the  feed  wires  pass  directly  to  the  knife  switches 
without  the  intervention  of  a  key  socket.  Even  at  the  knife-switch 
precaution  should  be  taken  against  the  formation  of  an  arc.  This 
will  not  occur  if  the  switch  is  opened  very  quickly,  and  special  switches 
(Fig.  112)  are  made  to  accomplish  this.  They  arc  closed  just  like  an 


ampere:- 


ordinary  knife-switch,  but  the  portion  of  the  blade  which  engages 
between  the1  two  springs  with  which  it  makes  a  contact  is  hinged,  so 
that  it  remains  held  in  position  by  friction  as  the  switch  is  opened  until 
the  strain  on  a  spring  between  the  rest  of  the  blade  and  the  hinged 
portion  becomes  great  enough  suddenly  to  draw  the  latter  out  from 
between  the  two  clutches.  An  instantaneous  break  like  this  is  not 
liable  to  produce  an  arc.  Xo  special  arrangement  for  making  a  quick 
contact  is  necessary.  1'ntil  the  contact  is  made  we  have  only  the  110 
volts  potential  to  deal  with,  and  this  will  not  leap  across  any  appreciable 
•^pace,  perhaps  only  y,',,-,  inch,  as  one  metallic  connection  is  brought 
toward  the  other.  There  is  no  current  flowing  through  the  primary 
coil,  and  so  no  self-induction  is  operative*  until  after  the  contact  has 
been  made.  The  make  spark  at  the  switch  which  turns  on  the  primary 
current  requires,  therefore,  no  consideration  except  for  the  fact  that  it 
will  ignite  inflammable  explosive  gases  if  they  are  present.  The 


13(5  MEDICAL    ELECTRICITY    AND    RONTGEX    RAYS 

break  spark  at  the  primary  switch  is  due  to  the  self-induction  in  the 
primary  coil,  and  when  the  1  10  volts  current  is  used  to  excite  an  x-ray 
coil,  this  spark  is  a  powerful  one.  It  is  of  importance  because  of  the 
tendency  to  produce  an  arc  between  the  terminals,  and  this  corrodes 
the  two  metal  surfaces  and  makes  it  difficult  to  press  the  knife  of  the 
switch  into  the  slot  between  the  two  springs  where  the  contact  is 
made.  It  also  produces  danger  of  fire,  and  the  switch  should  always 
be  mounted  on  a  slate  or  marble  base,  and  care  should  be  taken  to  keep 
inflammable  substances  out  of  reach.  There  is  the  possibility  of  an  arc 
forming  across  the  whole  space  when  the  switch  is  turned  off  and  the 
current  continuing  to  flow  across  the  space  as  an  electric  arc.  This 
would  most  effectually  ruin  the  switch  by  fusing  the  metallic  terminals. 
To  obviate  this  possibility  the  terminals  should  be  placed  so  far  apart 
that  it  will  be  impossible  to  strike  an  arc  between  them. 

A  l;tii/(-»irilclt  intended  to  turn  off  and  on  a  primary  current  of  110 
volts  and  up  to  3o  amperes  should  not  have  a  space  of  less  than  1|  inches 
between  any  of  its  stationary  metallic  terminals.  In  practice  it  is  not 
usually  necessary  to  have  a  quick  break  attachment,  but  it  is  necessary 
to  have  a  knife-switch  instead  of  the  ordinary  key,  such  as  is  used  to 
turn  an  incandescent  lam])  on  and  off,  and  care  should  be  taken  to  open 
the  switch  quickly  every  time  that  the  current  is  turned  off.  In  the 
case  of  a  portable  outfit  carried  to  a  patient's  home  and  connected  with 
an  electric-light  socket,  an  ordinary  key  receptacle,  there  should  be  a 
knife-switch  on  the  x-ray  apparatus,  and  this  should  be  open  while  the 
attachment  is  made  at  the  electric-light  socket.  The  x-ray  apparatus 
should  not  be  in  con  dit  ion  to  operate  while  the  connection  is  being  made  or 
broken  at  the  elec t  ric-light  socket.  No  current  should  be  flowing  when  the 
electric-light  key  is  turned  off,  and  care  should  betaken  to  see  that  the 
knife-switch  on  the  x-ray  apparatus  is  turned  off  before  the  electric- 
light  key  is  turned  either  on  or  off.  When  this  is  done,  it  will  be  found 
that  the  heavy  current  will  be  carried  all  right  by  a  lamp  receptacle  in 
which  the  contacts  are  good,  while  it  would  very  probably  burn  out  the 
contacts  to  turn  a  heavy  current  on  or  off  at  this  point.  Properly  used, 
the  lam])  socket  simply  brings  the  supply  of  electricity  to  the  knife- 
switch  of  the  x-ray  coil,  and  it  is  imperative  that  the  latter  should  be  the 
place  where  the  current  to  the  x-ray  coil  is  turned  on  or  off. 

The  same  self-iiu  luct  ion  in  the  primary  produces  the  little  spark 
which  is  always  seen  between  the  contacts  where  the  primary  current 
of  a  laradic  battery  is  made  and  broken.  The  spark  makes  it  desirable 
to  have  the  contact  s  made  of  platinum  or  some  ot  her  met  al  which  is  not 
easily  corroded.  P>ut  with  the  weak  currents  employed  for  this  purpose, 
sometime-  supplied  by  a  single  drv-cell.  no  special  precautions  need  be 
taken  except  to  keep  inflammable  gases  awav  from  it. 

The  1  Id  volts  direct  current,  if  not  interrupted,  could  be  drawn  out 
into  an  arc  several  inches  long  if  a  current  of  a  good  many  amperes  had 
been  flowintr.  and  it'  the  contacts  were  separated  slowly.  The  current  is 
practicallv  completely  broken  bv  the  \Yehnelt  interrupter,  however, 
and  no  .-park  or  arc  can  last  more  than  an  exceedingly  small  part  of  a 
second  as  the  .-witch  i-  opened.  A  break  in  the  circuit  occurs  at  the 
platinum  point  immersed  in  the  liquid,  and  when  a  good  contact  is 
reestablished  at  that  point,  the  metallic  contact  at  the  switch  has  been 
completely  broken.  Kven  though  there  mav  be  a  break  spark  at  the 
switch  from  -elf-induction  in  the  primary,  the  .-park  is  of  only  momen- 
tary duration  when  the  Wehnelt  or  other  good  interrupter  is  used. 


DYNAMIC    ELECTRICITY  137 

With  ordinary  care  about  making  a  quick  bmik  one  may  use  an  ordinary 
knife-switch  for  interrupted  currents  as  strong  as  25  amperes,  with  no 
other  inconvenience  than  the  occasional  necessity  for  filing  the  contacts 
smooth  where  they  have  been  fused. 

This  does  not  at  all  mean,  however,  that  it  is  safe  to  turn  a  current 
of  this  strength  on  and  off  by  means  of  an  ordinary  electric-light  key. 
The  electric-light  socket  may  cany  quite  a  heavy  current  if  there  is  a 
knife-switch  at  the  coil  which  is  turned  off  both  when  the  electric-light 
key  is  turned  on  and  when  it  is  turned  off.  In  this  way  the  electric- 
light  key  connects  or  disconnects  the  knife-switch  with  the  source  of 
supply,  but  does  not  itself  turn  the  current  on  or  off. 

Recurring  to  the  subject  of  self-induction  in  the  primary  of  an  rr-ray 
coil,  it  must  be  seriously  considered  in  the  construction  of  any  type 
of  interrupter  for  making  and  breaking  the  primary  current  hundreds 
or  thousands  of  times  a  minute.  With  a  current  strong  enough  to  do 
the  best  x-ray  work,  it  is  difficult  to  do  this  by  any  apparatus  which 
makes  and  breaks  the  contact  in  the  open  air,  although  there  arc 
interrupters  of  this  type  which  work  well  with  moderate  currents.  With 
the  most  powerful  currents,  no  open-air  interrupter  will  accomplish 
the  result:  there  will  be  arcing,  and  the  current  flow  will  not  be  inter- 
rupted. Generally  speaking,  the  self-induction  spark  makes  it  necessary 
to  use  either  a  mechanic  interrupter  in  which  the  metallic  contact  is 
made  and  broken  beneath  the  surface  of  some  liquid  or  gas  which  sup- 
presses the  arc,  or  a  liquid  interrupter  of  the  Wehnelt  or  of  the  Cald- 
well-Simon  type,  in  which  the  two  metal  terminals  arc  always  wide 
apart,  and  the  interruptions  are  due  to  an  effect  of  the  current  itself 
in  flowing  through  the  liquid. 

The  self-induction  in  the  primary  of  an  .r-ray  coil  makes  it  act  like 
a  choke  coil.  With  the  same  conditions  in  every  respect,  except  that 
in  one  case  there  is  great  and  in  the  other  little  self-induction,  the 
current  strength  which  will  pass  through  the  primary  coil  is  markedly 
greater  when  there  is  little  self-induction. 

A  Choke  Coil. — If  a  coil  of  wire  forms  part  of  an  electric  circuit 
through  which  an  alternating  or  an  interrupted  current  passes,  the 
self-induction  in  the  coil  may  be  so  adjusted  as  to  impede  the  flow  of 
the  current  to  almost  any  desired  extent.  A  coil  made  for  this  purpose 
is  called  a  choke  coil.  The  impedence  which  it  offers  is  not  analogous 
to  friction,  as  is  the  impedence  offered  by  a  thin  straight  wire  to  the 
passage  of  a  continuous  current.  In  the  case  of  ordinary  resistance  the 
reduction  in  current  strength  is  accompanied  by  the  heating  of  the 
conductor  and  to  that  extent  there  may  be  a  loss  or  waste  of  power  by 
the  conversion  of  electrical  energy  into  heat.  A  choke  coil,  on  the 
contrary,  will  reduce  the  amount  of  current  flow  by  an  inductive1  action 
without  proportionate  heating.  If  ordinary  electric  resistance  is 
likened  to  friction,  then  the  impedence  offered  by  a  choke  coil  may  be 
likened  to  that  of  an  opposing  force  exerting  traction  in  a  direction 
opposed  to  the  force  by  which  a  body  is  being  moved.  Where  it  is 
applicable,  self-inductance  is  preferable  to  resistance  as  a  means  of 
reducing  or  regulating  current  strength.  It  obviates  the  danger  of 
fire  and  the  wear  and  tear  on  a  resistance  coil  from  the  heating  effect 
of  the  current,  and  is  much  more  economic  of  electric  cnergv.  Self- 
inductance  so  arranged  as  to  produce  a  choke  coil  means  that  in  regard 
to  any  individual  turn  when  the  current  is  made  it  induces  in  all  the 
neighboring  turns  a  current  in  the  opposite  direction,  and  that  the  mutual 


188  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS, 

relation  between  the  original  potential,  which  tends  to  send  a  current: 

through  all  the  turns  of  the  coil,  and  the  counter  electromotive  force 
developed  by  inductance  in  the  turns  of  the  coil  is  such  as  to  reduce  the 
strength  of  the  primary  current  to  a  certain  definite  extent.  Impedence 
by  self-inductance  produces  a  tendency  to  side  flashing.  Take  the  case 
of  a  choke  coil  ami  a  1 10  volts  interrupted  direct  current,  the  coil  being 
so  wound  that  a  current  of  only  11  amperes  will  flow  through  it.  Then 
the  two  wires  leading  to  the  coil  must  be  kept  wide  apart,  because  there 
will  be  a  tendency  for  an  induction  spark  to  flash  across  between  them. 
Xo  such  tendency  would  be  noted  in  the  case  of  a  1  10  volts  interrupted 
direct  current  regulated  to  a  current  strength  of  1 1  amperes  by  an 
ordinary  resistance.  In  fact,  in  the  latter  case  a  much  shorter  spark 
will  pass  between  the  two  wires  leading  to  the  resistance  than  would 
pass  between  two  loose  ends  of  wire,  forming  the  terminals  of  the  110 
volts  circuit. 

A  choke  coil  is  available  instead  of  a  rheostat,  or  resistance,  for 
regulating  the  strength  of  current  for  an  .r-ray  coil.  and.  in  fact,  the 
primary  coil  of  an  .r-ray  outfit  itself  very  often  performs  the  function. 
In  the  author's  12-inch  .r-ray  coil  the  self-induction  in  the  primary  coil 
when  the  current  (110  volts  direct  incandescent  light  current  modified 
by  a  Wehnelt  interrupter)  has  to  pass  through  the  two  layers  which 
form  the  whole  length  of  the  primary  wire,  is  much  greater  than  when 
the  connections  are  made  in  such  a  way  that  the  primary  current  passes 
through  only  one  layer  of  the  coil.  There  is  quite  a  difference  in  the 
current  strength  which  will  be  transmitted  in  the  two  cases  with  the 
rheostat  turned  to  no  resistance  and  only  the  flat  end  of  the  platinum 
rod  exposed  to  contact  with  the  electrolyte  in  the  Wehnclt  interrupter 
and  with  an  .r-ray  tube  of  the  same  degree  of  vacuum  in  the  secondary 
circuit.  "With  great  self-induction  the  primary  current  will  be  only 
4  amperes,  while  the  moment  the  connection  is  changed  to  a  small 
amount  of  self-induction  the  current  increases  to  .V,  amperes.  The 
increase  in  current  is  not  due  to  the  lessened  ohmic  resistance  from 
pa»age  through  a  shorter  length  of  wire,  for  there  is  only  about  one 
ohm's  resistance  in  the  whole  primary  coil,  and  this  forms  an  insig- 
nificant fraction  of  the  total  resistance  in  the  primary  circuit.  The 
difference  in  current  strength  is  due  almost  entirely  to  the  difference  in 
the  amount  of  self-induction.  \Yhen  the  interrupter  is  arranged  to  per- 
mit a  much  heavier  current,  the  difference  in  self-induction  is  still  more 
evident,  and  with  the  largest  self-induction  the  primary  coil  acts  really 
as  a  choke  coil,  and  no  matter  how  much  of  the  platinum  point  may  be 
exposed,  not  more  than  10  or  12  amperes  of  current  will  pass  through 
the  primary  coil.  But  with  a  small  amount  of  self-induction  a  current  of 
1 .")  or  20  or  even  2">  amperes  may  be  made  to  pass.  The  aut  hor's  S-inch 
.c-ray  coil  has  a  primary  in  which  three  different  lengths  of  wire  or num- 
may  be  used,  and  the  variable  self-induction  obtained  in 
iffers  a  valuable  means  of  regulating  the  strength  of  the 
'rent.  In  tact,  with  this  apparatus,  which  is  a  portable  one. 
of  amperemeter  is  required.  The  different  lengths  of  the 
iint  exposed  to  contact  with  the  liquid  electrolyte,  in  the 
errupter.  and  the  different  amounts  of  self-induction  in  the 
dinu'.  regulate  the  110  volt-  direct  or  alternating  current  to 
-t  rengt  h.  Of  collide,  it  was  de-irable  in  t  he  beginning  to  have 
an  amperemeter  in  t  he  circuit  to  mea-ure  t  he  current  st  rengl  h  wit  h  all  the 
various  combination-,  and  a  table  \va>  made  out  >ho\ving  the  results. 


DYNAMIC    ELECTRICITY  139 

A  separate  choke  coil  may  be  used  to  regulate  the  strength  of  current 
supplied  to  an  .r-ray  apparatus  by  introducing  any  desired  impedence 
to  the  passage  of  the  current.  It  is  especially  useful  with  the  alter- 
nating electric-light  current.  And  when  it  is  separate,  it  effects  a 
regulation  of  the  current  strength  without  producing  variations  in  the 
inductive  relations  between  the  primary  and  the  secondary  coils.  A 
separate  choke  coil  may  be  used  to  regulate  the  current  strength  and 
take  the  place  of  a  rheostat.  When  different  layers  of  the  primary 
coil,  however,  are  used  for  a  choke  effect,  we  have,  besides  that  effect, 
a  change  in  the  amount  of  induction  in  the  secondary  coil,  due  to  the 
passage  of  the  primary  current  through  a  greater  or  less  number  of  turns 
of  wire.  The  voltage  of  the  secondary  current  depends  more  than 
anything  else  upon  the  ratio  between  the  number  of  turns  in  the  second- 
ary coil  and  the  number  in  the  primary  coil.  And  if  the  latter  number 
is  increased,  the  voltage  of  the  secondary  current  will  usually  be  dimin- 
ished, and  its  volume  or  amperage  will  usually  be  increased. 

In  connection  with  the  subject  of  self-induction,  it  must  be  borne 
in  mind  that  two  currents  of  electricity  do  not  flow  through  the  same 
wire  at  the  same  time,  either  in  the  same  or  in  opposite  directions. 
Under  any  circumstances  a  current  of  electricity  takes  place  in  conse- 
quence of  a  difference  of  potential  at  the  two  ends  of  the  wire,  and. 
other  things  being  equal,  the  current  strength  is  determined  by  the 
difference  in  potential.  The  difference  in  potential  is  produced  by  the 
application  of  power  derived  from  chemic  action  in  the  case  of  a  voltaic 
battery  or  of  a  storage-cell,  or  from  electric  or  magnetic  induction  and 
mechanic  motion  in  the  case  of  induction  coils  and  dynamos.  The 
difference  in  potential  or  voltage  is  an  index  of  the  strength  of  the 
electromotive  force.  In  the  case  of  a  simple  wire  connecting  the  two 
poles  of  a  voltaic  battery  in  operation  the  electromotive  force  is  a 
simple  force  exerted  in  only  one  direction  and  a  current  of  corresponding 
strength  will  flow  through  the  wire.  But  now  if  another  voltaic  batten- 
is  connected  in  series  with  the  first  battery  and  the  same  simple  wire,  we 
shall  have  its  electromotive  force1  also  operative.  If  the  two  are  exerted 
in  the  same  direction,  their  effects  will  be  added  and  the  current  strength 
will  be  determined  by  the  sum  of  the  voltage  of  the  two  batteries.  If. 
on  the  other  hand,  the  two  batteries  are  so  connected  that  they  would 
tend  individually  to  send  a  current  through  the  conducting  wire  in 
opposite  directions,  then  the  resultant  current  will  flow  through  the 
wire  in  the  direction  controlled  bv  the  battery  having  the  greater 
electromotive  force,  and  the  current  strength  will  correspond  to  t he- 
difference'  between  the  two  opposing  electromotive  forces  or  voltages. 
The  potentiometer  for  measuring  the  electromotive  force  of  a  voltaic 
cell  or  battery  employs  this  principle. 

Self-induction  may  cause  a  counterelectromotive  force  tending  to 
produce  currents  simultaneously  with  the  initial  currents,  and  opposed  to 
them.  An  illust  ration  of  this  condit  ion  may  be  found  in  the  case  of  a  force- 
pump,  like  a  fire-engine,  sending  water  through  a  hose-pipe  and  actuated 
by  a  constant  steam  pressure.  When  the  nozzle  is  at  the  same  level  as 
the  pump,  the  rate  of  flow  will  be  regulated  by  the  resistance  due  to 
friction,  and  this  will  depend  upon  the  caliber  and  length  of  the  hose- 
pipe. But  if  the  hose-pipe  is  carried  up  to  the  second  or  third  ston 
of  a  house,  a  counterpressure  is  produced  by  the  force  of  gravity,  and 
the  rate  of  flow  will  correspond  to  the  difference  between  the  pressure 
exerted  bv  the  steam  and  that  exerted  bv  gravitv.  The  frictiona! 


140  MKDK  AL    ELECTRICITY    AND    ROXTGEN    RAYS 

resistance  in  this  illustration  is  analogous  to  ohmic  resistance,  or  the 
electric  resistance  which  can  he  measured  in  ohms  and  which  depends 
upon  the  electric  conductivity  of  the  wire  and  its  length  and  thickness. 
The  counterpressure  due  to  the  force  of  gravity  is  analogous  to  the 
rounterelectroinotive  force  developed  by  self-induction. 

Self-induction  may  be  used  to  render  an  intermittent  current 
practically  continuous.  The  break  current  or  the  electromotive  force 
induced  when  the  initial  current  ceases  to  flow  is  a  powerful  one.  and 
is  in  the  same  direction  as  the  initial  current,  and  may  bridge  over 
the  period  between  one  pulsation  of  the  initial  current  and  the  next. 
In  such  a  case  the  make  current  or  the  electromotive  force  induced 
when  the  initial  current  again  begins  to  flow  is  in  the  opposite  direction. 
and  reduces  the  flow  of  the  initial  current  to  some  extent.  The  current 
How  may.  therefore,  be  practically  continuous  and  of  uniform  strength. 
Such  self-induction  coils  are  in  use  in  connection  with  a  mercury  arc 
rectifier  as  part  of  the  apparatus  employed  for  converting  an  alternating 
current  into  a  direct  current,  suitable  for  charging  storage-batteries. 

Self-induction  Dependent  upon  the  Nature  of  the  Initial  Cur- 
rent. —  There  is  practically  no  self-induction  produced  by  the  passage 
of  a  continuous  current  through  a  straight  wire.  But  when  the  current 
is  one  of  an  alternating  character,  especially  if  of  very  high  tension,  the 
self-induction,  even  in  a  short  straight  wire,  becomes  so  great  as  to 
offer  an  impedence  as  great  as  that  of  an  air-space  of  one  or  more 
inches.  Under  most  conditions,  if  the  two  terminals  of  a  source  of  elec- 
tromotive force  are  connected  with  the  ends  of  a  short  heavy  copper 
wire,  every  bit  of  the  current  will  pass  through  the  wire,  and  even  if 
its  ends  are  bent  around  so  as  to  be  within  an  exceedingly  small  distance 
of  each  other,  no  spark  will  cross  that  space.  But  with  the  modern 
high-frequency  current  apparatus  for  therapeutic  use  the  self-induction 
developed  in  the  wire  offers  so  great  an  impedence  that  the  current  will 
flash  across  a  space  sometimes  as  great  as  4  inches,  instead  of  passing 
through  a  foot  or  two  of  a  heavy  copper  wire.  This  is  in  spite  of  the 
fact  that  the  ohmic  resistance  of  the  copper  wire  may  be  so  slight  that 
it  would  tranmit  a  thousand  times  that  amount  of  power  in  the  form  of 
a  continuous  current  of  either  high  or  low  voltage. 

The  amount  of  reactance  or  counterelectromotive  force  due  to  self- 
induction  is  usuallv  diminished  by  adding  to  the  capacity  of  the  circuit 
or  bv  the  use  of  a  condenser,  and  this  is  one  reason  for  the  necessity  of 
a  condenser  in  the  Huhmkorff  coil. 

The  tot;d  impedence  in  a  circuit  is  usually  made  up  of  the  ohmic 
resistance  and  the  reactance  or  self-induction,  and  usually  the  square 


resistance  and  the  reactance.  Thus,  if  the  ohmic  resistance  is  '.]  ohms 
and  the  reactance  \  ohm.-,  and  the  current  an  alternating  one  ot 
.")(  I  cvcles  a  second,  and  the  voltage  1  20.  the  total  impedence  would  be 
.")  ohm-  '_'">.  the  -i|i  ia  re  of  .">  !)  •  Hi,  the  sum  ot  the  squares  ot  '.]  and  4  ). 
'J  he  reactance  would  be  increased  bv  the  presence  ot  a  sot  t  -iron  core. 

Kven  the  two  supply  wires  have  an  inductive  effect  upon  each  other 
which  ha-  to  l.c  taken  into  account  m  electric  lighting  and  power 
systems.  A-  an  example,  an  alternating  current  passing  through  two 
wire-  ot  %J~»0.()U(i  circular  mils,  and  1  inches  apart  to  a  ">0  horse-power 
t  away,  suffers  a  loss  of  (>..">  per  cent,  from  inductive  re- 


DYNAMIC    ELECTRICITY  141 

The  unit  of  inductance  is  the  henry,  and  equals  the  inductance  of  a 
circuit  when  the  electromotive  force  induced  in  it  equals  1  volt,  when 
the  exciting  current  varies  at  the  rate  of  1  ampere  a  second.  And 
if  a  counterelectromotive  force  of  1  volt  is  set  up  in  a  circuit  when  the 
current  is  increased  at  the  rate  of  1  ampere  per  second,  then  the  self- 
induction  of  the  circuit  is  equal  to  1  henry. 

The  henry  is  the  unit  of  induction  in  all  eases,  not  merely  in  that  of 
self-induction. 

The  construction  of  coils  to  have  a  certain  self-induction  is  largely 
experimental,  and  the  details  are  different  with  each  different  com- 
bination of  current  and  apparatus.  The  primary  windings  which 
produce  the  most  desirable1  amounts  of  self-induction  in  .r-ray  coils 
are  described  with  practical  details  in  the  chapter  on  .r-ray  coils. 

The  Oudin  resonator  furnishes  a  most  striking  example  of  self- 
induction.  An  alternating  current  of  very  high  tension  and  high- 
frequency  supplied  by  an  induction  coil  and  two  Leyden  jars  passes 
through  one  or  two  or  three  or  more  turns  of  wires  and  beyond  one  of 
the1  terminals  the1  wire1  is  continued  in  an  ascending  spiral  for  twenty  or 
thirty  turns.  The  bare  binding  posts  by  which  the  wire  from  the 
Leyden  jars  are1  connected  with  the  wire1  of  the  Oudin  resonator  may  be 
touched  by  the  finger  without  receiving  a  disagreeable  spark.  But  the 
effect  is  multiplied  by  each  turn  of  wire1,  and  at  the  free  end  of  the' 
resonator  the  wire  gives  off  an  electric  effluve  or  visible  brush  discharge. 
3  or  4  inches  long,  and  if  the  finger  is  brought  within  1  inch  or  so,  a 
powerful  stream  of  white  sparks,  mem1  or  less  painful,  will  be  received. 

The  Interrupter. — A  continuous  current  or  one1  of  uniform  strength 
and  passing  in  eme1  direction  doe's  not  induce  a  current  in  a  neighboring 
wire.  It  is  necessary  that  the  current  should  be  made1  and  broken  at 
regular  intervals  and  with  greater  or  less  rapidity.  For  most  purposes 
the  rate  of  interruption  is  from  1200  to  2000  times  a  minute1.  The1 
form  of  apparatus  employed  varies  according  to  the  strength  of  the1 
current  and  the1  rapidity  required. 

Tin  Electro  magnetic  Vibrating  Interrupter  or  Hammer  Interrupter. — 
This  is  the  form  almost  always  employed  in  connection  with  faradic 
coils,  and  often  with  Kuhmkorff  coils.  It  may  be  used  with  .r-ray 
coils,  but  some  other  type  is  usually  selecte-el  when  heavy  currents  are 
to  be  employed.  It  consists  of  a  disk  of  iron  or  stee1!  fastened  upon  a 
strip  of  spring  metal,  which  te'nds  to  keep  the  hammer  pressed  lightly 
against  a  point  of  contact  from  which  the1  hammer  is  drawn  away  bv 
the  attraction  of  an  electromagnet.  The1  moment  the  contact  is  broken, 
the  current  ceases  to  flow  through  the  winding  of  the  electromagnet 
and  the  hammeT  springs  back  to  the  point  of  contact  again.  Kach 
cycle  consists  in  making  the1  current,  attraction  by  the1  electromagnet, 
breaking  the1  current,  cessation  of  attrae'tion  by  the1  electromagnet, 
and  making  the  current  again.  \Yhen  properly  adjusted,  such  an 
interrupter  begins  to  act  the1  moment  the  current  is  turner!  on  by  closing 
a  switch  or  by  immersing  the  elements  in  a  battery.  If  it  does  not  start 
at  once,  it  may  be  because  the  point  is  not  in  contact  with  the  hammer 
or  because  the  point  is  screwed  so  far  forward  that  even  the  pull  of  the 
electromagnet  will  not  separate  the  hammer  from  the1  point  of  contact 
and  break  the  current.  This  adjustment  must  be  made  to  enable  it 
to  act  properly,  but  even  then  the'  interrupter  will  sometimes  fail  to 
start  spontaneously,  and  will  require  a  touch  with  the1  finger  to  star; 


142  MEDICAL    ELECTRICITY    AND    RONTGKN    KAYS 

it.  This  may  properly  bo  regarded  as  a  structural  defect  which  should 
be  remedied  by  the  manufacturer.  The  points  of  contact  on  the 
hammer  and  on  the  surface  opposed  to  it  should  be  of  some  metal 
which  does  not  easily  oxidize,  either  from  exposure  to  the  air  or  under 
the  action  of  an  electric  spark. 

The  metal  strip  on  which  the  hammer  is  fastened  may  be  so  made 
that  even  when  the  current  is  entirely  disconnected  from  the  apparatus 
it  will  vibrate  back  and  forth  for  some  time  before  coming  to  rest.  In 
this  case  the  rate  of  interruption  will  be  determined  to  a  great  extent  by 
the  periodicity  of  the  spring  itself,  just  as  the  periodicity  of  the  hair- 
spring of  a  watch  keeps  it  vibrating  in  seconds  exactly  the  same  from 
the  time  that  the  watch  is  wound  up  until  it  runs  down.  In  the  case 
ot  the  watch,  the  force  exerted  by  the  mainspring  varies  tremendously 
during  this  time,  but  the  periodicity  of  the  hair-spring's  vibrations 
continues  the  same.  An  interrupter  generally  has  a  periodicity  of  its 
own.  which  can  be  varied  so  as  to  produce  rapid  or  slow  interruptions 
in  the  primary  current.  This  adjustment  is  sometimes  made  by  turning 
a  screw  which  advances  the  point  of  contact  and  makes  the  to-and-fro 
path  of  the  hammer  and  its  periodicity  shorter. 

The  Ribbon  Interrupter. — To  secure  a  very  great  range  of  variation 
in  periodicity  the  vibrating  hammer  is  fastened  to  a  steel  band  which 
is  held  tightly  at  its  two  ends,  and  the  tension  upon  which  can  bo  varied 
by  turning  a  thumb-screw.  Its  rate  of  vibration  can  be  changed  from 
a  rate  so  low  as  to  give  a  coarse,  rough,  bass  sound,  by  which  the  inter- 
ruptions can  almost  be  counted,  to  a  fine,  almost  inaudible  sound, 
representing  almost  the  highest  note  perceptible  by  the  human  ear. 
The  secondary  current,  especially  its  physiologic  effects,  are  greatly 
influenced  by  the  rate  and  character  of  the  interruptions  in  the  primary 
cm-rent. 

Atonic  or  A /n  riof/ic  Interrupters. — Gaiffo  and  other  manufacturers 
nf  ./--ray  coils  have  fitted  them  with  hammer  interrupters  in  which  the 


linger.  This  is  accomplished  by  having  the  pressure  of  the  spring 
strong  enough  to  prevent  a  rebound  when  the  hammer  is  pressed  back 
against  the  point  of  contact  from  which  it  has  been  separated  and 
allowed  to  fly  back.  Of  course,  the  electromagnet  must  be  strong 
enough  to  overcome  the  pressure  of  the  spring  and  draw  the  hammer 
away  from  the  point  of  contact.  Such  an  interrupter  is  designed  to  be 
ifoverned  by  onlv  two  forces,  the  attraction  of  the  electromagnet 
acting  as  long  as  the  current  flows  through  its  winding  and  the  pressure 
nl  the  spring.  The  latter  is  so  adjusted  that  at  no  part  of  its  path  is 
oils  rebound  trom  the  point  ot  contact.  The  spring 
in  to  vibrate  back  and  forth.  The  point  of  contact 
rward  that  the  spring  is  never  allowed  to  reach  its 
neutral  point  :  it  is  alwavs  making  pressure  in  the  same  direction,  never 
in  the  opposite  or  rebound  direction.  This  is  thought  to  be  more 
absolutely  harmonious  with  the  current  and  to  give  a  better  character 
of  interruption  for  ./'-ray  coils  than  those  with  an  inherent  periodicity. 
1 1  n  in  an  r  infi  rru pit  i  s  may  be  act  uated  bv  t  he  iron  core  of  the  primary 
coil  itself,  and  the  contact  which  1  hev  make  and  break  may  control  the 
primarv  current.  Thi-  is  almost  ahvavs  the  arrangement  in  faradic 
coils,  and  i<  sometimes  used  in  small  .r-rav  coils.  Another  arrangement 


DYNAMIC    ELECTRICITY 


143 


the  primary  circuit  by  its  mechanic  to-and-fro  motion;  but  it  is  at  a 
distance  from  the  primary  coil,  and  its  own  motion  is  not  due  to  the 
magnetization  and  demagnetization  of  the  con;  of  the  primary  coil. 
A  separate  electromagnet  actuated  by  a  much  weaker  current  sets  this 
interrupter  in  motion,  and  it  mechanically  makes  and  breaks  the  heavy 
current  for  the  primary  coil  just  as  if  it  were  moved  back  and  forth  by 
any  other  force.  The  weaker  current  belonging  to  the  interrupter  and 
its  electromagnet  is  easily  and  uniformly  interrupted,  and  the  uniform 
to-and-fro  motion  of  the  hammer  is  more  assured  than  if  it  depended 
upon  the  complete  interruption  of  as  powerful  a  current  as  that  of  the 
primary  of  an  .r-ray  coil.  The  hammer  goes  back  and  forth,  regularly 
touching  and  withdrawing  from  the  point  of  contact  where  the  primary 
current  is  made  and  broken;  and  this  regular  motion  is  independent  of 
the  primary  current,  and  goes  right  on,  even  if  an  arc  forms  temporarily 
across  the  space  and  the  primary  current  thereby  fails  to  break  for  the 
time  being. 

The    Wheel    Ti/pe    of    Electromagnetic    Interrupter. — This    is    shown 
in  the  appended  diagram  (Fig.  113).       The  contact  is  broken  at  c  by 


Fig.  113. — Wheel  interrupter. 


the  mechanic  motion  of  the  hammer,  and  this  is  produced  by  the 
pressure  and  relaxation  of  the  eccentric,  e.  The  latter  is  fastened 
to  a  revolving  wheel  whose  four  spokes  are  permanent  magnets.  When 
the  contact  is  made  at  c,  the  current  flows  and  the  core  of  the  primary 
coil  becomes  a  powerful  electromagnet,  exerting  an  attraction  for  the 
magnet  whose  opposite  pole  is  near  it.  and  a  repulsion  for  the  magnet 
whose  nearest  end  has  the  same  polarity  as  that  existing  at  that  end 
of  the  iron  core.  These  forces  start  the  wheel  in  rotation,  and  the 
eccentric  presses  against  the  spring  metal  support  of  the  hammer, 
breaking  the  contact  at  c.  Momentum  carries  the  wheel  around  to 
a  position  where  the  contact  is  again  made  and  where  the  same 
magnetic  forces  again  become  operative,  giving  the  wheel  a  fresh 
impetus  in  the  same  direction.  It  is  a  simplified  type  of  electric 
motor,  and  produces  a  very  rapid  and  uniform  interruption  of  the 
current.  The  currents  used  for  faradic  coils  are  not  strong  enough  to 
require  such  an  elaborate  interrupter,  and  it  will  not  work  well  with 
the  heaviest  currents  used  for  .r-ray  work.  It  has  proved  useful, 
however,  in  apparatus  for  the  production  of  high-frequency  cm-rents. 
and  one  such  interrupter  is  reported  to  give  an  excellent  output  of 


144 


MEDICAL    ELECTRICITY    AND    HOXTCKN    KAYS 


100  to  o()0  millianipcres.  \vith  a  primary  current  of   1   ampere  or  con- 
siderably less. 

All  the  interrupters  described  above  depend  upon  the  alternate 
magnetization  and  demagnetization  of  an  electromagnet,  these  caus- 
ing to-and-fro  movements  in  the  armature  which  mechanically  make 
and  break  the  current  in  the  electromagnet  and  in  the  primary  coil. 
These  two  are  sometimes  the  same  and  sometimes  separate  coils  of 
wire. 

Mi  cl/iitn'r  Interrupters. — There  are  also  interrupters  which  make  and 
break  the  primary  current  by  means  of  the  motion  of  one  of  the  points 
of  contact,  this  motion  being  produced  by  a  motor  of  some  kind  which 
acts  quite  independently  of  the  current  which  it  is  designed  to  control. 
The  arc  which  tends  to  form  when  the  points  of  contact  are  separated 
would  allow  the  current  to  continue  to  flow  across  that  space.  It  is 
usually  suppressed  in  these  interrupters  by  having  the  points  of  contact 
below  the  surface  of  a  liquid,  such  as  alcohol.  The  contacts  may  be 
like  those  of  the  revolving  commutator  of  a  motor  or  dynamo,  or  the 
contact  mav  be  between  liquid  metallic  mercury  and  some  solid  metal. 

Mercury  interrupters  are  of  two  types-  - 
the  mercury  dip  and  mercury  jet  inter- 
rupters. All  these  except  the  Leduc 
interrupter  are  of  use  chiefly  for  high- 
frequency  currents  and  the  x-ray,  and  are 
described  in  the  section  upon  the  latter 
subject  (p.  854). 

Leduc  s  Lnlcrniptcr.  —  Our  diagram 
(Fig.  114)  shows  Stcphan  Leduc 's  modifi- 
cation of  the  Contremoulin  interrupter. 
It  consists  in  making  one  of  the  brushes 
movable,  and  thus  enables  one  to  regu- 
late the  fraction  of  the  total  period  of 
the  interrupter,  during  which  the  two 
brushes  shall  be  in  contact  with  the 
same  pair  of  metal  strips.  This  fraction 

can  be  varied  from  a  very  small  fraction  I,,,1,,,,),  up  to  the  full  time 
represented  by  the  length  of  the  metal  strip.  \o  current  can  pass 
through  the  interrupter  when  either  brush  is  in  contact  with  the  insula- 
ting substance  or  when  the  brushes  are  in  contact  with  metal  strips 
belonging  to  different  pairs,  and  therefore  having  no  metallic  connection 
with  ea<-h  other.  To  produce  a  contact  lasting  only  a  very  small  trac- 
tion of  a  period  the  movable  brush  is  placed  in  such  a  position  that  the 
one  metal  strip  only  begin.-  to  touch  it  as  the  opposite  strip  is  just 
leaving  the  other  brush.  To  produce  a  cont  act  last  ing  tor  the  max  in  mm 
time  the  brushes  are  placed  directly  opposite  each  other,  and  in  this 
position  "tie  brush  i-  in  contact  with  a  certain  metal  strip  the  entire 
time  that  the  other  bm-h  is  in  contact  with  the  connected  metal  strip. 
Intermediate  positions  of  the  movable  brush  allow  the  current  to  pass 
during  a  larg'T  or  -mailer  fraction  of  each  period.  Knowing  the 
fraction  "f  each  period  that  the  current  is  flowing  and  the  tension  ot 
the  current  as  shown  \>v  a  voltmeter  in  shunt,  we  can  calculate  the 
ia-sing  through  the  patient  or  the  apparatus, 
lie  galvanometer,  which  is  called  a  dead-beat 
e  circuit  will  show  the  ouantitv  of  electricity 


Insulation 


DYNAMIC    ELECTRICITY  I4o 

passing,  this  being  indicated  in  milliamperes  and  being  actually  the 
average  rate  of  flow  of  the  current,  including  the  portions  of  time  when 
the  current  is  interrupted.  If  the  rate  of  revolution  is  rapid,  tin- 
periods  occupy  a  shorter  length  of  time,  but  there  are  more  of  them  in 
a  minute  and  the  current  strength  remains  the  same.  Very  great 
variations  in  the  rapidity  of  the  interruptions  produce  changes  in  the 
physiologic  effects,  even  though  they  do  not  change  the  average  current 
strength. 

In  regulating  the  fraction  of  each  period  occupied  by  the  duration  of 
the  contact  we  may  depend  upon  the  graduated  scale  marked  upon  the 
apparatus.  But  if  this  is  defective  or  is  absent,  the  adjustment  becomes 
a  matter  of  calculation.  In  order  to  have  a  contact  T'0  of  each  period, 
close  the  circuit  with  a  non-polarized  resistance  and  raise  the  tension 
by  adjusting  the  volt  controller,  for  instance,  until  the  milliamperemeter 
shows,  for  example,  10  milliamperes.  Start  the  interrupter  arid  shift 
the  movable  brush  to  such  a  position  that  the  milliamperemeter  shows 
that  a  current  of  I  milliarnpere  is  passing.  Really  this  means  that  a 
current  of  10  milliamperes  is  passing  for  T^  of  the  time,  and  conse- 
quently Y'^  of  each  period.  The  proper  position  of  the  movable  handle 
for  other  fractional  currents  is  found  in  a  similar  manner.  Stephan 
Ledtic  has  estimated  the  time  during  which  the  current  passes  even 
to  so  small  a  fraction  as  ^6000  °^  a  seconcl  °f  time. 

Liquid  or  Electrolytic  Interrupters. — These  are  used  chiefly  in  x-ray 
and  high-frequency  work,  and  are  described  on  p.  852. 

The  Secondary  Coil. — This  is  a  coil  containing  a  very  large  number 
of  turns  of  very  fine  wire  which  is  very  carefully  insulated.  The  wire 
itself  in  an  x-ray  coil  is  No.  36;  looks  as  fine  as  a  hair;  is  wrapped  with 
silk;  and  is  coated  with  melted  paraffin  after  being  wound  in  the  sec- 
ondary coil.  The  secondary  coil  in  a  12-inch  x-ray  coil  contains  40 
miles  of  wire.  The  secondary,  coil  in  a  faradic  battery  contains  from 
1000  to  8000  feet,  the  larger  number  of  feet  corresponding  to  the  faradic 
coil  with  fine  wire,  the  1000  feet  corresponding  to  the  faradic  coil  with 
coarse  wire  in  the  works  of  some  authors. 

In  a  great  Rnhmkorff  coil,  made  by  Apps  for  Spottiswood,  there  were 
280  miles  of  wire.  It  gave  a  42-inch  spark  through  the  air  when 
actuated  by  a  voltaic  battery  of  30  Grove  cells.  Since  the  discovery 
of  the  .r-ray,  coils  of  this  power  have  frequently  been  made. 

Every  time  the  cm-rent  is  made  or  begins  to  flow  in  the  primary 
coil  a  current  is  induced  in  the  secondary  coil.  This  is  momentary, 
and  flows  in  a  contrary  direction  to  that  of  the  current  in  the  primary 
coil.  When  the  primary  current  is  broken  or  ceases  to  flow,  a  current 
is  induced  in  the  secondary  coil  which  is  momentary,  and  in  the  same 
direction  as  the  current  which  has  just  ceased  to  flow  in  the  primary 
coil.  The  break  current  is  direct  and  produces  a  more  powerful  dis- 
charge across  an  air-space  or  through  a  vacuum  tube  than  does  the 
make  current.  The  latter  is  what  is  spoken  of  as  the  inverse  discharge 
in  .r-ray  work.  There  is  thus  a  distinct  polarity  to  the  secondary 
current.  Although  it  flows  first  in  one  direction  and  then  in  the  other 
the  greatest  effect  is  produced  during  the  periods  when  a  certain  pole 
of  the  coil  is  the  positive.  Tin's  can  be  seen  in  .r-ray  or  in  any  other 
vacuum  tube  work,  and  a  difference  can  even  be  seen  in  the  sparks  pass- 
ing across  from  one  pole  of  the  secondary  roil  to  the  other.  The  negative 
end  of  the  spark  is  much  brighter  and  of  a  violet-white  color,  while  the 


14t> 


MEDICAL    ELECTRICITY    AND    ROXTGKX    KAYS 


positive  end  is  not  so  brilliant  and  has  a  more  reddish  tinge.  And  then, 
again,  the  successive  sparks,  each  of  which  can  be  seen  as  a  complete 
more  or  less  zig-zag  line,  are  more  divergent  at  the  positive  than  at  the 
negative  pole.  A  photograph  made  of  a  series  of  sparks  passing  between 
the  two  similar  blunt  metal  terminals  of  a  12-inch  x-ray  coil  shows  that 
the  majority  of  the  sparks  start  from  the  same  spot  on  the  positive  ter- 
minal and  pursue  the  same  path  for  a  certain  distance,  then  separate, 
to  converge  again  on  approaching  the  negative  pole,  but  no  two  paths 
coalesce,  and  they  all  reach  different  parts  of  the  surface  of  the  nega- 
tive terminal.  The  result  is  entirely  different,  however,  when  one  elec- 
trode is  conical  and  the  other  is  a  flat  metal  plate  (Fig.  115).  What 
has  been  said,  however,  is  not  intended  as  a  statement  that  the  spark 
originates  at  one  pole  and  terminates  in  the  other  pole.  It  is  probable 
that  the  discharge  takes  place  simultaneously  from  both  terminals. 

By  the  negative  pole  of  the  secondary  coil  is  meant  the  one  which  is 
the  negative  pole  during  the  break  or  direct  discharge.  This  is  the 
pole  which  is  always  connected  with  the  cathode  or  negative  electrode 
of  an  .r-ray  tube,  and  an  important  part  of  .r-ray  technic  is  the  sup- 
pression of  the  inverse  discharge.  In  another  part  of  the  book  (p.  709) 
will  be  found  a  description  of  the  means  adopted  to  prevent  the  inverse 


discharge  from  passing  through  the  .r-ray  tube  in  sufficient  amount  to 
be  a  disturbing  factor.  The  only  useful  current  supplied  to  an  .r-ray 
tube  is  the  direct  discharge  which  is  produced  in  the  secondary  coil  by 
the  break  of  the  primary  current.  The  inverse  discharge  which  occurs 
alternately  with  the  direct  discharge  is  produced  by  the  make  of  the 
primary  current.  During  the  inverse  discharge  the  polarity  of  the 
secondary  coil  is  just  opposite  to  what  it  was  during  the  direct  dis- 
charge, and  the  current  may  be  said  to  pass  through  the  .r-ray  tube  in 
ing  direction.  I'nder  normal  conditions  the  .r-ray  tube  appears 

into  a  brilliantly  fluorescent  half  in  front  of  the  plane  of  the 
disk  or  ant  icathode,  and  a  dark  hemisphere  behind  that 

When  there  is  a  {iood  deal  of  inverse  discharge,  but  still  con- 
siderable direct  discharge,  the  whole  tube  appears  lighted  by  a  streaky 
or  irregular  greenish  fluorescence.  There  is  sometimes  a  great  deal  of 
inverse  discharge  and  -carcely  any  direct  discharge.  This  condition 
i-  indicated  by  the  absence  of  the  illuminated  hemisphere  in  front  ot 
the  plane  of  the  ant  icat  hode  in  place  of  which  there  is  a  dark  hemisphere 
with  only  one  bright  given  >pot  where  the  cathode  ray.  starting  from 
(•very  spot  on  the  platinum  surface,  strikes  the  glass  wall  of  the  tube 
and  (generates  .r-ravs.  The  half  of  t  he  tube  which  should  be  dark  is  irreg- 


DYNAMIC    KLECTR1CITY  147 

i 

ularly  fluorescent  from  similar  cathode  rays  originating  from  other  parts 
of  the  antieathode  or  from  the  accessory  anode.  The  tube  in  such  a 
condition  looks  like  a  tube  connected  with  the  wrong  poles  of  the  coil. 
We  cannot  secure  any  useful  .r-ray  from  a  tube  of  the  usual  model 
during  the  make  or  inverse  discharge  of  the  coil.  The  best  that  can 
be  done  is  to  prevent  any  considerable  part  of  this  inverse  discharge; 
from  passing  through  the  tube,  and  thus  to  secure  the  greatest  efficiency 
during  the  alternate  periods  when  the  direct  discharge  is  passing  through 
the  tube.  The  importance  of  the  subject  lies  in  the  fact  that  any 
conditions  which  permit  the  passage  of  the  inverse  discharge  through 
the  tube  obstruct  to  about  the  same  extent  the  passage  of  the  direct 
discharge  and  reduce  the  output  of  the  tube.  In  the  extreme  case 
mentioned  a  few  lines  back,  and  which  the  author  can  duplicate  experi- 
mentally at  any  time,  no  effective  .r-ray  at  all  is  produced.  The  wear 
and  tear  upon  the  tube  are  excessive. 

The  icirc  in  the  secondary  coil  is  almost  as  fine  as  a  hair,  and  the 
object  of  this  is  to  bring  every  turn  of  it  as  close  as  possible  to  the 
primary  coil,  so  as  to  cut  as  many  of  the  expanding  and  contracting 
lines  of  force  as  possible.  It  is  not  sufficient  that  the  secondary  coil 
should  be  outside  of  the  primary  coil,  it  must  also  be  very  close  to  it. 
The  secondary  winding  for  one  of  the  smaller  induction  coils  for  faradic 
treatment  is  not  a  difficult  matter.  The  difference  in  potential  between 
one  end  of  the  long  secondary  wire  and  the  other  is  not  sufficient  to 
produce  a  spark  of  any  appreciable  length,  and  so  the  ordinary  methods 
of  insulation  arc  sufficient.  The  insulated  wire  is  wound  upon  a  reel, 
just  as  thread  is  wound  upon  a  spool,  one  layer  after  another,  all  con- 
tinuous and  all  in  the  same  direction.  The  insulated  beginning  arid 
end  of  the  wire  are  both  left  outside,'  where  they  can  be  connected  with 
the  binding  posts,  to  which  may  be  attached  the  conducting  cords 
leading  to  the  patient.  These  binding  posts  arc  of  metal,  and  are 
fastened  upon  an  insulated  base  of  varnished  wood,  hard  rubber,  ivory, 
indurated  fiber,  marble,  or  slate.  The  regulation  of  the  strength  of  the  cur- 
rent passing  to  the  patient  is  sometimes  secured  by  changing  the  primary 
current,  by  changing  the  resistance,  or  by  changing  the  number  of  cells 
if  a  voltaic  battery  is  used.  It  is  much  better,  however,  to  have  the 
primary  and  secondary  coils  so  mounted  that  their  relative1  position 
may  be  varied.  The  strongest  secondary  current  is  produced  when 
the  secondary  coil  entirely  covers  the  primary  coil,  and  as  the  primary 
coil  is  drawn  out  from  the  lumen  of  the  secondary  coil,  the  secondary 
current  becomes  gradually  weaker.  Measuring  the  distance  in  cen- 
timeters that  the  movable1  coil  is  displaced  enables  one  to  use  a  mathe- 
matic  number  in  recording  the  strength  of  the  current  applied  to  the 
patient.  The  quality  of  the  secondary  current  varies  according  to  the 
number  of  feet  of  wire  in  the  secondary  coil  and  the  rapidity  of  the  inter- 
ruptions, and  it  will  be  seen  (p.  4(>7)  that  very  different  physiologic  and 
therapeutic  effects  may  be  obtained  by  means  of  such  variations. 

The  Knft-iroii  core  has  always  been  considered  an  important  part  ot 
an  induction  coil.  Its  effect  is  to  increase  the  strength  of  the  secondary 
current  by  adding  its  own  expanding  and  contracting  lines  ot  force  to 
those1  of  the  primary  coil.  It  is  best  made  of  soft-iron  wires  in  a  straight 
parallel  bundle'.  These  acquire  and  lose  their  magnetism  when  the 
primary  current  is  made  and  broken  much  more1  promptly  and  com- 


148  MEDICAL    ELECTRICITY    AND    HONTGEN    KAYS 

pletely  than  a  solid  bar  of  the  same  weight.  The  strength  of  the  sec- 
ondary current  is  very  considerably  augmented.  As  already  stated 
p.  134),  the  core  is  not  a  necessity,  and  recent  observations  indicate 
that  for  faradic  treatments  the  current  has  a  pleasanter  quality  if 
there  is  no  core1. 

The  Condenser.— This  is  not  required  with  a  liquid  interrupter 
of  the  C'aldwell-Simon  or  \\  clinch  types,  but  is  required  with  many  of 
the  vibrating  or  other  mechanic  interrupters.  It  is  made  for  an 
induction  coil,  of  a  great  many  layers  of  tin  foil  separated  by  mica 
or  paper,  and  is  usually  concealed  in  the  wooden  base  of  the  coil.  The 
sheets  of  tin-foil  are  in  two  separate  sets,  and  fit  together  like  the  two 
halves  of  a  pack  of  cards  when  one  half  is  held  in  each  hand  and  the 
cards  are  being  shuffled  by  pressing  them  together  in  an  interlocking 
fashion.  All  the  sheets  of  one  half  are  fastened  together  by  one  metal 
clamp,  and  they  really  form  a  single  large  metal  coating  or  armature  of 
a  condenser  in  which  the  other  armature  is  formed  by  the  other  sheets 
of  tin-foil,  and  the  glass  jar  or  plate  is  represented  by  the  many  sheets 
of  mica  or  paper  which  prevent  any  contact  between  the  sheets  of 
tin-foil  in  one  set  with  those  in  the  other  set.  The  condenser  is  designed 
to  prevent  excessive  sparking  at  the  interrupter,  and  in  this  way  to 
produce  a  sharper  and  better  break  of  the  primary  current  than  would 
be  possible  if  the  primary  current  continued  to  flow  as  an  arc  across  the 
space  after  the  contact  was  broken.  The  condenser  takes  up  or  absorbs 
the  extra  current,  which  results  from  self-induction  in  the  primary  coil 
at  the  moment  that  the  circuit  is  broken.  We  have  already  seen 
(p.  135)  that  this  extra  current  is  of  high  tension,  will  spark  across  a 
considerable  air  gap,  and  has  in  this  way  some  of  the  properties  of 
static  electricity.  It  very  naturally'occurs  that  when  the  two  armatures 
of  the  condenser  are  connected  with  the  ends  of  the  wire  forming  the 
primary  coil  in  which  such  a  cm-rent  is  generated,  the  condenser  becomes 
charged.  The  effect  at  that  moment  is  the  same  as  when  the  inner 
armature  of  a  Leyden  jar  is  brought  in  contact  with  one  prime  con- 
ductor of  a  static  machine,  while  the  outer  coating  touches  the  other 
prime  conductor.  In  the  case  of  the  induction  coil  the  charge  received 
by  the  condenser  produces  Just  Sl)  much  less  tendency  to  sparking  at  the 
interrupter.  The  high  electromotive  force  generated  at  the  time  of 
the  bre;ik  of  the  circuit  ceases,  and  the  condenser  becomes  discharged 
a>  its  outer  ;md  inner  coats  are  connected  bv  the  primary  wire.  It  is 
then  readv  to  perform  its  function  at  the  next  break  in  the  primary 
current,  i  See  also  pages  242,  243.) 

I.iouid  or  ''electrolytic"  interrupters  do  not  require  any  condenser 
to  suppress  the  spark  when  the  current  is  broken.  'I  here  is  a  tremen- 
doiis  difference  between  the  conduct  ivit  V  through  a  complete  liquid 
path  and  the  resistance  offered  by  the  mass  <>]  incandescent  vapor 
which  H  irenerated  at  the  narrowest  part  of  the  liquid  path.  '1  his 
results  in  a  practically  complete  obstruction  to  the  flow  of  even  the 
high-voltage  extra  current  occurring  from  .-elf-induction  in  the 
t irima  rv  circuit  at  i  he  t  ime  it  is  broken. 

The  general  arrangement  of  an  induction  coil  fed  by  a.  voltaic 

battery  i-  shown  in  Fr_r.  1  1»».      //  i-  the  voltaic  battery.      I1' mm  one  pole 

•   1 1  ••  battery  a  wire  leads  i  lirect  ly  to  />.  where  it   is  c<  >nt  in  nous  with  the 

prin  ;trv  cnil   of  wire.      The  other  end   of  the  orimarv  wire  is  shown   in 


DYNAMIC    ELECTRICITY 


149 


h  H 


the  diagram  at  the  opposite  end  of  the  coil,  but  in  actual  practice  both 
ends  of  the  primary  wire  are  usually  brought  to  the  same  end  of  the 
coil.  The  other  end  of  the  primary  wire  leads  to  the  base  of  the  vibra- 
ting hummer,  //,  which,  when  no  current  is  being  used,  is  pressed  lightly 
against  the  contact  />•  by  the  springiness  of  its  metal  stem.  From  /;  a 
wire  leads  to  the  other  pole  of  the  battery  when  the  switch,  til,  is  closed. 
Wires  lead  from  the  two  ends  of  the  primary  wire  to  the  two  armatures 
of  the  condenser,  c.  When  the  current  is  turned  on  by  changing  the 
switch  from  dm  to  dl,  the  current  passes  through  k  to  h,  and  through  the 
stem  of  /;,  and  a  connecting  wire  to  one  end  of  the  primary,  through 
the  primary  wire,  and  thence  to  the  other  pole  of  the  battery.  The 
soft-iron  core  /  becomes  a  powerful  electromagnet  and  attracts  the 
hammer  h  away  from  the  contact  k  and  breaks  the  current.  This 
break  is  accompanied  by  the 
induction  of  a  high-tension 
extra  current  in  the  primary 
which  surges  out  through  the 
conducting  wires,  most  of  it 
going  to  the  condenser  where 
such  large  electric  capacity  is 
provided.  Set  screws  not 
shown  in  the  diagram  regu- 
late the  pressure  of  the  ham- 
mer upon  the  contact  while  at 
rest,  and  also  the  distance  that 
it  can  go  when  drawn  away 
from  it.  In  no  case  is  it  neces- 
sary for  it  to  touch  the  iron 
core.  Motion  toward  the  mag- 
net i/ed  iron  core  is  in  a  direction  to  break  the  current,  and  no  electric 
contact  is  required  to  be  made  at  that  end  of  its  path. 

The  secondary  coil  has  its  two  terminals  leading  out  and  connected 
with  binding  posts.  The  smaller  induction  coils  are  called  faradic  coils, 
and  conduct  ing  cords  lead  from  the  two  terminals  to  electrodes,  which  are 
applied  to  two  different  parts  of  the  patient.  In  the  case  of  the  very  large 
Ruhmkorff  coils,  suitable  for  .r-rav  work,  a  spark  or  an  actual  flame 
may  pass  across  between  the  two  terminals,  when  a  full  current  is 
turned  on,  unless  the  two  terminals  are  connected  with  an  .r-ray  tube 
oi1  some  other  apparatus  through  which  the  secondary  discharge  is 
conducted.  This  is  because  of  t  he  enormously  high  voltage  or  difference 
in  potential  between  the  electric  charges  nt  the  two  ends  of  the  forty 
miles  of  wire  forming  the  secondary  coil.  The  charge  is  developed 
thousands  of  times  a  minute:  its  duration  is  only  momentary,  but 
during  its  continuance  there  is  an  almost  irresistible  tendency  for  the 
two  opposite  forms  of  electricity,  posit  ive  and  negat  ive.  to  rush  toget  her 
and  become  neutralized.  The  tension  at  the  two  poles  or  terminals 
i-  so  great  that  a  succession  of  sparks  will  pass  across  the  12  inches 
of  air-space  which  separate  them,  although  every  inch  requires  a 
voltage  variously  estimated  at  from  10. 000  to  .'JO.OOO.  If  not  quite 
enough  current  is  turned  on  to  produce  a  spark  across  that  distance 
between  the  poles,  a  brush  discharge  of  violet  light,  accompanied  by 
a  crackling  sound,  will  take  place  into  the  air  surrounding  the  two 


I Iffllft 


Fiji.    116.       (irnrral    arrangement 
turn    coil    fed    hv    a    voltaic 


of    an    induo- 
battery. 


Lo(J  MKDH'AL    KLK(  TRICITY    AX!)    RONTGEN    RAYS 

poll's.  Ill  cither  case  a  spark  will  fly  to  the  finder  or  any  other  conductor 
brought  near  cither  of  the  poles,  and  the  same  is  true  even  when  the 
discharge  is  passing  through  some  apparatus  to  which  both  poles  arc 
connected.  This  property  possessed  by  high-tension  electricity  of 
sparking  across  an  air-space  or  through  any  other  insulating  substance 
to  a  neighboring  conductor  has  to  be  constantly  borne  in  mind  in  the 
therapeutic  and  also  in  the  industrial  application  of  electricity.  It  is 
the  cause  ot  most  of  the  accidents  occurring  to  human  beings  in  power- 
houses and  elsewhere,  and  is  often  the  cause  of  explosions  and  fires 
occurring  in  connection  with  the  use  of  electricity  for  light  and  power. 
It  must  be  guarded  against  in  the  construction  and  manipulation  of 
eleetrothcrapeutie  apparatus,  to  prevent  puncturing  .r-rav  tubes  and 
burning  out  induction  coils.  Fortunately,  there  is  nothing  dangerous 
about  the  sparks  or  shocks  which  may  occur  from  handling  electro- 
therapeutic  apparatus.  At  the  same  time  they  are  disagreeable,  and 
should  be  prevented  by  care  in  manipulation. 

The  difference  in  potential  between  any  two  parts  of  tin.1  secondary 
wire  varies  according  to  their  relative  position  in  the  scries  of  turns 
that  make  up  the  coil.  Imagining  it  for  the  purpose  of  explanation  as 
a  single  spiral  layer  of  wire  wrapped  around  a  very  large  glass  cylinder, 
the  difference  in  potential  between  the  wire  at  the  two  ends  might 
be  !")(). 000  volts,  or  sufficient  to  spark  across  an  air-space  of  15 
inches.  The  difference  in  potential  between  any  two  consecutive  turns, 
on  the  contrary,  .would  be  very  small.  Roughly  speaking,  it  would  be 
the  total  voltage  of  the  coil  divided  by  the  number  of  turns.  In  the 
same  way  the  difference  in  potential  between  any  part  of  the  wire  is 
equal  to  the  same  fraction  of  the  total  voltage  that  the  number  of  turns 
of  wire  between  these  two  parts  forms  of  the  total  number  of  turns. 
If  the  two  ends  of  the  wire  are  bent  around,  so  as  to  be  brought 
within  12  inches  of  each  other,  a  spark  will  pass  between  them  even 
through  the  air.  Bui  it  is  quite  different  with  two  consecutive  turns 
of  wire,  between  which  the  difference  in  potential  may  be  so  slight  that 
an  ordinary  silk  wrapping  will  prevent  any  passage  of  electricity  from 
one  to  the  other,  even  if  they  are  wrapped  one  on  to])  of  the  other. 
The  difference  in  relative  position  has  reference  to  the  distance  between 
them  following  the  continuous  wire  from  end  to  end.  It  has  no  refer- 
ence to  the  physical  position  of  the  turns.  They  might  be  wound  in 
such  a  way  in  making  the  coil  that  two  turns  lying  in  physical  contact 
with  each  other  might  be  portions  of  wire  many  thousands  of  turns 
apart  if  the  wire  were  followed.  The  difference  in  potential  between 
the  extreme  ends  of  the  secondary  wire  is  so  great  that  the  terminals 
cannot  both  be  placed  at  the  same  end  of  the  coil.  If  they  were,  there 
would  be  sparking  across  from  one  to  the  other  and  also  from  the  poles 
to  intervening  turns  of  wire,  and  one  of  the  latter  sparks  would  ruin  the 
coil  bv  destroying  the  insulation  of  the  wire  at  that  place  in  the  coil. 
For  the  same  reason  the  secondary  coil  cannot  be  wound  in  successive 
layers,  each  continuous  from  one  end  of  the  reel  to  the  other,  like  a 
-pool  of  thread.  With  such  an  arrangement  portions  of  1  he  wire  many 
thousands  of  turns  apart  would  be  placed  in  such  close  physical  prox- 
imity that  a  disruptive  discharge  would  pass  from  one  such  turn  to 
am  it  her  and  rum  the  coil. 


DYNAMIC    ELECTRICITY 


151 


The  form  of  winding  which  has  been  adopted  for  rr-ray  coils  consists 
in  having  the  wire  in  several  flat  spirals,  separated  from  each  other  by 
disks  of  hard  rubber.  Each  flat  spiral  contains  consecutive  turns,  and 
between  the  beginning  and  end  of  that  section  there  is  not  enough 
difference  in  potential  to  break  through  the  insulation  of  silk  and  wax 
and  cause  a  short  circuit.  The  additional  insulation  afforded  by  the 
hard-rubber  disk  is  sufficient  to  prevent  a  discharge  occurring  between 
one  section  and  the  next  adjacent  one,  in  spite  of  the  considerable 
difference  in  potential.  Sections  near  the  ends  of  the  coil  have  an.  enor- 
mous difference  in  potential,  but  a  discharge  is  prevented  from  occur- 
ring, first,  by  the  physical  distance  between  them;  second,  by  the 
insulating  properties  of  the  mass  of  wax  in  which  the  whole  coil  has 
been  boiled  and  is  embedded,  and,  third,  by  the  insulation  of  the 
numerous  hard-rubber  disks.  The  whole  coil  is  in  the1  form  of  a  hollow 
cylinder  built  up  over  a  tube  of  micanite,  a  compound  of  mica  and 
shellac,  which  forms  the  best  possible1  insulator.  This  shemld  be1  long 
and  thick  enough  to  prevent  a  discharge  passing  from  one  enel  of  the 
secondary  coil  to  the  primary  e-oil,  and  through  that  to  the  other  end  of 
the  see-emdary  coil.  The1  resistance  in  the  primary  coil  is  very  small, 
and  its  position  inside  the  secondary  coil  ami  extending  from  one'  enel 
of  it  te>  the  either  wemlel  make  it  offer  a  short  e-ircuit  for  the  secondary 
discharge  if  the  primary  coil  were1  insufficiently  insulated.  The  com- 
])leiteid  .r-ray  coil  consists  e>f  a  secomlary  coil  and  a  primary  coil  which 
has  no  connection  with  the  secondary  coil,  but  lie's  loeisely  in  the  micanite1 
tube  lining  the  secomlary  cenl.  The  primary  coil  may  be  pushed  in 


Fi<r.    117. — A    correct    winding,  but   imprac- 
ticable. 


or  out  or  may  be  removed  entirely.  The  secemdary  coil  is  sometimes 
incaseel  in  marble1  ami  sometimes  in  hard  rubber,  and  these  are  desirable 
safeguards  against  the  passage1  of  a  discharge  te>  semie1  intermediate 
part  of  the  secondary  coil  from  the  discharging  rods  often  connected 
with  its  two  pole's.  Sue-h  a  spark  would  ruin  the  coil. 

in  building  a  coil  up  in  disks,  like  sections  of  wire  wound  between 
hard-rubber  disks,  it  is  necessary  that  the-  wire  in  each  see-tion  shall  be 
continuous  with  that  in  the1  adjae-ent  sections,  and  that  the1  elirection 
of  the  cunvnt  shall  be  the  same1  in  all  the  seM-tions.  For  instance1, 
looking  at  the  end  of  the  coil,  if  the1  cunvnt  in  the  first  section  pusses 
in  the1  dirertion  of  the1  hands  of  a  wate-h  at  a  e'ertain  period,  then  the1 
cunvnt  in  all  the  other  sections  must  pass  in  the1  direction  of  the1  hands 
ot  a  wate'h  at  the1  same1  period  of  time1.  The1  connection  between  the1 
first  section  and  the1  see-emd  may  be1  made1  by  passing  the  e'entral  e-nd  of 
the  first  spiral  wire  through  a  hole1  in  the  hard-rubber  partition  near  the 
central  (Mid  of  the  adjacent  spiral  wire.  When  it  conies  to  joining  the1 


Io2  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

other  or  outer  end  of  the  second  spiral,  it  is  passed  through  the  outer 
part  of  the  next  hard-rubber  partition  and  soldered  to  the  outer  end 
of  the  next  spiral.  So  the  different  sections  which  have  been  wound 
separately  are  united  into  a  single  continuous  wire,  but  then1  is  a  very 
necessary  precaution  to  be  taken  in  securing  the  proper  direction  of 
the  current  in  each  of  them.  If  they  are  all  strung  along  on  the  axis 
of  the  coil,  so  that  they  are  all,  for  example,  right-handed  spirals,  as 
in  Fig.  118,  .1  and  />',  the  current  in  each  section  would  be  Mowing 
in  an  opposite  direction  from  that  of  the  adjacent  sections.  The  reason 
is  very  simple:  if  the  current  in  one  is  flowing  from  the  outer  end  of 
the  spiral  wire  to  its  inner  end,  it  is  continued  in  the  next  section  from 
the  inner  to  the  outer  end  of  the  spiral  wire:  and  if  they  are  all  light- 
handed  spirals,  the  current  in  one  is  in  an  opposite  direction  to  that 
in  the  next  spiral.  The  current  in  each  section  is  not  merely  flowing 
through  the  wire,  but  is  actually  excited  in  that  section;  and  in  the 
bad  arrangement  shown  in  Fig.  118,  it  would  completely  neutralize 
and  arrest  the  current  excited  in  the  opposite  direction  in  the  adjacent 
sect  ion. 

Fig.  119  shows  the  proper  arrangement  of  the  various  sections. 
There  are  right-handed  and  left-handed  spirals  alternately,  and  the 
current  flows  in  the  same  direction  in  all.  The  picture  is  purely  dia- 
grammatic. Kach  spiral  really  is  a  disk-like  mass  containing  thousands 
of  feet  of  wire,  and  its  flat  surface  is  separated  from  that  of  the  adjacent 
section  by  only  the  thickness  of  a  hard-rubber  disk.  The  arrows  show 
the  direction  of  the  current  at  the  time  when  the  terminal  near  .1  is 
the  negative  and  that  near  ('  the  positive  pole  of  the  secondary  coil. 


The  arrows  would  all  have  to  be  reversed  to  show  the  direction  of  the 
current  during  the  period  when  .1  is  t  he  positive  and  ('  the  negative  pole. 
In  the  last  lew  paragraphs  we  have  spoken  ol  tin-  direction  ot  the  cur- 
rent, and  n  might  have  been  called  the  direction  of  the  electromotive 
force.  The  make  or,  especially,  t  he  break  of  t  he  primary  current  induces 
an  electromotive  force  m  every  individual  turn  in  every  section  ot  the 
secondary  (ioil;  and  if  the  latter  is  correctly  constructed,  all  these 
electromotive  forces  are  added  together  in  -cries  and  the  rcM.lt  in 
voltage  i-  perfectly  enormous,  just  as  it  would  be  il  a  tremendous  num- 
ber of  voltaic  cells  were  set  up  in  series.  The  current  which  will  >park 
across  between  the  terminals  or  which  will  pass  through  a  vacuum 
tube  i  if  ot  her  appa  rai  us  connected  with  the  two  poles  is  ot  great  voltage 
and  of  very  -mall  amperaife.  The  power  possessed  by  the  discharge 
from  the  secondary  coil  is  expressed  in  watts,  one  watt  being  equal  to 
1  ampejv  of  current  at  !  volt  of  potential.  The  total  number  of  watts 
equal-  the  number  of  amperes  multiplied  by  the  number  of  volts,  and 


DYNAMIC    ELECTRICITY  IO.5 

no  more  power  can  come  out  of  an  induction  coil  than  was  put  into  it. 
The  intake,  in  a  typical  case,  may  be  20  amperes  at  100  volts,  making 
2000  watts,  and  the  result  ing  secondary  current  may  have  a  voltage  of 
C>0, 000.  Supposing  all  the  power  of  the  2  kilowatts  in  the  primary 
current  were  converted  into  power  as  the  secondary  current,  then  we 
might  have  the  following  equation:  (H),000,  the  number  of  volts  in 
the  secondary  current,  multiplied  by  the  number  of  amperes  in  the 
secondary  current,  equals  2000,  the  number  of  watts,  60, 000  (x  amperes) 
=  2000;  x  =  (io'ooo ;  x  =  j§J5  amperes;  x  =  33  milliamperes.  These 33 rnilli- 
amperes  would  be  found  to  be  the  intensity  of  the  secondary  current,  ex- 
cept for  the  fact  that  the  primary  and  secondary  currents  are  interrupted, 
and  that  the  secondary  current  is  of  an  alternating  character  with  wide1 
variations  in  intensity.  The  number  of  watts  as  a  maximum  must  be  re- 
duced materially,  because  the  induction  coil  wastes  some  of  the  power  put 
into  it.  There  are  certain  lines  of  force1  leaving  the  two  ends  of  the  iron 
con1  and  arching  over  from  one  end  to  the  other  which  are  not  cut  by 
the  secondary  turns  of  wire.  This  is  true  of  any  aeroferric  type  of 
magnet.  It  will  be  seen  on  another  page1  that  this  loss  of  power  is 
prevented  in  transformers  of  the  closed  magnetic  ring  or  complete1  ferric- 
type.  There1  is  some  loss  of  power  e>r  reduction  in  the  number  of  watts 
yieleleel  by  an  induction  e'oil  on  account  of  the1  ohmic  resistance  of  200,000 
feet  of  fine1  wire1.  This  loss  woulel  be1  evident  as  overheating  of  the1 
secondary  coil,  except  for  the  fact  that  the1  ohmic  or  frictional  resistance 
is  in  proportion  to  the1  intensity  or  amperage1  of  the  current,  and  not  at 
all  to  the1  pressure  or  voltage.  A  certain  number  of  watts  of  electric 
power  in  the1  form  of  a  current  of  60, 000  volts  and  33  milliamperes  will 
pass  through  a  line1  wire  without  perceptible  heating,  whereas  the1  same 
2000  watts  of  power  as  a  current  of  10  volts  and  200  amperes  would  heat 
the1  wire  white1  hot  and  }>erhaps  vaporize1  it.  The  ohmic  resistance  in 
the1  secondary  coil  is  great  enough,  however,  to  make  a  material  dif- 
ference between  the  number  of  watts  applied  to  and  the  number  yielded 
by  an  ineluction  coil.  But  this  output  or  secondary  current  has  wide 
variations  in  intensity  at  different  parts  of  each  of  its  2000  to  10,000 
cye-les  a  minute.  At  a  certain  instant  then1  may  be  a  powerful  current 
in  eine1  direction:  at  another  instant  no  current  may  flow,  and  at  another 
instant  1  he-re-  may  be1  a  powerful  current  in  the1  opposite1  direction.  A 
milliamperemeter  in  which  each  unit  indie-ates  a  milliampere  (joVc 
ampere-)  may  be1  useel  to  measure  the1  stivngth  of  the1  secondary  current. 
It  may  be1  connected  with  one  pole  of  the  e-oil  and  with  the1  .r-ray  tube 
and  register  in  this  way  the1  intensity  or  ampe'rage  of  the1  current  pass- 
ing tlmmgh  the  tube-.  This  will  appear  to  be  from  0  or  even  a  minus 
quantity  up  1o  2,  4.  (>,  X,  or  even  15  to  30  niilliamperes.  The1  milli- 
anipeTe-inele-r  may  be  of  the  D'Arsonval  type,  and  depend  upon  the1 
directional  effect  of  a  current  passing  through  a  coil  which  is  in  close1 
relation  with  a  powerful  magnet.  In  such  a  case1  the  neeellc1  upon  the1 
dial  indicates  in  a  geneTal  way  the  average  strength  and  direction  of  the1 
secondary  current.  The1  alteTiial  ions  from  the  dhvct  to  the1  inverse- 
discharge  are  so  rapid  that  they  are1  not  shown  by  such  an  instrument. 
Such  a  ine-te1!'  may  indicate  0  when  the  .r-ray  tube1  is  giving  a  radiance 
by  which  a  moderately  gooel  picture1  may  be1  made1,  and  this  would 
indicate1  that  the  inverse1  discharge1  was  ee[iial  to  the  eliivct.  The  value 
of  this  type1  of  milliamperemeter  as  a  guide1  to  the1  propeT  application 
»it  the  .r-ray  is  consiele'ivel  at  another  place  (p.  859  >. 


154  MKDICAL    ELECTRICITY    AND    RONTGEX    RAYS 

A  hot  u't'ir  mi II (amperemeter  between  one1  pole  of  the  coil  and  the  x-ray 
tube  gives  a  reading  of  several  niilliamperes,  and  is  not  influenced  by 
the  amount  of  inverse  discharge.  because  that  has  the  same  heating 
effect  as  if  it  were  in  the  right  direction.  In  an  experiment  by  the 
author  a  large  hot  wire  milliainperemeter  intended  to  measure  high- 
frequency  and  high-tension  currents  up  to  650  niilliamperes  intensity 
was  connected  with  one  pole  of  a  12-inch  .r-ray  coil.  A  wire  fastened 
to  the  other  binding-post  of  the  milliamperemeter  reached  to  within  a 
few  inches  of  the  other  pole  of  the  coil.  The  110  volts  direct  current  of 
the  incandescent  electric  lighting  system,  afte-r  passing  through  a 
\Yehnelt  interrupter,  produced  a  current  of  6  amperes  in  the  primary 
coil.  A  regular  ilame  passed  across  the  4  inches  separating  one  pole 
of  the  coil  from  the  wire  leading  to  the  milliamperemeter.  The  length 
of  the  spark  showed  a  voltage  of  40,000  and  the  milliamperemeter  in- 
dicated an  intensity  of  150  niilliamperes.  Here  there  was  an  apparent 
power  of  (iOOO  watts  produced  by  the  application  of  about  GOO  watts,  a 
considerable  part  of  which  was  certainly  expended  in  overcoming  the 
resistance  in  the 'liquid  interrupter.  The  apparent  discrepancy  is  due 
to  the  fact  that  the  voltage  is  greatly  reduced  during  the  passage  of 
the  continuous  flame,  just  as  100  volts  will  maintain  an  electric  arc 
1  inch  long  which  it  would  take  10,000  volts  to  originate. 

Spottiswood's  Induction  Coil. — This  was  a  great  coil  made  in 
ls~6.  and  some  of  the  facts  in  regard  to  it  will  be  of  interest.  It  was 
4s  inches  long  and  20  inches  in  diameter.  The  primary  coil  was  of 
copper  wire.  -^  inch  in  diameter  and  2000  feet  long.  It  made  1334 
turns  in  six  layers.  The  secondary  coil  contained  240  miles  of  wire  in 
four  different  sections:  2  of  wire  T •/,-„-  inch  in  diameter,  and  two  of  a  little 
larger  wire:  the  total  number  of  turns  being  H42.000.  A  battery  of 
5  galvanic  cells  produced  a  2S-inch  spark;  10  cells  gave  a  36-inch 
spark,  and  HO  cells  a  spark  40  inches  long. 

IRON"    CORKS 

Outside  DianiPtPr  I-piiRth.  Weight, 

of  Ciirp.  Inches.  Inches.  Pounds. 

:i..")(i  4  \  ti7 

:-!.si  41  1)2 

PRIMARY    COILS 

H.  W.  (',.  I. riiirth,  Resistance,  Weight.        Conductivity, 

Yard-.  Ohms.  Pounds.  Per  Cent. 

i:;  tn  in  •_>.:;  .">.">  '.»:; 

i:;  :•()!  0.211  si 


SI'.COXDARY    Coll. 


I. (-Mirth, 
Miles. 


DYNAMIC    KLKCTKK'ITY  !.")"> 

CONDENSER 

12(>  sheets  tin-foil,  IS  inchesX'S',  inches,  separated  by  two  thicknesses  of   varni.-hed 
jiaper,  .011   thick,    111  inches  XH  indies  surface. 

BATTERY 

.">    one-(iuart    drove    cells,    plates  t>|     inches   /   ','>   inches,    <*ave  2S-inch   spark    with 

smaller  primary. 
10  one-([uart  drove  cells,  plate.-  (>[  inches  X  '•>  inches,  <:ave  o.Vinch  spark  with 

.-mailer  primary. 
:>()  one-quart  drove  cells,  plates  (>}  inches  X  -'i  inches,  »;ave  42-inch  spark  with 

smaller  primary. 

The  secondary  discharge  is  seen,  from  the  above  examples,  to  con- 
sist of  a  succession  of  waves  in  alternate  directions,  of  extremely  high 
voltage  and  of  an  amperage  much  greater  than  is  produced  by  a  static 
machine  and  much  greater  than  could  be  maintained  by  the  same 
power  as  a  continuous  current  of  the  same  voltage. 

The  Undulatory  Nature  of  the  Induced  Current.  —A  tracing 
made  by  means  of  Duddell's  oscillograph  shows  that  the  current  from 
an  induction  coil  usually  consists  of  a  series  of  separate  curves,  (Mich 
beginning  suddenlv  at  a  distance  from  the  neutral  line  and  descending 


\         \         \         \          \         \ 

Fif:.  120. — Secondary  currents  from  induction  coil  with  iron  core. 

or  ascending  more  or  less  gradually  toward  it.  Fig.  120  shows  the  kind 
of  a  curve  made  by  the  secondary  current  of  an  induction  coil  with  a 
short  secondary  winding  and  a  soft-iron  core.  The  break  currents  are 
seen  below  the  neutral  line  and  the  make  currents  above  it.  In  the  case 
illustrated  the  make  currents  are  not  so  powerful,  but  last  much  longer 
than  the  break  currents.  The  latter  are  of  short  duration  and  of 
abrupt  character.  According  to  the  observations  of  Lewis  Jones,1  such 
a  current  produces  a  much  more  disagreeable  effect  in  causing  muscular 


V       V      V      V       V     V 

~r.    ~?~  ~r  ~r.   ~T 

idg.  121.      Secondary   currents  from  coil  without  iron  core. 

contraction  than  one  illustrated  in  Fig.  121  produced  by  the  same 
coil  after  withdrawing  the  soft-iron  core.  Kven  this,  according  to 
Lewis  Jones,  is  not  ideal;  there  is  too  great  a  difference  between  the 
make  and  break  currents,  and  a  still  greater  uniformity  would  be  better 
tor  diagnostic  purposes.  This  uniformity  can  hardly  be  obtained 
troni  an  induction  coil,  but  is  produced  by  the  right  character  of  inter- 
ruptions in  a  continuous  current  and  in  a  circuit  with  little  self-induc- 
tion. He  uses  this  current,  which  is  considered  on  another  page  4(,)2i 
under  the  name  of  the  interrupted  voltaic  current  instead  of  the  faradic 
current,  for  diagnosis  and  treatment. 

'British  Medical  Journal.  October  s,  I'.HH. 


150 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


Before  leaving  the  subject  it  will  he  best  to  reproduce  two  more  of 
Lewis  .Jones'  graphic  representations.  Fiji.  122  shows  the  character 
of  an  interrupted  and  reversed  voltaic  current  in  a  circuit  with  little 
-elf-induction.  For  a  certain  period  of  time,  the  most  favorable  being 
j ,/,,,,  of  a  second,  the  current  strength  is  uniform  and  in  the  same  direc- 
tion. Then  a  change  occurs  almost  instantaneously  and  a  similar 
period  follows  with  the  current  in  the  opposite  direction.  With  a  proper 


Fii:.  !_'_'. — Lcduc  currents.     Interrupted  and  reversed  voltaic  currents  in  a  circuit   with 

little  inductance. 

;ntriTUpter  the  frequency  of  these  cycles  and  the  duration  of  the  suc- 
cessive currents  may  be  measured  and  regulated. 

The  influence  of  self-induction  in  -uch  a  circuit  is  shown  in  Fig.  12o. 
where  a  few  hundred  turns  of  wire  are  introduced  in  the  circuit.  The 
result  is  that  the  current  strength  gradually  increases  from  zero  until 
its  increase  is  cut  short  by  the  break  and  reversal  of  the  current.  The 
same  sort  of  a  curve  in  the  opposite  direction  represents  the  current 


during  the  alternate  period.     There  is  scarcely  a  demonstrable  interval 


b<  'tween   the  two  periods  <>f   current    flow.       This    form    of  current   als 


could  lie  used  as  a  substitute  for  the    faradic  current    from    an    induc- 


Fit:.  124  sho\vs  the  primary  and  secondary  currents  in  an  induction 


a  long  secondary  wire  and  without   an  iron  core.       1  he  upper 


line  shows  the  primary  current   with  its  abrupt    rise  when  the  contact 


i_'!.  —('urn  lit.-  in    an  induction  coil    with  a    lone    Fccondarv  \\irc  and    no    inn 


is  made,  its  continuance  at  a  certain  strength  up  to  the  instant  that 
the  current  i-  broken,  and  its  sudden  fall  at  thai  lime.  The  lower 
diagram  shows  th'1  secondary  current:  the  curved  lines,  the  make 
currents  above  and  tin-  break  currents  below  the  heavy  neutral  line. 
The  differences  between  the  two  different  currents  in  the  secondary 
coil  are  important.  They  are  in  opposite  directions.  Thev  attain 


DYNAMIC    ELECTRICITY  1  •")" 

a  maximum  almost  instantly  when  the  primary  current  is  made  or 
broken,  and  very  soon  cease.  The  make  current  is  not  so  strong  a.-s 
the  break  current,  but  lasts  longer  and  dies  out  somewhat  more  grad- 
ually than  the  break  current.  In  this  particular  experiment  the  make 
current  of  the  secondary  coil  lasted  -r('J(T  of  a  second,  and  the  break 
current  s-J--jj-  of  a  second,  the  frequency  of  the  interruptions  in  the 
primary  current  \vas  SO  times  a  second. 

It  is  necessary  to  have  a  separate  electromagnet  if  a  hammer  inter- 
rupter is  used  with  an  induction  coil  which  possesses  no  iron  core.  The 
ribbon  vibrators  as  used  in  faradic  coils,  and  usually  actuated  by  the 
magnetized  iron  core,  are  equally  desirable  for  separate  use  in  this  case. 
It  is  noteworthy,  however,  that  no  vibrating  interrupter  is  perfect. 
The\"  all  fail  occasionally  to  make  a  perfect  electric  contact,  and  this 
may  occur  at  irregular  intervals  and  produce  a  disagreeable  effect  upon 
the  patient. 

The  duration  of  flow  of  each  secondary  current  should  be  about 
Yiv'ffo  °f  a  second  to  produce  the  best  effect  in  exciting  muscular  con- 
tractions. 

Fig.  125  shows  the  primary  and  secondary  currents  in  the  same  coil 
with  a  long  secondary  winding,  but  with  a  soft-iron  core  introduced 
into  the  primary  coil.  The  primary  current  shows  the  effect  of  the 


I-'itr.  12").— Currents  in   an  induction  coil  with    a   long  secondary  wire  and  an  iron  core: 
P,  Primary;  .S,  secondary. 

additional  self-induction.  There  is  a  choke  effect  when  the  current 
is  made,  and  as  this  induced  countereleetromotive  force'  in  the  primary 
coil  disappears,  the  primary  current  gets  stronger  and  stronger  right 
up  to  the  time  that  the  contact  is  broken.  The  effect  of  this  upon,  the 
secondary  current,  which  is  the  current  applied  to  the  patient,  is  shown 
to  be  very  marked.  The  make  current  attains  its  maximum  less  sud- 
denly and  dies  out  very  gradually,  lasting  right  up  to  the  breaking  ot 
the  contact.  The  break  current  is  a  great  deal  stronger  than  without 
an  iron  core,  and  is  of  about  twice  as  long  duration.  This  is  quite 
characteristic  of  the  current  from  a  faradic  coil,  and  according  to 
several  observers  it  occasions  more  discomfort  in  the  production  ot 
muscular  contraction  in  diagnosis  or  treatment  than  does  the  current 
from  the  coil  without  a  core,  or  than  a  simple  low-tension  current 
interrupted  rapidlv  with  or  without  alternation-.  Besides  being  more 
or  less  uncomfortable,  it  is  very  difficult  to  make  any  accurate  measure- 
ment ot  the  current  passing  through  the  patient.  Tracings  like  those 
in  the  preceding  paragraphs  are  to  be  made  only  with  the  most  elaborate 
apparatus  and  preparation.  Practically,  one  is  limited  in  usimr  an 
ordinary  faradic  coil  to  depend  upon  the  sound  of  the  interrupter  for 
an  indication  of  the  rate  at  which  the  successive  currents  occur,  and 
upon  the  length  »f  the  secondary  coil  and  its  distance  from  the  primary 
c<'il  to  indicate  the  .-treiunh  of  the  secondary  currents.  Xo  measure- 


MEDICAL    ELECTRICITY    AND    RONTCKN    RAYS 

ment  and  no  adjustment  arc  practicable1  at  the  time  of  the  treatment 
of  the  strength  of  each  impulse  of  the  secondary  curient.  and  of  its  dura- 
tion as  compared  with  the  pauses  between  the  make  and  break  currents: 
in  other  words,  of  its  actual  duration  and  the  fraction  of  each  period 
occupied  by  it. 

The  hammer  or  vibrating  interrupter  is  another  source  of  imper- 
fection in  the  ordinary  faradic  coil:  a  tracing  of  the  currents  will  show 
that  many  of  the  contacts  are  ineffectual,  and  that  there  is  a  corre- 
<p< Hiding  irregularity  in  the  secondary  current.  Of  course,  a  better 
interrupter  may  l>e  employed  for  the  primary  current,  such  as  one 
which  the  present  author  calls  the  commutator  type  of  interrupter. 
The  Leduc  interrupter  (p.  144)  is  an  example,  and  this  will 
correct  the  irregularity  in  the  current:  but  it  yields  such  a  desirable 
interrupted  voltaic  current  that  the  induction  coil  would  not  be  required 
at  all.  The  effect  of  the  iron  core  may  be  minimized  by  slipping  a  metal 
tube  over  it.  This  cuts  the  expanding  and  contracting  lines  of  force 
as  the  core  becomes  magnetized  and  demagnetized,  and  whatever 
energy  is  consumed  in  producing  electric  currents  in  the  metal  tube 
loses  its  direct  effect  upon  the  secondary  current. 


l_'ii.  —  F:ir:tilic    coiN:    A.  Ordinary  arrangement.     H.   1  lelmholt  x's  arrangement. 


VS  fiirner or  Neet's  hammer    interrupter    fur    Bois-Revinond    slide    furadic    coil,    t\\o    ditter- 


iit    arrangements:  >'/.  Standard:  >',   Ilelmholtz  column:   Km.  electromagnet;  P.  pnmar\ 


and  .Stv-.  upper  and   lower  contact  screws;  Sp,   .-pring;  Aux.   arc., 


Helmholtz's  Faradic  Coil. — This  is  an  arrangement  by  means  of 
which  the  secondary  currents  in  each  direction  are  made  approximately 
equal.  In  the  ordinary  arrangement  the  make  current  is  weak,  impaired 
bv  the  self-induction  in  the  primary  coil,  which  causes  the  primary 
make  current  to  increase  less  abruptly  than  it  otherwise  would,  and 
hence  to  be  less  effective  in  inducing  a  secondary  current.  And  in  the 
ordinary  arrangement  the  self-induced  extra  current  in  the  primary 
c»il  ;it  the  brc;ik  is  immediately  stopped  by  the  fact  that  the  circuit 
is  "pen.  It  may  produce  a  spark  at  the  interrupter,  but  it  has  little 
effect  upon  the  primary  current,  which  ceases  quite  abruptly  and 
produces  a  strong  "break"  current  in  the  secondary.  These  conditions 
are  shown  in  the  diagram  I-'iir.  !'T.  The  heavy  line  shows  the  actual 
(•nurse  of  •  .  ry  current  as  modified  bv  the  influence  of  the  extra 

current  almost  exdu-ivelv  at  the  make.  Kxcept  for  the  latter  the 
primary  current  would  have  followed  the  rectangular  path  marked 
"  de-ii  lerat  u  n  i  "  at  the  ma  ke. 

The  ordinary  arrangement  of  the  vibrating  interrupter  of  a  faradic 


DYNAMIC    ELECTRICITY 


159 


coil  is  shown  in  Fig.  126,  A.  Starting  from  the  zinc  polo  of  the  voltaic 
coll,  the.  current  finds  only  a  single  path  through  the  standard  St,  the 
spring  Sp,  the  contact  screw  $crl,  the  primary  coil  p,  the  electromagnet 
£//?  (the  primary  coil  and  the  electromagnet  may  he  the  same  or  may 
be  separate  and  in  series),  and  back  to  the  other  pole  of  the  voltaic  cell. 
When  the  current  is  made  by  contact  with  the  screw  Her1,  there  is  but 
a  single  conducting  path,  as  above  described,  and  when  the  contact  at 


primary 




uinse  of  the  cur 


^Secondary 


break  current" 


Fig.  127.  —  Faradic  currents  with  ordinary  Wagner  hammer  interrupter. 

that  point  is  broken  by  the  attraction  of  the  electromagnet  for  the 
hammer,  the  current  is  completely  cut,  off. 

In  Fig.  126,  B,  it  will  be  seen,  on  the  contrary,  that  at  this  stage  the 
primary  coil  is  short-circuited,  and  this  permits  of  the  full  establishment 
of  the  break  extra  current  in  the  primary.  At  this  stage  the  primary 
coil  is  disconnected  from  the  zinc  pole  of  the  battery.  The  extra 
current  circulates  in  a  complete  circuit,  consisting  of  the  primary  coil, 
the  electromagnet,  the  Helmholtz  column  and  the  wire  leading  to  it, 


primary 


Secondary 


make    currenr  break  current 

Fig.  112S. — With  Ilehnholtz's  arrangement. 

the  spring  of  the  interrupter  and  the  auxiliary  circuit  through  the 
contact  screw  .Scr1  to  the  primarv  coil.  Through  this  circuit  the 
battery  current  is  completely  cut  off.  but  the  extra  current  flows  in  the 
same  direction,  and  this  reduces  the  secondary  current  produced  by 
the  break  in  the  same  way  and  to  about  the  same  extent  as  is  the  ease 
with  the  make  secondary  current. 

To  bo  accurate,   the  current  through  the  primary  coil   is  increased 


ItiO 


MKDH  AL    KLF.CTKK  ITY    AND    KONT<iKN     KAYS 


or  diminished,  not  made  or  broken,  l>y  the  Hclniholtx  typo  of  electro- 
magnetic interrupter;  and  while  the  induced  currents  are  approximately 
equal.  thi<  is  accomplished  l>y  reducing  the  l>reak  secondary  current  to 
al>out  the  strength  of  that  occurring  at  the  make  (Fig.  1'2'.>).  The 
induct  i  vi-  etTect  is.  t  here  fore,  a  weak  one,  and  to  secure  t  he  usual  farad  if 
strength  of  application  it  is  necessary  to  use  a  primary  battery  yielding 
seven  or  eitfht  volts.  An  extra  resistance  in  the  battery  circuit  will  gen- 
erally be  found  necessary  with  this  type  of  interrupter. 

There  is  a  urnwim:  belief  that  the  faradic  current,  with  its  high- 
tension  discharge,  is  not  so  good  even  in  its  own  particular  field  of  an 
excitoniotor  as  i  he  rapidly  interrupted  voltaic  cm-rent.  The  faradic 
coil,  however,  is  of  so  simple  a-nd  inexpensive  a  construction  and  is 
operated  by  so  small  a  supply  of  current  that  it  will  long  continue  in 


!_".».  —  I'-ual  type  of  primary  waves  in  faradic  coil. 


use  where  an  inexpensive  and  readily  portable  apparatus  is  required 
TO  -imply  excite  muscular  contraction,  as  in  the  treatment  of  paralysis. 

(  MM-  of  Lewis  .lone.-'  experiments  shows  the  effect  of  great  frequency 
of  interruption  in  a  faradic  coil  with  an  iron  core,  and  consequently  a 
loiiii  duration  to  the  make  and  break  currents  in  the  secondary  coil. 
This  is  illustrated  in  Fig.  lij(),  where  we  see  the  make  current  suddenly 
cease  and  change  to  the  break  current.  The  break  current  is  "treading 
upon  the  heels  of  the  make  current."  The  lower  line  in  this  diagram 
repre-ent-  the  make  current  and  the  upper  line  the  break  secondary  or 
iin  luce.  1  current . 

The  importance  of  the  character  of  the  interruptions  in  any  current 

.  i.-  applied  directly  to  the  human  body  lies  in  the  fact  that  muscular 

factions  d"  not   occur  durimr  the  passage  of  a  continuous  current. 


in  t  In'  -iTondary  roil  \vhrn  tlirrr  '.ire  too  rapid  intrrnnitioi 


rm  and   flow-  in  one  dire.  lion.      They  are  u>uallv 

in   tin-  strength  or  direct  ii  MI  of  the  current   or  hv 

inii  the  current,   and   in   this  way   remind  one  of  the 

n -h  '  1 1  i-ii  '•  ••  . :  : '  nts  are  induced  in  one  mil  ol  v  ire  b\  current  s 

•     •    '     •       .      \\  it !    in  ten  ipi  eil  current  s  t  he  if  real  esi  effect  iii  excit  iim 

'     1)1   i-  produced  when   the  current    flows  during  a  larif>' 

Thi-    ha-    been    tested    by    Lewis    .1'  mes,  v,  ho 

of   L'L'    volt-    \va-    I  he   weakest    thai    would   excite 

\  hen  t  he  current   HI  i  wed  "til  v   ,,,',-,,,  of  a  period,  or 

•    '  '  '    '     .   cula  r  ci  nit  fact  ii  >n  i!  the  IMI  rrent 

;  lerii  >d.  or  1 1.1  H  1 1  -econd.      l-'uri  her  ci  in<i,  |eru- 
:  ia  rt   of  t  he  bonk   i  p.    l'.r_' 


DYNAMIC    KLKCTKICITV 


1G1 


THE    CHARACTER    OF    THE    ALTERNATING    ELECTRIC-LIGHT    CURRENT 

The  current  flows  with  its  full  strength  in  one  direction  for  about  halt' 
the  time,  and  with  its  full  strength  in  the  other  direction  for  about  hall' 
the  time.  The  time  which  elapses  between  the  beginning  of  one  How 
in  a  given  direction  and  the  beginning  of  the  next  now  in  the  same 
direction  is  called  a  cycle.  A  100-cycle  alternating  current  is  one  which 
makes  100  complete  cycles  every  second.  The  (iO-cvcle  current  is  one 


100-cycle  alternating  current. 

very  commonly  employed.  Each  cycle  includes  a  certain  time  of  flow. 
first  in  one  direction  and  then  in  the  other;  and  at  the  end  of  each  a 
time  of  change  to  the  opposite  direction.  This  transition  is  made  by 
gradations  which,  of  course1,  are1  exceedingly  rapid.  The  current  through 
an  alternating  electric-light  circuit  of  100  incandescent  lamps  woulel 
make1  a  tracing  like  that  in  Fig.  132.  During  the  time  represented  by 
the1  line  <i-c,  and  which  is  about  -^T)  second,  the  electric  current  is  flowing 
in  one  direction  with  a  maxi- 
mum intensity  of  50  amperes. 
Another  way  of  stating  this  is 
that  during  this  time  the1  quan- 
tity of  electricity  passing- 
through  the  wire1  is  at  a  maxi- 
mum rate1  of  50  coulombs  per 


second.     The 
pressing    the 


latter  way  of  ex- 
rate1   of   flow 


Fig.  132.  —  100-pycle  alternating  current  from 
mplete    cycle.      There    are    1(H) 
:  adapted   from   Houston. 


flow  of  water  during  the  rise1  and   fall 
econd  during   which  the  electricity  is  flowing 


(>H-    O     to     b    IS    one 

ables  us  to  compare  the  alter-  cyclcs  in  a  M 
nating  electric  current  with  the 
of   the1   tide.      The 

in  one1  direction  at  a  maximum  rate1  of  50  coulombs  a  second  corresponds 
to  the1  six  hours  or  so  during  whie'h  the1  tiele1  is  running  up  stream  and 
the  water  is  flowing  at  a  maximum  rate  of  say  50.000  gallons  an  hour. 
At  f  in  Fig.  132  the  elevtric  current  has  become  reduevd  to  zero,  and  then 
begins  to  incivase1  with  eemal  rapidity  to  a  strength  of  10.  20,  30,  40.  and 
50  amperes,  which  it  ivaches  at  d.  From  this  point  to  c  the1  curves!  line 
represents  ._M'MI  seconel,  during  which  the  effective  or  we1  might  say.  les- 
technie-ally,  average1  intensity  of  the  cunvnt  is  about  37  amperes,  and 
at  the'  end  of  this  time1  a  change  occurs  by  which  the  eliree-tion  of  the 
current  is  again  ivverseul,  ami  at  b  we1  have1  completed  one1  eye-le  of  this 
11 


11)2  MKDIl  AL    KI.KCTKHITY    AND    HO.NTCJKN     HAYS 

alternating  current.  This  is  a  sinusoidal  current,  so  culled  because 
its  uraphic  curve  makes  what  is  icnucd  in  uvomctry  a  sine  wave. 
As  in  the  effect  produced  in  various  therapeutic  applications,  these 
transitions  are  so  abrupt  that  the  current  may  he  regarded  as  completely 
interrupted  as  well  as  reversed  at  each  alternation.  For  our  purpose, 
then,  this  current  may  he  represented  as  in  Fitr.  loo.  by  a  series  of  dis- 
connected horizontal  lines,  alternately  above  and  below  the  neutral 
line.  Fach  line,  ,/  <•  or  <l  r,  represents  a  current  of  the  full  strength, 
•")<>  amperes  in  this  particular  case,  for  ._,,',,,  second  in  one  direction  or 
the  other,  n  <•  and  '/  <  constitute  the  two  parts  of  the  complete  cycle 
a  to  l>.  A  current  of  the  character  indicated  in  Fig.  loo  is  an  extremely 
effective  one.  both  in  inducing  current s  in  other  wires  and  also  in  pro- 
ducing phy-ioloiiic  effects.  I  ts  potency  in  t  he  latter  particular  makes  it 
a  much  more  daimerous  current  to  handle  at  hi<ih  voltages  than  the  direct 
current  of  the  same  voltage,  but  when  the  alternations  are  more  rapid 
'halt  .~>OOO  times  a  secojid  the  current  ceases  to  produce  muscular  con- 
traction and  acquires  the  properties  associated  with  high-frequency 
current  s. 


'/At. 
d 


/•  rt  ijin  nr//  i  if  fin  nlli  runt!  ni)  rum  nt  i-  1  he  number  of  cycles  completed 
in  a  second,  o'O  cycles  are  <ienerally  u>ed  for  liuht  iny  and  powei1.  20  cycles 
for  power  transmission.  For  !i_uhtitm.  anything  as  slow  as  2")  cycles 
w< mid  cau.-e  visible  flickering. 

l:"icfn'i  1,1/1,1  nj  nn  nit,  riKif/'riii  cum  ill  i-  that  value  in  amperes  which 

1    produce    the   same    heating   effect    as    will    the   same   intensity    (or 

amperes     ot    direct    current.      Alternating   current    meters   indicate   the 

ive  value.      The  act  ual  value  of  r  he  alternat  inn;  current  is.  of  course, 

v  chanirinir,  and   too   rapidly   for  the  eye   to  follow  anv  meter 

\\  Inch  iin  lic.ated  it . 

i  {  effect  ive  value 

M  '/./•'  m  inn  i  nl in  iij  an  nltcrnnti tui  current  =  - 

0.707 

Forms  Under  Which  the  Alternating  Current  is  Used  in  Medi- 
cine,     i:.  i'  -  '  •:  ;Lr:!i:d  unmodified  form  it  i-  used  for  diagnostic  iilumina- 
i  '.'•' .  elect  i'ic  bat  hs,  and  lor  1  he  induct  ion  o;  hitih -tension 
frequency  current.-,   and   for  the  induct  ion 
•  '.'-  lor  cautery  purposes,  and  to  run  electric  motors 
:    -        • .  -••-. 

''    vari<  iiis  •  levin  s  <  >r.  rat  h(  r,  i1  -  >  \    av  be 

'•'•''    :  '  .  ••  -a  direi-t    current,  a  sinusoidal  current,  a  polv- 


Alternating     Current     Transformers,    Step-up    and    Step-down 

Transformers.     T!.»-  al'<  n     !  in::  elect  i  ir-liirht  current ,  wit  h  itschaii"'e 


DYNAMIC    ELECTRICITY 


1(13 


from,  say,  f>0  amperes  in  one  direction  to  50  amperes  in  the  other 
direction  every  ._,',,,  second,  is  an  ideal  one  to  induce  secondary  current-. 
This  is  all  the  more  true  because  it  has  been  found  that  no  accessory 
apparatus  is  required,  simply  a  primary  coil  and  a  secondary  coil,  both 
surrounding  a  soft-iron  core.  The  principle  is  the  same  as  in  the  in- 
duction coil,  but  the  variations  in  the  current  are  supplied  ready  made 
by  the  dynamo,  and  no  interrupter  is  needed  and  no  condenser  or 
other  contrivances,  such  as  are  necessary  in  the  case  of  an  induction 
coil.  The  secondary  currents  are  of  any  desired  voltage,  dependent 
upon  the  number  of  turns  in  the  two  coils.  If  there  are  twice  as  many 
turns  of  wire  in  the  secondary  coil  as  in  the  primary,  the  voltage  of  the 
'secondary  current  will  be  twice  that  of  the  primary  current.  Or,  if 
the  secondary  has  only  ,  ^  as  many  turns  as  the  primary,  the  secondary 
current  will  be  of  only  VJ-0  the  voltage  of  the  primary.  A  very  important 
fact,  also,  is  that  the  amperage  of  the  secondary  current  undergoes  equal 
but  opposite  variations,  so  that  in  proportion  as  the  secondary  current 
increases  in  voltage  it  diminishes  in  amperage,  and  vice  versa.  The 
same  amount  of  energy  is  generated  in  the  form  of  a  high-tension 
current  of  low  amperage  or  of  a  low-tension  current  of  great  amperage. 
The  best  transformers  yield  a  secondary  current  whose  energy  is  equal 
to  97  per  cent,  of  the  energy  required  to  send  the  current  through  the 
primary  coil.  The  simplicity  of  the  apparatus,  two  insulated  coils 
with  an  iron  core,  which  requires  no  moving  parts,  and  the  fact  that 
it  can  be  constructed  to  transform  the  110  or  220  volts  alternating 
electric-light  current  into  a  low-tension  current  of  great  volume  for 
cautery  purposes,  or  a  high-tension  current  of  small  volume  for  .r-ray 
and  high-frequency  applications,  makes  the  transformer  exceedingly 


Fijr.  134.  — Caut 


valuable.     The   heating   effect   of   the   current   is   dependent   upon    its 
volume  or  amperage. 

Fig.  DM  shows  the  form  in  which  a  transformer  is  often  used  for 
cautery  purposes.  It  consists  of  two  separate  coils  of  insulated  wire, 
one  of  which  ills  inside  the  other,  bin  the  number  of  its  turns  traversed 
by  the  primarv  current  may  be  reduced  if  it  is  desired  to  reduce  the 
strength  of  the  secondary  current.  The  inner  coil  contains  an  iron 
core.  It  is  a  *t<  [)-<lmrn  tretiiufnrmrr,  since  it  gives  a  secondary  current 
of  lower  voltage  than  the  primary  current.  The  prnnarv  coil,  tin  "i1- 
fore.  has  a  large  and  the  secondary  a  small  number  of  turns.  Jts 


1(14  MI  '.MI  AI.   KI.K«  TKKTI  Y   AND  H(")\T(;KN   HAYS 

special  usefulness  for  the  cautery  lies  not  in  the  diminished  voltage1,  but 
in  the  increased  amperage.  A  platinum  wire  No.  2t>,  B.  tt  S.  gauge, 
will  become  incandescent  or  even  white  hot  from  the  passage  of  a 
current  of  1  volts  and  10  amperes,  and  make  an  excellent  cautery. 
The  same  energy  as  a  current  of  110  volts  and  0.4  ampere  would  not 
heat  t  he  wire  percept  ibly.  A  current  of  1 10  volts  and  10  amperes  would 
produce  the  >ame  healing  effect  upon  the  platinum  wire,  and  this 
could  be  obtained  from  the  electric-light  circuit,  but  there  are  two 
important  reasons  why  it  is  better  to  use  a  step-down  transformer: 
one  is  that  it  would  be  dangerous  to  take  a  current  as  strong  as  10 
amperes  from  one  of  the  110  volts  electric-light  sockets;  there  would 
have  to  be  -pedal  wiring  of  the  house  and  fused  knife-switches  at  the 
outlet  to  prevent  damage  from  lire,  just  as  in  the  case  of  the  heavy 
currents  used  for  the  .r-ray.  Y\  hen  we  remember  that  for  some  purposes, 
a  cauterv  current  of  !~)0  or  even  SO  amperes  is  used,  the  employment  of 
the  1  Ill-volts  current  is  seen  to  be  out  of  the  question.  The  trans- 
former enables  us  to  use  a  current  of  only  O.o  ampere  and  110  volts, 
and  convert  it  into  a  cautery  current  of  10  amperes  or  more.  It  is, 
therefore,  practicable  to  attach  it  to  anv  ordinary  alternating  current 
light  socket.  The  second  reason  why  the  transformer  is  regarded  as 
necessary  to  lit  the  alternating  electric-light  current  for  cautery  use  is 
the  danger  and  discomfort  to  operator  and  patient  from  handling  and 
applying  an  uninsulated  wire  charged  with  an  alternating  current  of 
1  Id  volts. 

The  Production  of  the  Secondary  Current  in  an  Alternating 
Current  Transformer. —  Kadi  time  the  primary  current  begins  to 
flow  in  a  direction  which  we  will  call  A,  a  current  is  induced  in  the 
secondary  coil  and  in  an  opposite  direction  to  that  in  the  primary. 
\Yhen  the  current  ceases  to  flow  in  the  direction  A  in  the  primary,  a 
current  in  the  same  direction  is  induced  in  the  secondary  coil.  These 
are  exactly  analogous  to  the  make  and  break  currents  in  an  induction 
coil.  In  the  case  of  the  alternating  current  there  is  another  element. 
At  the  instant  that  the  primary  current  ceases  in  the  direction  .1,  it  be- 
gins in  i  he  direct  ion  11 .  and  t  his  induces  a  make  current  in  the  secondary 
a  direction  contrary  to  It.  or,  in  other  words,  in  the  direction  .1. 
two  forces  tend  to  produce  currents  in  the  secondary 
<\  them  in  the  direction  .1.  The  two  forces  are  the 
•oinotive  forces  due  to  the  break  of  the  primary  current, 
i'  of  the  primary  current.  H.  The  result  is  the  induction 
'condary  current  in  the  direction  .1.  At  another  part 
1  make  ot  the  primary  current  .1  and  the  break  of  the 
/:  re  simultaneously  operative  in  producing  a  sec- 
i  the  direction  /<'.  The  alternating  currents,  .1  and  II. 
join  forces  in  the  production  of  an  alternating 
[he  secondary  current  may  be  of  the  same  char- 
,  current,  and  present  a  series  of  currents  of  full 
direction  and  then  in  the  other,  with  .-udi  a  sharp 
ie  t  v.  o  as  pract  ically  to  cause  a  break  in  the  cunvnt . 
-dl-ini luct  ion  m  the  primary  and  secondary  coils 
inductance  coil  introduced  m  the  primary  circuit' 
may  be  so  regulated  as  to  produce  a  current  analogous 
•urretit.  A  chart  ot  the  secondary  current  might 
'iitinuou-  curve  extending  alternately  above  and  below 


DYNAMIC    ELECTRICITY  105 

the  neutral  line,  and  undergoing  much  less  abrupt  transitions  than 
those  seen  in  a  chart  of  the  alternating  electric-light  current.  Such 
a  sinusoidal  current,  adjustable  at  from  5  to  30  volts,  is  of  value  in  thera- 
peutics, except  in  cases  where  a  unidirectional  current  is  required,  as 
for  diagnosis  or  for  electrolysis. 

This  type  of  step-down  transformer  has  greater  efficiency  than  if  the 
two  coils  were  straight  and  open  at  the  ends,  this  fact  being  due  to  the 
energy  wasted  at  the  two  open  ends  of  each  coil,  just  as  the  greatest 
efficiency  in  an  electromagnet  is  not  obtained  in  a  straight  bar.  The 
magnetic  flux  in  the  latter  case  is  carried  partly  by  the  iron  and  partly 
by  the  air.  through  which  it  effects  a  return  to  the  first  end  of  the  iron 
bar.  The  quantity  of  magnetic  flux  and  the  weight-bearing  attraction 
of  the  magnet  are  not  so  great  with  this  as  with  the  complete  ferric  type 
of  magnet,  of  which  the  horseshoe  magnet,  with  its  iron  armature,  forms 
the  most  familiar  example.  In  the  same  way  a  transformer  of  the 
straight  cylinder  type  wastes  a  certain  number  of  expanding  and  con- 
tracting lines  of  force  and  is  less  efficient  than  the  closed  magnetic  ring 
type  of  transformer.  The  straight  type  is  simple  in  construction,  and 
the  strength  of  the  current  may  be  readily  regulated  by  moving  one  of 
the  coils  out  of  or  further  into  the  other,  and  for  most  electrotherapeutic 
work  the  advantages  offset  the  fact  that  it  takes  a  little  more  primary 
current  than  some  other  types  to  yield  the  same  secondary  current. 

A  utep-up    transformer    may 

present  the  same  appearance  as  /^^—^^\  _  s 

a  step-down  transformer,  but  it 
has  a  greater  number  of  turns 
in  the  secondary  than  in  the 
primary  coil.  The  voltage  of 
the  secondary  current  is  pro- 
portionately greater,  and  may 
even  be  great  enough  to  excite  an 
x-ray  tube  or  a  high-frequency 
apparatus.  These  are,  in  fact, 

the  principal  purposes  for  which       Fi«-  i:r».— Diagram  of  a  step-up  transformer: 
,.  r         J_1  P.  Primary;  -S,  .secondary. 

a   step-up    transformer  tor   the 

alternating  electric-light  current  is  used  in  therapeutics.  In  both  of 
these  cases  the  maximum  efficiency  is  desired  and  a  closed  magnetic, 
ring  transformer  is  generally  used.  Fig.  13o  shows  in  a  diagrammatic 
way  the  construction  of  a  transformer  of  this  type.  It  consists  of  a 
complete  ring  of  soft  iron  and  two  coils  of  insulated  wire  passing  around 
the  iron  at  the  same  or  different  parts  of  its  periphery.  One  of  these  wires 
transmits  the  1 10  or  220  volts  alternating  electric-light  current,  and  is 
called  the  primary.  The  other  wire  has  alternating  currents  induced 
in  it  by  the  action  of  the  primary  current,  and  is  called  the  secondary. 
The  ends  of  the  latter  are  attached  to  the  poles  of  an  .r-ray  tube  or  to 
any  other  apparatus  through  which  it  is  desired  to  send  an  electric 
current.  The  voltage  of  the  secondary  current  bears  the  same  ratio 
to  that  of  the  primary  current  that  the  number  of  turns  in  the  secondary 
bears  to  the  number  of  turns  in  the  primary  coil.  This  type  of  trans- 
former may,  therefore,  be  used  as  a  step-up  or  a  step-down,  according 
to  whether  the  primary  current  is  connected  with  the  coil  having  tin1 
smaller  or  the  larger  number  of  turns.  In  either  case  the  efficiency  of 
such  a  transformer  is  very  great,  about  97  per  cent,  of  the  energy 


!()()  MKDICAl,    KLK(  TRICITY    AND    KO\T<;KN    RAYS 


required  to  produce  the  primary  current  reappearing  as  energy  in  the 
secondary  current.  The  energy  required  to  send  the  exciting  current 
through  the  primary  coil  consists  of  two  factors.  The  first  is  that 
which  is  required  to  overcome  the  ohmic  or  frictional  resistance  in  the 
primary  coil.  This  would  be  almost  the  total  energy  required  if  there 
were  only  a  primary  coil.  This  is  lost  as  electric  energy  and  reappears 
'he  second  is  the  energy  required  to  induce  the  current  in  the 
coil.  The  secondary  current  performs  work  in  whatever 
cautery,  or  .r-ray  tube,  for  example,  it  is  supplied  to,  and 
assuredly  required  to  produce  it.  An  illustration  from 
may  make  this  clear.  A  man  may  have  to  exert  only  a 
-mall  amount  of  energy  to  turn  a  crank  and  cause  a  cog-wheel  to  revolve 
if  onlv  frictional  resistance  is  to  be  overcome:  but  if  the  cog-wheel  is 
ley  by  which  a  heavy  weight  is  to  be  lifted,  the 
so  much  additional  energy  in  order  to  make  the 
coi^-wheel  revolve.  The  additional  resistance  to  the  revolution  of  the 
cog-wheel  winch  the  man  must  overcome  is  the  torce  exerted  by  the 
heavy  body  tending  to  cause  the  cog-wheel  to  revolve  in  just  the 
opposite  direction.  Returning  now  to  the  transformer,  the  secondary 
current  actually  does  exert  a  torce  tending  to  produce  a  current  in  the 
primary  coil,  which  would  be  in  the  opposite  direction  from  the  primary 
current.  This  opposing  force  to  be  overcome  in  the  primary  coil  is 
called  counterelect  roinotive  force. 

The  actual  ring  shape  i-  not  essential  to  the  closed  magnetic  ring 
transformer.  It  i-  often  better  to  have  it  made  up  of  many  separate 
narrow  iron  plate-  riveted  together  so  as  to  iorm  a  hollow  rectangle. 
Tin.-  is  very  easily  constructed  and  the  winding  of  the  two  coils  of  wire 
about  the  iron  core  is  greatly  simplified.  In  fact,  the  coils  are  wound 
separately  and  then  the  proper  section  of  the  core  slipped  inside  of  them 
before  being  riveted  to  the  other  sections.  In  sonic  cases  the  primary 
and  secondary  coils  are  wound  about  different  parts  of  the  circum- 
ference of  the  magnetic  ring,  and  in  other  cases  one  is  wound  directly 
over  the  other,  as  in  the  case  of  an  induction  coil.  The  same  precaution 
as  to  in -11  hit  imi  inu.-t  be  t  a  ken  as  wit  h  an  induct  ion  coil  of  equal  voltage. 
in  transformers  are  usually  immersed  in  oil.  which  has 
mvenient  and  highly  effective  insulating  medium. 
in  addition  to  the  insulated  wrapping  placed  around 
i  a  coil. 

-toriner  i.-  of  an  alternating  char- 
an  iin  luct  i<  ni  coil  in  being  equal  in 
ly  well  adapted  to  .r-ray  purposes, 

(pressed,    or 
1-    requires   special 

luct  |i  in   ci  ill.       Int  hi 

\\'e  a  ker     than     t  he 
cial     apparatus    has 
t  foill  >lesi  line,   very   - 
1   it .      Tims,  t  he  in!  n 
r-ray  coil  will   usua 
rehit  ive   \\  rakness   of   1  he 
which   will    pass   acn  iss   1  h 

all-     U  Illch     i.-    i  >I1  en     effect  JYi 
t  ioll    of    I  he    self-ill!  lllct  ji  ill 


DYNAMIC    HLKCTHICITY 


107 


coil  by  varying  the  number  of  turns  through  which  the  current  is  sent. 
Varying  the  different  connections  of  the  x-ray  tube  itself,  an  anticathode 
and  accessory  anode  and  vacuum  regulator  will  often  accomplish  the 
result.  These  various  measures  prove  ineffective  in  the  case  of  a  step-up 
transformer  for  the  reason  that  the  currents  are  similar  and  equal 
in  both  directions,  and  these  various  procedures  would  have  about 
as  much  effect  upon  the  currents  flowing  in  the  desired  direction  as 
upon  those  in  the  opposite  direction.  The  alternating  current  trans- 
former without  any  modification  has  been  used  to  actuate1  an  x-ray 
tube,  and  was  thought  fairly  satisfactory  until  the  induction  coil  was 
brought  to  its  present  state  of  efficiency.  The  recent  work  of  d'Arsonval 
and  (laiffe  has  resulted  in  the  application  of  devices  for  suppressing  one 
set  of  impulses  from  the  transformer.  Snook  and  others  rectify  the 
secondary  current.  These  two  devices  result  in  the  production  of  a  cur- 
rent so  uniform,  efficient,  and  so  easily  regulated  that  the  modified  trans- 
former is  probably  the  best  .r-ray  apparatus  in  existence.  It  requires 
no  interrupter.  It  works  upon  the  alternating  electric-light  current, 
and  has  such  advantages  over  the  induction  coil  as  to  render  it  desirable 
even  where  the  supply  current  is  of  the  direct  type.  In  the  latter 
case  a  motor  generator  or  a  rotary  transformer  operated  by  the  direct 
current  is  employed  to  produce  the  alternating  current  for  the  trans- 
former. This  adds  somewhat  to  the  cost,  but  very  little  to  the  care  of 
the  apparatus.  The  most  essential  points  in  the  suppression  of  one 
set  of  impulses  is  the  presence  of  two  ventril  or  valve-tubes  connected 
in  series  and  forming  a  shunt  circuit  between  the  two  poles  of  the  coil. 
Each  ventril  tube  is  a  vacuum  tube  with  electrodes  of  two  different 
characters,  one  of  which  will  readily  act  as  a  cathode  and  the  other  will 
not  ordinarily  do  so.  Secondary  currents  can  pass  through  such  a 


Fig.  l.'iG. —  Parallel  arrangement  of  ventril  tubes. 

ventril  tube  without  hindrance'  in  a  certain  direction,  but  with  the 
greatest  difficulty  in  the  opposite  direction.  Introducing  one  or.  as 
in  (laif'fe's  apparatus,  two  ventril  tubes  between  the  poles  of  a  trail— 
former  has  the  effect  of  affording  a  short  and  direct  path  for  the  sec- 
ondary currents  in  one  direction  while  having  no  effect  upon  those  in 
the  other  direction.  The  two  poles  of  the  transformer,  therefore, 
transmit  to  the  .r-ray  tube  a  uniformly  interrupted  series  of  secondary 
currents  which  are  all  in  one  direction.  Figure  liW  shows  the  gener;d 
arrangement  of  these  ventril  tubes;  />  and  //  are  the  two  poles  of  the 
transformer  and  the  two  ventril  tubes  are  arranged  so  that  the  current.- 


ItiS 


MEDK-AL    ELEITKK'ITY    AND    K(")XTc;ENT    RAYS 


enter  the  corresponding  end  of  each  tube,  the  positive  end  of  one  tube 
U.in.r  connected  to  tin-  negative  end  of  the  other  by  a  conducting  wire; 
//  which  is  marked  +.  is  the  pole  which  is  to  be  connected  with  the 
•mode  or  positive  terminal  of  the  .r-ray  tube;  and  •/>,  which  is  marked 
i*  to  be  connected  with  the  cathode  of  the  .r-ray  tube.  Negative 
impulses  from  //  pass  readily  through  the  ventril  tubes  whose  cathodes 
are  both  nearest  //.  but  negative  impulses  from  />  find  a  tremendous 
resistance  to  their  passaire  through  the  two  valve-tubes,  .lust  a  word 
as  to  the  construction  of  a  ventril  tube  may  not  be  out  of  place.  It 


IMLT.  1H7.  —  Scries  arrangement  of  ventril  tubes. 


ut 


i-  a  tube  of  about  the  same  degree  of  vacuum  as  an  .r-ray  tube,  and 
.-tiould  l»c  provided  with  a  means  of  regulating  the  vacuum.  The 
type  shown  in  the  illustration  has  two  leading-in  wires,  one  of  which 
terminate-  in  a  small  aluminum  electrode,  and  the  other  in  a  long  spiral 
of  aluminum  presenting  many  times  the  surface  area  of  the  first.  The 
high-tension  current  used  for  /-ray  work  encounters  very  little  resist- 
ance when  pas.-iim  in  Mich  a  direction  that  the  cathode  is  the  electrode 
with  very  large  area,  but  is  arrested  when  the  polarity  is  reversed. 
negative  current  will  pass  from  the  long  spiral  electrode  to  the 
it  will  not  pass  in  the  opposite  direction.  A  different. 
been  made  of  a  ventril  tube,  placing  it  in  series  with 
so  that  it  will  allow  the  current  to  pass  through  it  to 
in  the  proper  direction,  but  will  act  as  an  insuperable 
in  the  opposite  direction.  The  ventril  tube  is 
permit  the  passage  of  the  direct  discharge  from 
ugh  the  /-I'ay  tube  and  to  obstruct  the  inverse 
e  current  which  the  ventril  tube  transmits 
the  ventril  lubes  are  used  to  shunt  or 
will  readily  transmit,  and  to  leave 
ass  immediately  from  the  poles  of  the 
This  i-  probably  t  he  best  arrangement. 
on  p.  "s'.i.  The  Henifar  self-rectifying 
he  inverse  discharge  from  an  induction 
ci  ified  siep-up  transformer  with 
the  possible  addition  of  a  series 
th 


DYNAMIC    ELECTRICITY  169 

former  in  one  direction  sufficiently  we  may  have  an  x-ray  generator 
without  moving  parts  and  much  simpler  and  cheaper. 

The  Coolielge  x-ray  tube  is  self -rectifying  to  a  great  extent.  A 
question  naturally  arises  as  to  the  much  fewer  cycles  of  this  secondary 
current,  but  it  is  probable  that  the  same  voltage  and  milliamperage  will 
produce  approximately  the  same  effect  as  with  the  present  more  fre- 
quent cycles.  Gaiffe's  apparatus  for  the  employment  of  an  alternating 
current  transformer  for  x-ray  work  includes  liquid  volt  controllers, 
condensers,  and  other  appliances  which  will  be  described  on  another 
page.  The  whole  combination  is  a  practicable  thing,  whereas  a  simple 
transformer  is  not  perfectly  adapted  to  the  purpose.  Snook's  and 
similar  transformers  with  a  rectified  high-tension  discharge  are  further 
discussed  on  p.  746. 

DETECTION  AND  MEASUREMENT  OF  ELECTRIC  CURRENTS 

General  Considerations. — Sources  of  electricity  are  really  means 
by  which  an  electromotive  force  is  produced,  or  a  difference  in  potential  is 
created  between  two  points.  This  is  known  also  as  the  tension  of  the 
current  and  is  expressed  in  volts.  It  produces  a  flow  of  electricity 
through  any  conductor  uniting  the  two  points.  The  current  has  a 
tendency  to  establish  a  neutral  condition  by  equalizing  the  electric 
state  of  the  two  points,  and  is  analogous  to  the  flow  of  water  from  a 
higher  to  a  lower  level.  The  amount  of  electricity  transferred  in  a 
second  is  the  strength  of  the  current,  is  called  its  intensity,  and  is 
expressed  in  amperes.  The  rate  of  flow  or  the  intensity  of  the  current  is 
determined  by  two  factors — the  tension  of  the  current  and  the  resistance 
of  the  conductor.  It  is  directly  proportional  to  the  tension  or  voltage, 
so  that  if  the  voltage  is  twice  as  great,  twice  as  many  amperes  of  current 
will  flow  through  the  same  resistance.  It  is  inversely  proportional  to 
the  resistance,  so  that  if  the  resistance  is  twice  as  great,  the  same 
number  of  volts  will  cause  only  half  the  number  of  amperes  to  flow. 
All  substances  will  transmit  electricity,  but  some,  including  most  metals 
and  many  liquids,  do  so  with  so  little  resistance  that  they  are  called 
conductors,  and  are  used  for  the  purpose  of  transmitting  electricity. 
Other  substances  are  poor  conductors.  Still  others  are  such  poor 
conductors  of  electricity  that  they  are  called  non-conductors,  and  are 
used  as  a  means  of  insulating  bodies  which  are  charged  with  electricity 
or  which  are  conducting  an  electric  current. 

In  the  case  of  a  very  good  conductor,  like  copper  wire,  there  is, 
nevertheless,  a  certain  amount  of  resistance,  and  a  certain  proportion  of 
the  current  seeking  to  pass  through  it  is  changed  into  heat  by  an  effect 
analogous  to  that  of  mechanic  friction.  The  ohm  as  an  absolute  stand- 
ard of  electric  resistance  is  the  resistance1  at  a  temperature  of  32°  F. 
of  a  column  of  mercury  one  square1  millimeter  in  cross-section  and  100.3 
cm.  long.  The  coulomb  as  an  absolute1  standard  of  elect rie1  quantity 
is  the1  quantity  which  when  passe'd  through  a  solution  of  nitrate1  of  silve>r 
will  cause1  1.1  IS  milligrams  of  metallic  silver  to  be1  depe>sited.  The 
ampeMv  as  an  absolute1  unit  of  cunvnt  flow  e>r  intensity  is  a  eurrent  e>f  one 
coulomb  per  seronel.  The1  volt  is  not  an  absolute1  but  a  composite 
unit  e>f  potential  e>r  tension;  it  is  an  e'le'ctromotive'  fore-e  whie'h  will  e-ause- 
a  e'urrent  e)f  erne1  ampere1  to  flenv  through  a  resistance  of  one1  ohm.  A 
Daniell  cell  produce's  an  electromotive  force  of  about  1.08  volts. 


17H  Mi;i>I<  AI.    KLK<  TKKITY    AM)    RONTGEN    RAYS 

Ohm'--  Inn-  is  of  fundamental   importance: 

(  ';   :         iff  [•]  CK:         or  H  *,'  . 

It  means  that  the  intensity  <>f  the  current  in  amperes  is  equal  to  the 
electromotive  toive  in  volts,  divided  by  the  resistance  in  ohms.  One 
or  uvo  examples  may  l>e  given. 

If  the  electromotive  force  is  110  volts  and  the  resistance  10  ohms, 
tin-  current  .-tivng'th  \vill  be   1  1   amperes: 

"  amPeres- 

I:'  the  resistance  is   1   ohm  and  the  intensity  or  strength  of  current 
flow  is  10  amperes,  the  potential  or  tension  is  10  yohs: 

i:  <'!!:       I!      -     10     X     1     =     T)  volts. 


K  R    =  40tj.()(J(i  ohms. 

0.01 .) 

Values  oi  I!.  I-!,  and  (',  about  like  those  in  the  last  example,  are 
found  in  the  application  of  the  voltaic  current  to  the  human  body. 
'1  In  values  in  t  he  tir.-t  example.  110  volts,  etc..  are  like  those  sometimes 
f"und  in  ./'-ray  work:  and  those  in  the  second  example.  10  volts.  10 
ai  >  res,  and  1  ohm.  are  like  those  occurring  in  the  use  of  the  galvuno- 
caUt  'TV. 

These  relations  an-  universally  true,  although  either  K  or  R  may  be 
a  composite  instead  of  a  simple  quantity.  The  measurement  of  electric 
quant  it  ies.  st  rength  of  current,  potential,  or  resistance  almost  invariably 
d-  I"  nd-  upon  the  application  of  this  law;  and  the  construction  of  all 
'  •  -t  ric  :  pparatus  is  guid'-d  bv  it . 

Th«-  voltameter   i-  an    instrument   by   which   the  quantity  of  elec- 
tricity which  ha-  (lowed  in  a  given  time  i-  measured  by  the  increase  in 
ol    a    -ilver    plate    from    tin-   deposit    (,f   metallic  silver  upon  it. 
in-'rument  is  really  a  measurer  of  coulombs,  because  the  quantity 
•  r  deposited     1.1  Is  milligrams)  is  t  he  same  for  the  same  number  of 
coulomb-  whet  her  i  he  current  is  at  t  lie  rate  of  ]  coulomb  per  second  or  1 
coulomb  p<-r  minut'-:  that  i-.   1  ampere,  or  (.'(|  ampere. 

''tie  coulomb  liberate,;   \-_>  ,..,..  ,  ,f  hydrogen  gas.      A  water  voltameter 

d  in  cubic  centimeters,  or  directly  in  coulombs. 
The     Centimeter-gram-second     System    of    Electric    Units.-   The 
tii'-'fi    i-    the   np-fric   unit    of   length,   and   i-   equal   to  0.:->7o(.l   inch. 
•    jilt    in   the  -ame  -y-tem.  and  i-  the  weight 

'          •         ri  til  iin  iter  at    1     <  '.,  the  temperature  at  which  water 

'\'\. <••<'••'•'  \-   '  he  unit   of  t  hue  in  t  he  same 
•  -  m. 

luce-  mot  ion  or  change  of  mot  ion  in  a  body. 
'   ' '!   torci  .  and  acting  for  one  -econd  upon 


DYNAMIC     KLKCTKHTn  171 

a  body  weighing  one  grain,  it  will  give  the  body  a  velocity  of  one  centi- 
meter per  second.  \\'ork  is  the  product  of  a  force  by  the  distance 
through  which  it  acts.  The  ('.  (i.  S.  unit  of  work  is  the  crtj.  or  the 
work  done  in  overcoming  a  force  of  one  dyne  through  a  distance  of  one 
centimeter.  A  concrete  example  of  work  is  the  raising  of  a  bodv 
weighing  one  gram  to  a  height  of  one  centimeter.  Since  the  attraction 
of  gravity  acting  on  a  mass  of  one  gram  for  one  second  will  give  a 
velocity  of  (,)S1  centimeters  per  second,  the  force  exerted  by  gravity 
upon  a  body  weighing  one  gram  is  (.)S1  dynes.  Therefore,  the  work 
done  in  raising  a  mass  of  one  gram  to  a  height  of  one  centimeter  is 
OS!  ergs.  Other  units  of  work  are  the  kilogram-meter  =100,000X981 
ergs,  and  the  foot-pound  —  1 .856  X  H)7  ergs--  13.56  million  ergs. 

Kindle  rncn/i/  is  the  work  which  a  body  can  do  by  virtue  of  its 
motion.  Potential  ener(/t/  is  the  work  which  a  body  can  do  by  virtue  of 
its  position.  The  unit  in  either  case  is  the  erg. 

The  unit  of  the  rate  of  work  is  one  erg  per  second.  A  horse-power 
=  33,000  foot-pounds  per  minute  is  7460  million  ergs  per  second.  The 
horse-power  represented  by  an  electric  current  is  equivalent  to  the 

,    IT         '  ( <2R  !v'  .  .  . 

electric  energv  or  -„  ._     or  -_,.,-  or  -_  ..  — ,  in  which  expression    h  = 
/46  /46  746R 

volts,  ('  =  amperes,  and  R  =  ohms. 

One  horse-power  is  f  kilowatt  or  740  watts.  One  kilowatt  is  1.34 
horse-power. 

Electric  units  are  derived  from  the  centimeter-gram-second  system. 
There  are  two  sets  of  them — the  electrostatic  and  the  electromagnetic 
systems.  The  electrostatic  system  has  for  its  unit  of  quantity  the 
amount  of  electricity  which  will  exert  a  force  of  one  dyne  upon  a  similar 
quantity  of  electricity  at  a  distance  of  one  centimeter.  The  force  will 
be  one  of  attraction  if  one  charge1  is  positive  and  the  other  negative; 
and  of  repulsion  if  both  are  of  the  same  sign  (4-  or  — ).  The  electro- 
static units  of  current,  electromotive  force,  and  capacity  are  derived 
from  this  unit  of  quantity. 

The  electromagnetic  system  of  ('.  (1.  S.  units  is  the  one  that  is 
commonly  in  use,  and  is  based  upon  the  force  exerted  between  two 
magnetic  poles.  For  instance,  a  icnit  tnni/ni'tie  pole  repels  a  similar  pole 
at  a  distance  of  one  centimeter  with  a  force  of  one  dyne.  The  C'.  (i.  S. 
unit  of  current  is  a  current  which,  passing  through  a  wire  one  centimeter 
long,  bent  into  an  arc  of  a  circle  whose  radius  is  one  centimeter,  will 
exert  a  force  of  one  dyne  upon  a  unit  magnetic  pole  situated  at  the 
center  of  the  circle.  The  C.  G.  S.  unit  of  (jiiantiti/  is  the  amount  of 
electricity  transferred  in  a  second  by  a  current  of  a  strength  of  one  unit. 
The  ('.  (1.  S.  unit  of  electrotnotire  force  is  that  which  must  be  maintained 
between  the  ends  of  a  conductor  in  order  that  a  current  of  unit  strength 
shall  do  one  (\  (i.  S.  unit  of  work  in  a  second.  The  C.  (i.  S.  unit  of 
rexfxfttnci'  is  that  of  a  conductor  in  which  a  unit  of  current  is  produced 
by  a  unit  of  electromotive  force.  The  C.  (i.  S.  unit  of  capacity  is  t In- 
capacity of  a  condenser  which  will  be  at  a  potential  of  one  unit  ot 
electromotive  force  when  charged  with  one  unit  of  quantity. 

Practical  Units  of  Electricity.  The  electric  units  in  every-day 
use  are  arbitrarily  selected,  and  are  of  a  size  to  be  readily  measured, 
so  that  the  currents  ordinarily  employed  can  be  represented  by 
onlv  a  few  units.  The  comparison  between  the  ohm.  for  instance,  and 
the  C.  <  i.  S.  unit  of  resistance  is  about  like  that  between  the  ton  ami  t  he 
grain  as  units  of  weight. 


172  MEDICAL    ELKCTHICITY    AND    RONTGEN    RAYS 

The  conlnnih  \<  /,,  ('.  (i.  S.  unit  of  electric  quantity,  or  10 — l  C.  G.  8. 
units.  It  decomposes  O.OOOO'.tl")  gram  of  water  or  deposits  1.1  IS 
milligram  of  silver.  It  is  the  amount  of  electricity  transferred  in  a 
second  by  a  current  of  one  ampere. 

The  nn<i>tr<  is  the  unit  of  current  or  of  the  rate  of  flow  of  electricity. 
A  current  of  one  ampere  transfers  one  coulomb  of  electricity  pel1  second. 
It  decomposes  0.0000(.)l~>  gram  of  water  per  second.  It  is  equal  to 
j1,,  ( '.  ( I.  S.  unit  of  current . 

The  militant f»  n   is  one-thousandth  of  an  ampere. 

The  rult  is  the  practical  unit  of  electromotive  force,  and  is  the 
electromotive  force  which  will  maintain  a  current  of  one  ampere  through 
a  resistance  of  one  ohm.  It  is  equal  to  H)8  C.  G.  S.  units  of  electro- 
motive force,  and  is  about  7  per  cent,  less  than  the  electromotive 
force  of  a  Daniell  cell. 

The  uhtti  is  the  practical  unit  of  resistance,  and  is  equal  to  H)9  C.  G.  S. 
units  of  resistance.  It  has  been  defined  by  international  agreement 
as  the  resistance  of  a  column  of  mercury  106  centimeters  long,  one 
square  millimeter  in  cross-section,  and  at  a  temperature  of  0°  C.  or  32°  F. 
No.  10  copper  wire  is  101.0  thousandths  of  an  inch  in  diameter.  A 
piece  1000  feet  long  has  almost  exactly  1  ohm  resistance. 

T\\c ftir<i<l  is  the  practical  unit  of  capacity,  and  is  equal  to  10"  C.  G.  S. 
units  of  capacity.  It  is  such  a  capacity  that  a  coulomb  will  charge 
it  to  a  potent  ial  of  one  volt . 

The  tri/rrtifnrinl  is  one-millionth  of  a  farad.     A  Leyden  jar  with  a 
total  coated  surface  of  one  square  yard  would  have  a  capacity  of  about 
'„  microfarad. 

The  u'<itt  is  the  practical  unit  of  electric  power,  and  i.-  equal  u 
10  C.  G.  S.  units  of  power.  It  is  the  power  conveyed  by  a  current  of 
'lie  ampere  through  a  conductor  whose  resistance  is  one  ohm,  and 
which  consequently  requires  an  electromotive  force  of  one  volt.  It  is 
equal  to  one  joule  per  second,  or  T](i  horse-power.  The  number  of 
watts  i>  equal  to  the  number  of  amperes  multiplied  by  the  number  of 
vnlts  \\  ('!•  Or.  it  i.-  equal  to  the  square  of  the  current  strength 
iii  amperes  multiplied  by  the  resistance  in  ohms — W  =  ('-H.  Or  it  is 

electromotive  force  in  volts  divided  bv  the 


may.  for  example,  indicate  a  cur- 
s,  or  a  current   of  o  amperes  at   a 
units  ot  elect  ric  ]>ower. 
watts  acting  during  one  hour,  is  a 
i-  th<'  unit  upon  which  the  electric- 
'  he  use  of  t  he  current .      It   may. 
in    an    hour  by   a    current    of    10 
er   t  han    i  me    kilowat  t    act  inn 
-mailer  current    for  a   longer 


or   work    upon    which   tin 


DYNAMIC    ELECTRIC 'ITY 


173 


C.  G.  S.  units  of  work.  It  is  found  to  he  the  amount  of  heal  necessary 
to  raise  0.2405  gram  of  water  one  degree  Centigrade. 

The  caloric  is  the  French  unit  of  heat,  and  is  the  amount  of  heal 
required  to  raise  the  temperature  of  1  gram  of  water  1°  C.  It  is  analo- 
gous to,  but  much  smaller  than,  the  Knglish  heat  unit,  the  pound-degree. 
For  the  amount  of  heat  generated  by  an  electric  current  see  page  202. 

Dynamic  electricity  produces  measurable  physiologic,  chcmic,  me- 
chanic, and  physical  effects.  Under  the  latter  head  would  be  included 
thermal,  luminous,  and  magnetic  effects.  The  magnetic  effects  are  es- 
pecially available  for  ascertaining  the  presence  and  strength  of  electric 
currents,  and  will  be  the  first  to  be  described. 

ELECTROMAGNETIC    GALVANOMETERS 

Oersted's  initial  discovery  in  regard  to  the  intrinsic  relation  be- 
tween electricity  and  magnetism  consisted  in  the  observation  that  if  a 
current  of  electricity  passes  through  a  wire  passing  above  or  below  a 


.  —  Principle  of  the  needle  galvanometer. 


magnetic  needle  like  a  compass,  the  needle  tends  to  place  itself  at  a 
right  angle  to  the  wire.  As  to  direction,  if  the  current  is  above  the 
needle  and  is  passing  from  south  to  north,  the  north  pole  of  the  needle 
will  be  deflected  toward  the  west;  if  the  current  is  from  south  to  north 
and  is  below  the  needle,  the  latter  is  deflected  toward  the  east;  just 
the  opposite  deflections  occur  if  the  current  is  flowing  from  north  to 
south  (Fig.  138). 

Figure  139  represents  the  case1  of  a  galvanometer  with  a  single  needle 
a-b,   and  a   current   flowing  through  a   single   complete   turn  of  wire. 


The  current  passes  from  south  to  north,  above  the  needle  and  returns 
from  north  to  south  below  the  needle.  Hoth  pails  of  the  loop,  there- 
fore, carry  a  current  which  tends  to  make  the  needle  swerve  to  the  west. 
The  angular  distance  through  which  the  needle  moves  depends  princi- 
pally upon  the  strength  of  its  magnetism  (which  tends  to  keep  it  in  a 
north  and  south  direction)  and  upon  the  strength  of  the  current.  I'sing 
the  same  needle  for  different  observations,  the  apparatus  will  serve  a> 
a  measure  of  the  strength  of  the  cunvnt.  The  strength  of  the  effect 


174 


MKDICAL    ELECTRICITY    AND    KONTCKX    RAYS 


upon  the  needle  is  multiplied  by  using  a  coil  of  many  turns  of  wire 
instead  of  a  >ingle  loop:  and  the  sensitiveness  of  the  needle  is  increased 
by  making  it  a-tatic.  Thus,  Fig.  1  H)  consists  of  using  two  magnetic 
needles  fastened  to  the  same  vertical  axis,  one  with  its  north  pole 
pointing  in  the  usual  direction,  but  the  other  with  its  poles  reversed. 
Both  are  suspended  by  a  silk  thread  and  the  coils  of  wire  pass  around 
only  the  lower  needle.  The  effect  is  the  same  as  it  would  be  upon  a 
needle  of  the  si/e  of  both  combined,  and  with  the  magnetism  of  both 
combined,  but  opposed  by  the  influence  of  the  earth's  magnetism  only 
to  the  extent  represented  by  the  difference  between  the  strength  of 
the  two  needle<.  These  must  not  be  exactly  equal.  If  they  were 
there  would  be  no  force  opposed  to  the  directive  influence  of  the  electric 
current,  and  weak  as  well  as  strong  currents  would  cause  the  needle 
to  assume  a  position  at  right  angles  to  the  plane  of  the  wire.  This 
would  destroy  its  value  as  a  means  of  measuring  the  strength  of  different 
currents. 

Tin'  strength  of  the  current  is  indicated  by  the  extent  of  the  angle  of 
deflection.  It  is  difficult  to  calculate  this  from  purely  theoretic  data,  and 
these  instruments  are  usually  graduated  by  comparison  with  standard 
mst  rument>. 

The  resistance  of  a  galvanometer  without  its  shunt  is  usually  from 
100  to  (100  ohms. 

The  d'Arsonval  milliamperemeter  and  several  other  types  of  electro- 
magnetic galvanometer  in  common  use  are  described  on  pages  189-193. 

Hot  Wire  Galvanometer. — This  depends  upon  the  heating  effect 
ot  an  electric  current  upon  a  fine  wire  through  which  it  passes  with 
considerable  ohmic  resistance.  The  hot  wire  expands  and  allows 
the  pointer  to  move  across  the  dial  under  the  influence  of  a  spring. 
It  is  applicable  to  alternating  and  high-frequency  currents,  as  well  as 
direct  currents,  and  to  almost  any  voltage.  It  is  difficult  to  secure 
great  accuracy  with  an  instrument  of  this  type.  It  does  not  indicate 
t  he  direct  ion  of  t  he  current . 

The  Capillary  Electrometer.- --This  is  an  instrument  which  is 
useful  in  measuring  the  electromotive  force  or  potential  differences 


urrents    in    animals    01 


r    pat  h< il< >iric    elect  ric   curn 


I'   i-  very  sen-hive,  thouu-h  not  so  sensitive  as  a  galvanometer 


1(1  made.      It   ha-  the  advantage  of  giving  accurate  measurements 


DYNAMIC    ELECTRICITY  175 

of  the  electromotive  force,  even  of  a  voltaic  couple  of  extremely  great 
internal  resistance.  This  is  the  condition  in  physiologic  and  pathologic 
currents,  and  is  not  so  perfectly  met  by  a  galvanometer.  The  capillary 
electrometer  acts  under  these  conditions  of  small  electromotive  force 
and  very  great  internal  resistance  practically  in  an  electrostatic 
manner. 

Lipmann's  capillary  electrometer  (Fig.  141)  is  based  upon  the  influ- 
ence of  electricity  upon  surface  tension  and  capillary  attraction.  A 
glass  tube,  the  lower  part  of  which  is  of  capillary  caliber  and  dips  into 
a  jar  of  dilute  acid,  is  open  top  and  bottom  and  has  its  upper  part 
tilled  with  mercury.  Under  these  circumstances  the  mercury  does 
not  run  out  of  the  tube,  but  rests  at  a  certain  level  upon  the  surface  of 
the  dilute  acid  in  the  capillary  portion  of  the  tube.  As  usually  con- 
structed, this  level  is  above  the  general  level  of  the  solution  in  the  jar. 
The  level  may  be  adjusted  by  changing  the  pressure  of  the  column  of 
mercury.  Observations  of  the  level  are  made  with  a  microscope  or  an 
image  of  the  capillary  electrometer  may  be,  thrown  upon  a  revolving 
cylinder  of  photographic  paper  and  produce  a  record  of  the  variations. 
Connecting  the  mercury  in  the  upper  part  of  the  tube  with  the  negative 
wire  and  the  mercury  in  the  bottom  of  the  large  jar  with  the  positive 
wire,  the  level  of  the  surface  at  which  the  mercury  and  the  acid  solution 
meet  in  the  capillary  tube  rises  the  moment  the  current  is  turned  on. 
The  difference  in  potential  between  the  two  masses  of  mercury  is  pro- 
portional to  the  height  to  which  the  level  rises  or  also  to  the  mercurial 
pressure  required  to  maintain  the  original  level.  This  form  of  electrom- 
eter is  extremely  sensitive,  responding  to  even  the  weak  currents 
characteristic  of  animal  electricity,  and  is  instantaneous  in  its  response 
to  such  currents  and  in  its  return  to  the  zero  mark  after  the  current 
ceases.  It  is  used  in  many  physiologic  experiments,  such  as  the  measure- 
ment of  muscular  currents. 

The  Siring  Electrometer. — Einthoven  s  string  electrometer  is  based 
upon  the  fact  that  when  a  current  of  electricity  passes  through  a  wire 
tightly  stretched  in  a  powerful  magnetic  field  the  wire  is  deflected  toward 
one  of  the  poles  of  the  magnet.  A  powerful  light  and  a  high-powered 
photomicrographic  apparatus  are  used  to  throw  an  image  magnified 
250  times  or  more  upon  a  moving  strip  of  bromide  of  silver  photographic 
paper  through  a  slit  which  is  at  right  angles  with  the  length  of  the  wire. 
The  string  or  wire  originally  used  by  Einthoven  consisted  of  a  filament  of 
quartz  obtained  by  directing  the  flame  of  a  blow-pipe  upon  a  piece  of 
quartz  fastened  at  one  end  and  having  a  heavy  weight  suspended  from 
the  other.  The  silvered  quartz  thread  was  one-third  the  diameter  of  a 
red  blood-cell.  The  electric  resistance  was  about  10,000  ohms.  The 
apparatus  improved  by  Xicolai  and  Huth  (page  324"  employs  a  platinum 
wire  about  4  inches  long  and  having  a  resistance  of  0000  ohms.  In 
either  case  the  electromagnet  must  be  a  powerful  one  and  in  Nicolai's 
apparatus  weighs  GO  pounds.  It  must  be  actuated  by  a  direct  current, 
either  from  the  electric-light  circuit  or  from  a  storage  battery. 

Correction  for  Internal  Resistance  in  Measuring  the  Electro- 
motive Force  of  a  Voltaic  or  a  Storage-cell  during  Discharge.— 
It  is  not  sufficient  to  determine  the  difference  in  potential  between  the 
two  poles  of  the  batiery  by  means  of  a  voltmeter  or  a  potentiometer. 
The  number  of  volts  found  in  this  way  while  a  current  is  passing  through 
the  batterv  must  be  corrected  bv  taking  into  account  the  fact  that  the 


17()  MKDK'AL    KLKCTKICITY    AND    KONTCJKN    HAYS 

resistance  of  the  electrolyte  in  the  battery  cell  through  which  a  current 
is  passing  will  in  itself  require  a  difference  in  potential  equal  to  the 
current  multiplied  by  the  internal  resistance.  This  amount  in  volts 
i>  to  be  added  to  the  measured  difference  in  potential  between  the  two 
poles  to  find  the  total  electromotive  force  of  the  cell. 

Another  condition  remains  to  be  considered.  In  the  case  of  a 
battery  with  a  certain  number  of  volts  difference  in  potential  between 
its  poles  the  current  passing  through  the  external  circuit  is  equal  to  the 
voltage  at  the  two  poles,  divided  by  the  resistance  in  the  external 
circuit.  Rut  doubling  the  external  resistance  does  not  cause  the  current 
to  lie  just  half  a-  great.  In  order  to  reduce  the  current  one-half,  the 
total  resistance,  internal  as  well  as  external,  must  be  doubled.  The 
difference  in  potential  at  the  two  poles  will  be  found  to  have  undergone 
a  change  if  only  the  external  resistance  is  varied,  and  the  new  strength 
of  current  cannot,  therefore,  be  calculated  from  the  old  voltage  at  the 
two  poles.  The  new  voltage  may  be  measured  by  a  voltmeter  or  a 
potentiometer,  and  then  this  may  be  divided  by  the  new  resistance  of 
the  external  circuit  to  obtain  the  number  of  amperes  of  current. 

The  total  electromotive  force  divided  by  the  total  resistance  always 
gives  the  strength  of  the  current;  and  whatever  the  intermediate 
voltages  or  resistances  may  be.  their  effect  is  determined  only  by 
combination  with  the  conditions  in  the  remainder  of  the  circuit. 

The  current  from  a  single  storage-cell  with  an  external  resistance 
of  ,,•,',,,•  ohm  maybe  10  amperes.  And  this  would  indicate  two  different 
things.  One  is  that  under  the  conditions  described  the  potential 
difference  between  the  poles  of  the  battery  is  only  TJ-jj  volt  (Y  =  ('R  or 
,/,,-,  volt-  10  amperes  x  TTnro-  otim,  according  to  Ohm's  law).  This  is 
true  in  .-pile  of  the  fact  that  on  open  circuit  or  with  a  large  external 
resistance  the  potential  difference  between  the  two  poles  of  the  cell 
will  be  _>  volts  or  over.  The  other  fact,  which  is  indicated  when  the 
current  produced  by  a  known  electromotive  force  of  about  2',  volts 
an  external  resistance  of  only  yj,1,,,,  ohm  is  only  10  amperes,  is  that 
•unvnt  Mrength  must  in  this  case  be  almost  entirely  determined  by 
internal  resistance  of  the  storage-cell.  If  it  depended  only  on  the 
resistance,  an  electromotive  force  of  21,  volts  would 
nt  of  2")00  amperes.  This  will  be  found  to  be  of  impor- 
ect  ric  currents  produced  by  physiologic  processes, 
tential  between  two  portions  of  the  body  may  be 
se  are  joined  by  a  conductor  of  1  ohm  resistance, 

11  OS   volt 

-    0.0X0   ampere,  or   SO  milhamperes, 
1  ohm 

Vt'i'v   much    weaker    one.      The    resistance  of  the  body  may  bo 
HIS    or    more,    and    this    must    be    added    to  the  external  resist- 
cal'-iihiting    the    -trength    of    the   current.       The   total    elect  ro- 
t"t'ce  may  in  this  way  be  approximately  the  0. OX  volt  difference 

;  i1  •!:    i1  }','<"  1  it  . 

/   >lif  I'd/I  1/1  in/  (it  n  Si/n/li    i'Jt  rtrotlc. — This  finds 
•ation    in    the  case  of  *t<itic  <  l<  ctrtcitij,  where  the 
it    the    divergence    of    a    gold-leaf    electroscope 
•asurement . 

•a ted    by   physiologic    processes   is  so   small   that 
inMrumonts   are    required    to   measure   it.      The 


DYNAMIC    ELECTRICITY 


177 


most  practicable  plan  is  to  lend  an  insulated  wire  from  the  single  source 
of  potential  which  it  is  desired  to  measure  and  have  this  wire  terminate 
in  an  electrode  which  is  non-polarizable  in  a  certain  electrolyte.  A 
standard  electrode  whose  potential  is  known  is  placed  in  another 
part  of  the  same  electrolyte1.  The  difference  between  the  potentials 
of  the  two  electrode's  is  found  by  means  of  the  potentiometer,  and  from 
this  the  unknown  potential  is  readily  calculated. 

Figure  142  shows  a  practicable  arrangement  of  the  two  electrodes, 
the  calomel  electrode  being  used  as  a  standard.  This  electrode;  con- 
sists of  mercury  covered  by  a  layer  of  calomel,  and  the  wire  elipping  into 
it  is  insulated  from  contact  with  the1  electrolyte  (normal  K('l  solution) 
by  a  glass  tube-.  Inverted  U-shaped  tubes  from  this  jar  and  from  the  jar 
containing  the  other  electrode  dip  into  the1  same  solution  in  a  middle 
jar.  These  inverted  U-shaped  tubes  are  filled  with  the  same  solution 
by  blowing  through  tin1  rubber  tubes  shown  in  the  diagram.  There: 
is  thus  a  continuous  liquiel  path  between  the  electrodes,  protected  against 
the  effect  of  vibration  and  forming  really  a  voltaic  ce'll  on  open  circuit. 
The-  calomel  electreule  has  a  potential  of  -f- 0.5000  volt;  it  is  positive' 
and  the  liquiel  negative1.  As  an  example,  the  difference  in  potential 
be't  \vevn  the  two  electrodes  might  be  O.fJ.'JOO  volt,  the  calomel  electrode 


File.  142. — Calomel  electrode  used  to  measure  the  potential  at  a  sirmle  electrode. 

being   positive.     This   would   show   that   the   unknown    potential    was 

-r0.r><;oo  -  o. (i.'-UK)  =    -0.0700  volt. 

Known  Potential  of     Calomel  Kloctrode  —  Difference  in  Potential  =  Unknown 
Potential.      Hence, 

Potential  of  Calomel  Klectnxle.           Difference  in  Potential.  Unknown  Potential. 

~o.r><i(M)                                   o. <;:',(>()  -o.oTOO 

Another  example  would  be: 

Potential  of  Calomel  Electrode.          Difference  in  Potential.      Unknown  Potential. 
-•-().. ")li()0  ().,")()()()  -  O.OtVK) 


n 


17S  MEDICAL    ELECTRICITY    AM)    RONTGEN    RAYS 

source  of  potential.     The  difference  so  found  may  be  regarded  as  the 

potential  of  the  calomel  electrode  in  the  different  calculations. 

'/'//<  //,</<•,„/,„  EI(ctnnli.  This  is  another  standard  electrode  giving 
a  very  definite  potential  and  used  for  measuring  the  potential  of  a 
single  electrode.  It  consists  essentially  of  a  platini/ed  platinum  plate 
half  immersed  in  a  suitable  electrolyte  and  half  surrounded  by  hydrogei 
lias  which  bubble-  up  t  h  rough  the  elect  i'olyte.  The  potential  "f  the  hy- 

drogeii  electrode  in  normal  sulphuric  acid  solution  is  •  0.277.  '1  his  is 
(rss  convenient  to  u-e  and  more  liable  to  error  than  the  calomel  elec- 
trode which  i-  correct  down  to  T'lf  millivolt  or  ,,,'„„,  volt. 

The  Telephone.  The  telephone,  in  addition  to  its  wonderful 
commercial  value,  is  useful  as  a  diagnostic  means  in  detecting  the 
presence  "f  electric  currents  and  in  testing  the  acuteness  of  hearing, 
and  has  some  value  as  a  therapeutic  agent  in  the  application  of  sound 
in  ear  and  brain  diseases. 

The  apparatus  consists  essentially  of  a  transmitter  and  a  receiver, 
and  there  may  be  an  electric  battery.      The  transmitter  i-  used  by  the 
speaker    in    an    ordinary    long-distance    conversation,      \\ords    spoken 
in!  .   h    pi    duce  characteristic   vibrations  in   an   iron  diaphragm,   which 
:-  tnadi    to  timve  toward  and  away  trom  the  end  ot  a  magnet.      As  the 
armature    approaches    the    magnet     the    attraction    between    the    two 
a-es   and    the   strength   of   that    magnetic    pole    is    increased.      The 
::.::L::.'  '    i-  surrounded  by   an  induction  coil   in   which  a  current    is  geii- 
erateil    b\     the    expanding    lines   of    force    produced    by    the    increase  in 
strength   of   that    magnetic    pole.      The   wire   of   this   coil    is   continuous 
thi    two  wires  leading  to  and  from  the  distant    receiver,  and  with 
ndiiction  coi]  of  the  latter.      The  induced  current    travels  through 
i    length  of  this  wire  at   the  rate  of  Iss.OOO  miles  a  second,  and 
-I    instantaneously  sem   through  the  other  part  of  the 
in  .    :  inning    the    in  luciion    coii    of    the    receiver.     There    ii    acts    to 
-•••:._••.•:.    '    at    '    a  tin  el  ic    pole,    and.    therefore,    to   attract   an  iron   dia- 
phragm.      I:,'  agin    ot    the    transmitter    moves    away    trom    the 

•  ,'  _f:.    '    at    thi    •  tin  r  pall   of  each   vihrat  i"M.  and  causes  a  din  limit  ion  of 

ih    in    'hat    po]  lh      magnet.      Thi>    induces   a   current    in    the 

irst    describ  -d.    and    the  effect    of   this   at 

is   to   dl!  '     e   an  racl  i'  >n    exerl  -'d    upon    the    iri  'ii    dia- 

•    .       I  hi  11.-    i  '     vibrations    produced    bv    the    sound    of    1  he 

1  •(•    at     thi     !  ram-mi*  ler    are    accurately    duplicated    by    the 

.       '1  he   vil  il'al  !'  'li-  '  'f   the  la!  "  -T  are  ci  immimi- 

•      sound.-    '.'.  hicll    are    jin    all:, i  '-1     perfect     repro- 

:    .     '        '  .        '      '      •  ,  Ice.          \11     elect  i'ic     bal  !er\      ;  -     \  .   ry     I'ommonlv 

;    •        .       ! '     ->-'  c      l  iiiii     is    ciirrenl  i    t  he    coils    in    t  he 

•/      '  ,  •    '       wire  as  soon  as 

•    '      '•!     I      •      ;•      • ,  ••  '•.    '  •  <   : "     used.      The   magnets   an1 

l  he  current .  and  l  lie  i  •li't  'ct 

in  t  he  1  ratiM!  ;'  '  •  r  i-  to  >  >p  n  luce 

1    Hi .       I  he-e  v;  riat  ion-  are  ri •( >eat  ei  1 

:  ici     vana'  ion-    in    '   ie    -t  r   ngl  h   of 

' .  !>  i  ions   of    i          liap  iragm.      This 

•    '  permanent    magnets  in 

-  I    an  v  bai  i  ei'v. 

Thi     use    of    the    telephone    a-    a    delicate    test,    for    the   proence    of 


DYNAMIC    ELECTRICITY 


179 


electric  currents  makes  it  valuable  in  measurements  of  resistance  and 
of  electromotive  force.  It  is  invaluable  for  rapidly  alternating  voltages, 
for  which  the  various  types  of  galvanometer  and  electrometer  are 
unreliable.  The  telephone  will  detect  differences  as  small  as  To,VoT) 
between  the  potentials  of  two  objects.  This  is  illustrated  on  p.  185. 

The  Telephonic  Build  J'robc.—  Dr.  John  H.  Girdner,  of  New  York, 
was  probably  the  first  to  publish  a  description  of  such  an  instrument. 
A  telephone  receiver  has  one  of  its  wires  connected  with  a  metal  bullet 
probe  which  may,  but  need  not  necessarily,  be  insulated  except  at  its 
tip.  The  latter  is  of  metal.  The  other  wire  goes  to  one  pole  of  a 
battery  of  two  or  three  voltaic  cells  or  to  one  pole  of  a  small  induction 
or  faradic  coil,  the  other  polo  of  which  may  be  held  in  the  patient's 
hand.  The  electric  contact  is  decidedly  bettor  or  the  resistance;  less 
when  the  probe  touches  a  piece  of  metal,  such  as  a  bullet  embedded  in 
the  flesh,  and  a  sharp  click  heard  in  the  telephone  receiver  announces 
the  fact. 

This  method  has  been  applied  by  Kenneth  Bulkley,1  who  attributes 
the  telephonic  bullet  probe  to  Alexander  Graham  Bell.2  He  uses  only 
the  bodily  currents  of  electricity,  no  battery  or  generator  of  any  kind. 
The  telephone  receiver  covering  both  ears  has  a  resistance  of  about  1200 
ohms.  The  probe  is  a  steel  darning  needle  insulated  by  shellac  except 
at  its  point,  and  is  intended  to  pierce  the  tissues  in  various  directions 
until  a  sudden  click  indicates  lessened  resistance  and  greater  current 
on  making  contact  with  a  metallic  foreign  body.  The  other  electrode 
is  a  carbon  pencil  placed  in  the  mouth  or  rectum. 

Ax  a  Text  for  Hearing. — Urbantschitsch  has  devised  the  apparatus 
shown  in  Fig.  143.  This  consists  of  a  telephone  receiver,  which  the 


l-'ij.'.  143.— Urbantschitsch's  trlrphonc  apparatus  for  tilting  hearing. 

patient  holds  to  his  ear,  a  secondary  coil,  with  which  the  telephone  is 
connected  and  which  is  placed  inside  of  two  separate  primary  coils. 
The  latter  are  exactly  similar  and  are  supplied  with  the  same  current 
from  a  battery  or  from  the  electric-lighting  circuit,  the  interruptions 
being  made  inside  a  sound-proof  box.  When  the  two  primary  coils 
are  in  exactly  the  right  position,  the  effect  of  one  upon  the  secondary 
coil  exact Iv 'counterbalances  the  effect  of  the  other,  and  there  is  eom- 


1  Sun:..  ( iyn.,  ami  <  >bst.,  March 
-  The  Lancet,  London.  1  ^i,  1.  1 


ISO 


MKDICAL    KLKCTHICITY    AND    RONTGEN    HAYS 


plete  absence  of  sound  iii  the  telephone,  (hie  of  the  primary  coils  is 
fixed,  hut  the  other  is  movable  by  a  rack  and  pinion.  Moving  this  coil 
toward  the  center  of  the  secondary  coil  causes  more  and  more  secondary 
current  to  l>e  induced,  and  more1  and  more  noise  to  be  produced  in  the 
telephone.  The  point  at  which  the  patient  is  able  to  hear  the  sound 
furnishes  a  mat  hematic  value  for  record  or  comparison. 

It  is  possible  to  u-e  a  single  primary  and  a  single  secondary  coil  in 
the  same  way.  but  they  would  have  to  be  separated  to  an  inconvenient 
distance  in  order  to  secure  complete  absence  of  sound.  \\ith  the  two 
primary  coils  only  two  or  three  inches  of  motion  are  required  to  change 
from  the  maximum  sound  to  complete  silence. 

Fiii'iire  1  1 1  <hows  Brcit  ung's  apparatus  for  the  same  purpose.  There 
is  a  lame  tunin>r-fork  set  in  vibration  by  an  electromagnet  and  inclosed 
in  a  sound-proof  box.  The  telephone  is  excited  by  the  secondary 
current-  in  an  induction  coil,  the  primary  wires  of  which  are  not  con- 


1  14.  -Bn-ii  ung's  telephone  apparatus  for  testing  hearing 


m-eted  with  any  battery,  but  with  electromagnet  coils  placed  near  the 
vibrating  end-  of  the  tuning-fork.  The  back  and  forth  motions  of  the 
-tee]  tuniiiLr-fork  generate  alternating  currents  in  the  primary  coil. 
The  loudne--:  of  tin-  -oiind  in  the  telephone  is  varied  by  moving  the 
secondary  ('"il  nearer  to  or  further  from  the  primary.  The  advantage 
of  thi-  over  the  other  m-trument  is  in  the  fact  that  a  pure  tone  is  pro- 
duced or  sound  coii-Minu:  altogether  of  one  wave  length. 

( 'ases  o|  deaftie-s  are  sometimes  benefited  by  the  application 
ot  -ound  vibration-  by  means  of  such  apparatus  as  the  telephone1 
or  the  phonograph.  Thi.-  may  be  called  a  very  mild  form  of  auditory 
nin+.-H'ii  . 

The  Electric  Conductivity  of  Liquids.  The  rt>nrli/cfirit>i  of  a 
liquid  i  tin  '  tmber  o]  amperes  ni  current  \\hidi  a  cube  of  the  liquid 
me;i-uriii<i  one  centimeter  on  each  side  will  transmit  under  a  pressure 


DYNAMIC    KLK<  TKICITY  IS] 

fall  in  potential  (in  volts)  per  centimeter  of  the  length  of  the  conducting 

path. 

The  conductivity  of  a  liquid  may  be  described  as  the  current  density 
under  unit  potential  gradient. 

The  specific  resistance  is  the  reciprocal  of  the  conductivity,  and  is 
expressed  in  ohms. 

The  conductivity  of  sulphuric  acid  at  its  strength  of  maximum 
conductivity  and  at  a  temperature  of  18°  C.  is  0.739S.  Its  specific 

resistance  is  pp^s  ohm,  or   1.353  ohms.     This  is  the  resistance  of  a 

cube  of  this  liquid  one  centimeter  on  a  side. 

The  specific  resistance  of  a  liquid  is  the  number  of  ohrns  of  resistance 
offered  by  a  cube  of  this  particular  liquid  one  centimeter  on  a  side. 
It  is  found  by  dividing  the  number  of  volts  difference  in  potential  per 
centimeter  of  distance  between  the  electrodes  by  the  number  of  amperes 
per  square  centimeter  of  opposed  surfaces  of  the  electrodes. 

The  resistance  offered  by  any  body  of  liquid  through  which  the 
current  passes  is  expressed  in  ohms.  The  conductance  of  the  same 
body  of  liquid  is  the  reciprocal  of  the  number  of  ohms,  or  1  divided  by 
the  number  of  ohms. 

Mho  is  a  word  coined  by  spelling  ohtn  backward,  and  is  used  in 
giving  a  numeric  value  to  the  conductance  of  a  body  of  liquid  or  of  any 
other  conductor.  The  conductance  expressed  as  so  many  mhos  is 
the  same  as  1  divided  by  the  number  of  ohms  resistance. 

The  conductance  of  a  trough  of  liquid  into  which  two  electrodes 
dip  may  be  found  by  calculation  if  we  know  the  conductivity  of  the 
liquid,  the  surface1  area  of  the  electrodes,  and  their  distance  apart.  Take 
the  case  of  the  sulphuric  acid  solution  referred  to  above.  Its  con- 
ductivity is  0.739S,  and  say  that  the  electrodes  are  plates  10  centimeters 
square  (('.  e.,  each  has  an  area  of  100  square  centimeters),  facing  each 
other  at  a  distance  of  5  centimeters.  The  conductance  will  be  found 
by  multiplying  the  conductivity  ().739cS  by  100.  the  area  of  cross-section 
of  the  conducting  path,  and  dividing  by  5,  the  length  of  the  conducting 
path: 

0.7398X100 

Conductance  14. /9o  mhos. 

o 

The  resistance  of  such  a  trough  of  dilute  acid  would,  of  course,  be 

=  0.0696  ohm. 
14.  /  9() 

Li(jui(l  Resistances. — These  may  be  introduced  into  a  circuit  to  reduce 
the  strength  of  the  current:  and  if  the  area  of  the  two  electrodes  or 
the  distance  between  them  is  adjustable,  a  liquid  resistance  may  be 
used  to  regulate  the  strength  of  the  current. 

The  name  liunid  volt-controller  is  properly  applicable  only  when 
such  a  cell  is  shunt  to  the  circuit  of  utilization. 

An  adjustable  liquid  resistance  is  used  as  a  rheostat  or  as  a  volt- 
controller  in  several  different  types  of  .r-ray  apparatus  to  regulate 
either  the  primary  or  the  secondary  current,  (iaiffe's  transformer  for 
.r-ray  and  high-frequency  currents,  one  ot  the  most  modern  types  oi 
apparatus,  uses  liquid  resistances  in  the  secondary  circuit. 

The  resistance  of  a  liquid  varies  very  greatly  with  its  temperature, 
with  its  concentration,  and  with  its  exact  chemic  composition.  Some 
few  liquids  have  a  conductivity  and  a  temperature  coefficient  which 


1S2  MKDICAL    KLKCTRICITY    AND    RONTGEN    RAYS 

make    them    suitable    for    the    gross    regulation    of   the   current.     The 
resistance  of  aqueous  solutions 'varies  about  2  per  cent,  for  each  degree 

Centigrade. 

Liquid  resistances  are  never  constant,  so  as  to  make  them  suitable 
for  use  in  the  exact  measurement  of  electric  currents.  They  cannot 
take  the  place  of  coils  of  wire  for  this  purpose. 

Pnlarizatin-n  in  Liquid  Rcaintnncat.  -The  flow  of  the  current  is  almost 
entirely  dependent  u p. .n  electrolysis.  The  purest  water  obtainable, 
redistilled  and  preserved  from  contact  with  the  air  in_glass  vessels  of 
as  little  solubility  as  possible,  for  glass  itself  varies  in  solubility,  is 
with  difficulty  electrolysed,  and  has  a  conductivity  of  only  0.04  XlO~6, 
or  O.uoooi  11)01.  i  hi  expo-lire  to  the  air  the  conductivity  of  distilled 
water  ri-es  to  0.07  X  ID"'1,  and  water  is  not  considered  satisfactory 
for  conductivity  if  its  own  conductivity  is  found  to  be  greater  than 
.">  .  li)-''1.  or  o.ooooo").  The  slightest  admixture  ot  any  readily  elec- 
tn>ly/.able  substance  multiplies  the  conductivity  of  water  enormously. 

The  product-  of  electrolysis  collect  upon  the  two  electrodes  and  have 
a  tendency  to  greatly  increase  the  resistance,  especially  if  one  or  both 
products  a.re  gaseous.  The  Wehnelt  interrupter  is  an  example  of  a 


-Mi 

I  bridj* 

I  i-    lt.">.    -Use  of  the  alternating (.•h'ctru'-light  current  in  testing  conductivity  of  a  liquid. 
it  •  ••iiitruller  ari'i  th<-  \Vheat>ti>ne  bridge  are  in  series  with  the  incandescent  lamp. 

liquid  resistance  in  which  the  current  is  actually  rendered  discontinuous 

by  change-  taking  place  at   one  of  the  electrodes. 

The  resistance  of  a  liquid  cell  is,  therefore,  not  always  a  true  indica- 
ti'  in  of  t  he  c,  indue-  ivit  y   <  if  t  he  liquid. 

The  mjlut  an   nf  fiftltirisntitin  is  reduced  by  using  a  rapidly  alterna- 
'::.::   current    and   electrodes   with   -penally   prepared   surfaces. 

Platinized   electrodes   are   prepared   by   immersing  them   in   a  •*>  per 

cent,  solution  ot  platinum  chlond  containing  -4ln  per  cent,  lead  acetate, 

and   -ending  :i   weak  curr<'iil   of  electricity  at    first   in  one  direction  and 

then  in  the  other  tor  about    ten   minute-.      The  surface  ot   the  platinum 

electrode-   become-  coated   with   platinum  black,   which  does  not   allow 

ilate  upon  its  -urtace  to  anv  extent,  and  thus  greatly 

e-     po]      i/.ation.      Palladium     black    deposited     upon    the    surface 

ol    the    e]i-c!i    n|i--    i-    a]-"    an    excellent    depolarizer. 

[lap  '     •:,  ol    the  current,    -o  that    neither  electrode  is  of  one 

p    .      i';.    .•  •:.'-'   '•]       iirh    for  gases   lo  collect    upon    it.    is    a    most     effective 
mead  •  of  pn  •  i/.a!  ion. 

/'''"/  •''  .   ';/  "    LI  1 1  a  nl .       I  hi-   l-  done  bv  ]  (lacing  some 

ble  glas-  or  porcelain   vessel,  immersing  suitable 


DYNAMIC    ELECTRICITY 


183 


the  resistance  offered  by  the  liquid  cell  to  the  passage  of  the  current. 
As  an  ordinary  galvanometer  or  milliamperemeter  will  not  measure 
an  alternating  current,  an  electrodynarnometer  is  used  or,  better  still, 
a  telephone  receiver.  The  telephone  receiver  takes  the  place  which  the 
galvanometer  would  occupy  in  the  ordinary  use  of  the  Wheat  stone 
bridge,  and  indicates  an  exact  balance,  and  consequently  no  current 
across  the  bridge  when  no  sound  is  heard  in  the  telephone. 

The  battery  should  consist  of  only  one  or  two  voltaic  cells  or  dry 
cells.  A  storage-cell  can  be  used  with  a  large  fixed  resistance  in  circuit; 
or  the  alternating  electric-light  current  can  be  used  by  introducing  an 
incandescent  lamp  and  a  volt  controller  (Fig.  146).  The  volt  con- 
troller has  very  little  resistance,  the  object  being  to  yield  a  difference 
of  potential  of  only  two  or  three  volts  between  the  wires  leading  to  the 
Wheatstone  bridge.  The  resistance  employed  in  the  volt  controller 
being  only  two  or  three  ohms,  it  is  necessary  to  supplement  it  by  the 
resistance  of  the  incandescent  lamp  before  it  is  safe  to  turn  on  the  110 
volts  alternating  current.  The  series  lamp-socket  makes  it  a  simple 
matter  to  connect  an  electric  lamp  for  use  as  a  resistance.  The  socket 
has  binding-posts  and  the  lamp  is  in  series  with  any  circuit  which 
terminates  at  A  and  B.  Disconnecting  the  wire  at  A  and  B  or  both 
extinguishes  the  lamp.  A  16-candle-power  lamp  is  screwed  into  the 
socket. 


Fit:.  140. — Vessels  and  electrodes  for  testing  the  conductivity  of  liquids:  a,  For  liquids  of 
great  conductivity;   b  and  c,  for  those  more  resistant. 

The  rate  of  alternation  in  the  electric-lighting  current  is  not  rapid 
enough  to  give  a  clear  sound  in  the  telephone  receiver  and  consequently 
the  electrodynamometer  must  be  employed  with  this  current.  Xo  in- 
duction coil  is  required. 

The  110  volts  direct  electric-lighting  current  may  be  used  in  the 
same  way,  and  a  series  socket  and  volt-controller  form  a  simple  and 
reliable  apparatus  if  one  has  not  a  more  elaborate  apparatus,  such  as 
the  author's  table  for  obtaining  the  galvanic,  faradic,  sinusoidal,  and 
other  currents  from  the  1  10  volts  direct  current. 

The  shape  of  the  vessel  and  the  distance  between  the  electrodes 
should  vary  to  correspond  with  the  conductivity  of  the  different  liquids 
to  be  tested.  A  U-shaped  tube,  Fig.  14t>,  a,  in  which  the  two  electrodes 
are  separated  bv  a  column  of  liquid  several  inches  in  length,  is  suitable 
for  testing  the  conductivity  of  a  liquid  \vluch  is  a  good  conductor.  The 
diagram  h  shows  a  vessel  suitable  for  testing  a  liquid  of  very  poor 
conductivity.  The  electrodes  are  fixed  in  position  by  wires  which  are 


1M 


MKIHt  AL    KI.Kl  THK  ITV    AND    ROXTGEX    HAYS 


sealed  into  irla-s  tubes,  the  latter  being  partly  filled  with  mercury. 
( 'ondtict  im:  wires  dip  into  the  mercury  and  make  perfect  contact. 
The  two  uhi-s  tubes  are  sohdlv  fastened  in  the  hard-rubber  cover  of 
the  jar  and  there  is  another  hole  through  the  cover  for  the  introduction 
of  a  thermometer.  'j'he  ^lass-covered  stem  of  the  loAver  electrode  is 
.-hown  in  the  diagram  as  pa>sing  through  a  hole  in  the  upper  electrode. 

The  diagram  c  shows  still  another  arrangement.  The  two  electrodes 
are  -"lidlv  fastened  in  a  glass  tube.  o])en  to])  and  bottom,  and  can  be 
immersed  in  a  liquid  contained  in  any  sort  of  vessel. 

The  induction  coil  for  use  in  these  measurements  should  have  only 
about  liiuii  turns  of  wire  and  its  vibrating  interrupter  should  give  a 
musical  note  representing  from  •_'.")()  to  1000  vibrations  a  second.  There 


1  iir.  1  17. — \Yheatstone  l>ridu<-  used  tn  measure  conductivity  of  a  liquid. 

1  be  a  -witch  for  turning  the  current  off  when  not  actually  making 
st.  as  the  current  heats  the  liquid.  The  telephone  receiver  should 
i  resistance  of  about  10  ohms.  A  difference  of  T,1,-,0  C.  in  the  tem- 
ire  of  the  liquid  makes  a  difference  of  0.001.  It  may  be  readily 
hat  if  the  measurement  is  to  be  exact  down  to  thousandths,  the 
inu-t  be  at  exactly  the  proper  temperature  and  must  be  kept  there 
hermo-tat . 

e   .--tn  ruin  rd   rcxixtanccfi  used    in  making   the   test    include,    first,  a 
[ch  should  give  any  number  of  ohms  from   1   to   1000 
i.-tment  of  pi  nils  introducing  various  resistance  coils  into  the 
The    longer    re.-istance    coils    should,    of    course,    be    wound    in 
to    reduce   'he   disturbing   effect    of   self   induction  and 
im,    the    first    by    having    the   wire   doubled    upon 
bv  Chaperon's  method  of  winding,   each  layer  ot 
ind   in   the  opposite  direction   from  the  preceding 
.    the    two    other   standard    resistances    are    formed   by 
lance  wire  mi   either  side  nf  an   adjustable  sliding 
•••.    be  a    -traighl    wire  of  pla'inum   iridium  allov  or  of 
l-copper     allov.      1      meter     long     and     about      \ 
.    i'    may  be  a    similar    wire    with    perhaps    only 
in  .    and    it.-    two    end.-    forming    resistance    coils. 
•  -  -pace  in   t  he  mii-1  nicl  ion  <  'i'  the  appal'at  US 
-e    the     measurements    bv     the     Wheatstone 


DYNAMIC    ELECTRICITY 


185 


bridge  are  most  accurate  when  the  t\v<>  parts  of  the  slide  wire  resistance 
are  nearly  equal. 

Figure  147  shows  the  arrangement  of  the  apparatus  for  the  measure- 
ment of  the  resistance  in  the  cell  of  liquid,  and  Fig.  14S  gives  the  cus- 
tomary diagrammatic  representation  of  the  Wheatstone  bridge  and  indi- 
cates the  parts  which  correspond  to  the  present  arrangement. 

Naming  the  different  resistances  DA,  AC,  DB,  and  BC,  according  to 
points  between  which  they  are  placed,  these  are  the  same  in  both  Figs. 
147  and  148.  According  to  the  principle  of  the  Wheatstone  bridge, 


XJ/-     ' 

V  .  B  J 

^  Saffery   $  inc/i/ction   coil       -^ 

Fig.  14s. — Conventional  diagram  of  Wheatstone  bridge  us  used  to  measure  cone 

of  a  liquid. 


iuctivity 


no  current  will  flow  across  from  A  to  B  through  the  telephone  receiver 
if  the  different  resistances  boar  the  following  relation: 

DA  :  DB  :   :  AC  :  BC. 

The  test  is  made  by  setting  the  sliding  contact  at  500,  making  AC 
and  BC  equal;  then,  while  the  current  is  turned  on  and  the  telephone 
held  to  the  ear  and  the  other  ear  stopped,  adjusting  the  plugs  in  the 
resistance-box  until  the  minimum  sound  is  produced  in  the  telephone. 
After  this  the  sliding  contact  is  moved  along  the  resistance  wire  in  one 
direction  or  the  other  until  the  absence  of  sound  in  the  telephone  shows 
that  no  current  is  passing  across  the  bridge.  Then,  from  the  values 
of  AC  and  BC  in  millimeters  and  of  DA  in  ohms  we  find  by  the  usual 
proportion  the  value  of  the  unknown  liquid  resistance  in  ohms.  The 
telephone  forms  an  extremely  sensitive  test  for  the  presence  or  absence 
of  an  interrupted  or  an  alternating  current.  It  shows  as  slight  a 
difference  as  1(I)MU)  between  the  potentials  at  the  two  sides  of  the 
Wheatstone  bridge.  It  consequently  affords  a  very  exact  measure  of 
the  different  resistances.  It  does  not.  however,  indicate  the  direction 
of  the  current  flowing  across  the  bridge,  and  consequently  there  is  no 
mathematic  guide  to  the  direction  in  which  the  sliding  contact  should 
be  moved.  The  latter  is  moved  in  one  direction  at  a  venture  and  the 
effect  upon  the  loudness  of  the  sound  in  the  telephone  is  noted.  ll 


180 


MEDICAL    ELECTRICITY    AND    BONTGEN    RAYS 


the  sound  becomes  less,  it  means  that  the  sliding  contact  is  being  moved 
in  the  riidit  direction,  and  vice  versa. 

The  general  arrangement-  is  exactly  the  same  when  the  direct  110- 
volts  current  with  a  suitable  volt-controller  is  used  to  excite  the  small 
induction  mil. 

An  electrodynamometer  must  he  used  instead  of  the  telephone 
receiver  if  the  slowly  alternating  electric-light  current  is  used,  as  this 
does  nut  iiive  a  sat  isfactorv  sound  in  the  telephone. 

T"  recaj)itulate.  A  unidirectional  current  cannot  be  used  in 
measuring  the  resistance  of  a  liquid  because  of  electrolysis  and  rapid 
polari/ation.  An  ordinary  galvanometer  or  railliampcrcmctcr  will  not 
work  properly  with  an  alternating  current.  The  telephone  receiver 
has  been  found  excellent  for  the  purpose  of  detecting  the  presence  of  a 
curn  nt :  and  the  best  current  for  the  purpose  is  the  secondary  current 
fn>m  a  small  induction  coil  of  1000  turns  actuated  by  one  or  two  dry 
cell- or  by  an  equivalent  direct  primary  current  from  any  other  source. 
The  ,-ei-ondarv  current  from  the  induction  coil  is  a  rapidly  alternating 

i  ilie. 

One  practical  application  of  this  test  in  medical  electricity  is  in 
determining  the  electric  conductivities  of  the  urine  and  other  animal 
fluids  which  vary  in  morbid  states.  Another  is  in  the  measurement 
of  the  resistance  of  the  human  body.  When  electrodes  are  applied 
to  a  cutaneous  or  a  mucous  surface,  or  actually  puncture  the  tissues, 


to  do  with  an  electrolyte  with  some  of  the  same  characters  as 
those  of  the  liquids  described  in  the  last  few  pages,  but  even  more 
complex.  The  resistance  encountered  by  a  direct  continuous  current, 
tor  instance,  changes  very  much  after  the  current  has  been  flowing 
for  a  time,  and  is  greatly  modified  by  the  passage  of  a  faradic  current. 
A-  in  the  case  of  liquids  in  glass  jars  the  resistance  to  the  flow  of  the 
current  through  the  body  is  lessened  in  proportion  to  the  size  of  the 
electrodes.  The  knowledge  of  the  effect  of  varying  conditions  upon 
the  resistance'  ot  the  human  body  is  of  great  importance  as  a  guide  to 
application  of  the  proper  current:  voltage,  alternating  or  direct  char- 
acter,  frequency,  and  sometimes  amperage,  all  have  to  be  considered. 
Currents  and  Derived  Circuits. — An  electric  current  divides  up 
atnontr  two  or  more  conducting  paths  in  proportion  to  their  conduc- 
1  h"  latter  are  inversely  proportional  to  their  resistances. 
I''  rhe  diair: 'am  Kit:.  110  a  current  ('  is  supposed  to  be  passing  through 
portion  of  the  circuit  under  the  influence  of  an  electro- 


DYNAMIC    ELECTRICITY 


187 


Then  the  current  C,  through  the  undivided  part  of  the  circuit,  and  c' 
and  c,  through  the  two  branches  or  derived  circuits,  are  found  by  the 
following  equations: 


=     K 

Rr'  -     Rr'    -    r'   r'2 


=      E 


Rr'  +    Rr*    +    r'  r2 


Rr'  +    Rr'    +  r'  r2 


The  .current  C  through  the  undivided  part  of  the  circuit  is,  of  course, 
equal  to  the  sum  of  the  currents  c'  and  r,  into  which  it  splits  at  a  certain 
point. 

The'  currents  c'  and  r  through  the  two  divisions  of  the  circuit  (jr. 
technically,  through  the  two  derived  circuits,  are  inversely  proportional 
to  their  resistances.  The  current  in  the  first  derived  circuit  is  to  the 
current  in  the  second  as  the  resistance  in  the  second  is  to  the  resistance 
in  the  first.  If  the  resistance  in  the  first  derived  circuit  is  twice  as 
great  as  in  the  second,  the  current  in  the  first  circuit  will  be  half  as 
great  as  in  the  second. 

\AMM/V 


vwwwvwv 


Fit:.  l.~>0.' — Princi|)al  circuit  and  shunt  circuit. 

The  resistance  R  is  supposed  to  include  the  internal  resistance  of 
the  battery  as  well  as  that  of  the  rest  of  the  undivided  part  of  the 
circuit. 

Another  case  which  must  be  alluded  to  is  when  there  seems  to  be 
no  undivided  circuit,  as  in  Fig.  151.  The  two  derived  circuits,  it  is 
true,  do  spring  directly  from  the  poles  of  the  battery,  but  the  current 
through  the  battery  itself  is  an  undivided  one  and  is  equal  to  the  sum 
of  the  currents  through  the  two  derived  circuits.  The  latter  currents 
are  inversely  proportional  to  the  resistances  in  the  two  derived  circuit-. 
The  resistance  R  of  the  undivided  circuit  is  simply  the  internal  resist- 
ance of  the  batterv. 


IBS 


MKIIITAL    KLKCTRICITY    AND    ROXTGEN    HAYS 


Fimire  1  HI  .p.  ISO)  is  diagrammatic  of  every  case  in  which  there  are 

one  Dimple  ami  two  derived  circuits,  it  being  understood  that  the 
simple  circuit  -oinetiines  includes  the  battery  alone  and  sometimes  the 
battery  and  an  undivided  portion  of  the  circuit  connected  with  one  or 
with  each  pole.  The  resistance  H  of  the  simple  circuit  may  be  only 
the  internal  resistance  of  the  battery,  or  if  there  are  portions  of  a  simple 
circuit  connected  with  one  or  both  poles  of  the  battery,  it  will  include 
t  heir  resistances  also. 

Anii    nunibtr  <>f  r/cn'm/  circuit*  would  be  represented  by  a   corre- 


Fig.  !.">!. — Two  circuits  starting  from       Fig.   loL'. — Single  circuit  at  one  pole  of  hat- 
thc  liattery.  tery  and  divided  circuits  at  the  other. 

sponding  number  of  branching  lines.  The  current  through  the  simple 
circuit  is  eijual  to  the  sum  of  the  currents  into  which  it  splits  in  the 
derived  circuits.  The  division  of  the  current  between  the  latter  is 
inversely  proportional  to  their  resistances. 

The  conductivity  of  any  circuit  is  the  reciprocal  of  its  resistance. 

It  the  resistance  is  /-'.the  conductivity  is      .     The  combined  conductiv- 

/' 

iiy  of  several  parallel  conducting  paths  or  derived  circuits  is  the  sum 
of  the  individual  conductances  or  the  sum  of  the  reciprocals  of  their 
individual  resistances.  Thus,  if  the  resistances  in  three  derived  cir- 


R  E 

x — mm — IH 


Fig.   154. — Loop  starting  and  ending 

"     point    and    not          at    tlir   >ame.   point   of  a   circuit   and   there- 
fore transmit  t  ing  no  current. 

••if  combined  conductance  is    ,  .       .    .;  and   if  the 

/'       /••'      r! 

nint  ,-,,,, ,/,,•/;.•///  is  tliree  times  as  much  as 

"lieoi    these   derived   circuits.       The  joint  rcsixt- 

ill('l  derivi-d  cii-cuits  is  e((ual  to   1  'divided  b 


DYNAMIC    ELECTRICITY  IS'.) 

?•-  (Fig.  149,  p.  180),  their  joint  conductance  =   ,+  .,;   the 


,  •>  /  2 

r      r     /•      /•- 

77ir  /om/  rcxixtonce  of  tiro  derired  circuits  ?'.s  equal  to  the  product  of 
their  /vW,s7am,'f.s'  dirided  h//  the  stun  of  their  rexixta>tcc*.  When  there  are 
two  derived  circuits  and  the  resistance,  r,  of  one  is  known,  we  may 
calculate1  the  resistance  r'  required  in  the  other  derived  circuit  in  order 
to  produce  a  joint  resistance,  R',  by  the  formula: 


The  total  resistance  of  a  circuit  with  two  derivations  r'  and  r2  and  a 

resistance  R  in  the  simple  circuit  is  =  R+   ,       .,,  or   =  R-<-"R'. 

/'  —  /" 

A  valuable'  application  of  this  formula  is  in  determining  the  relation, 
between  the  resistance  in  a  galvanometer  and  in  a  shunt. 

It  seldom  happens  that  a  galvanometer  is  placed  in  a  simple  circuit 
so  that  all  the  current  will  pass  through 
it.  One  reason  for  not  doing  this  is 
that  the  galvanometer  is  usually  so  sen- 
sitive that  any  ordinary  current,  strong 
or  weak,  will  produce  the  maximum  de- 
viation and,  therefore,  such  a  current 
must  l)o  divided  by  10  or  100  or  1000  to 
come  within  the  working  limits  of  its 
indicator.  The  resistance  of  the  gal- 
vanometer is  usually  great  and  it  would 

I'itr.  !•").").  —  Relation  between  rc- 
invplve    a   waste    of   power   and   an    till-       ,;,,,„„,.  in   a  galvanometer  and  its 

desirable  generation  of  heat  if  all  the     shunt. 
current  were  sent    through  it.     A  gal- 
vanometer, therefore,  practically  always  forms  a  derived  circuit,  while 
a  shunt  forms  another  parallel  derived  circuit.     The  resistance  in  each 
is  usually  so  calculated  that  the  multiplying  power  of  the  shunt  is  either 
10  or  100  or  1000:  and  very  often  these  relations  are  adjustable,  so  that 
with  weaker  cm-rent s  a  lower,  and  with   stronger  currents   a  higher. 
multiplying  power  is  used. 

The  ordinary  needle  galvanometer  undergoes  deflections,  which,  with 
moderate  angles,  are  directly  proportional  to  the  strength  of  the  current: 
and,  having  once  found  the  degree  of  sensitiveness  of  the  instrument, 
it  can  be  used  as  a  milliamperemoter.  To  calculate  the  number  of 
amperes  indicated  by  one  degree  of  deviation,  divide  the  number  of 
volts  of  electromotive  force  yielded  by  the  Daniell  cell  by  the  total 
ohms  of  resistance,  internal  and  external,  in  the  circuit,  which  results 
in  one  degree  of  deviation. 

The  wire  in  an  astatic  galvanometer  varies  in  size  and  in  the  number 
of  turns  according  to  the  currents  which  it  is  designed  to  measure.  The 
usual  instrument  for  measuring  voltaic  battery  currents  consists  of 
about  SOO  turns  of  insulated  copper  wire  about  /.  millimeter  or  Ti-0-  inch 
in  diameter. 


MKim'Al.    Kl.KCTHH  ITY    AND    RONTGEN    KAYS 

Such  instruments,  of  course,  have  great  electric  resistance,  and  even 
when  .-hunted  so  that  the  joint  resistance  of  the  galvanometer  and 
-hunt  i-  only  one-tenth  or  one-hundredth  that  offered  by  the  galvan- 
ometer when  un-hunted:  this  joint  resistance  is  still  so  large  that  it  must 
be  accurately  known  and  taken  into  account  in  all  the  above  measure- 
ment-. Thi-  re-i-tance  may  be  obtained  from  the  table  on  p.  219  if 
the  diameter  and  the  length  of  the  wires  in  the  galvanometer  and  the 

•  are  known. 

A   needle   galvanometer   is   rendered   ballistic   or   is   damped   by   the 

addition  of  brass  to  the  needle.      This,  by  its  weight,  causes  the  needle 

i|uickly   to  assume  a   position   of  rest    instead  of  oscillating  back  and 

like  a  pendulum  before  finally  coming  to  rest   in  the  position  in 

influence  of  the  current  tends  to  place  it.      A  needle  galvan- 

ter  n    i.-t   always  be  held  in  a  horizontal  position. 

An\  in  edle  galvanometer  in  which  the  needle  is  of  large  size,  perhaps 

ng  as  rlu-  diameter  of  the  coil,  and  in  wliich  the  coils  of  wire  are 

:   parallel  with  the  meridian  and  hence  with  the  needle  before  an 

ctirrenl    i-  turned  on,  will  undergo  deviations  in  which,  within 

<    '    in  limits,  the  si  ivngth  of  the  current  is  pro  port  ional  to  the  number 

1  hompson's  Lord  Ravleigh's)  mirror  galvanometer  is  used  to 
mi  a.-uiv  I  he  smallest  currents,  as  in  testing  the  insulation  of  submarine 
cables  and  in  observations  upon  animal  and  vegetable  electrical  currents. 
I'  has  a  large  coil  of  many  thousand  turns  of  the  finest  copper  wire, 
and  a  magnetic  needle  \vliich  is  a  piece  of  the  hair-spring  of  a  watch, 
about  ;  inch  in  length.  This  carries  a  very  small  mirror  and  is  sup- 
:  .'  side  the  coil  bv  a  fine  silk  thread.  A  rav  of  light  is  reflected 


tid    shows    as    a    \\hite    spot   <>n  a  graduated  scale  '.) 
\\  •    liLri;t   .-pot    i-  at    the  /.ei'o  mark  the  instrument 

currents,      \\iihin  the  ordinary  limits  of  the  scale 
ihe  cnrreni    is  directly  pi-o])ort ional   to  the  amount   of 
:  :   each  subdivision  on  the  scale  is  found   in  the 

ilue   of  cadi    degree  in    the  ordinary  needle  galvan- 

Tan^ent   Galvanometers.      These  are  galvanometers  in   which  the 
'    i-  proportional  not   to  the  number  of  degrees  of 
MI    tin     l  angeni    of    t  he   angle   of   deviat  ion.      A 
!   '•'.'..   1  ")<•      ".  i  this   difference   deal1. 

a  line  i  Irawn  t  com  <  me  em  1 
'    a    tangent    in   t  he  curve     i.  < ..  at    a  right 
•out  intied  until  it   Mit  ersecl  s  the 
•    '    e   other   -ide   of   the   angle. 


DYNAMIC    ELECTRICITY  1(.)1 

No  current  could  be  strong  enough  to  produce  a  deviation  of  <)() 
degrees.  A  tangent  galvanometer  is  used  for  measuring  currents  of 
low  potential,  but  considerable  quantity.  It  consists  of  a  vertical 
copper  ring  which  is  placed  parallel  with  the  magnetic  needle  and  which 
is  to  transmit  the  current,  and  surrounds  a  magnetic  needle  with  a 
graduated  circle  beneath  it.  It  is  usually  graduated  in  degrees  and  the 
tangents  have  to  be  looked  up  in  a  table;  but  it  would  be  practicable 
to  have  tin1  tangent  values  marked  upon  the  scale.  To  give  correct 
values  the  needle  in  a  tangent  galvanometer  should  not  be  more  than 
one-twelfth  or  one-tenth  as  long  as  the  diameter  of  the  copper  ring. 

The  Sine  Galvanometer. — This  is  a  needle  galvanometer  by  which 
the.  strength  of  the  current  is  indicated  by  the  sine  of  the  angle  of 
deviation  instead  of  by  the  number  of  degrees  of  circular  measure. 
The  sine  of  an  angle  or  of  an  arc  of  a  circle  is  the  line  drawn  from  one 
end  of  the  arc  perpendicularly  to  the  radius  which  terminates  in  the 
other  end  of  the  arc.  In  Fig.  157,  a---d  is  the  xine  of  the  angle  b  or  of  the 
arc  a-c.  In  a  sine  galvanometer  there  is  the  usual  magnetic  needle 
moving  over  a  horizontal  circle  graduated  in  degrees — 360  degrees  in 
all.  This  circle  and  the  magnetic  needle  are  fastened  at  the  center  of  a 
vertical  ring  around  which  are  several  turns  of  heavy,  insulated  cop- 
per wire,  through  which  the  current  is  to  be  passed.  The  whole  is 
supported  on  the  vertical  axis  of  a  horizontal  circle,  forming  its  base 
and  around  which  it  can  be  turned.  In  measuring  an  electric  current 
the  vertical  coil  of  wire  is  first  placed  in  the  plane  of  the  meridian,  and, 
therefore,  parallel  with  the  magnetic  needle,  the  current  is  then  turned 
on  and  the  vertical  coil  is  turned  to  a  position  parallel  with  the  mag- 
netic needle.  The  needle  is  now  at  a  certain  angle  from  the  north  and 
south  direction  under  the  influence  of  a  current  which  in  this  new  posi- 
tion exerts  its  force  at  an  exact  right  angle  to  the  direction  of  the  mag- 
netic needle.  The  strength  of  the  current  under  these  conditions  is 
proportional  to  the  xine  of  the  angle  of  deviation.  The  sine  galvan- 
ometer is  suitable  for  very  heavy  currents. 

The  tangent  and  sine  galvanometers  both  give  readings  which  uive 
directly  only  the  comparative  strength  of  different  currents.  To  obtain 
absolute  values  in  amperes  or  milliamperes  it  is  necessary  to  ascertain 
the  degree  of  sensitiveness  of  each  instrument  by  experiment  with  an 
electric  current,  just  as  in  the  case  of  the  ordinary  galvanometer. 

The  Limits  of  Accuracy  of  Galvanometers.  The  current  strength 
as  indicated  by  a  tangent  galvanometer  i>  more  exactly  proportional 
to  the  tangent  of  the  angle  of  deviation  when  that  angle  is  about  -\~) 
degrees  than  when  the  angle  is  either  much  larger  or  much  smaller. 

\\ith  all  galvanometers  the  more  nearly  an  angle  of  (10  degree.-  is 
approached,  the  less  relation  there  is  between  the  current  strength 
required  to  produce1  that  degree  of  deflection  and  anv  geometric  func- 
tion of  the  angle  produced.  In  such  a  case  either  to  measure  the 
current  or  test  the  sensitiveness  of  the  galvanometer  it  will  be  necessan 
to  use  a  source  of  low  potential  or  to  shunt  the  galvanometer,  so  that 
only  a  small  fraction  of  the  current  will  pass  through  it. 

Any  galvanometer  can  be  tested  as  to  its  degree  of  sensitiveness  b\ 
placing  it  in  t  he  same  circuit  with  a  .-tandard  galvanometer  and  bat  tery. 

Amperemeters  or  Ammeters  and  Milliamperemeters  or  Mill- 
ammeters.  These  are  galvanometers  \\hich  are  irraduated  by  the 
manufacturer  in  amperes  or  milliamperes,  instead  of  degrees.  Thev 


192  MKr.l'-.U.    KI.KeTKHTFY    AND    ROXTGEX    HAY'S 

are  usually  -hunted,  and  the1  graduations  on  the  scale  indicate  the  te)tal 
current  through  the  galvanometer  and  its  shunt.  The  milliampereme- 
ters  -oM  for  electrotherapy  frequently  have1  two  or  more  shunts  of 
different  resistance,  and  in  this  case  there  is  a  switch  by  which  one  e>r 
the  other  caii  be  introduced.  Numbers  to  which  the  handle  of  the 
-witch  point-;  indicate  the  number  by  which  the1  dial  number  must  be 
multiplied  to  Lrive  the  combined  current  through  the1  milliamperemeter 
and  -hunt.  Thus,  in  one  position  of  the  switch  the  numbered  divisions 
on  the  dial  may  indicate  milliamperes  and  the  ten  subdivisions  of  each 
repre.-ent  tenth-  of  a  miiliampere.  The  milliamperemeter  may  then 
measure  currents  from  ,',,  to  ">  milliamperes.  In  another  position  of 
the  -witch  indicated  by  "  •  10")  the  numbers  on  the  dial  are  to  be 
mult iplii  d  bv  l en,  and  each  numbered  division  represents  10  milliamperes 
while  the  ten  subdivisions  of  each  of  these  indicate1  milliamperes.  The 
ineteT  mav  then  register  from  one  to  fifty  milliamperes.  In  another 
po-iti"ii  of  the  -witch  (indicated  by  "X  100")  the  figures  on  the  dial 
are  to  be  multiplied  by  100:  each  numbered  division  indicates  100 
milliamperes  and  each  of  the  smaller  subdivisions  indicates  10  milli- 
ampeivs.  The  currents  measured  vary  from  10  to  o()()  milliamperes. 
nother  position  of  the  switch  (markeel  "out")  inelicates  that 
the  current  does  not  pass  through  the1  milliamperemeter  at  all.  This 
is  for  use  in  experimenting  (not  upon  a  patient,  but  upon  some1  other 
conductor)  with  currents  of  unknown  strength,  and  which  might 
damage  the  milliamperemeter.  The1  arrangement  of  multiplying 
powers  described  above1  is  the  one  adopted  by  the  author  for  the  milli- 
amperemeter which  measures  all  the  different  currents  applied  to  the 
patient  from  the  voltaic,  faradic,  tie1  Watteville1,  ami  sinusoidal 
apparatus.  It  should  be  stated,  however,  that  the  galvanometer 
referred  to  is  not  of  the  magnetic  ne-eelle  type,  but  etf  the1  movable1  coil  or 
d'. \rsonval  type. 

The  d'Arsonval  Movable  Coil  Galvanometer  (Figs.  loS  and  loO). 

This    instrument    consists    of    a    powerful    permanent    magnet    and    a 

:reely   suspended   coil  of  fine  wire,   through   which  the1  electric  cunvnt 

measured  passes.     The  directive1  force1  is  of  the  same  nature1  as 


in  the>  rase  of  the  magnetic  needle  Lr:dvanometer;  it  tends  to  place  tin1 
tnatrnet  and  the  coil  at  ritrht  anirle-  to  each  other,  and  does  so  in  thi- 
i-a-e  by  moving  the  coil.  The  two  poles  of  the  magnet  are  concave1 


DYNAMIC'    KLKCTKICITY  193 

atul  close  together,  and  enclose1  ;i  cylindric  space  in  which  the  coil  is 
pivoted  so  as  to  he  free  to  move  in  either  direction,  hut  aKvavs  in  I  lie 
plane  of  the  horseshoe  magnet.  The  meter  may  he  placed  in  anv 
position,  and  this  makes  it  very  much  more  convenient  than  the  mag- 
netic needle  galvanometer.  The  movable  coil  is  made  of  many  turns 
of  fine  insulated  wire1  wrapped  around  a  metallic  framework  and  con- 
tains a  soft-iron  core.  The  directive  influence  becomes  manifest  the 
moment  the  current  begins  to  traverse  the  turns  of  wire  in  the  coil 
and  it  tends  to  place  the  coil  at  a  right  angle  to  the  direction  of  the 
lines  of  force  in  the  magnetic  field.  This  motion  is  opposed  by  the 
traction  of  the  two  spiral  springs  of  zinc  wire  which,  when  no  current  is 
passing,  keep  the  coil  exactly  parallel  with  the  magnet,  and  the  indicator 
needle  carried  by  the  coil  exactly  at  the  zero  mark. 

An  improvement  over  the  two  spiral  traction  springs  consists  in  a 
single  spring,  like  the  hair-spring  of  a  watch,  coiled  in  a  flat  spiral.  The 
spring  is  so  adjusted  that  when  it  is  not  subjected  to  any  outside  influ- 
ence it  holds  the  coil  and  indicator  exactly  at  the  zero  mark.  It  exerts 
a  gradually  increasing  pressure  as  the  coil  deviates  in  one  direction  or 
the  other  under  the  influence  of  the  electric  current.  The  moment 
the  current  ceases  to  flow,  the  spring  brings  the  indicator  back  to  the 
zero  mark.  The  direction  in  winch  the  coil  turns  depends  upon  the 
direction  of  the  current,  and  the  connection  of  the  milliamperemeter 
with  the  battery  must,  of  course,  be  such  that  a  deviation  toward 
the  -f  mark  will  occur  with  a  positive  current.,  and  vice  versa.  The 
scale-  may  begin  with  the  zero  mark  at  the  extreme  left  hand,  and  in 
this  case  the  connections  must  be  right  in  order  to  get  any  reading  at 
all.  If  the  connections  are  wrong  and  the  milliamperemeter,  therefore, 
is  reading  backward,  the  simplest  plan  is  to  unfasten  the  two  wires,  one 
leading  to  it  from  the  battery  and  one  leading  from  the  milliampere- 
meter to  the  patient  or  apparatus,  and  change  their  connections. 

The  directive  influence  is  almost  entirely  that  of  the  permanent 
magnet,  and  the  movable  coil  is  relatively  very  little  affected  by  the 
earth's  magnetism.  This  is  the  reason  that  a  d'Arsonval  milli- 
amperemeter works  equally  well  in  any  position. 

The  angle  of  deflection  is  not  easy  to  accurately  calculate  and  the  in- 
strument is  usually  graduated  by  comparison  with  a  standard  one  in 
the  same1  circuit.  "With  a  milliamperemeter  registering  from  0  to  o 
milliamperes,  the  space  on  the?  scale  between  0  and  1  is  1|  times  as  long- 
as  the  space  between  4  and  o. 

The  currents  induced  in  the  metal  framework  upon  which  the  coil 
is  wound  tend  to  make  the  d'Arsonval  milliamperemeter  "dead-beat"' 
or  to  cause  the  indicator  to  promptly  come  to  rest  at  the  angle  of 
deflection  corresponding  to  the  strength  of  the  current. 

The  d'Arsonval  amperemeter  is  the  same  instrument,  but  designed 
to  measure  heavier  currents,  its  divisions  indicating  amperes  instead 
of  milliamperes. 

The  usefulness  of  the  different  shunts  in  varying  the  multiplying 
power  is  the  same  as  with  the  magnetic  needle  galvanometer. 

The  voltmeter  is  simply  a  galvanometer  with  a  very  great  resistance 
and  graduated  in  volts  required  to  produce  the  different  deviation-. 
It  is  connected  directly  with  the  two  terminals  of  the  generator  and  not 
at  all  with  the  patient  or  apparatus  supplied  with  current. 

The  Electrodynamometer.  This  is  an  instrument  for  measuring 
13 


1U4 


MKDICAL    KLKCTHHMTY    AND    RONTGEN    KAYS 


electric  currents  l>y  the  repulsion  that  exists  between  currents  of  elec- 
tricity passing  in  an  opposite  direction   through  two  parallel  wires  or 

parallel  parts  of  the  same  wire.  The  form  in- 
vented l>y  Siemens  consists  of  a  vertical  coil  of 
heavy  insulated  wire  IT,  and  a  single  U-shaped 
piece  of  wire  /'•',  suspended  over  this  by  a  spiral 
spring  with  a  knob,  x,  at  the  top.  by  which  the 
wire  loop  can  be  turned  in  either  direction  later- 
ally. And  this  knob  turns  an  indicator  z  over 
a  graduated  scale  N.  The  wire  ic'  also  carries 
an  indicator  ,:' ,  which  passes  over  the  scale  N. 
The  current  enters  the  coil  at  a  binding-post, 
K,  and  leaves  the  coil  where4  the  other  end  of 
the  wire  dips  into  a  vessel  of  mercury.  It  then 
enters  the  single  loop  ir' ,  and  leaves  that  at 
another  vessel  of  mercury,  from  which  again  it 
passes  by  a  short  wire  to  another kbinding-post 
where  it  leaves  the  meter.  The  adjustment  of 
the  different  parts  is  such  that  when  no  current 
is  passing,  both  indicators  point  to  the  zero 
mark  on  1  he  scale.  When  the  current  is  turned 
on.  the  suspended  loop  ir'  is  repelled  and  tends 
to  be  rotated  and  the  knob  x  is  to  be  turned 
sufficiently  to  make  the  action  of  the  spiral 
spring  keep  the  single  loop  w'  in  its  original  posi- 
tion  and  its  indicator  ?J  at  zero.  The  extent  to 
which  the  knob  xmust  be  turned  is  proportional 
to  the  square  of  the  current  strength.  The  scale 
may  be  marked  in  amperes  after  its  degree  of 
sensitiveness  has  been  tested  by  the  manufac- 
turers; or  it  may  be  marked  in  degrees  of  a  cir- 
cle, and  each  reading  will  then  require  a  calcula- 
tion  based  upon  the  strength  of  current  which 
has  been  found  to  be  indicated  by  a  deviation  of 
one  degree.  The  elect  rodynamometer  is  in- 
rement  of  heavy  currents  used  in  electric  light- 
able  in  almost  everv  wav  than  the  d'Arsonval 


1  Hi-     MEASUREMENT    OF    ELECTROMOTIVE    FORCE 

Quadrant  Electrometer.-  The  electromotive  force  of  a   single  cell, 
-ry,  or  of  :i  iienerator  of  any  kind  may  be  found  by  means  of  a 
ich   i-    an    instrument    dependent    upon   the 
f  two  charged   bodies:  attraction  when   the 
ivpuUioii  when  they  are  similar.     A  metallic 
-erlioiis  by  two  diameters  at   right   angles  to  each 
tioii-   are   fa-tened   on   in-ulated   glass  supports  so 
i1  -aine  plane,  l>ut  are  -lightly  separated  from  each 
Irani    i-  connected  \\ith  i  he  one  directly  opposite  by 
t!,-it    aluminum    needle   i-  suspended   over  these 
1 1  wire  from  I  he  inner  coat  of  an  in  vert  e<l  Ley  den 
Leyden  jar  is  grounded,  while  a  conducting 
to    connect     the    inner    eo;it     with    a    source    ol 


DYNAMIC    KLKCTHICITY  195 

electromotive  force.  The  needle  is  to  be  adjusted  so  that  when  the 
needle  and  all  the  quadrants  are  in  the  same  electric  state,  the  needle 
is  at  rest  above  and  parallel  to  one  of  the  diametric  slits  between  the 
quadrants.  When  the  needle1  and  one  pair  of  quadrants  are  similarly 
charged  and  the  other  pair  of  quadrants  are  oppositely  charged,  the 
needle  deviates  from  its  original  position.  Kaeh  end  of  the  needle 
turns  away  from  the  quadrant  which  is  similarly  charged  and  toward 
the  quadrant  which  is  oppositely  charged.  It  takes  a  certain  amount 
of  force  to  twist  the  wire  by  which  the  needle  is  suspended,  and  the 
extent  to  which  the  needle  deviates  is  proportional  to  the  electro- 
motive force.  The  deviation  is  so  slight  that  it  is  best  observed  by  the 
reflection  from  a  tiny  concave  mirror  fastened  to  the  needle  and  focusing 
the  light  from  a  lamp  upon  a  screen  about  a  yard  away.  One  pole  of 
the  standard  battery  is  connected  with  one  pair  of  these  quadrants  and 
with  the  internal  coat  of  the  Leyden  jar.  The  other  pole  of  the  standard 
battery  is  connected  with  the  other  pair  of  quadrants,  which  must  be  kept 
insulated.  A  careful  note  is  made  of  the  degree  of  deflection  produced; 
and  then  the  effect  of  the  unknown  battery  is  tried.  The  electromotive 
force  is  proportional  to  the  degree  of  deflection.  The  instrument  may 
be  graduated  in  volts  by  the  manufacturer  or  he  may  furnish  a  "con- 
stant" from  which  the  electromotive  force1  indicated  by  any  degree  of 
deflection  may  be  calculated.  E  =  fl  X  constant  (<l  being  the  number 
of  degrees  in  the  observed  angle  of  deflection,  the  ctnixtd-nt  being  the 
number  of  volts  indicated  by  one  degree  of  deflection  and  E  the  elec- 
tromotive force  of  the  cell). 

The  Equal  Deflection  Method. — By  this  method  we  note  the 
deflection  in  a  milliamperemeter  produced  by  a  standard  cell  of  known 
electromotive  force  through  a  certain  resistance,  and  then  substitute 
for  the  standard  cell  the  battery  or  other  generator  whose  electromotive 
force1  is  te>  be*  measured.  The  resistance  is  now  varied  until  the1  milli- 
ampeMvnieter  shows  an  equal  deflection,  and  hence1  the1  same1  cunvnt  as 
in  the1  first  observation.  The-  electromotive  fe>rce  is  directly  propor- 
tional to  the  resistance  when  the1  currents  are  equal. 

The  Potentiometer. — This  is  an  arrangement  of  apparatus  for 
measuring  the1  difference  in  potential  between  any  twe)  points,  such  as 
the1  pole's  of  a  battery,  and  acts  equally  we'll  whether  the1  battery  is  on 
open  or  cle)seid  ciiruit. 

It  consists  of  resistance's,  a  standard  cell,  and  a  galvanometer,  and 
its  principle'  is  the  balane'ing  of  the1  electromotive  force  of  the  one1 
against  that  of  the1  other  in  sue-h  a  way  that  no  e'urrent  flows  through 
the  galvanometer. 

Figure1  19(i  shows  the  arrangement  diagrammaticallv. 

The'  wire1  a-b  has  a  unifeirm  thickness  and  considerable  resistance', 
and  the  resistance  of  any  two  portions  of  it  is  pmportional  to  their 
length  measured  upon  a  me'tal  scale  over  which  it  is  stivtche'd.  At  its 
two  end-  this  wire  is  connected  by  a  wire  of  very  small  resistance  with 
a  constant  batte'ry,  such  as  a  single  storagv-cell  .1.  The  differene'e  in 
potential  betwee'ii  the'  two  ends  of  this  wire  will  be'  about  2  volts:  r  is 
the  cell  which  is  to  be  te'sted.  and  it  must  have1  an  electromotive  force 
less  than  that  of  the  battery  .1.  The  positive1  pole  of  c  U  connertcu  to 
<i.  the  positive  end  of  the  re-iMance  wire:  and  the  negative  pole,  after 
fir-t  passing  through  the  galvanometer  ;/.  make's  a  slide  cemtact  with 


the  resistance  wire  ai  the  point  .r.     The  circuit  a  r  </ .r  is  in  shunt  to  the 

circuit   //  .r,   .-iiiil   if  il   were  tin!   fur  llif  electromotive  force  of  ihe  cell  r. 
'.•  \\  i mill  (low  t  h rough  <M-  i/.r  in  consequence  of  a  certain  fraction 
n|     the    electromotive    force    iif    the    Morale-cell     .1.      'I'he    difference    in 
p  iii  iitial   between  n   Mini  .''  \:iries  with  the  resistance  between   the  two 
and    i-    regulated    liy    moving    the    >lidmg   contact.      The   elect  roinotive 
forci    !vp:v>eiited   tu    the  ilitTerence  in   potential  between  '/  and  .r.  and 
L:  :o  produce  :;  current   through  <i  r  </  .r  is  opposed  by  the  electro- 
motive  force   of   the   cell   r,    which    tends   to   produce   a   current    in   the 
oppn-iti   direct  ion  t  drouth  ./•  </  r  </.     The  sliding  con  tad  is  adjusted  until 
the  galvanometer  shows  that   no  current   is  passing  through  the  circuit 
A  standard  cell  with  a  known  electromotive  force,  such  as  the 
i  I:    k  or  tin    cadmium  cell,    is  then   substituted   at    *  for  the  unknown 


Fin.  Itil.—  The  potontiomotcr. 

1  c  by  turning  the  contact  key  /;.     A  point  y  is  then  found,  by  the 

ling   contact,    where   no   current    passes   through    the   galvanometer. 

i -nee  ::.  poti  nlial  between  u  and  ./•  is  equal  to  1  he  elect  roinotive 

•'•  o]  the  cell  <•;  and  that  between  n  and  '/  to  the  electromotive  force 

tandard   cell   .-.      These   two  are   proportional   to  the  resistance  a  .r 


tin     single  sirai^ht    wire   in    the  diagram  the  lengths 
be   measiil'ed   atnl   substituted   tor  the  resistances  a  .r 

'     '     •        '  •  i\'e   eqliat  ion. 

rh  re-istance  coils  Lri\'inii  any  re<|uired  resistance 

way.  and  i.-  much  bet  ter  than  1  he  simple  st  might 

\\a.-  used   iii   the  illustration  sini)l      because 


The    Equal    Resistance    Method.     The   standard   cell    is   first    con- 

amjii  -n  'ii  id  er.  am  1  1  he  st  rengt  h 

•      '       is  noted.       I  hen   the  genei'at  <  >r  whose 

ii     •    ea   ured    is   subst  ii  uted   fur  i  he  standard 

the   mi  iliampere-   (  '-'    i-    noted.      The   electromotive 


DYNAMIC    ELECTRICITY 


107 


force  of  the  two  generate>rs  is  directly  proportional  to  the  currents 
in  niilliamperes;  and  F-  F'  ,/ 

A  slight  correction  mav  have  to  be' made  for  the  internal  resistances 
of  the  two  batteries,  but  this  is  not  necessary  if  the  external  resistance 
(in  the  resistance  box  and  galvanometer)  is  comparatively  large. 

Lumsden's  Method.  The  standard  cell  F/  and  the  generator 
FL>  whose1  electromotive  force  is  to  be  measured  are  placed  at  some 
distance  apart,  and  are  connected  with  each  other  so  as  to  torm  a  normal 
series.  The  zinc  of  the  first  is  connected  with  the1  copper  of  the  second, 
and  again  1  he  zinc  of  1  he  second  wit  h  t  he  copper  of  t  he  first .  A  (M'oss  line 
passes  from  t  lit1  middle  of  one  connecting  win1  to  t  he  middle  of  the  other, 
and  any  current  in  this  cross  wire  passes  through  a  galvanometer. 
One  of  the1  main  conducting  paths 
(Fig.  1(>2)  is  a  simple1  wire1  of  ample 
proportions  \vhose  resistance  is  so 
slight  that  it  eloes  not  have  to  be 
consielered.  Resistances  are  placed 
in  the1  other  conducting  path  be1- 
tween  the1  twe>  batteries.  One  of 
them,  R',  is  between  the  standard 
battery  and  the  point  where  the 
cross  wire1  leaves  the1  main  wire. 
This  has  a  fixed  standard  resistance 
so  large1  in  comparison  with  the1  in- 
ternal resistances  of  the  batteries 
that  the  latter  may  be1  disregarded. 

The1  ot  IKT  resistance1.  R-,  between  the  generator  whose1  electromotive  force 
is  to  be  measured  and  the1  attachment  of  the  cross  win1  is  obtained  from 
a  resistance1  box  by  means  of  which  any  requireel  resistance,  large1  or 
small,  may  be  eMiiploye'd.  The  resistance1  R-  is  varied  until  the  gal- 
vanometer, (I.  indicates  that  no  current  passes  through  the1  cross  wire 

A-B.     The1  electromotive  force1  of  the  generator  E-  is  the'ii  E-  ==  E'  ^  ,. 

The  d'Arsonval  Voltmeter.— The  voltmeter,  on  the'  principle  of  the' 
d'Arsonval  galvanometer,  is  made  in  different  sizes  and  shapes.  One  is 
like1  a  watch  and  has  two  terminals,  one  be-ing  a  point  which  may  be1 
pressed  upon  one  pole  of  the  battery  ami  the  other  an  insulated  wire 
leading  to  the  either  pede1  of  the  battery.  One'  of  this  size  and  shape  is 
very  convenient  for  use1  in  testing  voltaic  batteries.  Eae-h  different 
cell  may  be  tested  in  this  way  without  disconnecting  it  at  all  from  the 
rest  of  the  battery. 

In  some  batteries  there  is  a  switch-board  upon  which  are  metal 
contact-  which  lead  to  the  poles  of  the  different  cells,  and  it  is  simply 
nece-sary  to  touch  these  two  contae-ts  without  opening  the'  battery 
case  at  all. 

Still  other  batteries  are  more  elaborately  provided,  and  have1  double 
cell  -electors  by  which  the  two  poles  of  any  individual  cell,  as  well 
as  of  several  cells,  may  be  connected  wit  h  a  Mat  ionary  milliamperemeter. 
In  thi-  case'  the  cell  selector  is  applied  to  the  two  contacts  from  the 
same  cell:  the  terminal-  of  the  voltmeter  are  applied  to  the  terminal 
binding-posts/  of  the  switch-board  and  the1  current  is  turned  on.  Fach 


19S  MEDICAL    ELECTRICITY    AM)    RONTGEN    RAYS 

separate  cell  may  he  tested  in  this  way  or  any  nuinher  of  the  cells  at 
once. 

When  a  voltmeter  is  used  to  test  a  voltaic  cell  OH  open  circuit,  it 
means  that  the  current  is  not  allowed  to  pass  in  any  other  way.  The 
pules  of  the  cell  may  he  disconnected  from  anything  else,  or  if  con- 
ducting cords  are  attached  to  the  two  poles,  the  other  ends  of  the  cords 
d,>  not  coine  together  directly  or  through  any  other  conductor.  A 
battery  of  cells  may  be  tested  in  the  same  way.  The  circuit  is  open 
until  the  voltmeter  is  applied  to  the  positive  pole  of  the  cell  at  one  end 
of  the  series,  and  the  negative  pole  of  the  cell  at  the  other  end  of  the 
he  voltmeter  is  in  essence  a  galvanometer,  and  its  deflection 
up"ii  the  strength  of  the  current  passing  through  it.  As  the 
a  known  resistance,  the  electromotive  force  can  be  cal- 

.     It    is    customary,    however,    to    mark- 


h  indicate*  the  different  voltages,  and 
d  by  the  manufacturer  by  comparison 
e  absolute  standard  of  electromotive 
force  i-  obtained  from  a  standard  voltaic  cell  such  as  Clark's,  which  is 
l.l.'il  volts.  Another  method  of  graduating  a  voltmeter  is  by  using  a 
galvanometer  in  circuit  with  the  voltmeter.  The  resistance  of  both 
in-trumeiits  must  be  found  either  by  test  or  by  calculation  (the  resist- 
ance of  so  many  feet  of  copper  wire  of  such  a  size).  If  the  galvanometer 
shows  that  a  current  of  10  amperes  is  flowing  and  the  resistance  is  known 
to  be  1  1  ohms,  then  there  is  a  tension  of  110  volts,  and  the  place  on  the 
dial  of  the  voltmeter  to  which  the  needle  has  deviated  would  be  marked 
IK)  volts.  The  resistance  of  a  voltmeter  is  usually  a  very  large  one 
compared  with  that  of  the  normal  circuit,  so  that  the  current  is  often 
but  a  fraction  of  the  battery  current  when  in  actual  use.  Whether  this 
resistance  is  all  in  the  coils  of  the  voltmeter,  or  whether  it  is  partly 
in  a  -hunt,  depends  upon  the  magnitude  of  the  currents  it  is  designed 
to  measure. 

Voltmeters  about  as  large  as  a  watch  are  designed  to  measure  bat- 
teries  with  electromotive  forces  up  to  three  volts,  and  yielding  currents 
up  to  about  MO  amperes.  They  have  subdivisions  as  fine  as  I-  volt,  and 
are  -nil  able  tor  te-i  ing  t  he  electromotive  force  of  single1  cells  of  any  kind, 
especially  wel  or  dry  voltaic  cells  or  storage-battery  cells.  The  latter 
.-hould  be  recharged  before  they  have  become  entirely  exhausted.  To 
allow  them  in  remain  in  use  until  the  electromotive  force  falls  to  zero 
-erioii-|y  impair-  i  heir  elliciency. 

high  resistance  in  the  d'Arsonval  voltmeter,  a  great  many  times 
il  itself,  makes  it  give  suliicient  ly  accurate  results  without 
tor  taking  the  internal  resistance  of  the  cell  into  account 
ry  exceptional  cases,  where  extraordinary  exactness  is 

est   the  potential  of  a  storage  battery   in   operation 
t.      The  elect  romot  ive  force  mav  prove  to  be  about 
open  circuit  ,  and  .-till  may  fall  very  decidedly  when 
and   the  current    r-   parsing   through  the  motor  or 
indication   that    it    i-  high   time  that    the  cell  or 
d. 
g  the 


DYNAMIC    ELECTRICITY  100 

ing  currents  up  to  20  amperes,  are  about  4|  inches  in  diameter  and  pro- 
portionately thick  and  heavy.  They  look  just  like  amperemeters,  and 
have  binding-posts  to  which  wires  from  the  poles  of  the  generator  are  to 
be  securely  screwed. 

It  is  perfectly  practicable  in  any  case  to  measure  the  electromotive 
force  of  a  battery  while  in  actual  operation,  and  it  is  often  very  impor- 
tant to  do  so.  The  fact  that  the  voltmeter  has  a  very  high  relative  re- 
sistance makes  it  transmit  only  an  inconsiderable  fraction  of  the  current 
when  it  short  circuits  the  entire  apparatus  by  being  placed  directly  be- 
tween the  terminals  or  the  two  poles  of  the  battery.  It  is  not  in  series 
with  the  patient  or  apparatus  supplied  with  electric  current. 

The  needle  really  deviates  according  to  the  strength  of  the  current  or 
the  number  of  amperes  passing  through  the  uniform  resistance  of  the  large 
number  of  turns  of  wire  in  the  voltmeter,  and,  according  to  Ohm's  law, 
the  number  of  amperes  must  be  directly  proportional  to  the  number  of 
volts  when  the  resistance  is  uniform.  If  the  voltage  is  uniform,  as  in  the 
case1  of  the  110-volt  electric-lighting  current,  there  is  no  need  to  have 
a  voltmeter;  an  amperemeter  is  required  to  show  the  strength  of  the 
current,  and  indirectly  the  resistance  in  the  circuit.  If  the  voltage 
and  the  resistance  are  both  uniform  and  are  known,  neither  voltmeter 
nor  amperemeter  is  required;  the  current  strength  is  uniform,  and  can  be 
calculated  from  the  other  two  factors.  If  the  voltage  is  variable,  but 
the  resistance  uniform,  a  single  instrument,  the  regular  amperemeter, 
will  act  also  as  a  voltmeter.  Two  sets  of  figures  would  appear  upon 
the  dial,  the  outer  set  indicating  volts  and  the  inner  set  amperes.  Such 
a  meter  would  give  a  correct  reading  in  amperes  in  any  circuit,  but  its 
reading  in  volts  would  be  correct  only  in  a  circuit  having  exactly  the 
same  resistance  as  the  one  for  which  it  was  originally  tested  and  grad- 
uated. A  separate  voltmeter  having  in  itself  a  large  resistance  may  be 
placed  between  the  terminals  leading  to  any  circuit,  and  will  give  correct 
readings.  It  is  almost  indispensable  when  the  current  is  derived  from 
a  variable  source  of  electromotive  force,  and  when  the  resistance  in  the 
circuit  is  also  variable. 

Law's  Method  of  Condenser  Discharges. — The  amount  of  elec- 
tricity with  which  a  condenser  of  a  certain  capacity  can  be  charged 
varies  directly  with  the  electromotive  power.  Figure  163  shows  the  gen- 
eral arrangement  of  the  apparatus  for  making  this  test.  C  is  a  condenser 
of  a  capacity  of  -£  microfarad  (or  a  larger  one,  up  to  1  microfarad,  may 
be  used).  G  is  a  galvanometer  whose  resistance  is  G  ohms.  S  is  a 
shunt  past  the  galvanometer  provided  with  a  sliding  contact  by  means 
of  which  the  shunt  may  be  disconnected  entirety  or  it  may  offer  a 
resistance  varying  from  a  small  to  a  very  large  amount.  The  resistance 
in  the  shunt  is  S  ohms.  E  is  the  battery  and  K  the  key  by  which  the 
circuit  is  closed  or  opened.  Two  observations  are  required.  In  the 
first  a  smaller  battery  F/  (volts)  is  used,  and  the  galvanometer  is  not 
shunted.  On  pressing  the  key  the  condenser  quickly  becomes  charged, 
and  on  releasing  the  key  the  condenser  immediately  becomes  discharged. 
The  latter  effect  produces  a  momentary  current  and  a  readable  deflec- 
tion of  the  galvanometer.  In  the  second  observation  the  larger  battery 
E"  (volts)  is  used,  and  the  resistance  of  the  shunt  S  is  varied  until  the 
condenser  discharge  produces  the  same  deflection  of  the  galvanometer 
as  in  the  first  observation.  The  resistance  then  employed  in  the  shunt 

G  +  S " 
may  be  designated  as  S"  (ohms).     Then,  E  '  — —, —  • 


•JIM) 


MKDIC.VI.    KI.KCTKldTY    AM)    KONTCKN    HAYS 


It  the  weaker  t;vnerator  is  a  staiulard  cell  with  a  known  electromo- 
tive force,  a  nil  1  he  joint  resistance  in  t  he  galvanometer  and  its  shunt  is  so 
large  that  the  internal  resistances  of  either  battery  need  not  be  taken 
into  account,  thru  the  electromotive  force  of  the  stronger  battery  is 
equal  to  that  of  the  smaller  bat  tery  mult  iplied  by  the  multiplying  power 
ol  t  he  shunt  etiipi'  ivei  1. 

1:    the  electromotive  force  to  In1  tested  is  smaller  than  that   of  the 

lard   cell,    the   unknown   electromotive   force  would   be  tested   first 

M   -huntim:  the  galvanometer.      ,\nd  then  the  standard  cell  would 

U    -ubst  it  uted  and  so  shunted  as  to  produce  the  same  deflection.      The 

•;:.'. !;o\vn    electromotive    force   would    then    be   found  by    </i  n'dittt/ 

linber  ut   volts  produced  b\-  the  standard  cell   by  the  multiplying 

••  of  the  -hum  empli  >yed  wit  h  t  he  hit  ter. 

I:'  K  proves  necessary  or  desirable  to  use  a  shunt  with  each  of  the 
two  L:<  iterators,  thm  the  electromotive1  forces  of  the  two  generators  are 
directly  proportional  to  the  multiplying  powers  of  the  individual  shunts 
u-ed  wit  h  i  hem. 

The  diagram  Fig.  Kio*  shows  these  variable  shunts  only  in  a  sche- 
matic way.  In  reality  a  resistance  box  would  be  used  to  furnish  the 
wide  ratine  of  resistances  required  for  these  measurements. 

The  well-known  property  which  a  condenser  possesses  of  storing  up 
large  quantities  of  electricity  renders  it  possible  by  this  method  accu- 
rately to  measure  electromotive  forces  so  small  that  a  continuous  current 


•  hn  itigli  i  he  same  sensitive  galvanometer  would  not  produce  a  measure- 

leflectioi). 

I  hf  watt  i-  a  unit  of  electric  power  and  is  the  power  exerted  by  a 
current  of  !  ampere  with  a  pressure  of  1  volt.  A  \\  kilowatt  transformer 
l<  onojictuated  by  a  current  of  -1500  watts,  and  this  may  mean  100  volts 
:i:"l  ;•'  amp'-res;  or  any  numbers  the  product  of  which  will  be  4500. 

Hie  wattmeter  i-  de-igned  to  measure  the  power  consumed  in  any 

apparatus   through   \vhich  an  electric  current,  especially  an  alternating 

-  pa-sing.      In  the  case  ol'  a  direct   and  uninterrupted  current 

1    constant    voltage    and    amperau'e    passing    throuu'h    an 

"'.  '<""u"n  ;l'"l  ''onstani   resistance,  no  separate  wattmeter  is 

I  li"  inmiber  of  volts  multiplied   by  the  number  of  amperes 

'  '  "t   \vatts.      P.ut   with  an  alternatin»-  current  oi'  with  a 

'•h   is   interrupted,  as   by  a   \\'ehnelt   interrupter,   in 

"  i- difficult  to  say  diirin.ti:  just  what  part  of  each  period 

-  :t:"l  \voi'k  i-  bem-  perform,. d.  a  wattmeter  serves 

ti»  ni'-a-ure   1 1 

wattmeter   is   similar   to   that    of   the  elect  ro- 

dy tiamoini't er    p.   p. •:; 

i 


DYNAMIC    ELECTRICITY  201 

paths,  in  one  of  which  different  carefully  tested  resistances  are  intro- 
duced, and  in  the  other  is  introduced  the  resistance  which  is  to  be  meas- 
ured. The  word  bridge  has  reference  to  the  position  of  the  galvanometer 
in  relation  with  these  two  circuits.  The  galvanometer  is  inserted  in  a 
line  which  bridges  across  between  the  two  circuits,  and  a  current  flows 
through  it  from  the  circuit  in  which  there  is  the  greatest  tension.  We- 
might  use  the  face  of  a  clock  as  a  diagram  to  illustrate  the  principle  of 
the  Wheatstone  bridge.  Twelve  o'clock  would  indicate  the  point  at 
which  the  positive  wire  from  the  battery  is  connected  with  the  wire  cir- 
cuit, and  0  o'clock  the  connection  with  the  negative  wire.  The  current 
passes  between  these  points  along  two  different  paths:  down  along  the 
right-hand  margin  and  down  the  left-hand  margin  of  the  dial.  At  the 
center  of  the  clock  face  is  the  galvanometer,  whose  wires  pass  from 
the  3  to  the  9  o'clock  mark.  When  the  conditions  arc1  the  same  at  these1 
two  marks,  no  current  passes  through  the'  galvanometer,  but  when 
there1  is  a  stronger  current  in  consequence  of  a  greater  potential  at  3 
than  at  9,  the1  galvanometer  will  show  that  a  cm-rent  is  passing  through 
it  from  the  3  to  the1  9  o'clock  mark.  The  resistance  to  be  measured  is 
introduced  at  1  o'clock,  and  the  different  standard  resistances  are 
introduced  at  11  o'clock.  The  latter  resistances  are  increased  or 
diminished  until  they  are  equal  to  the  resistance  to  be  measured,  just 
as  standard  weights  are  used  to  weigh  an  object.  Equality  between 
the  two  resistances  is  indicated  when  no  current  passes  through  the1 
galvanometer. 

REGULATION  OF  ELECTRIC  CURRENTS 

Rheostat. — The1  regulation  of  the1  current  from  a  voltaic  battery  for 
therapeutic  application  may  of  tern  be  accomplished  by  selecting  the1 
proper  number  and  arrange'ine>nt  of  cells  employed,  but  a  rheostat  or 
adjustable  resistance  is  an  invaluable  addition.  It  is  often  necessary 
to  use  heavy  currents  which  are  free  from  any  discomfort  when  turne'd 
on  and  off  very  gradually,  but  which  produce1  disagreeable  shocks  if 
suddenly  increased  or  diminished.  A  suitable  rheostat  enables  one  to 
change  the1  strength  of  the  current  more1  gradually  than  any  cell  selector. 
The  employment  of  the1  poweTi'ul  and  sometimes  even  dangerous  current 
from  a  dynamo  ivquhv-s  the  use  of  a  rheostat  or  of  a  volt  controller  to 
reduce  t  lie  amperage  or  the  voltage'  of  the  current  before  it  can  be  applied 
to  the  human  body  at  all.  Her0  the'  rheostat  is  used  not  only  to  turn 
the  current  on  and  off  gradually,  but  also  to  limit  the  amount  which 
can  reach  the  patient.  There  is  no  convenient  me>ans  of  regulating 
the  power  of  the  dynamo  to  the  requirements  of  e'ach  therapeutic 
application,  and  so  different  instruments  are  employed  to  modify  the 
current  before1  it  reaches  the  patient. 

The  pri-nc i]>le  nf  the  r}n  o*t<it  is  exceedingly  simple.  The  wire  leading 
to  the  patient  is  cut.  and  between  the  two  cut  ends  is  fastened  a  variable1 
resistance.  This  may  consist  of  a  ve'ssel  of  water  into  which  dip  two 
we'dge'-shaped  pieces  of  carbon  or  some  other  conductor.  The  carbons 
are  connected  with  the  two  cut  ends  of  the  wire1,  and  the  current  encoun- 
ters a  greater  resistance  when  they  dip  slightly  into  the  liquid,  and  a 
smaller  resistance  when  the  surface  ot  contact  is  increased  by  dipping 
the  triangular  carbons  dee])  into  the  liquid.  Other  rheostats  consist  ot 
strips  of  graphite1  inlaid  in  hard  rubber,  a  sliding  contact  determining 
the  length  of  graphite  through  which  the  current  must  pass.  Others 
are  made1  of  coils  of  wire  or  metal  ribbons  of  a  material  like1  iron  or 


202  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

(ierman  s''ver,  long  and  thin  enough  to  present  the  requisite  amount 
of  resistance.  The  length  of  resisting  medium  through  which  the  current 
mu^t  pass  is  regulated  by  means  of  a  sliding  contact.  Still  another 
rheostat  depends  upon  the  fact  that  a  change  in  the  conductivity  of 
carbon  takes  place  under  varying  degrees  of  pressure.  Turning  a 
thumb-screw  in  one  direction  or  the  other  increases  or  diminishes  the 
resistance. 

The  lii/uiil,  the  carbon  compression,  and  the  graphite  rheostats  are 
seldom  used  except  for  lighter  electrotherapeutic  currents,  and  the 
wire  and  the  ribbon  rheostats  are  necessary  for  the  heavier  currents 
required  to  operate  motors  and  x-ray  coils.  A  simple  and  effective 
rheostat  is  formed  by  one  or  more  incandescent  electric  lamps  arranged 
MI  that  the  lamp  and  the  electrotherapeutic  apparatus  form  a 
itinuous  circuit.  No  matter  how  little  resistance  there  may 
rest  of  the  circuit,  a  16-calidle-power  lamp  limits  the  strength 
of  the  current  to  about  .',  ampere. 

A  rheostat  may  consist  of  one  or  more  incandescent  electric  lamps 
arranged  in  series,  so  that  t  he  lamps  and  the  electrotherapeutic  apparatus 
form  a  single  continuous  circuit.  A  series  of  lamps  will  limit  the 
current  to  anv  small  fraction  of  an  ampere  that  may  be  desired,  while 
a  number  of  lamps  arranged  in  parallel  will  permit  the  passage  of  as 
il  re  at  a  number  of  amperes  as  may  be  desired,  for  instance,  for  charging 
a  s1 '  i  rage  bat  tery. 

The  amount  of  current  which  will  pass  through  a  series  of  resistances 
is  equal  to  the  electromotive  force  divided  by  the  sum  of  all  the  resist- 
ances. \\  hen,  however,  these  resistances  are  arranged  so  as  to  form 
parallel  paths  for  the  current,  the  conditions  are  practically  reversed. 
The  amount  of  current  which  will  pass  is  equal  to  the  sum  of  the  currents 
which  the  different  paths  would  transmit  separately;  so  that  in  the  case 
of  the  110- volt  electric-lighting  current  which  is  supplied  by  a  constant 
potential  dynamo,  a  series  of  20  16-candle-power  lamps  will  transmit 
a  current  of  about  4\t  ampere;  while  the  same  20  lamps  arranged  in 
parallel  would  transmit  about  10  amperes. 

\  i  r>i  i/nnl  rcxixtances  trliich  are  easily  varied  may  be  obtained  by 
drawing  several  parallel  lines  with  India  ink  upon  strong  drawing  paper. 
The-e  are  close  together,  but  of  decreasing  length.  A  metal  clamp 
' o uc lie-  all  1  he  line-  at  one  end,  and  a  metal  contact  may  touch  from  one 
i"  all  "I  these  line-  according  to  where  it  is  applied.  Resistances  varying 
from  n.nl  to  20.000.  meg-ohms  are  obtained  in  this  way.  The  current 
transmitted  varies  from  0.1  ma.  downward.1 

I  he  volt  controller  or  reducer  of  potential  depends  on  an  entirely 


ga  uniform  resistance  throughout , 
along  t  he  line.       1  f  t  lie  dii'fer- 
is  a  cert  am  i'ract  ion  oi  t  he 
inc.  the  difference  in  pre 


DYNAMIC    ELECTRICITY 


203 


connected  with  one  polo  of  the  dynamo  and  a  point  half-way  along  the 
external  resistance  would  register  a  tension  of  55  volts.  An  apparatus 
connected  with  these  two  points  would  receive  a  current  the  strength  of 
which  would  be  found  by  dividing  55  volts  by  the  resistance  of  the 
apparatus  in  accordance  with  Ohm's  law.  The  same  55  volts  potential 
can  l>e  obtained  by  making  the  connection  with  two  points  anywhere 
along  the  main  line,  providing  that  half  the  resistance  in  the  main  line; 
is  included  between  these  two  points.  Any  fraction  of  the  original 
110  volts  may  be  obtained  by  connecting  the  apparatus  at  points  along 
the  main  line  which  include  between  them  the  required  fraction  of  the 
resistance  in  the  main  line.  The  volt  controller  is  an  apparatus  for 
regulating  the  voltage  supplied  to  a  medical  apparatus  by  connecting 
it  with  points  along  the  main  line  between  which  a  variable  portion  of 
the  resistance  in  the  main  line  may  be  included.  The  resistance  in  the 
main  line  consists  chiefly  of  a  resistance  coil  in  the  volt  controller  itself 
and  the  contacts  are  made  by  moving  a  contact  spring  along  over  the 
different  turns  of  wire.  If  both  terminals  of  the  medical  apparatus  are 
in  contact  with  the  same  turn  of  wire  in  the  volt  controller,  there  will 
be  no  difference  in  potential,  the  voltage  in  the  therapeutic  apparatus 
will  be  zero,  and  no  current  will  How  through  it.  Moving  the  contact 
to  different  points  so  as  to  embrace  more  and  more  of  the  resistance 


in  the  main  line,  the  potential  supplied  1o  the  medical  apparatus  may 
be  varied  from  1  up  to  1  10  volts  (Fig.  lti-1 1. 

A  shunt  circuit  has  many  important  applications  in  electrothera- 
peutics besides  that  of  a  volt  controller.  It  is  a  conducting  circuit 
joining  t  wo  points  in  a  conductor  t  hrougli  which  a  portion  of  t lie  current 
inav  pass.  The  intensity  or  amperage  of  the  current  through  the  two 
conducting  paths  is  in  inverse  proportion  to  the  resistances  in  the  two. 
It  one  has  a  hundred  times  the  resistance  ot  the  other,  only  one  oiie- 
hundredth  part  as  much  current  will  puss  through  it  as  through  the 
other  parallel  path,  with  less  resistance.  The  tension  or  voltage  at  the 


201  MKDICA1.    KI.KCTHIC1TY    AND    ROXTGEN    KAYS 

two  points  of  junction  i-  the  same  for  both  circuits,  and  the  strength 
of  the  current  in  each  is  absolutely  regulated  by  the  resistance. 

Another  important  application  of  the  shunt  is  in  connection  with 
the  Lialvanometer  or  amperemeter.  The  heavy  currents  used  for  .r-ray 
coils  would  quickly  heat  up  and  destroy  the  fine  wire  in  a  galvanometer, 
and,  lie-ides  the  injury  to  the  meter,  its  resistance  would  occasion  a 
irreat  waste  of  power.  And  then,  again,  the  directive1  influence  of  such 
a  powerful  current  passing  through  the  many  turns  of  an  amperemeter 
would  be  entirely  too  great  for  practical  purposes.  The  maximum 
deviation  would  be  produced  by  the  weakest  current  ever  employed 
for  Mich  purposes,  and  one  could  not  read  on  the  meter  the  different 
additional  strengths  of  current.  In  fact,  an  instrument  of  this  kind 
is  .-o  delicate  in  construction  and  so  sensitive  to  the  directive  influence 
of  the  current  that  it  is  fitted  to  transmit  milliamperes  or  thousandths 
of  an  ampere  rather  than  whole  amperes.  To  fit  it  for  the  measure- 
ment of  currents  varying  from  1  to  50  amperes,  the  amperemeter  is 
placed  in  shunt.  A  metal  strip  passes  directly  from  one  binding-post 
of  the  amperemeter  to  the  other,  and  a  very  large  portion  of  the  current 
passes  through  this,  while  a  very  small  portion  passes  through  the 
winding  of  the  amperemeter.  The  exact  fractions  of  the  current  passing 
by  these  two  different  paths  between  the  positive  and  negative  binding- 
posts  are  determined  by  the  very  small  amount  of  resistance  in  the 
metal  strip  and  the  very  large  amount  of  resistance  in  the  many  turns 
of  tine  wire  in  the  winding  of  the  galvanometer. 

Another  type  of  amperemeter  for  heavy  currents  has  only  a   very 
few  turns,  or  possibly  a  single  turn,  or  even  a  straight  bar  in  relation 
\\  it  h  a  movable  magnetic  needle.      It  is  for  currents  of  such  great  amper- 
age that   it   is  not   necessary  to  multiply  their  directive  influence,  as  in 
the    ordinary    galvanometer.     These    are    not,    however,    the    currents 
,  i\vd  in  elect  ro therapeutics,  but  t  hose  employed  in  the  t  ransnnssii  >n 
•  iwer,  hundreds  or  even  thousands  of  horse-power. 

ti//<l  iiin/n  rin/i    of  electricity  from  different   sources,  and 
•nt    purposes,   differs   very   widely.      A   single   voltaic 
nnotive   force  of  about    1  ',    volts,   differing  somewhat 
ect  I'odes  and  elect  rolyte  employed  in  us  const  rue  t  ion. 
•nt    from   a  single  voltaic  cell   varies  from   a 
ut    .'IM  amperes  on    short-circuit    to  a    minimum  when 
in  the  external  circuit.      A  battery  or  any 
•nt    is  -mil   to  he  short -circuited  when   the 
'•'   lengl  h  of  a  u'ood  conduct  or;  in  ol  her 
has  practically  no  resistance.      I'nder 
amperes  of  current   will  be  found  to 
laracter  <  if  i  he  cell.      The<  nvt  ically. 
ivy  dividing  the  elect  roim  it  ive 
n   ohms.      The   result    will   be 
•  ol)  ampere-.  acc< irding  to  t  he 
in  <  irdinary  use.     The  larger 

I  he  elect  r<  ilvte,   1  he  less  1  he 
e  Lrreal  er  the  current   st  rengt  h. 
ic  cell   i-  a  ]  i]  iliei  I  to  the  human 
•rtial    resistance  becomes  about    1  OHO 
inti  nial  resistance  t  hat   it 
'i'    m    the   calculation    of   the   current 


DYNAMIC    ELECTRICITY  205 

strength.  The  current  strength  will  be  about  1.5  milliamperes  (}\  volts 
divided  by  about  1000  ohms),  and  it  will  not  vary  appreciably  with 
the  size  of  the  voltaic  cells.  It  would  vary,  of  course,  with  different 
types  of  cell  with  different  electromotive  forces.  A  current  of  this 
voltage  and  amperage  can  hardly  be  detected  when  applied  to  the 
unbroken  skin  of  the  hand;  but  when  applied  to  more  sensitive  parts, 
such  as  the  teeth,  it  is  readily  perceived,  and  any  stronger  current  is 
painful.  Such  a  current  produces  scarcely  a  visible  spark  when  the 
contact  is  made  or  broken.  It  may  produce  electrolysis  or  chemic 
decomposition  in  a  solution  through  which  it  passes.  The  same  voltage 
applied  to  a  small  electric  lamp,  like1  that  of  a  cystoscope,  will  slightly 
heat  its  filament,  and  here  the  size  of  the  voltaic  cell  will  have  a  great 
influence  upon  the  strength  of  the  current  and  its  heating  and  luminous 
effect.  The  same  remarks  apply  to  the  effect  of  a  single  voltaic  cell 
in  heating  a  cautery  point. 

For  the  majority  of  direct  elcctrotherapeutic  applications  an  amperage 
of  from  10  to  15  milliamperes  of  current  is  required,  and  with  the  ordi- 
nary resistance  of  the  body  this  implies  a  tension  of  10  or  15  volts.  To 
obtain  such  a  current  from  voltaic  cells,  several  of  them — about  10 — 
must  be  set  up  in  series,  so  as  to  secure  their  combined  electromotive 
force.  The  current  strength  or  amperage  is  approximately  multiplied 
by  the  number  of  cells:  for  though  their  internal  resistance  is  also 
multiplied,  the  latter  resistance  is  very  small  as  compared  with  the 
resistance  of  the  human  body.  A  current  of  this  strength  produces  a 
sensation  and  other  physiologic  effects  wherever  applied.  It  will 
produce,  however,  only  a  very  small  spark  on  making  or  breaking  the 
circuit,  and  for  application  to  the  human  body  large  or  small  cells  will 
produce  an  equal  current.  The  same  10  cells  with  their  15  volts  poten- 
tial will  produce  excellent  lighting  and  heating  effects:  in  fact,  this 
voltage  is  more  than  sufficient  for  endoscopic  lamps  and  cautery  points. 
For  cautery  purposes  especially,  the  cells  should  be  large1,  as  from  10  to 
20  amperes  of  current  arc  usually  required.  Or  the  series  may  consist 
of  a  number  of  parallel  sets  of  smaller  cells. 

The  heavier  currents  for  .r-ray  work  may  also  be  obtained  from  a  voltaic 
battery  or  from  a  storage1  battery.  In  cither  case1  the  cells  are  arranged 
in  series  to  produce  a  potential  of  1(1  or  12  volts,  and  the  cells  should 
either  be  large  enough  to  yield  about  10  amperes,  or  else  two  or  more1 
in  "parallel  will  have  to  take  the  place  of  each  one  in  the  series. 

Arc-lamp*  and  electric  motor*  may  be  run  by  currents  from  a  voltaic 
battery.  The  lamp  requires  50  to  100  volts  and  5  to  50  amperes. 
Both  this  and  the  electric  motor  are  much  more  economically  and 
conveniently  run  by  a  current  from  a  dynamo  than  from  a  voltaic 
battery. 

The  110-volt  direct  current  from  a  dynamo  gives  one  a  disagreeable 
shock  when  any  part  of  the  body  is  introduced  into  the  circuit,  for 
instance,  by  touching  the  fingers  to  two  l>are  hind-posts  to  see  whether 
there  is  any  current.  It  will  arc  across  a  considerable  fraction  of  an 
inch  at  the  break,  and  if  it  is  turned  on  and  off  by  a  kev.  this  should 
have  a  spring  producing  a  quick  break.  This  is  to  prevent  the  for- 
mation of  an  arc,  which  would  occur  if  the  two  contact  surfaces  were 
slowly  separated.  An  arc  would  melt  and  ruin  the  contact  surface.-. 
The  110-volt  direct  current  will  not  spontaneously  leap  across  a  space 
nf  even  an  eighth  of  an  inch,  and  anv  siood  insulation,  such  as  a  laver 


201)  MKDIfAI.    KLECTRK'ITY    AND    KONTCKN    RAYS 

of  nutta-percha  an  eighth  of  an  inch  thick,  covered  by  a  braided  fabric 
of  silk  or  cotton,  will  prevent  the  current  from  escaping  from  one  win' 
to  tin1  other,  even  if  the  covered  wires  are  twisted  together.  This  is 
often  done  for  convenience,  so  as  to  be  handled  like  a  single  cord,  and 
even  >inirle  cords  of  gutta-percha  about  half  an  inch  in  diameter  are 
made,  iiu'lo-nm-  both  wires.  The  fact  that  such  an  insulation  must 
eventually  become  cracked  and  porous  in  spots  does  not  mean  that  the 
current  will  neces-arily  leap  across  at  such  a  point.  Kven  a  porous 
covering  will  >uilice  as  lonsj;  as  the  two  wires  are  held  at  an  appreciable 
distance  from  each  other,  and  no  good  conductor  extends  from  one  to 
the  other.  Thi-  current  may  be  short-circuited  by  cutting  a  charged 
double  conducting  cord  with  a  penknife.  Both  insulating  layers  are 
cut  through,  and  the  steel  coming  in  contact  with  both  wires  allows  the 
full  force  of  the  current  to  pass  through  the  very  small  resistance  of  the 
knife-blade.  The  result  is  startling,  and  may  be  disastrous.  An 
excessively  .-iron ii  current  passes  across  this  small  space,  and  tremen- 
d  ms  heal  is  gem-rated,  burning  a  piece  out  of  the  knife-blade,  not 
meivh  fusing,  but  vapormng.  the  steel.  The  wires  at  this  point  are 
destroyed  in  the  same  way.  and  the  safely  fuses  all  along  the  line  are 
burned  out.  Tin.-  brings  t  he  flo\\-  of  electricity  to  an  end.  and  saves  1  he 
ho  ise  from  beii in  set  on  tire.  The  wires  throughout  the  house  would  gel  so 
'in  the  passage  of  a  short-circuited  1 10- volt  current  that  in  a  few 
minutes  thev  would  set  lire  to  i  he  woodwork.  'I  he  same  undesirable 
experiment  may  be  made  by  holding  a  knife  or  a  key  against  anv  exposed 
parts  of  the  two  wires,  or  the  metal  parts  of  a  motor,  or  a  switch,  or  the 
terminals  oi  a  coil.  '1  he  same  thing  mav  happen  from  one  of  t  he  wires 
becoming  loosened  in  some  way.  and  its  bare  end  coming  in  contact 
with  the  hare  end  of  the  other  wire,  or  with  some  metallic  part  of  the 
apparatu.-  connected  wiih  the  other  wire.  About  almost  every  electric 
apparatus  to  be  run  by  the  1  MJ-volt  current  there  are  portions  exposed 
tin  possibility  of  short-circuit.  Such  portions,  switches  especially. 
ie  separated  from  any  inflammable  structure  by  a  marble  or 
slate  base.  I  )o  not  bring  any  metallic  object  near  any  exposed  part 
'•'•'•  u'ire  or  apparatu-.  and  in  making  the  necessary  adjustment  of 
itches  niid  rheostats  touch  only  the  insulated  handle  provided  for 
that  purpo-e. 

In  >he  case  of  a  dynamo,  the  electromotive  force  is  usually  so  great 
in  proportion  to  the  internal  resistance  that  very  often  the  only  electro- 
motive force  to  lie  considered  i.-  the  voltage  at  the  two  terminals  of  the 
dynamo,  and  t  he  only  resistance  to  be  considered  is  that  in  the  external 
circuit . 

\  '•  .  :  this  voltage  will  pass  across  a  considerable  space  if  the 

and  there  i-  so  little  resistance  in  the  circuit   as 

1    ,     laruv  number  of  amperes,  and  the  contact    is 

i-ij.       I  In-    i-    the    pvin  ipon    \vhich    an    electric    arc    is 

.  .       1.      The   -ame   voltage   is    ;."'    ;ipi    to   cross  even   a   small   space 

•  •    'hi    '•••:.••:•••   i-  •  iade,  and  a  ver\   -buhl   impi  'ft'ect  ion  in  i  he  con  t  act 

•ii  r rent    from  pa  — mil.       I'here  a  re  t  wo  reasons.  1  here- 

\vire-  soldered   together  at    every   permanent   joint 

V     ii mpleie   connection    mi^ht    either   prevent 

•_•  •>:•  i  he  \viivs  mi<  luring  t  he  ll<  >w  of 

ilnim  an-  -et   fire  to  rk  or  iras. 

i     isinii  t  In    I  HI-VI  ill    diced  current  should 


DYNAMIC    ELECTRICITY  207 

comply  with  the  regulations  of  the  U.  S.  National  Board  of  Fire  Under- 
writers in  order  to  be  safe  from  risk  of  fire,  and  it  then  does  not  add 
anything  to  the  cost  of  fire  insurance.  In  many  places  it  is  a  criminal 
offense  to  turn  on  the  current  at  all  until  the  wiring  has  been  inspected 
and  found  to  comply  with  these  regulations.  A  pair  of  Xo.  14  copper 
wires  are  suitable  for  one  to  eight  incandescent  lamps.  An  .r-ray 
apparatus  should  always  have  its  own  pair  of  wires  leading  from  the 
mains,  and  not  tapped  for  lamps  or  any  other  apparatus.  They  should 
he  a  pair  of  Xo.  10  wires.  This  is  also  the  proper  size1  for  the  powerful 
arc-lights  employed  for  phototherapy. 

Electric-light  and  Power  Service. — The  commercial  arrangement 
for  generating  direct  current  for  electric-light  and  power  service  in 
cities  is  usually  as  follows:  Two  1  10-volt  dynamos  are  connected  in 
series;  this  gives  a  three-wire  distribution  service.  The  middle  wire 
is  called  the  neutral  one.  If  the  house  is  to  be  supplied  with  110  volts, 
then  the  three  wires  are  brought  into  the  basement  and  connected  with 
the  meter.  In  order  to  obtain  a  110- volt  current,  connections  are  made 
with  the  neutral  and  one  outside  wire.  If  a  220-volt  current  is  desired, 
then  connections  are  made  with  two  outside  wires.  The  size  of  the 
distributing  wires  is  regulated  by  the  rule  of  the  Fire  Underwriters. 

In  having  a  place  wired,  it  is  always  well  to  have  the  contractor 
use  a  size  or  two  larger  than  the  Fire  Underwriters'  rules  call  for,  so 
that  in  case  more1  current  is  desired,  it  can  be  safely  taken  from  the 
original  installation.  The  extra  cost  does  not  amount  to  much. 

In  having  electric  service  put  in,  it  is  always  well  to  see  that  the 
cut-out  blocks  and  fuses  are  put  in  a  convenient  place,  so  that  in  case 
of  an  accident  a  fuse  can  be  easily  replaced.  As  a  rule,  contractors  do 
not  figure  on  putting  in  a  main  switch,  but  it  is  advisable  to  have  this 
done,  and  also  to  have1  it.  placed  in  circuit  before  the  current  enters  the 
meter.  The  particular  advantage  of  this  is  that  in  case  you  go  away 
for  any  length  of  time,  the  current  is  absolutely  shut  off  from  the  meter 
and  the  rest  of  the  house.  As  long  as  the  meter  is  connected  with  the 
service,  it  is  consuming  a  small  amount  of  current :  this  usually  amounts 
to  about  30  to  -40  cents  a  month.  Another  advantage  of  the  switch  is 
that  if  you  wish  to  make  any  changes,  you  can  open  this  main  line 
switch,  being  absolutely  certain  of  not  being  injured  by  an  accidental 
short -circuit. 

A  "flush  receptacle"  should  be  used  for  a  Cooper  Hewitt  lam])  or 
for  a  negative  examining  box  with  several  incandescent  lamps.  A 
fused  knife  switch  on  a  slate  base  is  the  proper  tiling  for  the  .r-ray 
connection  or  for  a  large  arc-lamp.  The  ordinal'}'  key  receptacle  tor 
a  single  incandescent  lamp  may  be  used  for  small  motors  and  for  cabinets 
for  voltaic  and  faradic  treatment,  for  diagnostic  illumination,  and 
for  cauterv. 


•JOS  MKDICAL    KLKCTIUCITY    AND    UOXTCiKX    HAYS 


(  >i   i  -ii>i:    \\  <  U;K. 

Sf[-\  ice  \\  ire-  inii-i  !i:!\  i-  :ni  M|  i|>n>\'c(l  nil  'her  insulating  covering.      Line  wires 
..r\;c.'-.    i!.;-.:    li:i\.    an  approved   \\ ea 1 1  uT-j in >< >f    or    rubber  insulating 
L:        Ml   tit-  \\iiv-  ruii>l    have  :m   in-ulation  equal   to   ihat    of  the  conductors 
•  •  •  \ 

\1  ,~-  lie  -ii  placed  thai  moist  un-  cannot  form  a  cross  connection  between 
•I  ,-in.  iini  h  foot  apart,  and  not  in  contact  with  any  substance  other  than 

their     •  linu       .:       >rt>       \Yood'-n    Mock-  to   whicli   insulator-  are  attached   must 

: .    ;     vi  r  1 1  i  ii  i 'in  ire  -urtace  \\  it  h  at  least  t  wo  coats  ot  waterproof  paint. 
MM-'    lie   -o   -plicrd   or  joined   as   to   be   both   mechanically   and   electrically 
mil    -older      The  joints  must    then  be  soldered,  to  insure  preservation, 
covered  wit  Ii  an  in-ulat  ion  equal  to  t  hat  on  t  he  conductors. 

All  joint-  mu-t  be  -oldered.  even  if  made  with  some  form  of  patent  splicing 
device.  Thi-  ruling  applie-  to  joints  and  splices  in  all  classes  of  wirini:  covered  by 

these   rule- 

I\>II>F.    VYoHK. 
\Vires 

Mu-;  not  be  of  smaller  si/e  than  Xo.  14  H.  A:  S.  guagc,  except  as  allowed 
under  No>.  _'  t  v  and  \~>  b. 

Tie  \\iiv-  mu-t  have  an  insulation  equal  to  that  of  the  conductors  they 
confine. 

Mu-t  be  so  -pliced  or  joined  as  to  be  both  mechanically  and  electrically 
secure  without  -older.  The  joints  must  then  be  soldi-red  to  insure  preservation 
and  covered  wit  h  an  in-ulat  ion  equal  to  t  hat  on  the  conductors. 

Stranded  wire.-  mu-t  be  soldered  before  being  fastened  under  clamps  or  binding 
-crews,  and  whether  stranded  or  .-olid,  when  they  have  a  conductivity  greater 
than  that  of  \o.  ,s  11  A.  S.  guage.  they  mu.-t  be  soldered  into  lugs  for  all  terminal  con- 

Ileet  ;,  ills. 

</  Mu-t  be  separated  from  contact  witli  walls,  floors,  timbers,  or  partitions, 
through  which  they  may  pa—  by  non-combustible,  non-absorptive,  insulating 
tube-,  -iicli  a-  !_rla--  oi1  porce'-tin.  except  as  provided  in  Xo.  L'4.  u. 

Mu-t    be  kept    free  from   contact    with  gas,   water,  or  other  metallic  piping, 

or  any   other  conductor-  or  conducting   material   which   they   may   cro-s,    by   some 

lou-   and    firmly    fixed   non-conductor,   creating  a   separation   of  at    least    one 

I  )e  vial  ion-  from  t  his  rule  may  sometimes  be  allowed  by  special  permission. 

\\hen  one   wire  cro-.-es  another  wire,   the  best   and  usual  means  of  separating 

them  i-  by  mi-ail-  of  a  pi  irc«'lain  t  ube  on  one  of  t  hem.     The  t  u  be  should  be  prevented 

•._'  ii  it    of    place,  either  by  a   cleat   at    each  end  or  by  taping    it    securely 

I  he  -atne  m<  ihod  may  be  adopted  where  wires  pa-s  close  to  iron  pipe.-,  beams, 

i-re  tin        ire-   arv   above   the   pipe-,   as   i-  generally   the   case,   ample   pro- 

i"ti   can  \    be   -eeiired   by   -upporting  the   \\ires   with   a   jiorcelain   cleat 

:  I         '  e    the    pipe    a-    po—ibie. 

MM-'    bi        i  |     iced   in   \\i't    place-   liial    an  air-.-pace  will  be  left   IxMween  con- 
IILT.  and  the  lorim-r  mu-t   be  run  in  such  a  way  that   they 
•  ti'act    \\   ih    the    pipe    accidentally,      \\ires   should    be   run    over. 

ipon  which  moj-t  ure  i-  likely  to  gather  or  which,  by  leak- 
.  •  n  a  circuit . 


DYNAMIC    ELECTRICITY  200 

Ixsn,. \TION  rot;  VOLT ACKS  HKTWKF.N  0  AND  <>()(). 

(/>)   Must    lie  ot    rubber  or  other  approved  substance,   mid   of  a   thickness   not 
less  than  that  given  in  the  following  table: 

P>.  it  S.  (lauge  Thir-kness. 

IS  to  Hi .',  inch. 

lf>  to  S      >r   •' 

7  to  •_> ;v,  •• 

1  to  ()()()() 


Measurements  of  insulatinir  wall  are  to  lie  made  at  the  thinnest  portion  of  the 
dielectric. 

!r)  The  completed  covering  must  show  an  insulation  resistance  of  at  least 
100  megohms  per  mile  during  thirty  days'  immersion  in  water  at  70°  I-'.1 

('/>  Kach  foot  of  the  completed  covering  must  show  a  dielectric  strength  suffi- 
cient to  resist,  throughout  live  minutes,  the  application  of  an  electromotive  force 
of  .':!()( )0  volts  p(>r  i;'f  inch  thickness  of  insulation  under  the  following  conditions: 

The  source  of  alternating  electromotive  force  shall  be  a  transformer  of  at  least 
one  kilowatt  capacity.  The  application  of  the  electromotive  force  shall  first  be 
made  at  1000  volts  for  five  minutes,  and  then  the  voltage  increased  by  steps  of  not 
over  .'JOOO  volts,  each  held  for  five  minutes,  until  the  rupture  of  the  insulation  occurs. 
The  tests  for  dielectric  strength  shall  be  made  on  a  sample  of  wire  which  has  been 
immersed  in  water  for  seventy-two  hours.  One  foot  of  the  wire  >mder  test  is  to  be 
submerged  in  a  conducting  liquid  in  a  metal  trough,  one  of  the  transformer  ter- 
minals being  connected  to  the  copper  of  the  wire  and  the  other  to  the  metal  of  the 
trough. 

PROTECTING  BKAID. 

(Jt)  All  the  above  insulations  must  be  protected  by  a  substantial  braided  cover- 
ing, properly  saturated  with  a  preservative  compound.  This  covering  must  be 
sufficiently  strong  to  withstand  all  the  abrasion  likely  to  be  met  with  in  practice, 
and  sufficiently  elastic  to  permit  all  wires  smaller  than  Xo.  7  I>.  iV  S.  gage  to  be  bent 
around  a  cylinder  with  twice  the  diameter  of  the  wire,  without  injury  to  the  braid. 

Fusing-points  of  Metals  and  Alloys. — (rennan  xilrcr,  used  for 
rheostats,  melts  at  about  HHK>°  F. 

/<'//.SY-  irircx  to  melt  when  heated  by  a  current  in  excess  of  the  one 
they  are  designed  to  carry  are  made  of  different  alloys. 

l-'u^lhlt'  (it///il(/<i in  melts  at  ">.'>°  (\,  or  about  l'J7°  F.  It  consists  of 
mercury,  1  part,  and  Aivet's  metal,  0  parts. 

}\'D<>(/'S  /illoi/  melts  at  ()S°  ('.,  or  1  .">4  °  F.,  and  consists  of  lead.  '2 
parts;  tin,  4  parts;  bismuth,  7  or  S  parts:  and  cadmium,  1  or  '2  parts. 

Atrct'x  n/rtdl  melts  at  !U°  ('.,  or  L'01  °  F..  and  consists  of  lead.  5  parts: 
tin.  .'!  pails:  bismuth,  s  parts. 

An  (tllo'i  nir/li-ni/  a/  11!)°  ('..  or  iMd0  F..  consists  of  tin.  4  parts: 
bismuth.  •">  parts:  lead.  1  part. 

A-n  ul/ni/  in<//h/f/  (it  141°  ('..  or  '2S(>°  F.,  consists  of  tin.  1  part:  bis- 
muth. 1  part. 

1  The  insulation  resistance  of  a  gutta-percha  covered  wire  is  tested  by  immersing 
a  mile  or  some  fraction  of  a  mile  of  the  insulated  wire,  except  at  its  two  ends,  in 
acidulated  water.  The  tank  must  be  of  highly  insulating  material.  ( )ne  pole  of  a 
battery  with  known  electromotive  force  is  attached  to  a  metal  plate  which  dips 
into  the  liquid.  The  other  pole  is  attached  to  a  galvanometer  or  an  electrometer 
from  which  a  connection  is  made  with  one  end  of  the  wire  to  be  tested.  The  other 
mid  of  the  wire  is  outside  of  flic  conducting  liquid,  and  is  not  in  contact  with  any 
conductor.  The  strength  of  current  indicated  by  the  meter  furnishes  a  measure 
of  the  insulation  resistance,  the  greater  the  resistance,  the  weaker  the  current  will  be. 
14 


210  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

An  <///«//  imltimj  at  H>.~>°  ('..  or  334°  F.,  consists  of  tin,  2  parts; 
bismuth.  1  part;  or  tin.  3  parts;  lead.  2  ])arts. 

All  these  fu-il>le  alloys  are  remarkable  from  the  fact  that  they  melt 
at  a  mudi  lower  temperature  than  any  of  the  separate  ingredients. 
The  meltim:-poim  of  tin  is  -1-1 2 c  F.:that  of  bismuth  is  4<)7°  F..  and  of 
lead,  til  2  F. 

The  melting-points  ()f  other  metals  and  alloys  used  in  electric 
instruments  are:  Zinc.  773:  F.;  brass,  1X(><)°  F'.;  silver.  1N7-T  F.; 
copper.  H»~>4-  F.:  iron  (wrought  iron  or  iron  wire).  32S6°F.;  nickel, 
2^1)0  ;  F.;  platinum.  :V_N(i:  F. 

Solder  consists  of  various  alloys,  the  common  tin-solder  containing 
tin  an«l  lead  in  proportions  ,,f  2  parts  of  the  former  and  from  1  to  6  of 
the  latter,  and  is  used  for  soldering  coarse  wires.  Silver  solder  may 
be  hard  or  soft,  the  former  containing  1  part  copper  and  4  parts  silver, 
and  the  latter  2  parts  of  silver  and  1  part  of  brass  wire.  It  is  useful 
for  solderim:  fine  wires  and  other  parts  of  eleetrotherapeutic  apparatus. 

The  regular  electric-light  sockets  and  the  lamps  themselves  or  the 
plugs  on  the  flexible  cords  leading  to  a  movable  lamp  are  so  constructed 
that  when  they  are  in  use.  there  are  no  oppositely  charged  surfaces 
exposed  to  accidental  contact.  Xo  shock  or  short-circuit  can  therefore 
occur  in  ordinary  use.  \\hen  the  lamp  is  removed,  two  charged  sur- 
faces  are  expiised:  one.  the  metal  cylinder  into  which  the  lamp  screws, 
and  the  other,  a  metal  spring  which  is  raised  or  depressed  by  the  key 
and  in  this  way  makes  or  breaks  connection  with  a  small  metal  surface 
in  the  base  of  the  lam]).  To  test  the  wires  and  see  if  they  are  charged, 
the  electrician  will  often  moisten  his  finger-tip  and  press  it  against 
these  two  surfaces  inside  of  an  electric-light  socket.  If  there  is  any 
current,  it  is  felt  quite  sharply,  and  usually  causes  the  hand  to  be  drawn 
away  by  a  reflex  contraction.  This  takes  place  whether  the  key  at 
that  socket  is  turned  on  or  not.  If  there  is  no  current,  it  may  mean 
thai  the  dynamo  has  -topped  or  that  there  is  an  imperfect  connection 
vhcre  between  the  dvnanio  and  the  lamp-socket.  Screwing  the 
lamp  it  si  li  into  the  socket  and  t  urn  ing  t  he  key  is  a  more  agreeable  way 
ni  testing  f"i'  current  if  a  lamp  is  available.  But  there  is  no  danger 
irom  the  use  of  the  finger,  ami  no  muscular  contraction  results  which 
will  pp-vent  the  fin»-er  being  withdrawn  at  will.  This  would  be  danger- 
ou-  if  the  person  were  grounded  or  if  the  voltage  exceeded  2")0. 

I'o   locate  the  trouble   in   case  there  is  no  current    try  other  outlets 

•     '        -.:•..<•  circuit.      If  they    have  current,   the  defect    is   probably   in 

'    .'-'  It.   '  ithei    a    faulty  connection    with   the   two   wires  or  an 

•.:>'•':  metallic    connections    in    the   socket.      The    first    is 

>cre\ving  the  wires  fast    in   position:  but  the  latter 

:'•:'•  -   t  lie  use  of  a   I  lew  socket  .       If  1  he  1  rouble   is 
1    '    I  here  is  no  current    at   ot  her  out  let  s  on  the 
.'    I  he  lu.-es  at    the  point    where  this  circuit   leaves 
'    have    burned    ":it.    and    if    so,    thev    must    be 
'  >r   !  hey    r.iav    make   an    imperfect    contact    and 
r   changed    for   new   and 
ar  tin1  mam  switch  bv  which  the 
in    ;     t  he    st  rert     wires    fn  mi    1  he 
l»e    no    current    aliv\vhere    in    t  he 
i!  turned  "ft",  and  simply  turning 
tu.-es  at   i  In-  j mint   may  have 

he 


DYNAMIC    ELECTRICITY 


211 


lino  being  found  to  bo  perfect,  but  the  apparatus  still  receiving  no 
current,  a  break-finder  will  be  found  invaluable.  It  consists  of  a 
16-candle-power  incandescent  lamp  in  a  portable  socket,  wilh  two 
insulated  wires  which  terminate  in  long  metal  points  which  are  insulated 
except  at  their  extremity.  Beginning  at  the  street  mains,  apply  the 
two  points  to  the  bare  ends  of  the  mains  or  to  the  binding  posts  securing 
them.  If  there  is  any  current  there,  the  lamp  will  light  up.  If  not, 
the  electric-light  company  should  be  notified.  If  there  is  current  in 
the  street  mains,  turn  the  main  switch  on  and  test  the  two  bare  ends 
of  the  house  mains  at  the  point  where1  they  are  secured  by  the  binding 
posts  of  the  main  switch.  Finding  no  current  there,  it  will  be  a  simple 
matter  to  remedy  the  defective1  contact  which  this  indicates  at  the 
main  switch.  If  there  is  current  there,  the  next  place  to  be  tested  is 
the  other  end  of  the  house  mains.  The  bare  wires  are  to  be  touched  by 
the  two  points  of  the  break-finder,  and  if  no  current  is  obtained,  it  means 
a  break  in  one  of  the  main  wires  between  this  point  and  the  main  switch. 
This  is  very  unlikely  to  occur  if  unbroken  lengths  of  wire  are  used  for 
these  mains;  but  if  there  has  been  a  joint  in  either  win?,  it  should  be 
exposed  and  will  usually  be  found  to  be  the  seat  of  trouble.  The  two 
ends  of  the  wire  at  this  joint  should  be  scraped  bright  and  clean  of 
oxid.  and  should  be  twisted  together  and  soldered.  The  next  place  to 
be  tested  is  the  beginning  of  the  circuit  in  which  the  current  is  lacking. 
Apply  the  break-finder  to  the  two  bare  ends  of  these  wires,  and  if  there 
is  no  current  there,  the  trouble  lies  in  some  of  the  connections  right  at 
this  point  where  the  current  passes  from  the  house  mains  through  a  fuse 
to  the  distributing  circuit.  Trouble  here  can  usually  be  remedied 
quite  easily  by  tightening  screws  or  putting  in  a  new  fuse.  Finding 
current  in  the  ends  of  the  distributing  circuit  at  this  point,  investigate 
the  ends  of  these1  wires  where  they  are  fastened  to  the  socket  or  knife 
switch  for  the  apparatus.  If  no  current  is  found  there,  the  trouble 
is  due  to  a  break  in  one  of  these1  wires.  They  should  have  been  single 
lengths  of  wire1,  and  if  they  were  not,  the1  imperfect  connection  should  be 
sought  at  the  joint  which  may  not  have1  been  soldered.  Finding  current 
in  the  wires  at  the1  socket  or  knife  switch  and  none  in  the  apparatus, 
the1  break-finder  may  lie  applied  to  the1  contact  surfaces  at  which  the 
current  should  (Miter  the  lamp-base  or  the1  wires  of  the1  apparatus.  The1 
absence  of  current  there  indicates  an  imperfect  connection  in  the  socket 
or  switch,  and  this  is  sometimes  remedied  by  tightening  a  screw  or 
bending  a  spring  into  better 
position,  but  it  often  indi- 
cates the  necessity  for  a  new 
socket. 

A  pole  detector  (Fig. 
105)  makes  a  very  conve- 
nient break-finder  for  anv 
part  of  the  electrotherapou- 
tic  apparatus  itself.  It  will 
show  tlu1  presence  as  we1!! 
as  the'  direction  of  any  cur- 

rent  from  1  to  .")()()  volts.  Connecting  the  two  ends  with  two  oppositely 
charged  wires,  the  passage1  of  the  current  produces  a  chemic  change  in  the 
liquid,  resulting  in  a  ivel  cloud  around  the  negative  electrode.  Its  advan- 
tage1 over  a  lamp  is  that  it  is  sensitive1  enough  for  the  weakest  therapeutic 
currents  and  will  indicate4  without  injury  the  strongest  currents  eve1!'  ap- 


Fitr.  105. — Pole  detector. 


•Jl'J  .Mi:i)H  AL  F.LKC  TiunTY  AND  KONTCKX  RAYS 

plied  ID  medical  :ipp;iratus.  No  other  apparatus  covers  so  wide  a  range 
without  requiring  adjustment.  It  i>  not  suitable  for  the  detection  of 
the  secondary  currents  of  exceedingly  high  potential  and  great  am- 
perage \\hich  are  produced  by  .r-ray  coils,  but  it  is  not  required  for  these 
current^.  a-  they  manifest  themselves  in  a  striking  manner  if  present. 

Pole  Detector.  The  formula  for  the  liquid  is:  50  grams  glycerin;  3 
grains  s;dt peter;  -^  grams  water:  0.5  gram  phenolphthalein;  previously 
dissolved  in  Id  uranis  alcohol.  Pole  connected  with  negative  wire  turns 

violet . 

/•.'.;••'< /'//>"/•':<</  /'"/'  I )>  ft  <•!<»•.-  The  positive  pole  turns  a  raw  potato 
green,  while  the  negative  produces  no  discoloration.  For  110  or  550 
volts  the  pole-  -hould  be  far  apart. 

Measuring  Insulation  Resistance  of  Any  Circuit.— The  apparatus 
required  are  a  voltmeter  of  known  resistance,  about  15.000  ohms,  for 
instance,  and  a  source  of  electricity  such  as  a  series  of  batteries  or, 
preferably,  the  111)  direct  electric  light  current.  The  voltmeter  is  first 
connected  with  the  two  poles  of  the  source  of  electricity;  second  and  third, 
with  one  pole  of  the  generator  and  with  first  one  and  then  the  other  of 
the  wires  of  the  circuit  to  be  tested,  while  the  other  pole  of  the  source 
ot'  electricity  is  grounded.  The  latter  must  be  the  neutral  wire  if  the 
elect  ric  liiili!  current  is  used,  or  if  both  wires  are  charged  this  one  may  be 
grounded  through  an  incandescent  lamp.  This  determines  the  leakage 
from  each  wire  to  the  ground.  Fourth,  the  voltmeter  is  connected  with 
one  pole  of  the  uvnerator  and  with  < me  of  the  wires  to  be  tested,  while  the 
other  of  these  wires  is  connected  with  the  other  pole  of  the  generator. 
This  determines  the  amount  of  leakage  between  the  wires. 


The  formula  is  1!\  ==   Rv  (}  ,  -lY 


Kx  is  the  unknown  resistance.  Rv  is  the  known  resistance  of  the 
voltmeter.  \.  \^  the  electromotive  force  of  the  generator  shown  by  the 
first  voltmeter  reading.  And  F'  is  the  voltmeter  reading  when  in  series 
with  the  unknown  resistance. 

Insulating  Materials.  ln*til<itiu<i  Vdniixhcs.  —Fur  \Yond.  —  Sealing- 
Ivi  d  in  alcoho]  and  painted  on  in  four  or  five  thin  layers. 

/•"'"''   <'/<«""/'/•  ' '<//'/>•.      (ium   copal  dissolved  in  et  her  and  painted 

> '  •    in1   \    '   •      '  .      One  ounce  of  shellac  to  eight   ounces  naphtha  or 
.-I.      This   dissolves   slowly,    and   should   be   filtered,    adding 
-  ...:.-:    :   changing  the  filters  !o  facilitate  that    process. 

u-'    -ix  minces  of  boiled  linsei  d  oil  and  two  ounces  of  spirits 

'       '    '  i II e . 

/'-'/.'     •   '          .      ( 'ot ton-covered  wires  are  soaked  in  melted  paraffin. 

eti    •' roinaLTiiel    coils    ha\e   a    double   layer  of   cotton    thread,  and 

coated   wit  h  a   t  hick  \  al'liish  of  sheila'1. 

'"/    I'ufi' r.      Absorbent     tissiii    paper    is    rendered    insulating 

M  Ited   jiaraflin.  and  is  then  suitable  for  use  as  the  dielec- 

ir^e  ci.mleu.~ers  used   in   telegraphy  and  in  connection  with 

M1  •     lei     paper     M. ill  1     inch    thick,    varnished    with    one 

and    two    parts    -MM'-   o|    i  urpeut  me.    is    reipured 

i.-er  "]     ti  ,      •  •.  coil.      Two  layers  of  t  his  paper  are  required 

'  i"  iwerful  coil-  between  the  layers  of  tin-foil.      These  two  thick- 

hed   paper  are  about  as  thick  as  five  leaves  in  this  book. 

-  i'''  pan-d  b\   soakinjr  j,,  Stockholm  piich    S  nails 

M  'I 


DYNAMIC     KLK(  TKICITY  213 

Wood  is  rendered  insulating  by  boiling  it  in  melted  paraffin  until 
bubbles  of  air  cease  to  rise,  01  by  painting  it  with  melted  paraffin. 

\\'u<xl  is  rendered  both  insulating  and  unaffected  by  acids  if  thor- 
oughly coated  with  Burgundy  pitch,  1500  grains;  old  gutta-percha  in 
shreds,  250  grains;  powdered  pumice,  750  grains.  .Melt  the  gutta- 
percha,  mix  with  the  pumice,  and  add  the  pilch.  An  oak  trough  coated 
with  this  preparation  will  serve  for  years  as  a  jar  for  a  voltaic  or  a 
storage  battery  or  for  an  eleuric  bath.  The  same  preparation  will 
protect  a  metal  tank  used  for  similar  purposes  from  the  action  of  acids, 
but  the  insulation  should  be  supplemented  by  placing  the  tank  on  an 
insulated  support  (wood  treated  in  the  same  way,  or  glass),  and  by  pre- 
venting direct  contact  between  the  tank  and  any  of  the  metallic  wires 
or  elect  rodes. 

Acid-proof  insulating  cctnetit  is  made  by  melting  1  part  of  rubber  with 
2  of  linseed  oil  and  then  adding  2  parts  of  pipe-clay. 

Chattcrton's  compound  contains  Stockholm  pitch,  1  part;  resin, 
1  part:  and  gutta-percha.  •'•>  parts.  It  is  used  for  joining  the  layers  of 
gutta-percha  in  the  insulated  covering  of  wires  and  cables. 

The  dielectric  rit/idih/,  or  the  voltage  required  to  discharge  through 
1  mm.  of  air,  is  4000;  of  mica.  61.000;  of  hard  rubber,  55,000,  and  of 
resin  oil,  20,000.  But  to  have  such  great  insulating  power  the  oil 
must  be  entirely  free  from  water  and  acids. 

Tapping  a  Line  for  an  Additional  Outlet. — It  will  often  happen 
that  one  or  more  outlets  are  desired  from  a  pair  of  1 10-volt  wires  besides 
the  outlet  in  which  the  wires  terminate.  This  can  usually  be  done 
without  disturbing  the  wires  except  at  the  point  where  they  are  to  be 
tapped.  For  instance,  if  the  wires  are  laid  in  molding,  the  capping  is 
removed  and  the  wires  lifted  out  of  the  wooden  groves  for  a  few  inches. 
The  current  should  have  been  shut  off  at  the  main  switch,  and  if  there 
is  a  possibility  of  this  being  turned  on  by  some  one  else,  the  fuse  plugs 
of  this  particular  line  had  better  be  removed.  It  would  be  absolutely 
wrong  to  handle  bare  live  wires  with  metallic  instruments.  Each  wire 
is  tapped  separately.  The  insulating  cover  is  stripped  from  the  wire 
for  about  an  inch,  and  the  wire  is  scraped  free  of  oxid.  The  end  of  the 
wire  that  is  to  be  fastened  to  this  has  been  similarly  prepared  and  is 
wrapped  several  times  around  the  Hue  wire.  The  joint  should  certainly 
be  soldered,  and  this  is  done  by  first  painting  it  over  with  a  xolderitig 
fluid,  such  as:  Saturated  solution  of  /inc  chlorid,  5  parts:  alcohol. 
4  parts;  glycerin,  1  part,  and  then  melting  a  small  amount  of  solder 
over  the  turns  of  wire.  All  the  bare  wire1  should  be  covered  with 
several  layers  of  insulating  tape,  and  the  wire  pressed  back  into  the 
wooden  groove.  The  other  wire  having  been  tapped  in  the  same  way. 
but  at  a  distance  of  about  an  inch  from  the  level  of  the  first,  the  capping 
of  the  molding  is  nailed  down  in  posit  inn  again.  The  two  side  wires 
should  not  be  flexible  wires  leading  directly  to  any  apparatus,  but 
should  be  inclosed  in  molding  and  lead  to  a  stationary  switch-board  or 
receptacle.  At  the  place  where  the  line  is  tapped  the  side  wire  from 
one  n(  the  line  wires  has  to  pass  over  the  other  line,  and  in  doing  so  11 
should  be  outside  of  the  wood  capping.  It  is  often  desirable  to  apply 
a  short  length  of  flexible  loom  or  of  porcelain  tubing  covering  one  wire 
where  it  crosses  t  he  ot  her. 

The  1 10-volt  alternating  current  is  supplied  in  the  same  way  by  a 
three-wire  system.  It  is  a  current  which  produces  a  much  more  marked 
physiologic  effect  than  the  direct  current,  and  so  the  wires  should  be 


21-1  MKDICAL    KLKl  TKK  ITY    AM)    K<")NT<;KN    KAYS 

handled  more  carefully.  While  the  cautious  use  of  the  finger  is  per- 
mi-sible  a-  a  means  of  testing  the  presence  or  absence^  of  current,  still 
it  will  be  found  less  disagreeable  to  use  a  lamp,  a  break-finder,  or  a 
pole  detector  for  this  purpose.  Such  a  current  will  not  flash  across  any- 
greater  -pace  than  the  1  ID-volt  direct  current,  and  requires  exactly 
the  same  -oil  of  wiring.  It  may  be  used  directly  for  running  motors  of 
special  con-truction,  for  diagnostic  and  therapeutic  lamps,  and  for 
electric  baths..  It-  tension  i.-  regulated  by  a  volt  controller,  and  its 
intensity  or  amperage  by  a  choke  or  inductance  coil.  It  may  be  made 
available  for  .r-ray  and  high-frequency  currents  by  means  of  a  rotary 
trail-former  or  electrolytic  rectifier  and  suitable  accessory  apparatus, 
as  was  fir-t  done  in  the  d'Arsonval-Gaiffe  or  the  Snooks  or  Kny-Schcerer 
outfit.  It  is  not  directly  available  for  most  forms  of  electrotherapy,  and 
especially  not  for  elect  rodiagnosis  where  a  polar  effect  is  often  essential, 
tint  it  may  be  used  to  run  a  motor  generator  from  which  a  suitable  current 
with  a  fixed  polarity  may  be  obtained.  It  may  also  be  used  to  run 
a  motor  transformer  yielding  a  sinusoidal  current,  which  has  very 
marked  therapeutic  properties. 

The  intensity  of  an  alternating  current  may  be  measured  by  means 
of  a  hot  wire  milliamperemeter.  The  current  or  a  shunted  portion  of 
the  current  passes  through  a  wire  whose  increase  in  length  under  the 
influence  of  heat  causes  a  corresponding  motion  of  the  indicator.  The 
in-trument  is  graduated  by  experimental  comparison  with  a  standard 
in-trument.  The  wire  is  heated  by  a  series  of  currents  in  alternating 
directions,  very  much  as  it  would  be  by  a  scries  of  currents  in  the  same 
direction.  The  voltmeter  for  alternating  currents  must  also  be  a  hot- 
wire in-t  rument .  Taking  t  he  number  of  volts  and  of  amperes  indicated 
by  the  two  instruments  and  multiplying  these  together  to  obtain  the 
indicated  number  of  watts  produced  by  the  dynamo,  it  will  often  be 
found  to  exceed  the  amount  of  power  expended  in  running  the  dynamo. 
Tin-  hot  wire  milliamperemeter  evidently  does  not  register  the  average 
strength  of  the  currents  passing  through  it  in  alternate  directions,  but 
tes  somewhat  more  than  the  true  figure.  The  repeated  surges 
heat  pi  dui'ed  by  the  maximum  current  are  more  effective  than  t  he 
d'-ncv  on  the  part  of  the  wire  to  cool  during  the  instants  when  the 

1  •    '    '      i-     /••!''  i. 

Trolley-car  Currents.     The  .">()()-  or  .">.">( )-volt  direct  current   of  the 
•••••••.   used   for  electric  arc-lamps  in  the  street    and  public 

-udi   high   potential   that    it    will   leap  across  a  considerable 
dangerous  effect  upon  living  creatures.      Death 
nt    passing   through    the   body   bv   accidental 
oppM-iie]y  charged  bare  wires,  or  \ynli  one  bare  wire 
"  i!  'i  cotin"ciioii.      Tin-  person  may  escape  with  only 
n    i'    he   i-   in   a    partially   insulated  position   and 
The  wires   are   not    only   a   direct    danger,   but 
ires,  telephone  or  telegraph,  may  fall  across 
an   being-.       lf<ir-es  are  -aid  to  be  more  apt 
••'i<l   n    ma;     be  in  -cause  their  iron  shoes  form  a 
\]     in-ula  t  <  •!     boi  1\    when  brought   near  to  or 
'•  "  "1\    aci  •  . ,   a   slight    extent    as  a   con- 

It    acts  like  a  container 
I  i-  poured.  ;md  mil    like  a  sect  ion 
''  'Ugh  •  ci  .Hi  inui  in.-  -t  ream   is  poured. 

. 

-  |p  . ' ':!-  c    pa  city    pa --ing  i  h rough  t  he  sect  ion  of  pipe 


DYNAMIC    ELECTRICITY  215 

in  a  second.  A  short  length  of  fine  wire  suspended  by  a  silk  thread 
mav  he  swung  into  contact  with  a  hare  wire  charged  with  elect ririi  v 
at  a  voltage  of  550,  and  will  he  found  to  have  received  a  charge  of  elec- 
tricity, hut  only  a  very  slight  one  as  compared  with  what  it  would 
receive  from  contact  with  the  prime  conductor  of  a  static,  machine. 
The  wire  undergoes  no  appreciable  change,  and  if  swung  away  from  the 
550-volt  conductor  and  against  one's  hand,  its  electric  charge  will  be 
hardly  perceptible.  But  the  same  fine  wire  will  be  heated  and  fused 
or  even  vaporized  if  it  crosses  two  oppositely  charged  wires  with  a 
550- volt  potential,  or  if  it  forms  a  conducting  path  between  one  of 
these  and  the  earth.  Insulating  the  human  body  and  then  touching 
a  bare  550-volt  conductor  is  not  to  be  recommended  as  an  experiment: 
it  is  only  referred  to  at  this  place  to  show  the  direction  of  safety  and  of 
danger  in  the  management  of  such  a  current. 

A  550-volt  current  is  entirely  unsuited  to  any  elect  rot  herapeutic 
application.  It  must  be  changed  to  a  current  of  a  much  lower  potential, 
and  this  cannot  be  economically  done  by  a  volt  controller.  This  would 
involve  a  great  waste  of  power,  sending  three-quarters  of  the  current 
through  a  parallel  and  unused  path,  and  also  producing  an  amount  of 
heat  in  the  side  conducting  path  which  would  require  special  arrange- 
ments to  guard  against  fire.  The  same  overheating  would  occur  if 
reliance  were  placed  upon  a  rheostat.  Unless  the  electric  company  is 
willing  to  do  so,  it  will  be  necessary  for  the  physician  to  have  a  motoi 
generator  or  a  transformer  to  produce  the  desired  current  — 110  volts 
or  less.  The  motor  generator  is  the  proper  apparatus  for  use  with  the 
direct  current.  It  is  a  motor  actuated  by  the  550-volt  current,  and 
running  a  dynamo  which  may  be  constructed  to  generate  a  current  of 
any  desired  voltage,  either  direct,  alternating,  sinusoidal,  or  poly- 
phase. The  closed  magnetic  ring  transformer  converts  the  power 
of  a  550-volt  alternating  current  into  an  alternating  current  of  any 
other  desired  voltage  by  a  process  of  induction  which  takes  place 
between  two  stationary  coils.  The  rotary  transformer  is  for  the 
same  purpose  in  connection  with  the  direct  current,  but  looks  like 
a  dynamo  or  motor  generator,  and  in  it  the  charged  coils  of  wire  are 
rapidly  rotated.  The  ease  with  which  the  alternating  current  can  be 
changed  in  voltage  by  a  transformer  without  any  movable  parts  and 
without  any  sparks  or  bare  charged  wires  makes  it  very  convenient 
commercially.  There  is  a  wonderful- economy  in  the  weight  of  copper 
wire  tor  the  long-distance  transmission  of  power  as  an  electric  current 
of  very  high  voltage  -10.000  or  15.000  volts.  The  same  amount  of 
power  as  a  current  of  500  volts  would  have  20  or  .'>()  times  the  amperage, 
and  would  require  400  or  !)()()  times  as  great  a  conducting  path.  Accord- 
ing to  .Joule's  law,  the  amount  of  heat  disengaged  in  a  given  time  is 
directly  proportional  to  the  square  of  the  strength  of  the  current  and 
to  the  resistance.  The  strength  of  the  current  means  the  number  of 
amperes  or  milliamperes.  It  will  readily  be  seen  that  the  higher  volt  ani's 
are  an  absolute  necessity  when  it  comes  to  a  matter  of  transmitting 
thousands  of  horse-power  as  an  electric  current.  These  tremendous 
voltages,  ot  course,  need  the  hrnrfmt  kind  of  insulation  wherever  they 
touch  any  solid  support,  and  require  that  the  conductors  should  not  be 
on  the  surface  of  the  ground,  and  that  they  should  he  far  enough  apart 
from  each  other  or  tn>m  other  metallic  conductors  to  prevent  the 
current  from  leaping  across  the  air-space  which  forms  the  insulation. 
Accidental  contact  of  human  beings  with  the  metallic  conductor.-  should 


i?lti  MKDK  AI.   Ki.KeTKieiTY  AND  HOXTGEN  HAYS 

lu1  mo-t  effectually  guarded  against,  as  it  would  certainly  be  fatal. 
(  'urrents  «>f  such  tremendous  voltage  are  always  modified  hy  a  step-down 
transformer  before  entei-inir  tin-  powe:  -house,  where  they  are  further 
acted  upon  hv  rotary  converters  and  changed  into  a  direct  ciiri'ent  of 
.').">(  i  vohs  for  the  trolley  line.  and  of  other  voltages  for  charging  storage 
batteries  and  fur  elrciric  lighting.  Almost  any  bare  wire  or  binding- 
|i  -•  in  -uch  a  power-house  is  charged  witli  a  current  which  would  make 
intact  extremel  dangerous.  There  is  also  a  great  amount 


these   lii^h    voltages   and   rapid   alternations   are   present, 
effects  are  produced.     One  is  a  magnetizing  tjhct  upon 
using  them  to  run  irregularly,  and  another  is  an  effect  upon 
ni  ••"..-  .-  •  .*?<  '"   of  the  operatives,  producing  symptoms  of  neuras- 
.:;:.      The  air  of  the  room  is  kept  warm  by  the  conversion  into  heat 
certain  portion  of  the  electric  current  passing  through  the  various 
iii-  i  >f  t  he  apparatus. 

The  best  conductors  are  those  which  transmit  an  electric  current 
the  least  ohmic  or,  in  other  words,  frictional  resistance,  hut  there 
i-  ;il\vavs  some  resistance1,  and  in  the  case  \ve  are  considering  the  resist- 
ance is  iioi  only  a  measurahle  hut  a  large  quantity.  The  electricity 
lost  hy  ohmic  resistance  is  converted  into  heat.  Special  attention  is 
always  paid  t"  arrangements  for  the  dissipation  into  the  air  of  the  heat 
produced  by  ohmic  resistance  in  the  wires  forming  part  of  dynamos 
and  motors.  A  rise  «i  .">()-  F.  in  the  temperature  of  the  apparatus  is 
regarded  a.-  t  he  limit  of  safety.  The  hotter  a  body  becomes  as  compared 
\viih  the  surrounding  atmosphere,  the  more  rapid  becomes  the  dis- 
sipation  of  the  heat.  In  an  apparatus  through  which  the  same  amount 
uf  electricity  passes  every  minute  ami  in  which,  consequently,  the 
same  amount  of  heat  is  tienerated  every  minute,  the  maximum  tem- 
peraHire  attained  is  the  temperature  at  which  the  rate  of  dissipation 
:  deal  becomes  eijiial  to  the  rate  of  heat-production.  The  room  in 
which  all  these  great  dynamos  are  in  operation  is  so  warm  that  no 
artificial  heat  is  required,  and  the  doors  and  windows  are  left  open. 

The  ureat  copper  bars  forming  the  ground  connection  or  return 
circuit  fi'Min  the  trolley-car  rails  to  the  dynamo  carry  a  tremendous 
amperage,  but  a  very  low  voltage.  These  can  be  touched  with  the  bare 
hand,  and  are  found  to  feel  quite  warm  from  the  friction  of  the  electric 
current  pa  --in  si  through  them.  One  of  these  bars  carries  a  current 
-utheieiii  in  kill  1  ou  men,  hut  its  ground  connection  and  approximately 
zero  voltage  make-  it-  pres-uiv  so  low  that  the  amount  which  will  pass 
through  the  human  hodv  i-  not  sufficient  to  produce  a  perceptible  sen- 
ount  i-  found  1  iy  dividing  t  he  voltage  by  the  number  of 
MI  the  body,  and  i-  not  exceeded  no  matter  what  may 
an  i  per;  tire  of  t  he  generator. 

i  ill   current  i.f  the  trolley-car  circuit  or  the  10.000- 
•  i    for   long-di.-tance   1  ran.-mi»ion   of  power  pa->e- 


ent  lamp  upon  a  writing  desk.     And  just  as 
current  u  ill  cau.-e  heal  enough  to  vaporize 
er    currents    \\ilh    lieavier    voltages    and 
struct ive  incfiagrations  when  short-circuited. 
are  always  employed,   breaking  the  circuit 
•ive  current   be^in-  to  flow  throuirh  the  line. 


DYNAMIC    ELECTRICITY 


217 


A  circuit-breaker  is  like  ;v  knife-switch,  which  is  thrown  wide  open 
by  the  action  of  ;in  electromagnet  which  is  not  strong  enough  to  throw 
open  the  switch  with  any  ordinary  current,  but  becomes  so  under  the 
influence  of  an  abnormally  strong  current. 

A  common  use  of  the  circuit  breaker  is  in  an  automatic  cut-off  ar- 
ranged to  break  the  circuit  in  case  of  an  excessive  Mow  of  current.  A 
powerful  spring  tends  at  all  times  to  press  the  control  lever  over  to  "off," 
or  the  position  of  no  current.  When  this  lever  is  pressed  over  to  the 
place  of  maximum  current  flow  it  is  held  there  by  a  powerful  electro- 
magnet. Forming  a  part  of  the  same  apparatus  is  another  electro- 
magnet which  tends  constantly  to  actuate  a  circuit  breaker,  but  is  opposed 
by  a  spring  which  may  be  set  so  that  it  will  yield  to  more  than  a  definite 
strength  of  current.  An  excessive  current  causes  the  circuit  breaker  to 
act;  the  electromagnet  loses  its  power  to  hold  the  resistance  lever,  and 
the  latter  springs  back  through  the  positions  of  greater  and  greater 
resistance1  to  that  of  no  current.  This  is  part  of  the  equipment  of  any 
powerful  x-ray  generator. 

The  induced  currents  produced  for  therapeutic  application  by  a 
faradic  coil  are  of  a  higher  voltage,  and  correspondingly  lower  amperage 
than  the  primary  current.  The  faradic  current  will,  therefore,  over- 
come the  resistance  of  the  dry  skin,  and  two  dry  uncovered  metal 
handle's  held  in  the  hands  will  transmit  a  current  through  the  1000  ohms 
resistance  of  the  body.  A  voltaic  current  of  the  usual  voltage  would 
not  be  transmitted  in  any  effective  amount  under  the  same  conditions. 
The  faradic  current  is  usually  an  alternating  and  an  interrupted 
one,  and  each  impulse  varies  in  voltage  from  a  maximum  to  a  minimum. 
Methods  of  measurement  of  the  voltage  arc1  by  the  use  of  a  faradimeter 
or  of  an  electrostatic  voltmeter.  The  latter  depends  upon  the  attrac- 
tion between  two  oppositely  charged  bodies,  while  the  faradimeter  is 
composed  of  two  coils  between  whose  ends  a  bundle  of  soft-iron  wire  or 
a  coil  of  wire  is  freely  suspended.  The  soft-iron  core  tends  to  assume 
a  position  parallel  with  the  long  axis  of  the  coils,  and  indicates  upon 
a  dial  the  strength  of  the  current  passing  through  the  coils.  The 
strength  of  the  current  is,  of  course,  dependent  upon  the  voltage. 
Either  of  these  appliances  probably  gives  an  approximation  to  the 
maximum  voltage  and  not  the  average  voltage.  Measurements  have 
been  made  which  indicate  that  the  potential  of  a  faradic  current,  while 
actually  being  applied  to  a  human  being,  is  about  10  volts,  while  other 
measurements  indicate  that  the  difference'  in  potential  between  the' 
two  pole's  on  ope'ii  e-hruit  is  about  90  volts.  As  it  take's  a  voltage'  of 
about  10,000  to  spark  across*  an  air-space  of  an  inch,  the  spark  to  be 
obtained  from  10  volts  would  be  only  ,,/,,,,  or  ..-j-,1,;,,  ine-h  long,  ami  that 
Iroin  90  volts  about  -,  ,1M)  or  3/M,  inch  long.  And  this  is  about  the  result 
obtained  when  the  two  bare  ends  of  the  wires  from  a  faradic  coil  are' 
brought  together;  it  is  difficult  to  get  any  spark  at  all  e'xcept  by  rubbing 
the  ends  over  each  other  and  securing  an  imperfect  contact.  It  is 
hardly  possible  to  hold  the  e-nds  at  any  distance  apart  and  secure-  a 
continuous  strc'am  of  sparks.  With  the  strongest  therapeutic  faradic 
current  the  sparks  that  can  be  obtained  are  little  bright  points  without 
noise  and  without  any  c't'fect  upon  the  metal  points.  The'  amperage 
is  very  small  indeed.  As  in  the  case  of  the  voltaic  current  for  medical 
purposes,  the'  wire's  carrying  the  faradic  current  ivquiiv  nothing  but  the 
thinnest  complete  layer  of  insulating  material. 


MKDICAL    KLK(  THICITV    AM)    ROXTGEN    KAYS 


The  Different  Wire  Gauges.  The  one  usually  referred  to  in 
America  when  the  si/e  of  a  wire  is  spoken  of  as  such  a  number  is  the 
Brown  and  Sharpe  wire  gauge  (B.  S.  (1.).  For  example,  the  No.  3(> 
wire  so  generally  employed  for  (he  secondary  coils  in  faradic  or  rr-ray 
apparatus  i-  No.  oti  B.  and  S.  The  other  gauges  are  British  Standard 
(Jaime  (S.  \V.  (I.):  the  Birmingham  Wire  ( Jauge  (B.  W .  (',.);  and  the 
French  Wire  (Jaime  ( F.  W.  (i.i.  In  addition  to  these  gauges  in  which 
wire  i<  referred  to  by  number,  the  size  of  a  wire  may  be  designated  In- 
stating it^  diameter  in  fractions  of  an  inch  or  in  millimeters. 

NIL  :>»>  (]•>.  and  S.)  is  ().()().")  inch,  or  0.1  millimeter  in  diameter.  Its 
equivalents  are  Xo.  10  (S.  W.  (!.)  and  Xo.  '•'>•")  (B.  \\'.  (I.i.  It  is  used 
fur  the  secondary  "f  induction  coils. 

\o.  '2'2  i  B.  and  S.i  is  o.0_'.~>:>  inch  or  0.0  millimeter  in  diameter.  Its 
equivalents  are  Xo.  2:!  (S.  \\'.  (',.).  Xo.  2M  (  B.  \\".  (J.)  and  Xo.  1 
i  F.  \\".  (i.).  It  is  useil  in  the  primary  windi.-g  of  induction  coils. 

Xo.  1  1  (  B).  and  S. )  is  O.Oli  1  1  inch  or  l.l>  millimeters  in  diameter.  Its 
equivalents  are  Xo.  Ki  (S.  W.  (i.).  Xo.  Hi  ( B.  W.  (J.).  and  Xo.  11 
( F.  \V.  ('<.<.  It  i-  used  for  the  house-wiring,  passing  from  the  mains 
to  individual  elect  ric-li.Liht  sockets. 

Xo.  lo  '  I  >.  and  S.)  is  o.  10 1  0  inch  or  '2.1  millimeters  in  diameter.  Its 
equivalents  are  Xo.  12  (S.  W.  (J.).  Xo.  1_'  (\>>.  W.  (i.).  and  Xo.  Hi 
(  F.  \\  .  (J.).  It  is  a  suitable  si/e  tor  the  house-wiring  leadmii  from  the 
mains  to  the  switch-board  for  an  /-ray  coil  or  to  an  arc-lit^ht .  It  is 
heavy  enoiiirh  even  fur  the  main-  for  an  elect r< (therapeutic  installation, 
ided  that  not  more  than  about  2">  amperes  of  current  in  the  various 
apparatus  are  ever  to  he  turned  on  at  the  same  time. 

Xo.  s  i  B).  and  S.i  i-0.1_N.~>  inch,  or  .'!.-!  millimeters  in  diameter.      Its 

equivalents     are     \o.    10     (S.   W.  (i.).    Xo.    10     (  B.   W.  (J.),    and    Xo.    Is 

I-'.   \V.  (i.).      It    i-  .-uitable   for  the   mains   for  a   complete  elect  n>i  hera- 

peutic  installation,   indndinfi  .''-ray.  sire-light,  and  electric-light   baths. 

but    not   to  exceed    100  amperes  at   aiiv  one  time. 


is 


DYNAMIC    KLECTPTCITY  219 

Conductivity  of  Metal  Wire*. — The  specific  conductivity  of  pure 
silver  wire  is  taken  as  100,  that  of  pure  copper  wire  is  80,  and  the  con- 
ductivity of  copper  wire  suitable  for  electric  work,  95  per  cent,  that  of 
pure  copper.  The  specific  conductivity  of  silver  is  100;  copper,  80; 
gold,  55;  xinc,  27;  tin,  17;  iron,  14;  palladium,  12.5;  platinum,  10.5; 
lead,  7.8;  antimony,  4.3;  mercury,  1.6;  bismuth,  1.2.  This  means  that 
under  identical  conditions  as  to  voltage  and  size  and  length  of  wire  the 
strength  of  current  transmitted  will  be  in  the  proportion  indicated  by 
the  specific  conductivities. 

Units  of  Resistance.-  In  the  ('.  (i.  S.  system  the  unit  of  resistance 
is  that  of  a  pure  copper  wire  one  millimeter  in  diameter  and  TTOIM/TJ 
millimeter  long. 

In  the  system  commonly  employed  the  unit  of  resistance  is  the  ohm, 
which  is  equal  to  the  resistance  of  a  pure  copper  wire  one  millimeter 
in  diameter  and  48.64  meters  long.  For  other  values  of  the  ohm  see 
page  49. 

The  Specific  Rcxixtancc  of  Metal  Wirex. — The  specific  resistance  of 
pure  copper,  or  the  resistance  of  a  cubic  centimeter  at  0°  C.  is 
0.000001642  ohm.  The  specific  resistance  of  the  various  other  metals 
is  a  matter  of  simple  calculation  based  upon  a  comparison  of  their 
conductivity  with  that  of  copper.  For  instance,  platinum  has  about 
one-eighth  the  specific  conductivity  of  copper,  and  has,  therefore, 
about  eight  times  the  specific  resistance.  A  pure  copper  wire  1  square 
centimeter  in  cross-section  and  1  centimeter  long  has  a  resistance  of 
0.000001642  ohm,  and  100,000  times  that  length,  or  a  kilometer 
(equal  to  3280.9  feet)  of  the  same  wire  would  have1  a  resistance  0.1642, 
or  about  ,';  ohm. 

/iV.svW /V/i/y  is  expressed  in  ohms  per  circular  mil.  foot  (conductor  1 
foot  long  and  with  a  circular  cross-section  i,,',,^  inch  in  diameter). 

Current  denxiti/  is  expressed  in  amperes  per  square  inch  of  cross- 
section  or  0.000001  ampere  per  circular  mil. 

TABLK  OK  TIIK  RK.SISTANVK  OK  IHKKK.KKXT  MKTAL  WlKKS. 

RESISTANCE  or  A  WIKK 
1  MKTKK  I.OM,  ANI>  1 

MlI.I.I.MKTKH   IN  DlAM- 
ETER. 

0.01'.i:;7  ohm 

().020.-)7  " 

0.021 '),")()  " 
O.o:i7.")l 

O.lKidO  '• 

0.1 2.")  10  •' 
0.2.V2(>0 

1.22170  •' 


APPROXIMATE 

N  XMI-:   or   MKTAI.. 

CoMI'AU  \TI\  }•'. 

RESISTANCE. 

Silver 

1   1)0 

<  'opper.  . 

1  .01) 

[    1                                           

Cold  

Aluminum   

1  'M 

I'lat  inum  

(i.OS 

Iron 

(i.XO 

Lead 

1  '•'>  (iO 

Mercury,  liquid  

'  HTiuan-Mlver        i  copper. 

t: 

nickel.  2:  /.inc.  1  .  part<  i. 

7  '*'' 

I  he  resistance  ot  any  Icngih  of  wii'c  of  ;ni\'  dianu'ter  may  l»c  cal- 
oulated  troin  this  lable.  .Mulliply  the  I'csistance  of  one  nielei1.  as  iri\-ct: 
abov(\  hy  the  mimlier  of  meters,  and  divide  by  the  square  of  the  diametei 
expressed  in  millimeters.  Thus  the  resistance  of  a  copper  wire  V, 
millimeter  in  diameter  and  ion. ()()()  meters  Inng  would  be  found  by  ilu- 
following  e(|uai  ion: 


220  MKDIfAL    KI.KC THK  ITY    AM)    RONTGEN    HAYS 

This  is  the  -i/e.  No.  o<>.  B.  \V.  (i.,  and  length  of  the  secondary  wire  in 
>ome  Ill-inch  induction  coils.  The  'J(M ).()()()  ohms  resistance  is  what  might 
be  termed  the  frictionai  resistance,  and  causes  loss  of  power  by  convert- 
ing a  certain  amount  of  the  electric  energy  into  heat.  The  other  im- 
pedence  to  the  ilo\v  of  the  current  is  inductance,  and  is  dependent  on  the 
number  and  arrangement  of  the  number  of  turns,  not  on  the  length  and 
thickness  of  the  wire.  It  is  not  under  consideration  at  this  place. 

SL'/n  fcn'td.-  Simple  experiments  show  that  a  charge  of  static 
electricity  i-  practically  all  upon  the  surface,  due  to  the  repulsion  of 
charges  of  the  >ame  polarity,  \Yith  dynamic  electricity  the  direct 
current  shows  practically  no  skin  effect,  but  with  1  lie  alternating  current 
tin.-  effect  i-  very  marked.  The  current  is  to  a  large  extent  confined  to 
the  surface  of  the  wire  and  comparatively  little  is  transmitted  by  the 
interior  of  the  wire.  This  reduces  the  conducting  capacity  and  has  the 
effect  of  increasing  the  resistance  of  the  wire.  This  cannot  be  overcome 
by  lining  a  stranded  conductor,  the  resistance  from  skin  effect  remaining 
the  same.  Hut  a  I  a  rue  wire  sometimes  is  made  with  a  non-conducting 
core  -ii  that  the  same  weight  of  metal  with  a  larger  surface  for  conduc- 
tion will  have  le<s  resistance  due  to  skin  effect. 

( lerman-silvcr  wire  is  frequently  used  for  rheostats  and  other 
resistances,  and  the  foregoing  table  enables  one  to  calculate  the  resist- 
ance of  a  certain  length  of  wire  of  a  certain  diameter.  The  following 
table  \vill  also  lie  found  of  value. 

RKSISTAXCK    o\-    :;r,    LXCHKS    ()\-    (iKKMAN-SII.VKH    \\IRF.    AT    (10°    K. 


I). i)7(l()() 
o.:i»soo 


Silicioiis  bron/.e  has  almost  the  conductivity  of  copper,  i.  c,7  tunes 
|e-r-  resi.-talice  iliaii  iron,  and  hroii/e  wire-  Weighing  I  ( II )  pounds  to  the 
IMS'!''  can  be  substituted  for  iron  wires  wit h  great  economy  in  cost  and 

:  •  asc   in   conduct  iv it  V. 

l-'illimi  n   Itnhhin   In  (i   drlnin    //<  >/>/</ t,n  .      If  the  outer  diameter  of 
the  coi]  oi   wire  i-  to  lie   .1,  and    the  inner  diameter  n.  and  its  length  l>. 
-•••'.'•••  required  i-  II.  and  /'  is  the  radial  thickness  of  the  insulated 
wrap: 'in ^      I   the  wire.       I  he  diameter  </  of  the  wire  which  will  till  such 
a   bobbin    and    produce  the   required    resistance  i-   found  bv   the  e 
•     V         a 


id    by    1  he   equal  i<  >\\ 
.  1 1 1 1  >  i  .!-.•     -  L     iii,    i  n  1 1  1 1 1  a  n  i  et  e  r  ol  t  lie  w  i  re,  m- 

'  'r  another  torn nila  i-:     add  t  he  t  hickliess  of  t  he 
'      :         ejej-  ,,]'  t  he  core  .  ititside  of   its   itisulat  ion,   mult  ipiy   by 
'  '  ••    1'  :.  L1 '  :..  and  a  Ha  in  by  t  he  I  hick  ness  of  t  he  coils  f  A      a  i. 
1  '  .    t  hi     -qiiari    o|    t  he  diameter  i  if  t  he  wire. 


DYNAMIC    KLKCTKICITY  221 

The  number  of  turnx  of  wire  in  n  coil  is  found  by  multiplying  the 
thickness  of  the  coil  (A  a  of  the  previous  paragraphs)  by  its  length 
and  dividing  by  the  square  of  the  diameter  of  the  wire. 

The  total  treit/lit  or  rcxi*/a-ncc  is  easily  found  from  one  of  the  printed 
tables  if  the  length  and  diameter  of  the  wire  are  known. 

fcjl'ccl  of  Temperature  n/>on  ffcxixtctncP.—Thix  has  to  lie  taken  into 
account  in  some  of  the  commercial  uses  of  electricity,  but  it  is  so  small 
that  it  mav  be  disregarded  or  only  approximately  calculated  in  electro- 
therapeutics. The  resistance  of  a  copper  wire  increases  about  one-fifth 
of  1  per  cent,  for  each  degree  F.,  or  1:\1S0  of  1  per  cent,  for  each  degree  ('. 
that  the  temperature  rises.  A  Gorman-silver  wire  shows  an  increased 
resistance  of  only  one-twentieth  of  1  per  cent,  for  each  degree  ('.  that 
the  temperature  rises. 

Tin  Production  of  II  eat  m  ( 'ortducfitif/  liV/v-N.  The  ohmic  resistance 
of  a  conducting  wire  is  a  measure  of  the  power  which  would  be  required 
to  simply  make  t  he  current  flow  1  h rough  the  wire  if  the  wire  were  st  might 
and  uninfluenced  by  any  other  object.  This  portion  of  the  power  from 
the  generator  corresponds  to  the  power  lost  bv  friction  in  ordinary 
machinery.  None  of  the  elect  ric  power  so  consumed  is  act  ive  in  inducing 
other  currents  or  in  causing  mechanic  motion.  It  is  converted  into 
heat.  The  heat  produced  in  this  way  varies  directly  as  the  resistance 
and  as  the  square  of  the  current  or  amperage.  The  power  wasted  in 
simply  overcoming  what  mav  be  considered  the  frictional  resistance 
to  the  passage  of  the  current  through  the  wire  also  varies  directly  as  the 
resistance  and  the  square  of  the  amperage. 

The  following  formula  enables  one  to  calculate  the  number  of  horse- 
power wasted  in  the  form  of  heat  by  the  passage  of  a  current  of  elec- 
tricity through  a  wire: 

II  P  =     r-R     y.,     0.001:54. 

746 

The  actual  amount  of  heat  generated  in  a  given  time.  T.  is  equal  to 
("-'RT>:  0.240")  (gram-degrees).  In  this  formula  ("•  is  the  square  of  the 
number  of  amperes.  R  the  number  of  ohms  resistance,  and  T.  the 
number  of  seconds  that  the  current  flows.  The  product  of  these  three 
factors  is  to  be  multiplied  bv  0.210.")  to  find  the  number  of  gram-degrees 
or  calorics.  One  calorie  is  the  heat  required  to  raise  the  temperature  ot 
one  gram  of  water  one  degree  ( '. 

'I  In  ///>•(  uj  TI  ni/n  ratun  in  a  ( 'OIK/ net / n</  II  ii'C.  —  This  will  depend 
partly  on  the  amount  of  heat  generated  in  it  in  a  given  time,  and  partly 
on  the  rate  at  which  tins  heat  escapes  from  the  wire.  The  larger  the 
wire,  the  less  will  be  its  resistance  and  the  less  heat  will  be  generated 
in  it.  but  there  is  alwavs  some.  Insulated  wire  for  the  mains  and  the 
separate  circuits  of  house-wiring  should  be  of  such  a  size  that  its  tem- 
perature will  noi  rise  more  than  2~>D  or  ill)3  F..  no  matter  how  loiiii  the 
current  flows.  A  good  empirical  rule  is  that  a  copper  conductor  2  inches 
in  diameter  will  safelv  carry  a  current  of  21  )l  !0  amperes,  and  that  the 
sate  carrving  capacitv  of  wires  of  greater  or  less  diameter  vanes  as  the 
square  root  of  the  third  power  of  the  diameter.  An  example  oi  the 
application  of  this  rule  would  be  in  finding  the  safe  carrying  capacity 
of  a  Xo.  1  1  l'>.  \Y.  ( i.  wire,  which  is  about  O.Os  inch  in  diameter.  ( 'ailing 
the  unknown  carrving  capacitv  A 


222  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

1  2:t   "  :       i   O.OS'     :  :     2000     :     A". 

!    2"     .V  j   O.OS1    2000. 

!    O.OS:1     2000  2000  0.022(13 

A  Xo.  14  copper 'wire  will  accordingly  carry  a    Hi-ampere  current 
without  overheat ing. 

I.FNV.TH.   \VI-:K;HT.   AND   RKSISTANCF.  or    COPPER   WIRE. 

iNi>  WKK.HT. 

Pot    Mis   I'KR 


w.  <;. 

WK.II;IIT  \M> 

1  .  E  N  i  .T  H  . 

l.KVCTH    AM) 

KKSISI  ANCK, 

RESIST.* 

<  hl.Ms    I'Kli 

l'i  H    M»    I'KH 

<  >HMS   1'1-:K 

Mll.K. 

MILE. 

I'oi  vi). 

X 

13.").  0(1 

2.00 

0.00460 

in 

2s7.UO 

3.03 

0.01058 

14 

IS'UHl 

4..")0 

0.02416 

20 

I'.t.OO 

44.49 

2.27254 

2  t 

7.  SO 

112.02 

14.55700 

30 

2.30 

37S.;.l 

164.46500 

30 

0.2") 

3400.00 

13200.00000 

Tin  flmt i m/  i'j  Coil*  of  \Yirc  h/i  a  Current. — The  heat  develojiod  in 
clnsrly  \viiuiid  mils  of  wire,  as  in  dynamos  and  .r-ray  coils,  finds  a  com- 
paratively small  radiating  surface,  practically  only  the  outer  surface 
of  the  outermost  layer,  and  a  greater  rise  of  temperature  will  result. 
A  rise  i  if  .")()-  ('.  is  considered  safe  for  the  wires  in  the  electromagnets 
of  a  dvnamo.  (ienerally  speaking,  wires  are  considered  to  be  over- 
heated when  they  are  too  hot  for  the  hand  to  lie  kept  upon  them  for  a 
minute  at  a  time  without  discomfort.  Bobbins  of  the  same  size'  when 
wound  with  wires  of  different  calibers  contain  a  length  of  wire  which  is 
inversely  proportional  to  the  square  ot  the  diameter  of  the  wire.  The 
resistance  m  such  bobbins  is  inversely  proportional  to  the  fourth  power 
ol  t  he  diameter  ol  i  In •  wire.  T<  i  -ecuiv  equal  heating  in  t  he  I  wo  bobbins 
the  current  strength  in  ampere.-  divided  by  the  square  of  the  diameter 
of  tin'  wire  should  give  the  same  number  in  both. 

NATIONAL   HOARD  OF    FIHK    r.NDKIUYKITKKS'  TABLK  OF  C\HRYlN(i 
CAPACITY    OF    \YIHF.S. 


Is  :  i  .1 

Hi  0  s 

M  12  1C, 

12  17  23 

in 


DYNAMIC    ELECTRICITY  223 

The  safety  limits  arc  those  within  which  there  is  no  danger  of  injuring 
the  insulation  of  the  wires  in  the  coils.  Coils  in  which  the  wire  is  2 
millimeters  in  diameter  can  safely  carry  about  15  amperes;  and  with 
wire  5  millimeters  in  diameter,  about  (H)  amperes. 

The  lower  limit  is  specified  for  rubber-covered  wires  to  prevent 
gradual  deterioration  of  the  insulating  property  by  the  heat  of  the 
wires,  not  from  fear  of  igniting  the  insulation.  The  question  of  drop 
is  not  taken  into  consideration  in  the  foregoing  tables. 

No  smaller  wire  than  No.  14  should  be  used  for  regular  wiring. 
"Circular  mils"  refers  to  the  area  of  cross-section  of  the  wire.  One 
mil  is  one-thousandth  of  an  inch,  T7j'nTr  inch,  or  0.001,  and  the  area 
of  a  square  which  is  one  mil  on  each  side  or  one  square  mil  is  0.001 
X  0.001  =0.000001  square  inch.  One  square  mil  is  0.000001  square 
inch;  1624  square  mils  is  0.001620  square  inch.  The  area  of  a  circle 
which  is  0.001620  square  inch  is  also  denominated  1620  circular  mils. 
The  area  of  cross-section  of  a  No.  18  B.  and  S.  G.  wire  is  1620  circular 
mils,  or  0.001620  square  inch.  Each  mil  in  the  diameter  of  a  wire 
indicates  0.001  inch.  Each  "circular  mil"  in  the  area  of  cross-section 
of  a  wire  indicates  one-millionth  of  a  square  inch. 

The  Insulation  of  Wires. — This  includes  all  the  means  which  are 
taken  to  limit  the  flow  of  electricity  as  much  as  possible  to  the  wire 
itself,  and  the  apparatus  to  which  the  current  is  led  and  through  which 
it  is  intended  to  flow.  Leakage  of  electricity  may  take  place  from  one 
charged  wire  to  another,  or  directly  or  indirectly  to  the  earth.  A  wire 
may  be  insulated  by  being  merely  suspended  in  the  air  at  a  sufficient 
distance  from  other  conductors.  The  required  distance  will  depend 
upon  the  voltage  of  the  current,  a  difference  of  potential  of  10,000  volts 
between  a  wire  and  another  conductor  causing  the  current  to  break 
through  the  insulation  of  about  an  inch  of  air.  Air  insulation  is  good 
enough  for  all  practical  purposes,  and  is  depended  upon  for  telegraph 
wires,  except  at  the  points  where  the  weight  of  the  wire  must  be  sup- 
ported. The  fact  that  the  air  is  a  poor  conductor  of  electricity  and 
may,  therefore,  be  used  as  insulation,  makes  the  installation  and  con- 
struction of  electric  apparatus  much  simpler  than  if  every  wire  and 
switch  and  binding-post  and  screw  had  to  be  protected  from  contact 
with  the  air.  Hare  wires  may  run  in  grooves  in  various  insulating 
materials,  such  as  marble,  slate,  hard  rubber,  or  ivory,  in  stationary 
positions,  where  they  are  not  exposed  to  accidental  contact  with  other 
wires.  The  connections  in  the  ordinary  double-pole  knife-switch  are 
made  in  this  way.  One  wire  from  the  battery  or  dynamo  is  secured  by 
a  binding-post  which  projects  from  the  face  of  the  slate  base.  The 
continuation  of  the  circuit  is  formed  by  a  bare1  wire  laid  in  a  groove  on 
the  back  of  the  slate  or  marble  base  from  the  concealed  end  of  another 
binding-post,  which  carries  the  hinge  at  one  end  of  the  gap.  bridged 
across  by  one  contact  blade1  of  the  knife-switch.  From  this  hinge  the 
current  follows  the  Contact  blade  to  the  contact  jaws,  goes  through  the 
metal  support  to  a  wire  which  passes  along  the  under  side1  of  the  base 
to  be  secured  to  the  concealed  part  of  another  binding-post.  A  wire 
passes  from  this  binding-post  to  the  apparatus.  The  return  current 
follows  a  similar  parallel  path  back  through  the  connections  on  the 
opposite  side  of  the  double  knife-switch.  On  the  under  surface  of  the 
marble  switch-board  of  a  cabinet  for  voltaic  and  faradic  currents  there 
are  sometimes  a  dozen  bare  wires  running  in  grooves  and  forming  the 


'_)-_M  MKDICAI.    KLK<  TKlriTY    AND    H<")NT(iK\     HAYS 

connection  between  the  various  metallic  binding-posts,  switches,  meters, 
ami  resistances  on  the  face  ot  the  switch-hoard. 

The  old  idea  of  tin1  earth  as  a  universal  reservoir  of  electricity  into 
which  either  positive  or  negative  electricity  may  be  allowed  to  escape 
and  will  be  immediately  neutralized  is  quite  a  good  one  as  a  working 
hypothesis.  Take  the  case  of  an  insulated  conductor  like  a  single 
telegraph  wire;  if  one  end  of  the  wire  is  grounded,  and  one 
pole  <>f  tlic  battery  is  grounded  while  the  other  is  connected 
with  the  telegraph  wire,  a  current  will  flow  through  the  battery. 
and  a  meter  which  mav  be  placed  in  the  circuit  and  through  the 
telegraph  wire  and  back  through  the  earth  to  the  other  poll1  of  the 
battery.  The  nature  of  the  transmission  through  the  earth  which 
receives  thousands  of  different  currents  from  natural  and  artificial 
sources  nm.-t  be  very  complicated.  The  hypothesis  which  offers  the 
easiest  explanation  is  that  the  earth  at  any  point  stands  ready  to  supply 
a  deficiency  in  either  positive  or  negative  electricity,  or  to  remove  a 
surplus  of  either  kind.  Demonstrable  currents  of  electricity  are 
iced  in  the  immediate  neighborhood  of  a  grounded  wire,  and  these 
are  tiie  ones  which  destroy  gas-  and  water-pipes  by  electrolysis  in  the 
neighborhood  ni  the  electric  railways.  Leakage  through  the  insulation 
al'>ng  the  telegraph  forms  an  earth  current  which  returns  to  the  battery, 
and  ii  there  i.-  no  other  connection,  the  amount  of  current  passing 
through  the  meter  will  be  simplv  the  amount  of  leakage.  From  Ohm's 


line  i-  found  by  dividing  the  electromotive  force  of  the  bat  terv  in  volts  bv 
the  leakage  current  in  amperes.  The  standard  insulation  resistance  of 
telegraph  lines  i-  'Jon.  I  nil)  ohm-  per  mile.  Km1  instance,  the  electro- 
motive force  from  a  battery  of  I'd  cells  will  send  a  total  current  of 
only  about  ,',,  milliampere  through  all  the  different  slight  leakage 
points  oi  ,-i  milr  ui  t .T 'gra] >h  line. 

'/'A.  //<  .flnnn  »f  (ilnst:  tiiul  I'timlitin  Itiniiltitors.-  Tliis  is  exceedingly 
and  for  elect  fol  herapeut  ic  purposes  these  >ubstaiices  may  be 
regard*  d  a-  absolute  iii  in-ci  inductors. 

II"    /"    ilii/iuti   Hi  xt.<tn IK-I    nf  (;/iff<i-f}<  rfhd.      This   material  is  water- 

pfoot.   ;ii  d    when    not    exposed    to   the  air.    is  verv   durable.       Kxposure  to 

air  and  I  i  LI"  hi  ha-n  n<  oxidat  ion.      \\  ires  in. -ul a  ted  \vit  h  it   and  cout  ained 

I          •  '.-    •' '  -  ibmerged  in  v.  ater  rei      '•     pi  rfecl    for  years.      It   has 

i 

:'•        •        '    •"         'i     -ertloll     helol'e     permanent     e|.  Ullia !  Io)|     takes     place,     and 

.inn  -M'ength  of  :|.")i HI  pounds  per  Hjiiare  inch.  A  gut  ta- 
il '•'  '-'  covering  on  a  wire  adds  :  j.re  than  enough  tensile 
'  a  -  I  wire  to  -U-tain  tin  addition  of  it-  own  weight. 

'  "  "i  tun  la  pi  rd  ;:  \  :  i  i,  :.  M  ,  .,,  deal  with  the 
-'I  times  as  great  at  :\'2  !'.  ;  s  at  7o  :  !-\  The 
•.'  7.")  1  .  of  the  gutta-percha  covering  of  a  mile 

'  '  '  log.       megohms.      Ili-re  D  i-  the  outside  diameter 

mil-    (11.001    inch  I.   and   d    i-   1  he  diameter  of  the 
>"     thai     the     in.-ulation     ivH-latire     in     megohms 

I."""11'1"          !  !     ile  of  glltta-percha-covei'ed  wire   is  e.pial   t"o   jrjl) 

•    the    number    found    by    dividing    I  he    outside 

by  ihi      Lian  eter  o|   t  he  conduct  ing  wire  itself  in  mils. 


DYNAMIC    ELECTRICITY  225 

\\  ires  from  No.  IS  to  Xo.  l(i,  if  insulated  by  gutta-percha  or  rubber, 
which  has  much  the  same  properties,  require  a  coating  at  least  J.,-  incli 
thick,  and  should  have  an  insulation  resistance  of  at  least  100  megohms 
per  mile  at  a  temperature  of  70°  F.  Nos.  15  to  8  require  an  insulation 
/,  inch  thick;  and  Xos.  7  to  2  an  insulation  -,',<-  inch  thick.  These  are 
for  voltages  between  0  and  (iOO.  and  for  electrotherapeutic  purposes 
gutta-percha  and  rubber  may  lie  regarded  as  absolute  non-conductors. 

Tin-  Electrostatic  Capacity  <>J  (rutta-percha  Insulation. — A  wire  with 
an  insulated  wrapping  forms  a  condenser.  The  metal  forms  the  inner 
armature,  the-  gutta-percha  the  dielectric,  and  the  surrounding  sub- 
stances the  outer  armature.  When  an  electromotive  force  is  applied 
to  the  metallic  wire,  the  primary  effect  is  to  charge  this  condenser,  and 
then  later  comes  the  passage  of  a  current  through  the  conductor.  The 
capacity  of  a  condenser  depends  partly  upon  the  size  of  the  two  arma- 
tures, or  outer  and  inner  conducting  coatings,  but  also  to  a  very  great 
extent  upon  the  material,  size,  and  thickness  of  the  dielectric.  The 
dissected  Leyden  jar  (p.  27),  in  which  the  charge  remains  upon  the 
glass  after  both  outer  and  inner  coats  are  removed,  illustrates  this  fact. 
The  electrostatic  capacity  is  from  0.2400  to  0.3945  microfarad  per 
mile.  The  larger  figure  is  in  the  case  of  a  wire  in  which  the  outside 
diameter  of  the  insulation  is  only  2.50  times  the  diameter  of  the  metallic 
wire;  and  the  smaller  figure  is  found  when  the  outside  diameter  is  4.50 
times  the  diameter  of  the  metallic  wire.  The  electrostatic  capacity 
of  a  \vire  limits  the  rapidity  with  which  impulses  can  be  sent  through 
the  wire.  If  the  full  strength  of  the  current  is  suddenly  turned  on, 
there  is  not  an  equally  sudden  impulse  produced  at  each  part  of  the 
line  corresponding  in  time  of  occurrence  to  the  distance  from  the 
generator.  Besides  the  delay  due  to  the  distance  traveled  by  the 
electric  impulse,  at  the  same  rate  as  that  of  light,  about  1S5.000  miles 
a  second,  there  is  a  delay  due  to  the  fact  that  the  condenser  formed  by 
the1  conductor  and  its  dielectric  and  the  surrounding  media  must  be 
fully  charged  before  the  full  strength  of  the  impulse  can  reach  any  distant 
part  of  the  line.  The  result  is  an  impulse  represented  graphically  by  a 
slanting  instead  of  a  perpendicular  line.  The  same  phenomenon  occurs 
when  the  current  is  turned  off.  The  electric  tension  at  any  part  of  the 
wire  does  not  suddenly  subside  at  a  period  of  time  corresponding  to  its 
distance  from  the  generator,  but  subsides  only  gradually  as  the  con- 
denser charge  is  lost.  If  the  successive  impulses  are  too  rapid  compared 
with  the  electrostatic  capacity  of  the  wire,  the  condenser  charge  does 
not  have  time  to  disappear  between  impulses,  and  an  approximately 
constant  current  is  the  result.  In  telegraphy  this  limits  the  number 
of  signals  which  can  be  transmitted  to  those  corresponding  to  135 
words  a  minute.  Wires  used  in  elect  rot  herapeutic  apparatus,  if  of 
sufficient  length  to  possess  an  appreciable  electrostatic  capacity,  are 
almost  always  used  in  the  form  of  coils,  and  in  these  the  effect  of  other 
inductive  influences  overshadows  that  of  the  electrostatic  capacity  of 
the  wire  and  its  insulating  material. 

Tin.'  /WNN  of  }'nxul<ttin</  J'ro/iir/ie*  />//  Marble  and  Hard  Rnblnr.—  It 
will  sometimes  happen  that  a  high-frequency  apparatus  will  cease  to 
work  in  consequence  of  the  fact  that  the  marble  front  or  top  which 
forms  a  base  for  the  binding-posts  leading  from  the  outer  coats  of  the 
Levden  jars  to  the  resonator,  and  for  the  binding-posts  leading  tmm  th<- 
inner  coats  of  the  Leyden  jars  to  the  spark-gap,  has  lost  its  insulating 


-_ti  MKDICAL    KLKCTHICITY    AND    KoNTCKX    HAYS 

properties.     The  commonest  cause  of  this  condition  is  the  absorption 

ot'  moisture  l>y  the  marble,  and  ils  becoming  thus  a  sufficient  conductor 
MI'  electricity  to  allow  the  high-tension  currents  to  pass  along  the  marble 
instead  of  being  compelled  to  cross  the  spark-gap.  This  may  occur 
<pontaneouslv  in  warm  and  moist  climates.  It  may  be  due  to  the 
escape  of  moisture  from  the  I.evden  jars  when  the  latter  are  half  full  of 
some  li(|uid.  like  salt  solution,  forming  t  he  inner  armatures.  The  most 
important  cause  of  absorption  of  moisture  is  found  in  the  nitrous  fumes 
which  are  the  accompaniment  of  discharges  of  high-tension  electricity 
through  the  air.  This  condition  will  occur  even  if  the  Leyden  jars  and 
the  spark-gap  and  resonator  are  entirely  outside  of  the  case  containing 
the  coil.  It  occiii->  without  the  presence  of  a  liquid  in  the  Leyden  jars, 
and  also  with  a  wooden  or  a  hard-rubber  switchboard.  The  marble 
slab  shows  this  condition  to  the  eye,  especially  if  the  surface  is 
unpolished.  It  looks  wet  and  streaked,  and  the  finger  can  rub  off  a 
saltv  or  acid-tasting  deposit.  Prevention  is  better  than  cure  in  such 
a  case,  since  after  the  marble  has  once  become  a  conductor,  it  is  very 
difficult  to  make  it  an  effective  insulator  again.  Four  days'  baking 
will  certainly  drive  out  every  particle  of  moisture  in  the  marble,  but 
will  not  restore  its  insulating  properties. 

It  is  a  good  rule  not  to  use  any  liquid  inside  the  case  of  an  x-ray 
coil  or  high-frequency  apparatus,  and  especially  to  see  that  there  an- 
no imperfect  contacts,  with  their  consequent  sparks  and  nitrous 
fumes. 

It  cannot  vet  be  stated  positively  whether  this  disagreeable  accident 
i-  due  to  ordinary  chemic  processes  entirely,  or  whether  it  is  due  to  a 
process  of  ionixation  of  the  marble  itself,  whereby  it  has  permanently 
acquired  the  property  of  conducting  electricity.  In  the  first  case,  we 
ma\  be  able  to  di-.-ol  ye  out  t  he  disturbing  chemic  compounds  by  soaking 
in  some  solution  and  then  drying  the  marble.  In  the  second  place,  we 
.-hall  have  to  adopt  the  present  plan  of  discarding  a  piece  of  marble 
which  has  once  lierome  a  conductor. 

In  the  case  oi  hard  rubber  the  surface  attracts  moisture  and  dust, 
and  be.-ides  undergoes  a  carbonizing  process  in  the  presence  of  high- 
frequency  eliliivia.  so  that  this  substance  is  not  more  permanent  than 
marble  for  the  purpose  under  consideration. 

'  ila--  may  prove  to  lie  successful  since,  so  far  as  known,  the  changes 

it   undergoes  aftect   onlv  the  -urlace.  causing  a  certain  roughness 

tavors    the   deposit    ot    metallic    nitrate-   and  dust    and    moisture. 

I'-    m.-ulat  iM<_r  qualities   are   probably    restored    bv   washing  the  deposit 

off  the  surface.      Thi-   has  not    been   definitely   settled  yet. 

1  he  peculiar  character  ol    the  current    which   we  have  to  control   in 

Hii-  case  i-  shown  !  r.    l  he  fact   that  a  vivid  white  -park  will  often  be  seen 

at  a  bindinjr-post.      'I  he  screw  may  be  turned  down  as  tight  as  possible, 

and  -till  the  thin  film  of  o\id  between  the  two  metal  surfaces  will  offer 

deuce  to  cause  the  current    to  leap  across  an  air-space  of 

1    '  ract  ion   i  if  a  n    inch. 

\  lightning  arrester  i-  always  required  when  wires  enter  a  building 

above    ground.       It     i-    an    arrangement     lor    leading    a    charge    of    high- 

tension  atmo.-pheric  electricity  to  the  ground,   instead  of  allowing  the 

pa--    into    the    hoii-e    along    the    wires,    with    danger    to    the 

and    occupants.      The   general    principle   j-   to   have 

dated   \\ire,  a-   ln-;ivv   as   \o.   Hi.  thoroughly  well    grounded,  and 


DYNAMIC    ELECTRICITY 


227 


terminating  in  a  metal  plate  with  saw  teeth  supported  upon  the  same 
insulated  base,  with  a  similar  metal  plate  which  forms  part  of  the 
electric  supply  circuit.  The  sharp  points  of  the  two  plates  an;  bare, 
and  only  a  fraction  of  an  inch  apart,  but  normally  none  of  the  current 
will  leave  the  electric  circuit  and  leap  across  the  non-conduct  ing  air- 
gap  between  the  two  sets  of  points.  The  high-tension  charge  of  atmos- 
pheric electricity,  however,  with  its  enormously  high  frequency  (millions 
of  oscillations  a  second),  flashes  across  this  space  and  is  safely  led  to 


Fig.   Kid. — Westillghouse  electrolytic  lightning  arrester. 

earth.  It  is  true  that  the  ohmic  resistance  of  the  air- 
gap  is  infinitely  greater  than  that  of  the  win's  in  the 
various  instruments,  but  the  high  tension  makes  it 
possible  for  the  atmospheric  electricity  to  overcome 
this  resistance.  Currents  of  extremely  high  voltage 
and  extremely  rapid  oscillations  are1  subject  to  an  in- 
ductive1 impedence  which  will  cause1  them  to  leap  a 
considerable  air-space  and  follow  the  shortest  path 
rather  than  follow  a  long  conducting  path,  even  though 
the  latter  has  ample  carrying  capacity.  Another  form 
of  lightning  arrest eM1  is  made1  by  wrapping  half  a  elo/e'n 
turns  of  insulate1*!  wire1  aremnel  the  elect rie'-light  wire1  before  it  enteTs  the1 
house1.  The1  other  end  of  this  insulated  wire1  is  grounded,  as  in  the1  first 
type1  of  lightning  arrester,  by  being  solelered  to  a  metal  water-pipe  or 
to  a  mass  of  iron  buried  in  a  pit  filled  with  dam])  charcoal. 

fclcctroliitic  Liijhtm'mj  J/'/TN/rrx. —  These1  afford  a  short  chvuit  for 
the  cunvnt  wheneveT  it  becomes  of  a  sufficiently  high  voltage1  to  over- 
come  the1  resistance1  of  the1  liquid.  The1  resistance1  can  be  so  delicately 
adjusted  that  e'ven  a  small  percentage  of  increase'  over  the1  ordinary 
operating  voltage1  will  be1  prevented  from  passing  into  the  house  circuit 
(Fig.  1  tid").  The'  principle'  is  the  >anie  as  in  the  familial1  electrolytic 
interrupters  used  with  .r-ray  coils. 


c.         r. 

too                      j/j. 

^/o      ' 

Zoo 

so 

190 

SO 

/So 

'7o 

70 

J60 

/fo 

(,0 

/4-o 

'3 

f» 

'3.0 

I/a 

+0 

too 

fo 

-*- 

ao 

20 

7o 

to 

to 

SO 

4o 

o 

24 

3.0 

-10 

10 

o 

-20 

-/o  

Fig.   167.—  C 

igrade    a  ul    1'a 
•illicit    thennon 
•ic  scales. 

en 
hr 
et 

22S  MF.niCAI.    KI.KtTKiriTY    AND     KONTCKN    RAYS 

YAU'KS  OF   KNCI.ISH   AM)   MKTR1C   MKASTHES. 

One  meter  =  :i  LNd'i  feet  =--- 3«t.:*7  inches. 

One  centimeter  _o.:Wo7  incli.  or  about    ,'',,  inch. 

One  millimeter    0.001   meter    ^().do<i:>7  inch,  or  about   ,,';,  inch. 

One  kilometer     1  (MM)  meters    =  about    ^  mile. 

(Mir  t;ram      l.l.lo'J  i;raiu-  .Tn>y  . 

On,'  kilojrram     UMMI  Lnvim-       -  .Jit  pounds  Avoirdupois. 

<  )ne  cubic  centimeter     1  c.o.1  ^O.Oiilo:;  cubic  inch. 

One  liter    KM  Ml  c.c.  >     ill  .(>:!  cubic  inches  -=().Ns()4  quart. 

(  die  decree  (  Vlltiirrade  =  '-,   decree    Fahrenheit. 

(I    (Vntmrade     :;_'     l-'ahrenheit      free/inu-point  of  water. 
KM)    < 'entiiirade     '-'1'-'     1  -'ahrenlieit  =-  boiling-point  of  water. 
Idd     Fahrenheit          :',7>    ('. 

:'.'.'    Fahrenheit  =  :'.>    ( '.  --  maximum  density  of  \vater. 

ild-  Fahrenheit  =  l.").."r"  C.  =  temperature  at  which  electric  resistances  are 
USUallv  measured. 

MEASUREMENTS  OF  RESISTANCE 

Different  substances  have  specific  conductivities,  and  a  conducting 
path  consist  ing  "f  a  i:iven  length  and  area  of  cross-section  will  present 
a  resistance  which  may  be  calculated  by  reference  to  a  printed  table. 
Any  change  in  cheinic  composition  <»r  in  temperature  or  other  conditions 
produce.-  a  change  in  electric  resistance.  This  fact  is  illustrated  in  the 
most  wonderful  manner  by  the  conductivity  of  water  and  aqueous 
solutions,  especially  of  acids  and  salts.  Taking  the  conductivity  of 


a  solution  of  sulphuric  acid  one  to  six  of  water,  has  a  conductivity  about 
loofKXMHH)  1'1:i1  "'  >''V('r-  'I'l'i*  is  ''"'  solution  which  is  used  as  the 
electrolyte  in  the  liquid  interrupter  for  .r-ray  coils.  The  smallest 
admixture  of  any  other  .-ubst atice  multiplies  the  conductivity  of  water 
to  a  perfectly  enormous  extent.  The  electric  resistance  of  a  disk  of 
pure  water  1  millimeter  thick  is  as  <ireat  as  that  of  a  rod  of  silver  of  the 
same  cro-s-sect ion.  but  twice  as  lonsr  as  the  distance  from  the  earth  to 
the  moon.  One  electric  resistance  which  has  to  be  tested  in  elect ro- 
therapv  i>  that  of  the  insulation  in  different  parts  of  the  apparatus  and 
in  the  covennu:  oi  the  wires.  Another  is  the  internal  resistance  of  the 
battery.  These  two  tests  are  sufficiently  described  on  pp.  90  and  229 
ier  is  the  resistance  of  the  wires  themselves,  while  others  are  those 
oi  the  li\  mi:  tissues,  especially  the  skin,  which  is  highly  resistant,  and 
tin  resistance  o'  physiologic  tluid>.  such  as  the  urine  and  blood. 

Testing  Resistance  by  Simple  Substitution.  —An  unknown 
!•••-:-•  a'M-e.  |;.  i<  connected  iii  series  \\ith  a  constant  batterv  and  a 
[galvanometer,  (i.  and  the  current  strength  is  noted.  Then  a  standard 
resistance,  1;'.  -ubstituted  for  the  unknown  resistance,  and  is  varied 

until    the    Lr:u'   aliometef   shows    Thai     the    curi'etll     SlrelltTtll    is    I  lie   same    as 
111    I  lie    Jir-t     Itlst  atice.  1'hen     1  ,'          I  !  '. 

I'   ma\    not  always  he  practicable  to  vary  the  standard  resistance  so 
a.~  i"  make  the  current  equal  to  the  one  to  be  tested,  and  in  that  case  a 
1    i-  '   •  be  n  ade.  i  .ase,]  upon  t  he  relal  ive  si  re  n  ill  li  of  the  current 
-.',  it  h  t:i<    two  d  it'f  e  rent   resistances.      If  ,/  j^  the  deflection  obt  ained  with 
the     n  •     resist  ..me!-,   and   '/'.that   nblained    wit  h  t  he  -l  andard  resist  - 

ance.   and    (>    i-  'he   '-.'-i-tance    oi     the  iialvaiiomet er   (it    i>  necessary  to 
kiio\\    •  md    ••,(•    internal    resistance   oi    the    balterv    is   so   small    in 


DYNAMIC'    ELECTRICITY  229 

The  standard  resistances  used  in  the  foregoing  tests  are  obtained  by 
the  use  of  a  resistance  box. 

It  is  necessary  to  take  precautions  to  secure  joints  as  free  from 
resistance  as  possible  or  the  results  will  be  vitiated.  The  ends  of  the 
wires  should  be  scraped  free  from  oxid  or  grease,  and  where  delicate 
measurements  are  attempted,  the  different  contacts  should  be  made  by 
dipping  the  ends  of  the  two  wires  into  the  .same  cup  of  mercury. 

Measuring  Resistance  With  a  Voltmeter. — The  apparatus  required 
are  a  standard  resistance,  any  source  of  electricity,  and  a  voltmeter. 
First,  with  the  current  passing  through  the  standard  resistance,  the 
voltmeter  reads  X,  showing  a  voltage  drop  of  X,  or  a  difference  of  X 
volts  between  the  two  terminals  of  the  known  resistance.  Then  the 
same  test  applied  to  the  unknown  resistance  shows  a  voltage  drop  of  Y. 
The  resistances  are  inversely  proportional  to  the  voltage  drops. 

Measuring  Resistance  by  Difference  in  Potential. — This  is  a  method 
which  is  delicate  enough  for  testing  the  resistance  even  of  short  lengths 
of  wire.  It  depends  upon  the  fact  that  there  is  a  difference  in  poten- 
tial between  any  two  points  of  an  electric  circuit.  And  if  two  sepa- 
rate sets  of  points  are  tested  along  the  same  circuit,  the  two  differ- 
ences in  potential  will  be  directly  proportional  to  the  resistance  in  the 
portions  of  the  circuit  between  one  pair  of  points  and  the  resistance  be- 
tween the  other  pair.  Figure  168  shows  the  arrangement  of  an  apparatus 


K 
Fig.    168. — Measuring  resistance  by  testing  difference  in  potential. 

for  making  this  test.  G  is  a  sensitive1  galvanometer,  a  mirror  galvano- 
meter, for  example,  with  a  high  resistance  as  compared  with  the  resist- 
ance which  is  to  be  tested.  K  is  a  constant  current  battery,  such  as 
several  Daniell  cells,  and  K  is  a  key  by  means  of  which  the  circuit  is 
closed  or  opened.  R~  is  the  resistance  to  be  measured,  and  the  con- 
nection at  either  end  may  be  made  us  in  the  diagram,  by  means  of  a 
mercury  cup,  or  the  Avire  may  be  soldered  to  the  other  wires.  R'  is  a 
standard  variable  resistance1,  such  as  a  100  cm.  of  German-silver  wire 
of  a  certain  size,  with  a  known  resistance  per  centimeter.  There  is  a 
very  perfect  electric  connection  between  the  two  resistances.  A  double 
pole  switch,  not  shown  in  the  diagram,  makes  either  the  connection 
shown  by  the  heavy  lines  in  the  diagram,  or  that  shown  by  the  dotted 
lines.  In  the  former  case  the  galvanometer  is  in  shunt  to  the  standard 
resistance  R'.  and  in  the  latter  case  to  the  unknown  resistance  R2. 
R1  is  to  be  varied  until,  as  we  turn  the  switch,  making  alternately  one 
connection  and  then  the  other,  the  same  amount  of  deflection  is  pro- 
duced. Then  R-  -•-•  R'.  In  other  words,  the  resistance  utilized  at  R' 
indicates  exactly  the  resistance  of  the  object  which  was  to  be  tested. 
The  adjustment  may  be  made  by  varying  the  length  of  the  wire  which 
is  to  be  tested  if  it  is  a  wire,  and  in  such  shape  that  a  sliding  contact 
mav  be  had  with  it.  The  original  100  cm.  of  the  standard  resistance 


230 


MKDK'AL    ELKCTRICITY    AM)    KoNTCKN    RAYS 


wire  is  unvaried,  and  we  find  how  many  inches  of  the  unknown  wire 
have  a  resistance1  equal  to  that  of  100  inches  of  the  standard  wire. 
From  this  it  is  easy  to  calculate  the  resistance  in  ohms  of  any  desired 
length  of  the  wire  under  test. 

This  method,  l>y  means  of  comparative  difference  in  potential,  is 
adapted  to  measuring  the  resistance  of  a  short  wire,  or  such  a  resistance 
as  occur-  at  the  contact  between  the  brushes  and  the  commutator  section 
in  a  motor  or  a  dynamo. 

Generally  speaking,  the  resistance  of  different  physiologic  tissues 
and  fluids  is  so  great  as  not  to  be  conveniently  measured  by  this  method. 
Measurement  of  Resistance  by  Direct  Application  of  Ohm's  Law. — 
With  any  suitable  source  of  potential,  an  amperemeter  in  series  with 
the  resistance  to  be  tested  and  a  very  high  resistance  voltmeter  in 
shunt  to  the  resistance  to  be  tested.  By  Ohm's  law  the  unknown 
resistance  is  equal  to  the  voltage  divided  by  the  amperage. 

Measurement  of  Resistance  by  Wheatstone's  Bridge. — This  is 
on  a  very  similar  principle  to  that  of  the  measurement  of  the  electro- 
motive force  by  Lumsden's  method  of  opposed  electromotive  forces. 
The  diagram  (Fig.  1(>(.)>  shows  the  general  arrangement.  One  of  the 
wires  from  a  constant  current  battery,  K,  divides  into  two  paths,  A  and 
H.  havimr  fixed  resistances.  The  other  wire  from  the  battery  divides 
into  two  paths,  one  of  which  -is  a  variable  standard  resistance,  K1:  and 
nwn  resistance.  II-.  which  is  to  be  measured.  A 
to  a  wire  ln>m  H1  at  the  point  I  in  the  diagram. 
and  a  wire  from  H  to  one  from  R2 
at  '2.  Between  the  points  1  and  2  is 
a  cross  wire  with  a  galvanometer,  G. 
The  current  being  turned  on,  there 
will  be  an  electromotive  force  at  1, 
tending  to  send  a  current  through  the 
galvanometer  toward  2;  and  at  2 
there  will  be  an  electromotive  force 
'ing  to  send  a  current  toward  1. 
fixed  resistances  and  the  vari- 
able standard  resistance  are  regu- 
lated with  reference  to  the  resist- 
ance to  be  measured,  so  that  the 
galvanometer  -hows  no  deflection. 
\\hen  this  is  the  case,  it  is  capable 
ot  demonstration  that  the  following 

U  :  :  R1  :  It2. 
sides  of  the 


\ 


• 


M 


ften, 


lire  are  en 


nit;  Its  re-i.-t  aiice  until  the  galvanometi 
i   multiplying  the  value  of  I!1  by  Id.  Kill,  or  K )()(),  as  the  case  may  be. 
tli''  other  li;m«l.  the  unknown  resistance  may  be  so  -mall  that  it  will 
make  A    in.    Kill,  01-   KMMI  times  the  value  of  I',.      In  that 
mid   the   value  of   IJ1.   this   value   is   to  be  divided   by    10, 
if   I!     bears   the  same   relation   to    ]>'   that    P>  bear-  to  \-\. 
r  condition    may   occur.      It    may   not    be   practicable  to 
\act    balance,    shown    by    the    ab-ence    of   deflection    in    the 


DYNAMIC    ELECTRICITY 


231 


galvanometer.  The  amounts  of  deflection  with  the  nearest  available 
values  of  R2  above  and  below  the  true  value  form  the  basis  for  the 
calculation  of  the  small  fraction  to  be  added  to  or  subtracted  from  the 
nearest  available  trial  resistance. 

The  electric  bridge  or  balance  is  made  up  in  different  forms,  and  in 
some  there  is  a  slight  modification  of  the  theoretic  combination  of  parts, 
but  they  all  depend  upon  the  same  principle':  that  equal  opposed  electro- 
motive forces  produce  no  deflection  in  a  galvanometer.  The  equality 


Fiji.  170. — Drop  in  potential  along  a  uniform  resistance  proportional  to  distance  between 
two  poles  of  a  battery.      The  Wheatstone  bridge  equivalent. 

of  the  electromotive  forces  at  the  points  from  which  the  galvanometer 
circuit  is  derived  may  be  illustrated  by  the  diagrams  (Figs.  1(59  and  170). 
Figure  170  shows  a  difference  of  five  volts  in  potential  between  the 
point  marked  Cu-f-  at  the  positive  end  of  the  bridge,  and  the  point 
marked  Zn  —  at  the  negative  end  of  the  bridge.  Representing  electro- 
motive force  as  height,  we  should  have  Zn—  at  the  zero  level,  and  Cu-f- 
at  a  height  of  five  units  (representing  ohms).  The  line  joining  these 
two  points  represents  resistance,  and  the  point  P  has  50  ohms  between 


i#.  171. — Another  example  of  the  conditions  in  Fig.  !(>!) 


it  and  Zn  — ,  and  1200  ohms  between  it  and  Cu  — .  In  other  words, 
P  is  a  point  along  the  circuit  separated  from  Zn  —  by  only  one-twenty- 
fifth  as  much  resistance  as  there  is  between  ( 'u  —  and  Zn--.  According 
to  very  well-established  principles,  the  difference  in  potential  between 
P  and  Zn  is  only  one-t  wenty-fift  li  as  much  as  that  between  Cu  —  and 
Zn  — .  The  electromotive1  force1  at  P  is,  therefore,  correctly  represented 
by  a  height  of  0.2  unit  (equivalent  to  0.2  volt). 


2'.}'2  MKDH'AL    KLKriKKITY    AND    KOXTUEN     KAYS 

Turnim:  now  to  Fig.  171.  we  find  the  same  potential  at  Cu+  'five 
volts)  and  that  the  resiMance  l»et\veen  I"  and  Zn—  (200  ohms)  is 
one-twenty-tifth  that  of  Cu  +  <>r  <*•-  ohm. 

There 'is  the  siine  potential  at  1*  and  I"  when  the  four  resistances 
hear  the  proper  relation-  to  each  other,  and  having  the  same  potential 
no  tlow  of  current  occurs  between  P  and  1". 


Fig.  172. — Student's  resistance  box. 

The  Resistance  Box.— The  fixed  and  variable  resistances  employed 
in  te-tim:  electromotive  force  or  resistance  are  usually  obtained  from 
a  h"X  con: ainim:  several  coils  of  wire  having  different  standard  resist- 
ances  varying  from  0.1  ohm  to  perhaps  10. 000  ohms.  In  some  cast's, 
the  different  resistances  are  introduced  into  the  circuit  by  pushing  a 

pliiii  into  a  hole,  and  in  other  cases  it  is  by 
pulling  a  ])lu.<£  out  of  a  hole,  and  in  still  other 
cases  'here  an-  sliding  contacts  by  which  the 
resistance  is  changed.  These  resistance 
coils,  of  course,  have  a  tendency  to  heat  up, 
but  this  is  not  dangerous,  because  the  current 
i>  usually  a  small  one  obtained  from  a  few 
l)amcll  cells  and  measured  in  milliamperes 
rather  than  in  amperes,  and  it  is  turned  oil 
A  resistance  coil  of  looo  ohms  miiiht  consist  of 


DYNAMIC    ELECTRICITY 


The  resistance  of  German  silver  wire  is  about  l^.o  times  that  of 
copper  wire  of  the  same  size. 

Electric  Conductivity  of  Solids. — Metals  and  other  good  conduc- 
tors transmit  the  current  without  evident  change  in  their  physical  or 
cliemic  constitution,  and  at  the1  same  velocity  as  that  of  light.  All  sub- 
stances, however,  present  <ome  resistance,  develop  some  change  in 
temperature,  and  undergo  some  chemic  change. 

CondKcthuj  *sYm'.s. — The  substances  are  arranged  in  the  order  of 
their  conductivity: 


Silver 

( 'upper 

Cold 

Zinc 

Plat  inum 

Iron  

Tin    

Lead 

Mercury 

( 'liarcoal  and  coke 

Acids 

Saline  solution.  .  .  . 

Sea-water . 

Water 

The  body 

Cotton 

1  )ry  wood 
Marble 


Ciood  conductors. 


i   Sometimes  classed  as  conductors, 
[        sometimes  us  semiconductors. 


Partial  or  semiconductors 


Testing  the  Resistance  of  a  Galvanometer. — If  another  galvanom- 
eter  is  available,  the  Wheat-stone  bridge  is  used.  The1  galvanometer 
whose  resistance  is  to  be  tested  is  placed  in  the  position  of  11-  in  the 
diagram  (Fig.  1(>9),  and  the  other  galvanometer  in  the  cross  circuit  of 
the  bridge.  The  resistance  of  the  unknown  galvanometer  with  or  with- 
out a  shunt  is  then  tested  as  if  it  were  any  other  resistance. 

Thomson's  (Lord  Kayleigh's)  mctlnxl  is  useful  when  there  is  no  other 
galvanometer  available.  A  Wheatstone  bridge  is  used  (Fig.  174),  and 
the  galvanometer  to  be  tested  is  placed  in  the  ordinary  position  of  the 
unknown  resistance.  At  the  place  upon  the  cross  circuit  where  a 
galvanometer  is  ordinarily  placed  there  is  none,  but  instead  there  i-  a 
key  for  opening  and  closing  this  cross  circuit.  A  and  B  are  fixed 
resistances,  and  H1  is  varied  until  the  deflection  shown  by  the  »a!- 
vanometer  is  the  same  whether  the  cross  circuit  is  closed  or  open. 


234 


MEDICAL    ELKrTHICITY    AND    RONTGEN    KAYS 


Then  A  R1      B  (I  and  (i  -K1 


This  method  has  the  advantage  tha: 


it  is  independent  of  the  internal  resistance  of  the  battery.  One  wire 
from  the  battery  should  £0  to  the  junction  between  the  two  lowest 
resistances,  and  the  other  wire  to  the  junction  between  the  two  highest 
resistances. 

To  Measure  the  Internal  Resist- 
ance of  a.  Battery. — The  simplest 
and  readiest  method  is  illustrated 
in  Figs.  175  and  176.  The  battery 
has  two  short  heavy  copper  wires, 
and  the  galvanometer  is  shunted  by 
a  short  thick  copper  wire,  so  that 
the  resistance  of  the  conducting  cords 

(is          .       .    . 
and-  --,   the  joint    resistance   of 

Lr  +  S 

the  galvanometer  and  its  shunt,  may 
be  neglected.  These  resistances  are 
to  be  very  small  in  comparison  with 
the  internal  resistance  of  the  battery. 
The  current  is  turned  on.  and  the  deflection  of  the  galvanometer  is 
noted.  Then  a  resistance  is  introduced  at  R.  and  is  varied  until  the 
galvanometer  indicates  only  half  as  strong  a  current  as  before.  Since1 
the  current  is  onlv  half  as  strong,  the  resistance  must  have  been 
doubled.  Therefore  /•  (the  battery  resistance)  -fll  =  '2  r.  And/'  =  R. 


I7.r>  ;IIH]  17»).    -  Mc:i.-uriiiK  internal  resistance  of  a  battery. 


Another  -imple  method  is  described  on  page  5)0. 

Testing  Electrostatic  Capacity.     The  static  charge  on  an  insulated 
ductor  may  be  measured  by  discharging  it   through  a  ballistic  gal- 
ometer.     The  latter  is  any  galvanometer  in  which  the  movable  part 
eavy  enough  to  cause  a  series  of  pendulum  oscillations  in  consequence 
•''    momentary   di-<-harge.      Such   an    instrument    must    be   graduated 
experiment   with  -tandard  quantities  of  electricity,  and  this  is  done 
di-chartring  known  capacities  charged  to  known  potentials  through  it. 
Measurement    of    Electric    Capacity.     This    may    be    done    by 
ruing  the  bod',  to  a  known  potential,  and  then  measuring  the  amount 
electricity  by  discharging  i'  through  a  ballistic  galvanometer.1 
A  certain  amount  of  electricity  may  charire  a  body  of  large  capacity 
•'>  low  potential,  and   have  very  different   properties  (notably  in  that 
roduces  no  noise  or  -hock  when  di<charured )  from  that  of  the  same 


DYNAMIC    ELECTRICITY  23:") 

amount    of  electricity  charging  a   body  of  .small   capacity   to   a   high 
potential. 

The  difference  may  be  likened  to  that  between  the  same;  amount  o; 
heat  which,  when  absorbed  by  a  pint  of  water,  will  not  warm  it  per 
ceptibly.  but  it  applied  to  a  needle,  will  make  it  red  hot  and  capable  of 
searing  the  flesh. 

Condensers.  —  Leyden  jars  and  the  many-leaved  condensers  ot 
induction  coils  have  a  definite  capacity  which  depends  partly  upon  the 
nature,  size,  and  thickness  of  the  armatures  and  of  the  dielectric  .sepa- 
rating them.  Every  object,  solid,  liquid,  or  gas,  which  can  receive  an 
electric  charge  has  a  certain  capacity,  and  exhibits  the  properties  of  a 
condenser  to  a  greater  or  less  extent  according  to  circumstances.  A 
submarine  cable,  for  instance,  has  a  large  electrostatic  capacity  which 
shows  itself  in  two  ways:  first,  it  takes  an  appreciable  amount  of  elec- 
tricity and  a  certain  length  of  time  to  charge  it  to  such  an  extent  that 
it  begins  to  act  as  a  conductor  and  deliver  current  at  the  other  end. 
Second,  when  the  current  is  turned  off,  the  cable  has  a  certain  charge 
which  causes  it  to  continue  to  yield  a  current  for  a  certain  time.  The 
currents  through  the  cable  do  not,  therefore,  begin  and  end  with  the 
sharp  click  of  the  transmitter,  and  the  rapidity  with  which  signals  can 
be  sent  through  it  is  limited.  Coils  of  insulated  wire  are  used  as  capaci- 
ties in  connection  with  certain  electric  transformers.  Leyden  jars  are 
usually  charged  with  very  high-tension  electricity,  generated  by  a 
static  machine,  and  receive,  therefore,  a  magnitude  of  charge  which 
is  quite  wonderful  when  the  small  capacity  of  the  jar  is  considered. 
The  Leyden  jar  or  some  equivalent  thereof  with  a  perfect  and  practically 
indestructible  dielectric  is  the  type  of  condenser  that  must  be  used  for 
charges  of  very  high  potential.  The  capacity  may  be  increased  by 
using  a  larger  Leyden  jar  or  connecting  a  number  of  Leyden  jars  and 
charging  them  all  at  the  same  time.  There  are  two  principles  upon 
which  Leyden  jars  may  be  connected.  They  may  be  connected  in 
parallel,  all  the  inner  armatures  being  connected  to  form  one  pole,  and 
all  the  outer  armatures  connected  to  form  the  other  pole.  The  capacity 
of  the  condenser  thus  produced  is  equal  to  the  sum  of  the  capacities  of 
the  individual  Leyden  jars.  The  other  way  is  to  connect  the  inner 
armatures  of  one  jar  with  the  outer  armature  of  the  next,  and  the  inner 
armature  of  that  with  the  outer  armature  of  the  next,  and  so  on.  This 
is  called  a  series  connection,  and  the  two  poles  of  such  a  condenser  are 
formed  by  the  outer  armature  of  the  jar  at  one  end  of  the  series,  and  the 
inner  armature  of  the  jar  at  the  other  end  of  the  series.  This  is  an 
arrangement  similar  to  that  in  which  Leyden  jars  are  charged  by 
cascade.  The  capacity  of  a  condenser  made  up  in  this  way  is  equal  to 
the  reciprocal  of  the  sum  of  the  reciprocals  of  the  capacities  of  the 
individual  Leden  ars— 


A  Leyden  jar  with  a  total  coated  surface  of  1  square  meter  and  with 
glass  1  millimeter  thick  has  a  capacity  of  J--  microfarad.  The  capacity 
of  the  Leyden  jars  used  in  high-frequency  apparatus  is  about  O.OOl^ 
microfarad,  of  three  such  Leyden  jars  connected  in  series  the  capacity 
would  be— 


230 


MKDH  AI,    KLKCTKK'ITY    AM>    KOXTliKX     HAYS 

1  0.00  IS 


I  1  :; 

O.OOhS  (I. IIDlS      '      0.00  IS  OOOlb 


=    0.0001)  microfarad. 


Ttxliini  tin'  Cn /xicili/  ni'  a  Condenser  />//  Direct  DixcJmrgc. — This  is  a 
.-imple  method  which  vields  approximate  results.  It  requires  the  use 
(if  a  mirror  galvanometer  or  a  sensitive  astatic  galvanometer,  and  of  a 
.-tandard  condenser  ot'  known  capacity.  (',.  A  standard  condenser 
•  Fiir.  1771  is  a  necessarv  pail  of  anv  outfit  for  making  tests  of  electric 


Kit:.  1(7. — Standard  condenser. 

capacity.  Snr-h  n  standard  capacity  of  ^  microfarad  may  contain 
1'Ji n i  xjiiare  inches  of  tin-foil  in  small  sheets  separated  by  paraffin 
paper.  The  same  bat  tery  is  used  to  charge  first  the  standard  condenser, 
and  1  hen  i  he  condenser  whose  capacit y  is  to  be  measured.  The  standard 
•ondenser  is  discharged  through  the  galvanometer,  and  the  amount  of 
defied  ion,  d,,  is  noted.  'I' hen  1  he  condenser  with  an  unknown  capacity, 
('.  i-  discharged  through  the  galvanometer,  and  its  deflection,  d2, 
i.-  noted.  Then 

r,      :      C,     :  :     d,      :     ,1, 


7  >•!,,,: .-.,.(,'.•  i  /,',:  //,  it//,'.-')  M<  /find  of  Ten/ing  fJie  Cfipaeitft  of  Condensers 
mat  Cniidiictni:--.-  The  capacity  to  be  tested  for  elect  rot  herapen  tic 
purpo;-es  i:,;:-.  In-  that  of  the  secondary  winding  of  an  .r-ray  coil  or 
er. 

7 /•'  A  f>i>tirtifn.--  ff(ffnii-(d  (Fig.  ITS). — P>  is  a  battery  of  about  ten 
Daniel!  01  other  coji.-taiil  voltaic  cells.  This  must  be  well  insulated 
from  the  gfounrl,  M<  \ve)]  as  between  its  two  opposite  charges. 

A '  /'  is  a  l.i  \  '  e;ms  of  whicli  the  circuit  is  made  or  broken  close 
to  one  pole  of  t  he  !  i;it  t , 

A'  r  is  n  key  by  the  circuit  is  made  or  broken  between  the 

battery,  and  one  end  o!  the  coil  of  wire  whose  capacity  i.s  to  l)e  tested. 
The  ial  t'-;  i.-  marked  ,  ,,'/. 


DYNAMIC      ELECTRICITY 


Coil  in  the  diagram  has  the  other  end  of  its  wire  free. 

C2    is  the  capacity  of  the  coil  expressed  in  microfarads. 

AY//:i  makes  or  breaks  the  circuit  at  the  point  where  a  wire  lends 
from  the  battery  to  one  electrode  of  the  standard  condenser,  whose 
capacity  is  C'1  expressed  in  microfarads,  and  whose  other  electrode  is 
grounded. 

From  a  point  between  the  battery  and  the  standard  condenser  a 
side  line  crosses  to  the  earth  through  R1,  which  is  a  variable  resistance. 

From  a  similar  point  on  the  cir- 
cuit from  the  battery  to  the  coil  a 
side  line  passes  to  earth  through  R2. 
which  is  a  fixed  resistance. 

(!,  the  galvanometer,  is  on  a 
line  connected  at  one  end  with  the 
junction  of  these  two  resistances,  at 
the  point  where  they  are  fastened  to 
a  ground  wire,  and  at  the  other  end 
with  the  circuit  between  the  standard 
condenser  and  the  coil.  o^^d 

AY//-"'  makes  and  breaks  the  gal-  Fi«.  178.— Testing  the  capacity  of  a  coil. 
vanometer  circuit. 

The  test  is  made  ax  folio irx:  1.  Close  Av//1,  then  V1  and  V2  may  be 
the  potentials  at  the  points  of  junction  of  the  battery  wires  with 
the  resistances  R1  and  R2  leading  to  earth.  The  current  is  the  same 
through  the  battery  and  through  both  resistances,  since  these  are  in 
series.  The  voltage,  therefore,  must  be  proportional  to  the  resistance, 
and  we  have — 

V1     :     V2     :  :      R1     :      R-'. 

2.  While  Av//1  i§  still  closed,  close  Av//2  and  Av//:!  simultaneously 
for  a  fixed  time,  charging  both  the  capacities.  The  standard  con- 
denser C1  is  charged  to  a  potential  of  V.  while  the  capacity  C2  to  be 
measured  is  charged  to  a  potential  of  V2. 

A'//-"'  and  Av//1  which  lead  from  the  free  extremity  of  the  coil  to  the 
condenser,  have  been  open  during  th.'s  time,  and  the  proximal  electrode 
of  the  standard  condenser  has  been  connected  only  with  the  negative 
pole  of  the  battery.  The  capacity  to  be  measured  has  been  connected 
only  with  the  positive  pole  of  the  battery.  The  proximal  armature 
of  the  standard  condenser  and  the  capacity  to  be  measured  are.  there- 
fore, charge*  1  with  negative  and  positive  electricity  respectively. 

The  quantity  of  negative  electricity  received  by  C'  H  Q1  Y'C1. 
while  the  amount  of  positive  electricity  received  by  C2  is  (,)-  \ -('-'. 

o.  Open  Av//'  and  Av//:!.  cutting  off  all  connection  with  the  battery. 
Close  Av//'1.  allowing  the  positive  and  negative  charges  of  C2  and  C1  to 
mix.  Their  potentials  are.  of  course,  immediately  equalized,  and  if  the 
quantities  are  equal,  both  charges  are  neutralized.  Open  Av//'  to  test 
this.  The  occurrence  of  a  deflection  indicates  an  excess  either  ot 
positive  or  negative  electricity  in  the  combined  capacities,  and  another 
trial  must  be  made  with  another  value,  to  the  variable  resistance  I!1. 
Tin's  is  repeated  until  a  complete  equality  and  neutralization  of  the 
charges  in  the  two  capacities  are  indicated  bv  the  absence  of  deflection 
in  the  galvanometer.  We  now  have  the  factors  for  the  calculation  oi 
the  unknown  resistance.  These  factors  are  the  resistances  of  the  two 


JliS  MI.DK  AI.    I.I.i:(   1  UK  II  1     AND    KOXTOKN    HAYS 

,.;  ;•';.  >hunts  determining  tlir  voltages  required  to  charge  the  standard 
.  ilic    iiiikiu'\vii  capacity  \viili  the  same  quantity  <>i  elee- 
.      Vn  •  h  d  ric  capacity  i.-  like  a  compressed  air-tank  -  just  so  much 
H    forced  into  it  ami  will  completely  till  or  charge  il  at  a 
,  »ure;   !'ii'    t'mir  times  as  much  can  he  lorced    in    and   will   he 
-e    it    at    twice    that    pressure.        \o   less   amount 
I  produci    t  he  specified  pressure  in  the  condenser. 
['he  i<  >lli  'wint:  i-  1  he  calculal  ion  : 

\     t         \" •'('-'.       ['he    i|Uaiitities    of   electricity   in  the  two    capacities 
.    ,,;.'..       And   from   this  the  following  proportion   is  obtained: 


n  mat    - 

V-     :      V      :  :      R-     :      !{'. 

i;2      :      K'      :  :     ( ''      :     ( "-'.   Mini  t'rmn  tl 

/    •  . 


There   is  re  niher  methods  of  measuring  the  capacity  of  condensers 
IT  i     •    .  .   •    :-.  h  it   this  one  is  accurate  and  readily  available  for  lab»ra- 

•  .. 

\   -ei    n|    Leydell   jars  of  eijual   capacity   connecteil   in   jiarallel   has  a 

iv   fnimd   l>y   multiplying  the  capacity  of  one   I.eyden 

':.'    numher  of  jar.-.      '1  he  same  jars  connected   m  .-cries  have  a 

,:,'    ;  •:••'•.'•.  which  is  found  1  iy  dividing  the  capacit  \"  of  one  jar 

(>:  n-i    dii'fi  ri  :.'    ci  ml iinat ions   may    I"1    made   corri'sjKindinii  to   the 

---•:.—    alni    -erie--mull  ijile    arrangement     of    voltaic    cells    in    a 

\>  .''']•..      The.-i'  inve  anv  de.-irei  1  capacit  v,  lai'u'e  or  small,   if  t  here  are 

M  r    o|     Ley i  Icn    jar.-    a\'allal  ile. 

•-'-'''  '//   en/nil  n*<  r  is  exactly   analo^oii<  to  a    l.e\'den   jar 

•    numlier  of  sijiiare  inches  of  metal  foil,  and  separated 

:i  iekne>s    of    ;_rla->.       I'ut    a    liat    ula.-.-    plate    considerably 

•  ires  i~  used  in. -tead  of  a  jar,  and  t  lie  di>t  al  surfaces 
-   are  coven-d   by   irlass  plate-  \vliich  extend   beyond  the 

:  are  -o  Me  red  to  i  he  dielect  ric  u'la--  plat  e  by  a  cement 

'}•:<•   -ame  composition   as  the  u'l;'.--.     I  he  condenser 

In  '  '   of  tilass.  containing  in   it-  interior  t  wo  metal 

•  each    other   bv    a    certain    thickness   of   si;la>s.       At 
i  hi    periphe|-y  ni    t  he  i:la--   I  here  are   metallic  n  m- 

iri    .      Tin-  met  hoii  of  const  met  \,  ,n  j  ti'i'\'ent  s 

''.'•.'  e-    place   all    arolilld    t  he   ei  l<jv.-   of   t  lie 

i-li    i-    visible    as  a    violet-colored 

C!      '• .  '.    "'     V  jolel     coli  MVij    -pa  I'k-    at     t  lie    HU  'llielit     (  if 

'  . : '  -     in     I  In      •      iiobt  h     condenser     proem     m  i 
•     .       \-madi    li\    1  !•  iclK-fi  'i1' .   t  hen    a  re  i  ml\"   a 
bet  -A'i  eji    tin     iila-'S    plat  e>   wliei'e   t  he   conl  act 
I  !n  -     1 1       •       ai'i     n    '  la  I   in     '  n  ;--  'j.  ;•   \  acua, 
•     '  '. —  i  if  elect  ricit  v.  and  do  not    tend 

i"  i  I  i  inches 


in  diameter;  while  the  complete  condenser  with  an  ebonite  top  and 
bottom  and  metal  binding-posts  forms  a  disk  about  12  inches  in 
diameter  and  about  1  j  indies  thick.  Two  or  more  of  these  condensers 
can  be  made  into  a  thicker  disk,  and  may  be  connected  in  parallel  or  in 
series  or  in  a  combination  of  the  two  wavs.  This  connection  is  a 
remarkably  simple  matter,  assuming  that  the  condensers  are  all  placed 
one  on  top  of  the  other;  the  binding-posts  of  the  top  armatures  in  the 
various  couples  may  be  turned  toward  one  side  and  those  of  the  lower 
armatures  turned  toward  t  he  oppo.-ite  ,-ide  \  Fig.  17'. I ).  A  .-in  i  pie  metallic 
connection  binds  together  all  the  connections  on  one  side,  ami  forms 
one  pole  of  a  condenser  having  a  capacity  equal  to  the  sum  of  the 
capacities  of  all  the  separate  couples,  while  all  the  lower  plates  are  bound 


Fig.  179. — Rochofort's  monolith  condenser.      Usual   p:ir:illol   cnmicction. 

together  in  the  same  way  to  form  the  opposite  pole.  These  condensers 
can  be  equally  well  connected  up  in  series.  Turn  the  binding-posts  so 
that  in  the  connection  from  the  upper  plate  in  the  first  condenser  shall 
be  toward  the  right,  and  from  its  lower  plate  to  the  left:  and  that  from 
the  upper  plate  of  the  second  condenser  to  the  left,  and  from  it-  lower 
plate  to  the  right.  The  connection  is  made  from  the  lower  plate  of  the 
first  to  the  upper  plate  of  the  .second  couple  at  the  left  of  the  combined 
condenser:  and  from  the  lower  plate  of  the  second  couple  to  the  upper 
plate  of  the  third  couple  (Fig.  ISO). 

Levden  jars  or  Rochofort's  monolith  condensers  are  used  for  the 
extremely  high-tension  charges  of  t  he  st  at  ic  machine  and  high-frequency 
apparatus,  because  glass  forms  a  highly  resisting  dielectric,  and  is  not  so 


VSSS/S,  '- 

•:::::::\Kubb 

1ST  cou/>/e 
Zc/ctwp/e 

ff/ass 

V.  >///.',: 
Jd  coufi/e 

y  —       •  • 

. 

'   1          A/ 

liable  to  puncture  as  paper,  wax.  or  mica,  and  is  treer  trom  imper- 
fections. The  glass  wall  of  a  Levden  jar  or  the  layer  of  glass  between 
the  armatures  in  the  monolith  condense!'  will  resist  the  electric  ten-ion 
required  to  produce  a  (i-inch  .-park  through  the  air.  but  if  a  puncture 
doe-  occur,  the  discharge  melts  a  path  for  itself  through  the  glass,  and 
this  usually  destroys  the  condenser.  (Miter  dielectric-  sometimes 
used  for  high-tension  condensers  are  •  '.  and  coinpressed  air  or 
gases.  There  are  two  chief  requirements  in  she  case  of  a  non-conduct i;  -' 
laver  used  as  the  dielectric  of  a  cimdensi  r  for  high-tension  elect 


-mi  •.••••  tin    [i    up  as  litrhtlv  and  compactly  as  possible.      Kadi  armature 

ni'  t  in -foil  with  a  1 1  it  al  surface  of  about  7-">  square  yards 

I  •  -    s!u  <  !-  nt'  liii-inil  arc  usually  >eparated  from  each 

ni  in'T  i  in  I  paper  or  by  sheets  of  mica.     There  is  not  the 

as  in  the  case  of  hijjh-t ension  currents.      The 

•  ire>    ainl   dielectric   are  consolidated    under   heat    and 

!•:••--•.:•.  -ii  a-  to  form  a  -"lid  Muck  which  may  lie  concealed  in  the  base 

>•    -.  parate  i  rom   n.     Such  a  condenser  usually   has 

:   in  surface  or  parallel,  so  ihal    1  he  fir-t   and  the 

•  :'i!t,   •  •<•..   metal  -heei>  project    at   one  end.   and  are  all 

ith  one  electrode,  and  really  form  a  single  armature 

•     •  "U-l'     lar^e  surface.      'I  he  older  set  of  metal  sheds,  the 

•  c..  project  hey ond  t  he  ot  her  edge  of  t  he  paraffin 

-.  ami    ;  i  l>y  a   single  electrode    to    form    another   single 

'  UP    •  '!  very  la ri_re  surface. 

i  IT.  1 M  .  A,  -hov-  in  a  diagram  mat  ic  way  the  const  rue  lion  of  such  a 

-er.   \v!t!i  the  two  opposite  sets  of  metal  sheets   interlacing  and 

:  prevent  in  <r  contact  between  any  metal  sheet  with  any  of 

-''.      In    actual   construction   the   metal   sheets   are   much 

"  tiiir'-thi  r;  there  i<  no  air-spac( — only  the  thickness  of  the  paper 

•••     them.      The  external  extremities  of  each  set   of  metal  sheets 


4- 


'•'  a  en  iss  n  >•!.  as  in  i  he  diagram,  but  are  pinched  together 
!>•      I  .'.'  re  are  many  more  of  the  different  layers  than 

•  vised   by   the  author  as  a  convenient    dia- 

ilion    Ml     a    conden.-er.      (  Mie    set     of    metal    sheets 

i'^  e  p-i|e  o|  t  he  elect  ric  general  or  interlace  with 

;•  po-ii  i\'e  pole.     The  dielectric  separating  the 

^   represented   by  the  space  between  them  in 

'  '      •    '    •    •    •      'I  he    familiar    process    of 

'.   1  s-'.    where  i  me  elect  n  >de    (from 

-    tolleiied    to    I  l,e    positive    pole 

iher  eleet  fode  M'fom  t  he  external  armature 

1  •   '    '  i\  ••  pole  of  the  static 

b.    Mil    ei  mi  lit  ii  iii    -In  iwn    in  l  he  diagram 

'"•''  ;  '      .  and  it-  outer 

.    iv. 

"I    I  he    many-leaver]    condenser 

I  s->.        \  lieel  ion  i    \]'-1  -  bet  ween 

1     :    '  Hie    i  li  c1  fode    of    i  he    con- 

'  'i     neural  i'.'e    elect  ficit  y. 

.'  tl     po-it  ive    ,   left  ficit  V     b\' 


DYNAMIC    KLKCTKHITY 


241 


direct  connection  with  the  positive  pole  of  the  battery.  Xo  current 
can  flow  under  the  conditions  sho\vn  in  this  diagram,  since  the  two 
armatures  are  separated  by  a  non-conducting  dielectric  and  the  circuit, 
is  not  completed  in  any  other  way.  If  the  buttery  should  suddenly 
give  out,  the  condenser  would  discharge  itself  through  the  conducting 
wires  and  through  the  electrodes,  and  the  liquid  electrolyte  of  the 
battery.  The  direction  of  the  current,  from  the  condenser  would  be 


Fiji.  1S2. — Charging  a  Leyden  jar  from  a 
static  machine. 


Fin. 


{.  —  Charging    a    rondcn.-or    from   a 
voltaic  battorv. 


from  its  positive  electrode  through  the  conductor,  through  the  batten', 
and  through  the  other  conducting  cord  to  the  negative  electrode  of  the 
condenser.  The  path  thus  described  corresponds  exactly  with  the 
discharging  rod  by  which  a  J.eyden  jar  may  be  discharged.  Fig.  1S4 
shows  how  such  a  metal  rod,  held  by  an  insulated  handle,  may  be  applied 
to  the  two  electrodes  of  a  Leyden  jar,  and  allow  the  current  to  ilow 
between  the  two  until  the  positive  and  negative  charges  are  neutralized. 
Here  as  well  as  elsewhere  the  direction  taken  by  the  positive  charge 
is  called  the  direction  of  the  current. 

"V  " 


Fiff.  1S4.— -Disehartnn"  a   I.cydcn 


liattcr\     cm-nit     and    liccnmiim    charged    when 


jar  !>y  means  of  a  discharging  rod 


an  insulated  nan 


Figure  IS")  shows  a  similar  case  to  thai  in  Fig.  IS.",,  except  that  there 
is  an  interrupter  at  I,  which  is  open  in  this  diagram,  but  which,  when 
closed,  forms  a  complete  circuit  for  the  battery.  The  interrupter  beint: 
open,  there  is  no  current  flowing,  but  I  he  positive  and  negative  plates 
of  the  condenser  are  charged  with  electricity. 

('losinii'  the  interrupter  as  in  Fiu.  1st'..  ;)  double  effect  is  produced. 
First,  the  condenser  become-  discharged  by  the  pa->auv  of  a  current 
from  its  positive  armature  through  a  -hurt  conducting  cord  to  the 
it; 


MKI>h  AI.     Kl.Ki  TKIc   II  V    AND    KoNTt.KN     HAYS 


hack  through  tlir  other  slmrt  conducting  conl 

;,,    •;..  ulc    Hi"    the  condenser.       Second,    a  current    flows   iTOlll 

•   •;.,•  voltaic  battery  through  tin-  cunductiiig  cord  to 

ii  nee  through  the  other  conducting  cord  to  the 

pule  (.f  the  liattery,  and  through  the  liijiiid  electrolyte  to  the 

1,-.     As  1  •  terrupter  is  dosed  the  battery  current 

[he  i-i  uidetiser  remain.-  uncharged. 


:_'.   1S7.     -Condenser  in  shunt  to  the  pri- 


mary   wire   (if   an    induction    coil.      (  'oinpleti 


t     and    di-charui'    of    condenser. 


iw.   the  interrupter  opens  as  in   Fig.    IS."),   the  battery  current 

-  fur  a  -hurt   time,  not   making  a  complete  circuit,  but  flowing 

condenser   until   it    is  fully   charged.      Then   things   remain  as 

1  in  the  fir-i  reference  to  Fig.  is."),  until  the  interrupter  is  again 

closed. 

Tin  /•,'//'*('/  of  a  Condenser  I  /><>//  the 
I'rin/ii/i/  Current  of  <ni  Induction  Coil. — 
The  diagram-  in  the  preceding  paragraphs 
have  been  devi-ed  by  the  author  as  a  pre- 
liminary to  those  illustrating  conditions  in 
ad  ual  pract  ice. 

Figure  1ST  -hows  the  condition  when 
the  interrupter  is  closed.  The  condenser  is 
not  charged.  A  current  flows  from  the 
positive  electrode  of  the  battery  through 
the  conducting  cord,  through  the  primary 
coil  and  interrupter  and  conducting  cord 
to  the  neuative  electrode  of  the  battery, 
and  through  the  liquid  electrolyte  to  the 
po-itivc  electrode.  At  the  beginning  this 
cnlary  current  in  the  opposite  direction  in  the 


•  M  opened  a-  in   Flu.   iss.  and  this  is  automatic 

'•a-c-   :.-.    the  rnairnetic  attraction  of  the  soft- 

i  he  hammer  <  if  t  he  interrupter. 

•  '     '  •''•   ''iine'il    i  liKiuuh   the   primar\-   coil   to 

. 

•    '  n!  in  it  -  ( iwn  direct  i<  in  in  1  he 

1     of  the   hat tery   current    in    the 

'>''  -d  i  >r  '  \t  ra  current .  pr<  iduced  in  the 


DYNAMIC     KLKCTKHITY  243 

primary  coil  by  self-induction.  This  extra  current  has  two  deleterious 
effects.  First,  it  is  of  high  tension,  and  sparks  to  a  disagreeable  and 
injurious  effect  across  the  open  interrupter;  and,  second,  it  forms  a  sort 
of  continuation  of  the  primary  current,  which  should  cease  quite 
promptly  in  order  to  induce,  at  its  break,  the  best  possible  current  in 
the  secondary  coil. 

The  beneficial  action  of  the  condenser  is  in  the  correction  of  the.-e 
two  deleterious  effects  of  the  extra  cm-rent  in  the  primarv  coil.  This 
extra  current  rushes  first  into  the  condenser  and  charges  its  manv- 
leaved  armatures,  one  with  positive  and  the  other  with  negative 
electricity,  and  the  capacity  of  the  condenser  is  calculated  to  be 
sufficient  to  receive  all  the  current  which  would  otherwise  form  a  spark 
across  the  open  interrupter.  l>y  the  time  the  condenser  is  fully  charged 
with  this  high-tension  electricity  the  high  electromotive  force  of  the 
extra  current  in  the  primary  coil  has  disappeared.  The  condenser  is 
now  fully  charged  at  a  higher  tension  than  the  electromotive  force  of 
the  battery,  and  it  at  once  becomes  discharged.  It  sends  a  current  from 
its  positive  electrode  through  the  conducting  cord,  the  battery,  and  1 1n- 
other  conducting  cord  to  the  negative  electrode  of  the  condenser.  Tin; 
interrupter  is  open  during  this  time,  which  is  very  short.  The  discharge 
from  the  condenser  also  surges  into  the  primary  wire  when  it  is  in  the  op- 
posite direction  to  the  battery  current,  and  its  effect  on  the  current  in  the 
primary  coil  is  not  only  to  bring  the  primary  current  to  a  stop  almost  as 
soon  as  the  interrupter  has  opened,  but.  in  addition,  to  produce  a 
countercurrcnt  in  the  primary  coil.  The  latter  has  an  inductive  effect 
on  the  secondary  coil,  augmenting  the  effect  of  the  cessation  of  the 
primary  current.  The  break  current  or  the  secondary  current  induced 
by  the  cessation  of  the  primary  current  and  flowing  in  the  same  direction 
as  the  primary  current  is  of  greater  strength,  and  has  more  important 
uses  than  the  make  current.  The  condenser,  therefore,  has  great  value 
in  every  case  in  which  the  extra  current  is  a  disturbing  factor  in  depriving 
the  coil  of  the  effect  of  a  prompt,  and  complete  cessation  of  the  primary 
current  at  the  time  that  the  interrupter  is  opened. 

Cases  in  which  an  Induction  Coil  AYr/////T.s'  a  Condenser. — Coils  usinira 
heavy  primary  current,  6  or  more  amperes,  and  a  mechanic  interrupter, 
always  require  a  condenser.  .r-Ray  coils,  therefore,  except  those  with 
a  liquid  interrupter,  require  a  condenser.  (vSee  page  14S.) 

Cases  in  which  an  Induction  Coil  l)<»  x  \  <>f  Required  Condrtifn  r. — Coils 
which  are  intended  to  cany  only  a  small  primary  current  do  not  usually 
need  a  condenser,  although  they  are  usually  made  with  mechanic 
interrupters.  Faradic  coils  are  in  this  class.  The  Y\  ehnelt  and 
Caldwell-Simon  interrupters  produce  a  quality  of  break  in  the  primary 
current  which  yields  an  excellent  inductive  effect  without  a  condenser. 

The  familiar  experiment  of  interrupting  the  flow  of  the  primary 
current  by  cutting  the  wire  with  a  bullet  from  a  rifle  produces  so  rapid 
and  complete  a  break  of  the  primary  current  that  the  condenser  proves 
to  be  unnecessary. 

The  Potential  and  Capacity  of  a  /.<  <'/<>/  Jar.— An  insulated  metal 
ball  (Fig.  LS9,  A"),  connected  with  the  positive  pole  of  a  static  machine, 
will  be  charged  to  the  same  potential  or  the  same  number  of  vit- 
as that  pole  of  the  machine,  and  it  has  been  established  by  experiment 
that  the  quantity  of  electricity  which  i'  \vill  receive  or  its  capacity  at 
that  potential  is  q=-VR,  \l  being  the  i  is  of  the  sphere  A. 


i:i.i:eTRierry  AND  RONTCEN  HAYS 


h"  thi-  -phere  he  surrounded  1  .y  ;in  (Eternal  conducting  shell,  B, 
ted  from  the  -phere  A  by  a  layer  of  air  or  other  dielectric  sub- 
:  connected  with  the  earth,  the  static  machine  still  continuing 
to  maintain  a  potential  of  V.  the  inner  positive 
sphere  will  at  first  induce4  a  charge  in  the  outer 
shell  which  will  attract  negative  electricity 
into  the  shell  from  the  earth,  and  repel  posi- 
tive electricrv  from  it  into  the  earth.  The 
negative  charge  upon  the  shell  will  in  turn 
act  upon  the  inner  sphere  A.  and  attract  into 
it  a  larger  positive  charge  than  it  could  have 
received  without  this  influence.  This  is  the 
well-known  principle  of  the  condenser.  Two 
conductors  separated  by  a  non-conducting 
di'-lectric  have  an  increased  capacity  for  elec- 
tricity, and  if  charged  to  the  original  potential 
V.  each  will  contain  a  quantity  of  electricity 

<  ^   and       t{.  which  is  greater  than  cither  could   have  been   made  to 
receive  I'roin  the  same  source  of  potential  when  by  itself. 

The  potential  y  of  the  inner  -phere  is  equal  to       _,    .  and  that  of  the 

J  L 


H     •   ;i  lesser  potential,  the  latter  var\'ing  as  the  quantity  divided  bv 
adius. 
:     •     :     lential,    \",   of  the   whole  jar   is    made   up   of   two    parts,    the 

•-;•  ive    poti  nt  i;d  of  the  inner  sphere.   \"  : 

J  i 


and  the  negative 


.    \'1   •  .       The   combined   ]>otential 

<  >  QfR1  -  Hi  \'  R  P1 

R>'N  RR>        •"r(^U'-R; 

ve  found  an  e\]>ression  for  the  difference  in  potential 

."•  :   and  inner  coat.-  of  a  Leyden  jar  of  complete  spheric 

•s  of  whose  dielectric  is  R1— H.      J!1  is  the  radius  of 

ire.   ,  :    ;    I!    the   radius  of  the  inner  sphere,  and  (,).  the 

;i    i-   found   as   a  positive  charge  upon   the 

-    a    negative    charge   upon    the   outer   armature. 

'      :  .    to  consist   of  i\vo  ci,mplete  concentric  spheres. 

y  R  R! 

I    /.  1  ss  .  lie  charge  is  O  ,      and  if  li 


.  t   being  the 


'1  III    1'nli  nt  nil  nj  n   ('nini<ii*ir 

Q  x  4  /  :;.]  i  K;  •  t 

s 

The  Capncitif  <>j  d  (  '<>n<l<nx<r 

This  is  the  quantity  of  elect  ric  it  \'  required  to  charge  il  to  a  potent  ial 
of    one    volt.      Calling   ('    the   capacity, 

S 


ii(i  x  t 

If  a  number,  n,  of  condensers  of  the  same  si/,e  are  joined  in  surface. 
the  combined  capacity  is  the  number  •//  times  that  of  a  single  couple. 
They  correspond  to  one  large  condense]-  with  //  times  the  surface,  but 
with  the'  same  thickness  of  dielectric. 

If  n  condensers  of  the  same  size  are  connected  in  series,  they  corres- 
pond to  a  single  couple  with  the  original  surface  of  one  condenser,  but 
with  a  dielectric  n  times  as  thick.  Their  combined  capacity  is,  there- 
fore, n  times  as  small  as  that  of  one  condenser. 

The  capacity  of  a  condenser  of  glass  1  millimeter  thick  and  with  a 
total  coated  surface  of  1  square  meter  is  J-  microfarad.  The  capacity  of 
other  condensers  of  different  surface  or  different  t  hick  ness  of  dielect  ric.  or 
with  a  different  dielectric,  can  readily  be  calculated.  The  capacity 
varies  directly  as  the  surface  and  the  inductive  capacity,  and  inversely 
as  the  thickness  of  the  dielectric. 

si'innc  ixnrrnvF,  CAPACITIES.     Gordnmmd  snow.) 

Air,  1  .0  Tin-pent  inc.  '_'.  l(i 

(;ias>.  :;.0i:5  to  '.).2.'^  Petroleum.  2.(Ki  to  12.07 

Kbonitc.  2.284  Hisnlphid  of  carbon.  LSI 

Gutta-percha,  2.402  Vacuum,  o.'.i'.i'.it    Uoltzmunn) 

India-rubber,  2.220  to  2.497  Hydro-mi.  O.'.i'.i'.iT    Boltxmaim  - 

Paraffin  (solid),  1  1HK50  Carbonic-arid  gas,  l.non:!    Uolt/munn 

Shellac,  2.74  Carbonic-acid    <:a>.     l.ooos      .  \yrton    and 

1'crry  i 

Sulphur,  2.58  Sulphur  dioxid.  1.00.'>7 

The  experiment  of  the  dissected  Leyden  jai%  shows  that  the  two 
opposite  charges  are  held  upon  the  surface  of  the  glass,  even  if  the  outer 
metal  coat  or  armature  is  removed  and  freely  handled,  and  the  same 
thing  is  subsequently  done  with  the  inner  armature.  Certainly  no  charge 
remains  on  the  metal,  but  the  moment  the  metal  coals  are  replaced,  the 
Leyden  jar  may  he  discharged  bv  touching  both  armatures  at  the  same 
time.  4'  he  armatures  and  thedischarging  md  form  a  met  al  conductor  from 
the  charge  upon  one  surface  of  the  glass  to  that  upon  the  other  surface. 

Air  forms  an  excellent  dielect  ric  for  a  condenser,  and  is  used  for  that 
purpose  in  some  types  of  high-frequency  apparatus.  Its  ntilitv  i< 
greatlv  increased  when  under  pressure,  since  air  then  becomes  a  better 
insulator,  and  disruptive  discharges  and  efHuvia  are  prevented. 

I'l'dcficd  I'lilii'/  />t  '  Cotnli  />.->  :•.-•.  I'  \  •  -  Idom  that  any  practical  use 
is  made  of  the  experiment  in  which  ;i  i.eydeli  jar  may  receive  a  chariie 
and  then  be  disconnected  from  the  tTenerator  and  retain  it.-  charge  until 
a  conducting  path  is  brought  near  '  '  to  both  armatures  to  permit 

i  it  a  disrupt  ive  disdia  rge. 

When  this  disrupt  ive  discharge  tal  e-  place  over  the  sreatest  stri 
distance,    t  h(>   condense]1   lose-    all    bin          of  its    charire.       !!..•    :v- 
charge  mav  be  discharged  in  the  sami      -av  1>\    bringing  iln    discharging 


•Jit. 

j-,,,1    nearer   t«i   the   two   armatures.      And   aiiain   there   remains  a  small 
|llt..        \  ><-rie>  ni'  sparks  may.  t  herei'ure.  be  obtained  until    finally 

•  ;  :  ni.-l    be   placed  in  actual  contact  with  both  arnia- 

.;e  ;  he  ci  mdenser. 

>  /•;/,  >,  //  »,.  and  <><>t  "j  a  (.'nndrnser. — The  function  of 

;;  ,.,,n  ;      --  •    L-    ,-  .   ll\    to  act    as  a   reservoir  into  which  electricity   is 

•   pi  ci  1,1-  .  •   '-.: •:•  a.-ed  pressure  in  a  circuit,  and  from  whicli  it 

iii  again  at  periods  of  low  pressure.     The  double  bulb 

nl  a  •  i.-  •••.:••  in  -'.  rin lie  or  atomi/er  furnishes  a  partial  analogy. 

1-.  •':...-  ,    -    •  — :nv  oi  tiie  hand  exerted  in  squeezing  the  first  bulb 

-   •;  ,    -,  , •    •    .   '••  illi  to  expand  and  receive  a  portion  of  the  air  or 

,-ise  be  forced  through  the  tube.      When  the 

.-;;;      >    relaxed,    the    pressure    thus   produced    in    the   second   bulb 
;•  -   iir  or  liquid  into  t  he  tube  again,  and  there  are  generally  valves 

•  it   in  •':..    direction  of  the  current  flow.     The  object  in  the  case 
•  •       -vrii.iii    i-  to  secure  a  uniform  instead  <>f  a  pulsatile  flow,  and  this 

i-iii-i]  by  suital)le  regulation  of  the  size  and  elasticity  of  the 
lib.      I:    must    not    completely   empty   itself  before   the   next 

:    t  he   tii'.-t    bulb. 

Tin  n-er   in    an   electric   apparatus   receives   its   charge   under 

-MIIV  ju.-l  like  the  second  bulb  of  a  syringe,  but  it  gives  up  the 

mre  promptly    -in  fact,  almost   instantaneously— 

•  •;.«•!-:.    in   tension   in   the  circuit.      The  condense!1  becomes 

fore  the  period  nf  lo\v  pressure  is  finished,  and  the  tension 

;    :    .    i;oi    rendered    uniform.     Another   difference    is   that    the 

•.   o]    the  interrupter    stops    the    current   in  the  original 

,       •       irrent  due  to  the  high  pressure  in  the  condenser  and 

:•     --  ire   ii     the  circuit    is  compelled   to  follow   a  direction   the 

••      •     M!H   original  current .     Thus  the  charge  during  a  period 

:•••'•     I  i  i-hes  into  the  lariie  capacity  and  insignificant  resist- 

:    user  only  to  surge  out    again  during  a  period  of  low 

'         '    '  •  •     'ij'cu it 

'.:.'•••'  '''  -  n|  'In-  condenser  with  the  circuit   are  not  made  and 

-  operation.       ]  lie  condenser  terminals  may  even   be 

'   tin1  battery  circuit.      The  making  and  breaking  ol 

•  in 'i  rruptef  do  not  occur  on  any  line  leading  to  or  from 

'•  rnipter  and   the  condenser  are   in   shunt    to 

i'v     pa->es    throiiirli     the    primary     coil     and   the 

'''  '    i.-   closed,    but    has   to  take  the  other  path 

-er  -shell   the  interni])ter  is  opened  and  the 

;  iced   in   t  he  primary  coil. 

The    Capacity    of     Circuits,      \\liile    condensers    have    very    great 

•  '  -  I'V   cond  (c|  iir  i  it    i  •led  rn'it  y   has  a   cert  am 

-  a   prepa  rat  i<  >n   fi  >r  t  he  t  ransmission  of 

tension  current  -  in  t  he  case 

.  where  an   impulse  requires  an 

t  he   wire.      Tlii-   limits   t  he 

They  are  m  >i  in.-t  ant  anei  .us. 

'  lie  kcv  and  thus  n  umect  ing 

:    ".    uniformly   as   long  as 

wire  assumes  t  he  con- 

p"t  i  n  t  ial.  and  has  a   1  emlencv 

'  h  '  ifdinarilv  a \-ailable 


DYNAMIC     KLK<  TKIdTY 


is  at  a  distal  point,  and  so  all  the  current  commonly  (lows  in  that  direc- 
tion, but  there  is  the  same  pressure  in  all  directions.  There  does  not 
appear  to  bo  anything  which  could  be  called  electric  momentum.  It'  a 
current  continues  to  flow  in  a  given  direction,  it  is  because  of  a  continued 
pressure  or  difference  in  potential,  and  the  current  will  not  continue  to 
flow  for  an  instant  at  any  point  in  a  direction  contrarv  to  the  pressure 
at  that  point.  Take  a  long  wire  (Fig.  100)  starting  from  the  positive 
pole  of  a  battery  whose  negative  pole  is  grounded,  let  this  wire  have  a 
key  for  turning  the  current  on  and  off  near  the  battery,  and  let  it  run 
to  a  telegraph  receiver  near  the  other  end  of  the  line  and  beyond  that 
be  grounded.  When  the  key  is  tinned,  a  current  passes  through  the. 


I'ijz.  100. —  Battery  and  telegraph  wire  illu-tratiuc;  capacity  of  the  latter. 

wire  and  telegraph  instrument  to  the  ground,  and,  of  course,  re 
through  the  ground  to  the  negative  polo  of  the-  battery.  If  the  key  is 
lifted  and  the  electromotive  force  of  the  battery  is  cut  off  from  the  wire, 
there  is  no  piling  up  of  electricity  in  the  distal  part  of  the  wire,  leaving 
no  charge  in  the  proximal  part,  as  would  tend  to  be  the  case  if  water 
were  Mowing  rapidly  through  an  inclined  tube  and  a  stop-cock  were 
turned  at  the  top  (K'1,  Fig.  101).  In  the  latter  case  the  inertia  of  the 
water  would  create  a  minus  pressure  near  the  stop-cock  K1.  Nothing 
analogous  occurs  in  the  case  of  electricity.  Looking  at  the  other  end  of 
the  wire,  suppose  the  key  near  the  battery  is  kept  turned  on  all  the 
time,  but  there  is  a  key  near  the  telegraph  receiver.  If  this  key  is 


Fi«.  191.  —  Inertia  of  water  flowing  t  lii-onirh  an  iiteline'1  tut 

turned  off,  there  is  ordinarily  m>  continued  onward  pressure  of  elec- 
tricity, as  there  would  be  of  water  in  Fiir.  101  if  the  stop-cock  1\-  at  the 
lower  end  of  the  inclined  tube  were  turned  off.  In  the  case  of  water, 
the  motion  into  the  lowest  part  of  the  tube  would  continue  in  spite  of  a 
developing  adverse  pressure.  This  pressure  is  mvat  enough  sometimes 
momentarily  to  carry  the  water  in  the  stand-pipe.  P.  to  a  higher  level 
than  that  of  the  original  reservoir.  In  the  hydraulic  ram  the  inertia 
of  a  body  of  water  falling  through  a  \ertical  pipe,  and  arrested  at  tiie 
bottom  at  intervals,  is  used  automatically  to  compress  air  and  force 
water  to  :l  much  higher  level  than  that  of  the  water  in  the  reservoir. 
A  liquid  or  anv  solid  body  in  motion  acquires  a  momentum  which  will 
produce  a  certain  pressure  at  the  point  of  impact  if  it  be  suddenly 


•Jl^  Mi.mt  AI.   1.1.1:1  nucri  v   AND   KONTCKN   HAYS 

arrested   by   some  nh-t  acle.      The  pre»ure   is  momentary,  and   is  very 

•   i!ir  \\.  mill  ni'  tin-  moving  body  and  ils  velocity  are  both  great. 

>n  ;;j  'plied  as  to  impart  t  lie  saint-  velocity  to  an  equal  mass  or 

to  impart   a  greater  velocity  to  a  smaller  mass  or  a  less  velocity  to  a 

greater  mass  of  mat  ter. 

AM  eleci  ric  current  tlowini:  through  a  short  straight  wire  and  suddenly 

arrested  produces  no  such  etTect.  n«r  should  we  expect  it  to  when  we 

inderahle  nature  and  the  double  directional  character 

uiges  in  a  material  path  which  constitute  a  so-called  electric 

•  ' . 

The  <  \ i  ra  current  with  its  spark  at  the  interrupter,  when  the  primary 
<•'      .'•      :  coil  is  broken,  does  not   indicate  the  existence  of 

c!   .  t  ric  n  on  i  ntum.  1  'Hi  i>  produced  hy  indue  I  ion. 

1  :  ,  ction  iii  the  case  of  the  Atlantic  cable  results  in  its 

••  nth  second  before  i  he  first   trace  of  a  signal  is  received  at 

•  nd.  and  the  full  suvngth  of  the  current  not  being  registered 
live  >eciiiids  later.      An  expert  operator  can  .send  about  twenty 
a   •    iuute.      There  are  some  most    wonderful  facts  in   regard   to 

trie  transmission,  one  being  that  a  voltaic  cell  consisting  of  a  per- 
c  i--!  i-d  with  dilute  acid  into  which  a  zinc  rod  is  dipped  can 

irnal  across  the  Atlantic.     Much  stronger  currents,  of  course. 
an      l-Ualh    empli  i\"ed. 

ELECTROLYSIS 

1  his   i-  a  rhemic  change  of  decomposition  which  often  takes  place 
i'      '  which  a  current  of  electricity  passes. 

The  products  of  electric  decomposition  are  called  ion*.     Cations 

•  or  :>penr  at   the  negative  electrode  or  cdtJioth  .  and 

>-itive  electrode  or  (n/ixlr.      Fig.  192  shows  the  classic 
experiment    of    passing    a    current    of    electricity 
Hirough  water,  slightly    acidulated    to    render    it 
a    Lr<»Hl    conductor,  between    ))latinum  electrodes. 
The     two     inverted     glass     tubes    over    the     elec- 
trodes  are  coni])lelely  filled  with  water  and  open 
lively   mid  the   ciimmon   trough  of   water    below. 
\\hen    the   current    from  a    battery  or  other  gen- 
crator    yields     a     potential    of     1  .1     volts   or    over. 
-    'he  electric   current    flows  through   the  liquid. 
bubbles    of   hydrogen    gas    form    at    the    negative 
electrode,  and   rise  (o  the  top  of  the  tube,   where 
thr-v    -non    torm    an    appreciable  volume    of    o-^p. 
!'"'  same  way,  and   (ills  the  top  of  the  tube 
1    ('lfci  rode.       \  certain  p,,n  i«,n  of  the  water  has 
~  con.-t  it  uent    element-,   and    it    contains  twice 
'•''     '•  "lun  '••      \\  «•   find    an    indication   of 
•    lai  Lri '   a    vi  iluine   of   h\-dron-en    jr;is 
'1    "N}  '-''  M    Lra-    iiver  t  lie   posit  ive  elect  rode, 
uo  1,.  .in..,   because   !,;,  drogc-n    j<   more 
ice  o]  the  elect  n  \<\c  ami  also  |>v  t  he 


241) 

electricity  which  flows  through  an  apparatus  by  not  ing  the  amount  of 
chemic  decomposition  produced.  The  simple  product  which  is  measured 
may  be  a  gas,  as  in  the  case  of  the  water  voltameter,  or  it  mav  be  a 
metallic  element,  as  in  the  case  of  the  silver  voltameter.  In  this 
instrument  the  positive  electrode  is  of  silver,  the  electrolyte  a  solution 
of  silver  nitrate  of  a  standard  strength,  and  the  negative  electrode  a 
sheet  of  platinum.  During  the  passage  of  the  current  metallic  silver 
is  deposited  as  a  silver-plating  upon  the  negative  platinum  electrode, 
and  dissolved  away  from  the  positive  silver  electrode.  The  platinum 
having  been  accurately  weighed  before  and  after  use,  its  increase  in 
weight  shows  the  amount  of  silver  which  has  been  deposited  or  separated 
from  its  combination  with  nitric  acid.  Within  reasonable  limits  the 
amount  of  silver  so  deposited  indicates  t  he  quant  it  v  of  elect  ricit  v  which 
has  flowed  through  the  meter,  /.  r..  the  number  of  coulombs  irrespect  ive 
of  the  rate  of  flow.  One  coulomb  of  elect  ricit  v  will  deposit  0.001  Ms 
gram  of  silver.  A  current  of  1  ampere  is  a  current  flowing  at  the  rate 
of  1  coulomb  per  second,  and  will  deposit  0.001  MS  gram  of  silver  per 
second.  This  is  at  the  rale  of  about  1  grain  a  minute  (English  weight ). 
A  current  of  1  milliampere  would  require  a  thousand  seconds  to  deposit 
the  same  0.001MS  gram  of  silver. 

The  copper  voltameter  has  two  copper  electrodes  and  a  10  per  cent, 
cupric  sulphate  solution  as  an  electrolyte.  It  is  accurate  to  within  a 
fraction  of  1  per  cent.,  and  was  formerly  extensively  used  in  measuring 
the  electric-light  current  and  determining  the  amount  to  be  charged  by 
the  com  pan}7  for  the  use  of  the  current. 

A  voltameter  gives  correct  readings  only  with  a  direct  current  and 
with  a  certain  strength  of  current .  In  the  case  of  the  copper  volt  a  meter, 
this  corresponds  to  a  current  density  of  about  0.01  ampere  per  square 
centimeter  of  cathode.  The  voltameter  is,  for  economy  of  power, 
placed  in  shunt,  so  that  only  a  definite  fraction  of  the  current  passes 
through  it.  The  size  of  the  cell  and  its  electrodes  varies  somewhat 
with  the  strength  of  the  current  which  is  to  be  used,  although  a  wide 
range  may  be  obtained  from  a  single  voltameter  by  varying  t  he  multiply- 
ing power  of  the  shunt .  In  this  way  the  same  weight  of  copper  deposited 
and,  of  course,  the  same  quantity  of  electricity  passed  through  the 
voltameter  indicate  the  consumption  of  a  large  or  a  small  amount  of 
."urrent,  depending  upon  the  shunt.  The  multiplying  power  of  the 
latter  must  be  known  to  make  the  voltameter  ot  any  value  at  all. 

The  voltameter  finds  its  chief  utility  in  the  case  of  a  direct  current 
having  always  approximately  the  same  strength  or  amperage  and 
the  same  potential  or  voltage  when  it  is  being  used  at  all.  I  he  volta- 
meter gives  the  total  quantity  of  elect  ricit  v  which  has  flowed  since  the 
last  reading  was  made,  and  gives  a  total  of  all  the  short  or  long  periods 
that  a  stronger  or  a  weaker  current  has  beer,  turned  on. 

An  amperemeter  would  not  give  thn  inlonnation  unles-  there  were 
some  one  t  here  to  note  the  strengt  h  of  I  he  current,  and  how  long  it  was 

1 1  e  the  average  st  t'engt  h  of  the 
>i    had   flowed. 

The  meters  in  commercial  use  at  the  present  time  are  mostly  based 
upon  the  magnetic  effect  ofthecun  ;  are  of  the  nature  of  duck 

w<  >rk  run  bv  an  elect  ric  motor.      'I  his  has  t  lie  advantage  that  it  may  be 
constructed  to   measure  either  alternai  i  -    01    direct   currents,  and 
's  readings  are  directlv  visible  upon  a  dial  on  the  outside  ol  the  meter. 


'2"i(l  MKDIi'Al.    KI.F.t   1  1U(  ITY    AND    RONTGEN    KAYS 

Reversible  Electrolytic  Cells.      In  practically  every  case  when  a 

lit       :    electricity    ha>    been    passed    throuiih    an    electrolyte,    if   the 

electrodes    are   disconnected    from    the    battery    and    connected   with  a 

galvanometer,   this  instrument   will   be  deflected.      It   will   indicate  the 

presence  -.MI    in  the  opposite  direction  to  the  battery  current 

usly    been    flowing.      This   current    is   due    to    chemic 

L:  place  at  the  surface  of  the  electrodes  and  in  the  electrolyte 

reverse   of   those    previously    produced    by    the   battery 

tit.      A    Morale-cell    or   accumulator   affords    the    best    example   of 

reversed  <i'  < •'!'":: ,ot  i \-i •  force  in  an  elect rolyt  ic  cell.    The  most  sensitive 

v  be  applied  to  a  substance  with  a  view  to  determining 

•..  hi  •  in  :  it  i-  an  elect  rolyt  e  or  not  is  first  to  run  a  battery  current  through 

til  urn  electrodes,  and  then  see  whether  it  shows  reversed 

I'a.-.-inn  an  electric  current  through  an  electrolyte  between  electrodes 

•  •   ai        -  •    ,  produces  substances  at  the  two  electrodes  which  form  the 

•  ,:  voltaic  battery,  and  are  ready  to  generate  a  reverse  current 

••  the  excit  ing  electromotive  force  is  removed.     The  products 

trie  ill-composition   are  often  one  or  both  of  them  gaseous. 


-  lasts  only   a  .-hurt    time.     The  storage-battery,   on   the 

: ;.  .  produces  >"l'd  compound:-  at  the  elect  rodes  during  the  passage 

LMMIZ  i'urn  1,1  and  the  cell,  after  disconnection  from  the  charg- 

'.'-.  acts  in  every  respect  like  a  most  efficient  voltaic  cell. 

i    •     cotinieri-li-ct roinot ive    f,,rce   of   an    electrolytic    cell    is   present 

'.,  the  pa— a<_ri'  of  the  primary  current  through  it.     Two  observa- 

-    fact.      A    portable   ./--ray   outfit    may   be   run    by  a 

ha  rued    from    a    dynamo   operated   by    a   belt    from    a 

-•'•tied   upon    a   suitable  support.      A   man   has   to  work   very 

'•'•p  tin    hicycle  pedal-  going   and  the   dynamo  revolving,  and 

-'.'.-    current     flowing    through    the    storage-cells    against    the 

ive  force  developed  in  t  he  hit  ter.      The  power  required 

-  nl   the  bicycle  while  charging  six  cells  at   once  is  so 

•  '    •  '    can  hardly  keep  at  work  more  than  fifteen  minutes 

i  hi  ':  be  relieved  by  another  man.      Thus  the  work 
!"!'    ten    or    twelve    hours.      Where    the    electric-light 
'    •    -ame  amount  of  power  is  consumed. 

the  coiintt-relect  romot  ive  force  present  dur- 

'  •  '       :  ni  percept  ibly  decomposed  into  hydrogen 

ion    of    11    or  '_'   volts   is   applied.      A   smaller 

en!    to    pass    through    an    electrolyte,    such    as 

'•  :   acts  as  an  ordinary  conductor,  and  not 

plied  elect  romot  ive  force  is  greater  than 

'•     loi'ci.    in-derated    by    the    products   formed  at 

•    it ,       I'hi'    p'  iwer    required    t  o    send    a    weak 

••  ci  induct  i  »r  i-  ii'  >t   -uflicii'iit   al.-i »  to  gen- 

1     'I        mill    I  '.  Volt  s  elect  r>  iinot  ive  f<  irce. 

'  l\'e     1'  irce    i  if    an     elect  r<  ilvt  ic 

',\'<'  shall  not  only  have  a  current 

'  m  ic   c  ha  1 1  ijes    apparent    at 

-!!'•   to   those   which    tend 

;:    will    be    produced    there 

•  •  •  iiinect  e<l    from    t  he    excit  inn 


DYNAMIC     KLKCTKICITY 

electromotive   force.     The   vol 
acidulated  water  varies  from  1. 
trodes,  to  an  extreme  of  'J. -Is  vo 
a  mercury  cathode. 

An  electrolyte  is  a  substance  which  undergoes  decomposition  when 
an  electric  current  is  passe*  I  through  it .  The  decom  posit  ion  may  consist 
in  a  separation  of  the  substance  into  its  elements,  as  in  the  case  of 
water,  which  is  separated  into  hydrogen  and  oxygen ;  or  in  t  he  separat  ion 
of  a  highly  complex  body  into  simpler  compounds.  The  electrolytes 
commonly  spoken  of  are  aqueous  solut  ions,  but  some  gases,  non-aqueous 
solutions,  and  solids  or  melted  solids  are  electrolytes. 

Fdradai/'s  laws  are: 

1.  The   amount   of  any  substance  liberated  by  electrolysis   is   pro- 
portional to  the  quantity  of  electricity  which  has  passed  through   the 
electrolytic  cell.- 

2.  The  amounts  of  different  substances  liberated  by  the  same  quan- 
tity of  electricity  are  proportional  to  their  chemic  equivalent  weights. 

According  to  the  first  law,  t  he  amount  of  chemic  change  is  dependent 
on  the  quantity  of  electricity,  irrespective  of  its  rate  of  flow.  A  current 
of  5  amperes  will  effect  as  great  an  amount  of  chemic  change  in  one 
minute  as  a  current  of  -jV  ampere  in  fifty  minutes.  As  far  as  electrolysis 
is  concerned,  the  coulomb  is  a  more  direct  electric  unit  than  the  ampere. 
The  latter,  the  ampere,  signifies  a  current  at  the  rate  of  one  coulomb  a 
second.  In  electrolysis  one  coulomb  does  a  certain  amount  of  work 
regardless  of  whether  it  takes  a  second  or  a  hundred  seconds  to  do  it. 

The  electrochemic  equivalent  of  a  substance  is  the  weight  of  that 
substance  which  will  be  separated  from  its  chemic  combination  by 
1  coulomb  of  electricity.  The  electrochemic  equivalent  of  silver  is 
0.001  1175  gram. 

Hy  Faraday's  second  law  the  electrochemic  equivalent  of  any  other 
substance  may  be  calculated  from  a  knowledge  ot  the  elertroelu-mic 
equivalent  of  silver  and  the  chemic  equivalents  of  silver  and  the  other 
substance.  The  chemic  equivalents  are  based  upon  the  atomic  weights 
and  the  valences  of  the  substances.  Silver,  for  instance,  has  an  atomic 
weight  of  107.0:-),  and  being  univalent.  its  chemic  equivalent  is  also 
107. 0.'-i.  Oxygen  has  an  atomic  weight  of  Hi.  but  is  divalent,  and  con- 
sequently its  chemic  equivalent  is  S.  The  elect  rochemic  equivalent  ol 
oxygen  is  1()-S(),.  that  of  silver,  or  0.0000X12*:}  gram.  This  is  the 
amount  of  oxygen  liberated  by  each  coulomb  of  electricity  when  water 
or  any  other  compound  of  oxygen  is  elect rolyxed. 

An  atom  or  a  molecule  of  any  substance  is  an  almost  inconceivably 
small  body,  but  the  same  proportions  hold  good  for  measurable  amounts 
of  the  different  substances  when  forming  chemic  compounds.  <  )n<  tjrntn 
<>/  ln/dr<></(  >i.  a  univalent  element  with  an  atomic  weight  of  l.OOs.  will 
combine  with  S  (/rtnns  <>f  nxi/ycn,  a  divalent  substance,  with  an  atomic 
weight  of  Hi,  to  form  water.  Or.  lO.'J.Ui  -:rams  of  lead,  a  divalent 
substance  of  an  atomic  weight  of  20().ni2.  may  replace  1  gram  of  hydrouen 
in  completely  combining  with  X  grams  of  oxygen.  The  gram  equivalent 
of  lead  is,  therefore,  lo:i.  l(i. 

Faraday's  first  and  second  laws  are 
that   tlu1  same  quantity   of  elect  ricin 
equivalent  of  any  .substance. 
be  Oli.dOO  coulombs,  and  is  called  :i  .' 


_' .")•_>  Mi-:nn  AI.  i.i.i:<  TKMITY   AND   KOXTCKN   HAYS 

<  >:.•  faraday  is  the  ammmt  of  electricity  required  to  liberate  one 
cram  equivalent  of  any  substance,  and  is  equal  to  90,000  coulombs. 
1-  i-  equal  tn  the  amount  of  electricity  carried  l>y  a  current  of  1  ampere 
I;,  ',)»;. t'.no  seconds,  or  twenty-six  hours  and  fifty  minutes. 

The  following  are  the  irra m  equivalents,  equal  to  the  number  of 
different  substances  liberated  by  1  faraday,  or  90,000 

1  »f  liV.il  l-()t)S 

:  .in  o'.t.l  10 

_>:'.. 0,">0 

Ml,  is. 070 


Tin'  .  ii  «••  r  icht-n  ic  equivalents  of  the  same  substances,  or  the  number 
•  i  !  >y  1  ct  Mill  mil  i.  are: 

101.:;  \ 

.j^ylo  ''  '"    LOX10X10X10XIOX10X107 

1S71.0 


o  4 


Cations  are  the  hypothetic  charged  panicles  which  travel  through 
the  electrolyte  in  the  direction  of  the  current,  and  are  liberated  at  the 
cathode:  they  include  all  the  metals  and  hydrogen.  An  ions  include 
chlorin,  broinin,  iodin,  fhiorin,  .\<  ).,.  S(  >,.  and  acid  radicles  and  <  )H. 

Klectrolytes  are  otten  aqueous  solutions  of  salt.-,  but  some  other 
substances  are  found  to  be  decomposed,  uniallv  to  a  less  degree. 

An  atom  of  silver  carries  the  same  electric  charge  or  transfers  the 
same  amount  of  electricity  as  an  atom  of  hydrogen. 

Grotthuss'  hypothesis  of  electrolysis  is  that  the  molecules  of  a 
dissolved  compound  form  a  chain,  and  that  under  the  influence  of  the 
electromotive  force  they  exchange  partners  in  such  a  way  as  to  leave  a 
free  atom  of  one  substance  at  one  end  and  of  the  other  substance  at  the 
other.  Thus  in  the  electrolysis  of  hydrochloric  acid  the  molecules  form 
such  a  chain  as  this: 

(H('l)     (H('l)      (H('l)     (HC1), 

but  under  the  influence  of  the  electric  current  this  becomes 
H     (C1H)      (CUD      (C1H)     Cl. 

Clausius'  Theory  of  Electrolysis. — This  is  that  salt  molecules  in 
solution  occasionally  dissociate  into  a  positively  and  a  negatively  charged 
portion,  i.  c.,  positive  and  negative  ions.  The  cations  move  in  a  general 
direction  from  the  anode  to  the  cathode,  while  the  anions  move  in  the 
opposite  direction.  Those  ions  which  reach  the  respective  electrodes 
give  up  their  charge  there,  and  also  form  a  free  mass  of  a  simpler 
substance,  either  as  a  gas  or  as  a  metallic  deposit,  or  as  an  acid  radicle 
combining  with  the  substance  of  the  electrode,  as  the  case  may  be. 
Xot  all  the  cations  or  anions  reach  the  respective  electrodes.  Very 
many  of  them  encounter  oppositely  charged  ions  and  become  neutralized. 
Decomposition  and  recomposition  of  the  molecules  are  continually 
going  on,  with  a  resulting  uniform  drift  of  oppositely  charged  ions 
toward  the  two  electrodes.  This  dissociation,  or  the  formation  of  ions, 
is  not  necessarily  the  result  of  the  electric  current,  but  is  present  whether 
or  not  there  is  any  current.  Their  rnndntt,  however,  is  a  result  of  the 
electromotive  force. 

The  Electron  Theory  of  Electricity.— Observations  upon  elec- 
trolysis in  liquids  and  upon  the  ionixation  of  gases  show  that  the  nega- 
tively charged  particles  in  a  gas  are  only  ,  Jnn  the  size  of  a  hydrogen 
atom.  Positively  charged  bodies  as  small  as  this  are  not  known  to 
occur,  and  so  a  theory  has  arisen  t  hat  t  here  is  only  one  kind  of  elect  ricity. 
This  is  t  he  kind  termed  n<  gatirc,  purelv  by  convention,  and  it  is  assumed 
to  exist  in  unit  charges  or  atoms  of  electricity  called  electrons.  A 
negatively  charged  body  is  one  containing  an  excess  ot  electrons,  a 
positively  charged  bodv.  a  deficit,  and  in  a  neutral  body  the  electrons 
are  in  equilibrium. 

This  theory,  which  is  rapidly  becoming  the  accepted  one,  regards 
electricity  as  consisting  of  material  particle-  a  uTeat  deal  smaller  than 
the  atoms  known  in  chemistry.  Kadi  elect nm  carries  a  charge  of  about 
I  .-'vt  X  1()~"'  coulombs.  It  requires  OX  1(  l"';  electrons  to  carry  one  faraday 
of  electricity.  With  univalent  negative  ions,  such  as  chlorin.  each 
charged  atom  or  ion  has  one  electron.  This  adds  o.ooi  to  the  mass  or 
weight  of  the  atom  of  chlorin.  which  is  :!.").  1  (limes  the  weitrht  of  a 


_>;,l  Mi:nn  \i.  KI.KI  THICITY  AND  KONTCKN   HAYS 

;akes  the  chlorion  weigh  Ho. 401.      The  following 

nl;,   ill;;         ;,  -  iiic    ;-c  ni'  tlic  svmbols  that    have  been   adopted  for 
,-xpn  ~-j:n:  '  aii  atom  of  chlonn  plus  a  negative  charge  equals 

•  i  ivi    .'Morii!  inn: 

Cl     •    0        Cl 

I-,  ,    •    M  Xa  -    vl-        Xa     signifies    lhat    an     atom    of 

*ii  i\  e  charge  equals   a   sodion.  <>r  a  positively  charged 

ion.      A    positive  charge  subtracts  the  weight   of  an  electron 

•  t   nl   an   um-harged  sodium  atom.      The  weight  added  to 

•    ;  [>  in  electrolysis  or  in  a  voltaic   cell  is  exactly  equal   to 

,1  from  the  oppositely  charged  atoms. 

\::  .   ni  i.-  propounded  in   Iss?  the  theory  that  a  salt  whose  solution 

I  p.lyte  becomes  lariielv  or  in  some  cases  completely  dissociated 

•  -;•;•.•  ions  of  one  siibst  ance  and  negative  ions  of  the  ot  her.      This 

irs  as  the  result  of  the  chemic  process  of  solution,  and 

•     •       quire  the  application  of  an  electromotive  force,  though  the 

.    njiverned  h\-  such  a  force  if  it   is  applied.      In  a  voltaic  cell, 

•   ii    .  ier;  p.posit  ive  element  or  t  he  one  which  is  dissolved  by  the  acid 

charged  ions  of  the  metal  are  produced,  while  the  plate  itself 

e-   an   equal   negative  charge.      The  opposite  charges  produced  in 

•,vav  in  thet"    i  elect rodes  are  the  source  of  the  electromotive  force. 

Arrhenius'  Theory.-    This  has  to  do  with  the  solution  pressure  and 

osmotic  pressure  of  substances,  and  their  relation  to  the  degree  of 

•  I)   elect  p  >lvl  e. 

\  -  ilutiou  of  sugar  in  water  may  be  placed  in  a  semiporous  jar  which 
-I'd  except  for  its  connection  with  a  pressure  guage,  the  jar  being 
;  in  an  outer  jar  of  water.  The  "semiporous"  jar  permits  the 

:.  I  mi   not  of  the  dissolved  sugar,  through  its  pores.      It 

•'••  :  ,   •;•  .  for  example,  hv  taking  an  unglaxed  porcelain  jar  filled 

|>hate  of  cop]iei-  and  placed  in  a  jar  containing  a 

->i  im  ferrocvanid.     This  results  in  co])per  ferrocyanid 

:    .:.   the  pores  of  the  jar.  which  gives  the  jar  the  "semi- 

bove  described.      Any  soluble  substance  has  a 

\  pa  rid  :::.•;  occupy  the  whole  of  the  solvent   (the  dissolving 

,;'>•!•  to  a  jar  half  full  of  a  solution  of  sugar,  the  sugar 

•   themselves  through   the  newly   added  water, 

the  entire  quantity  of  water  will  contain  a  sugar 

-tren<£th.      Similarly,    sugar    added    to    a     certain 

iTiiM-  it-eh   uniformly  through  everv  jiortion  of 

'    tin     water   already   contains  some  dissolved 

.'.nli    which    the   Millar   dissolves   diminishes    pro- 

en  t  hat  amount  of  wat  er  will  not 

('In     -oiut  ioi     is  t  hen  said  to  be  saturatetl. 

p:  of  -'i'_r;ir  inside  of  the  semipermeable 

nter:     m  coiiseijiience  i  >\  the  t  eudeucy 

Hsi-ll    thi   niirh    the   lai'gest    possible   amount    of 

"'  [>ass  t  hrotiirh  the  wall  of  the  jar,  t  he  water 

the   seiniporoiis   jar    and    form    a 

I  he  cm  r;i  nee  iii  water  increases 

-    P  L'istep-d    upon  t  he  guage,  and   1  his 

•    in  re  \s  ati  r  mav  enter.      The 


final  pressure  attained  is  that  which  produces  an  equilibrium  between 
the  attraction  impelling  the  water  to  enter  the  jar  containing  the  sugar 
and  t  he  mechanic  pressure  inside  t  he  jar. 

The  apparatus  which  has  just   been  described  is  an  osnwmrtir, 
the  force  exerted  by  a  soluble  substance  in  drawing  the  solvent 
dissolving  liquid  to  itself  is  called  the  osmotic  prasfiiirt    of  the 
substance. 

\"an't  Hoi'f  was  the  discoverer  of  the  fact  that  substances  in  solution 
behave  like  gases,  and  generally  are  governed  bv  the  same  laws.  Just 
as  gas  molecules  distribute  themselves  uniformly  throughout  any 
space  that  is  open  to  them,  so  the  molecules  of  a  soluble  substance 
distribute  themselves  uniformly  through  all  parts  of  the  solvent. 

Boyle's  law  is  that  the  volume  of  the  same  quantity  of  any  gas  varies 
inversely  as  the  pressure  is  generally  applicable  to  dissolved  bodies. 
Their  osmotic  pressure  usually  varies  inversely  as  the  volume  of  liquid 
in  which  they  are  dissolved. 

Avogadro's  law  that  under  similar  conditions  of  temperature  and 
pressure  equal,  volumes  of  all  c/axi'*  c<nil<ti-n  <tju<ii  •number^  <>j  niuhculf *  is 
also  generally  true  of  dissolved  substances. 

"Van't  Hof'f  noted,  however,  certain  exceptions  to  the  application  of 
these  two  laws  in  the  cases  of  soluble  substances,  and  found  that  for  any 
particular  substance;  there  was  a   fixed  and  definite  ratio  between  the 
observed  osmotic  pressure  and  the  osmotic  pressure  calculated  according 
to  the  laws  of  gases.     Van't  Hoff's  factor  is: 
Observed  osmotic  pressure 
Osmotic  pressure  calculated  from  law  of  gases. 

Arrhcnius'  discovery  consisted  in  the  fact  that  the  substances  in 
which  Van't  Hoff's  factor  is  greater  than  one  are  all  electrolytes,  and 
his  theory  offers  the  following  explanation: 

Take  a  solution  of  a  certain  strength  of  some  substance.  K('l, 
for  example,  and  calculate  the  osmotic  pressure  from  Avogadro's  law, 
and  using  the  ordinary  chemic  formula  for  the  molecule.  Now  suppose 

that  out  of  every  100  molecules  S(i  are  dissociated  into  K  and  Cl.  or 
positively  charged  free  particles  of  potassium,  and  negatively  charged 
free  particles  of  chlorin.  The  amount  of  substance  which,  in  the  first 
case  supposed,  would  consist  of  100  free  particles,  each  being  a  molecule 
of  KC1.  would,  in  the  second  case,  which  Arrhenius'  theory  presents  as 

the  actual  condition,  consist  of  14  molecule-  of  K(  '1  and  SO  K  and  Mi  ('] 
(SO  positively  charged  atoms  of  potassium  and  sO  negatively  charged 
atoms  of  chlorin),  or  ISO  free  particles  in  all.  Arrhenius'  theorv  is  that 
these  free  particles  behave  like  iMi  molecules  of  a  gas.  and  that  hence 
t  he  osmotic  pressure  of  such  a  so  hit  ion  should  be  1  .SO  t  lines  the  osmotic 
pressure  calculated  from  the  ordinar  molecular  formula. 


of  a   solution    and  the  osmotic   pressure   calci 

molecular   formula,  we   may   calculate   the    percentage  of 

which  are  dissociated  or  its  decree  of  ionixation. 

The  conductivity  of  a  liquid  is  in  a  sieneral  way  proportionate  t< 
its  degree  of  ionixation.  A  solution  of  cane-sugar  in  water  present: 
practicallv  the  same  actual  osmotic  pressure  as  the  osmotic  pressun 
calculated  from  its  molecular  formula  ( '  ,1 1  ,,<  >,,.  and.  therefore,  accord  in  i 


Mi:i>n  vi.   I.I.M  TKirrrv   AND   KONTCEN   RAYS 


[,,    \:':..'.:.-    ihe-nry.  contains  practically  no  dissociated  molecules  or 
..  ;.  accordingly,  lie  a  non-conductor  of  electricity.     Thu 

.\ci  i  his  t  heory.  there  are  many  cases  ill  "which  {i  sail  becomes 

•,      •     :        •       li-.-ociated    hv     being    merelv    dissolved    111    water.       But 
.    ...  ii -i;  it  ion  i.-  into  ions  or  chargei  I  part  ic  Irs  oi'  two  sii'hst  ances.  and 
-  n,;i\    l>e  ijuiie  ilitTerenl   trom  those  oi  the  separate  sub- 
i-iiiM  Ives.      The  separate  substances,  elements  in  some  cases, 
tiic  charged  particles  or  ions  give  up  their  charge. 
.     _:••;::     similarity    between     the    cliemic    ]>rocesses    and 
.  i't'.'Ci    in  ;in  electrolytic  cell  and  in  a  voltaic  cell,  the  only 
i-"i  nri  il  dit'fi  n  nee  being  that  the  processes  are  reversed.     The  chemic 
nt  in»;  t  he  react  ion  taking  place  while  charging  a  storage- 
means  •  :  a  dynamo  are  simply  reversed  when  t  lie  storage-cell  is 
LT'-d.      At    first    it    is  acting  as  an  electrolytic  cell,  and,  in 
the  second  case,  it    acts  as  a  Voltaic  cell. 

!•:  e  tin  :   case  the  current   is  produced  bv  the  motion  of  cations  in 

anions   in   the  other  direction :  and  tin  currtnt  is  said 

;.,     convention)    to    take    the    direction    of    the    cations.      The 

cations  carrying  a  positive  charge  to  the  cathode  pro- 

d  i<'f-  a  "  c  irreiit  "  in  exactly  t  lie  same  way  as  the  motion  of  the  an  ions 

can"  :•  L:  a  negative  charge  to  the  anode.      (  )ne  motion  might  just  as  well 

:.;-.'  •  d  the  direction  of  the  current  as  the  other,  except  for  the 

:      '  that  in  i  he  very  beginning  the  name  p^A'^nv  had  been  given  to  the 

:    -t;  tic  electricity  which  still  bears  that   name;  and.  of  course, 

the  -.vholc  electric  nomenclature  must   be  harmonious. 

The    Mechanism   of  Electrolysis.     Several   important    facts  have 

h<  •  '.  ":>-•  rved.      The  current  strength  is  the  same  at  every  cross-section 

^I'nple  or  undivided  circuit.      In   the  case  of  a  voltaic  cell  whose 

.'  -  are  connected  bv  an  outside  wire  t  he  same  number  of  amperes 

through  the  win-  and  at  the  surface  of  e  it  her  elect  rode  and 

'  he  electrolyte.      The  current  density,  however,  varies  according 

of  the  cross-section  Jit  any  part  of  t  he  circuit ,  since  the  same 

ertricity    flows   at    each    cross-section    at    the   same   rate. 

true  in   i  he  case  of  an  electrolytic  cell,  and  even  when 

:dc   cells   and    electrolytic   cells   and   simple   conductors   are 

;i  simple  circuit,  /.  <:,  in  series,  not  in  parallel  or  in  shunt. 


1      ' 


cteil  m  series  with  an  electro- 

-ed  into  oxygen  and  hydrogen, 

'   '  '._r  cord~.      I  lie  sa me  current 

n    1  to  be  flowini:  I  hr<  nigh  t  he 


DYNAMIC    KLKCTKICITY 


257 


electrolyte  in  either  voltaic  cell,  through  anv  part  of  the  conducting 
cords,  through  the  galvanometer,  and  through  the  electrolytic  cell. 
Kven  in  the  latter  the  same  current  strength  is  found  in  the  narrow 
column  of  fluid  between  the  electrode  and  the  general  trough  of  fluid, 
and  in  this  larger  mass  of  fluid. 

The  products  of  electrolysis  appear  only  at  the  electrodes.  In  the 
electrolytic  cell  in  Fig.  193  bubbles  of  hydrogen  gas  appear  at  the 
surface  of  one  electrode  and  of  oxygen  gas  at  the  other,  but  no  bubbles 
of  eit  her  gas  arc'  seen  in  t  he  liquid  between  t  he  two  electrodes.  ( 'hemic 
tests  would  not  reveal  t  he  presence  of  tree  oxygen  or  hydrogen  except  at 
the  electrodes,  and  in  the  liquid  and  in  t  he  air-space  above  the  electrodes 
into  which  the  bubbles  of  gas  rise.  A  striking  illustration  of  this  fact 
is  presented  by  the  pole  detector  (p.  2\\\  in  which  the  cm-rent  pa.-.-es 
through  a  liquid  which  contains  a  dissolved  substance  which  is  colored 
red  by  the  free  element  which  is  produced  at  the  negative  electrode. 
The  red  color  is  seen  only  at  the  negative  electrode,  not  at  the  positive 
electrode,  or  in  the  liquid  between  the  two. 

This  means,  according  to  our  accepted  theory,  that  the  ions  of  this 
substance  which  are  diffused  all  through  the  liquid  with  a  general 
motion  from  the  positive  to  the  negative  electrode  present  the  ordinary 
physical  and  chemic  "properties  of  the  substance  only  when  they  give 
up  their  charge  on  reaching  the  negative  electrode.  A  solution  is  used 
in  the  pole  detector  which  does  not  give  a  discoloration  with  the  sub- 
stance liberated  at  the  other  pole. 

Phoresis. — The  passage  of  an  electric  current  through  an  elec- 
trolyte is  accompanied  by  the  transfer  of  one  substance  to  the  positive 
electrode  and  of  the  other  substance  to  the  negative  electrode.  The 
latter  has  become  familiar  in  electrotherapeutics  as  cataphorcsis. 

An  experiment  of  Sir  Humphrey   Davy  demonstrates  at  the  same 
time  the  carrying  property  of  the  electric  current  and  the  fact  that  the 
free  products  are  usually  demonstrable  only  at  the  two  electrodes,  and 
not  in  the  intermediate  fluid.      Three  glasses  are  used  i  !•"!<:.  194'.      The 
glass  a  into  which  dips  the  nega- 
tive electrode  contains  a  solu- 
tion of  sodium  sulphate:  h.  the 
middle  glass,  contains  a  dilute 
svrup  of  violets,  and  r  The  glass 
connected     with     the     positive 
elect  rode,  conl  ains  wat  er.     The 
glasses  n  and  h  are  connected  by 
a  moistened  fibrous  cord  ot  as- 
bestos, and  l>  and  r  are  connected  in  the  same  way.    _  After  the  electric  cur- 
rent has  been  applied  for  a  certain  time,  all  t  he  sodium  sulphate  solut  ion 
will  be  found  to  be  decomposed,  and  the  soi 
into  which  the  negative  electrode  dips,  am 
be  found  to  have  been  carried   thfouj 
of  syrup  of  violets  to  the  glass  c,  into  whit 
The  syrup   of  violets   in    the   middle   glass 
although  it  is  such  a  delicate  reagent  th; 
a  red  color  or  a  drop  of  alkali  a  green  color  in 

The  direction  of  the  phoretic  current  is 
z.  ...  from  the  positive  to  the  negative  electrode  for  bases  and  in  t 
opposite   direction    for   acid    radicles. 
17 


.",s  MIDI.   AI.     i:l.K<  TKlrlTY    AND    KoNTCKN     HAYS 

i-   more  electrolytic  cells    may  lie  connected  in  scries   by  po- 

i-  moi-teiied  cord-.  a>  iii   Fin'.   I'.M.  or  the  liquids  may  be  separated 

.-   earthenware   partitions.      In   either  case  the   series  of 

-    act.-    ;  -  :i  -illirle   electrolytic  cell  of  the   most  ])erfect   type,  for.   as  we 

-  r!i.   tin    products  of  electrolysis  are  separately  collected  in  the 
1     .     i-ll.--     ,'j  ether  these  products  be  gaseous,  solid,  or  liquid. 
The  Human  Body  an  Electrolyte.    The  importance  of  the  subject 
sis  Iii  -  in  tlie  fact  that  the  human  tissues  form  an  electrolyte. 
Mfect>  n]    the  current   are  most  marked   at   the  electrodes,  and  in 
•a-e-  include  visible  chemic  decomposition  and  phoresis. 
I  )eminerali/ed  gelatin  is  electronegative,  and  a  very  slight  addition 
electrolyte  make-  it   electropositive.     Demineralized  gelatin  has 
lingly    -liirht    conductivity,    only    }  U,,lj7^i.    according    to    D'Here,1 
nd  gelatin  may  be  demineraliaed  by  electric  dLilysis. 

Two  or  more  electrolytic  cells  in  series,  but  connected  by  metallic 
.:•  -.  instead  of  a  pop>us  partition  or  moistened  cord,  act  as  separate 
lls,      bach  cell  in  such  a  case  has  its  own  two  electrodes, 
lyte  is  decomposed  into  two  simpler  substances,  without 
e  changes  occurring  in  the  other  cells.     There  is  practically 
the  contents  of  the  different  cells,  and  practically  no 
f   the   contents   of  one   cell   to   another.      The   qualifying 
,  because  even  the  metallic  wires  act   to  a  slight  extent 
.  mid  the  transmission  of  a  current   is  accompanied  by 
ion.-   Ml    metal   and  other  substances  through  the  solid 
ffect    produces  no  perceptible  result   i'1  the  case  of  the 
t  an  electric  current  for  a  few  minutes.      A  case  in  which 
e  a  demonstrable  result  is  the  experiment  of  laying  a  zinc 
M  copper  one.  and  leaving  them  undisturbed  for  months 
t'-  electric   current    g(-nerated   by   the   contact    of  the   two 
;;!.-  i-  a  feeble  one,  but  is  none  the  less  accompanied  by  the 
n-,  and  at  t he  end  of  the  experiment  chemic  analysis  shows 
i  xinc  iii  the  coj)per  di.-k  and  of  copper  in  the  zinc  disk. 
The   Mechanism  of  Conduction  Through  Metals. — According  to 

rtion    of    every    metal    is    normally 
ctrons,    which    are    all    negative,  and    a    residue 
ns    of    the     metal.        These 
ecause   they    are   deficient    in    the 
hey  are  associated  when  in 
lat  ively  fixed  in  posit  ion,  but 
among  the  atoms  of  metal, 
and   a   p'  >sit  ive   impulse   is 
-  Lrat  ive  impulse  at   the  other. 
Iriven  ti  >wa  I'd  the 
ppo.-hc  to 
ci  in.-t  itut 


DYNAMIC  KLK<  TKKITY  250 

Phenomena    at    the    Electrodes   in    an   Electrolytic    Cell.     A.  At 

the  Anode.  —  A  metal  dipped  into  an  electrolyte  becomes  subject  to  1  he 
force  of  osmosis.  The  metallic  ions  have  a  strong  tendency  to  dissolve 
in  the  liquid  if  an  electric  current  is  passing  through  the  metal  toward 
the  liquid.  This  means  that  the  metal  which  forms  the  anode  of  an 
electrolytic  cell  in  many  cases  loses  posit  ivelv  charged  particles  to  the 
electrolyte.  These  are  always  of  one  kind  if  the  anode  is  of  a  simple 
metal,  but  if  it  is  of  an  alloy,  such  as  brass,  the  cations  passing  into  the 
liquid  from  the  anode  may  be  of  one  or  other  metal  composing  the  alloy, 
according  to  circumstances.  This  cationic  action  is  sometimes  the  sole 
means  of  effecting  the  passage  of  the  current  from  the  anode  to  the 
electrolyte.  This  is  the  case  with  the  zinc  electrode  of  a  voltaic  cell, 
where  the  amount  of  current  is  fully  accounted  for  by  the  amount  of 
zinc  dissolved.  This  is  the  effect  produced  in  mercuric  and  other 
cataphoresis  or  anodal  diffusion. 

In  other  cases  very  few  ions  of  the  metal  anode  pass  hit  o  the  electro- 
lyte1, and  The  transmission  of  the  electric  current  is  effected  almost 
entirely  by  the  (lixc/ntrt/i  of  an  ion  K  brought  by  the  electrolyte  to  the 
surface  of  the  anode.  Platinum  electrodes  are  used  when  it  is  desired 
not  to  have  particles  of  the  anode  pass  into  the  electrolyte.  Platinum 
ions  exist,  but  they  are  not  readily  soluble  in  the  usual  electrolytes,  such 
as  the  dilute1  acid  in  a  water  voltameter  or  the  tissues  of  the  human 
body  in  electrolysis  or  galvanoptmcture.  The  current  cannot  be 
carried  from  platinum  to  acidulated  water  by  platinum  cations  to  any 
practical  extent.  The  process  taking  place  at  the  anode  consists  almost 
entirely  in  the  discharge  of  oxygen  anions  resulting  in  the  evolution 
of  free  oxygen  gas  and  the  discharge  of  free  electrons  (negative,  of 
course)  which  enter  the  platinum  anode. 

Exceptional  ways  in  which  the  electric  current  may  pass  into  the 
solution  from  the  anode  are: 

1.  Oxidation  of  a  positive  ion  in  the  electrolyte. 

'2.   Reduction  of  a  negative  ion  in  the  electrolyte. 

1.  When  the  current  is  turned  on  the  change  which  takes  place  at  a 
platinum  anode  immersed   in  a  solution    of  a  ferrous    salt,  under  some 
circumstances,  converts  it    into  a  ferric  salt.     This  contains  more-  highly 
charged  cations  (positively  charged  ions  which  tend  to  travel  through 
the    electrolyte    toward    the    cathode"),   and    consequently   involves   the 
transfer  of  positive  electricity  from  t  he  elect  rode  to  the  electrolyte.    This 
is  done  according  to  the  electron  i  heory  by  the  entrance  oj  free  electrons 
into  the  platinum  anode  from  the  electrolyte. 

2.  On  the  other  hand,   if  a   platinum  anode  is  immersed  in  a  ferro- 
cyanid  solution,  the  passage  of  the  current   produce-  a  change  to  tern- 
cyan  id.  a  negat  ive  ion  of  a  lower  charge.      1  fere  t  here  has  been  a  t  ran.-ter 
of  a  negative  charge   from    the  electrolyte  to   the   anode,   and   this  also 

ae  oi  free  electrons  from  the  elec- 


P>.     At   tin    Catlindt  .      1.   Ther 
In  ordinary  elect  n  iplat  ing  i  he  fre 
lyte  upon   t  he  surface  of  t  he 
lose  their  posit  ive  charge  to  t 
according   to    t  he   elect  r<  >n    i 
negative)  pass  from  the  cath 

'2.   The  forttifltitni  "t  mi  ntt/nn, 
circumstances.     Thus,   n    platimu 


•JliO  Mi:i'!i  Al.    KI.Kt  THICITV    AND    KOXTGEN    HAYS 

Ivte  kept   saturated  with  chlorin  ga-  will  produce  a  certain  number  of 

chiorion-  <  n  aniou-. 

Tlir  other  method-  by  which  the  current  sometimes  passes  from  the 
•     >lyte   tn  tin     cathode  an-  also   t  h"  reverse  of  those  at   the  anode. 

;;.    l>iminuti"ti    of     tlie    positive    charge    on    a    cation    by    chemic 

• .   •  . 

I.    hiciva-e  I'f  the  ii'-irai  ive  charge  mi  an  anion.  by  oxidation. 

Phenomena   Occurring   in   the   Electrolyte. — It    is  not   necessary 

->  ;i    .    •;,.    :  :-  -.  •  re  of  free  electrons  in  the  electrolyte.      There  are 

-   •  .     hers  nf  cations  and  anions  in  the  solution.     These 

ite  directions,  and  the  sum  of  the  electric  charges 

•.-••••:•.;   h\    them   constitutes  the  total  electric  cnrrent.      Ions  have 

•     ;_:<•-   Hi    mobility.      If.    in   a   certain    case,    the   cations   are 

•   r<  :,  times  the  speed  of  the  anions.  then  ten  times  as  much  of 

current  t  hi  ough  the  electrolyte  will  be  made  up  of  a  transfer 

:   :•  •-/.•    charge  by  the  cation.-  as  of  a  negative  charge  carried  by 

':.-      •.:  >ns.      The  current  is  then  said  lobe  mostly  cationic. 

Speed   of   Ionic    Migration. — The   motion   of  the   ions   under  the 
electromotive  force  is.  on  the  \vhole.  a  drifting  movement 
.  '  it  her  electrode.     The  individual  ions  do  not  traverse  the  entire 
lually  increasing  velocity,  as  they  "would  do  if  there 
'    •    constant   electromotive  force  to  be  considered.      On  the 
.  '  In  y  tnovf  a  certain  distance  and  then  collide  with  other  ions 
-    and    lose    their   acquired   velocity.      If   they   collide   with 
el\    charged   ions,   the  charges  on   the  two  are  neutralized,   and 
ce  :ts  ills-  x-iated  inns  temporarily  ceases.     The  effective  mobility 
'-•    velocity  of  the  ions,  including  periods  of  rest,  at  a  poten- 
..•  '  '   o]    1   \-i  h   per  centimeter,  is  in  an  aqueous  solution  for — 


ic  chanties  are  propagated  through  electrolytes 

M'  a.-un  ':.•  nts  have  been  made  by  Sir  Oliver 

anner:      A  irlass  lube  filled  with  jelly  consisting 

chlorid,    and    a   little   phenolphthalein   com- 

Irocliloric  acid.      1'latinum 

tin1  current    pa-seil  from  the  hydrochloric  acid 
it  ion  (it  h  vdi'i  igen  cat  urns  into 


•  '  '  -    in     '  he    eli  ct  rolyte.       The 
".(.  ill    be    remembered. 

of  water, 

•  '  inn.      After  t  he  flow 
'''•••  '  he  sulphuric 

delicate    test    for   acids 


DYNAMIC     KLKCTIUCITY  201 

the  sodium  chlorid  jelly  the  hydrogen  ions  collide  with  chlorin  ions  which 
are  present  to  form  hydrochloric  acid  molecules  at  different  points  in  the 
electrolyte  as  the  hydrogen  ions  advance.  The  free  hydrochloric  acid 
thus  produced  decolorizes  the  phenolpht  halein.  In  the  other  experiment 
the  ions  of  the  sulphuric  acid  radicle  advance  through  the  electrolytes  in 
the  three1  jars  without  forming  molecules  of  free  sulphuric  acid  until  the 
ions  reach  the  anode1  and  lose  their  electric  charge'.  The  ions  which  have1 
collieled  with  oppositely  charged  ions  have  formed  free  molecules  of  a  salt 
ne>t  of  an  acid  e>r  alkali  in  the  intermediate  portions  of  the-  electrolyte. 
Hence  the  delicate  reagent  for  free  acid  or  free  alkali  has  not  been  affected. 

The  Velocity  of  the  Ions  in  an  Electrolyte  and  in  Gases,  and 
of  Electrons  in  Metals.  The  figures  found  by  the  method  described 
above'  are  astonishingly  small  compared  with  the  velocity  of  the  ions 
of  a  gas — 20,000  miles  a  second  in  an  ./'-ray  tube,  or,  compared  with  the 
rate  of  transmission  of  elect  rich  v  bv  metals,  LNs.ooo  miles  a  second. 
In  the  case>  of  metals,  however,  the  transmission  is  effected  not  bv  ionic- 
migration,  but  by  the  migration  of  free  electrons. 

Conduction  by  Fused  Salts  and  by  Metallic  Oxids. — Salts  and 
metallic  oxids  at  ordinary  temperatures  are  very  poor  conductors  of 
electricity.  The  former  become  good  conductors  if  they  are  melted 
by  heat,  and  it  is  very  readily  demonstrated  that  their  conduction  is 
electrolytic.  In  fact,  this  is  the  method  adopted  in  obtaining  some  of 
the  rarer  metals.  Magnesium  may  be  obtained  in  this  wav.  An 
ordinary  clay  tobacco-pipe  with  an  iron  wire  from  the  negative  pole  of 
the  battery  passing  into  it  through  the  stem  is  filled  with  a  mixture  of 
chlorid  of  potassium  and  e-hlorid  of  magnesium.  The  salts  are  fused 
by  the  heat  of  a  Bunsen  burner,  and  a  graphite  anode  from  the  battery 
is  dipped  into  the1  melted  mass.  The  conduction  is  excellent,  and  is 
accompanied  by  the  liberation  of  chlorin  gas  at  the  anode,  and  of 
me-lte'd  metallic  magnesium  at  the  iron  cathode  in  the  bowl  of  the  pipe. 

The  comparatively  infusible  metallic  oxids.  such  as  the  oxid  of 
zirconium,  are  made  use  of  in  the  Xernst  lamp.  There  is  a  "heater 
coil"  of  platinum  wire  through  which  the  electric  current  is  first  pa>sed. 
and  in  which  sufficient  heat  is  produced  by  ohmic  resistance  to  bring  t  he 
"glower,"  consisting  of  metallic  oxids.  to  a  temperature  at  which  it 
becomes  a  conductor  of  electricity.  The  current  is  such  a  powerful 
one  as  to  heat  the  "glower"  to  bri 
advanced  for  believing  t  hat 
case  of  oxids  of  t  he  met  als 
incandescence  is  electrolvtic  ; 
ret  ically.  if  t  he  conduct  ion  w 
in  met  als.  the  suhst  ance  sin  ml 
are  t  transparent .  A  st  ronger  re; 
of  a  mixture  of  the  oxids  of  tw 
t  hues  found  to  be  im  >re  concent  I1; 

The    Passage    of    Electricity 

manliest  1  v  due  to  a  migrat  ii  <\\ 

ductor,  but    the  fact    that    such   a 

even  with  very  weak  current.-,  war 

piece  of  gold  and  a  piece  i  .1   n  >ppi 

The1  weak  current    pn  idliced  by  t  In 

during  this  long  time  caused  a  sufficient  migration  of  ions  in  e; 

lion   thoroughly  to  saturate  the  gold  with  copper  and  the  copper  with 

gold.     The  ioni/ation  of  a  metal  thr  >ugli  v,i,;r;i  electricin   ;-  couducti  d 


•_',,_'  \1!.1>1(    \1.    U.l.i' I'KiriTY    AND    KOXTCiEN    HAYS 

h:is  important  therapeutic  list's  and  so  docs  the  effect  upon  the  tissues 

.  :ini;:i:il   body.     These  are  essentially   li()Ui\l,   and   an   important 

:    .-lee:  rot  herapeutics   is  concerned  with  the  changes  pro- 

is.-a.m-  i»f  an  electric  current.     This  will  be  con- 

;    ir:v  is  ;  iw;  \>  ::."iv  or  less  resistance  to  the  passage  ot   a  current 

and  this  depends  partly  on  the  nature  of  the  sub- 

•    .    •,  its  diameter   and   length.     Substances  which 

,  •  .-.     ic;  ,  v  .  •'  :  •'•/'.    verv  well  are  called  conductors;  t  he  metals  are  con- 

,;•;    •  ,;•-.      >o:  han  others.     Substances  which  conduct  electricity 

•  ..••.    :  iv  used   to  prevent  its  escape  from  conductors  are 

inductors   or   insulators — glass,    rubber,    and   gutta-percha 


THE  THERMAL  EFFECT  OF  THE  ELECTRIC  CURRENT 

T'  nl  of  electricity  passing  through  a  good  conductor,  stich  as  a 

•-    the   coiiduct(»r   to    a   certain   extent.      This  effect    is 

.  •  :_••''.-  ::.  case  of  a  cupper  wire  to  the  production  of  heat  by 

i:i  motion,   and   in   the  case  of  a  short   straight   wire 

.   any   other  wire  or   magnet    or   magnetizable  body, 

lost   bv  the  current   in  passing  through  the  wire 

,'hii-h     is   converted    into   heat.       The    conditions   expressed    in 

•nee   show  that    no   work    is    being  done    by  the    current 

•  •  simple  overcoming  ot'  nhniic  or  frictional  resistance  in  the 

-,  'ii   of   power   through   the   wire.      In   a   case  of  this   kind  the 

o]   •.•••;•    produced   depends  upon   two  ijiiantit  ies:   the  resistance 

•asured    in   ohms   and   the  strength   of   the   current 

The    amount    of    heat     is    expressed    in    grani- 

-  iltiring  to  raise  the  temperature  of  1  gram  of  water 

.  la  t  ions  give  the  amount  of  heat  generated  in  one 

;  cm  ('  ampere.-,,  with  K  volts,  through  a  resistance 


the  wire   wijl    be   raised   will   be  greatest, 

'.»•;:.'  of  heat   is  concentrated  in  a  short  length  of 

i  he  ci  >nd it  ion >  prevent  t  he  rapid  radiation  of 

•'"!'.      In    n-ifai'd    lo    ilie    last    point,    an    inclosed 

~   ii"'1''!'  than   the  same   i(lentii-al   motor  without 

i  ii'    '  :  -'   fad   is  found  in  t  he  incandescent  lamp. 

•  '  '   I>P  -i  '.'  a  resistance  ol  '_'.")()  ohms,  and  become 

a   current    of    ',   ampere;  while  the  same   \ 

:>'"  '.'    win  •    .' .,   inch   in   diameter  and 

•  unti-1    t  he        i    ,     i        -tatice  and    irenei'at  e   t  he 

'     in     a     -ecutid,     1  ):i'     wit  hoiil     ;i     |iercep1  ible 

I '     I.-H-T  ,     •     thi    case  oi    |'i|   inch  ci  ip])ci'  wire, 

'      '   even   as   much   as 

-'ill   n<  it    pr<  iduce  a  maximum  elevat  ion 


DYNAMIC     KLKCTKICITY  26:3 

(('    =    .),  ;ind  in  therapeutic  applications  the  resistance  is  greatest  with 

a  small  area  of  contact  between  the  electrode  and  the  body.  A  sponge 
electrode  with  a  surface  of  \  square  inches  may,  for  example,  be  applied 
to  the  nape  of  the  neck,  and  the  other  electrode  consist  of  a  silver 
probe  making  a  contact  with  the  mucous  membrane  of  the  gum 
over  an  area  of  perhaps  only  .',,  square  inch.  The  same  current  is 
passing  at  both  places,  and  the  amount  of  heat  produced  at  each  elec- 
trode is  proportional  to  the  resistance  at  that  place  of  contact.  There 
would  be  no  perceptible  warmth  at  the  sponge  electrode  with  a  current 
of  1  or  2  milliamperes,  while  at  the  electrode  applied  to  the  gums, 
where  there  is  a  great  many  times  more  resistance,  the  heat  would  be 
very  disagreeable. 

The  factor  of  heat  at  the  contact  surfaces  between  the  body  and 
the  electrodes  probably  has  something  to  do  with  the  reduction  in 
resistance  which  occurs  after  a  short  period  of  flow  of  the  continuous 
current.  This  lessened  resistance  takes  place  when  the  electrodes  are 
applied  to  a  wet  thread  or  to  a  nerve  which  is  apparently  homogeneous. 
It  can  be  demonstrated  by  the  VVheatstone  bridge. 

The  production  of  a  large  amount  of  heat  by  electricity  involves 
two  factors:  the  flow  of  a  heavy  current  through  great  resistance.  A 
marked  rise  in  temperature  is  obtained  when  a  large  amount  of  heat 
is  generated  in  a  small  portion  of  matter.  The  human  body  is  not 
(^specially  favorable  as  an  object  in  which  to  develop  a  high  temperature 
by  electric  currents.  The  resistance1  of  the  body  is  so  great  that  the 
strength  of  the  current  transmitted  is  very  small  indeed  in  comparison 
with  metallic  conductors.  And  the  small  amount  of  heat  which  is 
generated  is  quickly  removed  from  the  point  of  contact,  partly  by  the 
circulation  of  the  blood  and  lymph  and  partly  by  ordinary  conduction. 
High-frequency  currents  are  an  effective  and  often  very  beneficial 
means  of  producing  a  large  amount  of  heat  by  their  passage  through 
the  human  body. 

The  fact  that  a  boy's  arm  and  leg  may  have  to  be  amputated  in 
consequence  of  circulatory  disturbances  from  contact  with  a  wire  carry- 
ing 6600  volts  and  without  any  burn  is  very  striking. 

The  heat  generated  by  ohmic  resistance  to  the  passage  of  an  electric 
current  is  utili/ed  in  electrotherapeutics  especially  in  the  following 
ways:  first,  in  making  warm  or  hot  compresses;  second,  for  cautery: 
third,  for  the  diagnostic  and  therapeutic  application  of  light  and 
radiant  heat.  It  is  also  the  ba>is  of  the  hoi  wire  milliamperemeter 
(see  page  174). 

The   galuanocautcry   applied    for   surgical    operation    is   an    entirely 
different    matter.     The    heat    is    not    produced    by    the    passage    of    an 
electric  current    through   the  patient'-  body,  but    through  a  metal   wire 
or  strip  which  lias  a   resistance   which   though   considerable  allows  ihe 
passage  of  a  very  heavy  current.     The  resistance  is  a  great   deal  les> 
and  the  current    a  great    deal   stronger  than    i-  ever  the   case   with  the 
human  body.     The  large  amount  of  heat  which  is  generated  is  produced 
in  a  very  small  mass  of  metal,  which  is  accordingly  raised 
white   heat.      It    is   the   hot    metal    which    cauterizes   the   fl 
elect  ric  current . 

Reaud's  Electric  Thermostat.     Thi-   is  an   example  of  th 


lUi'Al.     l.l.Kl  TKirlTY    AND    KONTGKX    KAYS 


[i    consists  of  an   hermetically  sealed  glass  tube  of  a  U  shape,  partly 
tilled  with  mercury.     The  upper  part  of  llic  left  limb  contains  rarefied 
hydrogen  i:a>.  whi'rii  l.y  its  pressure  maintains  the  mercury  at  a  certain 
level,   leavini:  a   vacuum  at   the  top  of  the  other  limb.     A  leading-in 
uuv   fi-i.in   '  tic  elect  ric-lidit    wire  reaches  the  level  of  the  nuTcury  in 
it,  -  tube,  and  Hi*'  current   is  transmitted  through  the  mercury  to  the 
leadinir-in    win-,    through    the   heater  //,   and   thus   to   the  other 
Tlic  whole  apparatus  is  placed  inside  the  bacterial 
hamber,  or  whatever  space  is  to  be  heated  to  a  uniform  tem- 
.      It'  the  temperature  rises  beyond  a  certain  point,  the  hydrogen 
and  depresses  the  level  of  the  mercury  in  that  arm  of  the 
uch  an  extent  as  to  break  the  contact  with  the  leading-in  wire 
of;'  the  electric  current.     The  thermostat  may  be  adjusted  for 


any  desired  temperature  by  adding  mercury  stored  in  a  little  side  tube 

NI  that  in  the  mam  tube,  or  by  pouring  some  out  of  the1  main  tube  into 

•  ibe.      A  -nil  finer  adjustment   is  made  by  inclining  the  tube 

n<i  the  mercurial  pressure  by  lessening  the  difference  in  level 

ii  the  mercury  in  the  two  arms  of  the  tube. 

The  Temperature  Changes  in  Different  Batteries.— These  are  not 

to   the   ohmic   resistance   alone,  but   may  be  influenced  by 

•    cha iiL!e-    \vhich    accompany    the    passage    of    the    current 

medium.      A  gravity  cell,  for  instance,  cools  as  a  result   of 

The  -a me  is  t  rue  of  a  1  )aniell  cell  and  of  a  storage- 

iiator  during  it-  di-charge.      The  Daniell  cell  transforms 

j;,    l"-t    by  it-  materials  dui'ing  the  operation  of  the 

'•   eneru'v.   and   al-o  about     1    per  cent.   more.      This 

1  ' '_  Y   produced   i-  abstracted  from  the  latent   heat   of 

1  hi  re  fore,  cooled  a-  a  whole.      It  s  y.\\\c  pole  becomes 

the  contrarv.  transforms  only  71  per  cent,  of  the 

i  into  elect  ric  eneru'y.  t  he  remaining  2C>  ]>er  cent . 

A    cell    of    thi-    t\'pe    becomes   decidedly 


Peltier's    Gro- 


elect ric  current    upon   t  he  wire  of  elect  ric 

irreat  pract  ical  importance  ('see  page  222). 

'    -  ;    /.'.."""/    "/    i'Ju-lricilii.-    \\'hen    a    bar 

bar  oi    bi-mut  h   and   1  he   negat  ive   pole   is 

ace  ( >j  union  i-  cooled  and  it  is  even 

1  -.      I  lever-ing  t  he  current  produces 

d  ion. 


DYNAMIC     KLKCTKK'ITY  205 

The  Temperature  Changes  Produced  by  the  Passage  of  a  Current 
Through  Different  Electrolytes  Outside  of  the  Battery  Itself.  - 

These  vary  just  as  much  as  do  those  in  the  fluids  of  a  battery  in  opera- 
tion. There  is  always  a  certain  amount  of  heat  due  to  the  ohmic  resist- 
ance of  the  liquid.  '1  his  may  be  augmented  or  diminished  by  the 
thermal  effect  of  the  chemic  change  induced  in  the  fluid  by  the  passage 
of  t  he  current .  Placing  a  1  )aniell  cell  in  t  he  circuit  of  a  powerful  bat  t  ery 
which  sends  a  current  through  the  cell  in  a  direction  opposite  to  that 
of  the  current  which  it  tends  to  generate,  we  should  reverse  the  chemic 
processes  which  normally  take  place  in  a  Daniell  cell.  The  thermal 
effect  is  also  reversed,  and  the  cell  becomes  hotter  instead  of  cooler. 

The  ordinary  process  of  charging  an  accumulator  or  storage-cell  by 
sending  a  dynamo  current  through  it  in  a  reverse  direction  also  reverses 
the  thermal  effect  upon  the  cell.  With  the  usual  strength  of  acid  a 
storage-cell  cools  slightly  on  discharge,  and  is  warmed  slightly  when 
being  charged  by  a  current  sent  through  it  in  the  reverse  direction. 
Generally  speaking,  the  thermal  effect  of  the  chemic  change  from  passing 
a  current  through  a  liquid  is  to  produce  heat  if  the  chemic  reaction  is 
such  as  would  ordinarily  do  so.  and  to  produce  a  cooling  effect  if  the 
chemic  reaction  indicates  that  heat  is  rendered  latent. 

The  Heat  of  lonization.-- An  electrochemie  equivalent  of  any 
substance  causes  either  the  absorption  or  the  liberation  of  a  certain 
number  of  joules  or  heat  units  when  it  becomes  positively  or  negatively 
ionized.  In  the  cases  in  which  heat  is  absorbed  at  the  pole  where  a  cer- 
tain ion  is  produced,  this  usually  means  that  work  must  be  done  in  order 
to  cause  the  substance  to  enter  the  ionic  state.  When  this  is  the  case, 
it  will  usually  be  found  that  heat  is  liberated  when  the  substance  leaves 
the  ionic  state.  Topper  is  such  a  substance,  and  its  heat  ot  iom/aiion 
is  +',]~,'200.  Zinc  behaves  in  the  opposite  way:  it  takes  work  to  brim: 
it  out  of  the  ionic  state,  heat  being  rendered  latent  and  the  temperature 
falling  at  the  polo  whore  this  is  taking  place.  I  nder  the  conditions 
present  at  the  pole  where  zinc  ions  are  produced  the  temperature  rises 
because  heat  is  liberated.  In  entering  the  ionic  state  zinc  actually 
performs  work  in  heating  up  the  surrounding  medium.  Its  heat  ot 
ionization  is  — 0(,),5(JU.  This  means  that  one  electrochemie  equivalent 
of  zinc  in  entering  the  ionic  state  loses  lid. 501)  joules  of  energy  in  the 
form  of  heat. 

The  heating  of  liquids  (electrolytes  or  not)  by  ohmic  resistance  is 
one  of  the  disadvantage's  of  the  liquid  interrupters  and  rheostats  used 
in  electrotherapy. 

Kxamples  from  outside  the  domain  of  electricity  illustrate  the 
subject  of  latent  heat.  Salt  and  ice  mixed  together  have  a  strung 
tendency  to  form  a  solution  of  salt  in  water,  and  this  is  accompanied  by 
the  absorption  of  a  large  amount  of  latent  heat.  Such  a  mixture  forms 
a  freezing  mixture.  Water  and  sulphuric  acid  have  an  equally  strong 
tendency  to  mix  and  form  a  solution  of  sulphuric  acid,  but  in  this  case 
thi'  process  is  accompanied  by  the  liber 

Anvthing  like  a  complete  discussio 
would  carrv  us  too  far  into  the  dotnaii 
It  may  be  added,  however,  that  the  t"i' 
be  those  which  produce  electromotive  lore 

The  Degree  of  lonization  May  be  Determined  by  Cryoscopy.- 
Raoult's  discovery   that    the   free/ing-point  of  a  solution   depends  upon 
the  number  of  molecules   held   in   solut  ion  was  immediately  followed  by 


•_V,t,  Ml  Kit  AI.    KI.KCTHICITV    AM)    ROXTOEN    RAYS 

li-covery  tiiat   -olution-  of  -alt-  and  sonic  other  compounds  gave 

PI  -  .'•-  corresponding  i.i  ;i  greater  number  oi  molecules  than  would  he 

ir    ciiemic    formula-.        1  his    has    hccn    explained    hy 

:;'r;s  "ii   '  :-  thei-rv  of  dissociation  of  ions.      He  supposes  that  in 

.•imr-p"i:it  depends  upon  the  nuniher  of  dissolved 

Pericles    (either   i-niire    molecules   or   dissociated    ions    formed    hy    the 

ii    i.]    •   .  ;••••;!.•-'.     \\  i-    inav    then    say    that    one   gram-particle1 

i  i:  .-•        '.  i  if    :    -::  i  ,-i:  "leciile     dissolved  in  one  liter  lowers  the  frcozing- 

|.s.~i  !  i  'i  i    (  '.     The  numlier  of  decrees  that    the   freezing-point  is 

.    i.    divid    I  b\    l.s.")  1  1  )(>'('.,  will  give  the  number  (X)  ol  gram- 

-  icl,  -  d!->olved   in   a  liter  of  the  liquid: 


'i  he  r:iii   In  r  thus  f"unil  \vill  he  the  numher  of  gram-particles,  both 

1'-.-    and    dissociated    inns   formed    by    split-up    molecules. 

Tii"  '         ;>er  "f  ^!-am-molccuIes.  X1  in  the  substance  is  known  i'ro'm  its 

i:.  .      and  the  amount   or  weight   of  the  substance  which 

".-••:    .:.    making   the  solution.      The  number  of  gram-ions   is 

•  in  iber  ol  gram-particles  (X)  minus  the  number  of  «;ram- 

.,-     \"    . 

:.-  number  oi  gram-ions  is  made  up  of  negative  and  positive  ions: 

one  ot  each  polarity  for  each  molecule  which  is  broken  up, 

me    molecules   split    up   into   a   greater   number   of   ions.      A 

Iphate   of    copper   M'uSOj    splits  up   into   two   ions—  a 

:  |»er  i'»n  f('u)  and  a  negative  sul])hion  (.SO,). 

he  number  oi   molecules  placed  in  the  liquid  and  '/  is  the 
liss'  iciat  ion,    t  hen  - 

i.  N  '  tin  ilecnlcs  are  dissociated. 

N  :      '/  -\  !  Jin  ileciiles  are  intact  . 

.    ''"i  molecule  yields  _'  ions,  there  will  be  — 

''2  "-  X1  ions. 

in  solution  X1  -   '/  X1  molecules  and  2  «  X1  ions,  and 
il  '  i  the  number  of  particles  found  by  cryoscopy  from 

:    Uftoti   t  he  freezing-point  . 
-  :  '•'  'ill  :  i:ives  '/.  the  coefficient  of  dissociation: 


the  c 

i  of  hy.  In  m 

liy  it  -    vnlcncc  nr   i  lie    nuinlicr 
ifc  i  if  i  >r  coinliinr  \\-it  I:. 
l  iMnncc,   ('it  her  siin]ilc  or  com- 


1  i|ili\  ;tleii1    of    the    Mil»t:mre    to 


il  -olut  ion  of  |i(it;i--iutn  dilorid 


nn:il    -ol 


'  '     if  ii  -iiliMam-e.  and  i-  a  quun 

'    '  •\pre-.-ed    ill    LM'alll-. 

',]'•  <  T  di— ociateil   comlit  ion 

\:.  i~. 
'ion    i-    e,  |iial    to   the  .-11  II  I   of 


DYNAMIC    KLKCTUICITY  207 

The  following  is  a  concrete  example.  A  decinormal  solution  of 
CuSO,,  or  one  in  which  0. 10  gram-molecule  (!.">.!)  grams  bv  weight)  of 
CuSOj  is  dissolved  in  1  liter  of  water  is  found  to  have  had  its  free/ing- 
point  lowered  0.2.'$ °  C.  by  the  addition  of  this  amount  of  CuSO,.  The 
numl)er  of  gram-particles  calculated  from  the  fact  that  1  gram  partu-li- 
in  a  liter  lowers  the  free/ing-point  l.s.VC.  is  found  to  be  0.12132. 
Hence — 

(I    !•>.!••!       M    ]() 

0.213. 

A  calculation  based  upon  the  freezing-point  shows  that,  in  a  decinormal 
solution  of  CuSO.,,  24  per  cent,  of  the  molecules  become  dissociated  into 
ions  in  the  mere  process  of  entering  into  solution.  This  agrees  very 
closely  with  the  calculation  based  upon  the  conductibility  of  the 
solution. 

Osmotic  pressure,  freezing-points,  and  electric  conductivity  are  all 
determined  by  the  degree  of  ioni/ation. 

Observations  by  .Maillard.1  Loeb.-  Paul  and  Krfmig:!  lead  to  the 
belief  that  the  ions  in  any  solution  are  the  active  agents  in  any  effect 
upon  living  tissues.  The  effect  of  antiseptics  is  due.  according  to 
Paul  and  Kronig.  practically  entirely  to  the  ions.  The  degree  of  umi/.a- 
tion  of  a  metal,  as  in  a  solution  of  bichlorid  of  mercury,  may  be  reduced 
by  adding  to  the  solution  ions  of  some  other  metal  with  the  same  anum 
(XaCl  per  ex.),  and  if  the  latter  are  non-toxic,  the  toxicity  of  the 
solution  will  be  reduced.  An  experiment  was  made  with  anthrax 
culture  smears  dipped  in  a  solution  containing  1  gram-molecule  of 
bichlorid  of  mercury  (this  being  270  grams  in  weight)  in  Hi  liters  of 
water,  and  the  number  of  spores  which  survived  after  an  immersion  of 
six  minutes  was  found  to  be  only  eight.  Hut  if  1  gram-molecule  of 
sodium  chlorid,  XaCl  (weighing  ~>s  grams),  was  added.  32  spores  sur- 
vived, and  the  culture  showed  32  colonies,  \\ith  two  gram-molecules 
of  sodium  chlorid  the  number  of  colonies  was  124:  with  3.  it  was  2S4 : 
and  with  10,  it  was  10S7.  The  strength  of  the  mercurial  solution  was 
the  same  in  each  case. 

The.  absorption  of  moisture  and  the  interchange  of  substances  in 
solution  through  organic  tissues  which  lorin  the  basis  ot  animal  and 
vegetable  life  are  all  dependent  upon  the  number  and  properties  of  ions. 

The  theory  that  all  life  is  but  a  manifestation  of  electricity  is. 
therefore,  not  at  all  an  impossible  one.  The  further  theory  that  all 
matter  is  of  but  one  substance,  either  electricity  or  variously  modified 
by  electricity,  is  one  of  the  picturesque  possibilities  of  the  future. 

'Journal  <lc  Physiologic  H  <!<•  Pathologic.   IS'.t'.l,  vol.  i.  p.  ti/il. 
'-'.-  \rchiv.  f.  cr,.<.'  Phv-ioL   ISilS,  vol.  lv\,  p.  1. 
3Zcit.  f.  physikal.  Chemit-,  is«n>. 


ELECTRICITY   OCCURRING   IN   ANIMALS    AND    PLANTS 

.  .     ,  _  p,it  'Mini    between    portions  "1    the    surlacc    oi 

\-:iich    an1  so   vvnerally   present    arc  seldom  as  great 

lie  torpedo.      They  generally  require  special 

•    .  .;   detection,  but   it   is  none  the  les.-  probable  thai  they 

i;    pnrtance.       Kledricity     is    (  levelo]  >ei  1    especially    ill    the 

•till     •  ssues.  notably   the  nerves  and  muscles.     1  he 

•    :,  •    .  among  many  other  structures,  manifest  it. 

/'/'   ,  •.     ;;     Brazilian     plant     said    t<>    have    been    lately 

,    [•(•rlain   electric   properties,  and  the  charge 

b\    contacl   with  ii   i.-  claimed  to  be  equal  to  that  oi 

•       \),.'.  ie] 

Mr.-nenil    law    noveming    the    difference    in    potential    between 
•  -   ,:  •;.,.     ,   ••  ;/"»/,  i>  i  ha  .1  it  develops  only  when  there 

;;r'f,   ;-,.;     •(.    ,    '•;..    ['    ;\    tile    HalUl'e   or    111    1  lie    acllVll  V    of    the    cheillic    ]  )1'O- 

•,  in    the   t\vn   ivLri"';-.      \\'hen  there  is  a  difference  in 

•        •    .•  •    •_'  ,;i    '  here  [H'ocesses  of  decomposition  arc  in  excess  is  nejia- 

•  .  ••.:•  :•,  •'_:'_  in  \vhere  synthetic  processes  are  in  excess.      It  both  are 

•  •  -     .•  |i  isition,   the  one  at    \vhich  l  he  process  is  most   active 

•  i  tiii     iiher.      And  ::  both  are  regions  of  synthesis,  the  least 
.     >   ••-'•'  '.-.  ••   to   tin-  other. 

!  :..  ;•••  '.  ;•'       un    ;"  twecii  the  electric  potential  at  the  two  ends 

•  JL'.    •:.'':.•:•    fi-l't  ili/ed    or    imt.       Ida    Hyde1    ha-    tested    this    l>y 

•    •    •    i-apillnrv  electrometer,   i  he  (lit'fcrence  in  potential  in  the 

-  •  •_'_'  .'•.'.•••  ;i-  '  'j'   ;   -  d'-\'elopmelit    progresses.       In  Some  other  eggs 

:   1    .:    ;  .    ,  '   stages  of  scginent  at  ion  cause  rhythmic 

iwer.-al-  of  the  direction  of  the  cui'i'ent.      The  sources 

i-  an     anabolic  ;  ine  changes  in  t  he  chromatic: 

.  changes  in  t  his  mass  in  act  ivity. 

v;-c(  »;;  \-    and    -'i  rl  ace   ten>ion. 


ent    par'  S  of   t  lie   li\'!!;Lr    b'  idv.        I;l'i  Ull 

•    ••        i!     •      o'  he]     '.  .'  •    ;     ;ict  ivit  '      elect  1'olnol  i\'e    fi  il'CC 

1      i>    a     '  ef\      !  '   M  >V    <••  induct  i  if,    (  ipposite 

'     d  if  the  sill-face.     Ifed- 


KLKCTKICITY     ( )(  ( f  HRI  N(  i     IN     ANIMALS    AND     PLANTS  269 

that  the  current  of  demarcation  was  verv  much  increased.  The  infer- 
ence was  that  activity  of  the  spinal  ganglionic  cells  is  accompanied  bv 
electric  phenomena  of  the  nerve-trunk. 

Electric  Currents  in  the  Skin.  Skin  may  be  removed  from  the 
body  and  still  retain  vital  proper!  ies,  as  shown  bv  its  survival  and  growth 
when  used  in  skin-grafting.  As  long  as  the  skin  is  fresh  and  possesses 
vitality,  it  may  be  shown  by  appropriate  electrodes  and  meters  to 
possess  electric  properties.  A  current  will  generally  pass  from  an 
electrode  applied  to  the  inner  surface  of  a  piece  of  skin  through  a  con- 
ducting wire  and  meter  to  an  electrode  applied  to  the  outer  surface. 
This  may  be  called  the  current  of  rest,  and  in  the  case  of  a  piece  of  skin 
freshly  removed  from  the  bodv,  the  internal  surface  is  usuallv  positive. 

it  is  necessary  to  have  non-polari/able  electrodes,  and  to  be  sure 
that  the  results  actually  indicate  a  difference  in  potential  between  tin- 
two  surfaces  of  the  skin.  Without  anv  special  precautions  it  would 
be  easy  to  have  an  electric  current  produced  bv  a  difference  in  the 
degree  or  kind  of  action  upon  the  two  electrodes  bv  a  difference  in  them 
or  by  the  difference  in  the  chemic  composition  of  the  moisture  upon  the 
external  and  internal  surfaces  of  the  skin.  In  other  words,  the  skin 
and  the  two  electrodes  might  form  a  miniature  voltaic  cell  unless 
precautions  were  taken  to  prevent  such  an  effect. 

Current*  Produced  b;/  Contact  of  tin  I nn<  r  and  ()/dir  Surfaci*  of  th< 
Skin  with  Saline  Solution*.—-  These  may  be  detected  by  the  same 
method  as  that  used  by  Chano/,  in  the  case  of  acid  solutions. 
A  piece  of  skin  is  fastened  over  the  end  of  a  tube  filled  wit  h  the  solution, 
and  dipped  into  another  filled  with  a  precisely  similar  solution.  An 
electric  current  will  often  flow  through  suitable  electrodes  and  conducting 
wires  passing  from  the  liquid  in  one  tube  to  that  in  the  other.  '1  hese 
currents  were  one  of  the  early  discoveries  in  elect  rophysiology  „  and  have 
been  experimented  upon  by  DuBois-lleymond.  IMS;  Rosenthal.  l^b'-l: 
Roeber;  Kndemann:  Hermann:  Bach;  Oehler:  Bayliss:  Bradford: 
Reid;  Tallport;  Waller,  1  <)<)!. 

Current*  Produced  h*/  Contact  <n  tin  Inn>r  and  ()nt<r  Snrtaci*  <>t 
the  Skin  with  Acid  Solution*.  Chaimz'*  Ob*<  rmtitnis.  An  experiment 
by  Chanoz1  illustrates  the  method  of  detecting  bioelectric  currents  and 

or  dead  skin 


lei  er,   is  i  >pen  at   one  en. 


band.  Both  ends  of  the  tube  dip  into  vessels  of  the  solution  t< 
tested  and  the  tube  is  also  completely  tilled  with  the  same  solution. 
Kach  of  the  outer  vessels  is  connected  by  in ipolarix.able  electrodes,  zinc  in 
a  solution  of  sulphate  of  zinc,  with  Lipniann's  capillary  electrometer. 

l  i ven ess  and  -mail  electric  capacity, 
i  by  two   \Yeston  cells,  i-  used  for 
determining   the   difference    in    voltage   without    any   calculation. 

The  piece  of  skin  is  taken  from  a  frog  which  has  ju-t  been  killed, 
and  the  experiment  performed  so  quickl/  that  the  current  is  teste,] 
in  one  and  one-half  minutes  after  the  incision  has  been  made. 

The  experiment  is  made  to  determine  the  difference  in  potential 
between  the  outer  and  inner  surfaces  ol  skin,  when  both  are  exposed 
to  a  solution  of  the  same  material  and  tin  strength. 

.-,  .Juh    17  ami  _'  t.   I'.MI:>. 


i':.,-     •        ports     the    following    results:      (1)    At     the    moment    of 

.       die  elect  mile  connected   with   the  capillary  elec- 

[,  ;•     the  internal  surface  of  the  fresh  frog-skin  is  always  positive 

,-,.   ;ind   the  direction   of  the  current    is  as  shown    in 

;•»,,.       •_'      |'he     :.:-::':"'i   of  the  positive  condition  varies  with  dif- 

;       •  •  1    ,-oluti  'i,s.      It    i.-    soon  reduced  to  zero,  changes    to  a  neg- 

,    becomes    /.en i.      When   the  fluid    is    a   cen- 

oi    Ilxi,.  the  inner  ,-urface  of  t  he  shin  immediately 

[,   -it  i\-e.  and  the  change  to  a  negative  com  lit  ion  occur.-  wit  h  in 

ten  minutes,  if  at  all.      \N  it  h  a  cent  i- 

:,tir  normal  solution  of  HX<  >.,  the  change 

1  i  • 

,  trom   a   ])ositi\'e   to  a  negative  conui- 

t  ion  occurs  in  alu  >ut  a  minute,  and  t  he 

negative   condition    lasts    for   several 

4-  minutes.       10     A    piece    of    skin    no 

longer     presenting     a     difference     in 
i 

potent  ial   after  a   cert  am  duration   of 
contact    with    rather   a    strong   solu- 


difference  of  potential,  sm-h  as  would 
have    Keen    obtaim-d    at     iir>t   \vith   a 

••  -  i!  i'inji.  1'  The  frog's  skin  ciintiiiiH-s  to  ^i\-e  electric  reac- 
•  i  ••  -  •  'id  soj  itiiiiis  as  l-i!Lr  as  two  or  three  days  after  the  fro-: 
:.  •-  ii.-i-i  1  1  '."7.  ex]ilait:s  thoe  facts  by  the  theory  that  strong 

ac;ii~  •:••    tnoj-e    po^.s-crful   stimulants  to   tin-  .-km  than   weak  ones,   and 

•   ••    •     lirecti  .ii   of   the  ciii'i-ent    of  rest    more  quickly. 
i  'Inn     _        ••  •     ,     ,•   •    ese  facts  and  of  the  results  reported  by 

I.I)'  hoi  IT  for  a  lon<r  t  irne  in  disi  illed  water) 

."'     -'.."    electric    n-acn'oliS.       These    are    a    pl'ojierty    of    fresh    skill 

'.  :'  :  i     [H'opel'l  i.  -. 

II.    '  .         •  '  recent  ly    found  t  hat    t  lie  inner  surface  oj    t  he    -kin 

t'  ad  of  po.-it  ive  with  a  solution  of  1\  \i  »  .  and  t  hat 
•  re  obtained  wit  h   -ojut  ions  of   l\  I.    K<  '!.  or   Klir. 

' 


IN. 


\      - 


\.    I).    \\':,ii'T     ^Proceedings    of    the 

•  Ilidl  |(.ti  rj.  .  :.•••.  e  nidi'  Ithee],  ,-]  ric  react  ii,ns 
Lr.  c;«i .  and  ma!i.  'I  ey  ha  \-e  -hi  ,•/.  n  i  ha.i  •  iiivct 
•  lead.-  to  a  perl  irbat  ion  of  t  he  current  i  ,f  rest 

'  >\    [n-esent  :•  LI   a   M'^M  ive   varial  ion, 

o| 

•     .•    •  •  t  t.c-e  cii  :"•'   !,'  '  hen,,         in, i 

:  '       '   '  :  •          '  en.brane  dit'f  cable 


Tlie   Current    of    Hc-t.      \\  •  •  • 


ELECTRICITY    orcURHING    IN     ANIMALS    AND    PLANTS 


271 


plate  in  a  voltaic  cell,  and  if  a  wire  is  connected  with  the  two  portions  of 
the  body,  an  electric  current  will  flow  through  the  wire  toward  the 
portion  which  is  "  negative  to  t  he  other."  The  portion  which  is  negative 
to  the  other  is  a  region  of  lower  potential.  It  is  not  necessarily  charged 
with  negative  electricity. 

In  the  tissues  themselves  the  current  is  continued  from  the  region  of 
decomposition  to  the  region  of  synthetic  activity.  D'Arsonval's  explana- 
tion is  that  the  difference  in  potent  ial  is  dependent  upon  react  ion  between 
oxidizable  substances  in  the  tissues  and  the  oxygen  in  the  blood  plasma. 
Currents  of  rest  are  electric  currents  the  result  of  the  above-described 
chemic  processes,  and  are  continuous  and  uniform  for  long  periods  of 
time.  They  present  in  this  respect  a  striking  contrast  to  the  currents 
of  action  which  develop  suddenly  in  consequence  of  some  irritation, 
and  as  rapidly  cease  to  flow.  Currents  of  rest  in  mucous  membranes 
flow  from  the  excretory  surface  of  the  glandular  epithelia  to  the  sur- 
face where  the  epithelial  cells  are  in  relation  with  the  blood-vessels. 
If  it  were  practicable  to  connect  an  external  circuit  with  these  two 
layers,  the  current  woidd  flow  through  the  wire  from  the  vascular  to 
the  secretory  surface.  The  latter  corresponds  exactly  to  the  zinc  pole 
of  a  volt  aic  cell.  The  current  between  the  layers  of  a  mucous  membrane 
is  transmitted  mostly  by  the  epithelial  cells,  and  may  be  called  an  entrant 
glandular  current.  In  the  skin  the  current  of  rest  is  generally  from  the 
internal  vascular  to  the  external 
exfoliating  layer.  It  is,  therefore, 
an  emergent  current. 

There  is  no  current  of  rest  in 
uninjured  nervous  or  muscular 
tissue;  but  whenever  such  tissue 
is  injured,  the  damaged  portion 
becomes  negative  to  any  unin- 
jured portion.  This  produces  a 
current  of  rest  which  may  con- 
tinue uniform  for  several  hours. 
it  will  continue  as  a  current  between  dyim 
tissue^)  and  uninjured  ones. 

The  current  of  rest  has  long  been 
the  case  of  muscles  and  nerves  in  the  way  shown  in  Fig.  197.  A  nerve 
or  a  cylindric  portion  of  a  muscle  in  its  natural  position  is  divided  by 
two  transverse  incisions  and  an  external  circuit  is  applied  with  a  delicate 
measuring  instrument.  Currents  will  flow  throuirh  an  external  circuit 
from  any  point  distant  from  the  center  of  one  ot  the  transversely  cut 
surfaces  to  any  point  nearer  that  center.  The  diagram  shows  a  number 
of  such  external  circuits  with  the  direction  of  the  current  of  rest  through 
them.  It  will  be  seen  that  the  surface 
across  tin"  muscular  or  nervous  libers  is 
the  muscular  or  nervous  bundle.  It  is  fo 
properly  and  in 
bv  reference1  to 

points  may  be  determined.  The  point 
in  either  direction,  is  negative  to  a  pi 
is  true  whether  the  points  are  on  the 
equator.  Applying  the  test  elect  rod 
transversely  cut  surface,  at  the  end: 


the 

which   the   polariu 
\\  hich  is  furt  her  froi 
lint   nearer  the  equal  >  >r 
same  i >r  on  opp< isite  sii 
•s    to    the    middle    poin 


accordingly  be  found  that  there  is  no  difference  in  potential  and  hence 
:.     <•  irn  •  t. 

!':.«•  insertion  of  a  tendon  into  the  periosteum  of  a  bone  corresponds 
to  a  Ira!  >\vrselv  cut  surface,  and  accordingly  a  current  ot  rest  is  found 
to  exi.-i  if  impolari/.able  electrodes  are  applied  near  this  attachment 
;md  t"  t  in  •  -mi'iace  oi  t  he  muscle  or  tendon. 

Kxperiments   have   been    made   by    Bernstein   and   Tschermak  upon 

,;    ivst    in    muscli's   i"   determine   whether   there   is   a   pre- 

rxisteiit    dilTerence   in    potential    between    the   transversely   cut   surface 

of   a    i  •  its   longitudinal   surface,    or   whether   the   difference 

later  in  consequence  of  chemic  or  other  alteration.     Bernstein 

-   thai    t'he  current    of  rest   shows  its  maximum  strength  innne- 

dia'ely.      S.    (Jarlen1    thinks   he   has  shown    that    llMlly    or   -, -,?,->,-,-   second 

rlap-e   befoiv   the  current    develo])s.      And   when   the   muscle   is  cooled, 

M!  of   .   :'0-    second  may  elapse. 

A  carefully  prepared  muscle  upon  whose  longitudinal  surface  are 
placed  two  non-polari/able  electrodes  wet  with  Ringer's  solution  does 
not  \i\  •:  rest  (Biedermann).  But  R.  Hober  finds  that  a 

•     if  rest    develops  when   the  extremity  of  the  muscle  is  dipped 
into   a   solution   of  potassium  chlorid.      Other  solutions  which  produce 
•    is  •  I'ft-ct  :  re  oi  salts  of  lit  hium,  sodium,   cesium,  ammonium,  rubidium. 
nth  the  an  ions  C,  X.  S.  \(  ).,.  I,  P>r,  Cl,  acetic  acid  radicle. 
S<  >.,  tartaric  ainl  citric  acid  radicles.     In  each  list  the  last  is  most  favor- 
able '  <  velopment  of  a  current  in  the  normal  direction;  that   is. 
c    .":•    •              :  to  a  negative  condition  of  the  extremity  of  the  muscle. 
I..  Hermann's  experiment  was  performed  by  means  of  a  fall-rlieotome 
.1  -    :  -  ct  1011  '  i  i  rough  t  he  muscle  simultaneously  wit  h  its  mak- 
::._r  'he  contact   of  an  electric  signal.      The  tune  that  may  elapse  before 
>p!!i'-ni  of . -i  current  of  rest  may  be  the  time  it  takes  the  injured 
::.;-•,:,::   -ub-taiice  to   die;  or.  according  to  DuBois-Reymond,  it  is  the 
the  sriiiipi  nneable  membrane  takes  to  lose  its  permeability 
••  negative  ions  o|   the  muscular  fiber. 

1 .  1  >•  .  '  -'••.:;  and    \.    I  -ci.cri :ia k"  have  pt •rtormed  t  he  same  experiment 

.'    !'  r   :     •:'<•  exact    c  >ndi' ii ins  with  an  electric   motor  and   photographic 

'.    '        '  -hown    the   presence  nf  a   current    of  rest    in  an 

econd.     '1  his    re-ult    is    more  in  accord    with    the 

'  ••'  ce  oj  t  his  muscular  cur n -nl  i  han  with  any  1  heofy 

1     could   occur  in   such   an    iufinitesiinally 

nerves   has  been  studied  liy   K.  Hellwig.1      He 

teli'-e    ;>    pro\-ed    b\"    the    corres[  loiidence    between 

in-rvi    .  -    filament ,      I :    is  an   asccin  1  mi:  current 

:'oLr.  and  a  descending  current   in  i  he  elect  ric 

i"      !•••!'  '•'  ''••   ••'•!.      This   has   ;il]    been    established   by 

I  '  -1  '    :      '  'i     M.  nd<-lssolm.      Schultx  has  studied  the  relation 

'    '  liol    icin  H    :    ;',]-><  :  he   influence  of  the   leliirt  h 

''•'-"•     "'    ' ;  ••   n.xia]    current .  and    t  he   negal  ive 

•:    - '  :  it.       l'he  h    port    •  •    fact    is  that 

'a!  and   flows  from  the  s:antrlion-cell   from 

'    \:  '    ,••      i,    "Ml      1 

•  r  •.         •     '   •     -  • 


ELECTRICITY    OCcrUKl.NC    IX    ANIMALS    AM)    PLANTS  J<.} 

which  a  nerve-fiber  derives  its  trophic  influence.  \Ye  should,  therefore, 
find  that  the  axial  current  in  a  sensorv  nerve  flows  from  the  ganglion 
on  1  he  posterior  root  of  the  spinal  nerve  toward  the  periphery  in  the 
nerve  itself,  while  in  the  posterior  root  the  axial  current  flows  toward 
the  spinal  column. 

The  Galvanic  Muscular  Wave  or  Porret-Phenomenon.  A 
mu-cle  undergoes  changes  in  contract ibility  when  dipped  into  various 
liquids,  such  as  distilled  water,  solutions  of  the  alkaline  salts,  veratrin. 
This  increase  in  contract  ibility  traverses  the  muscle  in  a  wave-like 
manner.  It  implies  an  increase  in  electric  excitability,  as  well-as  in 
capacity  for  contraction.  Kuhne,  in  ls(i(),  Hermann,  in  is'Js,  and 
{•'..  Meirowsky1  have  studied  this  experimentally. 

77/f  Alkaline  Dcniurcntion  Cnrr<  nt  n/nl  tin  \\  <c/  In  n'fiich  if  /'.-.-  Ati'<ft<d 
hi/  Cullnidx. — H.  Mostinsky-  has  made  quantitative  researches  upon 
thi>  subject.  He  placed  the  gast  rocnemius  muscle  of  a  frog  in  contact 
with  solutions  of  different  strengths  of  chlorid.  nit  rate  or  monophosphate 
of  potassium.  This  was  continued  until  the  electric  potential  of  the 
immersed  part  remained  stationary.  The  difference  in  potential 
between  this  part  and  a  transverse  section  of  the  muscle  was  measured. 
There  is  equality  between  the  two  when  a  l.-'i  per  cent,  solution  of 
chlorid  of  potassium  is  used;  the  electromotive  force  generated  at  the 
line  of  demarcation  between  the  alkaline  solution  and  the  electromotive 
force  called  the  current  of  rest  are  equal.  The  addition  of  any  colloid 
substance,  such  as  albumin,  for  instance,  reduced  the  electromotive 
force  due  To  contact  with  the  alkaline  solution.  The  colloid  substance 
interferes  with  the  migration  of  ions  from  the  liquid  into  the  muscle. 
The  unequal  migration  of  positive  and  negative  ions  through  a  semi- 
permeable  membrane  is  supposed  to  be  the  cause  of  most  physiologic 
electric  currents,  and  ions  which  do  not  diffuse  through  animal  mem- 
branes should  greatly  modify  physiologic  currents. 

Currents  of  Action. —  Klectric  currents  are  produced  during  the 
activity  of  nerve  or  muscle  or  of  glandular  tissue.  Those  in  the  latter 
develop  and  disappear  less  rapidly  and  may  be  given  t  he  special  designa- 
tion of  secretion  currents.  The  epithelium  performing  the  glandular 
function  becomes  "negative"  to  the  vascular  part  ot  the  gland.  '1  he 
part  of  the  muscle  or  nerve  which  is  in  activity  is  "negative"  to  other 
portions  of  the  nerve  or  muscle.  The  wave  ot  contraction  in  muscular 
tissue  or  of  stimulation  in  nervous  tissue  carries  with  it  a  state  of  lo\v 
electric  potential. 

The  current  of  action  is  considered  by  -some  authors  as  identical 
with  nervous  activity,  and  by  others  as  an  epiphenomenon  not  neces- 
sarily accompanying  this  activity.  I'.  Schult/.:i  has  considered  this 
subject  of  the  occurrence  of  an  electric  current  corresponding  to  the 
current  of  action,  but  without  the  presence  of  physiologic  activity. 

The  current  of  action  may  be  passed  through  a  transtormer  or 
induction  coil,  and  undergo  an  increase  in  voltage  so  as  to  produce  the 
physiologic  effect  of  high-tension  currents  upon  other  animals.  Currents 
derived  from  heart  or  muscle  contraction  have  been  transformed  in 
this  way  by  Max  Cremer.4  He  has  obtained  very  effect  ive  results  with 

1  Archiv.  f.  die  t^csum.  Physiologic,  vol.   Ixxiii,  p.  -H'J,  1V'.». 

2  Ibid.,  vol.  civ.  p.  ::•_'().   I'.iiH. 

3(Vntrall)latt  f.  Physiologic,  vol.  xviii.  p.  I>1!>,  IVrcmbcr  Ml .  I'.'Ol. 
4  Zeitsch.  f.  experiment.  Pathol.  u.  Tln-i-apic.  vol.  xlvii.  p.  i:>7.   l'.H).V 
IS 


274 


MI.DICAI.   I.I.KI  TKieiTY   AND  KONT<;KN  RAYS 


a   frog's    heart.     Ma  rev.  in    1S77.   used   a   transformer  in  studying  the 
electric  r-hock  from  the  torpedo  <\r  electric  eel. 

The  Voltage  and  Amperage  of  Bioelectric  Currents.  -The  differ- 
ence in  potential  bet\\eeii  all  active  and  a  passive  portion  ol  the  human 
boil\  j>  fnuiul  by  mea.-iirement  with  the  potentiometer  to  be  from 
'•."_'  :<>  n. us  voh  This  i>  a  very  appreciable  voltage,  but,  owing  to 
•lie  ven  irreat  resistance  of  the  bodily  tissues,  the  current  which  it 

mperage.     (Minis'  law  is  o])erative  here,  and 

•  ;he  iv.MMance  is  hundreds  or  t  housands  of  ohms,  the  current  strength 
n  •  -  to  between  I  ,  ainj>ere  or  ^  and     ^  niilliani])ere 

ii     litn  rent  i'a-es. 

In    iiiea.-urini:   currents  of  siicli   small    magnitude  the  greatest    pre- 

.      'ii>  •.    i-i    in    taken   not    to  \-niate  the  results  by  the  production  of 

•  : .  •   :'"!•'•>'  in  a  pj  living  t  he  measuring  apparatus.      Two  ordinary 

;  iieil  to  i  he  e\])osed  muscle  or  nerve,  themselves: 

•  •:  '  •  1 1    '  r  '1    ' '  •-,  ion  n  a  complete  v<  >lt  aic  ci  mple  whose  electromotive 

:     _"/   !>••  i-veii   sirealer  than  the  physi<»logic  one.  and  which  might 

'   the  prmliK'tioii  nf  an  electromotive  force  in  the  tissues 

/  •:•'.••:•  wnh   or   in   oppn.-nion   to  the  natural   one.      In   any  case 

liflicult    to    say  to  what  extent    the  values  found  \vere  due 

'"  '     '  :  to  artificial  causes  connected  with  the  measuring  instru- 


j.  I'.i'J.  —I)  Arsonval  s    cle-ctrudo:    n. 


•    wliifli  i-  fused   fhlnrid   nf  silver- 


Impolarizable    Electrodes.      Klecmides  which   are  as  free  as   pos- 

-•'••'•   •:.-".:  :>;!;Lr   effect    al'e  t  hose  suggest  ed  by  Heynault 

'-•  l'.'s  .        I'oth  electrodes  are  jusl'  alike,  and 

\vhich  i  lie  conduct  in<r  wire 

•    :       ''  ;;  concent  rated  solution 

'   i   •  -  Hosed   MI    the  bottom   by  chiy 

'   I.    _  Thi     da\    is  ^haped    like  a   pencil, 

:'if>ola!'ixable     elect  roije    is    not     completely    SO,   bill    IS 
he  les-  di  licate  experiments.        It. 

;         '     '  '          fi?M    op,  i,  point  and  filled 
h1:::..   i    :    IIIIMI.  ii  .    ei-sed  a 


of  silver. 

eiecli-odr-  ,    IM;    ,  „  .,. 

;riied    o}j     aiiiouiit  ing   to 

ce   TII  1  1,1  current. 

'  •  e-  in  tin  i     ijver. 


ELECTRICITY     OCCl'RRINC     IX     ANIMALS    AND     PLANTS  275 

A  similar  typo  of  impolarizable  electrode  consists  of  a  jar  containing 
a  saturated  solution  of  sulphate  of  zinc  into  which  a  zinc  wire  leads, 
and  from  which  a  piece  of  filter-paper  saturated  with  a  ,,/,,„  solution 
of  chlorid  of  sodium  leads  to  the  tissue  to  be  tested.  The  electrode 
from  the  other  terminal  of  the  galvanometer  is  of  exactly  similar  con- 
struction. This  type  of  non-polarizable  electrode  is  not  available 
when  it  is  desired  to  apply  the  elect  rometric  measurement  to  a  verv 
small  surface. 

Electrodes  of  mercury  and- a  solution  of  chlorid  of  potassium  are 
only  feebly  polarizable,  and  so  are  electrodes  of  cadmium  in  a  deci- 
normal  solution  of  chlorid  of  sodium.  Electrodes  made  of  gold  and 
cadmium  coupled  together,  or  of  gold  and  silver,  or  of  gold  and  copper, 
or  of  aluminum,  or  of  aluminum  and  cadmium,  are  feebly  polarizable. 
The  oxidizable  electrodes  of  silver,  nickel,  copper,  tin,  or  mercury  are 
not  free  from  polarization.  \Y.  Cowl1  has  made  a  thorough  study  of 
this  subject,  with  the  result  in  favor  of  PuBois-Reymond's  electrodes 
of  amalgamated  zinc  in  a  neutral  saturated  solution  of  sulphate  of  zinc. 

Muscles  and  nerves  are  themselves  polarized  to  a  slight  extent,  oven 
by  very  weak  currents,  without  regard  to  the  nature  of  the  electrode. 
Currents  as  weak  as  0.0044  milliampere  will  produce  this  effect.  The 
most  dedicate  galvanometers  are  required  for  the  measurement  of  these 
currents.  The  Thomson  astatic  needle  or  the  d'Arsonval  movable  coil 
galvanometer,  if  made  with  a  great  many  turns  of  fine  wire,  is  suitable 
for  measuring  the  current.  The  capillary  electrometer  is  the  best 
instrument  for  use  in  the  potentiometer  in  measuring  the  voltage. 

The  mercury  and  calomel  normal  electrode  can  be  used  in  the  way 
explained  on  p.  177  as  an  absolute  measure  of  the  potential  of  a  single 
electrode  applied  to  any  part  of  the  bodily  tissues.  The  difference  in 
potential  between  any  two  portions  can  be  readily  calculated  from 
their  absolute  potentials. 

The  current  of  action  is  always  present  when  a  muscle  contracts  or 
a  nerve  transmits  an  impulse.  This  occurs  whether  the  function  is  per- 
formed in  consequence  of  natural  or  artificial  causes.  And  there  is  no 
current  of  action  without  the  performance  of  function;  and  no  perform- 
ance of  function  without  a  corresponding  current  ;>f  action.  1  he 
current  of  action  is  found  in  the  muscle  when  the  latter  contracts  in 
pinching  or  pricking  its  motor  nerve1. 

Wave  of  Negative  Variation.  The  current  of  action  or,  to  be  more 
exact,  the  wave  of  low  potential  travels  faster  in  the  higher  animal  or 
or^an  than  in  those  of  lower  development.  It>  duration  is  short  if  its 
propagation  is  rapid.  The  rate  of  the  latter  is  sometimes  !!()  meters 
a  second.  A  galvanometer  may  be  connected  by  DuBois-Roymond 
elect  rodes  wit  h  two  port  ions  of  t  he  length  of  a  nerve  which  is  uninjured, 
and  conseqiientlv  presents  no  current  of  rest.  Then  it  an  irritation  is 
applied  to  some  other  part  of  the  lenu'th  of  the  nerve,  the  galvanometer 
will  probably  fail  to  show  any  current.  This  is  due  to  the  fact  that 
when  the  wave  of  low  potential  reaches  tl  e  point  nearest  the  place  of 
irritation,  the  point  reached  becomes  negative  to  the  other  more  distant 
point.  At  a  later  period  the  wave  of  |o-  •  potential  reaches  the  more 
distant  point,  and  conditions  are  reversed.  A  current  will  accordingly 
pas>  through  the  galvanometer  at  first  in  one  direction  and  then  m  the 
other,  and  the  alternation  is  aecomplisl  i  :  in  such  a  short  space  of  time 
i  Archiv.  t'.  I'hvsioluirif.  1  v.i.  :;-.v>. 


Ml. I'll    \1      1.1. 1. 1    IKI<    1  I  "l      AM)     U< 'N  1  lil-.N     K\YS 


that   tin1  ordinar\   galvanometer  will  indicate  neit  her  current .      A  photo- 

ic  chart  of  the  capillary  electrometer  will  .-how  these  two  currents. 

succeeding  each  other  and  in  opposite  directions,  and  so  will  Hint  ho  veil  s 

iraivaiionieter.  which    react.-  with    extreme   rapidity.      During  a 

tetaiii  ctimi  ol  a  muscle  caused  by  a   rapid  succession  ol  stimuli, 

such  as  the  faradic  current  (applied  at   a  point   not   included  bet  ween  the 

i  v,  o  electrodes  from  the  galvanometer),  the  circuit  formed  by  the  galvan- 

••    •  •-  '      nd  the  incl  idi-d  portion  of  muscle  will    be  the  seat   of  a  mono- 

phase  al  i  ern  at  ing  current .     I  nder  these  <Jrcu  instances  the  galvanometer 

-  •  ••,.•••  11  -  -iiows  a  deflection  indicating  that   the  wave  ol  low  potential 

!--•••••  [hi    point   nearest   the  source  of  irritation,  and  loses  some 

o;    it-   strength   before   reaching  the   more  distant    point.      'Ihe  current 

i.    -troimer  in  one  direction   at    the   first    period   than   it    is  in  the 

[  ion  at    the  second  period.       The  name  <l<  <T<  minimi  current 

:.    -  been  Lriven  to  this  preponderance  of  current   in  one  direction  which 

;-  -  iinet  imes  denn  >nsi  rable. 

There    is    a    chronologic    correspondence    between    the    myographic 
curve   indicating;  shortening  or  lateral  swelling  of  a   muscle  stimulated 
:Md  t  he  elect  ro metric  cur\'e  indicating  the  wave  oi  negat  ive 
••  .        V  'i  t  his  is  true  of  hot  h  iso tonic  and  isomet  ric  contraction. 
Ihe    most    satislactory   observations   upon   the   rate  of  transmission 
of  •  :..•  "negative"  wave  or  wave  of  lo\\   potential  have  been  made  upon 
living  muscle  and  nerve  preparations  with  parallel  transverse  sections. 
Ihese  tis.-ues  have  a  current  of  rest  which  is  fairly  uniform  and  is  caused 
h\     ihe    low    potential    at    the   transversely   cut    ends   of   the    muscular 
Under  or  of  the  nerve.     A  potentiometer  with  one  DuBois-Reymond 
electrode  applied  at   a  point   on  the  longitudinal  surface  of  the  muscle 
and  another  at  the  transversely  cut  surface  will  show  a  constant  differ- 
ence in  potent  ial,  which,  however, 
is   much  reduced  when  t  he  wave; 
ol     low     potential      reaches     the 
longitudinal    point.      The  poten- 
3       t  ial    at    the  latter  point    will  not 
*        fall    below    that     of     the     trans- 
versely cut  end.  but  it  is  reduced 
t"  an  extent   and  in  a  way  which 
can   be  accurately   determined. 

Appl;-     inipolari/.able    electrodes    at    X    near    cut    surface    and    L    on 
''•    ';    'he   nerve  shown    in   F in.  200.     Then  a  current  flows 
•  i-.'i  '    •     '    Ivaiiometer  trom  I.  to  X  which  is  negative. 

';'ii:  current   at    "    >>.      All  part*  of  the  n<Tve  are 
ijured    and  the  point   /.    becomes   negative   in   comparison 
was    before.      There    is    less    difference    between    /,   and    X 
'    of    rest    is   diminished.      The    wave   of   low    potential 
•'  "I  ici  •   M    vi TV  -harp  fall   in   potential,   followed  by  a  more 
1  '  he  original  level.      \\  starts  from  the  place  of  irritation 
'    ''    'he   latter   is   applied,   without    any    latent    period, 
points   in    period-   of   time   proportional    to   their 
•    ini   ot   irritation.      It   travels  in   muscle  at   the  same 
'     '!  '•"!  traction,  but   very  -li^ht|\-  in  advance.      It  does 
-    maximum    elect  ncallv    before    the    muscular 


ELECTRICITY    OCCURRING     IN     ANIMALS     AND     PLANTS 


277 


The  rapidity  of  the  forward  progress  and  of  the  fall  and  rise  of  the 
wave  of  low  potential  varies  in  different  tissues.  Boruttau  gives  the 
following  as  the  order  in  which  they  increase  in  rapidity;  medullated 
nerve-fibers,  striped  muscle,  non-medullated  nerve,  cardiac  muscle, 
unstriped  muscle.  The  fastest  rate  is  about  .'iO  meters  a  second. 

The  duration  of  the  negative  wave  at   any  point  varies  inversely 
with  the  rapidity  of  progress  of  the  wave,  and  with  the  abruptness  of 
its   rise   and   fall.      Examples 
given  by  Boruttau  of  duration        + 
of  the  low  potential  are:     (1) 
In  the  striped  muscular  fiber 
of    the    sartorius    in    a   frog, 
0.06  second  or  more,   and  of 
this,  0.005  second  elapses  be- 
tween the  commencement  and 
the    maximum    of   the   wave; 
the  subsidence  takes  ten  times 
as  long.     (2)  In  the  sciatic   nerve  of  a  frog  the  wave  takes  0.006  or 
more  second  to  pass   a  given  point  and  0.001  to  reach  its  maximum. 

The  words  irritation,  stimulation,  and  stimulus  are  used  synony- 
mously in  these  paragraphs. 

An  alternating  current  passes  through  an  external  conductor  whose 
two  electrodes  arc  applied  at  points  along  the  course  of  a  nerve  or 
muscle  at  different  distances  from  the  point  of  irritation.  In  the  case 
of  a  single  application  of  the  irritation  the  electric  potential  at  the  nearer 
point  as  compared  with  that  at  the  farther  point  will  show  changes 
corresponding  with  the  wave  of  low  potential,  providing  that  the  two 


Fig.  201.—  'I 


wave  of   negative   variation   or 
low  potential. 


Fig.  202.— Alternating   relative    potential    produced    as    the  wave  of    negative   variation 

advances. 

points  are  far  enough  apart  for  the  wave  to  completely  pass  the  first 
before  any  part  of  it  reaches  the  second  point  and  providing  the  wave 
loses  but  little  force  (in  the  shape  of  decremential  current).  The  graphic 
chart  of  the  potentiometer  would  give  the  potential  at  the  first  point, 
relative  to  that  at  the  farther  point,  shown  in  Fig.  202.  Before  the 
arrival  of  the  wave  of  low  potent  ial  the  relat  ive  potential  is  zero:  with  the 
arrival  of  the  wave  it  falls  by  a  sharp  incline  a  few  hundredth*  of  a  volt 
and  then  by  a  much  longer  incline  rises  to  the  zero  level  where  it  remains 
until  it  shows  an  abrupt  rise  of  a  few  hundredths  of  a  volt  and  a  gradual 
fall  to  the  zero  level.  This  curve  of  relative  high  tension  at  the  nearer 
point  indicates  the  presence  of  the  wave  of  low  potential  at  the  lurther 


_>7^  MKDH'AL    KI.Ki'TKK   II  V     AM)    KO.Vn.KN     HAYS 

p,,iiit.  The  i.nly  change  occurring  in  the  absolute  potential  of  the 
nearer  point  is  at  tin-  time  that  it  shows  a  wave-like  fall,  followed  by  a 
;••;„,.  •,,  the  /.i  IM  level.  From  this  time  on  the  absolute  potential  at  the 
lirst  point  i-  unchanged.  but  it  shows  a  wave  of  nlutirrl  ;/  high  potential, 
indicat  i\  e  if  •  he  arrival  of  the  area  of  low  potential  at  the  further  point. 
y;,  /•;,,•  c  Variation*  in  tin  H  u  man  Heart.  These  may  be  registered 
b\-  a  capillarv  electrometer  connected  with  non-polari/able  electrodes 
phu-ed  •.';,.,;;  the  surface  of  the  body  near  the  ba>e  and  near  the  apex 

of    the    heart. 

1,  ,//,,,•  /•,'./•/;  //,///  *    -,/    \ii/iitirt'  Variation  in  n  Xcrn.  —  Impolarizable 

,,  -  ;lre  applied  I"  the  lateral  surface  and  the  cut  end  of  a  nerve. 

The  hitter,  bi-inii  iii  jured  tissue,  is  negative  to  the  former,  and  a  current 

:!  ,..vs  •''..'.•«•  ;^''.  i  the  iralvanoineler  from  the  lateral  surface  To  the  cut  end. 

\      ,;     [j,.  ,.  irrent    may  now  be  applied  to  the  nerve  by  two  electrodes, 

xe  together  at   points  at  some  distance,  and  t>oth  in  the  same 

direction,   from   the   part    to  be  tested.     This  stimulation  causes  each 

ivi    part  of  the  nerve  to  behave  as  if  injured.     The  galvanometer 

sho\\s  a   weaker  current   from  the  lateral  surface  to  the  cut   extremity 

,(f   •;.,     nerve,   and   this   indicates  that    the  lateral  surface  has  changed 

ttiv,  -.:   :   a   rieiral  ive  electric  potent  ial. 

h  is  very  easv  to  ol»serve  the  negative  variation  causeil  by  a  con- 
•::.•;.;-  current  flowing  for  a  considerable  length  of  time,  and  it  is  also 
possible  b\  lelicaie  apparatus  to  show  the  negative  variation  due  to  a 
current  lasting  in>  longer  than  an  electric  spark.  Such  observations 
as  the  latter  >ho\v  that  the  negative  variation  occurs  a  certain  length 
o!  time  ifti-r  the  application  of  the  stimulus,  and  that  the  retardation 
>  ii  proportion  to  the  length  of  nerve  to  be  traversed.  The  negative 
\  .•  ,.-ion  or  cotidition  of  negative  electric  charge  advances  in  a  wave- 
ihe  point  of  ap])licatii»n.  The  rate  of  propagation 
o!  •  iie  v.  a  vi'  oi  neirat  ive  vai'iat  ion  is  found  to  be  the  same  as  that  of  the 


\'nr<  nf  I.  mi-  I',  iti  ,  it  iii!  In  Si/j><  rjt'is/t  inn  (Hermann),  — 

when  only  the  absolute  potential  at   a  single  point 

t  he  wave  is  seen  to  pass  as  a  single  sharp  depression 

more   '_rradual    return    to    it.      There   is 

e   o]ij>o>jte.    positivi     direction.      The   original    level 

tei  tial    which    luav    be    xero,    or   somewhat    above   or 

c    wave   of   ]o\\-    potential    masked    by 

'he     relative    jiotential     i-    (il)served    bet  \\een     two 

betv.-een    which     -   greater  than    (lie  total   length  of 

'  •  •    ab-iilu'e  p   tent  ial  at  the  nearer  ]n  >int  ret  urns 

rial  potent  ial  1  »••'<  i  re  t  he  \\  a  ve  -  if  low  potent  ial 

','  •  •  '  .       I)';1'];:'/  i  In    en  1  ire  pa--a'_re  of  t  he  wave  of  low 

•  •   ;  i  chaiiire  from  t  he  original  level  a1 

•  •  ••'••,  •:••/'     :•     I'elai  ive  potent  ial   is  due  simply  to 

'    t  he   ',;  •-•    point  .      Similar!  Y.   t  he   passage  of 

•.'  '    i     '!       ••'        factor    in    determining   the 

[lotential    at    the   first 

1   '  '  •      ''   ••'•:!    !>  '\'e]  oi   equal    potent  ial  . 

1      ii      I  'ig.     _'!!_'.  where  the 

•'••'!  '  '.  not   bei-ause  t  he  absolute  iiotent  ial 


ELECTRICITY    O('(  UKKINCi    IN    ANIMALS    AND    PLANTS 


270 


is  necessarily  zero,  but  because  the  chart  is  0110  of  the  relative  potential 
of  the  nearer  point  as  compared  with  the  potential  at  the  further  point. 
The  level  marked  ()  is  the  level  at  which  there  is  no  difference  in  poten- 
tial between  the  two  points. 

The  case  in  which  superposition  masks  the  wave  of  low  potential  is 
that  in  which  the  electrodes  of  the  potentiometer  are  applied  at  poiins 
.so  near  together  that  the  beginning  of  the  wave  of  low  potential  reaches 
the  further  point  before  the  \vave  has  completely  passed  the  nearer 
point.  The  relative  potential  at  the  first  point  is  determined  partly 
by  the  change  in  absolute  potential  occurring  there  as  the  wave  of  low 
potential  passes,  and  also  by  the  change  in  absolute;  potential  at  the 
further  point.  Fig.  203  shows  the  curve  of  relative  potential,  the 
heavy  line  being  the  actual  curve.  The  dotted  line  shows  the  curve 
which  would  be  formed  under  the  influence  of  the  wave  of  low  potential 
at  the  first  point  alone.  The  interrupted  line  shows  the  curve  of  relative 
potential  which  would  occur  under  the  influence  of  the  wave  of  low 
potential  at  the  further  point  alone.  At  the  beginning  the  wave  of  low 
potential  is  not  masked,  and  the  curve  is  due  simply  to  the  wave  of  low 
potential  at  the  nearer  point.  Hut  at  a  later  period  of  time,  represented 
by  progress  toward  the  right  in  the  diagram,  the  curve  is  modified  by 


Fig.  293.— Masking   of  the   wave  of 
negative  variation  by  superposition. 


the  fact  that  the  wave  of  low  potential  has  readied  the  full  her  point. 
At  any  given  time  after  this  the  actual  relative  potential  at  the  nearer 
point  is  intermediate  between  the  relatively  low  potential  due  to  the 
wave  of  low  potential  at  this  point  and  the  relatively  high  potential  at 
this  point  duo  to  the  wave  of  low  potential  at  the  further  point.  The 
result,  as  shown  in  the  diagram,  is  thai  a  potentiometer  whose  specially 
prepared  electrodes  are  at  two  points  of  the  longitudinal  surface  of  the 
nerve  will  show  the  wave  of  low  potential  as  a  sharp  fall  in  relative 
potential  at  the  nearer  point,  with  an  equally  sharp  recovery,  but  with 
only  a  slight  deviation  in  the  opposite  direction,  <>t  relatively  high 
potent  ial.  The  second  phase  is  st  ill  furt  her  reduced  if  t  here  is  a  material 
loss  in  power,  as  the  wave  of  low  potential  progresses  along  the  nerve 
(decremential  current).  Accordingly,  an  exceedingly  sensitive  galva- 
nometer.— 1000  to  21. (KM)  turns  of  very  fine  wire,  connected  with  two 
points  of  the  length  of  a  nerve  nearer  together  than  the  length  oi  tin* 
wave  of  low  potential,  would  show  the  presence  <>t  a  decided  current 
in  a  direct  ion  from  the  further  to  the  nearer  point  in  the  external  circuit. 
followed  by  a  much  weaker  current  in  the  opposite  direction.  1  In- 
direction nf  the  stronger  current  in  the  nerve1  is  away  from  the  source 
of  irritation  and  of  the  weaker  current  toward  the  point  of  irritation. 
Fig.  204  shows  the  direction  of  the  current  during  the  first  phase  »f  the 


wave  of  !"'•'•   potential  when  the  potential  at  the  point  nearer  the  sourcy 

t.t   irritation   has  a  lower  potential  than  the  furt  her  point .      During  the 

weaker    second    phase,    described    in    the    paragraphs   immediately   pre- 

•  i;    the         and         >ign  and  the  arrows  indicating  the  direction  of 

current    would    In-    re\'ersed. 

Superposition  of  the  negative  wave  or  of  the  wa\'e  of  low  potential 

u  iuld  produce  a  practically  undirectional  interrupted  ctirrent  through 

a   nerve  or   muscle   if  a   series  of  stimuli,   such   as  the  faradic    current, 

applied,    at    intervals   so   short    that    the   successive    waves  ot    low 

[MO    n'  ial  t  r»d  upon  i  -aeli  '  -t  her  s  heels. 

T   •.-...   narcosis,  and  degeneration  make  the  recovery  in  potential 

;,•--   al»i  ipt  l»y  retarding  the  return  of  the  tissues  to  a    normal 

:    •       fter  t!ie  passage  of  the  influence  which  has  caused    the  tall 

in    potential.      The   curve   representing   the   passage   of   a   wave   ot    low 

p   •    ••;,!  consequent  upon  a  single  irritation  would,  accordingly,  show 

ipt  fall.  Inn  a  much  more  gradual  rise  to  the  original  level. 

\\  ;ii  •  '  lences  referred  to  were  very  marked,  the  fall  in  potential 

•  lie  retarded. 

/.•''.-'  «;  \iirrnticx  n/nm   \fi/utt'i~<    \'<i  rmtion   m  tin    A  trrt1. — A  nerve 

i-  exposed  to  the  vapor  of  et  her  or  of  chloroform  does  not  exhibit 

a  m  _'   r  i\-i    va riat  ion  when  st  imulated.  but  it  will  do  so  after  the  narcotic 

i-  •'.  /  .  •  I —  it  has  been  applied  too  strongly  or  for  too  long  a  time. 

I'arboi  :<•  acid  increases  the  negative  variation  m  small  doses,  but  it 

ac'-  like  chloroform  or  ether  when  applied  in  huge  doses. 

.!'/  i  jin    «J  fcmrt  nf  l-'ntiifui-  ii  [in-tt    \<  f/'ifirt    ]~n  riiit/ir,,   rn  On    \<rr/. — 

.     tiou    >f  the  nerve  at  regular  intervals— every  minute,  for  example 

re-  ih-  ::.   an  equal  negative  variation,  as  shown  bv  the  electrometer. 

•-.•     the    :•'  -ul'  i'.ir    muscular    contraction    becomes    progressively    less. 

,         net;    live    variation    in    the    nerve    is    closely    associated    with    the 

tran-mis-ion    of    the    nervous    impulse.      The    fact     thai    no  diminution 

••    in  t  he  negative  variation  of  the  nerve  leads  to  the  conclusion 

'    "pa    :.<  :".'••  does  not    undergo  a  change  m  t  ransmissibilit  y  in  conse- 

•  •  it  imje.      'I  he  lessened  muscular  font  ract  ion  i-  due,  therefore. 

'     '  it!  ••        '    '  '  •      muscle    Mself. 

v'l  r\    portion  of  the  wave  and   draws  out  the  graphic 
1  'al    direction,    while    warmth  ha->  a  contrary    effect. 
I'.o;  ittau,    both     thi-s<-  influence  only  the   portion   of   the 
'   •    .vhich    they    are  applied,  not    the    other  portions  of 

;  r;  i  '. '  -  and  other-  to  be  described  arise  in  the  various 
'       perton    ance  ol    t  he  vi  ilunta  ry   atn  !    in\  olunt  ary 
•  •  •  '    ble  life.      hi-  only  in  cert  ain  except  ional 
'  lie  potent  ial     •_••  •  '       i  .  as  to  pn  uluce 

It    t  hi         il   of  appa  rat  US.       The    \  a  rii  dis  elect  ric 

ii      i-'.-i-v,     pp.i      ice    i-lect  I'ic     i|  isclia  I'ges     \'i'  >len1     enolltrh 

•    .••-.,.,•     |,.fe:    ••.  and  to  [.roduce  a   beuunibinn 
modified    t!  '  .     t  ne 

• 


I-'..,-'      •  :, 


plete 

retr,., 


ELKCTKHITY     <)C(  'I'  HKI.\<;     IN     ANIMALS     AND     PLANTS  281 


i  > 


as  being  set  up  in  multiple  scries.  The  voltage  is  sufficient  to  produ 
an  electric  shock,  and  the  amperage  is  distinctly  appreciable  l>v  th(; 
galvanometer  (electromagnetic  effect)  or  the  voltameter  (electrolytic 
effect). 

Currents  of  action  occur  in  plants,  especially  in  the  sensitive  plant 
and  others  which  respond  visibly  to  irritation.  They  are  similar  to 
those  in  animals,  but  the  wave;  of  lo\v  potential  progresses  more  sloulv. 

The  rate  of  progress  of  the  wave  of  lo\v  potential,  not  over  •')()  meters 
a  second,  and  often  very  much  less  in  the  case  of  the  current  of  action 
in  plants  or  animals,  does  not  indicate  the  rate  of  transmission  of  the 
same;  electric  current  through  the  tissues.  It  simply  corresponds  with 
the  changing  position  of  the  active  electrode  in  the  natural  voltaic 
couple  whose;  electromotive  force  causes  the  current  of  action.  Fig.  205 
may  serve  to  elucidate  the  matter. 

The  velocity  at  which  the  current  flows,  possibly  ISO, 000  miles  a 
second,  will  not  bo  materially  altered  if  the  pair  of  electrodes  are  moved 


Fifi.  205. — A  zinc  and  a  copper  electrode  are  immersed  at  the  points  jc  and  r  in  a 
lout:  trough  of  a  liquid  or  gelatinous  electrolyte  and  are  connected  l>y  an  external  circuit 
which  includes  a  galvanometer,  ('hemic  action  takes  place  by  which  the  /inc  is  attacked 
and  becomes  the  negative  pole  of  the  resulting  volt  aic  cell.  The  zinc  becomes  "  negative '' 
to  the  copper  in  the  sense  that  its  potential  outside  of  the  liquid  is  lower  than  that  of  the 
copper,  and  the  current  in  the  external  circuit  is  ~hown  by  the  galvanometer  to  pass 
from  the  copper  to  the  zinc.  Of  course,  the  current  i.-  continued  through  the  electrolyte 
from  the  zinc  to  the  copper.1 

through  the  electrolyte  at  the  rate  of  a  few  yards  a  second  to  tin- 
posit  ions  ?/'  and  z. 

The  analogy  is  very  close.  As  in  the  case  of  the  zinc  electrode,  the 
processes  taking  place  at  the  area  of  !<>\v  potential  in  the  nerve  or 
muscle  are  the  cause  of  the  electromotive  force.  Under  the  influence 
of  a  power  inherent  in  living  tissue  this  area  of  chemic  or  physical 
change  advances  from  one  part  of  the  nerve  or  muscle  to  another,  and 
so  the  point  of  origin  of  the  electromotive  force,  or  the  negative  wave. 
passes  along  the  tissue.  The  position  <>t  the  copper  is  ot  consequence 
in  determining  the  direction  of  the  current  from  the  zinc  electrode 
through  the  electrolyte,  and  bv  its  distance,  the  amount  of  resistance. 
The  same  remarks  are  true  of  the  ot  her  condition  when  t  he  wave  of  low 
potent  iai  is  at  one  electrode. 

Local  Currents  of  Action. — The  point  at  which  an  irritation  is  ap- 
plied undergoes  a  change"  in  potential  \viiich  is  ot  1  inger  or  shorter  dura- 
tion. It  becomes  "negative"  to  t  he  un irritated  neighboring  portions.  It 
is  dist  inct  from  the  progressive  negative  wave,  and  is  also  not  to  be  ex- 
plained as  merely  an  effect  of  polarization  by  the  applicat  ion  for  an  elec- 
tric current,  such  as  might  occur  at  an  electrode  in  an  inorganic  electro- 


2X2  MKDK   AI.     KLKtTKieiTY     AM)    RONTGKN     KAYS 

lyte.  It  follow-  other  stimuli  besides  electric  ones,  and  is  apparently  a 
vital  phenomenon.  Waller,  in  n>0">.  has  described  bla/.e  currents  or 
alterations  in  potential  at  points  where  the  nerve  or  muscle  has  been 
killed  by  heat. 

ELECTROTONUS 

This  is  the  name  ^iveii  to  the  condition  of  a  nerve  or  muscle  beyond 
and  between  the  two  electrodes  when  a  voltaic  current  is  applied  to  n 
portion  of  its  length.  ( 'uti  In'troto/mx  occurs  in  the  portion  nearest 
the  c:\thode,  and  is  characteri/ed  by  the  flow  of  an  electric  current 
away  from  the  portion  included  between  the  electrodes.  Anelectro- 
t,,:.  is  occurs  in  the  portion  nearest  the  anode,  and  is  characterized  by 
the  {low  of  an  electric  current  toward  the  portion  to  which  the  buttery 


current  is  applied  l>v  the  two  electrodes.  The  portion  "beyond  the 
anode"  has  no  reference  to  the  idea  of  distal  or  proximal  as  regards  the 
natural  relation  of  the  parts  in  the  living  animal.  It  simply  means  the 
|>:iri  of  the  nerve  or  muscle  nearest  the  anode,  but  not  included  between 
the  cathode  and  the  anode.  Reference  to  Fig.  200.  in  which  the 
••  litioii  of  catelectrotontis  is  indicated  at  r  and  of  anelect  rotonus  at  a, 
-.'.ill  siiow  that  the  current  through  the  nerve  in  each  case  is  in  the  same" 
direct  ion  as  the  bat  tery  current  t  h  rough  the  portion  of  the  nerve  between 

Electrotonic    Currents.  These   are  vital   phenomena,  not    merely 
;•  •'.'  upon  the  effect    which  the  battery  current   would  produce  in 


I 


. 


Lianic  conductor  oilt-ide  of    the  part    between  the  two 

'.  '  Xeept    between    the  electrodes    the  currents  are  the 

'i  would  be  produced  l>\  electric  diffusion  (  Fi»;.  207). 

.-   current-   in    the   direction    -down   in   Fit--.  "Jo."), 

1       ppl  •  '•••!'  ]":,    oj    the   battery   current    and    coin  inue 

They  are  different    from   the  current    of 

upplicat  MI     n|     ;i     volt aic   ciiri'ent    wi ndd 

'  -'    :'  '1  '''•••  ';nd  nf  tliat   apj.lication.      Klectro- 

ti"'.u-ly   in   different    part-  of  the  nerve  or 

11    "'•  even   cut  in-l\    ilisappear  at 

between     the     electrodes.       The 

''      ':   '     '"i    pro-rre.-ses  in  a  wave-like  manner. 


ELECTRICITY    <)('(  rUKIN<;    IN     ANIMALS    AND     PLANTS 


283 


so  that  it  occurs  first  in  the  portion  nearest  the  point  of  irritation  and 
later  in  the  portions  further  a\vav.  While  the  current  of  action  mav 
undergo  sonic  loss  of  po\ver  at  a  distance  from  the  stimulation,  it  is 
not  anywhere  near  so  great  a  loss  as  occurs  with  elect  rotonir  currents. 

The  relative  strength  of  aneleetrotonus  and  catelect  rotonus  varies 
in  different  animals,  and  is  influenced  by  various  conditions.  I'mler 
ordinary  circumstances  they  are  about  equal  in  man  and  other  mammals. 

Positive  After-fluctuation. — After  the  disappearance  of  the  local 
current  which  occurs  as  an  area  of  low  potential  at  the  point  of  irritation 
of  a  nerve  or  muscle  a  condition  of  high  potential  is  sometimes  observed 
there  (Hering),  and  to  this  the  name  of  positive  after-fluctuation  has  been 
given.  This  should  be  carefully  distinguished  from  the  second  phase 
of  the  negative  wave  in  the  current  of  action  where  the  potential  is 
only  relatively  high,  and  which  occurs  under  quite  different  conditions. 

These  different  currents  have  been  described  as  a  group  of  currents 
resulting  from  vital  processes.  They  are  not  necessarily  physiologic 
effects  of  electricity,  although  the  application  of  the  latter  is  one  of  the 
most  convenient  means  of  exciting  these  as  well  as  other  vital  phenomena 
experimentally. 

Modifications  in  Electrotonus.— Electrotonic  currents  do  not  pass 
bevond  a  ligature  tied  tightly  around  a  nerve. 


. 
a/  Currenf 


Electrotonic  phenomena  are  much  diminished  by  anesthetics. 

Electrotonic  currents  do  not  immediately  disappear  when  the 
current  is  turned  off.  but  persist  for  a  certain  length  of  time  with. 
oscillation  both  in  the  current  strength  and  iti  nervous  conduct ihil it y. 

Electrotonic  currents  increase  in  intensity  with  the  strength  of  the 
exciting  current,  and  diminish  very  rapidly  with  the  distance  iroiu  the 
portion  between  the  electrodes  (Fig.  'JOS  . 

Physiologic  Effects  of  Electrotonus.  The  excitability  of  the 
nerve  is  increased  in  the  region  of  cat  elect  rot  onus  and  diminished  in 
that  of  anelect  rotonus.  This  is  true  b"th  beyond  and  between  the 
electrodes.  The  diagram  in  Fiir.  20S  shows  the  varied  excitability  of 
tin*  nerve— -greatest  near  the  cathode  ;md  least  near  the  anode. 

Excitability  is  very  decidedly  affected  by  electrotonus.  Fig.  20s. 
r.  indicates  that  at  a  point  midway  between  the  electrodes  the  excita- 
bility is  unchanged.  Proceeding  toward  and  for  a  short  distance  beyond 
the  negative  electrode  we  find  that  the  excitability  progressively 
increases,  and  then  beyond  that  point  ii  ai:ain  diminishes  to  zero. 
Leaving  the  central  oint,  we  find  that  the  excitability  is  gradually 


"JM 


\i.  I:LKCTKICITY  AND 


reduced  until  after  passing  the  positive  electrode,  and  then  gradually 
heci  mies  .:>T"  ai^am. 

Klect  rot  onus  inhibits  nervous  conduct  Utility,  so  that  stimulation  of 
a  :..'••"!•  nerve  at  a  proximal  point  will  not  traverse  the  portion  between 


•:._'  t  In-  -t  imulation  i  >l"  a  motor  nerve  bv  a  faradic  current ;  the  impulse 


:.   tin    •:.  isclr   because  tin1  condui'tion  nf  IUTVC  excitabilit  v  is  blocked  b\ 


•  •••    •        i-i   •,'•-"  i  ;   •    i   by  a   run-taut   current   applied  between  the  faradized  portion  of 


the  electrodes  and  cause  conti'action  of  the  muscle   supplied  by  the 
nerve.     <  >r,  i:'  i;  does  so,  it  will  be  with  reduced  power  (Fi.n.  200). 

l-'iji.  IMO  sh»ws   the   effect    of   anelect  mi  onus   in   reducing   nervous 
excitability.     The  nerve  in  this  case  is  simply  exposed,  not  cut  out  ol' 


ffj'-tffrsr-f   rlTf--0cU 

•xcitabilitv  diminished  bv  aneleetrotonus. 


["•rtioii    in    which    anelectrotonus   is   present    is   that 


vanic  electrodes  and  The  muscle,   and  to  this  part    an 


The  other  faradic  electrode  is 


I1    :  '    "t    'he   animal  -  bod\  .      The  presencr 


' ;  '•   evii  ubilii  v.    and    make- 


>''  rui  •    usual  in  order  to  produce  muscular 


ELECTRICITY    OCCriiKINC     IN    ANIMALS    AND    PLANTS  285 

Nerve  blocking  upon  this  principle  is  made  use  of  in  neuralgia.  The 
anode  is  applied  to  the  nerve  and  the  current  is  ascending  for  sensory  and 
descending  for  motor  nerves. 

The  increase  of  exr.it ability  produced  by  catelectrotonus  is  illus- 
trated by  Fig.  211. 

Electrotonus  Explained  on  the  Theory  that  the  Nerve  Acts  as 
a  Cored  Conductor. —  It'  t\\<>  electrodes  are  applied  to  two  points  on  ;i 
simple  straight  wire,  as  in  Fig.  212,  and  the  current  be  a  continuous 
one.  it  will  traverse  only  the  portion  of  the  wire  between  the  two  elec- 
trodes, and  in  a  direction  from  the  positive  to  the  negative  electrode. 
It  is  different,  however,  if  the  wire  be  immersed  in  a  trough  of  salt 
solution,  which  is  a  much  poorer  conductor  of  electricity  than  the  wire 
(Fig.  21.3).  A  part  of  the  current  will  pass  from  one  electrode  to  the 
other  through  the  liquid  alone.  Another  part  of  the  current  traced 
from  the  positive  electrode  will  be  found  to  go  through  the  liquid  to 
the  nearest  part  of  the  wire,  and  follow  this  good  conducting  path  toward 
the  other  electrode.  Other  portions  of  the  current  radiate  from  the 
positive  electrode.-  through  the  liquid  in  every  direction,  and  reach 
different  points  on  the  wire — some  on  the  portion  beyond  the  positive 
electrode,  others  between  the  two  electrodes,  but  practically  none  beyond 
the  negative  electrode.  As  we  shall  see  later,  tjie  current  or  the  electric 
pressure,  in  the  liquid  is  in  the  opposite  direction  beyond  that  point. 
The  current  Hows  in  the  same  direction  through  every  portion  of  the 
wire.  In  the  portion  beyond  the  positive  electrode  currents  entering 
the  wire  at  any  point  find  the  best  conducting  path  through  the  wire 
toward  the  negative  electrode.  In  the  portion  between  the  two  elec- 
trodes the  best  conducting  path  is  through  the  wire  toward  the  negative 


!•  ijr.  I'll'.  —Conduction  through  a  simple  wire  when  electrodes  are   applied  laterally. 

electrode.  But,  of  course,  at  every  point  some  current  is  escaping  from 
the  wire  to  pass  through  the  liquid  to  the  negative  electrode.  The  same 
escape  of  the  current  from  the  wire  through  the  liquid  to  the  negative 
electrode  takes  place  at  every  point  beyond  the  negative  electrode,  and 
this  enables  tin;  current  to  traverse  the  wire  in  the  original  direction 
right  to  ihe  end.  The  escape  of  current  to  or  from  the  wire  is  greatest  at 
points  close  to  the  electrodes  where  the  force  of  attraction  by  the  oppo- 
site polarity  is  greatest,  and  it  is  least  at  pointvS  far  away  from  either  elec- 
trode, where  the  attraction  is  very  much  weakened  by  the  resistance  of 
the  liquid  through  which  the  current  must  pass.  I  nder  the  conditions 
of  the  experiment  the  only  current  which  can  pass  through  the  wire  is 
that  which  enters  and  leaves  it  through  the  liquid.  Consequently,  the 
current  through  the  wire  is  strongest  between  the  electrodes  and  near 
them,  and  becomes  very  weak  at  a  distance  from  them,  though  it  always 
flows  in  the  same  direction.  If  it  proves  to  be  true,  it  will  illustrate 
in  a  crude  manner  that  the  phenomena  of  electrotonus  may  be  explained 
upon  the  theory  that  they  are  due  to  the  nerve  acting  as  a  cored  con- 
ductor (Kernleiter,  in  (lermaiO. 

An  experiment  has  been  actually  performed  by  J.  Sosnowski1  with 
a  copper  wire  embedded  in  a  bar  of  carbon.     The  phenomena  of  elec- 
1  (Vntr;ilbl:itt.  f.  Physiologic,  \i\.  •>•'>.  April  22,  I'.tO.I. 


286 


MKDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


trotonic  currents  were  duplicated,  and  his  conclusion  was  that  elect ro- 
tonu-  i-  -implv  a  mailer  of  difference  in  conductivity,  and  not  of  polar- 
i/at  ii  'ii  i  >r  vital  pri  icesses. 

Hermann's  theory  is  i  hat  elect  rot  onus  is  due  to  polarization  between 

the  a\i.--c\  linder  and  tin-  my  el  in  sheat  h.      The  same  diagram  (Fiji.  213) 

ui:i\    M-rve  i.i  illustrate  this  if  \ve  suppose  the  fluid  to  he  a  solution  of 

•  .•  Hi  .  inc.  i  he  elect  r<>des  to  he  i>t'  /inc.  and  consequently  impolariz- 

able  ii  and    the  wire  oi'  platinum.       This  is  an  experiment 

heeii    tried,  with  the  result  that  currents  are  found 

•  i  •'•  ,  \    through  all   parts  of  the  wire  .simultaneously  and  in  the  same 

i-..     Tin    explanation   offered   is  that   there  is  a  polarization  of 

the    [>]  .    which    prevents    all    the   current    from   passing   directly 


iiductor.      Wire  in  a  troueh  of  \vatcr. 


•:•  from  the  nlatintim  and  the  nearest  electrode;  and  this  causes  a 


:   the  current   through  the  liquid  to  the  nn >]•<.>  distant  parts 


T.HE   CAUSE   OF  ANIMAL    ELECTRICITY:    AN    EXAMPLE    OF    A    CONCENTRA- 
TION CELL 

•v<>   portions  of  liquid   containing  an  electrolytic  salt   in  different 

-   '•:    conri-ii?  rat  ion    and   separated   by   a   permeable  or   a   "semi- 

membrane    form    a   cnnct-tit ration    c<ll.     The    migration    of 

^';i  the  partition  b\'  osmotic  pressure  gives  rise  to  a  difference 

I'        ii'Ui-polarixable  elect  rodi — one  not    acted  u]>on  bv 

1     placed  in  each  portion  of  fluid,  an  electric  current  will 

•         '          Ic    i-uit .  connect  inir  t  he  1  wo. 

-  '  "  !iat    \'iial  electric  curi'ents  are  ]>roduce(l  in  this 

1  he    ordinary   processes  account    for    differences    in 

•  •  enever  there  is  a  dividing  membrane.      Hut  the 

•     'pment   ol  a  difference  in  potential  at   a  particular 

"1    '  '  p  •          -  in  sp.ite  of  t  he  many  import  ant 

I-'"1."     ..       Tschagowet/.:i     ()ker-Hlom,4 

and     Hoi  ut  i  an.7   besides    the    earlier    classic 

'  '•     '      '    ' .    ' '  .'     •  and  a  host   of  others. 

1  ' c     '  I'anslal  i-i ;    from    Morui  t  au.   who   has 
-    collated    the    most    recent 


>sue-  can  only  be  considered 
i     I  '  ,ii-;irii,m-    i.C    tlic    |{()y:il    Society    of 

• 


ELECTRICITY    OCCURRING    IN    ANIMALS    AND    PLANTS  287 

principally  as  produced  by  concentration  cells  since  no  metals  are 
present.  Their  comparative  constancy  as  well  as  our  knowledge  of  the 
structure  of  the  tissues  make  it  necessary  to  assume  that  the  two  elec- 
trolytes with  different  degrees  of  concentration  are  separated  by  a 
'semiperrneable'  membrane.  This  allows  one  kind  of  ions  to  pass 
through  it,  but  not  the  other  ions,  which  consequently  accumulate  upon 
it  (Ostwald,  1S90). 

"By  'membrane'  is  generally  to  be  understood  the  outer  and 
limiting  layer  of  living  substance  of  the  simple  tissue  elements:  the 
ectoplasm,  or  the  cell-membrane,  or  the  sheath  structure,  such  as  the 
sarcolemma,  nerve-sheath,  etc.  A  difference  in  concentration  is  present 
upon  the  two  sides  of  this  membrane  when  elect  ric  currents  are  produced 
by  irritation  or  natural  activity.  This  may  be  referred  to  as  increased 
'dissimilation'  (retrograde  tissue  change  or  disintegration)  at  the  point 
of  injury,  death  of  tissue,  or  irritation.  Stimulation  is  produced  in  the 
substance  inside  of  the  cell-wall,  not  in  the  outer,  intercellular  fluid. 
It  will  be  remembered  that  the  irritated  place  always  becomes  'negative  ' 
in  the  same  sense  as  the  zinc  in  a  voltaic  cell  (really  electropositive). 
Consequently,  it  must  be  negatively  charged  ions  or  anions  (ions  which 
travel  toward  the  anode)  that  are  liberated  by  the  increased  retrograde 
tissue  changes  and  press  upon  the  limiting  membrane  from  the  inside 
of  the  tissue-cell  which  is  impervious  to  them.  The  positively  charged 
ions  or  cations  liberated  at  the  same  time  are  free  to  pass  in  every 
direction  from  the  altered  place,  passing  readily  through  the  cell-mem- 
brane into  the  enveloping  liquid,  described  below. 

"It  must  be  remembered  that  free  acid  results  from  the  death  or 
activity  of  muscle  or  other  tissue,  and  Waller  and  Boruttau  have  called 
attention  to  the  fact  that  various  modifications  of  the  current  of  action 
in  nerves  during  activity  are  analogous  to  those  resulting  from  the  action 
of  carbonic  acid.  Tschagowetz  has  attempted  to  calculate  the  electro- 
motive force1  from  the  probable  concentration  of  the  carbonic  acid  in 
the  tissue-cells,  and  found  an  electromotive  force  corresponding  quite 
closely  with  the  observed  electromotive  force. 

"But  the  process  can  hardly  be  as  simple  as  would  be  represented 

by  the  mere1  statement,  that   II  cations  are  freely  movable,  while  the 

CO.,  anions  cannot  pass  through  the  limiting  membrane.  Living 
albumin  contains,  for  example,  alkaline  salts  in  loose  combination,  and 
it  seems  capable  of  itself  acting  as  an  organic  acid.  And  by  its  disinte- 
gration metallic,  ions  may  appear  as  cation-  and  complicated  albu- 
minoid products  as  anions.  which,  on  account  of  their  complex  molecular 
structure4,  cannot  pass  through  the  'membrane.'  Then,  again,  a 
demonstrable  acidification  does  not  necessarily  indicate1  an  actual 

excess  of  II  ions. 

"Waller,  in  his  book  '  Kenn/eichen  des  I.ebens'  ('Characteristic 
Kvidences  of  Life'),  goes  somewhat  too  far  in  speaking  of  an  (electric) 
solution  pressure  (or  osmotic  pressure'  of  the  protoplasm,  llns 
expression  has  so  far  been  applied  only  to  metallic  salts;  and.  besides, 
that  it  wotdd  be  necessary  to  limit  it  to  the  cations. 

"The  'positivity'  for,  more  properly,  'electronegative  behavior  > 
accompanying  increased  assimilation,  as  in  the  positive  after-fluctuation 
and  in  anele'Ct  rot  onus.  etc..  can  be  explained  only  on  the  theory  that 


MKDH  AL    KLKlTKU'ITY    AND    KONTGKN    RAYS. 

tiu-  local  concentration  is  diminished  by  the  .-ynthetic  process,  or  that 
the  cation-  which  do  pa--  through  the  'membrane'  are  repelled  in  eon- 
.-equeiice  of  tiie  proximity  of  an  anode. 

"Oker-Blom    and    Macponald.    besides    Tschagowetz,    have    sought 

',i  find  ;:  ;  litional  evidence  in  favor  of  the  concentration  cell  theory  as 

accounting     for     the    demarcation     current.1      They     applied     different 

h  \-p.it  :   h\  pert  on  ic  -ol  u  I  ions  to  a  muscle  and  to  us  t  raiisversely 

cut   vir'ace.  and  t  hen  tested  t  lie  d  ilTerei;ce  in  potential,  using  unpolarix- 

:ible  >.       t  >ker-Blotu    concludes    that    the    concentration    cell 

arisi  -  : :  mi  t  he  alterat  iou  m  i  he  t  issue;  while  Mac  Don  aid  and  Bernstein 

[e    that    a    difference    in    concentration    was   previously   existent 

be-weeii   the  |>rot  oplastn  and  t  he  enveloping  tluid  and  when  there  is  an 

iis  difference  in  concentration   is  conducted  at  onlv  one   place, 

•    [•  .  mil  • :  -    niedi  mi  of  i  he  '  men  i  bra  ne.'      Hot  li  of  tliese  aut  hors  prefer 

ue '  theorv  to  the  alteration  theor\  ^      But  this  cannot  satis- 

;':  ct  >rilv  account  for  the  current  of  action  inlluenced.  a>  it  is  by  narcosis 

tat  imie. 

"The   theory   of  a   protoplasmic   limiting   'membrane'   is  of  funda- 

::.••.•;,'.    ini])onance    in    accounting    for    local    differences    in    potential. 

-   fi  '•  .   mjurv.  secretion  cui'rents.   blaxe  currents,  and  it   is  also 

!iecc>sar\    in  the  case  of   everv  extension  and  progress  of  differences  in 

ic    potential    where    the    alteration    theory    alone    is    insufficient 

"  I'    is  necessary  to  assume  the  existence,  besides  the  limiting  '  mein- 

•.'  of  an  enveloping  liquid,  which  normally  is  isosmotic  with  the 

eel]     contents.      There    are    also     librillary    structures    which    conduct 

inscle     tibrilla   in    the   sarcoplasma,    netirofibrilla    in    the  axis- 

;•  ."  liquid,  etc.      There  are,  consequently,  structures  which  possess 

a  cert  am  analogy  t . .  t  he  polarized  nuclear  conduct  ing  models  wilich  were 

•  much  used,  as  in  demonst  rat  ions  of  t  he  elect  rot  on  ic  currents 
iii  nerves,  etc.      The  r<  semblance  is  to  t  he  extent  that  the  local  equaliza- 

.  >n  o]  concent  rat  ion  difference  and  of  potent  ial  difference  (local  current  i 
thin^  i  i  t  ake  place  in  the  adjacent  t  issue,  etc.      In  other 

-  Hieor\    oi    nuclear  conducting  libnlla   and  a   limiting  mem- 

n\'elopmg   liquid   explains  the  wave-like   progress  of  the 

•  •.  I  he  con  current  wave  of  contract  ion.  and  probably 

'irn-ss  oi  tissue  chaiiires.      The  limiting  meml)rane  theory 

11  '  lieory,  S.  T.)  furnishes  t  he  key  to  the  understanding 

>n   «!   stimuli   upon  elect I'ochemic  principles. 

r    '     be   said    here   about    the    mat  lniniat  if   calculations, 

•••:.    only    polarixecl    nuclear  fniiiluctiirs  of   IFer- 

f'remt-r.  but  they  an- still  in  an  incomplete  state. 

ol     the    extrapolar    elect  rot  (inic    currents    is    dhvctlv 

ft  ract  ion  or  repnlsioji  of  the  ions  of  the  envelop- 

1     ''•'".      elecll'ode-     ;ilid     t  1  ie    -e  m  i]  M  -1'lliea  b]  e    cl  i  a  fact  el' 

i  he  ii  ore  resist  ani    i-   i  he    membrane,    t  he 
-    greatest    in   m(-dullated  nerves,  and  least   in 

Significance     of     the     "Alteration     Negativity."     "Regions    of 
become  'negative'    m    consequent'    ,,f  the 


ELECTRICITY    OCCURRING     IX    ANIMALS    AND     PLANTS 


2x<) 


greater  permeability  of  the  limiting  membrane  to  the  cation.-  than  to 
the  anionic  part  of  disintegration.  This  has  a  clo>e  relation  to  the 
general  laws  governing  electrical  stimulation.'' 

Tchiriev's  Results  in  the  Study  of  Muscular  Currents. — A  mosi 
accurate  and  complete  series  of  elect roinetl'ic  measurements  recorded 
photographically  has  been  made  by  S.  Tchii'iev  at  Kiev.  Kussia.1  and 
his  conclusions  are  worthy  ot  consideration. 

One  of  his  photographic  recnrds  is  reproduced  in  Fig.  214.  Three 
tracings  are  shown:  d.  registering  tlie  time,  each  ascent  and  descent 
lasting  ()..'-> 75  second;  /;.  the  myogra])hic  curve;  and  c,  the  elect roinet He 
curve.  The  gastrocnemius  muscle  of  a  i'rog  was  not  detached  and  tin- 
blood  circulation  was  undisturbed,  but  the  muscle  was  more  or  le.-s 
injured  in  connecting  it  with  the  myograph.  Two  non-polarizable 
electrodes  connected  the  muscle  with  the  capillary  electrometer  which 
showed  a  current  of  rest  equal  to  0.105  volts. 

This  was  compensated  according  to  duBois-Ileymnml's  method.  The 
sciatic  nerve  was  stimulated  /'//  .W///  by  isolated  induction  shocks  ('cur- 
rents from  an  induction  coil  produced  the  opening  and  closing  of  the 
primary  current)  at  the  rate  of  11  opening  shocks  a  second.  The 
myograph  indicates  an  incomplete  rhythmic  tetanus. 


_:    stimulation  l>v  isolati'il   ini  luc- 


Fic.  L'14.— Mvographic   and   electromofrii1  r-urvrs  ilunns: 


The  elect  ro'metl'ic  curve  which  is  the  special  subject  of  th.is  study 
does  not  show  itself  like  the  teeth  of  a  comli  as  dnHois-Reymond  sup- 
posed. I'nder  the  influence  of  each  stimulation  a  wave  of  negative 
electrical  potential  traverses  the  muscle  and  the  waves  «>t  negative  varia- 
tion succeed  each  other  s< >  rapidly  \vith  stimuli  applied  at  tin-  rate 
mentioned  that  they  overlap.  The  potential  or  voltage  has  not  nearly 
reached  the  zero  point  before  the  next  \vave  arrives,  1  he  I'esull 
curve  somewhat  resembling  :i  (iigln  ni  -  ;•-.  The  vertical  distances 
in  the  chart  marked  o.  10.  20.  and  up  to  ion  :tre  millivolts. 

The  elect  roineiric  curve  i-  sometime-  like  the  teeth  of  a  saw. 

The  potential  is  sometimes  reverst-d  -  •  i         'he  curve  is  belo\v  tin    axi 
of  abscissas   instead   of   ab<»ve   i1 .      The-  lions   occur    in   different 

states  of  the  muscle  depending  upon  di  '  its  surface  from  c\po<uiv 

to  the  air  and  the  condition  of  the  ciivula  imi  in  it. 

1  .luiinuii  tic  \\i\-.  ili)4ii«'  t-t  il"  1'athnl  .-ri    '  >  •.  vt>l.  vii.  p.  .V.i:  . 

19 


MKDK  Al.    KLK<  TKH  ITY    AM)    KOXTGEN     KAYS 

The    various    photograph-    corroltorale    Ilelmholt x's    and    Bezold's 

oh.MTvati'iii  that   the  negative  variation  in  the  muscle  begin-  before  the 
rnu.-cular  linn.      I'.ach    negative    wave    lasts    longer    than    the 

contraction    which   accompanies   it,   and   torms  a   continuous 
rlir\  e    with    t  he  Micceei  ln.g   \\  a\"e. 

!"•.,•  in-  .,._':.  phjc  !•  . :  •  e  falls  ver\    rapid!  v  alter  shutting  off  a  current 
.     :    [elanus.  iiut   the    elect rometric    curve   may 

even  >ho\\    an   immediate  rise,  and  it.-  fall  is    always    slow  and    gradual. 
:          ,,••    -   coiiclu-i"n    iii    regard   t"   muscular  currents   is  that    negative 
and    :    '.-    ..  n    -    'litraction   dn  not    depend  upon  one  another, 
: ,  ,  •     ipMi     ;    n»mm»n  caiisi       I  he  st  imulation  of  the  muscle. 

Tchiriev's    Conclusions    in    Regard  to  Bio-electric    Currents.— 

i .     1'he  living  ai    ;  perfect ]\  in  t  act  t  issues  and  organs,  for  exam  [tie,  nerve, 

rt .    d"    not    show   even    slight    currents   or   difference   in 

r     .    ;   jicissihlv   be  considered  as  playing  a  role  in  the 

i]  i  heii  functions  or  in  t  he  activities  of  the  general  system. 

_'.    1'he  --:.:  ,e   tissues  show   a   difference  in   potential   when   they  are 

i  ired    pan     is    negative    to    the   uninjured    part.     The 

it    -     rf ace  of  a    muscle  or  a   nerve  is  negat  ive  to  t  he  longi- 

.       ;:    ••  •      •:    t  lie    tillers. 

:;.   Tiie    .mirces  of   this  elect  roinot  i\'e   force   are   preexistenl    in   the 
•.--.<-.      This  is  shown  hy   (n  )   The  difference  in  potential  when  injured: 
the  various  phenomena  of  elect  rot  onus;   (r)   the  electric  organs  of 
•  :  •    in  fishes. 

I.    Sn  mu  la  t  i<»n  of  intact  t  issues,  such  as  nerves  and  muscles,  produces 
[«i     -.  '!  'trie  '  ffects.  but  not  a  trace  of  change  in  electric  potential. 

."i.    1'    ''.••        isc]e    or    nerve    has  been    injured   and    hence   gives   an 

ic  current  ot  its  own.  -'  imulat  ion  will  t  hen  produce  an  electric  effect 

in   addition   to   the   physiologic  effect   of  contraction  or  other  activitv. 

electric   effect    j~   purelv   a   physical   one.   a   negative  variation,   and 

usciilar  current    proper,    and    the   fresher   and    more 

'    •    t  is.-  ies.   the  stronger  is  this  negative  variation   result  ing  from 

n.    1  lie   m  >de  o|   production  of  this  negative  variation  seems  to  be 
sniin-es  of  electromotive   force  undergo   a   change   in 
ill    act     inure    feeblv.       This    depeniU    upon    a 
'tiseOjUenlly  muscle,  on  account  of  rigor  mortis. 
•'^  •••'   '"   '.'anal  ion   when  stimulated;  but    nerve 

in    and    negative   variation    are   independent    of 
; 

'''••I    ;iloi!Lr    intact    ner\'e-fibers    independ- 
piitenl  ial.        There  is  no  elect  ric 
rtace  Hi    i  he   in  t  act    brain    when 
i'i  d. 

'he     iH'rve    supplying    an     uninjured 
1    '  '     its    c] rcnla t  ic  >n    un im- 
'  •  '•  c  irrei  is.     There  may  be 
'  e'  anus.       I  here  i-  en  her  no  elect  He  change  or 
/     •  ..;   le^   tha:,   n.nul    millivolt. 

I".     M-;  ,  '      ,.  i,      r,-,, 


ELECTRICITY    OC(  I'KRINq    IN    ANIMALS    AND    PLANTS  291 

been   flowing  for  a    long  time.     The   result    in   any  of  those  cases  is  a 
tetanic  contraction  of  longer  or  shorter  duration. 

Tho  electrocardiogram  is  a  graphic  tracing  of  the  electric  currents 
produced  by  the  contraction  of  the  heart  muscles;  has  become  an  im- 
portant factor  in  cardiovascular  diagnosis.  (See  page  :>2;V) 

11.  Spontaneous  tetanus  and  tetanus  as  seen  in  voluntary  muscular 
contraction     is     a     complete     non-rhythmic     continuous    contraction. 
Rhythmic   tetanus   is   produced   only    by    rhythmic   stimulation   of   t,he 
nerve  or  muscle. 

12.  An  injured   muscle  giving  a  current   of  rest    may   be  caused  bv 
rhythmic    stimulation    to    exhibit    marked    steps    or    dentitions    in    the 
electromet  ric    curve    of    the    negative;    variation.      This    may    produce 
tetanic  contraction  in   muscles  of  the  other  leg  whose;  nerve  has  been 
placed   along  this   muscle,   just    as  if  the  stimulated   muscle  yielded   a 
faradic  current. 

b>.  Injured  tissues  and  organs,  ('specially  muscles  and  nerves,  show 
certain  electromotive  changes  when  performing  physiologic  functions, 
but  it  does  not  follow  that  these  electric  properties  which  are  inherent 
in  the  tissues  take  any  more  direct  part  in  physiologic  aetivitv  than 
the  other  physical  and  chemic  properties  of  the  tissues. 

14.  Kleet  rot  onus  of  a  nerve  is  not  a  process  of  polarization  in  the 
ordinary  sense  in  which  that  takes  place  in  inorganic  substances,  }>ut  '* 
due  to  a  displacement  of  the  sources  of  electromotive  force  in  the  n'rfVe 
itself  under  the  influence  of  the  constant  current. 

These  are  the  deliberately  formed  opinions  of  a  man  who  has  made 
wonderfully  careful  measurements  of  the  actual  electric  conditions 
accompanying  physiologic  activity.  He  does  not  think  that  under 
normal  conditions  there  are  electric  currents  of  sufficient  intensity  to 
be  the  causative  factor  in  physiologic  adivitv.  He  thinks  that  the 
infinitesimal  currents  which  are  normallv  present  are  only  a  part  of  the 
general  chemic  and  physical  changes  occurring  in  living  tissues,  and  are 
not  the  sole  and  regulating  causes  of  activity.  According  to  his  view. 
physiologic  currents  of  electricity  are  phenomena,  not  causative  factors 
of  muscular  contraction  and  of  transmission  of  nervous  stimulation. 

If  these  views  are  correct,  it  would  still  remain  true  that  elec- 
tricity artificially  applied  is  one  of  the  most  effective  means  of  exciting 
physiologic  activity. 


PHYSIOLOGIC   EFFECTS  OF  ELECTRICITY 

PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY   UPON   MICROORGANISMS 

Galvanotaxis    •  ••••  •  en  ,    current  of  electricity  passes  through  a 

;m      isUall'  •    small   living  organisms  tend  to  move 

•'•.'•  electrode  under  the  influence  of  the  current. 

ft-:    ;•  •.•••     >;   ;    living  organism  to  arrange  its. -If  so  that  its  long 

a\i-  ::.   relation,  either  parallel  or  at  a  right  angle  to 

the  direction  of  the  current,  i-  called  ciahnnotaxis.     It  is  analogous  to 

;•<    v.;<,\    in  \\\  :.  i.  a  shoal  of  small  fishes  will  all  head  the  same  way. 

swimming  anain-t  the  current  which  is  carrying  them  along  in  a  brook. 

Ti  -          i-operties  ;;iv  exhibited  by  living  organisms  of  different  sixes. 

c  insist  of  only  a  single  cell.      1'rotoxoa.  infusoria, 

•    .   •     ip   h  -  ''.•  v n   used   in   many  experiments. 

—  ms  to  permit  of  a  purely  physicochemic  explanation 

:;-•    •  •    :.ecess;!;-il\    :i   \:';;1   phelii  itnelion.      A  cell   n  iay  act  |U  ire  an  elect  1'ic 

ifg"       •      '    ••  unequal  peneti. ition  of  ions  of  different  sixes  (positive 

•    '  'Ugh    its  enveloping   membrane.     This  depends  upon 

r  cter  of  1  h'.-  membrane,  and  the  osmotic  pressure 

•      •  •  •  '    •!!  of  t  he  posit  ive  or  negative  ions  inside  the 

'    •-  •  '•••'  :••'!•.  '  !<•  solut  ion  in  which  it   lies.      A  cell  which  has 

:>->s!?ivc  electric  charge  '.vili   be  attracted  toward  the 

•     •••' •  •.      and  one  with  a  negative  charge  will  tend  to  move 

!>"s':tivi   elr-rtrode.      A.  Coehm  and  \\'.  Barrott1  have  studied 

'."     ' '    galvannt  axis   from    this   point    of   view.       1'aramecia. 

i:.:'us,,ria,    -wim    toward    the    cathode   when    in    a    dilute 
;.       Hut    r    is  not   so  simple  a   matter  with  11-1, 
ials,  where  the  central  nervous  system 
\     '.":    us    n  its'    lie  calleil   into   pla\\ 

Galvanotropism    :      still    more    complicated,    and    seems   decidedly 

tissues  and  not  a  mere  physical  effect 

''"  matter.      It  is  the  growth  or  bending  of  a  living 

th   ;i    galvanic  current .      It    may  be 

house-plant  toward  a  lighted  window.     The 

-    '•    and    1  idlof'i   ha\'e  been  supplemented  by 

li-hing  between  galvanotrojiism 

•"  pn  upon  infusoria  from  chemic  changes 

les. 

I'.    <t:i'  kewiisch3   slmw   the 

1  '  •  •;•  :i:g  currents 
'-  '  :•  cing  tin  ivement 

'    n    of    'the 

M\is.        These 

'  "i  t  hi-  p  in.  when 


PHYSIOLOGIC    KFFKCTS    OF    ELECTRICITY  293 

the  current  is  of  incdiuin  strength  and  medium  frequency  of  alternation. 
Some  organisms,  like  Stylonychia  mytilus,  show  transverse  galvano- 
tropism  with  quite  slow  alternations  of  tho  current,  and  in  this  par- 
ticular case  the  peristome  is  directed  toward  the  cathode.  Any  given 
species  of* protozoa  presents  different  stages  and  types  of  galvanotropism 
and  galvanotaxis  with  different  intensities  of  the  current.  According 
to  Stat kewitsch's  observations,  proio/.oa  which  are  fixed  upon  or  near 
little  solid  masses  exhibit  much  slower  ;md  less  energetic  galvano- 
tropism  and  galvanotaxis  because  of  the  effect  this  obstacle  has  upon 
the  current.  He  believers  that  galvanotropism  is  an  active  process,  not, 
to  be  explained  by  eataphoresis  i>r  any  purelv  physical  theory.  It  is 
noteworthy,  however,  that  inorganic  particles  may  exhibit  motion  under 
the  influence  of  the  same  current ,  and  this  is  sometimes,  in  the  opposite 
direction  from  that  taken  by  pr«toxoa. 

Microorganisms  undergo  changes  in  shape  and  consistence  under 
the  influence  of  an  electric  current  passing  through  the  medium  in  which 
they  lie.  The  ameba  puts  <>ut  projections  from  the  cell-body,  pseudo- 
podia,  toward  the  anode,  ami  undergoes  granular  degeneration  when 
too  strong  a  current  is  applied. 

It  appears  to  the  author  that  these  different  phenomena  have  partly 
a  physical  and  partly  a  physiologic  basis:  that  there  are  the  direct  effects 
of  ionizutiou,  secondary  chemic  changes,  cataphnresis,  and  heat  upon 
the  substance  of  the  organisms,  as  well  as  the  indiivct  effects  excited 
in  the  organism  by  these  actions  of  the  electric  current. 

Schatzki1  has  experimented  with  a  variety  of  pathogenic  micro- 
organisms, especially  noting  the  effect  at  a  distance  from  both  poles. 
He  found  that  galvanic  currents  of  from  L'o  to  :;o  milliamperes,  applied 
for  from  one  and  one-half  to  two  hours,  completely  abolished  the 
virulence  of  these  microbes;  succeeding  generations  from  microbes  thus 
galvanized  possessed  less  vitality  as  to  virulence,  as  to  activity,  and  as 
to  growth.  The  medium  through  \\hiVh  the  current  was  passed  was 
contained  in  a  glass  tube  1  cm.  in  diameter  and  'JO  cm.  long. 

PHYSIOLOGIC  EFFECTS  UPON  VERTEBRATE  ANIMALS 

The  most  important  part  of  th'1  effect  uf  low-tension  currents — 
up  to  110  volts — is  upon  the  heart.  There  is  a  fibrillary  tremor,  an 
irregular  fluttering  of  the  ventricles,  \vhile  the  auricles  continue  to  beat 
regularly.  This  has  been  studied  by  applying  induced  currents  to  the 
exposed  heart  of  different  animals.  The  exposed  heart  of  a  dog  never 
regains  its  rhythmic  beat  after  fibrillary  tremor  has  been  caused  bv 
induced  currents.  The  exposed  heart  in  an  adult  guinea-pig  can  be 
revive' I  with  difficulty  by  cardiac  massage  and  artificial  respiration. 
A  rabbit's  heart  usually  revives  spontaneously.  The  rat's  heart  revives 
as  si  mil  as  t  he  current  is  turned  .  >t'i . 

There  is  the  same  effect  upon  the  heart  when  low-tension  alternating 
currents  are  applied  to  the  un<>|  erati  t  :  h  rough  in  out  h  and  rectal 

elect  rodes. 

The  electric  resistance  in  a  dog  weighing  twelve  to  twenty-foiii 
pounds  is  from  'J">o  to  :!.~>o  ohn  s,  ;  Iternating  current  of/' 

f«r  f<v    s/mrn/s  sometimes   causes  a  cr\   of  pain,  or  sometimes  in 
beyond  a  slight  rise  in  blond-pressure, 

:  1'iulli'tin  ofiirirl  ilc  In  Socii-tr  fiMii./ai-  •  •!   I  .'"<"(  r»t  luTapir.   lM'«'iuh.T,   I'.'ii; 


•_><)}  MKDICAL    KLKCTKieiTY    AND    RONTGEN    RAYS 

Ten  volt-  for  ten  second-  -onietimes  interrupts  the  cardiac  rhythm 
and  -ometime-  causes  fibrillary  tremor  of  the  heart  and  death. 

Ten  volt-  for  two  seconds,  with  the  pneumogastric  nerve  severed, 
caii-e-  death  by  fibrillary  tremor  of  the  heart. 

Ue-piratioii  i-  interfered  with  in  all  the  above  cases  by  a  general 
nmdiiion  of  mu-ciilar  contraction,  -tetanus,  but  becomes  reestab- 
lished as  soon  as  the  current  is  turned  off.  Respiration  gradually  fails 

•  ran    is  permanent  1  v  paralyzed. 

\.        .     ,      UK  ,-urrent  of  ti-om  20  to  40  volts  produces  the  same  fatal 
...  ,i   requires  onh    a  second  or  two  of  contact.     Convulsions  are 

-  ,[,[,  ,;    ;in,l  the  animal  is  in  opisthotonos  or  generalized  tetanus  lasting 
five   -ecunds   after   the   current    is   turned   oiY,    and   followed   by   clonic 

(HI. us     which     irradually     cease.      Respiration     which     has     been 

,,,  d    > ,   i  lie  tetanic  coi it  ract  ion  recovers  and  continues  for  quite 

if   time.      Sensation    is   not    much    affected.      The  corneal    reflex    is 

pi-i-erved.      Death    results   from    almost    instant    cardiac   paralysis,   but 

•  ,     other   functions   of   the  living  organism   continue  for    a    time   and 

lallv    die   nut    as   a   secondary    consequence   of   the   failure   of   the 

,\n  ;  It  i  •  •  a  ting  current  of  from  si)  to  120  volts  applied  by  electrodes 

•  .    ipoi    the  shaven  head  and  the  shaven  left  thiirh  for  at  least  one 

iduce  the  same  results  as  have  just  been  described  for  currents 
ill    20   '  •    i(|   volts.      The   resistance   in   the  case  of  electrodes  upon  the 

md  1  hiirh  is    li  H I  i  ihms. 
Tiie  paralvsis  of  the  heart  occurs  at  once  in  all  these  cases,  but  the 

;i! l-pressure  shows  an  initial  elevation,  followed  by  a  trradual  decline. 

Pi  '  \    -•    and    Hattelli   attribute  this   to   vasomotoi1  stimulation   in   both 
arteries   and    veins,    -lowing   the  passage  of  blood   through   the  arteries 

•  the  heart,   and  pressing  it    through  the  veins  toward  the  heart. 
The   thorax  bem^  opened,  the   ventricles   are  seen  in  some  cases  to 

•late  of  fibrillary  tremor,   while  t  he  auricles  beat    regularly  for 
•  v  ••     lift een  minutes. 

alone  does  IK  it  do  any  good,  but  cardiac  massag< 
•  pi rat  ion  combine,  1  keep  t  he  animal  alive  as  long  as  t  hey 
:.       Dunn'.;  this  period  sensibilitv  is  normal. 

\    '•..         '     tpplied    by   electrodes   placed    upon    the   two   sides  of  the 

i!  !'  :•    ;  a  resistance  of  '_N)  in  .'ii'D  ohms.      Ten  volts  applied 

me  do'_r.   while  two  others  survived.      <>ne  of  the 

:  c  irn  r. '  o|    I .")  vn|ts  applied  for  five  seconds. 

'tended    i  he   application   of  the  electrodes   to   both 

Summary   of   the   Effects  of   Low-tension  Alternating  Currents 

up  to  120  Volt:-'.       !  '  .    •    are  >li<_rii!   /,,  /  ,•,,,,.-  ,i;.-.-tnrh<i n<-<  .s-  in  dogs,  guinea- 

b'e   [iii'ai  ion    i-   i»nl\    lenijn  irarilv  arrest eil,  and 

'   ,  '  i'ected.        Twent  \      \'i  i|t  s    will     produce 

'  hot  onus  n   i. in    n|   i  he  eli  •(••  ri  M  !i  's  is  a])])lied  t  o 

l'>l  I    \'i  <!'  -    a  re    n-qu  irei  1    when    hot  ll    elec- 

li   :.!>-.       The    effer!     upon    !  he    fndft    is    to 

;  :'':  .      -    previously    explained,    is    fatal    in 

:  '-co1  i  red  :  I'oin  in  nt  hers.      //•  .-  [linilioi}  is  not 

1      :  i-rs  or  Liuiiu  a-pigs,   and   in 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  20") 

the  electrodes.  This  is  the-  e-ase1  when  one-  elee-trejde  is  applieel  to  the 
animal's  head  and  the-  other  to  the  thigh,  or  when  one  is  placed  over  t  he- 
cardiac  region. 

Preliminary  section  of  the  pneunmgastric  nerve  has  no  effect  upon 
the1  production  of  fibrillarv  tremor. 

Batte-lli  considers  it  probable  that  fatal  effects  from  low-tension 
currents  in  man  are;  produced  in  the-  wav  de-tailed  above,  vi/..  bv  primarv 
cardiac  paralysis. 

The  Effect  of  High-tension  Currents.  A  current  of  ±20  volts 
in  the  e-ase  of  the  rabbit,  or  ">")()  volts  in  dogs,  doe-s  not  produce  fibrillarv 
tre-mor  of  the-  he-art  or  death  by  primary  cardiac  paralysis.  There-  is 
only  a  te-mporary  arrest  of  the  auricles  from  stimulation  of  the-  pneumo- 
gastric  nerve.  Respiration,  on  the  contrary,  is  impaired  by  an  effect 
upon  the  respiratory  center  in  the  medulla.  This  effect  may  varv  in 
elegree.  Respiration  may  be-  spontaneously  renewed  after  the  current 
has  ceased,  or,  if  it  doe-snot  ret  urn  of  itself,  it  may  be  readily  brought 
about  by  artificial  respiration. 

Shocks  from  currents  of  this  voltage  are  not  ordinarily  fatal  if  the 
proper  treatment,  artificial  respiration,  is  applied. 

The  Effect  of  Very  High-tension  Currents.  Currents  of  from 
1000  te>  10.000  volts,  as  cmploye-d  in  the  long-distance-  transmission  of 
poAver,  produce;  mechanic  lesions  of  the  tissues  traversed,  just  as  light- 
ning does.  Fatal  hemorrhages  in  the  substance-  of  the-  central  nervous 
system  may  cause  irreparable  paralysis  of  respiration  and  other  functions 
(Jellinek).  The;se  very  high-tension  currents  are-  often  instantly  fatal, 
but  the;  e-ffect  varies  greatly 'with  the  path  traversed  by  the  current  in 
passing  through  the  body.  If  the  heart  and  the  central  nervous  system 
are1  not  in  the  direct  path  of  the;  curre-nt ,  t  hey  may  rece-ive  only  a  fract  ion 
of  the'  original  current,  and  the  effect  may  correspond  tot  hat  of  a  medium 
or  low  voltage.  The-  reve-rse  is  true  as  to  low-tension  curn-nts  applied 
directly  to  vital  organs. 

From  90  to  11")  volts  have  killed  men  by  cardiac  paralysis  under 
exceptiemal  conditions  as  to  electric  conduction.  On  the-  other  hand, 
in  a  case-  which  came  to  my  own  knowledge,  a  shock  from  a  2200-Voll 
alternating  current  was  survived,  with  no  permanent  damage-  e-xcept  a 
dee-ply  grooved  scar  of  the;  hand  and  a  fairly  well-united  fracture  ot 
the  femur. 

Legal  electrocution  bv  means  of  an  alternating  current  of  from 
l.'!()0  to  1700  volts  is  not  always  immediately  fatal,  because-  it  aims  to 
produce  respirator}"  paralysis,  and  it  some-times  requires  three  or  tour 
applications  to  make  this  paralysis  permanent. 

1'revost's  animal  experiments  show  that  a  heart  in  which  fibrillarv 
tremor  has  been  induced  by  a  current  of  .">(  i  volts  may  sometimes  be 
reanimated  by  a  current  of  -isoo  volts  applied  ten  seconds  later.  This 
is  not  to  be  recommended  in  the-  treatment  of  human  beings  shocked  bv 


The  Relation  of  Amperage  and  Voltage  to  the  Physiologic 
Effect.  -Industrial  currents  for  linht  and  power,  if  alternating,  usually 
have  about  ")0  periods  a  second,  and  this  rate  is  very  active1  physiolog- 
icallv.  These-  e-urrents  have-  such  tremendous  volume1  that  contact 
with  a  conductor  carrying  a  current  "i'  MUioi)  volts  must  be  absolute!} 
guarded  atiainst.  Xo  person  must  be  allowed  to  approach  within 
sparking  distance  of  such  a  conelue-tor.  :md  no  other  conductor  must  be 
allowed  to  touch  it  or  come  near  it.  The  crnx*in<j  of  a  high-te-nsi»n 


MKDICAL    KLK<  TKIi  ITY    AND     HONTGEN    KAYS 

iy  a   wire  which   is  >uppo>ed  to  carry  a  perfectly  harmless 

-  :i  frequent  caii.-e  of  fatal  accidents.     These  industrial  currents 

•  sending  a  fatal  number  of  amperes  or  too  large  a  quantity 

[iil'ii  ;-:.   []  e  resistance  offered  by  the  animal  body. 

Harmlessness     of    High-tension     Therapeutic     Applications. — 


:..  :;_ai:».  the  very  rapidly  oscillating  high-tension  Tesla  currents 

ieca  IM'  i  he  I  raiisinission  of  ions  through  t  he  se mi] >er meal >le 

H)   tin-  electrically  conducting  human  body  cannot    keep  up 

•  .  and  so  only  a  part  of  the  potential  variations  affects 

THE   EFFECT   OF  ELECTRICITY  UPON  ANIMAL  TISSUES 

•:•"••<••-    vary   with    the   voltage   and    amperage   of   the   current 
;.  and  also  with  its  density  and  direction.     They  are  very  largely 

-is.  and.  as  in  the  case  of  an  ordinary  electrolytic  cell, 
•••':•.  evident  ;.:  the  points  of  contact  with  the  electrodes.  This 
he  moiv  certain  to  be  the  case  because  of  the  wide  diffusion  of 
••  •  '  i)  the  tissues  between  the  t  \Vo  electrodes.  Sometimes  the 

•  I      im:   effect    of   ;;li    elect  ric   discharge   is   produced   in   the 
'•>,-    '    is   •:.  .-t    he   quite  exceptional.      Lightning  splits  a  great 

•  p  '  i  bottom  by  an  explosive  effect  due  to  the  heating  of  air 
.  ;:pof  and  '  he  iraseous  products  of  elect  roly sis  in  the  cellular 

re  <>:    •''.<•  •.'. 1.      Such   an   effect    is  not   produced  upon   men  or 

•  n  iizhtning  stroke.     The  human  body  is  quite  a  good 

•  <:•    •:    electricity   as  c-ompared  \vitli  the  insulating  properties  of 

\)    .  '•'    tMii'i'ent   can  pass  through  any  part  of  the  body  or 

bout  eijiial  readiness,  whereas  in  a  tree  there  may 

••  LT    ti'aci.s    lilled    \vith    rea<lilv    conducting    moisture 

.  '.'    dry  and  consequently  non-conducting  fibers.      In 

ve  i  he  lamiliar  generation  of  intense  heat  produced 

-   hiilli    voltaire  thi'ouirh   a  conilnctor  too  small 

'i  ••  <-ase  with  the  human  bodv.  since  it   has  a 

e  hea  vii  'si  ;:  i't  iticjal  i  ir  natural  cm-rent  s. 

the  M'TVoiis  centers  in  some  cases 

1  •  '  '  -  can   hardl v  be  considered  in  the  same 

nine    liirhl  tiiiiLr    IM  -It    mav  |>l'oduce 


f.  •   a    -Ul'l  ace  elect  l'(  (lie 
'ir\'  t'roin  accident  al 
i   ie  burns  which 
>ub'     <>  due  chiefly 
i  ily  a  very 
•    electrolysis. 
i  .  "        ;     '..  :     ,•:'.  e  a  direct 
•     '       '       ••  '  •<•'  .    added    to   the 
1  '    plalinum 

liar  '.va v. 
1        lies.      !v       -   ;-.  !:••  :  •:    1,,  eject  n'citv  the 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  207 

animal  body  may  be  considered  as  an  electrolyte  consisting  of  a  >pon<ry 
mass  filled  with  a  solution  of  sodium  chlorid.  An  electric  current 
passing  through  this  electrolyte  produces  a  stream  of  sodions  (sodium 
cations)  moving  toward  the  cathode,  ;uid  a  stream  of  chlorions  (chlorin 
anions)  moving  toward  the  anode.  The,  ultimate  products  of  electrolysis* 
are  liberated  at  the  electrodes,  and  do  not  consist  in  free  sodium  or  free 
chlorin.  These  have  such  strong  affinities  that  a  substitution  reaction 
takes  place  in  the  body  at  the  two  electrodes,  resulting  in  the  liberation 
of  tree  oxygen  or  tree  acid  at  the  anode  and  of  free  hydrogen  or  free 
hydroxyl  (OH)  or  free  alkali  at  the  cathode.  The  effect  upon  the 
tissues  at  these  two  points  is  considered  later.  The  foregoing  process 
undergoes  certain  modifications  dependent  upon  the  composition  of 
the  electrodes.  If  the  latter  are  of  metal  and  are  directly  in  contact 
with  the  skin,  metallic  ions  usually  diffuse  into  the  tissties  from  the 
anode.  Anodal  diffusion  is  the  most  accurate  name  for  this  process, 
which  has  been  used  therapeutic  ally  for  the  effect  of  the  metallic  ions 
upon  diseased  tissues;  but  the  process  has  also  been  called  eataphoresis, 
because  the  movement  of  the  metallic  ions  is  away  from  the  anode, 
through  the  tissues,  toward  the  cathode,  ('upper  or  brass  electrodes 
applied  immediately  to  the  surface  of  the  skin  will  produce  a  burn  at 
the  cathode  from  the  action  of  the  metallic  ions  if  a  current  of  con- 
siderable strength  is  applied. 

Metallic  ionixation  may  be  desired  for  therapeutic  purposes,  as  in 
copper  cataphoresis  for  hemorrhoids  or  fissure.  More  often,  however, 
it  is  undesirable,  and  the  usual  method  of  avoiding  it  is  by  covering  the 
metal  with  chamois,  wadding,  sponge,  kaolin,  or  clav  moistened  with 
a  solution  of  common  salt  or  of  sodium  bicarbonate. 

Some  metals,  like  platinum,  yield  very  few  ions,  and,  used  as  surface 
electrodes  or  even  introduced  as  needle  electrodes,  yield  results  which 
are  due  simply  to  the  electrolytic  dissociation  of  the  tissues  themselves. 
Passing  a  platinum  needle  electrode  into  a  hair-follicle  or  piercing  the 
skin  itself  with  such  a  needle  and  connecting  it  with  the  negative  p"le 
of  a  galvanic  battery  while  the  positive  pole  is  connected  with  a  sponge- 
covered  electrode  held  in  the  patient's  hand,  a  current  of  one  to  two 
milliamperes  will  produce  visible  electrolysis.  The  ti>stte  becomes 
white  ami  swollen,  and  bubbles  of  uas  are  formed.  1  he  cheinic  effect 
at  the  negative  electrode  is  of  the  liberation  of  //  and  "f  Oil.  or  "f  free 
alkali,  and  this  has  a  dissolving  action  upon  albuminoid  substances.  It 
the  action  is  long  enough  and  strong  enough,  there  is  colliquativo 
necrosis  of  the  tissue  surrounding  the  needle,  and  the  latter  becomes 
loosened,  and  when  removed  is  found  bright  and  free  from  nxid. 
A  needle  electrode  connected  with  the  positive  electrode  produces  a 
somewhat  similar  effect  upon  the  tissues  swelling  and 
bubbles  of  gas.  hut  oxygen  and  free  aci 
ysis  there.  The  result  is  a  coagulation  necrosis  (from  the  formation 
of  acid  albumin),  and  the  needle  st  icks  fast  in  i  he  tissues.  A  st  eel  needle 
should  never  be  used  as  an  anode;  the  iron  ion  would  stain  the  sk  n 
indeliblv.  Such  a  needle  would  COM..'  out  badly  rusted  from  oxid;  I 
With  surface  electrodes  'here  is  a  swelling  and  edematous  condition  >  \ 
the  skin  under  the  cathode,  due  to  electrolysis,  and  this  may  be 
correctly  called  cataphorescence.  At  ''.'•  anode,  on  the  contrary,  '' 
skin  has  a  tendency  to  contrac 

The  tissues  of  the  body   for 
uniform    electrolyte    when  spon 


Hi    a:v    u.-ed.    and  the    products  ut'  electrolysis  arc  found  at  first 

•  K    -all    solution   clo-e  to   tin-  electrodes.      If  the  current   continues 

;  rect  ion,  a  secondary  effect  becomes  evident  after  a  time.      Tin? 

u' :••:;'  re- 1st  a  nee  at  I  he  surface  of  t  lie  body  and  the  complex  character  of 

;•-   cjn-n  ic    composition    make   the   point    of   contact    between   the  salt 

>o]  itj  •  !!    and   the  skin   correspond   closely   with   the  line  of  separation 

between    tl»e   water   and    the    salt    solution   in   the  experiment    below. 

or  alkaline   radicles  are  liberated  at    the  surface  of  the  skin,  and 

may  produce  a  severe  effect.      .Means  of  avoiding  this  are  by  changing 

the  direction   of  the  current    from   time  to  time,   and  by  occasional!} 

rii  simi  out   the  electrode  with  fresh  solution.     The  palms  of  the  hand 

are  most   resistant   to  any  such  effect,  but  the  skin  of  any  region  where 

t  he  ep  idem  i  is  is  thin  may  be  irrit  a  ted  or  even  "burnt  "  by  the  products 

dmlvsis.     This  is  one  reason   tor  the  employment  ot   very  large 

electrodes  when  strong  currents  are  to  be  applied.      A  given  strength  of 

current    expressed    in    milliamperes  will   produce  the  same   amount   of 

.-.:.::'•  whether  it  pas.-es  through  a  large  or  a  small  conducting 

When  the  surface  of  contact   with  the  skin  is  a  large  one,  the 

.--edion  of  the  conducting  path   is  correspondingly  large,  and  the 

'-    if  the  chemic  changes  are  so  diluted  that  they  may  be  carried 

the  circulation  of  the  blood  and  lymph  without  producing  an 

'     '      '  :.';LT    local     effect. 

The  :  alter  is  one  of  current  density,  and  is  similar  to  the  difference 
'•'•••  een  the  -low  combustion  which  takes  place  in  the  whole  human 
ii  ;  ••••:  produces  a  certain  amount  of  carbonic  acid  (CO.,)  each 

.'     I'ai-im:    the    temperature    above    i)s>..">°    F.       The    same 

i    '   of  combust  ion  producing  t  he  same  amount  of  ('().,  per  minute  in 
.-•  fintrer-t  ip  would  be  accompanied  by  a    painful  and  destructive 

itli  a  local  temperature  far  above  the  normal. 

\n  example  oi  secondary  actions  is  found  when  an   electric  current 
- 'I1  i'  ion  of  sulphate  of  copper.      The  salt  is  separated 
-  deposited   as  copper  plating  upon  the  surface  of 
'    electrode,   and   ;iu  acid   radicle  which  goes  to  the  positive 
adiHe  combines  with   the  hydrogen  of  the  water 
'•    oi  copper  ;-  dissolved,  and  forms  sulphuric  acid. 
'1    the  •    ater  i-  liberated  as  bubbles  of  gas.       Klectrol- 
'e  .it    -odium    tui'inshes   the  same  secondary 
the  formation   of  sulphuric  acid  and  the 
secondary  action  takes  place  at  the 
owerful  affinities  that  metallic  sodium 
e.   l)in    it    at    once  coml)ines  with  the 
iri'l   idi-  liberate-  bubbles  of  hydrogen  tras. 

"  i  'i "  '  '  '    '    •    prima  ry  pi-i  .ducts  are  capable 

1    '  li-l     lice  of  1  he  elect  rodes. 

v-i-    appear    only     at       the    electrodes    and 
t  he    lat  1  er    is    homo- 
currenl    has    to   traverse 

'    foul  ainiiiir    t  >lain  water 
'    'In-    bottom,    the    whole 
•  •     '  '  •    '-'I    rent    pas-es   from   above  down- 

'  liquids,   indi- 
•i'l-      I'1'1-''  •    cm  n  t:'    v,  ill    result    in 


PHYSIOLOGIC     KFFKCTS    OK     KI.KCTHICIT  Y  2W 

a  bine  color,   indicating  the  liberation  of    a  base  or  an   alkali   at    the 
junct  ion  of  the  two  liquids. 

J'olarizdtion  also  takes  place  at  the  line  of  separation  between  tin- 
two  liquids,  and  may  be  demonstrated  if  the  original  electrodes  are 
removed  alter  the  current  has  been  flowing  for  some  time.  The  original 
electrodes  may  be  removed,  and  another  pair  which  are  connected  with 
a  galvanometer  may  be  placed  in  the  two  liquids.  A  current  will  at 
once  begin  to  flow  in  the  contrary  direction  to  the  original  current. 

Transportation  of  M fitter  />//  the  Electric  ('nrrc'ni. — A  solution  of 
sulphate  of  copper  in  a  glass  vessel  and  an  inner  porous  jar  will  tend  to 
assume  the  same  level  in  both  of  the  jars,  but  if  copper  electrodes  un- 
placed in  the  two  jars  and  a  current  of  electricity  sent  through  them, 
the  liquid  will  be  carried  toward  the  positive  pole,  and  will  assume  a 
higher  level  in  that  jar  than  in  the  other.  The  stronger  the  current, 
the  greater  the  difference  in  level  will  be  maintained. 

Another  striking  demonstration  is  made  by  passing  a  current  of  elec- 
tricity through  two  jars  containing  an  anilin  dye,  and  between  which  is 
an  inverted  U-shaped  tube  filled  with  gelatin  which  dips  into  both  ]t\r>. 
Kven  a  weak  current  will  cause  a  rapid  ascent  of  particles  of  the  coloring- 
matter  into  one  or  the  other  arm  of  the  U-shaped  tube. 

Salts  which  are  present  in  very  small  amount  or  which  are  sub- 
jected to  a  very  weak  current  are  not  always  dissociated,  but  are 
sometimes  merely  transported  by  the  current  in  the  ways  illustrated 
above. 

In  the  living  tissues,  as  in  experiments  upon  electrolytic  solutions 
in  glass  jars,  the  products  of  chemic  dissociation  appear  only  at  tin- 
elect  rodes.  In  the  animal  body  the  current  does  not  pass  through  a 
single  homogeneous  electrolyte  between  the  two  electrodes,  but  encoun- 
ters membranous  septa,  either  large  or  minute,  which  convert  the  path 
of  the  current  into  the  equivalent  of  a  series  of  electrolytic  cells. 

An  experiment  has  been  tried  by  Leduc.  placing  a  rabbit  in  con- 
nection with  an  anode  moistened  with  strychnin  sulphate,  and  another 
rabbit  with  a  cathode  also  wet  with  a  solution  of  strychnin  sulphate, 
the  two  rabbits  being  joined  by  strands  of  wet  gauze,  \\hen  the 
current  is  turned  on  chlorions  (chlorin  anions)  pass  from  the  tissue- 
into  tin1  solution  forming  the  anode,  and  strychnin  cations  pass  from 
the  solution  at  the  anode  into  that  rabbit,  which  accordingly  develops 
strychnin-poisoning.  The  other  rabbit  connected  with  the  cathode 
experiences  only  the  effect  of  sillphions  (SO,  anions)  from  the  cathode 
solution  of  strychnin  sulphate,  and  of  sodions  (sodium  cations)  liberated 
in  the  tissues  and  traveling  toward  the  cathode.  Using  potassium 
cyan  id  solution  for  1  he  two  electrodes,  a  similar  effect  is  noted,  but  upon 
just  t  he  opposite  rabbits.  I  Fere  t  he  toxic  ions  are  cyanogen  anions.  and 
penetrate  the  tissues  from  the  cathode  solution. 

A  similar  condition  is  found  in  t  he  animal  body,  and  the  free  products 
of  electrolysis  appear  only  at  the  electrodes,  but  there  are  complex 
chemic  processes  which  result  in  the  neutralization  ot  the  metallic  ions 
by  combination  with  tissue  elements  near  the  anode,  and  it  is  the  sann 
wav  with  acid  ions  near  the  cathode  if  that  electrode  is  moistened  with 
an  acid  or  a  salt  solution.  The  ions  derived  from  either  electrode  d" 
not  pass  through  the  body  to  the  other  electrode,  but  enter  into  com- 
bination with  certain  tissue  ions,  and  other  tissue  ions  liberated  tr-  m 
these  pass  through  the  body  toward  the  other  electrode.  The  body, 


,-.  far  as  tlir  conduction  "i  electricitv  is  concerned,  may  he  regarded 

;,„  a  mass  n|  siihni'Hi  ni  sodium  ch lurid  '^.  looo.  and  according  to  many 

,':,„.  rvers   con  .  u  [>  »nlv   hv   electfolvsis  and   not    at    all   by   the  sort    of 

passage  of  simple  electrons,  \vhieli  is  characteristic 

tals.      Thi  ran   thai    electricity   can   travel   through   the 

,-   a  rate  no!   exceeding  ."•'.'  meters  a  second,  instead  ot  at  the  rate 

,,:'    IM  1. 1  it  in   miles  a   second.     This  retardation   involves  the  con  version 

<j  ,    into  iieat  or  siinie  other  torin  oi  energy 
.     ;       jii>t     -  surelv  as  is  the  case  with  mechanic  motion 


-    heat,    and    the   remainder   acts   to   produce 
r  con  in   or  decomposition.      A  current    passed   through  an 

.-I  U    .;•  a  jai   in  '""  li'jiiids  are  separated  hy  a.  permeable 

-    •.  '::>'•'••  ,e;tl)le   UK  i  ibi'aiif  expends  a  pan   of  its  energy  in  adding 
:    re ;  ardiiii:    'he    motion    «i   particles    through    the    membrane.      A 
•  • .  •  •    ,}  i-lec;  ;-ici:  \   \-jelds  all  these  dil'ferent  forms  of  eiiergy  in  passing 
.    i:  :,   I)  idy.      I;    increases  or  reduces  all  the  phenomena 
-s  ies  accoi'ding  to  the  direction  of  the  current  and  its  mode 
\     |i     '.  niijed    application    probably    produces    chemic 
>'!>  places  ::.  the  path  between  the  electrodes,  as  well  as 
.  >-e  ci  1'itaci    wit  h  them. 

\:  .  •'._    •  H      [ire.-t     .-' -   "i'  electrolysis   are   the  destruction   of  the 

:'o    icj.-«    in    liypei't  richosis    and    of     unnatural    growths   of   various 

.  ;-.     •    :    '    •  'tion   of  various  materials,  anesthetic  and  thera- 

Coagulation  Caused  by  Electricity.--  IVoteid  matter  is  coagulated 

'•urrent<.      [experiments  by    \\".  H.  Hardy1  were  made  with 

i'o  |i    ,   -o]  it  ion  of  eir»-albunien  and  a  current   of  from   10 

1  '•"•   '.-/-.    b-ii    n!     >n]y    ]fl!1)M    milliampi-re.      When   the  solution   was 

•/'•re  carried  toward  the  anode,  with 

'   '       '         ipale.scelice     ;i!  .,|     :(     c((aLrulum     there.         The     Same 

'  •"..:•       •     •'   t  he  cat  hode  when  t  he  soli  it  ion  was  acid. 

Effect  Upon   the  Blood.   -The  experiments  of  ('.  X.  Stewart-  have 

'    '•     ffeci     i]     'led  ricity  u|»on   the  lilood.      The  ct  m- 

•h    ha-   dissolvi-il   out    the  hemoglobin  of  the 

-••::  '"  a  greater  extent   than  at  other  times. 

•    '  ains  henioirli  >hin   and 

ni    is   . -i    u'oo,]    conductor  of  electricit\') 

'_  ':   'bill    alone   is  i  lissi  (h'eil   out  , 

1  ''  'i    '  '.'  •.  lid   t  he   elect  n  ilvtes. 

'  '!  'am    more   •  •  •     >.j ....•,-•     than   can  be  <  lissi  >1  ve<  1 

'     ~ee;i!S    probable 


1'HYSIOI. <)<;ir     KFFKCTS     OF     KLK(  rl  'UK  'IT  V  '.',()} 

that  of  the  entire  blood  will  give  an  indication  of  the  fraction  which  the 
blood-cells  form  of  the  entire  blond.  This  may  be  of  value  in  r-< in- 
junction with  the  usual  test,  which  is  based  upon  the  color  of  diluted 
blood,  and  especially  when  the  apparatus  for  making  the  latter  te.it  is 
not  available. 

The  Effect  of  Electrolysis  Upon  the  Resistance  of  the  Body.— 
After  the  current  has  been  flowing  for  a  certain  time  the  resistance 
is  quite  different  from,  and  usually  much  less  than,  the  initial  resist- 
ance. This  is  doubtless  due  to  the  penetration  into  the  skin  of  ions 
trom  the  electrodes,  or  irom  the  solution  with  which  thev  are  covered, 
and  the  skin  consequently  becoming  a  better  conductor. 

This  property  of  increased  conductivity  under  the  influence  of 
electric  agents  is  similar  to  the  peculiar  property  of  the  coherer  in  the 
wireless  telegraph  apparatus,  and  it  is  quite  within  the  range  of  pos>i- 
bility  that  the  human  body  may  some  day  be  used  as  part  of  the  receiving 
instrument  in  wireless  telegraphy  as  a  laboratory  curiositv.  To  accom- 
plish this,  the  body  would  be  connected  with  the  two  poles  of  a  batterv 
with  an  apparatus  for  registering  the  slight  changes  in  the  electric 
resistance  of  the  body  which  would  occur  under  the  influence  of  the 
Hertzian  waves  received  from  the  sending  station. 

The  Polarizing  Effect  of  Electrolysis  Upon  the  Tissues. — After 
the  current  has  been  turned  off,  a  considerable  cotmterelectromotive 
force  may  be  demonstrated  by  passing  the  wires  from  the  two  electrodes 
to  a  galvanometer  instead  of  to  the  battery.  The  effect  is  of  the  same 
nature  as  in  a  storage-battery. 

Rapidly  alternating  currents-  of  small  volume,  like  those  from  the 
ordinary  faradic  coil,  do  not  produce  marked  electrolytic  effects,  and 
hence  do  not  quickly  change  the  electric  resistance  of  the  pan  to  which 
the  electrodes  are  applied.  Such  currents  are  to  be  used  when  accurate 
measurements  of  the  electric  resistance  of  the  body  are  undertaken, 
but  while  alternating  currents  of  the  character  produced  by  tin-  laradic 
coil  do  not  produce  polarization  in  the  sense  of  a  difference  in  diemic 
composition  and  in  electric  potential  at  the  two  points  of  the  body  to 
which  \}\c  electrodes  are  applied,  they  do  produce  electrolysis  and 
eventually  a  change  in  electric  conductivity  at  these  points.  Pre- 
liminary faradization  hashing  been  considered  to  lower  the  resistance 
to  the  passage  of  a  galvanic  current  subsequently  applied.  By  the 
de  \Vatteville  of  combined  iralvanic  and  faradic  current  we  produce  an 
effect  upon  the  tissues  which  permits  the  pas^i^e  ot  a  stronger  galvanic 
current  than  would  be  comfortable  or  sate  it  the  latter  were  applied 
alone.  This  may  be  due  to  the  effect  of  the  faradic  current  in  pre- 
venting polarization  of  the  tissues. 

The  lissue  changes   produced   by    the   very   rap 
charges  known  as  high-frequency  currents,  and  th 
.r-ray  and  by  different  luminous  rays,  are  de 
ters  upon  t  hose  subjects. 

It  is  probable  that  in  the  last  analy-is  :dmosl  all  the  physiologic 
effects  of  electricitv  upon  the  animal  tissues  should  be  considered  a- 
due  to  electrolysis  and  to  electric  osn  >si- .  the  last  reterrini:  to  the 
passage  of  measurable  quantities  of  a  liquid  through  an  animal  mem- 
brane. Some  of  these  different  .'flee'  now  to  be  described. 

Effects  Upon  Nerve-fibers  and  Muscles. 
to  the  bodv  causes,  according  to  Hen      -.    ;i 


:;irj  \n.mi.\i.   KI.I:<  THI<  ITY    \\i>   HONTUKN    KAYS 

i-fibers  iii  the  direction  of  the  current,  i.  c.,  from 

•;,.   ;. noile   inward   the  cathode.      This   is  coincident   with   a  depressive 

ipnii    the    nerve    t'uncimns    and    a    wave    ot    electricity 

•stein,    \\hich    may    be   due    to    a    loss   of 

IscleS.       Til''    effect    Upon    the    muscles    IS    to    cause 

ps    parah'sis.    or    in    the    case    ot    the    unstriped 
rv   tremor,   an   uncoordinated,   con- 

llut  tering    contraction    of    the    ventricles,    with    greater    than 
•  ,,i\v:    •  n's  ol   I  ides,  whicli  is  the  cause  of  death  in  man}' 

|  i  ••  muscles  may  be  made  to  contract  by  the  appli- 

•  -  directlv  to  the  muscle  or  directly  to  its  motor 

- '.;•:  nver  the  iiei'Ve  or  over  the  muscle.      A  knowledge' 

.••'in    im^i'ioii  ,•    wliich  the  motor  nerves  are  nearest   the  surtace  and 

'•  •  -  oi  i  he  muscles  (at  which  the  ,'erve  enters  the  muscle; 

-  i:ntio  ;i   elect  r<tdiagnnsis  or  therapy.      The  involuntary  muscles 

.    •        ii  •  •  -i  ine  and  oilier  part  s  may  be  caused  to  con  t  ract  or  relax  by 

•  .       nis.      Tissue  cells    in   different    parts   of   the   body  maybe 

;i  d  to  act  ivity  and  gmwt  h  by  means  of  appropriate  electrization; 

','.<•  _•    i-'  ••,  n|   the  hair  mav  be  increased.      It  acts,  therefore.  upon  the 

i     sol  t  he  nerves  as  well  as  upon  the  sensory  and  motor  fibers. 

Effects  Upon  Glands.     Currents  of  moderate  strength  increase  or 

inish  i    -    secretion   of  different    glands  through  an  effect   upon  the 

--  regulating  their  blond  suppl  v   and  those  regulating  the  functional 

••.;••.    i •:'   their   parenchymatous   cells.     The   circulation    in   different 

•    •    ;>  d\    is  increased  or  diminished  by  electrization  affecting 

t  iii      .    tsnmot  or  ner\'es  ain  1  t  he   heart . 

Effect  Upon  Special  Senses.      All  the  different  special  senses  may 

>     eject  ricit  v.       1  lie  patient  mav  see  flashes  of  light  produced 

'      '.  of  a  current    to  the  temples,  and  the  sense  of  smell, 

hearing,  and  of  tact  ile  and  thermal  percept  ion   may  be  excited. 

udentlv  of  actual  noise  or  light  or  substance  with 

:i-te  t  hat  may  be  produced  by  the  current .      For  instance, 

-''     may    be   excited   bv   electrization    of   the   outside   of 

•    •    forehead. 

'•nnt   Ihiixilit.      The  current    density  has  very  much 

-I   electrization,  and  this  becomes  reduced  as  the 

rode,  increases.      Internal  organs,  like  the  brain, 

i-rnal  application  only  a   very  widelv  diffused  cur- 

-lightl'     affected  b\    currents  of  considerable 

i    directly    to    the    substance   of   the   brain 

v.'ith   very  much   weaker  currents.      It    is 

Kibrillary    t  reinor   is  excited   b\"   a 

[lefes     from     electrodes    ap])lied    directly 

t'rent   oi   twentv  milliamperes  will 
hp    ed   i  hroiigh  elect  ri  ides  placed  on 

1  'lie  elect  rode  from  a  galvanic 
• '  neck  and  t  he  oi  her  nver  1  he 
'  .  are  pr<  >duced  \vlien  the 
oi  i  he  c'|i  isii  re  ot  the  current  is 

-  '  "•  mi    the   bra  in    t  o  ward    t  he 

-  most    pronounced  when   the 


PHYSIOLOGIC     KFFKCTS    OF     KLKCTRK  ITY  -5UO 

current   is  from  the  eye  toward  the  brain,   that    is,  when   the  anode  is 
placed  upon  the  eye. 

An  electrode-  being  applied  to  each  side  of  the  eyeball  and  a  con- 
tinuous current  flowing,  a  sensation  of  light  and  color  will  be  produced. 
The  half  of  the  field  of  vision  cont  rolled  bv  the  part  of  t  he  ret  in  a  nearest 
the  anode  appears  greenish,  while  that  perceived  by  the  part  of  tin; 
retina  near  the  cathode  appears  brighter  and  bluish.  Different  persons 
see  various  forms  and  colors  under  the  influence  of  electric  currents 
applied  to  the  eye  in  these  or  similar  ways. 

Flashes  of  light  are  seen  when  an  electrode  is  applied  to  the  fore- 
head and  another  to  the  epigastrium. 

Aii(lit<>rif  Ejl'cctx  of  Elcc.tricitii.  -One  electrode  being  applied  near 
the  ear  and  the  other  to  some  indifferent  point,  sensations  of  sound  an; 
produced  by  the  galvanic  current.  The  effect  of  the  cathodal  closure 
is  the  strongest,  but  a  sound  is  also  noted  at  the  opening  of  a  stronger 
current  when  the  anode  is  applied  to  the  ear. 

Influence  <>f  tin1  Position  <>j  lh<  El«-i/'<x/i .-.  The  position  of  the 
electrodes  has  a  great  deal  to  do  with  determining  the  density  of  the 
current  passing  through  different  organs,  and  hence  regulates  the 
physiologic  effect  of  the  current.  Electrodes  held  in  both  hands  send 
a  much  smaller  proportion  of  the  current  through  the  brain  than  is  the 
case  when  one  electrode  is  at  the  top  of  the  head  and  the  other  at  the 
feet.  Electrodes  placed  at  both  sides  of  the  head  are  thought  by  some 
observers  to  send  a  sufficient  current  through  the  brain  to  produce  a 
therapeutic1  effect,  while  others  believe  that  the  current  is  too  widely 
diffused  and  that  much  of  it  follows  the  homogeneous  conducting  layer 
afforded  by  the  seal]),  and  passes  around  the  skull  and  not  through  it. 
Without  trying  to  decide  this  question  it  may  be  stated  that  cerebral 
conditions  are  apt  to  be  much  more  influenced  through  the  vasomotor 
and  other  effects  of  electric  currents  upon  the  cranial,  spinal  accessory, 
and  sympathetic  nerves  than  by  the  direct  effect  ot  the  portion  ot  the 
current  which  can  be  sent  through  t  he  brain  itself.  \\  hen  t  he  electrodes 
are  placed  very  near  each  other  upon  the  surface  of  the  body,  the  resist- 
ance at  the  points  of  entry  and  exit  of  the  current  greatly  exceeds 
that  of  the  portion  of  the  body  between  these  points,  and  the  current, 
almost  all  follows  a  short  straight  line  with  scarcely  any  diffusion 
Placed  close  together,  even  over  the  motor  point  of  a  muscle,  a  fairly 
strong  current  may  not  excite  a  contraction. 

A  dailv  example  of  this  strictly  local  action  of  the  current 
the  electrodes  are  applied  close  together  is  afforded  by  the 
trician  when  testing  a  1  H)-voIt  electric-light  socket.  To  see  wh 
there  is  current  present,  he  moistens  his  finirer  and  puts  it  inside  the 
socket,  thus  making  contact  with  the  positive  and  negative  terminals. 
If  the  current  is  there,  he  gets  a  pretty  sharp  sensation  in  the  finirer, 
but  this  is  not  very  disagreeable  and  not  dangerous.  It  is  quite  a 
different  matter  from  the  experiment  tried  by  the  author,  ot  holding 
a  metal  object  in  each  hand  and  then  placing  these  objects  in  contact 
with  the  terminals  of  the  1  10-volt  direct  circuit.  As  the  contact  was 
made,  a  sense  of  severe  shock  was  experienced,  accompanied  by  a 
violent  involuntarv  muscular  contraction  which  jerked  the  arms  down- 
ward and  backward,  and  caused  the  metal  objects  to  be  thrown  back 
across  the  room  and  to  make  a  dent  in  the  woodwork  there.  It  i>  an 
experiment  which  he  would  not  advise  any  one  to  repeat,  but  i;  1:01 -s 


:;nl  MKDICAL     KI.K<TKHITY     AND     R«).\T(iEX     HAYS 

sho\\  ':.:••  accidental  contact  with  both  the  bare  conductors  carry- 
in^  the  1  in-voh  direct  cunvni  will  nut  necessarily  produce  serious 
iv-ults,  [he  lad  that  ::u  usually  moistens  his  finder  before 

tes'ini:  t'ni1  i-u rn 'in  in i lie;  te.-  t  hai  I  he  resistance  at  t  he  point  of  accidental 
..;:,    conductors   would   usually   l>e  so  great    that   no  very 
>•  ;•  ii .1:  current  would  pass  t  h  roil  ill  i  i  he  body.     In  t  he  author's  experiment 
'inns  were  different :   the  electrodes  were  constituted  by  large 
.  •  •       •  .  e  cio.-rd  hand,  the  large  surface  and  perfect 

,•  .;.-  |  esislaiice   to  a    lllin  illllllll. 

I"  inchini:  »:n    bare    I  Hi-volt    direct  current  conductor  with  the  dry 

:.•  _'.  •     t^ive.-    i)  •    appreciable    sensation    under  ordinary   circumstances. 

>\\  ever,  '  he  pi  rsoii  is  .-t  aiiding  on  a  floor  which  is  a  goi  id  conductor. 

i:  ••..  inr  e\;  '    pie.  M  shock  may  be  received  of  the  same  nature  as  that 

-    .        nil  i--'.-  experiment,   but    of    much  less  severity.      This  is  due 

fact   thai    ;'    is  practically  impossible  to  ,'isulate  a  dynamo  from 

•  •    •     ;•',.  an  ;  c  'iisei jiieiit ly  a  circuit   is  formed  when  a  complete  con- 

•  ..••_•:••          [ii'ovided  from  either  terminal  to  the  earth.       A  person 

.  loden    tioor   with    perhaps   a   woolen    carpet    is   pretty 
••••I  frmi)  the  earth  for  currents  of  this  tension. 
\   ••    ''.-•   p  iwerfu]  curi'ent   may  be  aj>]ilied  b\"  means  ot  needle  elec- 

-  i-l  >r-e  ti.irether  for  the  destruction  of  tumors  of  the  breast  than 

-,•</    applied   i:'  the  electrodes  were  placed  at   a  distance  and 
•     -  '.    •  -    that    the   current    would   traverse   vital   organs.      Still. 
-••  -'.^  cunvi  ts  are  employed  by  some  opei'atoj-s  in  cataphoresis. 
-  the  patient   lie  upon  a  lai'iTe  kaolin  or  clay  cathode  placed 
:    •;.-•  -acral  and  iduti'al  reu'ion.  while  the  positive  wire  terminates 

•  .'    !•!•:    oi    >liar]i   [mints  of  xiuc  amalgamated   by   mei'cui-y.     The 
!•-  tit   :-  ly  nirned  on,  and  a  maximum  of  •_'( n i  or  .'-inn  or  more 

-     •'   the  dil'i'Cl    current     is  allowed   to  flow  even   if  the  anode 
':.'    .-'     into    a    'j;rowlh    on    the    face.      The    heart's    action    is 
(>•!'.:  .  is  not  materially  affected.      An  alternating  cur- 

'.'    with    sudden    variations    in    streiii:th    would 
-   :vs;;lts   if  iippliei  1    in   t  his   way. 

'    '•'   with  both  terminals  of  a  hiirh-tension  circuit  at 
'•.•:    on    the  surface  of  the  lioil\-   may   lie  followed   bv 
a-  contact    with  one  terminal  alone,  with  coti- 
i;    '  '  the  ground,  or  with  both  terminals  at  dis- 

er>al   rule  that   a  high-tension  current   is 
el'-c  'lose  to<fether,  as  described  abo\'e. 

Influence  of  Voltage  and  Amperage.     The  voltage  or  tension  of 

•  iver  t  he  si  ren^t  h  or  amperage 
I  •  uly  tVom  one  electrode  to  the 
•  fieri    in  i  jet  i-rmin  inn  the  effect 
lerived    from   a   source  of 
.;  ieres  ei  jual  to  t  he 
11  '.    .      S.  iiirces  of  very  high 

'    MI-  mad  i  inc.  do  not 

':'  ••:'      '  •  .  e    the    Voltage 

\    ha!  -:  '     '  .        etal   ball   at   a 


1'HYSIOLOdir     KFFF.CTS     OF     KLKCTKK  ITY  OUO 

the  latter  will  probably  not  damage  anything  it  strikes.  The  high 
potential  is  capable  of  sending  great  amperage  through  tin-  body,  but 
does  so  only  when  the  necessary  quantity  is  supplied.  This  is  the  case 
with  currents  immediately  from  large  dynamos,  or  as  modified  by 
step-up  transformers.  It  is  really  the  combination  of  tension  ami 
quantity — that  is,  energy  or  the  number  of  watts — that  largely  deter- 
mines the  effect  upon  the  tissues. 

Effect  of  Static  Electricity.— The  static  spark  produces  a  different 
effect  according  to  whether  it  is  applied  singly  or  as  a  continuous  si  ream 
of  sparks  upon  the  same  spot.  In  the  first  manner  it  produces  an 
effect  which  is  due  to  molecular  vibrations  and  not  due  to  immediate 
visible  changes  in  the  tissues.  The  effect  is  one  of  stimulation  of  1 1n- 
activity of  the  cells  of  the  part  to  which  it  is  applied,  and  of  the  central 
nervous  system  and  of  the  vasomotor  nerves.  Therapeutically,  isolated 
static  sparks  are  beneficial  where  there  are  lowered  arterial  tension  and 
nervous  debility,  and  in  painful  conditions  dependent  upon  them.  It 
is  not  generally  beneficial  in  conditions  of  irritat  ion  and  painful  affect  ions 
dependent  upon  them.  High-tension  electricity  appears  to  be  prefer- 
able for  debility  and  depression,  while  low-tension  electricity  is  prefer- 
able for  irritative-  conditions. 

A  stream  of  static  sparks  applied  to  one  spot  will  prove  very  painful 
at  first,  but  later  produce  a  benumbing  effect.  There  is  redness, 
followed  by  blanching  and  swelling  of  the  skin.  If  the  application  is 
verv  prolonged  and  severe,  it  produces  superficial  destruction  of  tin- 
skin . 

Static  sparks  cause  a  muscular  contraction  which  is  quite  valuable 
diagnostically,  especially  when  they  are  applied  singly  and  their  tension 
and  quantity  are  accurately  gauged,  as  is  the  case  with  condenser 
discharges.  The  latter,  however,  are  more  often  employed  for  diagnosis 
or  treatment  with  a  much  smaller  voltage  than  characterizes  the  output 
of  the  static  electric  machines. 

Static  insulation  produces  about  the  same  effects  as  the  static 
spark,  without  any  of  the  disagreeable  effects  of  the  latter.  It  is  not 


Pos- 


—  Neg  . 


Floor 
ground 
WOfer  or 
yas  /">*• 


quite  so  strong  a  stimulant,  but    is  pivi'<  rable  for  a   great   many  cases. 
The  static  breeze  produces  a  l<>cal  and  gem  ral  tissue  stimulation  wit  hoi; 
any  uncomfortable  symptoms.      Morton's  wave  current   and  the  statii 
induced  currents  produce  similar  effect-,  but   with  more  sense  ni 
and  muscular  contraction.     All  verv  high-tension  discharges  with  very 


MI  PI'    \l.    KLKI  TKIdTY    AND    RONTGEN    RAYS 


derrd    to    produce   effects   by    means   of 
rather    than    by    transportation    of    ions 
ihrouiili    the    tissues    and    liberation 
of  chemic   products   at    or    near  the 
points  of  contact. 

Effect   of    High-frequency   Cur- 
rents.    The     different     applications 
grouped  under  the  name  of  high-fre- 
quency currents  do  not  produce  mus- 
cular    contraction      or     electrolytic 
effects    corresponding  to    the   quan- 
tity of  electricity  passing  to  the  body, 
and  apparently  passing    through    it. 
This    is   because    the    transportation 
of  ions    through    the   semipermeablo 
membrane     formed    by    the    human 
body  cannot  keep  such  rapid  rhythm 
;-  •  ii  —  currents.    The  conducting  wires  transmit  the  to-aiid-tro  currents 
..    metallic    conduction,  >imple  transmission   of  electrons  without   the 
van  -p1  'nation  of  inns  (  part  ides  charged  negat  ively  by  an  extra  number 
•r  pins,  or  positively  by  deprivation  of  electrons),  and  subject  only 
o  •  in1  nrdinarv  ohmic  resistance  and  to  impedance  due  to  induction.    The 
in  its  relation  to  these  excessively  rapid  oscillations  may  be 
•onsidi-n   ;   as  a  capacity  which  is  alternately  charged  and  discharged 
;it!    'Ui  much  current  passing  through  it  .      It  may  be  compared  to  a  bal- 
it  li  a  large  opening,  through  which  air  is  blown  in  and  the  balloon 
•d  and  then   ;illo\\eii  to  collapse,  an  opening  at  some  other  point 
e  im:  so  small  that  it  dues  not  prevent  1  he  balloon  from  being  blown  up, 
during  its  collapse  allows  very  in  tie  of  the  air  to  escape  in  that 
•  '    •  .      To  make  the  analogy  complete,  we  should   have  two  large 
'     ippositr  sides  of  the  balloon,  alternately  one  and  then  the 
•  '•:'.!!  closed  (hiring  I  he  rush  of  air  into  and  out   of  the  balloon 
•'  •-•  :    iar^e  opening.     The  fact    that    the   high-frequency 
d  >••-  Hot    in    greai    part    ]>ass  through  the  body   lias  lead  to  the 
'    '   .--  found,  like  static  electricity,  chiefly  on  the  surface 
I  ;ii-  does  imt  appear  tn  be  the  case,  ami  there  is  not  the 
<    '.  '•.  static  electricity,  win-re  the  voltage  is  much 
••   '••'>..-.'  'ii   oi    the  charge   is   much   greater-.      It    'has  been 
frequency   currents   have  an  effect    upon   deep 

Pathologic    Effects  Upon  Workers  in  Electric  Power-houses.— 
ises    in    which    the   natural   power   from   water 
-  ::•!    Falls.   i>  converted   into  electricitv.   and  other 
•'ric  furreni    is  transformed  from  the  very 
i]    'Jn.nno   volts  or   more  to   the   utilization 
abnormal  coi  id  it  i<  ins  for  t  heir  work- 

.1     percept  ible    effect     U])oll    any 

rroun 
"     • 


tese     <rreat     dynamos    and 
upon    the  i  irganistu.      \\  "e  are 

i  such  en\'ironmeiiis  upon  a 
d  b\  the  x'isible  am!  invisible 

i  ri^es  :  m  iduce  the  ult  raviolet 
\  arious  factors  are  njn-rative, 


PHYSIOLOGIC     EKKKCTS     OK     KLL<  TKK  Tl  Y  307 

though  they  j)roduc(;  no  perceptible  effect  upon  a  person  who  visits  such 
a  power-house  for  only  a  few  minutes.  Millener,  of  Buffalo,  X.  V.,1  has 
observed  bad  effects  in  --  cases  among  t  he  workers,  t  he  sympl  oms  being 
pallor,  loss  of  appetite,  abdominal  pains,  indigestion,  and  constipation. 
In  some  cases  it  was  noted  that  if  the  man  ate  his  lunch  at  the  power- 
house or  returned  to  the  power-house  directly  after  going  out  to  lunch, 
indigestion  followed,  while  if  the  lunch  was  eaten  at  home  and  the 
man  did  not  return  to  the  power-house  for  a  considerable  time,  no  dis- 
tress was  experienced. 

The  power-houses  are  perfectly  ventilated  and  drained  and  warm 
and  clean,  and  there  is  sufficient  exercise  to  keep  the  men  in  good 
condition  physically,  so  that  the  conclusion  is  that  the  svmptoms  are 
due  to  electricity.  Alternating  currents  passing  through  the  coils  of 
wire  in  the  fields  and  armatures  of  these  enormous  machines  produce 
expanding  and  contracting  lines  of  force  which  we  should  expect  to  be 
more  effective  in  influencing  the  human  organism  than  a  continuous 
current.  Then1  are  no  recorded  observations  to  decide  this  point, 
but  Millener  adduces  the  fact  that  milk  rapidly  sours  in  a  power-house 
where  high-voltage  alternating  currents  are  present.  He  also  states 
that  in  butter  factories  machines  run  by  an  alternating  current  motor 
cannot  be  used  because  the  cream  sours,  while  no  such  objection  is 
found  to  the  tise  of  a  direct  current  motor.  The  souring  of  milk  by 
lightning  is  another  example  of  the  effect  of  electricity  upon  organic 
substances. 

The  only  protection  against  these  deleterious  effects  at  present 
known  is  to  take  frequent  vacations  from  the  work. 

The  Effect  of  Working  in  the  Room  with  A'-Ray  Coils  and 
High-frequency  Current  Apparatus.  The  most  powerful  apparatus 
of  this  kind  takes  only  a  very  small  fraction  of  the  output  of  a  dynamo, 
and  the  influence  pervading  the  room  is  correspondingly  weaker.  of 
the  many  patients  and  physicians  who  have  visited  the  author's  office, 
not  one  has  ever  complained  that  his  watch  had  been  magnetized,  and 
the  author's  own  watch  keeps  perfectly  correct  time.  Then,  again, 
the  author's  experience  of  being  constantly  in  the  treatment  room,  with 
no  vacation  of  more  than  five  days  at  a  time  in  seven  years,  and  never 
missing  a  day's  work  on  account  ot  personal  illness,  indicates  an  absence 
of  deleterious  effect  from  long  exposure  to  the  influence  of  apparatus 
of  this  capacity.  This,  however,  does  not  mean  that  one  can  remain 
exposed  to  the  .r-ray  day  after  day  with  impunity.  One  must  cer- 
tainly be  shielded  from  the  rays  from  an  r-ray  tube,  either  by  some 
shield  of  lead  or  other  opaque  material,  or  by  always  remaining  in  an 
adjoining  room.  Practically,  nothing  is  impervious  to  electromagnetic 
induction  or  to  the  so-called  lines  of  force  ijenerated  1>\-  induction  coils, 
etc.,  and  it  is  fortunate  that  the  influence  from  those  ot  a  suitable 
capacity  for  .r-rav  and  electrotherapy  seems  to  be  beneficial  rather 
than  harmful.  However,  lotm  exposure  to  the  ./'-ray  itselt  is  very 
harmful,  as  is  stated  more  fully  elsewhere  in  this  book. 

The  effect  of  high-frequency  currents  upon  the  tissues  is  very 
important,  and  is  found  in  a  separate  chapter  upon  that  subject. 

Effects  of  Condenser  Discharges.  The  most  valuable  observa- 
tions are  t  host1  which  determine  t  he  single  discharge  necessary  to  produce 
a  muscular  contraction,  and  then  the  frequency  with  which  thai  discharge 
1  American  Medicine,  A  iiru>t,  I'.'Of,.  p.  ~2 '•>.'>. 


Ml. Pit    \1.     Kl.Ki    IKlt   in       \\1>     HI  >.\T(,K.N    KAYS 

i    usi  l)r  iv] >t -a it-.!  in  order  to  produce  tetanus.     These  vary  in  different 
; :  iiscli  -  •  ml   ii:  i ; : i'l e  n -n  I   an  imals. 

A   Miiiabie   arrangement    of  apparatus   is  shown   in    Fig.  217. '      The 

•  1 1   ••  :  •.[•  -  I .  ainl   I    arc  apph'i-d  in  i  lie  annual  experimented  upon.      One 

•  i-ti  •  i  v.  ;•  •:  mie  an    at  u iv  oi  a  condenser  M.  having  a  capacity  of 

microfarad.       I'lie  other  electrode  is  connected  with  a  pivotal  point, 

i  '.  n:'  a  tine  pi:  •  ire,  which  carries  a  small  iron  hammer  at  one  side 

•  >  >sin<:  >pring  al  t  he  ot  her  side  of  the  pivot.      \\  hen  t  he  ha  miner 

'•d  lr.    tiii    action  of  an  electromagnet,  the  point   X  makes  an 

in  i. •!•  cup  of  mercury,  and  through  that  with  a  source 

t '.  iif  \  [»oteii!  ial.      I'he  animal  and  t  he  condenser  are  t  hen  charged 

;  i  tiii  '[  potential,  and  the  quantity  of  electricity  may  be  calcii- 

';•<.;    ::   >:i     I 'he   voltage   and    the   tixed  capacity   of  the  condenser.      The 

<     -'v  df  the  animal  is  tixed  also,  and  is  only  a  small  fraction  of  the 

>!   the  condenser.      It   dues  not   affect    the  calculation.      \Vhen 

ii  :.•-:  ii  '  ceases  to  act,  t  he  spring  breaks  the  contact  at  X  and 


1    •  ."    merciirv   cup   at    L,  and    t  hence   to   tin 


discharged  through   the  animal  heiween 


i-niial  consists  of  a  battery  1'",  the  two 

the  extremities  of  a  resistance  wire, 

:•  • : .       There    is   a    .-liding   cont  act  ,    ( '. 

1 1    :   to  the  animal  and  the 

I  he    contact    is    at    A,    to    1  he    full 

-•••pa rale  battery    P.   the 

1  i.  which  1 1  ips  into  a  mercury 

'    e  mercury  when  at   rest . 

'. .   i  he  durat  i""   of  each 

•   is  flowing. 

:'    adj  ;  -;  ::;  ile    length,  and 
;i,d'T    1     e     influence    of     its    own 


I'll  VSIol.  ()(,!(       I.I- FKCT.S    OF    KLK<  TKK  Ti  V 


300 


r;    (',t    iliiYrrcnt    ground    connections:    X. 


battery,    P,   and   its  ovni    electromagnet.     There    is  a   separate   electric 
signal   which   may   be  brought    into  this  circuit    bv   turning  the  ,-,witch 
1  rom  m  to  p.  instead  < >l    fr< mi  m 
to  n.      The  signal  acts  synchron- 
ously wit  h  t  he  mot  ions  of  t  he  vi- 
brating  interrupter  and  enables 
one  to  count  the  latter. 

A  simpler  arrangement  is  used  'e 
when  single  or  isolated  condensi  r 
discharges  are  applied  in  elect  ro- 
diagnosis  or  electrotherapy.  ( >ne 
armature  of  t  he  condenser  ( '  (  Fig. 
_'l  s  is  grounded ;  t  he  ot  her  arm- 
ature is  connected  with  the 

pivotal  point  of  a  Morse  telegraphic  key.  In  the  normal  position  a 
spring  causes  the  Morse  key  to  make  contact  with  a  wire  leading  to 
one  pole  of  a  battery,  the  other  pole  of  which  is  grounded,  and  in  this 
position  t  he  condenser  quickly  become-  charged  to  its  full  capacity  at 
the  potential  of  the  battery.  Depressing  the  Morse  key  breaks  the 
connection  with  the  battery  and  makes  a  connection  with  a  wire  lead- 
ing to  the  nerve  or  muscle,  from  which  another  wire  leads  to  the 
ground.  The  condenser  discharges  through  the  animal  and  the  ground, 
as  they  form  a  complete  circuit  between  its  two  armatures.  A  metro- 
nome dipping  a  wire  into  a  cup  of  mercury  may  be  substituted  for  the 
Morse  key  when  discharges  are  to  be  applied  at  regular  intervals. 

Condensers  for  diagnosis  or  treatment  have  a  capacity  vaiying  from 
-i,1, ,,  to  2  microfarads. 

The  condensers  used  in  the  arrangement  described  above  are  of 
large1  capacity,  having  1000  or  several  thousand  square1  ine-he's  of  con- 
den-ing  surface,  and  are  charged  to  a  potential  of  '•}()  to  100  or  '200  volts. 

Effects  of  Leyden-jar  Discharges, —Condenser  Discharges  <it 
Hi'lh  Potential  front  thf  Sltitic  Marln'itf.  These  are  1  he  currents  intro- 


(luced   by   Morton,   and   in   the  usual   >       ho 

armatures   of  the  jars  are  connected  "         t 

machine  (  Fig.  'JlO  .      The  oute 

that    of  tlu1  other  jar  is  connected   \\':'  i1   electi'odr   a]i])lii 

the  patient.     The])atient  is  i  The  (lischarging  ro( 

static  machine  are  close  together.     T:  •    'wo  inner  armatures  di>c!  ;  ixre 


:;in  Mi:i>i'  M.   KLK<TKI<ITY   AM;   ROXTGEN   KAYS 

aero--   the   -park-Liap   :ii    regular   intervals,   and   simultaneously  a   con- 

deiiMT    di-charne    occur-    between    the    outer    armatures    through    the 

•anii.      In  this  case  there  may  b<' high-frequency 

•<;,•.-      ;,  ,•     |  he    chief    noticeable    effect     L-    from    the    discharge    of 

the   1. !••.•;•  '    a   comparatively  low  rate  of  frequency,  as  indicated 

icce--ive  -park-,  and  consists  in  muscular  contractions  and  a 

sen-,  h  i-  disagreeable  if  the  spark-gap  is  long,  and  hence 

the  [•  >;id<  n-er  i  li-cha:  tie-  arc  severe. 

1        ,  ;;,  ,'ts    'f  condenser  din-barges  of  different  quantity,  potential, 

naturallv  variable.     The  factor  of  quantity  is  found 

lr.  ini:  the  capacity  of  the  condenser  by  the  voltage  to 

i   j:    is  c!  ai'ircd,  <J      <    \  .      The  energv   required  to  charge  the  con- 

:••.•    matter,  however.      It   is  equal  to  jCT1',  and  this  is 

.  i   •        effective  energv  that    is  liberated  when  the  condenser  is  dis- 

cha-     : 

The    Stimulation   of    Muscular   Contraction   by   a   Single   Con- 
denser   Discharge.     The   object    of   numerous   experiments    has   been 
elation  between  the  voltage  and  the  capacity  required 
•  .   :> •  •  '.  ire  contraction.      A  condenser  of  a  fixed  capacity  is  used,  and 
ide-    applied    to    the   exposed    nerve    are   connected,    as   shown    in 
l-'itr.  _'lv     The  cntidenser   i.-  at    first  charged   and   discharged  at   a  very 

•  •••'. •;::•.   which   i-  gradually  increased  until   a  minimal   muscular 
•'.  in    i-    produced.       The    capacitv    of    the    condenser    and    the 

vo.  ••,•_;,•   are    recorded,  and  then  the   same  experiment    is   tried  \\ith  a 
,  tf civil!    known  capacity,  either    greater    or    le.-s    than 

•  l  he    first.      |i     is    found    that    the    voltage    to    which    diffei'ent 
c  ''.  ;••'!-*•:-    n.M-i  be  charged  m   oi'dcr   to   produce  equal    mu.-cular  con- 

•*ion-    does    not     varv  inversely  as  their    capacity,  as  would   be  the 

'    '   .e   -ai  ic   quantity  of  electricity   were  discharged    in   each  case. 

!•"  coiidhion-   required  correspond  more  nearly  to  those  in  which  the 

:  ur     i-  the  same,  so  that    in    each  case   \('\"-  amounts  to  the 

'.<•-.      The  required  voltage,  therefore,  varies  approxi- 

'   ie  square   root    of  the  capacity.      If  a   condenser 

,:;-'  be  charged  to  a  potential  of  'JO  volts  in  order 

in.    the   -nine  effect    would   be  produced 

tour  times  that   capacitv.  charged   to  a   potential  of 

;>     •    condenser  ot  one-fourth  that   capacitv,  charged 

These  proportions  hold  good   within 

b  ;i    :  nl    '  u   extreme  ca-cs.      Thus,  a  single  discharge 

ible  conilen-er  fail-  to  u;ivo  muscular  contractions 

only    one    volt.      I-!ven    in    this   case. 

'     condense!'    discharges    will    produce 

doe-    not    appear   to  be  due  to   a    lessened 

1  ' . '.  does  not  re-nlt  ;'n  mi  successive 

:  Uce      hardly      ailV      elect  1'olyt  ic 

at  ion  being  due  to  an  overlap- 

f  ion  ,  \\-it  h  a  ci  mse(|uent  cumula- 

I  I  e    fact    t  hat    the  height  of 

1  ••.   i  he  ga  Ivan  ic  cu  rrent   is  con- 

' :  inul  i  are  a  p|  >\  led  in  rapid 

1  •'•'  •  ; '    '    e  bo  .  however,  be  modified 

•MI  rent  fi  »i'  -i  une  t  ime.  and  t  hen 

.  i  i  pn  iduce  a  great  er  efTect 


PHYSIOLOGIC   KFFKCTS  OF  KF^KCTUICITV  .'ill 

The  physiologic  effect  of  a  single  condenser  discharge  is  clearlv 
modified  by  the  useful  duration  of  the  discharge,  but  there  is  a  question 
as  to  this  brin«;  called  the  law  of  stimulation  by  condenser  discharges, 
us  surest  ed  by  Clu/et.1  and  the  Lapicques  have  made  a  series  of 
experiments  to  determine  this  point  and  with  negative  results.  - 

The  duration  of  the  discharge,  of  a  condenser  is,  however,  considered 
by  Lewis  Jonrs:i  as  affording  the  best  numerical  expression  for  the  con- 
tractility of  a  muscle  to  this  form  of  stimulation.  (See  also  page  />()(). 

riuzet,  Dubois,  Zanietowski,  Iloorweg,  Cybulski,  Weiss,  and  I'revost 
and  Hat  tell  i  have-  made  accurate  experiments  wit  h  cundenser  disci  utrges. 
This  must  be  regarded  as  a  new  and  valuable  addition  to  the  means  of 
elect  rodiagnosis  and  electrotherapy. 

The  effect  of  a  condenser  discharge  may  be  modified  by  introducing 
an  additional  resistance  or  inductance  or  capacity  in  the  circuit,  the 
effect  being  to  reduce  not  so  much  the  intensitv,  as  the,  duration  of 
the  discharge.  The  length  of  the  wave  of  stimulation  makes  the  same 
difference  with  condenser  discharges  as  it  does  with  the  make  and  break 
of  a  continuous  current. 

Muscular  Contraction  from  Rapidly  Repeated  Condenser 
Discharges.  -Applying  two  metallic  electrodes  to  the  sciatic  nerve 
of  a  frog,  tetanus  is  produced  by  discharges  of  the  same  condenser. 
charged  to  different  voltages  and  at  a  different  rate  of  speed. 

Frequency  per  second.  \'<>ltn</< 

14 
1.") 
I'.t 
21 


40 

From  this  experiment  it  will  be  seen  that  the  voltage  required  to  produce 
tetanic  contraction  is  very  much  less  for  rapidly  than  for  slowly  repeated 
discharges. 

Discharges  at  the  rate  of  from  2")  to  .'•>(>  a  second  produce  the  most 
powerful  contraction.  Such  condenser  discharges  produce  effects  which 
are  very  similar  to  those  of  the  faradic  current,  but  they  can  be  much 
more  accurately  measured  and  applied.  1  he  same  thing  is  true  ot 
single  condenser  discharges  as  compared  with  isolated  induction  shocks. 

Muscular  Contractions  from  Condensers  in  Parallel  with  Galvanic 
Currents.—  The  length  of  time  it  takes  to  charge  or  discharge  a  condenser 
at  voltages  ordinarily  u<ed  in  galvanic  applications  is  employed  by 
Lapicque  to  prevent  the  unnaturally  jerky  character  ot  the  muscular 
contractions  ordinarily  produced  at  the  make  and  break.  For  this 
purpose  \Y.  .1.  Turrell1  uses  15  condensers,  each  ot  -  microfarads  capacity 
and  so  arranged  that  any  number  ol  them  may  be  connected  in  shunt 
or  parallel  to  the  pat  ient  .  The  total  capacity  ot  t  he  condensers  ivirulatr- 
thr  time  required  for  the  cm-rent  through  the  patient  to  attain  its  full 
strength  at  the  make,  and  the  greater  this  time,  the  less  abrupt  is  tin- 

1  Comptps  rcndu<  <!<•  l;i  Socii'tr  tic  Hi 
-  Uiid..  .July  t  .  I'.io.'i.  p.  (>:•;. 
3  Archives  of  the  Roentgen  Hay,  Ma 
1   \nicr    .lour    Kle('trotherap<'Utie-   aiu 
p.  207. 


:',!_'  Mi-iDit  AI.   n.i:' TI;H  rn    AND  KONTGEN  HAYS 

mii-ci;'.;.  ;•    '( 'in  raci  ion.     There   r-  a   similar  ettect    at    the   break.     The 
•  .  _  ,     •  irn  11!   -'  hould  he  by  means  of  a  liquid  or  a 

the   ordinary   wire   coil    rheostat.      Tluv 
[•c    ii'ivi-s   an    induced   current    with    its   well- 
ici    al  ini]  ii   muscular  <•<  mi  ract  i<  »ns. 

1  .    Hen.a  u-e-  the  condenser  discharge  ajiparatus  of 

1    -he-  and  vulcanite  discs  wit  h  copper  sectors. 

ivi-    1    •••  [eii-er  discharges  a   second.    1    behm  tienerally 

11  .    KK).  1'Ui    may  he  changed  to  200.      'Die 
.  n  d  at    loll  volts  should  he  noted.      If  there  is 
ii  _' .10  covery  may  -till  take  place.      But  if  response 

a  r- after  1 2  discharges  i  1  per  second)  the  ease 
•  •  ••  n  c<  iver  wil  IK  >ut  operat  ion. 

ve  lieen  oh-erved  hv   Hollet  to  produce  the 
1  e  hi. mil  as  ot  he!1  form-  of  elect  rich y.     Tie  has  found 
LIVS  may  clarify  the  hlood.     The  hlood  would 
1    nf  a    traii-parent    red    li()uid   in   which   float    colorless   and 
o-e  h'-nioulohin  has  hcen  di>>olved  out  by  the  blood 
Ti  >  In    fiiund  takes  place  even  when  the  lieatiiiti'  effect  of  the 
-  eliminated.     I'nder  other  cireumstaneos,  as  where 
.•"I  i-  -ubjertcd  to  a  coiiden-er  discharge,  the  amount 
'    _     ..  :    ted   i-   aiiijily   -uflicient    to  account    for  the  clarifying  of 
Max  (    '.  UK  !     colliders  the  thei'inal  (-lenient  as  the  chief  one 

•  on,    it'    it    affected    any    considerable    portion    of    the 

the  circulation,  would  be  of  vital  importance.     The  property 

_i'ii  ni   loose  combination  from  the  hum's  to  the  ii»ues, 

,   from   the   tis.-ues  to  the  lun,u-.  is  practically  lo>t  by 

.  •:    :'    i-  di.— -lived  out   of  the  red  blood-cells.      It  will 

-    the    principal    reason    why    salt    M>lr,ti»n    is 

' "  '   .'    vi  in.-  afti'i1  hemorrha.ue  instead  of  plain  water. 

the   hemoglobin   and  defeat    the  very  object    nt 

-    '    '•  oxygen-carrying  ]»ower  of  the  blood. 

.     .   oWeVe)1.     It      IS     ll'it      to     be     supposed     that 

ducetl   iijtoij    the  blood   in   the  li\'ing  body   to 
.    •'.>.;.    !  "  affect  any  \'it  al  funct  ii  m. 
DuBois-Reymond's  Four  Laws  of  Electric  Stimulation. —  1.  The 

>  'tie  -'reiiii'tii  MI   the  current  or  ampej'age  which 
i".  nerve,    ir  oi  her  01  ^an. 

ches    I  he    oi'^an    to   be  St  illlU- 
.  i-U  I'reiil   and  part  ly  upi  in  1  he 

II   direct  ions   irreat  ly   reduce.- 

lie     of     I  lie     elect  I'odeS     is 

•     e  lat  tel1  is  quite  near 

if  the  1 1  iff  erei  it   muscles 


PHYSIOLOfilC    KFKKCTS    OF    KLKCTHK'ITY  ?>}'.>> 

'['he.  ])<>lar  effect  is  evidenced  by  the  swelling  from  muscular 
contraction  which  takes  place  in  a  striated  muscle  at  the  cathode  when. 
the  current  begins,  and  at  the  anode  when  the  current  is  turned  off. 

The  polar  effect  upon  unstriuted  muscle  is  evidenced  bv  a  relaxation 
of  their  normal  tonic  contraction  at  the  anode  during  'he  passage  of 
the  current,  and  at  the  cathode  when  the  current  is  turned  off. 

The  polar  effect  upon  a  nerve  is  a  \vave  of  stimulation  starting  from 
the  cathode  when  the  current  is  turned  on  or  its  strength  is  increased, 
and  starting  from  the  anode  whenever  the  current  is  turned  off  or  its 
st  rengt  h  is  diminished. 

4.  The  cathodal  closure  effect  is  >trontrer  than  the  anodal  closure 
effect. 

DuBois-Reymond's  Law   of   Electric    Stimulation   by  Variable 

Currents. —  Kxpres'sed    in    differential    calculus,    e  =  const,  the 

d  i 

effect  is  equal  to  a  certain  constant  multiplied  by  a  differential  of  the 
current  divided  by  a  differential  of  the  time. 

This  law  must  be  modified  for  application  to  different  forms  of 
current. 

The  opening  induced  current  from  a  faradic  coil  is  not  opposed  by 
self-induction,  and  is  more  effective  than  the  closing  induced  current. 
True  sinusoidal  induced  or  alternating  currents  which  are  svnnnetnc 
in  both  directions  are  difficult  to  obtain,  and  so  condenser  discharges 
have  been  used  in  testing  the  validitv  of  the  law.  Cybulski  and  Zanie- 
towski,  Hoorweg,  G.  Weiss,  and  Lapicque  have  obtained  widely  different 
rest  tits. 

C\'  is  the  quantity  of  electricity  contained  in  a  condenser  of  a 
certain  capacity,  designated  as  (',  which  is  charged  to  a  potential 
designated  as  V,  and  %CV-  is  the  energy  required  to  charge  it  and 
liberated  by  its  discharge. 

Prevost  and  Battelli  have  found  that  the  condenser  discharge 
necessary  to  produce  a  fatal  effect  is  determined  by  the  energy  of  the 
discharge,  or  \('V'2. 

Hoorweg1  has  found  as  the  result  of  many  experiments  that  the 
voltage  to  which  a  condenser  of  a  given  capacity  must  be  charged  in 
order  to  produce  a  minimal  muscular  contraction  by  its  discharge  may 
be  expressed  by  the  formula — 


MUSCULAR  CONTRACTION  RESULTING  FROM  ELECTRIC  STIMULATION 


ill  1  MI.DK    \I.    KI.KI    I'iJKIl'V    AM)    KOXTCEN    HAYS 

in   i»t'   lin    orain  or  -pinal  cord,  or  reflexly  by  the  stimula- 
:  -  '•   r  ot  her  nerve. 

\:  r  nf   ihi.-    effect    nf   the   electric   current  is  seen  whenever 

:   •(!•  -  .    in   the  two  hands.  ;iiul  the  muscles  of'  the  hands  and 

i   until  ence  ol  ;i   faradic  current . 

>:  i  he  nature  ol  this  effect  is  based  very  lar^elv  upon 
e\p<    i  nil  '        IMTVCS  and  muscles  of  recently  killed  animals. 

'    i  :;-'•<  i\i  TV    u:    tlii-   physiologic   effect    of  electricity   was 

,\  ho    I'liuiul    'hat     when  a    pair  of    frog's    leu's  were 

I  nes   would    ti'Uch  a   metallic  surface,  the  muscles  of 

•  h    contracted  and  the  toes  were  drawn  away  fnuu 

The      mu-cles      re!;i\ed     au'ain.      allowing      the      toes     to 

face,  ;.nd  contraction  aiiain  ensued.     This  went  on 

jierind  of  t  ime.  l)i it  t  he  coin  ract  ions  gradually  became 

\     ceased. 

:'      its  natural  saline  moisture,  t  he  object  from  which 

-•.-:»•  <  i-  <  1 .  a  nd   t  he  mei  ;il  I  ic  surface  touchi d  b\"  t  he  toes  formed 

•    ,    v.    —   current    passed    through    the   limb   and    made   the 

ci'ii't'act.      The    toes    beini:  drawn    away    from    the    metal,    the 

nd  t  he  muscles  relaxed. 

A    Complete    Neuromuscular    Preparation.    -This    may    consist 

1 1  epared  HI  -uHi  a  wav  as  to  enable  one  to  make  accurate 

•'••-•.;••.  electric  stiiuuli.     The  frog's  body  is  cut  across  at  the 

i    •:   •  •          '  Idle  i  if  the  abdomen;  the  skin  i.-  stripped  from  the  le£s 

•  ••••  p;   i  nf  t  he  bndv.     The  lower  part  of  the  spinal  column  is 

•  •-. : '  •   i-il    b      -.:•_;'    dissect  ion,   and   so   is   t  lie  en  t  ire   leniM  h   of  In  it  h   sciat  ic 

•  -.     T        ipp      p;  ri  of  the  preparation  is  fastened  to  a  stationary 
:  '1  the  table-,  while  the  foot.  or.  in  some  cases,  the  separate  tendon 

o]    the   liast rocnemius   mii-de.  is   fastened   to  some  movable  object  like 
a    .'.'.c_!i"   or  lever.     The  latter  may  be  connected  with  a  myograph  or 

it  i-  to  reiii-Ter  the  contraction  or  elongation  of  the  muscle. 

A  Simple  Neuromuscular  Preparation.     This  is  a  muscle  with  its 

n ached  to  t  he  muscle,  but  the  whole  preparation 

. '   .:.  -  .••:.  a  u  ay  a-  to  be  used  for  observation  on  t  he  muscular 

.     In     stimulation    nf    the     motor    nerve.      These 

:  not    Iv  completely   removed   from  the  body.      If 

tal  is  alive  in  some  cases,  and  then  the 

•••  thi    '  •  •    •      iid  muscle  may  be  left   undisturbed 

.'.:••  "i   i;  e  [n-oper  blood-vessels.      In  any  case 

:       '  .  u  iiile  verv  <  >ft en  the  tendon 

•  '  i :  :  i  I » i  i . 

Ma:nt  Cirrulation    in    a    Neuromuscular    Preparation. 

'      :    '      !>'•    ci  ill!  i  nil  e<]     b\"    lea\'ilm'    its    blnnd- 

I  :  e   latter  results  chl'eflv   111  all 

il !  ei'  elect  ric  stimuli  and  a  less  reai  1\' 

Fhe  Use   of   C::r;tre.      \  motion   of  a   living  muscle  under 

n-  Use  i  if  cura  re,  \\  hich 

-1       >t  •  i,i    !    ni  or  nerve  in    t  he  muscle  it  self 

lat  t  or   c;i  n     hi  •    done   <  ju  it  e 

'  '   '   '     '       '•:"'  li1  :il  canal   behind   i  he  head. 


PHYSIOLOGIC    F.FFKCTS    OF    ELECTRICITY 


3ir, 


THE  MYOGRAPH 


The    Myograph.      In    its    simple    form    (Fi.tr.  220)    the    mvogniph 
consists  of  a  lever  to  which  the  free  end  of  the  muscle  is  attached  and  a 


Flu.  220.    --Simple  tnyo^nipli  in   nprrat  inn. 

revolving  cylinder  upon  whose  surface1  the  movable  point  of   the   stylet 
traces  a  line. 


Isotonic  Contraction. — Isotonic  contraction  is  shortening  of  a  mus- 
clo  au'ainst  a  uniform  resistance.  The  re-istance  in  Fiir.  221  is  l\.<- 
w(>iji'ht  of  the  lever,  and  is  practically  the  <ame  in  all  condition-  of  the 
inu-cle.  The  muscle  is  connected  with  the  lever  at  a  point  quite  distant 


MKD1CAL     KLKCTKKTL'Y    AM)     HONTCEX    HAYS 


n',, -nun   cf   axis.    and    is   consequently   able   to   shorten   con- 
1,         :;d<T  ;ln\    influence  that   causes  it   to  contract  with  sufficient 
,    >,A, -iidit   of  tin-  lever.      It   is  upon  this  principle  that 
•  :',-n  i]-(  1-  ;i  iv  u-uall  \'  made. 

Isometric  Contraction.     This  has  reference  to  the  traction  force 

•.',..     i  1.,,'h  ends  of  which  are  fastened  to  stationary  or 

objects,   so   that    the   muscle   cannot    shorten   to 

.lent.      A  mvi  'ti'i'aph  in  which  t  he  muscle  is  connected 

.,:    (:.'•   II-YIT  Yel'Y   near  the  fulcrum   \\'ill   register  isometric 

u!>\\ard   motion  of  the  leYer  is  opposed  by  a  spring 

i-    properly    graduated    (Fig.  222").     This    method    has 

!>•  -  :  i.-ei]   to  any  extent . 

\.    •    •      ,f  :atices  on  an  isotonic  myographic  tracing  show  that  the 

d  in  certain  extents,  the  shortening  being  opposed 

'    ,          weight.      (Mi    an    isometric    tracing    vertical    distances 

certain    -nvngths    of    traction    (e<|iial    to    sustaining    certain 

,,n   the  part    of  a   muscle  which  is  not   permitted  to  shorten 


\1 


rolled  on  another  one  w 
the  registering  point  rests 
upon  the  moving  strip  of 
paper  (Fig.  22v>).  The 
cylinders  revolve  by  clock- 
work actuated  by  a  spring 
or  a  weight,  and  the  speed 
of  their  motion  may  be 
regulated  according  to  the 
rapidity  of  the  changes  it 
is  desired  to  register. 

Marey's  Drums. — A 
pair  of  t  hese  const  itute  a 
means  of  transmsssion  of 
the  motion  of  the  lever  to 

it   a  distance  by  mean-  of  pneumatic  pressure.     'These  are 
en  it   i-  convenient   to  have  the  neurornuscular  prepara- 
1  fm -d  experimented  upon  in  close  proximity  to  the  regis- 
i- i- frequent  1\- not  t  he  case.    The  part  experimented 
e  or  the  arrangements  for  the  experiment   may  be 
Mir.fm,  it  i-  often  desired  to  register  several  difi'erent 
-t  rip  of  p;i per.  ;i MI  1  it  may  be  impossible  to  group 
near  I  he  n-volvmu  cylinder.     The  additional 
quired  are  t  ho-e  reui-tei-mg  the  units  of  time  and 
!i  -ct  rie  I'urrent .     (  )t  h«-r  t  raeinu's  somet  imes  made 
a  ri-nm'  in  t  he  tK-i've  and  muscle  in  con-e(juenc(' 

.  _'_'  !    22i i    i-  a  flat .  round  liox  of  sheet  metal  s(\-d(1d 

:  ><  r  over  the  top  and  with  an  opening  at   the 

'    lorm-  a  coMiiect  ion  for  a  ruliber  tube  leading 

:n:i',    1  •> •  -e\'er;d   feet   away,     'hie  circular  side, 

hi  ad  of  t  he  drum,  i-  <  if  <<  >t'i    nil  >\  ier  so  t  hin 

'i!  ion    1  hi-   t  hat    t  he   force  of  1  he   lever  is 


PIIYSKiLdCIC    KM  KITS    CI"    KLK<  "I  KI(  Tl'Y 


A 


B 


Fig.  224. — Maroy's  drums:  .-1,  transmitter;  B,  r 

brought  to  bear  when  the  muscle  contracts.  This  compresses  the  air 
in  the  drum,  and  the  compression  is  communicated  to  the  air  in  the 
other  drum,  causing  motion  of  its  head  and  of  the  registering  lever 
connected  with  it.  The  transmission  is  effected  practically  instan- 
taneously, being  at  an  average  rate  of  2SO  meters  a  second.  Several 
of  t  he  receivers  may  be  grouped 
near  the  registering  cvlinder, 

,  , 

and  each  one  trace  a  separate 
line  upon  the  chart,  recording 
the  impulses  applied  to  the 
transmission  drums  connected 
with  different  elements  of  the 
experiment.  The  latter  may 
be  set  u])  in  separate  parts  of 
the  room  if  desirable. 

Marey's  drum  may  be  used  to  study  contraction  in  uninjured  human 
muscles.     The  drum  is  held  against  the  lateral  surface  of  the  limb  bv  a 


Ml. DK  AI.    KI.K<  TKICITY    AM)    HOXTGEN    KAYS 


itter-like  -trip  i if  -heet   metal  which  i-  bandaged  over  it.     When  the 
in  tract-  ami  -well-,   the  latter  motion  i-  t ransniil ted  through 
Maivy  drum-  to  tin-  reLii-t  erinir  apparatus. 

Time  Registration   in   Myographic  Charts.     This   may   IK-  done   in 
•  •  ,   -in  i  nli  -i  ra-e-  liy  not inir  the  time  of  starting  and  stopping  the  revolv- 


_'_'?.      .1,  Pciululuiii  interrupter;  5,  metronome  interrupter. 

Ilori/ontal   di-tances   on   the   chart   indicate   periods  of 
n  he  approximately  calculated. 

makinu  a  tntein<i  of  the  lime  units  upon  the  chart  while 
-ini:-  are  heinu1  made  are  recjuired  for  all  exact  observations. 

This  is  done  by  a  movable 
point,  which  may  be  ac- 
tuated through  the  medium 


tin.]  i  '. •-:••.  /  i-li-i-tric  -iirnal 


!i  nil-,  or  whu'h  may  he  the  end  of  a  le\'er  moved 

t  U-. 

The     Timing     M'-'hanism.      T!,;~     coii-i-t-     of    a     I  )e-pre/    electric 
iLitH'i  act  -  upon  <  inc  end  of  a  lever,  and  of  a 


PHYSIOLOGIC  KFFKCTS  OF  ELKCTHICITY 

battery  and  a  means  of  making  and  breaking  the  electromagnet  circuit 
at  measured  intervals  of  time.  This  interrupter  may  lie  a  pendulum, 
or  metronome  similar  to  the  timing  instruments  used  by  pianists,  or 
it  may  be  a  tuning-fork. 

The  Pendulum  and  Metronome  Interrupters  for  Time  Chartx. —  The>c 
are  suitable  for  cases  in  which  the  time  units  to  be  recorded  are  seconds 
or  a  large  fraction  of  a  second.  As  the  pendulum  swings  to  and  fro 
under  the  influence1  of  clock-work,  which  is  not  shown  in  the  diagram 
(Fig.'  227,  A),  the  contact  is  made  and  broken.  Kach  time  that  the  bat- 
tery circuit  through  the  electromagnet  is  completed  its  armature  is 
attracted  and  it  is  this  motion  which  is  traced  upon  the  chart.  The 
rapidity  of  the  to-and-fro  motion  of  the  metronome  (Fig.  227,  B,  and 
22S>  may  be  regulated  so  that  the  signals  occur  at  intervals  of  from  one- 
tenth  to  one  second.  Those  of  the  pendulum  are  subject  to  about  the 
same  regulation.  This  is  accomplished  in  each  case  by  changing  the 
distance  of  the  movable  weight  from  the  axis. 

The  Tuning-fork  or  Diapason  a.s  a  Time  Index  with  the  Myograph. — 
The  handle  of  the  tuning-fork  (Fig.  229)  is  securely  fixed,  while  the 
prongs  are  free  to  vibrate.  When  at  rest .  one  of  the  prongs  is  in  contact 
with  the  wire,  w,  and  completes  an  electric  circuit  through  the  batter}-,  the 
electric  signal  and  another  electromagnet,  which  is  placed  between  the 
prongs  of  the  tuning-fork.  This  electromagnet  attracts  the  prongs 
of  the  tuning-fork  and  breaks  the  contact.  The  magnetism  disappearing 
with  the  cessation  of  the  current,  the  prongs  of  the  tuning-fork  airain 
diverge,  and  the  contact  is  reestablished.  This  is  repeated  with  a 
rapidity  which  depends  upon  the  natural  rate  of  vibration  of 
the  tuning-fork,  and  this  varies  with  different  tuning-forks :  and  tin- 
same  tuning-fork  may  be  made  to  vibrate  faster  or  slower  by  fastening 
a  heavier  or  a  lighter  weight  at  a  greater  or  less  distance  from  the  end 
of  the  prongs.  The  vibration  rale  employed  is  from  one-tenth  to 
one-two-hundredth  second,  most  often  one-one-hundredth  second. 

Dexprez'x  Electric  Signal  (Fig.  2211 ' — This  is  a  little  apparatus 
which  may  be  placed  close  to  the  moving  sheet  of  paper  in  the  myograph, 
and  traces  the  units  of  time  upon  it.  There  is  a  tiny  electromagnet 
which  acts  upon  an  armature.  The  latter  is  of  very  light  weight,  and 
is  pivoted  upon  an  axis  which  is  provided  with  a  stilet  which  traces  a 
line  upon  the  moving  sheet  of  paper.  The  electromagnet  and  armature 
are  both  made  of  verv  pure  soft  iron,  to  prevent  any  permanent  mag- 
netism, but  even  then  the  armature  may  not  be  instantly  relea>ed  on 
account  of  a  trace,  of  permanent  magnetism.  A  sheet  of  paper  interposed 
between  the  magnet  and  the  armature  will  prevent  this.  A  delicate 
spring  draws  the  armature  away  when  the.  current  is  not  flowing  through 
the  electromagnet.  The  range  of  motion  is  very  slight — the  point 
of  the  stilet  moves  only  about  1  mm.,  or  .2.1  inch,  just  enough  to  make 
a  perfectly  distinct  break  in  the  horizontal  line  traced  by  the  stilet 
when  at  rest.  The  electric  signal  i-  so 
that  it  will  register  even  - ', ,/  second,  wh 
is  ever  necessary. 

Figure  2:i()  is  a  part  of  the  time  tracing  from  a  chart  made  by  the 
author.  The  breaks  in  the  horizontal  li 
i<  the  actual  si/e  of  the  tracing  upon  I  hi 
much  more  rapid  rate  would  have  to  be 
moving  at  a  much  more  rapid  rate  that 
moves  onlv  \  inch  a  second. 


TKI<   ITY    AM)    KONTOKX    RAYS 


Electrometric    Charts.-    Klectric     currents    arising    in    the    tissues 

.-•y.  of  in  consequence  of  artificial  stimulation  of  some  kind, 

i    [viii>teivil   upon  a   mvouraphic   cliart.   together  with  the  other 

of  i  lie  cxpffinieiii .      Thi>  i-  I  test    done  by  having  the  moving 

of  paper  -en-iti/rd  to  light  and  inclosed  in  a  camera,  and  casting 

mage   of    the    capillary    electrometer    upon    it.     Variations    in    the 


if  the  column  of  mercury  are  registered  upon  the  chart.     The 
if  the  elect  ronn't  ric  method  are  given  on  p.  ^22. 

Myographic  Charts. 
— Where  several  differ- 
ent factors  are  to  be  re- 
corded, the  most  satis- 
factory way  is  to  make 
the  tracing  upon  a  long 
strip  of  paper.  Hut 
where  the  character  of 
t  he  muscular  <•<  >nt  raction 
alone  is  to  be  recorded 
and  a  comparison  is  de- 
sired between  successive 
contractions,  it  is  often 
desirable  that  the  paper 
should  be  a  short  strip 
wrapped  once  around 
the  revolving  cylinder. 
A  simple  mechanism 

cylinder  >lightly  after  the  completion  of  each  revolution, 

•     ,  ••:  .at   rest  t  races  a  series  of  pa  ralli  •!  liorixont  al  lines. 

p  •    •    cch:  iii-ni  makes  an  electric  contact  at  each  revolution 

•.'•'.•  each  time  at  a  slightly  later  period.     A  convenient 

i-fumpli-diinu:  this  i-  shown  in  Fig.  2. 52.      A  cog-wheel 

•••••'.  i-  :•:-•<  ii' -d  to  the  a: \is  of  the  cylinder  and  causes 

the  n  >i  at  ion  of  allot  her  wheel  wit  h 

I'M   teet  h.      A  project  ion  at  a  cer- 

t  a  in    |  ia  rt   of  the  circumference  of 

'    i-  hit  ter  produces  an  elect  ric  con- 

tact  evi  TV  t  inn1  t  his  wheel   makes 

a    complete    revolution,   and    this 

;  '.'•-  a  lit  1  le  longer  t  hail  t  he  \\'heel 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY 


321 


with  a  smaller  number  of  teeth.  The  tracing  in  this  rase  show-  each 
muscular  contraction  separate  and  distinct,  although  the  lines  may  cross 
each  other  as  in  Fig.  233. 

EjJ'ect  of  Speed  of  Mot/on  of  the  Paper  I'pon  the  M  ijoi/rop/i/'c  Curve - 
If  the  paper  moves  very  slowly,  each  muscular  contraction  may  be 
registered  as  a  simple  vertical  line.  The  motion  of  the  level'  bring 
rapid  the  up-and-down  stroke  may  be  complete  before  the  paper  has 
moved  an  appreciable  distance.  The  tracing  of  a  series  of  contractions 
under  these  circumstances  looks  like  the  teeth  of  a  comb  (Fig.  234  j. 
Such  a  tracing  is  valuable  when  only  the  height  of  several  successive 
contractions  is  to  be  recorded,  for  instance,  in  studying  the  effect  of 
fatigue  upon_  muscular  or  nervous  excitability.  Fig.  23")  is  such  a 
tracing  showing  fatigue  from  successive  stimuli  applied  at  interval- 
of  two  or  three  seconds,  and  registered  upon  a  slowly  revolving  cylinder. 
The1,  paper  has  moved  only  the  distance  between  two  successive  lines 
during  two  or  three  seconds.  It  enables  one  to  compare  the  height  of 
a  large  number  of  contractions  at  a  glance,  but  gives  no  idea  at  all  as  to 
the  relative  abruptness  and  other 
important  features  of  the  upward 
and  downward  strokes  of  the 
stilet, 


Fig.  234. — Comb-like  tracing  upon  :i  slowly 
moving  myograph. 


Fig.  235. — Stair-rasp  phenomenon  from 
fatigue  uith  periodic  .stimuli  at  interval- 
of  two  or  three  seconds  and  with  .slow 
rotation  of  cylinder  (Weiss). 


The  cylinder  revolves  much  more  rapidly  for  this  purpose,  and  tin- 
vertical  motion  of  the  stilet  makes  an  oblique  mark  upon  the  paper. 
This    line    will    usually    be 
found   to  be  curved,  as  in 
Fig.    230.       If    the    paper 
moves  at  the  same  rate  in  a 
series    of    observations    the 
abruptness   of   the   upward 

and    downward    portions    of        Fig.  230.    -Tracing  upon  a  rapidly  revolvini:  myo- 

the  curve  will  vary  with  the  graphl 

abruptness  of  the  muscular 

contraction  and  relaxation,  and  the  entire  length  of  the  curve  will  vary 
with  the  time  elapsing  between  the  beginning  and  the  end  of  the  con- 
traction. These  features  and  the  latent  period  or  the  length  of  time 
that  elapses  between  the  application  of  the  stimulus  and  the  beginning 
of  the  muscular  contraction  are  among  the  chief  indications  furnished  by 
the  myograph. 

Registering  the  Latent  Period  of  Contraction. — Three  different 
elements  must  be  recorded:  the  unit<  ot  tune,  generally  indicated  by 
a  tuning-fork  and  Desprex  signal:  the  rlo-inii'  of  the  electric  circuit, 
also  indicated  by  a  Desprex  -iii'tial:  and  the  muscular  contraction.  In 
Fitr.  237  the  myo^raphic  tracing  is  represented  as  being  made  by  the 
muscle  (Mi  directly,  though  very  often  it  i-  made  through  the  inter- 
mediary of  a  pair  of  Marey'-  drum-.  The  mu-cle  is  stimulated  by  a 
faradic  current,  and  the  primary  current  ot  the  coil  pa-ses  through  a 
De-prex  signal  (S.S.I,  which  records  the  turning  on  of  the  current 
There  is  an  entirely  separate  battery  •  1>.2.  to  actuate  the  tuning-fork 
21 


!V22  MKDICAI.    KI.KCTHIflTY    AM)    HOXTCrEN    HAYS 

and   the   IV-pre/  -'mnal   iT.S.,1,  which  records  the  units  of  tinu — hun- 
dredth-  of  a   -econd   ii-ually.      This  arrangement    shows  the  length  of 

time    tint    elap-es    between    the   application    of   the   stimulus    and    the 

. 
res[>onse  o!  t  lie  muscle. 

A  similar  arrangement  is  em- 
ploved  for  (letermininu  the  latent 
period  when  the  stimulus  is  ap- 
plied to  t  he  nerve  m-tead  ot  the 
muscle. 

Registering  Muscular  and 
Other  Bio-electric  Currents.— 
A  pair  of  impolarizable  electrodes 
(I''..  E.  Fi<:.  2oSi  are  applied  to 
the  part  to  be  tested,  and  are 
connected  with  the  capillary  elec- 
trometer ( '.  An  arc  liu'lit  of  500 
candle-power  and  a  suitable  sys- 
tem of  lenses  and  camera  casts  an 
ima.u'e  of  the  column  of  mercury 
through  the  slit.  X.  and  makes  a 

I  !-•     -'.'57.      Mi-ii-urt-incnt     of     tin-     latent       ])!lot  o.U'raphic  record  11  pi  'II  t  he  seil- 
ntr:t.:tinii.       Myograph  arrant;...!       ^\-/(.(\     paiMT     as     the     registering 
nl    init- oj  tiiiii-.  the  appliratiiiimf  tin-  ...  ,  ...  , 

ira.ii.-.-irrcnt.  ati.l  muscular  contrartidii.  cylinder    revolve-.       All    till'   other 

elements     IliaV    be     recoixled     \lpoll 

he    paper  at  the    same,    t  ime  by  suit  able    electric    signals    and    Marey's 


••  p  ii'  •  d    includes   a   dark    room.   >mnlar   to   the   room 

I'n       '  '         '-I  '        '    '  -  ''  '  '  i  I!.;.'',     piioto- 

ln     formed    I"1     placing    a    partnion    o|    compo-boanl 

•  '     '        . :  !•  ••  ;  ' '  <:  '  .       I  hi  hi     i-    me|i  i-ed    in    a 

'•led  roinel  er     1-     placed     b'   '  Weeli     t  his     and     a 
'I'hc   l;it  ler   pa-~i  |>f"of  opfliilifr 

•  •  ••      and  for:i      i  he  leu-  of  a  reirulai1  phoii .;:  i-;i  phic 

•  .      •'.'•''.       Id'     bai'l      >l    '     i-    cami  'i'a    is   <•!<  -.-ed, 

•    whir]     '     •     1><     made    wide   or   na  rn  >w.      The 

•  :  •  111    fall-  up-  'ii  the  sensit  i/.ed 

•     I.     I'.-H  -...   \  ii,    I !»()o    ['    .V'7 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY 


323 


paper.  The  cylinder  makes  a  complete  revolution  in  from  two  to 
eighty  seconds.  The  time  units  are  registered  either  by  a  metronome, 
each  ascent  and  descent  indicating  0.37")  second;  by  a  tuning-fork 
indicating  r^  second;  by  an  electromagnet  making  twenty  vibrations 
a  second,  or  by  a  Jacquet  chronograph  indicating  one-fifth  second. 

In  making  such  an  observation  a  frog  is  narcotized  or  the  brain  is 
destroyed;  it  is  carefully  insulated  by  rubber  tissue,  and  fastened  upon 
Marey's  myograph,  and  individual  muscles  are  removed  with  the  nerves 
still  attached.  The  impolarizable  electrodes  from  the  capillary  electrom- 
eter are  applied,  and  if  there  is  a  current  of  rest,  sometimes  amounting  to 
i1,,-  volt,  this  is  counteracted  by  a  battery  and  shunt  circuit.  Then  the 
nerve  is  stimulated,  and  the  muscular  currents,  or  those  that  arise  in  the 
muscle  in  consequence  of  its  contraction,  are  recorded  photographically. 

Burdon  Sanderson1  has  done  much  valuable  work  upon  the  detection 
of  electric  currents  due  to  the  stimulation  of  muscles. 

THE   ELECTROCARDIOGRAPH 

The  Electrocardiograph. — When  any  muscle  contracts,  the  active 
part  becomes  negative  to  other  parts.  Waller,  in  1887,  first  demonstrated 
with  a  capillary  electrometer  currents  due  to  cardiac  activity  and  derived 
from  electrodes  applied  to  different  parts  of  the  surface  of  the  body. 

Electrodes  in  the  form  of  bands  of  metallic  gauze1  covered  with  woolen 
cloth  may  be  wrapped  around  each  hand,  or  a  hand  and  a  foot,  or  each 
foot,  and  when  connected  with  a  string  electrometer  will  show  electric 
currents  which  are  synchronous  with  the  aciion  of  the  heart.  The 
curve  registered  undergoes  characteristic  variations  in  different  cardiac 
lesions,  and  this  has  become  an  important  diagnostic  aid  in  the  hands 


of   the   heart    specialist.      The   various   positions  of  the  electrodes   give 
different  normal  curves. 

Kinthoven's  string  electrometer  'page  175;  depends  upon  the  deflec- 
tion caused  by  the  passage  of  the-e  weak  and  transitory  currents  through 
a  quart/  filament  tightly  stretched  in  a  powerful  magnetic  field. 
Minimal  of  Phv-iolnuv.   ls<).">.  vol.  xviii.  p.  12s. 


MKDK  AI.     KI.Ki  THK  ITY    AND    KoXTOKN    KAYS 


Nicolai  and  Huth's  portable  electrocardiograph  i  Fig.  2l->(.))  is  a  de- 
derided  impn  i\  vineiit .  'I'l  it  •  st  H  i  ig  elect  r<  >met  <  T  (page  17"))  consists  of  a 
phii  i  in  11 1 1  ti  la  1 1  n -in  I  inches  long,  with  a  n '.Distance  of  (iOOO  ohms,  stretched 
in  tlir  held  of  an  elect  romagnet  which  weighs  GO  ])ounds,  and  must  be 
actuated  1>\  a  direct  current  cit her  from  t lie  electric-light  circuit  or  from 
a  -torauc  battery.  (  M  her  parts  of  the  apparatus  arc  au  incandescent 
i  .•  ctric-liu'ht  vacuum  bulb.  1  cubic  meter.-  in  diameter,  in  which  1  here  is 
a  band  of  Wolfram  or  lungMen.  10  millimeters  long  and  l.o  millimeters 
wide,  and  through  which  pa.-ses  a  current  of  7  amperes  and  110  volts. 
The  iv-ult  iim  imlii  i-  as  powerful  as  an  arc  lamp  and  has  the  advantage  of 
ret  juirini:'  in  >  a<  Iju-t  ment . 

The  entire  lenii'th  of  the  string  is  not  shown,  only  a  portion  at  the 
middle,  which  i-  >een  through  a  slit  at  a  rijrht  anjile  with  the  length  of  the 
-trinir.  The  imauc  is  projected  by  a  Zeiss  apochromatic  1()  millimeter 
object ive  and  No.  12  projection  eye-piece,  and  a  camera  bellows  excludes 
daylight.  The  registering  apparatus  is  all  enclosed,  and  contains  a  roll 
i  if  1  in  imide  paper  <>0  meters  long  and  (5  centimeters  (2?,  inches)  wide,  with 
an  elect  ric  motor  which  draws  a  certain  length  of  the  photographic  paper 
pa-t  the  >lit  and  registers  tenths  of  a  second  upon  it  and  numbers  the  strip. 

A  Maivy'-  drum  at  the  same  time  records  the  pulse1  or  any  other 
function  de-ired.  At  the  same  time  the  record  is  being  made  the  image 


Hypertrophy  of  left  ventricle. 


lr»n     mil     h:iiii|    in   ilii-  oilier   (after   Boruttau). 


!i    a    irnnmd    ula-~   -creen,      1'i-e-siug   a    cerlain    le\'er 

•  1 "  i .  cut-  c  iff  t  he  portion  already  exposed,  and 

•  de\-e|f)piuii  ciiamber.  f  roll  i  which  it  emerges 
a    lini-hei  |   pi ct  lire. 

il  loui    lL'"i  pound-  altogether,  but  i-  made  up 
may   be  ea.-ily   handled.      It    can   all   be  placed 
|c  and  ."»(!  inche-  |<  .nu. 

pparatu-  -hoiilil  be  adju-ted  so  thai   1  centi- 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  -M-) 

the  resistance1  of  the  patient  is  to  he  measured  and  is  usually  hot  ween  200 
and  ">()()  ohms.      The  most  desirahle  leads  or  derivations  are: 

Lead       I.    Right  Arm  to  Left  Arm. 

Lead     II.   Kiu'hl  Arm  to  Left   Leg. 

Load  III.    Loft  Arm  to  Left  Log. 

I'lntsc*  of  the  Electrocardiogram. —  Fig.  241 ,  /J,  coincides  with  t  he  auric- 
ular systole:  (j,  R,  N,  and  T  with  stages  of  the  ventricular  systole,  1\  and 
T  being  the  most  important  in  diagnosis  and  always  present  in  health. 
'Flu1  spaoo  between '/-*  and  Q  is  the  auriculoventricular  interval,  and 
shows  the  time  required  for  the  propagation  of  the  impulse  through  the 


Q     5 


Fisr.  -11. — I'ha-cs  of  the  electrocardiogram. 

bundle  of  His.      Q  shows  the  ventricular  contraction  beginninu;  at  the 
hase,  and  I\  the  wave  of  contraction  reaching  the  apex  of  the  heart. 

The  ventricular  curve  gives  an  index  to  the  functioning  of  the 
limits  of  the  auriculoventricular  hundle.  described  by  the  .Japanese  physi- 
ologist, Tawara.  Electrocardiograms  are  not  directly  affected  by  movo- 


ments  of  the  blood  or  t  he  condit  ion  of  the  valves.      They  "ptnvl  v  express 
changes  in  the  electric  condition  of  the  hearl  due  to  muscular  activity."1 
By  -ome  aut  hors. 

T  is  designated  as  V . 
S  as  .). 

Interpretation    of    Electrocardiograms.      /////»/•//•«////,/    «/    tin 
Ventricle. — R.  I  (i.e.,  I!  with  Ic.-id  \o.  I     i>  a  very  -mall  iijiward  projec- 
1  Walter  H.  .lame.-  and  Hurntiu  I'..  William^,  Aiut-r.  .Itnir.  Mnl.  Sc-i.,  Nov.,  I'.Uo. 


.>'Jt>  MKDIt  AL     EI.Kl  THK  ITV     AM)     UONTGKX     HAYS 

t  ion  or  may  even  l>e  downward.  //.  Ill  is  upward  and  of  greater  magni- 
tude th;tn  normally. 

/////"  rtn>i>hn  <>f  tin  Lift  \'fntriclt.-  /.'.  1  i.-  upward  and  of  fi'reat 
hi-iirht  and  II.  Ill  i-  di  >  \vn\\  a  I'd  to  t  he  extent  of  perhaps  -  millivolts. 

H >//n  rtro/ilt'i  of  tin   iiiiriclf*  may  increase  the  height  of  I'. 

A  negative  aftrr-variat ion  or  T  is  always  almormal  and  is  often 
found  in  '/'•/..-  i'.-, •//  /-M.V/.V.  in  which  di-ea>e  it  is  an  unfavorable  sign. 

I- 


•-V 


•LEAD 


••  •    ••  '     -inu-oidal  liath-.  and  in   one  ca-e.  irpi.rtcd   (,\- 

1  .    and    all    I  lii-    ca-e-    were    1  icnefif  ed. 
\  di   '  i  tii  in  N  nf  1 1. 1  in  1  .'_!.">  m  i  Hi  vi  >lt  i-  el  i;iract  eristic 

"'    '"•'••'    irn.^ln  niii.       It    i-  nf  ]i-—   fre(|i]rni    i  ,c,-iirrence 

"•    i    <-nr<i;<,<    ,,.       •        l,,r  \l,nn,«l  >!,.  «\  . 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  327 

An  insufficient  positive  after-variation  T  in  many  organic  cardiac 
or  arterial  diseawx  is  improved  by  sinusoidal  baths  (Strubel). 

Rapid  puke  shortens  the  diastole  represented  by  the  distance  be- 
tween T  and  the  following  P,  and  is  extreme  when  P  and  T  coincide. 

Irregularities  of  cardiac  rfujtfint  are  clearly  shown,  also  extrasystoles 
and  pulsus  bigeminus.  \'entricular  extrasystoles  sometimes  give  a 
high  T  wave  followed  by  an  N  wave  extending  far  below  xero.  Com- 
pletely irregular  heart,  nodal  rhythm,  or  pulsus  irregularis  perpetua  show 
several  small  diastolic  waves  in  each  cycle  without  any  normal  P  wave. 
This  is  thought  to  indicate  that  the  trouble  is  due  to  auricular  fibrillation 
(James  and  Williams). 

In  arterial  hypertension  and  renal  sclerosis  the  ventricular  contrac- 
tion is  slow  and  jerky,  and  also  in  mitral  stenosis.  Functional  trouble 
of  the  auricles  and  aortic  insufficiency  are  clearly  shown.' 

Experimental  section  of  one  limb  of  Tawara2  produces  an  enormous 
increase  in  ventricular,  E.  M.  F.,  and  an  approach  to  a  diphasic  curve 
with  a  gallop  rhythm.  James  and  Williams  give  the  electrocardiogram 
of  a  patient,  with  possible  lesion  of  the  right  limb  of  Tawara.  The 
patient  has  moderate  hypertrophy,  dyspnea  increasing  for  the  last  five 
years,  second  aortic  sound  accentuated,  no  murmurs,  but  gallop  rhythm. 

H.  Yaquez's  investigations  show  no  information  as  to  the  energy  of 
the  cardiac  contractions/' 

Experiments  by  U.  H.  Kahn1  and  by  Eppinger  and  Rothberger"1 
show  that  the  currents  produced  by  the  two  ventricles  are  in  opposite 
directions;  and  Rothenberger  and  Winterberg  show  that  these  currents 
are  not  synchronous,  and  that  the  different  phases  shown  in  an  electro- 
cardiogram correspond  to  the  contractions  of  the  different  portions  of 
the  heart.1'' 

The  heart-sounds  and  the  electrocardiogram  have  been  registered 
together  by  R.H.  Kahn,7  who  finds  that  the  first  sound  falls  between 
A*  and  T:  the  second  sound  begins  -^  second  after  the  end  of  T. 

Pachon's  left  lateral  decubitus  is  desirable  for  electrocardiograms. 

A.  Lohmann  and  AI.  Rinek  give  practical  directions  for  the  use  of  the 
string  galvanometer  and  photographic  registration  of  the  same.s 

Dr.  Walter  B.  James  and  Dr.  Horatio  H.  Williams  in  this  country 
have1  made  important  contributions  to  its  clinical  use. 

Duhamel  has  invented  an  electrocardiograph  provided  with  a  dial 
and  needle." 

Currents  of  Action  in  a  Muscle  During  Tonic  Contraction. — The 
current  has  about  the  strength  of  ,  nV,,  Paniell  cell,  and  the  wave  of  nega- 
tive variation  has  a  speed  of  between  1  and  7  millimeters  per  second.1" 

Currents  of  Action  in  the  Ureter.-  Triple  phase  currents  have1  been 
demonstrated,  corresponding  to  the  peristaltic  waves  in  the  ureter.11 

1  H.  Moulinior,  C.  R.  S,x>.  do  Biol.,  Ixxi.  1M4.  .July   I.  1911. 
"  Kppinuor  and  Kothbor^or.  Zoithsoh.  f.  klin.  Mod.,  Ixx. 

3  C.  K.  do  la  Socioto  do  Biol..  Ixxi.  12  X.  .July  1,  1911. 

4  ( Vntralblatt  fiir  I'liysioloajo.  xxiv.  7l2X.  <  )otohor  129,  1910. 
••  Ibid.,  10.")-:;,  I'Ybnmry  4,  1911. 

fi  Ibid..  9.-)9,  .January  7.  1911. 

7  . \rohiv.  fur  dio  ^os.  IMiysiolotrio.  oxxxvii,  .">97.  1010. 

8  Archives  fiir  Physiologic,  1.  417,   1910. 

9C.  K.  do  la  Soo.'do  Biol..  lx\.  10(1,  January  :21.  1911. 

10  Th.  v.  Briioko.  Archiv.  fiir  die  gesmn.  Physiol..  1910.  oxxxiii, 

11  L.  Orboli   and    'I'h.    v.    Briioko.   Aroliiv.  fiir  dio  ^osain.   Thy: 
p.  344. 


•  >->  MKDICAL    KLK<  TKKITY    AND    HONTGEN    RAYS 

Currents  Produced  by  Cold  Applied  to  a  Nerve. — The  portion  of  a 
nerve  which  i-  cooled  l>econie-  positive  to  any  other  part.1 

Contraction  of  the  Separate  Muscular  Fibers.  -This  is  a  process  of 
traii-ver-e  thickening  and  of  longitudinal  shortening,  and  is  probably 
connected  with  ;:  diemic  change  in  the  protoplasm  which  is  rapidly  re- 
_•••••;••';  alter  i  hi  contract  inn  ha.-  ceased. 

Contraction  of  a  Striated  Muscle.  Thi-  occurs  under  the  influence 
;  ric  -;  i  I  us.  u>ua  11  v  as  a  shortening  and  swelling  of  the  entire 


nj:  :it  tin-  cathode  extrein- 


ave  of  swell  in  g  advancing  along 


lling  at  one  end  of  the  muscle.      Th 


xperimentally  at  the  beginning 


t  on  may  be  pr 


.••••:.•   t  hn>uu'h  t  he  rectus  abdnminis  muscle  of  a  frog, 
ed    out    and    pinned    to    two    cork-.      Impolarizable    electroiles 
hi    n-ed.      This  muscle  present-  transverse  tendinous  septa,  and 
•  . '._  »;  the  passage  of  a  ci  >n-t  ant  current,  from  one  end  of  the 
'  •  ' '  •  •    >t  hei    a  -welling  is  seen  at  the  cathode  end  of  each  niusfu- 
ti<>ti      l-'iir.   -H   .      A    -weiliim  i-   pro(luc(>d  at    the  end   where  the 
mu-cular   -ectiou.      It    di-appear-.   and   a   .-welling 
••'    '•  •    nth   r  end  of  each  muscular  section  when  the  current   is 
ill'] 

-.:•".. pie  of  ;i  LiTea!   law  in  regard  to  bipolar  electric 
' 

•tioii    in    -trial ed    muscle   arises   at    the   cathode 

de.  and  at  1    '    •  :  "d.-  when  t  he  curreiU   is  broken. 

1  h"   p  natun      if    muscular  <•<  mi  ract  i'  m    is 

^ 


_J 


'•  ;-;•  OUT:I|)!I    l-'iu.  -J  i:,  .     The  mu-de 

point   and   t  he  i  \vo  •  |i  ci  rode-  are  applied  near 

:  •'•>•<  •  '-Hon    lake-   place   in   the  half  of 

1  '  i   \\  hen    t  he  current    i-  m.-ule, 

'     anode   01    j,,,Hi  ive   electrode   i-  apjilied 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY 


32'.) 


F.  W.  Frohlich1  finds  that  when  both  electrodes  arc  applied  to  one- 
half  of  a  muscle  which  is  fixed  at  its  middle  point,  contraction  takes 
place  first  in  that  half.  It  subsequently  occurs  in  the  other  half.  Con- 
traction in  the  first  half  ceases,  and  the  process  of  restitution  begins 
while  contraction  is  still  present  in  the;  second  half.  This  partly  explains 
why  the  greatest  muscular  contraction  is  never  obtained  from  a  single 
stimulation. 

The  Refractor]/  or  Latent  Period  of  Mn*cnl<ir  Contraction.  —  A  small 
period  of  time  elapses  between  the  application  of  the  stimulus  and  the 
occurrence  of  muscular 
contraction.  This  occurs 
both  when  the  stimula- 
tion is  applied  directly  to 
the  muscle  and  when  it  is 
applied  to  the  nerve.  In 
the  former  case  it  is  about 
one-five-hundredth  sec- 
ond. In  the  latter  case 
there  is  added  to  this  the 
time  occupied  in  trans- 
mission t  h  r  o  u  g  h  the 
nerve,  and  this  averages 
about  30  meters  a  second. 


7 


i.  J4b.  —  Latent  perio 


of  contraction  whon  the  muscle 

timulated. 


The  latent  period  is 
measured  by  means  of  a 
myograph  on  which  are 

recorded  the  units  of  time,  the  making  of  the  current,  and  the  occurrence 
of  contraction  when  the  electrodes  are  applied  to  the  extremities  of  the 
muscle  itself  (Fig.  24(0. 

The  latent  period  in  frog's  muscles  at  ordinary  temperatures  is  about 


one-two-hundredth  -ecotid:  it  i-  -holier  at  hiuh  temperature-  and  lonuer 
at  lower  tempera  t  ures. 

The  time  con-limed  in  the  transmission  of  the  stimulation  through  a 
certain  lenul  h  of  nerve  i-  mea.-ured  by  the  inyou'raph.  u]>on  which 
tracings  of  the  units  of  time,  the  makinu  of  the  current,  and  the  occur- 

1  Hi,  HI.  f,7.  May  ti.  Km.". 


MKDICAI.    KLKCTHICITV    AM)    KONTCiKN    HAYS 


rence  of  contraction  in  the  >ame  muscle  when  the  electrodes  are  applied 

at  two  different  part-  of  the  motor  neives  ( Fiir.  247)  are  recorded. 
Two  separate  measurements  of  the  latent  period  are  made,  changing 
the  po-ition  of  the  electrode-.  The  difference,  in  fractions  of  a  second, 
between  the  two  latent  period.-  found  in  this  way  is  due  to  the  time 
con-timed  in  tran-mit  tint:  the  stimulation  through  the  length  of  nerve 
between  the  two  different  part-  at  which  the  electrode-  are  applied. 
1 1  iima n  nerve-:  transmit  impul-e-  at  the  rate  of  about  .">()  meters  a  second. 
/:,<!'•  mi  ni' tin  I.nt<  at  l'<  n'o<l  of  tin  M  usclt  a/nl  ,,f  i/n  \crrc  r/x»i  the 
•'.1  ft  niitintj  Currents.-  Alternations  more  rapid  than  ~)()0()  to 
the-econd  do  not  produce  muscular  contraction,  because  the  effect  of 
the  current  in  one  direction  may  not  have  time  to  develop  before  it  is 
-•;ppres-ed  by  the  current  in  the  opposite  direction. 

7V. i    /."<•'    /'•  -iutl  i >f  tin    S/iitnil  Cord.      \\y   thi-   is   meant    the  time 

[>ied  hv  the  cord  in  receiving  an  impulse  ironi  the  stimulation  of  a 

-ensofN    nei'vc.  and  in  sending  out    an  impulse  through  a   motor  nerve1. 

I'    ;-  the    lime  required  hv    the  spinal  cord    tor    the  performance    of    its 

re'1'  \   fund  i>  ins. 

I'  ired    by    mean-    of    the    invograph.      Kleetrodes    from    a 

I'e  applieil  t..  the  motor  nerve  near  the  spinal  cord  and  the 
latent  period  of  contraction  noted. 
'1  he  electrodes  are  then  applied  to 
the  sensory  nerve  near  the  spinal 
cord,  and  the  latent  period  of  Con- 
traction is  aiL'ain  measured.  The  in- 
crease m  time  required  in  the  latter 
case1  ]••  due  to  the  latent  period  of 
the  spinal  cord  (Fig.  24S).  The 
latent  period  of  the  cord  is  about 
:'  ';""li  "f  ""  ^'ihal  twice  a;  much  as  that  of  the  whole 

lengt  h  of  the  nerve. 

'/'. .    Mnxcitlar   ll'n n  .-- \  striated   mu.-cle  whose  nerve'  is  stinmlated 

either  at  some  part  oi  its  course  of  at  its  insertion  at  the  motor  point  of 

:;iU>c]e  -i -i       i          contracts  simultaneously  in  all  part.-  if  it   is  in  a 

condition,      ('ertain    diseased     condii  ions,     prim-ipallv    of    the 

thi.-   and   caii-e  the  contraction    to   progress   irraduallv 

'  •'  .    "H1     pai-'    ii]    the    mu.-cle    in    another.      I'oi.-onin^    b\-    curare  also 

IJ    "Me.  -  eftect   by  paraly/.iii'j:  the  motor  plaques,  the  terminations 

• ''    '  '  •     fie;    '    '•"•:-    u]ii  in    t  he    individual    muscular   liber-. 

•  '    m  d«  r  normal  condii  ions  a   wave  of  com  faction  t  ra verse's 

'  i  '•  application  ,,|  a  si  in  ml  us.      Thi-  i-  associated  wit  h 

I  he   wave  of  com  ract  ion    i-   sho\\  ;i   b\-    means 

litider.  one  end  of  the   lever  re-t  in-  upon   t  he  lateral 

fid  in-ii  lien  the  muscle  -wells  and  show- 

•     •'  con:  ract  ion   has  reached  t  hat    point . 

'"  !'  d  that   inu-ciilar  com  ract  ion  means  .-hort  enint!; 

and  o|  t  he  mu-cle     a  change  of  fonn,  not  M  e'hange  in  volume 

1   m  polar  -tim  illation  \\  ltd  the  anode  t  here  i-  a  peri  polar  /one  of 

a   polar  area  of  relaxation.      There  i>  quile  the  o|)])osito 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  331 

Unstriated  or  involuntary  muscles  arc  commonly  in  a  state  of 
contraction  and  show  a  diminution  of  t his  tonic  contraction  at  t he  anode 
when  a  constant  current  is  turned  on,  and  a1  the  cathode  when  this 
current  is  broken.  The  muscles  of  the  intestine  are  examples. 

Differences  in  Electric  Conditions  Produce  Differences  in 
Muscular  Contraction.  —A  continuous  current  turned  on  with  gradu- 
ally increasing  strength  must  he  made  very  strong  to  produce  any 
contraction.  A  very  weak  current,  if  abruptly  made  and  broken  or 
changed  in  direction  or  changed  in  strength,  will  produce  vigorous 
contraction.  In  some  cases  the  direction  of  the  current  has  an  effect 
upon  the  contraction  produced.  Muscular  contraction  is  produced  by 
the  variable  period  of  an  electric  current,  not  by  the  constant  period  of 
the  current,  either  maximum  or  minimum. 

Monopolar  stimulation  is  effected  by  placing  one  electrode  upon  the 
muscle  or  nerve  while  the  other  is  applied  10  some  indifferent  part  of  the 
animal  at  a  distance  from  the  first.  The  diffusion  of  the  current  in  The 
immediate  neighborhood  of  the  active  electrode  takes  place  about 
equally  in  all  directions.  There  is  neither  an  ascending  nor  a  descending 
current  in  the  nerve1  or  muscle1.  A  muscle  responds  about  equally  well 
to  positive  or  negative  monopolar  stimulation,  but  a  nerve'  or  the 
motor  point  of  a  muscle  shows  a  markeel  difference  between  negative 
and  posit  ive  monopolar  stimulation. 

Contractions  Occurring  at  the  Making  or  Breaking,  Closure 
or  Opening,  of  the  Constant  Current. — There  is  an  anodal  openim: 
contraction  when  the1  e'lirrent  is  broken  while  the1  anode  is  upon  the1 
muscle  or  nerve  and  the  cathoele  is  upon  some  indifferent  part  of  the1 
body.  The1  other  designations  are1  cathoelal  opening  contraction, 
anodal  closure1  contraction,  and  anodal  opening  contraction.  The-  names 
indicate  the1  active1  electrode1,  or  the  one-  whie-h  is  applied  to  the  muscle 
or  nerve,  ami  whether  the  circuit  is  closexl  e>r  ope'iied. 

NORMAL  ELKCTRIC   KKACTIONS  AND   DESIGNATIONS  OF  THESE  CON- 
TRACTIONS 

ENGLISH.  EKKXCII.  GKKMAN. 

Catluxlal  orkathodal  clos-     (Closure,  .fermat ure;  con-      Closure.  .Schliessung; 


,,r  KCC.  ES  or  KES. 

Anodal    opening    contrac-     Opening,  .ouverture  AOS.     Opening.  .Offnung  AOZ. 

tion  AOC. 
Anodal     rlnMiii:     contrac-     AES.  ASZ. 

tion  ACC. 
Cat  liodal  or  kathodal  clos-     CaET  or  KET.  KST. 

urc     tetanus     CaCT     or 

KCT. 
( 'at  liodal  or  kat  hodal  open-     CaOS  or  KOS.  KOZ. 

ing     contraction     CaOC 

or  K( )('. 

AOC  and  ACC  arc  not   far  from  tM|tiul.  and  the  lat  !cr  is  given  as  the  greater  in 
many  tallies  of  this  kind.     Ca('( '  is  much  st  rouge r  and  CaOC  much  weaker. 

REACTIONS  TO  ELECTRIC   STIMULATION  IN   NEUROMUSCULAR 
PREPARATIONS 


;};•;_>  MKDICAL  KLECTKICITY  AND  RONTGEN   HAYS 

liirht  current  may  be  modified  '•>"  rheostats  and  volt  controllers  so  as  to 

SITVC  the  -a  me  ]  »un  >o-e.     Having  made  the  proper  connections  by  means 

of  suitable  electrodes.  a  ver\'  weak  currenl  is  turned  on.  and  then,  alter 

•    >    inu  continuously  for  several  second-,  it  is  turned  off.      A  convenient 

u  ay  of  closing  and  openim:  1  lie  circuit  is  by  means  of  a  Morse  telegraphic 

key.      \\itii    the   weake>t    cm-rents   no   muscular  contraction   occurs   at 

any    time.      A-    the    stivnmh    of    the    current    is    gradually    increased, 

'    usclilar  ci  in!  ractii  >n-  be^m  to  take  ]>iace.      (  >ne  notes  the  strength  of 

•;,.     current    required   to   produce  contraction   when   the  electrodes   are 

iish    placed  and  when  the  current   is  made  or  broken.      Normally, 

tin     weakest    current    thai    \vill   ]>roduce  a   muscular  contraction   at   the 

<•'.'  •-•;->•   or   turning   on   of   the   circuit    with    the   cathode   as   the   active 

-    led   to  the  nerve  will   not    produce  any  contraction   with 

•.(•n  the  current   is  opened  or  broken,  or  with  the  anode 

when    1  he   circuit    is   either   opened   or   closed.      And    with    neither   the 

ile  or  the  anode  as  the  active  electrode  will  there  be  any  contrac- 

tioi     ';'.::rr_r  the   H.I\V   of  the   current. 

The  fir.-i  change  thai  is  noted  as  the  current  is  increased  is  that  the 
cathodal  closure  contraction  increases  in  strength,  and  that  anodal 
opening  coin  rad  ii  >n  occurs. 

I'    requires    a    -till    stronger   cnrrent    to   excite   anodal    closure   con- 

•  :  •:..      \nd  wit  h  an  ext  remely  strontr  current  cat  hod  a  1  closure  tetanus 

occur-.     This   is  a  continued  contraction  following  the  closure  of  the 

'.  ;  ml   lastinti:  an  a]»]>recial)le  lenir'h  of  time.     The  other  contrac- 

':•:.-     i:n-nt  i-iTii-d     have     been     apparently    instantaneous     shortening. 

i::.r:  •  •:'    lei;     followed   by    rdaxatiiin. 

The  eff.-ci  MI  the  -t  j'oi  itTesI  current  -uite<l  for  .-ucli  experiiiKMits  is  to 
p!'od  .'•••  c;  "  '  i  ulal  o]ieniim  cont  ract  n>n. 

"<     '   '  ••          '   i-  an  al)breviation  for  the  -latenient  tlsat 

cat  !  i  1  1;  ,  c]i  i~  ire  coiit  ract  ion  re<  pure-  a  currenl  ot  at  lea-t  5  miliianiperes. 
Form   of   the    Myographic   Tracing.      Kadi    muscular  contraction 
'    •  •  '      •       •        '     i  he    myi  iLii'a  ;  iliic    i  I'aci  nn:    They  a  re  a  refrad  or 


t    ail 


;     /  '  '    /"    • "      •  .      (  'halite       -.    lei    perat    ii'i     act    in    a    Vei'V 
'  i11  •  i-lit  of  i  hi  ;raphic 

cill'X'e        !     dllteivn;     tel        ii  ,.-.     ;V,  ,,,, 

I'll  "I    (  >.    \\  '•;-  ~.        I'in               '.i    t  c, 

1"       "  i          i     i                          and   the 

'    '  '  '                                     ;s-  applied 

^,__\ '     i::'(  •  '  a  I    to   avoid 

I  he     illfllielici      o]      :  a  '  !  .'    ,.   .         The     effect 
the     I,  ,  ire     i-     to 

\,.,-\        |nUch 

•  irai  ion.       \     •  id\    of  i  his 

a'    bet  \M-I.JI        .",       ,-,]),]    1 1      i  \      . ),,,    fref/inM- 

• '      MO        •  , , 1 1   occiii-.   and    a  i    M      (       ; t 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY 


333 


maximum  contraction  occurs.  From  0°  to  19°  0.  tho  height  of  con- 
traction diminishes  slightly,  and  from  10°  to  3S°  ('.  (the  temperature 
of  the  human  body)  it  rises  again  to  the  same  maximum,  liaising  the 
temperature  beyond  3S°  ('.  the  muscular  contractility  is  seen  1<>  full  very 
rapidly  and  completely  disappear;  and  at  the  same  time  the  muscle 
ceases  to  return  to  its  original  length  after  each  contraction,  but  tend- 
to  pass  into  a  state  of  persistent  cont  ract  ure.  The  latter  condition 
may  be  permanent  if  the  muscle  is  not  cooled  quite  promptly. 


I'LT.  L'.")0. — Wave  of  contraction  at  different  temperatures  C.  (isotouie)  (Weiss'. 

Fig.  250  from  (I.  '\Yeiss  shows  the  comparative  height  of  muscular 
cont  raction  following  equal  electric  stimuli,  but  at  different  temperatures. 

The  effect  of  temperature  upon  the  response  of  muscle  to  electric 
stimulation  is  modified  by  the  rapidity  and  direction  of  the  changes  of 
temperature  and  by  the  conditions  under  which  the  muscular  work  is 
accomplished.  This  is  true  both  of  single  muscular  contractions  and 
of  experimental  tetanus.1 

Influence  of  Fatigue. — Z.  Treves2  has  made  experiments  which  go 
to  show  that  the  progressive  diminution  in  the  amount  of  work  per- 
formed in  a  unit  of  time  by  a  muscle  under  electric  stimulation  of  its 
nerve  is  due  more  to  nervous  than  to  muscular  fatigue. 

Influence  of  Resistance. — The  greatest  height  of  contraction  is  pro- 
duced when  a  suitable  small  resistance  is  to  be  overcome,  such  as  a 
small  weight  to  be  lifted.  Electric  stimulation  produces  contraction 
when  there  is  no  weight  to  be  lifted  or  when  the  weight  is  increased 
within  certain  limits,  which  are  sometimes  quite  extensive.  A  heavy 
weight  prolongs  the  period  of  ascent  and  >hortons  that  of  de-cent,  and 
with  a  very  light  weight  the  period  of  descent  may  be  very  long. 

!-J.rt<-nxil>ili/>i. — The  extensibility  of  a  paralyzed  muscle  is  independent 
of  its  electric  excitability.  K.  Overtoil  has  shown  that  removal  of  all 
the  sodium  chlorid  in  the  muscular  substance  renders  it  completely 
inexcitable.  Motonosuke  (!oto8  has  studied  the  extensibility  of  muscles 
paralyzed  m  this  and  other  ways,  and  finds  it  unaffected. 

I\t/'<  ft  (  /mn  Kexixtdnci    In  liupiurc.      I  he  resistance  ot 
rupture  during  contraction   from  electrization   is  eoual   to 
the   breaking  strain   of   the   muscle   when   at    rest,   and   the 
contraction  when  stimulated 


.].  C'arvallo  and  C.  Weiss,  (' 

is'.l'.i.  ;md  fisti.  .Inly  'J'J.  l.sW. 

•:  Aivhiv.  ill  [•'isiolojria,  '_'.  'J-JT, 
;  Xcit.  f.  Hiol..  4ti.  :•>'.»,  I'.KU. 
'•.I.  C'arvallo  aJid  G.  Weiss,  (' 

IS,  l.M'li. 


1.  titiO.  .Juiv  lo. 


MKDIfAL    ELKlTHUITV    AND    RONTGEN    HAY: 


Wave  of  Muscular  Contraction. —  A  muscle  stimulated  at  anyone 
!><>int  u-uailv  contract-  in  every  pail,  hut  I  his  contraction  may  not  take 
place  everywhere  -imult  aiiei  iu-lv.  Aebv  ha-  ]>laeed  two  myographic 
levers  at  ditVerenl  part>  of  a  l"iiLr  iinisde  and  lias  sometimes  seen  the 
levers  move  at  different  limes,  indicating  the  progress  of  the  transverse 
swelling  and  longitudinal  shortening,  which  is  called  the  wave  o{  mus- 
cular  contraction. 

Single   muscular  fiber-  ob-erved  under  the  micro-cope  show  a  pro- 

i:re--ive  wave  of  transverse  swelling 
under  the  stimulus  of  an  electric  cur- 
rent  (Fi<r.  2:,i  i. 

Stimulation  of  the  nerve  does  not 
, n  ;„  a     cause  a  wave  of  mu>cular  contraction. 
.       iilx  r.  All    parts    of    the    muscle    contract     at 

once.     The  sai.'e  is  true  of  stimulation 

at    the   motor    pi-int    of    the    muscle,    since    this    is    really   stimulation 
th:-"ULrh  tin    nerve  at  it-  p!a<-e  of  subdivision.     Stimulation  of  a  mu.-cle 


of  contraction:  and  stimulation  of  a  curari/.ed  nerve  always  does. 
Tip-  wave  "t  contraction  in  living  human  muscle  travel.-  at  the  rate  of 
about  in  to  i:;  meter-  a  second.  •  S  >e  pa <re  !•}:•}().) 

DuBois-Reymond's    Law.      DuBois-Revmond  s     law    is    that     the 

muscular  contraction   i-  influenced  by   the   magnitude  and  -uddemiess 

f»f    the   change    in    the   >  trench    of   ;  he   current.      Many   circumstances 

modify    thi.-    and    make    the    mat  hematic    application   different    in    the 

•.-   forms  under  which   the  current    is  applied,  such  as  condenser 

irire.-.  indiici  d  currents,  and.  inierrupteil  galvanic  currents.      1  Jiffer- 

eni     :  >ri\    das    have    been    found    hv    various    observers    to    corre.-pond 

clo-i-l\   with  the  results  of  t  heir  experiments  under  t  he-e  different  con- 

..'.••:.-.      No  one -implc  formula  suilices  even  approximately  for  every 

condition.       Sec  al-( i  pau'e  '.]  1  '2. 

Nature  of  Nervous  and  Muscular  Excitability.     The  stimulating 

•••  •  •    '•  •  h  ctrici?  \    ,pon  a  nerve  or  a  muscle  is  doubt  less  due  to  a  change 

ti-.-ue,  and    tin-    i-   -iippo.-ed    to   be   of    the   character 

'.'••    :    b\    '    e   term   electrolytic   ii-ed    in   ii-  broade-i    sense.      There  is 

•  .  _    .  • .  '•     'f  ion-  and  en-ncc  in  i    e  osmotic  piv-.-ure  inside  i  he 

:     i  lie    nerve-tiber.-.      ( 'hemic    st  Hnuli    t  •:  •  »duce    'heir 

•  ner. 

•  '  •:;  eri     i  pi  MI   mu.-cle  i-  -In  >\\  n   }<-    1 1  e  demon.-t  rat  ion 
'      i      I'  '     '11   after   1  lie   a]  iplicat  \>  <\\    has   cea-ed.   and   even 

:   '  '  '    '    '  '      '  _•  -    li:a\    be   \  i-il  ,|e  to   t  he  mien  »-n  .pe. 

"'  :'  i terve-fiber  under  ult ra-n i i<'ro-copic  e\a nii nation   pro- 

'     'ii.  but  no  \'i-ible  change  in  t  he  colloid  ainieai-ance.1 

"in/    '  '  :    -  :    \\n    -ah-  in  different  animal  cell-  when  it  reaches  a 

.      •         •     '      tin     all  lUinmoid- .-uflicient  1\   to  produce  a  -tiinula- 

'  N    .  ation     m  nerve  or  inu-cle.      .\(  rn-t'-  theorv  is 

.'      :•         be  n  ,n   idi  red  a  -erie-  of  cell-  -,  pa  rated  by  -e'mi- 

•  •  •  •  •  . 

I  i.i    osmotic   pressure   in   mu-cle-   i-   rai-ed   -oinetime-   a-   much  as 
ian     ci  ntimeti  i          i       i  he  mu-cle  i-  ih  ;,   -tate  of 

I  loli.  |   |,i       ,     .  |  ]ri||      i-      m'e-ite-1      \\  hen 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  335 

longed  and  strong.     It  is,  perhaps,  the  chief  factor  in  the  development 
of  fatigue. 

Application  of  Electric  Stimulation.— The  stimulation  may  he 
applied  indirectly  through  the  intermediary  of  the  nerve  or  directly 
to  the  muscle  itself.  In  the  latter  case  the  result  is  due  partlv  to 
electric  stimulation  of  the  muscular  fibers,  but  largely  to  stimulation  of 
the  peripheral  terminations  of  the  nerve-fibers.  The  effect  of  the  latter 
may  be  eliminated  by  the  administration  of  curarin.  an  alkaloid  which 
paraly/es  these  motor  plaques. 

Stimulation  of  a  Muscle  or  Nerve  through  the  Unbroken  Skin 
('Monopolar  Stimulation).  -A  small  electrode  is  applied  to  the  surface 
of  t  he  l)od v  over  the  course  of  the  nerve  or  over  t  he  muscle,  and  another 
electrode,  which  may  be  larger,  is  applied  at  some  distant  indifferent 
part.  The  influence  of  the  current  at  the  active  electrode  is  greatest 
near  this  electrode,  and  becomes  weaker  as  the  lines  of  force  spread  out. 
in  every  direction  through  the  body.  This  creates  a  difference  in  the 
nerve  or  muscle  by  an  electrolytic  action,  and  under  certain  conditions 
demonstrable  contraction  is  excited. 

Point*  of  Election  or  Motor  Point*.  -These  are  the  places  upon  the 
surface  of  the  body  whore  the  application  of  the  active  electrode;  results 
in  the  strongest  muscular  contraction.  The  motor  point  of  a  muscle 
generally  corresponds  with  the  point  at  which  the  motor  nerve  enters 
it,  and  divides  into  its  terminal  ramifications.  Stimulation  at  the 
motor  point  is  really  stimulation  of  the  motor  nerve,  but  limited  to  the 
individual  muscle.  If  the  active  electrode  is  small,  the  current  of 
moderate  strength,  and  the  motor  point  accurately  found,  the  individual 
muscle  may  be  made  to  contract,  while  the  neighboring  muscles  remain 
relaxed.  This  is  one  basis  of  the  use  of  electricity  in  diagnosis  and 
treat  ment. 

Chart*  of  the  Motor  Point*.  -These  are  more  or  less  diagrammatic 
pictures  of  different  parts  of  t  he  body,  showing  the  motor  points  according 
to  Krb's  classic  observations.  They  are  of  service  as  a  general  guide, 
but  the  exact  localization  is  partly  a  matter  of  experiment  in  each  case. 

Degree  of  Excitability  to  Percutaneous  Stimulation.  The  normal 
degree  of  sensitiveness  of  the  muscle  or  nerve  to  the  make  or  break 
of  I  he  current  is  t  he  same  as  thai  given  on  p.  331  in  describing  t  he  effect 
upon  exposed  nerves  or  muscles. 

The  Strength  or  Height  of  Contraction.  The  strength  of  con- 
traction under  the  different  conditions  of  polarity  and  opening  or  closure 
of  the  circuit  follows  the  order  of  their  appearance  as  given  in  the 
table  (p.  331).  The  cathodal  closure  contraction  is  normally  the 
strongest  of  all. 

Minimal  and  Maximal  Contractions.  Taking  any  individual 
phase,  such  as  the  cathodal  closure  contraction,  and  tracing  its  magnitude 
by  means  of  the  mvograph,  we  find  that  a  weak  current  produces  no 
contract  ion  at  all:  that  the  weakest  current  thai  will  excite  any  con- 
traction at  all  produces  a  minimal  contraction,  and  that  as  the  current 
is  increased  in  strength  a  maximal  contraction  is  obtained,  which  is 
not  surpassed  bv  further  increasing  the  strength  ot  the  current. 

The  production  of  the  minimal  contraction  is  called  by  the  French 
the  threshold  of  contraction. 

Some  muscles  do  n<>t  contract  at  all  unless  a  current  strong  enough 
to  produce  a  maximal  contraction  is  applied.  1  he  cardiac  muscle  is 


'.Wi  MKDK'AL    KLK(  TKK  ITY    AND    RuNTGEN    RAYS 

an  example,  and  if  tin-  auricle  of  a  frog's  heart  is  completely  separated, 
ii  si  in  n  cea-es  in  heat  spontaneously,  but  may  he  stinnilated  to  contract 
hv  an  electric  current;  hut  oiilv  the  inaxinial  coinractio!i  i>  known. 

['he  effect  of  a  series  of  stimuli  in  rapid  succession  is  to  progres- 
sivt:l\  increase  ...iit  of  contraction.  There  is  a  limit,  however, 

i-  reached  in  a  very  -hurt  time,  and  then  the  effect  of  fatigue 
becomes  apparent  in  a  diminished  hemht  oi  contraction. 

|-    is  the  same  in   regard  to  the  maximal  contraction.      The  greatest 

if    cunt  ract  i  n     thai    can    he    produced    by    a    single   stimulus    is 

exceeded     if    successive    .-limuli    of    the    strength    required    to    produce    a 


maximal   contraction   are  applied.      Fiu.  2~>'2  is  a   myographic   tracing 

with  a  slowly  ivvolvim_r  cylinder,  and  stimuli  applied  at  such 
sh  >r!  intervals  that  we  i:'et  the  effect  of  an  increase  above  the  maximal 
coin  racTi'nn  from  a  single  stimulus.  The  stimuli  applied  are  all  espial, 
lull  the  iiei^ht  of  contraction  increa.-es  pro<ii'essi velv  up  to  a  certain 


A 


-     .-•     •  .'inir  iinTf-u-ini:  hi'itrlit  MI"  inu-cular  runt  ract  inn  \vit  h  inrrcas 

t  •  • ;  r  n  • : ,  1  I                    nil        I                                  •  <         irnui     i  t  -    ( i\v  1 1     1 1  <  i  r  i  x<  ii  1 1 : 1 1    1  i !  1 1 

•  '    •  '     ••                                 liairram  at  t  hr  thinl -timulat  inn.     All  ],<  mtrli  t  Ii 

•  ,       '  ri-a-i-'i.  tl:i-  -linrili  arc  apjilii          I     m  /   intcrvaN  am 

•  '          '  '  '  •    p-lTi-i-1    ill    :i    rai.ii  I    -eric-   n!'   -tiinuli  \\  hii'li    >\.  nil.  I  iiif-rca-c    t  Ii 


it:     ni-1  •'•  a  certain  limit    in  consequence  of  fatigue. 

1    -    Lf •").'!  .•       '         •         pon  a  rapidly  revolving  cylinder. 

Electric    Muscular  Tetanus.      If  stimuli  are  applied   in  such  rapid 

•  III  >ll     ha-     Hot     ce;--eil     bi  'fi  il'e     t  he     IH-Xl      Ci  >n- 

1    '    •    ci  iiidii  ion  uf  com  inueil  emit  ract  ii  in  which 

!:';-.        I  hi-   ci  itidii  i'-t.    doe-    not    impl\     :  he    pi-ex-nce   nt'    1  he 

lied    tet  aim-,  all  hoti  as  one  of 

I  iii       I'paretit       •  .          ci  ini  ract  ion 

'  •  •    the    tetanus 
I  In      mu.-ciilar 

•  !;.c  • 

'<••'.<••••'  I  i.M!          ' 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  337 

and  ;i  sufficiently  rapid  scries  or  alternations  will  produce  tetanus  with 
very  weak  currents. 

The  height  of  the  continued  contraction  in  electric  tetanus  is  much 
great  IT  t  han  the  maxima]  cont  faction  from  the 
strongest  single  stimulation  (Fig.  254). 

Xot  only  is  the  contraction  produced  by 
periodic  stimuli  stronger  than  that  from  a 
single  stimulus,  but  it  is  more  easily  excited. 
Periodic  stimulation  of  the  exposed  sciatic 
nerve  in  a  frog  will  excite  reflex  contraction 
of  the  muscles  of  the  opposite  limb,  while  the 
strongest  single  stimulation  will  not  do  so. 

The  Production,  of  Electric  Tetanus. — J.  ( 'ar- 
vallo  and  G.  Weiss1  believe  that  the  magnitude  of  the  successive?  stimuli 
is  of  greater  importance  in  the  production  of  tetanus  than  their  fre- 
quency, and  that  its  determination  is  easier.  Both  factors  are  essential, 
however,  in  the  case  of  a  unidirectional  current,  as  well  as  in  the  case 
of  the  periodic  (alternating)  currents  from  an  induction  coil. 

Submaximcd  Tetanus  of  Striated  Muwlcs. — A  striated  muscle  under- 
goes a  series  of  uniform  contractions  when  it  is  subjected  to  a  series  of 
maximal  stimulations.  A.  SamojlofF  finds  that  less  powerful  electric 
stimuli  produce  a  series  of  unequal  contractions,  and  that  the  inequality 
does  not  follow  any  definite  law. 

Maximal  and  Submaximal  Contraction. — The  greatest  amount  of 
muscular  contraction  which  can  be  caused  by  a  single  electric  stimulus 
is  called  maximal  ntuxcidar  contraction. 

Any  smaller  amount  of  muscular  contraction  is  known  as  snhmaximal 
muscular  contraction.  A  maximal  stimulation  is  produced  by  an  elec- 
tric stimulus  powerful  enough  to  produce  maximal  contraction. 

A  series  of  maximal  stimuli  from  an  induction  coil  produces  a  tetanic 
contraction  whose  myographic  tracing  is  a  regular  curve:  but  when 
weaker  induced  currents  are  used,  the  tetanic  contraction  makes  an 
irregular  and  trembling  trace.  Cooling  a  muscle  causes  the  tetanus  to 
become  regular. 

A.  Basler3  has  shown  that  the  sartorius  muscle  of  a  frog  is  easily 
put  into  submaximal  tetanus  by  weak  faradization  of  its  nerve,  while 
a  much  more  slowly  interrupted  or  alternated  current  will  produce 
tetanus  only  with  a  current:  which  is  strong  en< nigh  to  produce  a  maximal 
contraction.  Submaximal  contraction  becomes  a  continuous  tetanic 
contraction  if  the  stimuli  occur  as  rapidly  as  27  times  a  second,  while 
maximal  contractions  do  not  become  continuous  unless  the  stimuli  are 
as  tivquent  as  ;i4  a  second.  The  myographic  chart  made  with  between 
27  and  :->4  interruptions  a  second  shows  a  continuous  fused  tetanus  with 
weak  currents,  and  a  serrated  tetanus  with  strong  currents.  Basler 
explains  this  on  the  theory  that  the  weaker  current  stimulates  only  the 
thin,  slow,  easily  excited  muscular  fibers,  while  stronger  currents  stimu- 
late the  rapid  fibers  which  are  more  difficult  to  excite.  The  frog's 
gast rocnemius  muscle  does  not  answer  for  this  experiment. 

The  effect  of  alternat  ing  or  of  interrupted  direct  currents  is  to  produce 
exactly  the  same  muscular  tetanus,  provided  the  successive  alternating 
^Journal  <lt>  Physiologic  «'1   .!.•  Pathologic,    1,   IS'.)1,),  443. 

2  Arch.  f.  Physio*!.,  oTJ,  ivi'.t. 

3  Arch.  f.  .1.  ies.  Physiologic,  1  ().->,  :m.  l'.K)4. 


;. ;;s  MKOHAL    KLKCTRK  ITY    AND    HONTUEN    KAYS 

currents  :uv  exactly  similar  except  as  to  direction.     Carvallo  and  Weiss1 

have  tested   ihis  fact    l.y  means  of  a   dynamo  of  special  construction, 

irivin"  uniform  periodic  "currents,  either  direct  or  alternating. 
Tripolar  Stimulation,    This  consists  in  the  application  ot 

electrode  from  one  pole  of  the  battery,  and  of  a  forked  electrode  or  two 

electrodes  from  the  other  pole.  The 
single  electrode  is  applied  between 
the  other  two.  In  such  a  case  the 
forked  electrode  is  the  more  active, 
and  it  will,  for  instance,  prevent  the 
occurrence  of  elect  rot  onus  due  to  the 
middle  electrode  when  the  applica- 
tion is  made  to  an  exposed  nerve 
(Fig.  2.~)f)). 

It  affords  a  means  of  producing 
an  effect  upon  a  deep-seated  nerve 
without  diffusion  of  the  current. 

Set<chenow,   in    ls«i.-),  and    B.  Werigo2  have  especially  investigated  the 

elf i  >•;   of  t  ripolar  si  imulat  ion. 

Peripolar    Stimulation. —This   occurs    when    a    small    electrode    is 

applied  over  the  middle  of  a  nerve  or  muscle  in  an  uninjured  limb,  and 


;i  larire  electrode  i.-  applied  to  t  he  opposite  .-ide  nf  1  lie  limb.  In  Fig.  2")(i 
the  negative  electrode  is  over  the  muscle.  The  direction  of  the  current 
thro  ,  ii-de  i-  f roii i  hot h  ends  toward  the  center.  I  M"  course,  all  the 

c:i    ;•«•!,•!     im  1  in-  lar.^e  indifferent   po.- it  ive  elect  rode  does  Hot  u'o  to  the  two 
end-  "I    ;  he   mu-cle,  as  the  diagram   would  indicate,   but    ivallv  s]»reads 
''It    I!'"!      i  i;.'      :.  tde  ;il id.  enterhm  I  he  liei'Ve  or  muscle  at     rnallV  different 
j'  >.:.•        '  •        '  •  ••  muscle,  t"  leave  :;   chiefly  at    a  point  as  near 

•        '        !  lie    cal  ho(le. 

I:  '  produced   in   the   nerve  or   muscle   the  same   tripolar 

.'    liie    in  t  Ve   or    niil>i-le    had    been    e\po>cd.    and    a    >ini:'le 

.    been   applied   between   t  wo  electrodes   from  the 

Virtual  or  Physiologic  Electrodes.  The  electric  current  passing 
:'••.''•'  .  ::  'in  either  end  toward  I  he  center  may  be  regarded 
:  ['  •  ;  •  •  '  .  •  •  :  >h\'.~ii  T  'trie  eject  ri  >de  at  eit  her  ext  remil  y 

•    ect  rode   at    i  he  center.       The  names  virt  ual 
'•r  pli        •  ••":•-  indicate   iln-   place  . -it  which  1  he  current  enters 

I     .••.        |,    [•]  v      ,'    .  •     i,.  I'ntli.il  .   is'.i'.i 
-  An  :     /•         i1:    .  .    '.  ..  ..-.  !.   r,\7,    IV((». 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  339 

and  leaves  the  muscle  after  having  passed  through  the  different  struc- 
tures of  the  limb  from  the  places  where  the  real  electrodes  are  applied. 
The  real  electrodes  are  the  metallic  or  other  terminals  from  the  two 
poles  of  the  battery. 

It  has  already  been  stated  that  the  single1  middle  electrode  in  tri- 
polar  stimulation  is  deprived  of  much  of  its  effect,  and  that  the  outer 
forked  electrode  is  the  active  one.  This  condition  prevails  to  a  certain 
extent  in  peripolar  stimulation  and  may  explain  the  phenomenon  of 
the  reaction  of  degeneration. 

Nature  of  the  Electric  Current  Employed. — Variations  in  the 
strength  of  a  galvanic  current  produce  muscular  contraction  the  height 
of  which  increases  with  the  amount  and  abruptness  of  the  change  in 
the  strength  of  the  current. 

Induced  currents  provoke  contraction  and  are  very  readily  applied, 
either  as  isolated  induction  shocks  or  as  the  periodic  discharge  from  a 
faradic  coil. 

Faradic  excitability  may  be  lost  and  galvanic  excitability  retained 
in  certain  diseased  conditions,  or  the  reverse  may  be  true.  These 
deviations  from  the  normal  yield  important  information  as  to  the  con- 
dition of  the  nervous  and  muscular  systems,  and  furnish  indications  for 
the  proper  electrotherapeutics  application. 

The  primary  current  of  a  faradic  coil  is  an  interrupted  galvanic; 
current  with  a  high-tension  element  due  chiefly  to  the  self-induction 
occurring  each  time  the  current  is  broken.  This  form  of  current  may 
be  used  to  excite  muscular  contraction. 

Yon  Helmholtz's  faradic  coil  has  the  connections  of  the  primary 
coil  so  arranged  that  there  is  never  a  complete  break  in  the  primarv 
circuit.  At  a  certain  stage  the  current  passes  through  the  primary 
coil  in  full  force,  and  at  another  stage  a  large  part  of  the  current  is 
diverted  through  a  shunt  <>f  low  resistance.  The  object  of  this  is  to 
eliminate  the  self-induction  occurring  in  the  primary  coil  when  the 
current  is  completely  broken,  and  make  the  variations  in  strength  of 
the  primary  current  equal.  The  reduction  and  increase  in  the  primary 
current  being  of  the  same  quantity  and  abruptness,  the  currents  induced 
in  the  secondary  coil  at  these  two  phases  of  the  primary  current  are 
equal.  A  faradic  current  from  such  a  coil  does  not  have  the  polarity 
which  characterizes  that  from  an  ordinary  faradic  coil.  There  is  no 
difference  in  the  effect  upon  muscles  or  nerves  whichever  is  the  active 
electrode,  while  with  the  ordinary  faradic  coil  the  currents  in  one 
direction  are  much  stronger  than  those  in  the  other. 

CORTICAL  STIMULATION 

Epileptiform  Convulsions  Produced  by  Cortical  Stimulation.— 

Stephane  Leduc1  shows  that  intermittent  currents  of  low  tension 
applied  directly  to  the  cortex  of  the  brain  will  produce  the  group  of 
symptoms  typic  of  epilepsy.  He  thinks  it  practicable  to  study  the 
effect  of  different  therapeutic  measures  upon  this  artificially  induced 
epilepsy. 

.1.  1>.  Prevost  and  J.  Mioni'-'  have  studied  the  effect  of  thyroideetomy 
upon  the  epilepsy  induced  in  young  animals  by  alternating  currents. 
They  find  that  it  prolongs  the  stage  during  which  cortical  stimulation 

1  Arch,  tie  mod.  dcs.  Infants.  12,  771.  October  2.'),  HH)4. 
2C.  R.  dt>  Soc.  de  Biol.,  58.  *)'.»,  January  14.  1905. 


•>K>  MKDICAL     KLK<  THIelTY     AND     K(")NT(iKN     HAYS 

produce.-  tonic  c,,nvul:-ions  without  clonic  convulsions.  The  adminis- 
tration of  thvroid  extract,  on  the  contrary,  cau.-es  clonic  convulsions 
to  f.  .iio\v  ci  >r\  icai  M  imulat  i'  >n. 

/'.  -•  Sti  tn /ilfitinn  "l'<i  ('inttr  tn  ff«  C'n  Hex  of  the  Brain. — 

A.  »  i.  <  iri'-boiedi -tV1  made  .'In  or  IN  experiments  upon  kittens,  trephining 
''..  skull  and  L;  li. e  cerebral  cortex.  In  4  cases  he  found  a 

center  in  the  upper  pan  of  the  gyru>  antecniciatus.  where  stimulation 
wa.-  folloued  1>\  more  or  less  profuse  perspiration  of  the  opposite  side 
i»l  the  body,  la.-i  in  live  or  ten  ntiiuites. 

The  -ame  re.-uh  wa.-  obtained  in  a  colt  by  stimulating  a  center  about 
the  -;,:>  of  a  -ilvi  r  Id-cent  piece  in  front  of  the  motor  area.  Ligature 
M]  •  ,.  hlood-ve-.-els  '  'f  a  limb  did  not  ]>  re  vent  sweat  in::'  when  t  he  cerebral 
center  v,  as  -t  ii  ilated.  X  t  -it  her  did  t  lie  use  of  curare  prevent  muscular 
coin  ract  ion. 

Man  nit  til*  tiffin  .l/'/.v/i .-:  of  flu-  fci/c  front  Stimulation  of  the  Cortex 
<  ''  ••  •  Urn  >.  It,  du  Hois-Kevinoiid  aiul  P.  Silex2  have  studied  this 
-ultject,  and  find  that  in  do^s  there  are  three  different  centers  when; 
electric  Mill  illation  produces  movement  of  the  eye.  One  i.-  the  visual 
-pi  ere,  allot  her  i.-  a  point  in  t  he  center  for  movements  of  the  neck,  and 
er  i.-  in  the  center  for  movements  of  the  face.  Stimulation  of  the 
fir-1  •  \vi  •  produce  associated  movements.  Stimulation  of  t  he  last-named 
pi-oduce-  isolated  movements.  The  visual  sphere  has  to  do  only  with 
movements  which  normally  accompany  the  exercise  ot  the  visual 
funci  ion. 

STIMULATION  OF  THE  CEREBELLAR  PEDUNCLES 

I-'.  If.  Thielle1  fiiid.-  that  this  pi'oduces  movement  principally  of  the 
milM'les  on  i  he  same  -nle  ol  the  bod\\ 

Cerebellar    Localization    by    Electric    Stimulation. — (1.  Pairano4 

that   there  tire  two  special  areas,  one  for  the  upper  extremitv  on 

the  same  -ide,  and   the  other  for  the  posterior  extremity  on   the  same 

-id'-.       The  firsl  i»l  these  i-  located  at  the  middle  and  lateral  part  of  the 

vi  •      .  - :  the  other,  a  lit  1  le  hack,  mi  t  he  base  of  t  he  lateral  lobe  near  t  he 

Stimulati  'ii  ol   these  area.-  does  not   produce  spasmodic  move- 

•    ent-.    but     attil  ides    maintained    by    a    mu.-cular    contracture.      The 

[M.-I  ii-e   may   b<-  one  nf   flexinn   or  extension,   adduction  or  abduction, 

iM-les  may  be  involved  as  to  indicate  that   manv  centers 

are    grouped    in    a    very   small    area.      The-e  centers   are   at    some   little 

.  :•  :  '•  • . .       I  •  •    co  nt  ract  lire  may  be  modified  bv  the  will.      Another  lea  tun.' 

'    'ii    oi    i  he   anterior  extremity   ot    the    vermi-   i>   exaltation 

.    •'       •      '•        :    :   terror,  but   no  forced  or  at  axic  movements,  although 

r  •!•••  •  '.•'.'   reaction  to  noi-cs  01-  other  -li^ht  external  causes. 

|p  Itation  theiv  i.-  vertigo,  and  the  do«r  upon  whom 

tried    bark-   and    whines.      !•  rom    this   experimeill    it 

•      .  i    the  anterior  part   of  the  vermis  normally   pla\'s  an 

important  role  m  the  different  emotions  and  in  their  expre--ion. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  341 

ELECTRIC  STIMULATION  OF  THE  SPINAL  CORD 

V.  Decceshi1  stimulated  the  spinal  cord  of  a  frog  l>y  means  of  shocks 
from  an  induction  coil,  and  measured  the  contraction  of  iho  gastrorne- 
niius  muscle.  The  latter  was  much  reduced  if  a  weak  solution  of  sodium 
chlorid  was  caused  to  circulate  through  the  blood-vessels  of  the  spinal 
cord.  This  reduction  took  place  with  hypotonic  solutions,  or  those 
of  a  strength  less  than  the;  normal  ,fi(y  of  1  percent,  contained  in  the 
l>loo<l.  A  greater  strength  of  salt  solution  caused  an  increase  in  electric 
excitability,  which  may  even  amount  to  tetanus,  and  the  animal  may 
even  die  from  exhaustion.  These  effects  may  be  due  to  the  physical 
effect  of  dehydration  of  the  nervous  tissues  by  hypertonic  salt  solution 
and  imbibition  caused  by  hypotonic  solutions. 

J.  Joteyko's  experiments-  upon  the  fatigue  of  the  nervous  centers 
by  electric  stimulation  show  that  the  centers  in  the  spinal  cord  are  at 
least  twice  as  resistant  as  the  peripheral  terminations  of  the  nerves. 

S.  Baglioni3  shows  the  importance  of  the  presence  of  oxygen  to  the 
functions  of  the  spinal  cord.  The  isolated  spinal  cord  of  a  frog  loses 
its  excitability  in  an  hour.  Hut  this  persists  for  twenty-four  or  thirty- 
six  hours  in  a  gaseous  or  liquid  medium  rich  in  oxygen,  such  as  oxygen 
gas  under  pressure  or  water  through  which  a  current  of  oxygen  is  passing, 
or  a  solution  of  !!.,().,. 

The  Excitability  of  the  Spinal  Cord. — The  excitability  of  the 
spinal  cord  adapts,  itself  to  the  intensity  and  periodicity  of  the  stimula- 
tion. (1.  and  A.  Pari4  find  that  reflexes  excited  by  the  stimulation 
of  a  centripetal  nerve1  are  usually  equal  if  the  stimuli  are  equal.  If, 
now,  the  stimuli  are  markedly  changed  in  strength,  there  is  at  first  a 
corresponding  change1  in  the  rehVx  effect,  but  later  the  latter  returns 
to  the  original  strength.  The  spinal  cord  as  a  reflex  motor  center 
adapts  itself  to  the  strength  of  the  stimulation  applied,  and  after  this 
adaptation  has  taken  place  the  same  reflex  effect  is  produced  by  a  weak 
as  at  another  time  by  a  strong  stimulus.  And  the  minimum  stimulation 
which  will  produce  a  reflex  effect  depends  upon  the  strength  of  the 
stimulus  to  which  the  cord  has  previously  been  subjected. 

A.  Pari:'  has  found  that  the  automatic  oscillations  of  excitability 
in  the  centers  in  the  cord  have  a  tendency  to  synchronize  themselves 
with  the  rhythm  of  a  periodic  stimulation.  Rhythmic  stimulation 
of  the  nerve-centers  causes  a  rhythmic  muscular  contraction,  but  the 
latter  is  of  an  oscillating  amplitude:  strong  contractions  alternate  with 
weaker  ones.  This  is  due  to  physiologic  alternations  in  assimilation 
causing  rhythmic  alternations  in  excitability,  and  if  these  are  not  of 
the  same  rapidity  as  the  rhythmic  current,  they  spontaneously  be- 
come so. 

Uterine  Contraction  from  Stimulation  of  the  Spinal  Cord. — 
K.  ( 'hidishimo6  finds  that  electric  stimulation  of  the  spinal  cord  below 

•  origin  ot  the  tenth  dorsal  nerves  causes  the  movements  of  the  uterus 

become  regular  and  more  energetic  whether  they  are  excited  directly 

reflexly. 

He  has  sought   in  vain   to  find  a  center  in  the  cortex  of  the  brain 

:;.x4,  May  _>l),  1x99. 


342  MKDH  AL    ELECTRICITY    AND    RONTGEN    RAYS 

when*  stimulation  will  cause  uterine  contraction.  Stimulation  of  the 
dura  mater,  however,  re  ("-n  forces  uterine  contractions. 

He  ha-  found  no  such  center  in  the  medulla. 

Loss  of  Excitability  in  the  Spinal  Cord  in  a  State  of  Degeneration.  — 

IV-truction  of  the  motor  area  in  the  brain  is  followed  within  eight  days 
by  complete  lo—  of  faradic  excitability  from  stimulation  of  the  internal 
cap-tile  or  of  the  peduncle-  of  the  brain.  (Vera  Norowska  Oscherowitsch, 
experiment-  upon  dogs.1  ) 

Variations  in  the  Excitability  of  Motor  Nerves.  —  Nerve-fibers 
undergo  chanii'e-  in  excitability  when  various  salts  are  applied  to  them, 
and  thi-  change  is  associated  with  modifications  of  structure  and  color- 
ability. 

Effect  of  Carbonic  Acid.  —  Waller'  concludes  from  his  experiments 
that  electric  reactions  in  a  nerve  are  increased  by  small  and  diminished 
1  >y  la  rsi  e  <  jtiant  it  ie-  of  carbonic  acid. 

}'<>i  '"/>>  '  >."«/  firotorcrdtrin  have  many  physiologic  effects  in  com- 
mon. but  yohimbin  prolongs  the  refractory  phase  while  protoveratrin 
increases  the  electric  variation  of  a  nerve  which  is  stimulated.  Studies 
with  the-e  two  substances  lead  .1.  Tait  :  to  conclude  that  the  refractory 
period  corresponds  with  the  period  of  electric  variation. 

I  'oi-oninu  by  oxalic  acid  destroys  the  faradic  excitability  of  the  vagus 
nerve  in  warm-blooded  animals.1 

Loss  of  Nervous  Conductibility  from  Narcotics.  —  General  anes- 

thesia  from  ether,  chloroform,  morphin,  chloral,  alcohol,  or  other  drugs 

rediice.-  i  lie  conduct  in'_r  ])i  >wer  ot  the  nerves  and  may  complete!  v  abolish 

it.      "1  •  e  iattej    takes  place  abruptlv.  having  been  preceded  by  a  certain 

stair1'      '    which    the    nerve    i-   easily    fatigued    by    strong   and    frequent 

ind  [ceil   c  .'.>•:.'-.      'I  he  same  changes  t  ake  place  when  the  n;i  ret  it  ic  is 

tniln    nerve,  but  !•'.  \\  .  Krohlich  and  J.  Tait6  find  that. 

to  it-  abundant   vasculariu  ,  tin-  intact   nerve  i.-  very  resistant  to 

•••-. 

l.'M-al  iti'-xcit  abilin  i-  apparently  more  easy  to  produce  bv  the 
top  c;  .  a  pphcat  ion  i  .i'  ;i  na  rci  >t  ic  than  lo.-s  of  conduct  ibil  it  \'. 

\  .  '  •      eases  the  latent  or  refractory  period  intervening 

•  n   tin    ajiplicat  ion  i»]   a  stimtdu.-  and   the  resulting  muscular  con- 

•  1  . 
I- 


Cocain    ha-   n    i-elcciive   action   upon    the  different    fiber-  of  a   mixed 

'  laments     are     paralv/ed     before    the    motor;    the 

-    oi    the-    pneumo^;i-!  ric    betoi'i1    the    ascending:    vaso- 

•    ••    '  ••    •      od    :itor-.  mid  bronchocoiist  rictoi>  before  broiifho- 

dil    '  i  i    upon  t  he  nerve-fibers,  and  not  like  that  of  curare 

Up'  'II    the  i-ni  l-p!ate-   i  ,f  t  he   nerve.11 


n    i|i-   vui«-   inTvi'U-i-  crntnili-  r 
•:         ••  •  p   :;'.»:;   Julv  •_>:;    imo 

'  C.  •,•-  ill  !  .-•  •    |'|  •..;,,!'.  12,  74."),  rvbru:ir\  4.   iVt'.t. 

•   I  .  .;••  rmirnt  il   I'hy-iol.  nry.   iii.  L'LM.   I'.tlO. 

1  I{.  (         ;          .    '•     :  •    lili'-h,  .  \n-liiv    fur  f\]MTiiiic:iiullc  I'lithuluuif  and  Pharma- 
.      -  •.      11"    1  '.  1  1  I 
.1      .-:.         :      I'!    .  '     If   I1  Ltd  .    I'.!!).", 

'     I  );\    HI,    .1         .!  •      I  '•      .       ,'._•'..      I'.tnl.     -\'l.     M',. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  343 

Influence  of  Fatigue  on  Electric  Excitability.—,!.  Joteyko's  experi- 
ments upon  the  fatigue  of  the  nerve  terminations'  show  that  these  are 
much  more  rapidly  fatigued  than  the  muscles  when  an  induced  current 
is  used. 

Influence  of  Circulation  Upon  Nervous  Exhaustion.— K.  Taskinerr 
shows  by  experiments  upon  frogs  that  while  a  muscle  with  circulation 
regains  its  excitability  in  three  to  six  hours  after  complete  exhaustion,  a 
muscle  without  circulation,  but  in  an  atmosphere  of  oxygen,  regains  its 
excitability  only  partially.  A  rapid  rhythm  exhausts  a  muscle  with  cir- 
culation sooner  than  one  without  circulation.  A  slower  rhythm  than 
once  every  four  or  five  seconds  is  more  favorable  to  the  muscle  with 
circulation. 

Influence  of  Traction  Upon  Nervous  Excitability.— The  electric  ex- 
citability of  a  nerve  is  diminished  by  traction  upon  it,  differing  in  this 
respect  from  muscular  excitability.3 

Electric  Response  of  the  Nerve  to  Two  Successive  Stimuli.— 
Francis  Gotch  and  J.  Burch'  have  made  electrometric  measurements 
of  a  nerve  subjected  to  rapidly  repeated  stimuli.  The  nerve  docs  not 
give  an  electric  response  To  a  second  stimulus  unless  there  has  been  a 
sufficient  space'  of  time  since  the  first  stimulus.  This  period  varies 
with  the  temperature  of  the  nerve.  At  4°  ('.  the  smallest  interval  is 
O.OOX  second:  at  2°  C.,  0.012  second;  and  at  about  15°  ('.,  it  is  0.002 
second. 

This  has  an  important  bearing  in  explaining  the  lack  of  sensation 
and  motion  from  the  application  of  high-frequency  currents,  in  which 
the  impulses  occur  in  opposite  directions  at  intervals  of  less  than 

i.ouo.ooo  second. 

Delay  of  Electric  Response  of  a  Nerve  to  a  Second  Stimulus.— 

The  greatest  delay  occurs  when  the  interval  between  the  two  electric 
stimuli  is  17|:>0-0  second.5  And  S.  Levinson  has  further  experimented 
with  two  electric  stimuli,  the  first  producing  a  marked  but  not  a 
maximal  contraction.  With  intervals  varying  from  0.  to  0.0004  second, 
the  two  stimuli  reenforce  each  other.  Longer  intervals  result  in  a 
lesser  contraction  than  if  only  the  second  and  stronger  stimulus  were 
applied,  and  beyond  a  certain  still  longer  interval  the  result  is  the  same 
as  if  only  the  second  were  used.'1 

Effect  of  Heat  and  Cold  on  Nervous  Excitability. — K.  Pretschis- 
tenskaja7  has  found  that  the  electric  excitability  of  the  vagus  nerve  is 
tolerably  uniform,  within  quite  wide  limits.  It  is  diminished  either 
above  or  below  these  limits.  Heat  or  cold  does  not  increase  its  excita- 
bility beyond  the  normal. 

(1.  Brodie  and  W.  D.  Haliburtons  have  studied  the  effect  of  heat 
upon  muscles  and  nerves.  The  electric  excitability  of  muscles  and 
nerves  and  their  negative  variation  and  other  electrophysiologic  proper- 
ties disappear  at  about  the  temperature  of  40°  C.  in  frogs.  47°  ('.  in 

1  C.  R.  Soc.  do  Hiol.,  eleventh  series.  1.  oSG.  May  ;_>().  1S99. 

-  Skandinavisrhos  Archiv.  f.  Physiologic,  vol.  xxiii.  p.  1.  1000. 

3(1.  Weiss.  C.  R.  Soc.  do  Hiol.. 'tenth  series,  (i.  lOo.  February  11,  1>>99. 

4  Journal  of  Physiology .  xxiv.  417-421),  1>99. 

5  P.  (iotch.  Journal  of  Physiology,  xl,  p.  2.10.  1910. 

6  Arrhiv.  fiir  die  gesani.  Physiologic,  exxxiii.  2t>7.  1910. 

7  Zeit.  f.  Kxp.  Path.  u.  Thorapio,  47,  s7.  p.  97.  190."). 

8  Journal  of  PhvMologv,  :V2,  473,  190f>. 


;VH  MF.DICAI,    KI.Kl  TRIi  ITV    AND    RONTGEN    RAYS 

mammal-,  and  •">(  f  ('.  in   l>inls.     The  difference  is  due  1<>  the  varying 
coagulability  of  the  proteid  <ubstances. 

,1.    C:irv;dln  and  (I.   Wei--1    have  experimented  upon  the  influence 

of   tn  ipi    ..";:>•  upon   the  di-app<-ai  aticr  .-did  reappearance  of  muscular 
contractilitv. 

Mare\   -  '.'1  a  very  -lowly  revolving  myo^niphic  cylinder  were 

;     •     •     ,-••'••   v. .-.-    -tin  ulateii   by   i  he  -econdary   current    from   an 

•'    •     ci  il.      A    •<••  . ien-er  wa-  discharged   through   the   primary  of 

ie\v  M'coiids.       I  his  inithiiil  <>f  i  /i  rf  rifii// '/  xti/i/it- 

:  ;   -•••.-  >>  ,  <!' A  r.^fin  rn I .  mid  prey<  nt  s  polar  or  elect  ro- 

!•.•;••  .•;•'••'••-.      T'.e  em   was  performed  upon  a  frotr's  ua.-t  rocne- 

•...-.••      •  I'iiii   pinned  tn  ;i  piece  uf  \\  i H H  1  ;ind  placed  in  a  vessel 

•<  ••  [H  r;  •  ire  cuiild  IK-  i'e<rulate<l.  A  \\'ei^ht  nf  K>  grains 
v\  a-  '  :•  :  tn  4 :  e  :•  mi :  ! .  In  a  living  1  i'"i:  \vit  h  the  sciat  !<•  nei'\'e  cut .  hut 
4  ,i- ci;-i  •  '.  iniaiM  at  -1 '  tn  2")  ('.  muscular  excitability  was  practi- 

1  e\!       i-Iili  e.    b  ;'    ;;!    !ii>i    thei'e    was    a    slight    lllci'ease    111    elect  1'ic 

•  d  by  a  decrease  with  a  subsequent  increase  to  about 

••••  original  height  of  muscular  contraction.     This  latter 

'.•  •_    '  •  maintained  for  a  very  ]»im  time.     Fatigue  takes 

•    •   temperature  is  raised  or  lowei'ed.      It  nccui-s  very  rapidly 

a'  M     (  '..'•'.'   I'l'in  fact  ilit;    instantly  I'eturns  on  raisin<r  tlie  temperature 

tn  _'  i    <  .      1  he  same  fatigue  occurs  at  .'!()    ( '..  but  1  here  is  not  the  same 

recovery  on  reducing  the  lemperatnre  from  this  level  to  20°  C.     2.  A 

f fi  1^  which  i-  cut   in  two  to  stop  the  circulation  presents  similar  results. 

lor  instance,  at  il    (  .  it   take-  only  one-halt  hour  for  fatigue  to  reduce 

the  elect  l       i    •:.'  :  act  ility  ti  >  zero. 

Effects  of  Cold  Upon  Speed  of  Nerve  Conduction. — The  accepted 

formula  >  I.i'ir.  K   -    u  —  lit.  <:  and  l>  bein.tr  constant>  for  most  tempera- 

ture-.      And   at    two  different   temperatures.  10"   ('.  apart,   the  ratio   is 

between  1  to  2  and  1  toil.      ( 'old.  t  hen.  trreat  ly  -lows  the  t  ransmission  of 

The  ratio  i-  >imilar  to  that   of  the  effect   of  cold  upon 

in    chemic   reactions    \ant  Iloff's  law  •.  but   many  exporinicntors 

•     '    n-uard  it   a-  a   purely  physical  as  di>tiii|iuished  from  vital  phe- 

Effect   of   Alternating   Currents.      A   closin.ir  and   sometimes  also 
•:,    ••    ;••-    place    when    an    alternating   curi'ent    of 

Stimulation  of  a    Muscle  Which  is  Completely  Separated  from 

the  Bod  v.  'h*  til  id-  that  the  effect  depends  upon  the  portion 

'  '  •     current     i-    applied.      The    <rreatesi    effect 

1   when   t  he  eli  'ct  i'i  ides  a  re   ap]  died 

i  nt  t  ra  verses  the  lent:!  h 

effect         produced   when   hot  h  elect  n>des  are 

Elei  trie   Contractility  of  Striated  Muscle  After  Death.     .!.  Bab- 

•    :    ci    prr-ent   a  pliiiM-  in  \\  hich    t  heir 

I'i    t  In      liill-cle     i-    re  I  ained. 

•'•••'     Volt  a  ic    excit  ahilit  V    >  elt'C- 

a  vi      :        '  •'  •  ,  ' '  • !.        T!  e   rear]  i'  in   i  >\  <\  ailiei] 

:  .  •:.  i-   ACC     i  ',-,(  (    and  '  'a( '(       A<  X '. 

Mai  (      -     '   '  •  •       '   '  '  '        mi    result-  in  t  he  sum1  \<  .urnal. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  345 

Stimulation  of  Nerves  by  Electric  Currents  of  Very  Brief  Duration. 

—Louis  Lapicque1  finds  that  the  contraction  produced  by  a  very  brief 
electric  stimulation  is  exclusively  a  closure  contraction. 

J.  L.  Hoorweg-  calls  attention  to  the  fact  that  the  muscle  is  not  a 
mere  elect rodynamometer.  indicating  tho  strength  of  the  nervous  impulse 
arising  from  stimulation  of  the  nerve,  but  is  itself  excitable.  Knge]- 
m aim's  observation  in  1X71,  that  the  ureter  which  is  of  nnst riped  muscle 
devoid  of  motor  nerve-fibers,  obeys  t  he  same  laws  of  electric;  excitability 
as  nerves  or  muscles  which  are  supplied  b\"  nerves.  Hurdon  Sanderson's 
observation  that  curarized  muscles  obey  the  same  laws  of  elect  ru- 
st inmlat  ion  as  nerves  confirms  this  fact.  Hoorweg  considers  \Yeis.~'s 
law  of  electric  excitability  to  be  true  only  of  short  discharges  and  that 
it  is  in  this  case  deducible  from  Hoorweu's  law.  lie  thinks  YYciss's 
law  leads  to  error  when  applied  to  currents  of  considerable  duration, 
while  its  simplicity  makes  it  very  useful  for  cm-rents  of  short  duration. 
Lapicque's  correction  for  currents  of  short  duration  seems  unsatis- 
factory to  Hoonveg,  because  it  assumes  an  absolute  constancv  of 
resistance. 

Tonus  Rhythms  in  Normal  Human  Muscles. — T.  A.  Storey3 
provoked  a  series  of  contraction  in  the  abductor  indicis  by  a  magneto- 
electric  apparatus,  and  made  tracings  which  showed  the  presence  of 
tonic  contractions  analogous  to  those  demonstrated  by  Joteyko  in 
verat rinized  frogs'  muscles.  The  same  experiment  upon  a  cat  whose 
sciatic  nerve  had  been  divided  showed  that  the  tonic  contraction  was 
of  peripheral  origin. 

Apparent  Inhibition  of  Muscular  Contraction. — The  experiments 
of  a  number  of  different  observers,  including  F.  H.  Hoffman,4  show  that 
there  are  no  inhibitory  nerves  to  the  voluntary  muscles. 

Contraction  of  Degenerated  Muscles  When  Stimulated  by 
Electricity. — G.  Gucrhii*  has  experimented  upon  frogs.  Normally, 
a  series  of  identical  stimuli  at  sufficient  intervals  of  time  produce  con- 
tractions of  about  the  same  form  and  height,  but  in  the  case  of 
degenerated  muscles  the  contractions  arc  unequal,  their  excitability 
varying  within  wide  limits.  Normal  muscles  are  more  excitable; 
degenerated  muscles  present  the  opposite  condition.  Finally,  in 
degenerated  muscles  great  frequency  of  stimulation  gives  a  greater 
contraction  at  the  cessation  of  the  currents  than  at  the  beginning 
(opening  contraction  is  greater  than  closure  contraction1). 

Drug  Effects  which  Simulate  those  of  Electricity. — The  clonic 
and  fascicular  muscular  contractions  which  are  produced  by  elec- 
tric stimulation  of  the  motor  nerve-trunks  may  be  very  closely  imi- 
tated when  certain  drugs  are  administered.  Hexamin-eobalt  chlorid 
given  to  frogs,  even  in  very  small  non-toxic  doses,  produces  this 
effect.1'' 

I)u  Bois-Revmond  noted  that  the  centra 

a  neii'a 


P.  \l.  dc  Hiol.,    58,  :;i4.  February  It'-.  li»0.">.aiicl  < '.  1 

February  •_>(>.  mo."). 

Arch,  f.'il.  gos.  I'liysinl..  in:;,  \\:],  mm. 

Jour,  of  I'hyM.ilony.  12.  7.">.  I'.to-l. 

Binlnmx'hrs  (Vnt  Hill  >l;i  M  .    lOo.   _",M.    I'.MIl. 

\.«  Sprriim'ntalc.  ">'.».  1^7.  1 '.»>."). 

.!.  Mock.  Arch.  1'.  rxp.  Path.  u.  PJhurmacol..  :•!<>.  1H04. 


346  MKDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

Return   of   Excitability   After   Peripheral   Nerve   Transplantation. 

— Peterson1-  reports  a  case  of  accidental  division  of  the  median  and 
ulnar  nerves.  The  condition  five  months  later  was  one  of  trophic 
di-turbance  in  the  tinkers,  anesthesia,  eontracture  and  atrophy  of  the 
muscles  of  the  thenar  and  hypothenar  eminences,  with  reaction  of 
de<:eneration.  The  end<  of  the  nerves  were  sutured,  interposing 
I  cm.  of  a  do^'s  -ciatic  nei've.  Sensation  returned  in  the  thumb  in 
twenty-four  hours,  in  the  palm  in  eight  days,  and  progressively  over 
the  hand  in  tweiitv-one  day.-,  and  the  trophic  ulcers  healed.  Motor 
:  returned  iii  two  months.  There  have  been  more  than  a 
score  of  such  cases,  and  Peterson  states  that  regeneration  is  due  to  the 
prolongation  of  axis-cylinders  trom  the  central  into  the  peripheral 
:  i  irt  \<  >n.  Setisal  ion  return-  first . 

Absence  of  Inhibitory  Nerves  in  Voluntary  Muscles.— There 
are  probably  no  inhibitory  nerves  to  the  skeletal  muscles — the  ordinary 
voluntary  muscles.  The  reduced  response  to  successive  stimuli  is 
not  due  to  the  -timulation  of  an  inhibitory  nerve,  but  is  a  phenomenon 
ol  •  ;i-j  ie.  This  i-  made  up  very  slightly  of  a  reduction  in  the  con- 
ductivity of  the  nerve,  and  chiefly  of  a  diminished  functional  capacity 
muscular  libers  and  a  diminished  excitability  of  the  terminations 
nerve,  and  of  the  muscular  fibers  i  in  mediately  after  each  stimula- 
tion. Later  there  is  a  ret u I'D  to  the  normal,  but  this  takes  place  the 
more  -lowly  the  greater  has  been  the  fatigue. ? 

Speed  and  Duration  of  Nervous  Stimulation. — The  speed  of  propa- 
gation of  a  nervous  impulse  after  unipolar  stimulation  is  about  26:43 
meter-  a  sect  nu  1. 

The  -limulation  produced  in  the  nerve  is  an  oscillatory  condition 
la-t  mir  abi  nit  '  U  K 1 1  :|  |  sen  >nd. 

Excitability  of  a  Nerve  at  Different  Parts  of  its  Length. — Budge 

and  !':!;_>•:   have  noted  a  diminution  of  electric  excitability  toward  the 

peripln-n    in   motor  nerves,  but.  according  to  Munk  and  Schultz,  this 

in:  \    have  been  ijue  to  iraumatic  changes.      I.    Munk  and   H.  Schultz8 

have    arrived    at    the   conclusion    that    the   excitability    of   the   phrenic 

'he   >ame   throughout    its  entire  course.      This  implies  that  the 

'•  ner\  His  impulse  does  not  consume  any  sensible  amount 

ol   en  i   ••_•..     uni    hence  does  not    produce  appreciable  fat  iglle. 

iiofT*  found   thai    the  excitabililv  of  a  frog's  sciatic  nerve  is 
top  iii  bottom  for  abrupt  electric  stimuli,  but  it  is  twice 
as  Lr:'''at   above  a-  below  for  Lrradually  increasing  stimuli. 

REFLEX   STIMULATION  BY  F.LECTRICITY 

(i.  A.  Pai'i  lias  .-tudied  the  relation  between  the  intensity  of  the 
stimulation  and  t  he  hei<:ht  of  the  refill tinu  contraction.  (  lenerally.  the 
stronire]  •••  •  •  ilat  ion  oi  a  centripetal  nerve  is,  t  la1  greater  number  of 
mu-cle-.  re-pond  reflexly  .and  the  stronger  i-  their  re.-ponse. 

na-  -tudied  the  fatiguability  of  the  reflex  apparatus 

\i:  •  :        '     -I     .::..]    M.-iljf-M]   Sciciiri'-,    April.    Is'.i'.t. 

I      i'    ll"!"ii;  ID,  Arch,  i    •!.  HCMHII.  l'h\ -.-idld^ic.  vol.  mi.  p.  -J'.ll,  !!>()-}. 

''   •-'    '  '•  !'.  <'.!!.  Ani'i    >ii •->(•..  c\\\ an,   1  ii'.».  .hine  1  ti    Is'j'J 

:.-    .Inly  ',',,  \^W. 
•  Ar  li    •  :   i'!.'.  -  -i!..  js],  1  ^'.^ 

Vri'i,    •     ;    .•       ['!,%  MM!  .  |x\vii.  l.'iii.  ]  s'.i'.i. 
7  An-li    I  •  :•. i    U'    I'.ii  <i  .   J'_'.  lO'.t.  1','d  i. 
'  '   •  -  "•  iHil.  :     l'i .-.  -ml.,   i:;.    1.  April   1,   iv.c.i. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  347 

in  the  spinal  cord.  The  weakest  faradic  current  which  will  produce 
reflex  contraction  in  a  frog'  becomes  ineffective  if  continued  for  a  minute 
and  a  half.  It  becomes  effecti\e  again  after  a  few  minutes'  rest,  even 
if  reflex  excitability  has  been  suspended  during  twenty  hours  continued 
faradization. 

Negative  Variation  from  Reflex  Stimulation. — Keflex  ner\e 
activity  is  accompanied  by  the  electric  phenomenon  of  negative  varia- 
tion. J.  Bernstein1  has  experimented  upon  this  subject,  stimulating 
one  branch  of  the  sacral  plexus,  while  making  electro-metric  measure- 
ments of  another  branch.  There  is  a  strong  reflex  electric  reaction 
which  is  propagated  from  a  sensory  nerve  to  a  motor  nerve,  but  not 
fro-m  a  motor  to  a  sensory  nerve.  Stimulation  of  the  posterior  root  of 
a  spinal  nerve  produces  a  negative  variation  in  the  anterior  root,  but 
stimulation  of  the  anterior  root  does  not  produce  a  negative  variation 
in  the  posterior  root.  Since  the  negative  variation  travels  through 
sensory  or  motor  nerves  in  either  the  physiologic  or  the  contrary  direc- 
tion, the  conclusion  is  drawn  that  it  is  in  the  dendritic  ramifications  that 
the  restriction  of  the  reflex  electric  propagation  to  the  physiologic 
direction  takes  place. 

The  latent  period  of  reflexes  is  best  shown  by  the  time  required  for 
the  appearance  of  an  electric  current  after  the  patellar  tendon,  for 
instance,  has  been  struck.  Paul  Hoffmann-  finds  that  this  is  normally 
about  0.019  second. 

No  Reflex  Tetanus. — S.  Baglionr  finds  that  the  cord  cannot  respond 
to  repeated  stimulation  of  a  sensory  nerve  by  the  production  of  reflex 
tetanus.  This  is  true  in  the  frog,  even  when  the  motor  excitability  has 
been  heightened  by  the  injection  of  phenol.  And  as  the  direct  stimula- 
tion of  the  motor  elements  may  cause  tetanus,  the  difference  is  solely  in 
the  sensory  cells  of  the  cord,  which  have  a  long  refractory  period  of  one- 
fourth  or  one-half  second.  Sufficiently  spaced  stimulation  of  the  proxi- 
mal end  of  the  sciatic  nerve1  in  a  phenolized  frog  produces  reflex  con- 
tractions, but  if  the  rapidity  of  the  stimuli  is  increased,  irregular  clonic 
reflex  contractions  may  ensue,  or  then1  may  be  simply  an  initial  con- 
traction, followed  by  a  passive  condition. 

Reflex  Elongation  of  Muscles. — ( 1.  A.  Pari1  stimulated  the  peripheral 
end  of  the  sciatic  nerve  in  a  recently  decapitated  winter  frog,  and  pro- 
duced elongation  of  the  gastrocnenhus  muscle  in  the  other  leg.  This 
was  generally  observed  with  weak  currents.  Successive  stimuli  of  the 
same  strength  sometimes  cause  reflex  elongation  and  sometimes  reflex 
contraction.  This  is  connected  with  oscillations  in  the  reflex  excita- 
bility of  the  cord. 

( '.  S.  Sherington  and  S.  ('.  Sowtoir'  show  by  experiments  upon  adecer- 
ebrate  or  "spinal"  dog  or  cat  that  increasing  the  galvanic  or  faradic 
current  applied  to  a  centripetal  or  afferent  nerve  produces  not  a  reflex 
contraction,  but,  on  the  contrary,  a  relaxation  of  the  muscles  at  the 
other  extremity  of  the  reflex  arc.  The  same  relaxation  ensues  when 
weak  galvanization  is  changed  to  weak  faradization.  The  same1  experi- 
menters show"  that  just  as  chloroform  reverses  the  pressor  reflex  effect  of 

1  Arch.  f.  (1.  RPS,  Physiol.,  73,  :'.7l,  isofl. 

2  Arrhiv.  fiir  I'hysioluiuo,  '2'2'.},  1910. 

3  Ibid..  4.  llo.  1904. 

4 /fir.  f.  Allge.  Physiol.,  1.  1:27.  1901. 

5Xcit.  1'i'ir  alkomi'inr  Physiologic.,  xii,  4s4  1911. 

6  Journal  of  Phvsiolosiv.   1911.  xlii.  :!K 


MEDICAL    ELECTRICITY    AND    RONTC.EN    RAY'S 

stimulation  of  an  afferent  nerve,  so  chloroform  makes  the  reflex  an  inhibi- 
tor one  and  -trychnin  a  motor  one. 

Stimulation  of  Antagonistic  Muscles.— (i.  A.  Pari   and   A.  Farini1 

have    made   experiments    with    electric    stimulation,    and    they    publish 

mvoLiTaphic  charts  uhieh  -how  thai  there  is  a  certain  physiologic  unity 

bet  wet  n    the   motor   nerves    uohm    to   a     muscle   and     it-    antagonist. 

;cles  are  I  he  <rast  rociieiniiis  and  t  he  anterior  muscles  of  t  he  leg. 

ilation    of    a    nerve-center    which    causes    contraction    of    a    given 

mu-cle  causes  simultaneous  relaxation  of  its  opposing  muscle. 

l.ii.n  A-'1.'-:'-'  has  made  further  studies  upon  antagonistic  nerves, 
u-ii  _  electricity  in  some  case-  as  the  means  of  stimulating  the  nerve- 

Ce]    '  e]>. 

Sensory  and  Other  Effects  from  Stimulation  of  the  Cervical 
Sympathetic.  Ch.  A.  Francnis-Franck8  has  made  experiments  which 

.  to  t  he  foil'  wiim'  ci  inclusions: 

1.   Stimulation  .>t'  the  cephalic  segment  of  the  cervical  sympathetic 

an —   vasoinotor  and  cardiac  stimulation   (increase  in  blood-pres.sure 

mre    rapid    heart    action).      Hurt  hie    attributed    this    to    cerebral 

.  ju-t   as  in  the  ease  of   compression    of    the  carotid   artery,   but. 

Fi    :.•;  >i.-  I  :;!.<•;.  says  thai   si  imulat  ion  of  this  part   of  the  sympathetic 

-  '•  n  tin  es  causes  the  opposite  effect  of  vasodilatation  and  slowing  of 

•  e  lie   rt '-  action :  and  that  in  either  case  it  is  due  to  a  reflex  effect  from 
centripetal  impul-es  carried  by  the  sympathetic  'to  the  cardiovascular 

enter-  in  4iie  medulla,  and  not  to  a  direct  stimulation  of  cerebral  vaso- 
coti-t  rictors,   \\ith   accompanying  cerebral   anemia. 

The  circulatory  effect   is  the  same  a-  that   produced  by  stimulation 
>i    the  anterior  crural   nerve,  but    it    require.--  a   much  stronger  current 
n  the  latter. 

_'.  <  ieneral  circulatory  changes  are  produced  by  stimulation  of  the 
medullary  segment  of  the  vertebral  nerve,  the  deep  division  of  the 
•i  v.<-::!  sympathetic,  and  these  also  are  of  reflex  oriu'in. 

•  1.    1  hi-    transmi--ion    of   centripetal    impulses    from    the   lungs   and 

ii:     b;     the   sympathetic    nerve   causes    it    to    be   a    necessary 

1     ii     'he   n  '"'  \   regulation  of  the  circulatory   functions.     This  is  a 

iiM    indication  to  the  remo\-.al  cf  the  cervical  sympathetic,  as  soine- 

".'-    '  'i    tor   the   treatment    of  exophthalmic   goiter,   epilepsy, 

a,    ''ii    the    theory    that    its    functions    were    purelv 


"''•'  mav,  therefore,  be  either  /in  ^.^m'  or  >li  f>r<  xsor, 
re-pii'al  ory,  general  motor.  pupillar\',  and  secretorv 

n  i  e  c  a .-  e  - . 

ei  •  •  '  i  imulat  ion  of  t  he  -ympat  het  ic  pi'i  uluces 
ulteii  t  he  effeci  i.-  a  ]  ii'es.-i  >r  one,  and  then 
Mil  ;  ra  |  in  1  i  >r  normal. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  34! » 

may  change  in  rhythm,  frequency,  or  fulness.  There  is 
sometimes  a  reHex  spasm  of  the  bronchi  and  pulmonarv  vessels.  This 
reflex,  through  stimulation  of  the  sympathetic,  may  explain  the  dyspnea 
which  occurs  in  some  morbid  conditions  of  the  aorta. 

The  opposite  pupil  may  be  dilated. 

The  finders  may  perspire. 

There  is  increased  secretion  of  xalira. 

As  a  final  experiment.  Francois-Franc  k  cut  all  the  filaments 
anastomosing  with  the  cervical,  hypoglassal,  spinal,  glossophaiyngeal, 
pneumogastric,  and  trigeminal  nerves,  but  left  the  anastomoses  with 
the  carotid  plexus.  Stimulation  of  the  sympathetic  then  produced 
vasomotor  effects  without  the  other  reflex  effects. 

Circulator i/  Change*  from  Stimulation  of  the  Peripheral  End  of  (fit 
Cervieal  Sympathetic. — E.  Wertheimcr  and  L.  Lepage1  exposed  the 


Fit;.  257. —Circulatory  effect  from  stimulation  of  the  peripheral  end  of  the  divided 
sympathetic'.  11,  respiration;  P,  pulse;  E,  electrical  stimulation  (Wertheimer  and 
Lepage). 

inferior  and  the  first  thoracic  or  stellate  ganglion.  Following  the  cuttinu 
of  the  sympathetic  nerve  above  this  point,  there  is  an  irregularity  of 
cardiac  rhythm,  and  this  same  irregularity  is  found  when  the  peripheral 
end  of  the  divided  sympathetic  is  stimulated,  and  also  when  the  intact 
sympathetic  is  stimulated.  The  latter  is  not  so  desirable  for  this 
experiment,  because  it  produces  sensory  symptoms  and  requires  an 
anesthetic. 

Ejject  Upon  the  Pupil  from  Stimulation  of  the  Sympathetic. — Lowan- 
dowsky-  lias  experimented  upon  both  warm-  and  cold-blooded  animals. 
He  finds  that  in  the  former,  stimulation  of  the  nerve  above  or  below 
the  superior  cervical  ganglion  causes  a  contraction  lasting  five  to  ten 
seconds,  while  in  cold-blooded  animals  it  lasts  very  much  longer.  The 
muscles  controlling  the  sixe  of  the  pupil  are  non-striated.  The  duration 
of  contraction  is  in  direct  proportion  to  the  strength  of  the  current. 
The  make  discharge  from  an  induction  coil  either  gives  no  contractions 
or  only  short  weak  ones.  The  opening  discharge  gives  very  much 
stronger  contractions.  The  myographic  curve  shows  an  abrupt  ascent 
and  a  much  slower  descent. 

Vasomotor  Effects  on  the  Small  Intestine  Produced  by  Stimu- 
lation of  the  Central  End  of  the  Pneumogastric. : — Stimulation  of 
the  central  end  of  the  vagus  in  dogs  produce^,  in  some  cases,  dilatation 

1  .lour.  <le  Physiol.  rt  do  P.-ithol..  is«)<t.  p.  2.:;s. 
-  Arch,  dt"  Physiol.,  1S«)D.  :}.Y_'. 

3J.    L.    Hunch,    Proceeding  of   the   Pliysiolou-icul   Society.   .Journal   of   IMiv<ii>l 
1S'M>.  L't. 


350  MKDKAL    ELKCTKICITV    AND    KONTGEN    RAYS 

or  constriction  of  tin-  intestinal  blood-vessels.  In  cither  case  there  is 
an  increase  in  tllt.  oyneral  blood-pressure.  hut  the  vasodilatation  may 
he  obtained  even  when  the  blood-pressure  is  maintained  at  a  constant 
level  !>y  hydrostatic  means.  It'  the  splanchnic  nerves  are  cut,  stimula- 
tion of  the  central  end  of  the  vagus  is  not  followed  by  vasodilatation  of 
the  intestine. 

In  a  cat.  stimulation  ef  the  vagus  always  causes  dilatation  of  the 
in'e-tinal  vessels,  accompanied  by  a  fail  in  the  general  blood-pressure. 

Stimulation  of  the  Pneumogastric  and  its  Motor  Effect  on  the 
Small  Intestine.  1).  Courtade  and  .1.  F.  Cyon1  find  that  strong  stimu- 
lation of  the  pneumogast  ric  nerve  in  the  thorax  produces  a  contraction 
of  the  longitudinal  muscular  fibers  which  is  followed  by  their  relaxation, 
:ind  later  by  a  contraction  of  the  circular  fibers.  This  contraction 
;'"'•  --  in  character  of  progress  and  in  rapidity  from  the  effect  produced 
':>•.  st  imulat  ion  of  T  he  sympat  het  ic. 

.1.  !..  IV;nch2  obtains  the  same  results  by  stimulating  the  pneumo- 
L'a-'  ric  in  the  neck. 

Reflex  Vasodilatation  from  Stimulation  of  the  Sciatic  Nerve.  — 
I.  X.  !'v-t  renini'3  made  experiments  on  cats  and  dogs.  He  found  that 
electri/ation  <>f  the  sciatic  nerve  by  a  current  of  medium  intensity  is 
foll<,wi'd  bv  vasoconstriction,  while  weaker  or  stronger  currents  produce 
vasodilatation. 

Stimulation  of  the  peripheral  end  of  the  sympathetic,  at  the  level 
ij  the  fifth  or  sixth  lumbar  vertebra,  does  not  produce  vasodilator 
effects,  contrary  to  the  opinion  of  Ostrooinov. 

Motor  Effects  Upon  the  Stomach  from  Stimulation  of  Different 
Nerves.  -I).  Courtade  and  J.  F.  Cyon4  find  that: 

1.  Stimulation  of  the  intact  pneumogast  ric.  or  of  its  peripheral 
end  ii  it  i-  divided,  causes  contraction  of  the  longitudinal  fibers,  then  of 


'  '  .  '  •  circular  fibers,  and  t  hen  a  per  KM!  of  rest  .  There  mav  be  a  relaxation 
"'  '.'.••  circular  libers  at  the  cardia  and  pylorus,  simultaneously  with  the 
c  >nT  r;ict  ion  ol  t  he  longitudinal  fibers. 

•    Stimulation  oi  the  peripheral  end  of  the  great  splanchnic  arrests 

at   the  same  tune  caii.-e.-  tonic  contraction  of  the  circular 
';b>-rs.  .-;.•  .•    the  cardia  and  pylorus,  and  also  relaxation  of  the 

..  :-. 


I'.'Ji'f  "<  It'll  f-.li  ctr/ztit/iin  <>f  Hi  Stninncfi  I  /mn  itx  Secretory  Activity. 
\\  .  !•  reund    find-  t  ha  t  t  hi-  doe-  not  effect  t  he  secret  ion  of  gastric  juice, 
-  a  moderately  increased  mucous  secretion,  which  is  more 
,  ,r  If--,  -t  p  .nu!v  alkaline. 

Effect  of  Direct   Stimulation  of  the  Heart.     KjJ<cl  <>f  Intracnrdiac 

I.'  I'1    I'urreni  from  two  ordinary  voltaic  cells  and  the  extra 

nl    ti'om  a  -mall  electromagnet,  ]»a--ing  between  electrodes  placed 

(      !.'..-•    •:•    I'.IM!..  tent),  -.TIC-,  ii,  •_':,.  .I.-uiuitry,  Is'.i!*. 
.!•  vXV.  L'2.   IMW. 

'    N-   '-         \--ll   irk.    1'J.    L'^J. 

ill.  •  t   ,1,    ['ntli.il    Ccn..    1.".   IVKi. 
'  Ar-  !:    i     Pit!      \!i  ,t    \i.  I'hv-inl..   ]MI.  i';;s.  Ktn.",. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  351 

inside  the  ventricle  of  a  horse's  heart,  has  caused  almost  instantaneous 
death.  This  happened  in  an  experiment  by  A.  Chauveau,1  who  was 
studying  the  movements  of  the  valves  of  the  heart.  A  thin  insulated 
stem  was  passed  through  the  carotid  artery,  aorta,  and  aortic  valves. 
It  contained  a  spring  which  closed  an  electric  circuit  when  pressed  upon 
by  the  contracting  valves.  This  current  actuated  a  small  electromag- 
netic signal,  an  extra  or  self-induction  current  from  the.  coils  of  this 
passed  through  the  blood  in  the  ventricle,  when  the  aortic  valves  opened 
and  allowed  the  contact  to  be  broken.  This  occurred  at  each  pulsation 
of  the  heart,  which  was  tremendously  accelerated,  and  the  animal  died 
almost  immediately.  The  currents  were  so  weak  that  they  could  not 
be  felt  when  the  tip  of  the  tongue  was  applied  to  the  point  where  the 
contact  was  made  and  broken.  The  fatal  effect  upon  the  heart  was 
prevented  in  further  experiments  by  establishing  a  short  circuit  for  the 
extra  current  at  each  make  and  break. 

Effect  of  Induced  Currents. — Tetanic  contraction  was  produced  in 
Danilewsky's  experiments  upon  different  warm-blooded  animals.2  A 
living  rabbit's  heart  was  isolated  by  Langendorff's  method,  and  hot 
Ringer's  solution  saturated  with  oxygen  circulated  through  its 
coronary  arteries.  It  had  its  apex  in  contact  with  two  electrodes 
from  an  induction  coil,  giving  currents  perceptible  to  the  moistened 
finger.  The  heart  was  in  a  condition  of  lessened  vitality  and  extremely 
sensitive  to  currents  from  an  induction  coil  or  from  a  magneto-electric 
machine.  Weak  or  medium  currents  produce  a  tetanic  contraction  of 
the  ventricles,  while  the  rhythmic  contraction  of  the  auricles  continues. 
This  contraction  may  be  maintained  for  two  and  a  half  minutes,  and  is 
followed  by  a  pause  succeeded  by  a  very  ample  systole.  Stronger  or 
more  frequently  interrupted  currents  do  not  produce  as  vigorous  con- 
traction or  as  complete  tetanus.  It  is  extremely  difficult  to  produce 
tetanus  of  the  heart  with  the  latter  in  xitii  and  uninjured.  It  may  be 
obtained,  however,  when  the  refractor}'  period  (or  latent  period  of 
muscular  contraction  from  electric  stimulation)  is  diminished  by 
poisons  or  pathologic  changes,  or  when  there  is  hyperexc  it  ability  or 
hypodynqmia. 

A.  Bohme's  experiments11  upon  a  frog's  heart  whose  electric  excita- 
bility has  been  destroyed  by  chloral  poisoning  show  that  it  is  restored 
by  camphor. 

Experiments  by  Fran/  Mil  Her4  show  that,  in  human  beings  suffering 
from  tetanus  or  lock-jaw,  there  is  no  electric  hyperexcitability  of  the 
heart.  This  organ  differs  from  the  striated  muscles,  such  as  the  dia- 
phragm, in  this  regard. 

V.  Duchesi's  experiments'"'  upon  a  frog's  heart  slowly  poisoned  by 
phosphorus  show  that  electric  excitability  diminishes  very  rapidly,  as 
well  as  the  height  of  the  contraction  produced  by  electric  stimulation. 

The  heart  may  be  made  to  pulsate  by  direct  electric  stimulation, 
even  while  it  is  in  a  state  of  arrest  from  electric  tetanization  of  the 
pneuinogastric  nerve.  M.  Stasser"  performed  an  experiment  upon 

1  Journal  <lc  Physiologic  ct  <lc  Biologic.  3X1,  1X00. 
-  Biolo-risdics  Centralblatt,  fix,  .">%.  lOOo. 
3. Journal  <!<•  I'hysiol.  ct  <le  I'athol..  lOOo. 

4  Dcutsch.  Arch',  f.  klin.  Mc<l.,  111.  1)32. 

5  Arch.  ital.  .lc  Jiiol.,  xxxi,  23  2.  1x07. 

6  Arch,  intcrnat.  dc  Physiologic,  2,  2f>9,  1005. 


;}.Y2  MKD1CAL    ELECTRICITY    AND    RONTGEN    RAYS 

,!,,_,•  ;in,l  rabbits'  heart-,  one  electrode  on  an  auricle  and  the  other  on 

the    correspond  iim    ventricle.      An    isolated    induction    shock    causes    a 

svst  -lie  contraction  orrurrimr  simultaneously  in  hot  h.  but  preceded  by 

:l'  ;.;-,:,•    ,,;•   refractory    period   of  ii.Uii  second.     The  same  stimulation 

both  electrodes  applied  to  the  aui'icle  causes  an  auricular  pulsation 

:,  latent    period  of  n.mi  second,  and  this  is  often,  but   not  always, 

,vd   n. us  ',,[•  11. TJ   second  later  by  a  ventricular  contraction.     Ap- 

-tiniiilus  to  the  ventricle   it    takes  three  times  as  long  for  the 

sub*  .  iar  ci  nit  ract  \>  >\\  to  occur. 

T.  Philips1  has  made  an  experimental  study  of  the  fibrillary  tremors 

pi     ;  .  .,,j  ;n  tin    heart   by  electricity.      Ib'  found  that   fibrillation  of  the 

irides  produced  by  direct   stimulation  does  not   arrest   the  ventricles, 

i,  ,•    ^ives   them    a   disordered    rhythm    (Kronecker   and   Spalita   do   not 

-_;•••••   v.  ;•':,   this  statement).       He  found  that   as  soon  as  the  auricular 

<:,•.,,;•  Drives  place  to  regular  contraction   the  normal  ventricular  rhythm 

i- resumed.     Stimulation  of  the  pneumoiiastric  prevents  the  occurrence 

Iar  librillat  ion  from  electric  stimuli  (this  contradict?  Kronecker 

and   Spalita).   and   also   the  disturbing  effect    of  auricular  stimulation 

vein  rides. 

M'i'<!    stitn  illation    <>f  tin     /i)t<  a  moijasfric    itihihit*    the    ( tnct    of  direct 
.•'--   ,    ifiiitt  t>t'tln   i'i/i/i.  iinil  c<ut*i*  tin   n  nii'ii'li  N  to  ri  tn/-)i  in  tfun'  normal 

/'..    .  -ful   xtirtnilnlinn   of  tin    pncnningaxtric  arri-xt*  the  pulsations  of 
•• .   •.,,-'. 

]•'..  Ib-don  and  T.  Arrows2  have  experimented  with  electric  stimula- 
tion of  the  isolated  myocardium  or  the  muscular  substance  of  the  heart 
in  a  liviiiii  rabbi;.  The  effect  is  to  relax  the  muscular  fibers  and  to  pn>- 
loim  the  ensiiim:  diastole.  The  same  effect  is  produced  by  stimulation 
oi  a  heart  poi-on.-d  b\'  ati'opm.  Severe  n  icoi  in-poisonint£  in  a  doir 
-e-  the  electric  excitability  of  the  heart  and  makes  it  more  per- 
->•'•:.'. 

/,'.-''.;•  t'urdiiir  Slim  >i}<i/i<>it  ux  Moilit'nd  li>t  Cirtnin  I 'o  i  *o  n  * . — Under 

':  >rmal  conditions,  stimulation  of  mo-t  of  the  sensory  nerves  leads  to  a 

.:     :•;:->•    ;u   cardiac   enersry.      Thi-   can    be   accurately   measured 

•  •   increase   m   the  bloo(l-]>ressiire   m   the   arteries  and   its 

r>  d'icT ;  ,n  ;n  tin-  left  auricle.      ]•'.  \V  inkier*  ha-  foiiml  that  while  st  imula- 

'    ''     >:   '  '  .-•  •  erve  in  a  healt  hy  animal  increases  the  \\-i  »rk  done  by 

•      '    li     -.''l   per  cent.,  'here  was  an  increase  of  only   1  \(\  per  cent. 

•!  poj-oiicd  by  muscarin  ftoad-stool  poisoiO.    Sodium 

'.  '     '•  'in  •     n-duce-;  the    reflex    cardiac   stimulation,  or    it    may 

evi'ii    r--  .  •     n     •    re(lc\    reduction   ot   cardiac   ar-tivity   \\ln-n   the  sciatic 

•     i-   -ti::.u     '••;.        \nd    under   the   influenre  of  am\'l   nitrite  electric 

stimulation  produces  a  reflex  enfeeblement  of   }.">  to  7">  per  cent,  in  the 

It    doc's    not    slow   the    tachycardia   of   amyl   nitrite. 

-lo\v  the  normal  puUe;  and  it   increases  the  tachycardia 

nit  nt e  and  increa-e-  t  lie  rapidity  of  t  he  ext remelv  slow-beating 

1 1  -  o  1 1 1 1  m . 

Electric  Stimulation  of  a  Nerve-center,  or  of  the  Spinal  Cord,  or  of 
a  Nerve.       I  I  the  function  of  the  part    stimulated,  and  a  mus- 

1  ular  [iiovenn  i  en-ation  or  -nine  other  effect   i-  produced. 


PHYSIOLOGIC    EFFECTS    OF    ELECTRICITY  353 

Applied  to  different  parts  of  the  cortex  of  the  brain,  it  has  given  us 
the  most  valuable  and  minute  localization  of  brain  function,  and  applied 
to  the  different  other  parts  of  the  cerebrospinal  and  sympathetic  nervous 
systems,  it  has  decided  many  problems  as  to  function  which  were  not 
to  be  determined  by  experimental  physiology  without  the  use  of  elec- 
tricity. 

The  varying  physiologic  effects  have  a  direct  bearing  upon  the 
therapeutic  use  of  electricity. 

Stimulation  of  the  olfactory  centers  in  the  brain  causes  the  same 
disturbance  of  respiration  that  is  produced  by  the  inhalation  of  ammonia 
and  similar  substances.  Dyspnea  may  continue  even  after  the  stimu- 
lation has  ceased.1 

Electric  Stimulation  of  the  Optic  Nerve  does  not  Produce  the 
Sensation  of  Light. — This  is  the  surprising  result  of  a  series  of  operations 
upon  six  different  human  patients  in  whom  the  optic  nerve  was  laid 
bare  as  the  result  of  operations  or  injuries  and  subjected  to  electric 
stimulation.  Other  stimuli,  chemical  or  mechanical,  gave  the  same 
result.2 

Electric  sensation  is  quite  distinct  from  that  of  pressure  or  heat, 
etc.  A  tuning-fork  may  be  used  to  produce  vibratory  pressure  and  at 
the  same  time  to  transmit  to  the  skin  a  faradic  current  for  which  the 
tuning-fork  acts  as  the  primary  interrupter.  The  patient  should  be 
able  to  tell  the  difference  between  the  pressure  of  the  tuning-fork  alone 
and  when  the  electric  current  is  added.  Arrigo  Tamburini  has  con- 
structed an  apparatus,  called  the  polycesthesioscope,  by  means  of  which 
sensations  of  warmth,  vibration,  pin-prick,  and  electricity  may  be  tested 
separately  or  together.15 

»y.  Duchesehi,  Archive  Ital.  do  Biol.,  lii,  1S3,  1910. 

-  S.  Culdero,  Archive  di  farmacologia  sperimentale  et  scienze  affini.  x,  11,  1910. 
;  Rivi.sta  sperimentali  di  Freniatri  e   Medicina  legale  delle  alienazioni  mentali, 
xxxvi.  977,  1910. 


ELECTROPATHOLOGY 

'I'm:  harmful  effects  of  elect  nViiy  upon  the  human  body  have 
been  observed  in  cast's  »t"  lightning-stroke,  accidents  from  contact 
with  conductors  charired  with  high-tension  electricity,  and  undesirable 
effect-;  from  therapeutic  application  of  electricity.  Manx"  experiments 
have  been  made  upon  animals,  and  have  given  us  an  exact  knowledge, 
of  the  danger-  and  of  the  mean.-  required  to  make  safe  use  of  this 
invaluable  anencv. 

The  effect-  may  tie  anatomic  or  functional,  general  or  local,  and 
may  be  immediate  or  may  not  develop  until  later.  The  maximum 
effect  i-  death. 

Lightning-stroke.  The  mechanically  dest  ruct  ive  results  seen  when 
a  tree  i-  -truck  bv  liirht ning  are  thought  to  be  due  to  the  sudden  explo- 
-ive  e\  pan -ion  of  trases.  These  are  generated  partly  by  simple  vaporiza- 
t  ion  from  heat  inu  of  t  he  fluids  in  t  he  pores  of  t  he  vvood.  and  parti}'  by  the 
electrolytic  decomposition  of  these  fluids.  A  man  struck  by  lightning 
i-  not  tom  into  piece.-,  but  the  same  disruptive  effect  may  occur  and 
produce  iri'MS.-  or  microscopic  changes.  The  gross  changes  occur  as 
area-  of  de-tructive  extravasation  in  different  organs,  and  upon  the 
surface  at  the  place-  where  the  electric  discharge  entered  and  emerged 
from  the  body,  and  constitute  the  well-known  lightning  figures  which 
have  .  •  e  to  the  most  extraordinary  theories  in  the  scientific  as 
well  a-  in  the  lav  m  i  nd.  1  he  tu  ic  ro-copic  effect  s  are  of  a  cor  res  p<  Hiding 
nature. 

L'ljlif/,  *  mi  F njtirt  N.— -Markings  are  found  upon  the  surface  of  a  person 
who  ha-  been  struck  by  lightning,  and  these  often  have  a  branching 
appearance,  -u^ne-t  ive  of  the  trunk  and  limbs  of  a  tree. 

A  thirty-one-year-old  man.  -truck  by  lightning  and  thrown  to  the 
irround.  -tated  that  he  did  not  lo-e  consciousness;  could  not  move  his 


"  '    '-'''    I"1  \\'a-  -truck.     The  lightning 
"•"  <!••'>-.      The  deeper  burn-  of  the  first 

" lorinuof  the-kin.  whicli  appeared  eight 

'•Mm-  gradually  darker.      Thi-  piu-mentation 
"  '•'•''  y-'ar-  after  the  injury.      Mu.-cul;ir  weak- 


ELECTROPATHOLOGY  355 

ness  remained  for  several  weeks  and  no  internal  injury  was  evident.  A 
year  later  he  could  work  very  well,  although  the  left  leg  was  weaker,  and 
before  each  thunder  shower  he  felt  pain  in  both  legs  and  in  the  lumbar 
region.  The  left  leg,  and  especially  the  top  of  the  foot,  was  slightly  bluish 
in  color  and  felt  cooler.  There  was  increased  patellar  reflex  on  the  left 
side.  Other  cases  have  occurred  in  which  a  resemblance'  to  other  objects 
has  been  noted,  and  a  man  is  now  being  exhibited  in  public  places  in 
America  whose  back  is  said  to  show  a  very  striking  picture  of  a  crucifix 
in  consequence  of  a  lightning-stroke. 

The  explanation  offered  in  Rockwell's  excellent  book  "(Medical  and 
Surgical  Electricity,"  p.  1(>0)  can  hardly  be  accepted  at  the  present 
day.  It  is  as  follows:  "The  explanation  of  all  these  cases  is  the  same. 
The  particles  of  the  tree  reduced  to  great  fineness  by  the  electricity  are 
mechanically  transported  and  burned  in  the  skin.  The  process  is, 
therefore,  not  chemic,  but  mechanic  and  thermic." 

The  utter  impossibility  of  this  explanation  lies  in  the  fact  that  it 
requires  us  to  think  that  particles  from  small  parts  of  any  individual 
branch  of  the  tree,  instead  of  flying  off  in  all  directions  into  space,  fly 
right  straight  to  a  particular  spot  the  size  of  a  pin-prick  on  the  surface 
of  the  patient's  body.  Particles  from  a  branch  four  inches  thick  and 
fifteen  feet  long  would,  accordingly,  have  to  reach  the  body  only  along 
a  narrow  line  a  few  inches  long. 

The  particles  formerly  supposed  to  be  emitted  from  the  trunk, 
branches,  -md  even  individual  leaves  would  certainly  produce  a  general 
blur,  particles  from  each  part  of  the  tree  affecting  the  whole  surface 
which  the  particles  could  reach.  There  is  no  suggestion  possible  of  a 
lens-like  action  in  this  case. 

The  correct  explanation  of  these  lightning  figures  seems  to  be  that 
they  are  anatomic  changes,  erythema  or  extravasation,  produced  by 
the  electric  discharge  applied  at  a  certain  part  and  extending  into  the 
deeper  tissues  or  following  the  superficial  tissues  along  the  lines  of  least 
resistance.  The  latter  lines  depend  partly  upon  the  place  of  exit  of  the 
discharge  and  partly  upon  the  direction  of  the  blood-channels  and  other 
paths  of  comparatively  good  conductance.  Then,  again,  the  path  of 
such  a  discharge  of  high-tension  electricity  starting  from  a  point  and 
extending  through  a  medium  which  is  not  homogeneous  has  a  natural 
tendency  to  be  radiating  and  to  branch  and  subdivide.  A  static  spark 
applied  to  a  photographic  plate  (pp.  47  and  .">())  illustrates  this  tend- 
ency in  a  beautiful  manner. 

In  some  cases  the  lightning-stroke  does  not  cause  branching  figures, 
but  simply  a  discolored  surface. 

The  surface  marks  in  a  case  of  lightning-stroke  do  not  necessarily 
correspond  with  t  he  severity  of  the  symptoms  produced.  These  depend 
upon  the  organs  which  happen  to  t'oim  the  conducting  path  between 
the  places  of  entrance  and  of  exit  for  the  discharge,  and  may  be  death, 
loss  of  consciousness,  deafness,  temporary  or  permanent  paralysis  of 
different  parts. 

Death  from  Lii/htnhifj-xtrolci .  This  is  general!)  accompanied  by 
demonstrable  lesions  in  the  central  nervous  system,  extravasations  ot 

legration.  The  person  is  usually  rendered 
without  pulse  or  respiration.  I1V  may 
>r  ma\'  respond  for  a  while  to  appropriate 


MKDK  AL     KI.F.l  THICITV     AND     KONTCIEN     HAYS 

'/'/>  nfim  nt  af  LiyhtniiKj-xtrol:*'. — As  it  is  impossible  to  say  from  the 
condition  of  the  patient  immediately  after  the  shock  whether  or  not 
there  are  irreinedialile  lesions,  an  effort  at  resuscitation  should  he  made 
in  everv  case.  \\  rapping  the  patient  in  dr\'  warm  blankets,  performing 
artificial  respiration  with  the  patient  recumbent,  and  a  certain  effort 
at  cardiac  massau'e  bv  intermittent  pressure  applied  just  below  the 
border  of  t  he  rib-  are  most  important.  Hypodermics  of  cardiac  or 
nt  her  -tiinuhtnts  may  he  ^iveti.  but  it  is  important  here,  as  in  every  case 
in  which  t  he  circulat  ion  has  practically  ceased,  not  to  give  an  overdose. 
If  one  were  to  continue  to  Lnve  repeated  injections  ot  strychnin  or 
[in  hecau-c  ii"  effect  was  noted,  so  much  miirht  be  given  that  if 
the  heart  did  -tart  up  au'ain  and  carrv  all  these  several  doses  into  the 
lation.  the  patient  mi^lit  be  poisoned.  Do  not  administer  more 
than  the  proper  total  amount  of  a  powerful  drug  in  these  cases,  even 
if  t  here  i-  no  percept  ihle  response  to  it.  The  que.-.t ion  of  the  employment 
."•.  as  a  means  of  stimulating  the  diaphragm  <>r  the  heart  mav 
he  ci  >n-iderei  1  in  individual  cases. 

The  Pathologic  Effects  of  Static  Electricity.  The  high-tension 

ciim-iit-    produced    by    the    static    electric    machine.-    have    such    small 

tity  that  the  .-hocks  they  give  if  carelessly  handled  are  incapable 

•  •    :       ,  iriiui    serious    pathologic    lesions    or   even    serious    symptoms. 

While   ti,,.  effect    of  startling  the   patient    is  undesirable,   the  muscular 

contraction  excited  bv  a  static  .-park  is   not   of  a  painful  character  and 

L-  only  momentary.      A  -ingle  static  spark  does  not  produce  any  chantre 

:'i   the  tis.-ues.   but    a   number  of  sparks  applied   to  the  same  spot   in  a 

continuou-   stream    will   produce   ai    first    a    white  swelling  of  the   skin 

from  edema  and  this   is  followed  by   redness  and  in  extreme  cases  by 

veMi-aiion  and  other  evidences  of  a  burn.      The  effect   on  the  tissues  is 

v  a  local  one,  and  is  sometimes  produced  purposely   as  a  counter- 

'  mt.      Its  accidental  product  ion  is  to  be  avoided.      For  instance,   in 

::r_r  the  wave-current  or  the  static  induced  current,  where   one  or 

h  •'•.  electrode-  a  re  fixed  in  position  upon  the  skin,  it  is  important  That 

.,d    be    a    perfect    conducting  contact.       If  there   is   a   place   at 

•    c  invnt   has  to  -park  across  to  reach  the  skin,  a  slight   burn 

>•  in  lie  produced. 

a    per-oti    -iiould    accidentally    receive   the   full   charge   of  a   static 

.'."   :>'•    touching  the  two   poles  at  the  same  time,   there  would  be  a 

•'  '  :,-•  arms  as  t  hey  were  involuntarily  drawn  awav.  but 

1      '    -•    '  :    ill-    fe-tj!t  . 

•  •      oi    i-li  ctrolysis   need   not    be   considered    in   connection 
••  pa'iio    i          fleets  of  the  very  briei    and  (jiiantitatively  small 
'  ity,  tlioiigh  it   i-  true  that   they  are  unidirec- 
iduce  a  certain  -mall  amount  of  electrolysis. 

Manner     in    Which     Electric     Accidents     Occur.     The     proverbial 

ion     i-  all  important  here.      Many  lives  mav  be  saved 

eroii-  electric  contact-,  which  very  often  cause 

m  -pite  of   the  nid-t    -kilful  treatment,  after  an 

.!<  Ilinek,   in   hi-    "Atlas  der   Klektropathologie," 

the  many   wa\>   in   which  accident-   have  actually 

ou-e  t  here  -hould  1  >e  ii o  bare  wire-  or  uncovered 

-hould   be  in  a   covered  case.      When  it   is 

h  part  of  the  electric  li^ht  circuit .  one  should 

•ee  that  he  i-  not  -  -  'j  in  a  wet  place  or  upon  metal  of  any  kind:  he 


ELECTRO PATHOLOGY 


357 


should  use  only  one  hand,  and  should  not  at  the  same  time  touch  any 
metal    or  anything   connected   with   the  electric-light   circuit.     If  one 


Fig.  259. — 220  volts  direct  current  short  circuited;  superficial  impregnation  of  the 
skin  of  the  hand  and  of  the  face  with  particles  of  metal.  The  current  should  have  been 
turned  off  before  he  began  to  do  this  work  (Jellinek). 


hand  happens  to  touch  two  oppositely  charged  surfaces  it  is  disagree- 
able, but  if  both  hands  do  so  it  is  dangerous.     And  the  same  is  true  in 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

reuard  to  touching  an  electrically  charged  surface  with  one  hand  and 
niakhm  a  ground  connection  at  the  same  time. 

in    electric    laboratories    and    power-houses    there  are  many   bare 


chan.:-rd    -airfares   and    the   currents   are   often   of   high    tension.     The 
attendant-  should,  of  course,  be  instructed  in  the  danger  of   touching 


nlt-  l>i;iih  with  ;i|ij)c;ir;iiicc  i,f  ~yih|jlfini-  of 
.-:n-t  [,;.i  i!\  -I-.  'I'lic-r.'  wa-  :i  -liu'tit  mark  lik.'  a 
i  i  v,  i  -.•  I  if  It  ml  i-ij  |  if  rffft  l.\  rial  ur.'tl.  No  ot  her 
inf'l  •'  it  tlii  cut  ui>n-  inadf  mechanically  ami 
-nr.'i  ^  .li'llnifl.i. 


ELECTROPATHOLOGY 


359 


form  of  dry  wood  covered  by  a  rubber  pad,  wherever  an  attendant  has  to 
stand  while  lubricating  or  cleaning,  or  regulating  any  part  where  there 


Fig.  2(j:5. — Alternating  current,  10,000  volts.  Death  after  taking  three  steps  for- 
ward. Burns  of  the  hack  and  the  right  arm:  no  postmortem  changes  to  he  discovered 
(Jellinek). 


MEDICAL    ELECTRICITY    AND    RONTGEN    HAYS 


near  any  live  >urface.  Of  course,  a  "live  wire"  should  not  be  touched, 
1. in  the' danger  i-  obviated  when  1  he  man  is  insulated  from  connection 
with  the  ground  or  any  metal  or  liquid. 


1  in.  _'•:.•).  --. \lirniatiim  current,  KXK)  volts.  Burns  of  the  finders  of  both  hands;  cried 
f,,r  h.-lj,.  vva-  quickly  freed  fiom  tlie  contact,  and  wa.s  able  to  walk  with  assi>tance.  The 
man  mad''  a  i:ood  recovery  ( Jellinck). 

Danger  from  Ordinary  Electric  Lights  and  Telephones. — An  electric 
lamp  or  a  telephone  should  never  be  touched  with  one  hand  while  the 


1  hi'  fiirri'iit  entered  at   tin-  forearm  and 
.      II'    remembered  the  oceiirreaae,  and 
rriit   u  ;.-  rin  (.IT  |,y  an  automatic  break, 
nd    he    v,:,-    able    to    <_'o    home 


ELECTROPATHOLOGY 


361 


within  reach  of  a  wash-stand  or  bath-tub  or  any  metal  rail  or  the  like. 
The  slightest  displacement  of  one  wire  or  the  other  in  an  electric-light 


Fig.  267. — Electric  engineer.  Alternating  current,  220  volts.  Right  hand  reddish- 
hrown  burn.  Eyes  only  saved  by  the  eye-glasses,  which  were  flecked  with  particles  of 
metal  burnt  into  them  (Jellinek). 

Docket  may  convert  the  exposed  metal  part  into  a  charged  surface,  giving 
only  a  disagreeable  shock  to  a  person  who  is  insulated,  but  dangerous 


Fit:.  2fix.   —Alternating  current,  220  volts.      Called  for  help  and  told  them  to  pull  out 


the  contact    pluiz  at    the  wall  socket.      Left-hand  fingers  all  burned.      Right  hand  showed 


no  changes  until  sixteen  ihivs  later,  then  flat  while  nrcrotic  areas.      Xo  other  svniptom.-  01 


lesions  (Jellinek). 


to   one   through    whom    a    ground    connection    takes   place.      The   same 
danger  is  liable  to  occur  from  the  telephone  if  a  telephone  and  electric 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

wire  have  become   "crossed."     Rubber  -loves  and  the  various  other 
urerautions  must  be  insisted  upon  in  all  work  upon  high-tension  wires. 


I     ,      ,    .  :    -   t-lcctric   lump   -ockd    with  one  hand  and  the  metal  fixture  with  tin 


Death  from  Electromedical  Apparatus  Actuated  by  the  Electric-light 

Current.       \  •   \\:i~  reporiei]  i<>  ihc  autlioi-  li\    I  )r.  .1.  \\illard 

I  .    ,Iilli<      17      I'.ll'.t.    ;ilid    iicrlllTcd    Ih    |)n\c|-.    N.    .1.        ,\    >tl'Oll^   yoilll}i' 

',',  I'll  i   \ci   pi    'MI    -llji'lil    11  M  liuc-t  K  ih  .  ;i  p plied 

.'.  di!i '   -'  ;itci  I  Hi  a  /,l!ie-lmei|  t  i;i  t  li  mi  >  full  of  \vat  el' 

!'•;!.  linn  1 1 ,  i  )|i  •  M  )•(  ,11  MI  |.       People  in  I  he  hou>e  heard 

thi-n  ;in  oiiierv.      TlnA1   |p]'<)kc  into  the  room 

in'.1    ;i    ''".    -li'jht    rno\  ciiicnt-   ;UM|    the   vil  iral  or 


ELECTROPATHOLOGY  •><>•> 

lying  on  his  chest  where  then;  was  a  burn.  The  tub  was  so  short  that 
even  in  his  relaxed  condition  his  head  rested  on  the  upper  edge,  not  in 
the  water.  His  friends  pulled  the  vibrator  free  from  the  alternating 
current  electric-light  socket,  receiving  a  shock  in  doing  so.  He  died 
almost  immediately.  No  other  marks  were  found  upon  his  body.  No 
fuses  blew  out  and  there  was  no  evidence  of  anything  but  the  110-volt 
alternating  electric-light  current  having  caused  his  death.  The  body 
showed  a  slight  burn  on  the  chest  about  fourth  rib  and  interspace,  red 
and  soon  became  very  dark,  the  body  was  mottled  in  appearance,  but 
showed  no  other  burns.  The  water  was  draining  out  of  the  tub,  his 
foot  having  evidently  pushed  the  plug  _out  in  an  involuntary  move- 
ment. 

His  body  was  thoroughly  grounded  by  the  large  surface  of  contact 
with  the  water  and  transmitted  a  fatal  current  from  contact  with  a 
charged  part  of  the  vibrator.  If  he  had  been  standing  in  dry  shoes 


1'iii.  271. — Man  killed  by  110-volt  alternating  current  from  vibrator   applied    while  in  a 

bath-tub. 


upon  a  dry  floor  so  little  current  would  have  been  transmitted  as  to 
have  produced  only  a  slight,  disagreeable  sensation,  or  none  at  all. 

The  Author's  Experiments  Upon  Electric  Accidents.—  Experiments 
by  the  author  have  been  with  galvanic,  faradic,  and  sinusoidal  apparatus 
actuated  by  the  electric  light  current  with  which  a  patient  ordinarily 
receives  from  the  two  terminals  a  suitable  strength  of  current  regulated 
by  a  volt  controller  and  a  rheostat.  It  may  happen  that  if  the  patient 
is  grounded  he  may  receive  from  one  terminal  the  110  volts  electric- 
light  current  unmodified  by  the  volt  controller  and  rheostat  as  it  would 
be  if  the  circuit  depended  entirely  upon  contact  with  another  terminal 
for  its  completion.  It  would  be  dangerous  to  apply  an  electrode  from 
such  an  apparatus  to  a  person  in  a  bath-tub  or  otherwise  efficiently 
grounded.  If  such  currents  are  to  be  applied  to  a  patient  in  the  bath, 
the  apparatus  should  ('specially  be  designed  to  prevent  the  patient  from 


MKDK  Al.    KI.K(  THKITY    AND    KO.NTtlKN     HAY; 


receiving  the  unmodified  elect ric-light  current  even  if  he  is  grounded. 
In  some  apparatus  this  is  accomplished  by  using  the  terminals  of  the 
secondary  wire  of  a  transformer  having  no  electrical  connection  with 
the  primary  which  alone  receives  the  electric-light  cm-rent.  This 
solution  of  the  ditliculty  is  practicable  with  the  alternating  but  not  with 
the  direct  elect  ric-lin'ht  cm-rent.  "With  the  latter  safety  may  be  secured 
by  sutiicient  rheostat  resistance  in  each  branch  of  the  circuit  before  it 
reaches  the  apparatus  at  all.  No  such  danger  attends  the  application 
of  these  currents  from  apparatus  actuated  by  ordinary  galvanic  or 
storage  bat  lories. 

Relative  Conductivity  at  the  Contact  Between  a  Shoe  and  Various 
Surfaces,  Wet  and  Dry.-  Result  of  experiments  by  the  author  May  12. 
l!U'.'.  1  identified  one  of  the  direct  electric  wires  as  the  charged  one 
and  found  its  voltage  as  compared  with  that  of  the  earth  to  be  110. 
Through  a  -cries  socket  and  a  2">-watt  Mazda  lamp  this  wire  was  con- 
nected with  one  terminal  of  a  milliamperemeter.  sufficient  rheostat  re- 
sistance was  introduced  to  protect  the  meter  from  an  undue  strength  of 
current  and  the  shoe  from  being  burnt.  And  this  rheostat  resistance 
was  not  varied  during  the  course  of  the  experiments.  A  win1  led  from 
the  other  terminal  of  the  milliamperemeter  to  an  electrode  consisting 
of  a  carbon  plate,  about  the  length  and  width  of  the  foot,  which  with  a 
moistened  pad  was  stuffed  into  a  shoe.  The  latter  was  not  new,  but  had 
been  half-soled.  The  shoe  rested  of  its  own  weight  upon  the  surfaces 
described  and  the  milliamperementer  showed  that  the  strengths  of 
current  described  passed  through  the  shoe  to  the  earth. 


Dry. 
Dry. 

I  )ry 
Dry. 
\\V-t. 

\\.  •' 
\\.  • 


\\  •  • 


Dry  wood  floor  one  story  above  the 

ground. 
Dry   tiled   floor  one  story  above  the 

irrouiid. 

Dry  cement  floor  upon  the  ground. 
U  et  cement  floor  upon  the  Around. 
The  Mime  dry  cement  floor. 

The  Millie   uet    cement    floor. 

i  )ry    i  iled    floor   one   story    above   the 

Around. 
1  )ry   v, '  ""I    floor  one  story   above   the 

ground, 
\\Vt    |j|,.,|    f!,,,,r  ,,,,,.   vtory   above   the 

<i rou in  I. 

line   wet    tiled   floor  \\itli   pool  of 

water     extendim,.'     to    -team-pipe    f, 

inches  from  -hi  ie, 
U  -i    wood   floor  one  story  abovi    the 


None. 

]()  milliainporcp. 

1  milliainpere. 

20  milliainperes, 

None. 

None. 

None. 
1  milliampero. 

Xone. 
'•'>  milliamperos. 


Grounding  one  pole  of  a  battery,  static  machine,  or  any  other  gen- 
erator   n  ,    carrvinu   a    eouduct  ing   wire   to   anv   metallic 


KLKCTKO PATHOLOGY  :ili5 

object  which  is  connected  with  the  earth.  The  eartli  is  so  large  and 
such  a  good  conductor  of  electricity  that  it  will  immediately  receive 
and  distribute  in  many  directions  any  ordinary  quantity  and  quality 
of  electricity.  The  part  of  the  conductor  in  immediate  contact  with  the 
earth  becomes  of  zero  potential  and  may  be  handled  by  a  person  in 
contact  with  the  earth,  but  not  by  a  person  in  contact  with  the  other 
pole  of  the  generator.  The  difference  in  voltage  between  the  poles  of  the 
generator  remains  the  same  as  before,  though  the  absolute1  voltage  of 
one  is  zero  and  of  the  other  twice  the  value  that  it  had  when  one  pole 
was  -f  and  the  other  — . 

Grounding  One  Pole  of  a.  Step-down  Transformer.—  With  certain 
electrical  services  this  should  always  be  done  before1  the  alternating 
current  electric  light  wires  are  brought  into  a  building.  Then  if  any 
defect  occurs  it  is  impossible  for  the  550  volts  transmission  current  to 
charge  that  wire  at  all  or  the  other  one  with  more  than  225  volts.  A 
shock  from  the  latter  is  not  dangerous  ordinarilly.  while  one  from  the 
former  may  well  be  fatal.  But  with  certain  other  services  grounding 
the  secondary  may  be  dangerous. 

"Where  a  normal  voltage  in  excess  of  250  is  possible  between  any 
wire  of  a  secondary  circuit  and  ground,  it  is  doubtful  whether  the  sec- 
ondary should  be  grounded,  because  shocks  to  ground  from  such  a 
system  might  cause  death."1 

Grounding  one  pole  of  the  battery  or  other  generator  for  teleg- 
raphy and  also  one  pole  of  the  telegraph  instrument,  so  employing  the 
earth  as  a  return,  is  well  known.  It  is  an  element  of  safety  in  case  of 
lightning  or  crossing  by  the  high  tension  wire. 

Grounding  one  pole  of  the  static  machine  and  the  high  tension 
circuit  for  ignition  in  an  automobile  (page  C>()'i,  and  in  wireless  teleg- 
raphy (page1  5(>7\  and  of  an  .r-ray  generator  (page1  782).  and  ground- 
ing lightning  rods  (page  226')  are  important  applications  of  these 
principles. 

Pathology  of  Very  High-tension  Industrial  Currents. — The  electric 
transmission  of  power  for  long  distances  is  most  economically  effected  by 
the  use  of  an  alternating  current  of  very  high  voltage.  The  power  for 
all  the  street-car  systems  of  the  city  of  Buffalo  is  sent  from  Niagara 
Falls,  about  fifty  miles  away,  in  the  form  of  an  alternating  current  of 
00,000  volts.  The  weight,  and  consequently  the  expense,  of  the  copper 
conductors  required  for  the  transmission  of  the  required  number  of 
horse-power  in  the  form  of  a  current  of  (>00  volts  would  be  100  times  as 
great.  The  higher  tension  current  is,  therefore,  used  for  the  long-dis- 
tance transmission,  and  is  reduced  to  the  utilization  tension  of  550  volt> 
by  suitable  transformers  in  the  city  where  the  power  is  to  be  used. 

The  tension  of  (>0,000  volts  is  so  great  that  it  will  spark  across 
an  air  space  of  a  do/en  inches,  and  the  ;imperage  carried  by  these1  con- 
ductors is  very  great.  It  means  death  undeT  most  circumstances  to 
receive1  a  discharge  from  one1  of  the'se1  conductors,  and  so  they  should  be 
guarded  in  such  a  way  that  no  one  can  come  near  them.  The  lesions 
produced  are  very  much  the  same  as  those1  produced  by  lightning:  burn- 
at  the>  point  of  e'ntranev  and  of  e>xit,  and  areas  of  elisintegration  and  ex- 
travasation in  the1  organs  traversed  by  the  ctinvnt.  [If  both  wire's  we'iv 
touche'el,  death  would  be'  practically  certain  unless  the'  two  points  ot 

1  American  Electricians'  Handbook.  Terrell  Croft.  Mc(lra\v  it  Hill  Co..  New 
Y  r\  an<l  London.  I'.Ho.  p.  )->9M. 


otiti  Ml.DICAI.    Kl.KCTKK  l.TY    AND    KoNTCKN     KAYS 

contact  wciv  clo-e  together  and  upon  the  same  limb.  Kven  then  a  terri- 
ble burn  would  In-  produced,  with  ]>rolial)lv  ]>enn:uicnt  impairment  of 
Usefulness  in  the  limit.  If  the  man  were  holding  the  wire  when  the  eur- 
:  •  •:/  \\  us  :  urned  on.  muscular  contraction  would  cause  the  hand  to  grasp 
'he  wire  with  a  <rrip  wliirli  could  not  he  released  voluntarily.  It  would 
i>e  pract  ii-alh'  sure  death  for  aiiv  one  else  to  try  to  release  him  except 
bv  promptly  turning  oft'  the  current. 

1:   Hilly  one  win-  is  touched,  the  current   emerges  from  the  body  at 
i  he    place    where    a    connection    is    made    with    the    ground.      And    the 


iirreni  traversing  the  body  will  depend  upon  the  nature    ' 


>l  tiiis  Around  connection.  A  man  wearing  dry  rubber  overshoes  and 
standing  upon  n  dry  wooden  flour  would  receive  less  current  than  if 
he  were  standing  upon  a  metal  floor  and  had  nails  in  his  shoes.  Then, 
arrain,  rubber  Cloves  would  diminish  the  strength  of  the  current.  But 
with  an  alternating  current  of  (ill. 000  volts  these  would  usually  all 
fail  to  prevent  a  fatal  accident.  There  is  probably  no  way  in  which 
live  wire.-  a'  this  voltage  can  be  safely  handled.  Death  occurs  from 
irreparable  lesions  in  the  central  nervous  system  paralyzing  both 
re-piration  and  circulation.  Treatment  in  accidents  witli  such  a  volt- 
age i-  u'-ii'-rallv  unavailing. 

High-tension  Currents  of  1000  to  10,000  Volts.— These  are 
alt. -mat  inur  currents  employed  in  power  transmission,  and  accidental 
'  it  •  •  with  the  conductors  i.-  usually  fatal.  Here,  however,  the 
'<  :.-: -M  i-  so  much  less  than  in  the  case  of  lightning  and  of  the  currents 
of  tin. iii  111  volts  that  many  of  the  circumstances  already  alluded  to  may 
previ  •  •  fatal  amount  of  current  from  traversing  the  body.  The 
mj  inc.-  produced  by  the  full  strength  of  the  current  passing  through 
'he  bod}  from  head  to  feet  are  similar  to  those  from  lightning  or  the 
Hi  1. 1  M  M  i  volt.-  current:  burn-  at  the  places  of  contact  and  areas  of 

!i-itite'_rrat  ion    mid    extravasation,    especially    in    the    central    nervous 
'••    .        !»••:••     results    from    destructive    lesions  in    the    circulatory 

I  :.'    bod}    •;  ay  form  a  complete  short  circuit  between  the  two  wires 

intact  with  only  one  wire  ami  the  ground.     The  current 

is       i         lull  t  In    bod}    from  "in-  hand   to  the  other  miirht  be  fatal, 

be  rec  i\  ered  from.      It   has  a  tendency  to  produce  muscular 

irrippinu   of  the   wires  and    respiratory 

•i-.      (  M  her   portion-   may   be   traversed   bv   a   current 

"  •  •  Us  are  taken  in  resuscitate  the  patient  from 

'o  the  nervous  system,  recovery  may  take  place  with 

'.•  : . '  t   of  cert  a  in   muscles  <  >\  organs. 

-ame  as  recommended  in  case-  of  lightning-stroke. 
ce  t  hat   these  cases  should  be  1  reated  as  if 
iiitiedli}   the. -hock:     riot   Lriven  up  as  dead  without 
1  a'  ioii.      I  .;•  •  •  t    or   the    respirat  ii  in    may 

all    e\te)   '     ;    -    never    -poll  t  alieoiisl  V    to    renew    their 

'  •  '  '     'il    In    iii  :    condition  to  be  -aved  by  art  ificial 

.     tii     .     ni-. 

re- pi  rat i  >ry    paralv-is 

I  ejnelil     :  '.::  '     ill    -nine  o|     1  he.-e    cases    one    is    t  niC 

I  A  en    -i]c]|  element  -  as 

•  •  ••  ' .   '  •      tin    \  id  in,  and  the  coiidit  ion  of  the 
•     a   del.  effect    ni  path  of 


KLKCTKOI'ATHOLOGY  307 

the  current  through  the  body  and  the1  quantity  which  readies  particular 
organs. 

Electrocution, — An  alternating  current  of  1700  volts  from  a  dynamo 
applied  by  means  of  metal  bands  passing  around  the  head  and  the 
ankles  sometimes  requires  several  applications  before  life  is  extinct. 
These  are  of  only  a  few  seconds  each  and  the  entire  process  occupies 
(inly  a  very  few  minutes.  It  is  probable  that  complete  insensibility  is 
produced  instantaneously,  but  involuntary  muscular  contractions 
and  the  fact  that  more  than  one  application  is  sometimes  required 
make  it  a  distressing  sight  for  those  whose  duty  it  is  to  witness  it.  The 
different  elements  which  prevent  a  good  contact  with  the  body  or  pro- 
vide a  path  for  the  transmission  of  the  current  along  the  surface  of  the 
body  instead  of  through  it  are  responsible;  for  occasional  unsatisfactory 
results.  Death  is  due  to  respiratory  paralysis  and  it  is  in  cases  in  which 
respiration  begins  again  that  additional  applications  of  the  current 
are  necessary. 

y.  Jellinek  has  written  a  monograph  on  death  by  electricity,1  in 
which  are  found  pictures  of  the  gross  and  minute  lesions  occurring  in  the 
brain,  cord,  and  different  viscera. 

Death  front  High-tension  and  Low-tension  Currents  (see  also  pages 
~)3()  to  537). — High-tension  currents  cause  death  by  respiratory  paral- 
ysis, low-tension  currents  by  cardiac  paralysis,  if  they  cause1  death  at  all. 
This  is  true  in  general,  but,  of  course,  a  current  which  has  a  high  voltage 
at  the  terminals  of  the  dynamo  may  be  so  modified  by  the  circum- 
stances surrounding  the  man  who  accidently  receives  it  that  only  a 
fraction  of  that  voltage  is  applied  to  his  body,  and  the  heart,  not  the 
respiration,  is  paralyzed. 

Prevost  and  Battelli  have  made  many  observations  upon  death 
by  electricity2  and  have  found  that  animals  in  whom  cardiac  paralysis 
has  been  produced  by  low-tension  electricity  may  be  resuscitated  by 
high-tension  electricity.  This  was  done  in  the  case  of  a  dog — one 
electrode  in  the  mouth,  the  other  in  the  rectum.  A  o()-volt  alternating 
current  was  applied  for  three  seconds  and  produced  heart  fluttering,  a 
condition  of  feeble  and  rapid  action  of  the  heart,  which  is  the  way  in 
which  electricity  paralyzes  the  heart  and  from  which  spontaneous 
recovery  seems  to  bo  impossible.  A  few  seconds  later,  however,  the 
application  of  an  alternating  current  of  4M)()  volts  tor  two  seconds 
caused  a  return  to  normal  cardiac  action,  and  the  animal's  life  was  saved. 
It  does  not  seem  a  desirable  experiment  to  try  in  the  case  of  a  human 
being,  because  of  the  probability  of  producing  destructive  lesions  in  the 
central  nervous  system  from  the  passage  of  a  current  of  such  volume  as 
the  4800-volt  alternating  current.  Faradization  of  the  pneumogastric 
nerve  for  brief  periods  is  a  means  of  applying  a  current  of  moderately 
high  tension  and  of  a  quantity  so  small  as  not  to  be  capable  of  producing 
pat  hologic  effects. 

h'tiniion  »f  Rapid  it 'i  of  Alternation  to  the  Physiologic  ami  Pathologic 
EjT<ct  of  High-tension  Current*.  Industrial  currents  usually  have 
about  fifty  alternations  a  second,  and  this  rate  causes  the  greatest 

^"  Klpotropathologip,"  published  l>y  Knkr.  Stmttrart,   HHW. 

"  Coinptcs  rendus  de  1' Academic  d«'s  Sciences,''  vol.  cxxviii,  r\\x;  ".Journal  de 
Physiologic  et  de  Pathologic  irenerale,"  Is'.)'.),  HUH);  "Revue  niedieale  de  h  tfuisse 
Rnmande,"  1X'M>,  1000. 


oti.S  MKDICAL    KI.KCTIUCITY    AND    Il(")\T(iKN     KAY> 

effect  upon  living  organisms.  The  highest  voltages  at  this  rate  of 
alternation  arc  so  dangerous  that  even  an  a|)]>r(>acli  to  the  conductors 
should  he  effectively  guarded  again-t.  •">.">()  volts  is  often  deadly  and 
<*i  to  11")  volt-  occasionallv  so  under  exceptional  circumstances. 

\lii-Miatiii-  discharges  are  dangerous  in  proportion  to  frequency  up 
tn  l.'iil  a  second  and  become  pn>o;ressively  less  effective  physiologically 
bevond  that  frei|Uencv.  A  very  much  more  rapid  rat<-  of  alternation 
render-  the  same  or  even  higher  voltages  hannless:  and  even  deprives 
the  current  of  it-  propertv  of  producing  sensation  or  muscular  con- 
traction.  Tesla,  Thomson,  d'Arsonval,  and  others  have  performed 
experiments  in  which  high-frequency  and  high  potential  currents  are 
passed  through  the  body  in  suiiicient  (juantity  tu  light  a  Hi-candle-power 
incandescent  lamp  requiring  a  current  of  \  ani]>ere  under  ordinary 
conditions.  These  g<>  to  show  that  alternations  above  ")()()()  a  second 
'.  ise  the  ordinary  effects  of  electric  currents  upon  the  living  organism. 
And  experiments  by  1'n'vost  and  Hattelli  with  machines  giving  alterna- 
tion- all  the  way  up  to  1701)  a  second1  show  that  the  more  rapid  the  rate 
of  alternation,  the  higher  is  the  voltage  required  to  produce  death  or 
other  pathologic  results.  Of  course,  ''high-frequency  currents"  are 
of  a  transcendental  order  of  frequency,  consisting  perhaps  of  millions  of 
o-cillat  ion-  a  second,  forming  a  to-and-fro  discharge  between  the  coatings 
of  a  condenser  in  the  course  of  which  their  electric  charges  are  liberated 
and  iientralixed.  This  discharge  and  these  oscillations  do  not  take 
place  directly  through  tin-  patient's  body,  which  forms  only  a  shunt 
circuit  for  the  discharge.  The  principal  path  afforded  for  the  current 
in  one  tvpe  of  high-frequency  apparatus  is  through  the  short  thick  wire 
solenoid.  And  the  fact  that  any  appreciable  current  passes  through 
the  patient  in-icad  of  all  goinii  through  the  other  much  better  con- 
ducting path  i.-  due  to  the  development  of  an  impeding  self-inductance 
in  the  latter. 

iriirh-frequency    currents    in    the    usual    strength    and    with    a  good 
•    with  the  electrode  produce  physiologic  effects  which  are  often 
|»1    therapeutic    utility.     They   do   not    produce   pathologic   changes   in 
the   I  i>Hies.      I  h<-\    cannot    be   regarded   as  dangerous  to   handle,   since 
bad  effect  i-  ti'om  -park.-.     These  cause  quite  a  sharp  sensation, 
ice  the  ordinary  reflex  muscular  contraction  by  which  nature 
In:  b  to  be  withdrawn  trout  anv  source  of  irritation,  fire  and 
iui    waiting  for  the  sensation  of  pain  to  reach  the  brain 
pulse  to  be  transmitted  to  the  muscles  of  the  limb. 
.'•••   whiteness   and  .-welling  of  the  skin    followed   by 
'-ring  or  ulceration  of  practically  the  nature  of  a  burn 
upon  one  spot   for  too  l^n^  ;t  time.     The  shock  which 
on    accidental  .Barking  is  trivial  and  the  effects  upon, 
!•  -cribed   are   purely   local,  and   require  an  application 
econds   al    a    sinirle   point.     They   are   almost    always 
a.-    in   de-t  rovili'j   cutaiieou.-   uTo\vths. 
irrenl-  applied  as  a  shower  of   -parks  produce,  as 
n'1     i    -harp   reflex    mu.-cular  contraction   and    marked 
'    '      ami     i-   true   uhen   the  elect  I'ode  i-  applied   to  a 
1    •        .    face   of   t  he   bod\  .      The   hi-h    fre(juetic\-   of 
-<•  fiL'un-    in    tin-  uriginul  articles  in 

'   •     '  '      :•     I':l1  Imliii^ic."    1  Ml!). 


ELECTRO  I'ATHOLOCY 


the  alternations  is,  therefore,  not  the  only  element  in  causing  an  absence 
of  sensation  or  muscular  contraction  in  a  human  body,  through  which 
they  pass  when  large1  surfaces  of  contact  are  employed. 

Condenser  Discharges  and  Their  Pathologic  Effects.  Holeling 
a  Ley  den  jar  by  the  outer  coating  in  one  hand,  and  then  touching  1  he 
knob  connected  with  the  inner  coating  with  the  other  hand,  one  receives 
a  spark  and  shock  which  is  influenced  bv  the  capacity  of  the  Leyden  jar 
and  the  voltage  to  which  it  is  charged.  A  sharp  muscular  contraction 
of  the  arms  is  produced  by  such  an  experiment,  but  no  pathologic 
changes. 

Experiments  with  larger  condenser's  have  shown  that  small  animals 
mav  be  killed  by  a  single  or  by  a  small  number  of  successive"  single 
condenser  discharges.  Priestley,  in  1  ?(>(>,  killed  dogs  by  the  discharge- 
from  a  condenser  with  6.5  square  meters  surface  charged  from  a  static 
machine,  .cats  with  3.5  square  meters,  and  rats  with  ().(>  square  meter. 
Since  that  time  various  experiments  and  observations  have  been  made 
bv  Fontana,  Troostwyk  and  Kragenhoff,  Tourdes  and  Bertin,  Richard- 
son, Laz/aretti  and  Albertoni,  and  by  Dechambre.  It  is  to  be  gathered 
from  their  observations  that  a  sufficiently  powerful  discharge  will  kill 
small  animals  and  that  different  lesions  occur,  such  as  ecchymosis  of 
the  pleura  or  edema  of  the  lungs. 

DJ Arson val  made  a  report  in  ISSTMn  a  study  of  the  cause  of  death 
from  the  industrial  use  of  electricity  To  the  effect  that  a  static  discharge 
could  cause  death  only  when  applied  directly  to  the  medulla  and  very 
sharply  localized. 

Prevost  and  Battelli-  have  reported  a  most  elaborate  series  of 
experiments  upon  this  subject. 

Figure  272  shows  the  arrangement  of  the  apparatus,  a  35-cm.  Kuhin- 
korff  coil  being  employed  and  a  condenser  of  adjustable  capacity. 


Fiji.  271'.  —  I),   Spintremeter;    (',    condenser;   d,  explosive   distance;  A,  animal;   S  S,  metal 
spheres  2  cm.  in  diameter,  one  of  which  is  movable  U'revost  and  Battelli). 

Kach  plate  of  the  condenser  was  of  glass  2  mm.  thick,  covered  on  each 
side  by  4S  square  decimeters  (800  square  inches)  of  tin-foil,  and  having 
an  uncovered  border  of  glass  11  cm.  (4',  inches)  wide.  There  were  15 
such  plates,  any  number  of  which  could  he  used  as  a  single  large  con- 
denser, the  capacity  being  0.11)  microfarad  for  each  plate. 

The  spintremeter  or  spark-gap  (I))  of  the  Kuhmkorff  coil  is  set 
at  a  greater  distance1  than  the  explosive  distance*  fd\  which  deter- 
mines the  voltage  of  the  discharge  to  be  sent  through  the-  animal. 
1  his  is  to  prevent  the  discharge1  from  taking  place'  across  the1 

1  "Comptes  rendue  dc  l'Ac:i<l;miir  des  science." 

2  "Journal  <le  Physiologic  et  dc  Pathologic,"  vol.  i,  1M)<».  p.   114. 


;^70  MKD1CAL    KLKCTK1C1TY    AND    HONTCKN    HAYS 

tremetor    and    th.rough    the    Huhmkorff    coil    instead    of    through    the 
animal. 

Tin-  explosive-  distance  (d),  between  metal  balls  '2  (Mil.  in  diameter, 
varies  according  to  the  voltage,  as  shown  in  the  following  table: 

DIFFERENCE    OF  POTENTIAL   BE- 

TWF.F.N    TWO    Sl'IlKKIC    CONDIT- 

DIVI  \NCE.  TOKS    OF    A     DlAMETEK    OK    Two 

( 'K  N  T 1  M  ETEKS   (  H(lttelli) . 

Inches.  Voltx. 

0.008  1,530 

0.016  2,430 

0.040  4,800 

0.080  7,400 

0.120  11,400 

0.160  14,400 

0.200  17,100 

0.240  19,800 

0.280  22,500 

0  320  24,900 

0.360  27,300 

0390  29,100 

0.480  33,000   . 

M  \S-ART    AND    .InriiKKT. 

1  0.39  48,000 

0  78  64,000 

4  1.56  78,000 

These  figures  are  of  the  greatest  interest,  and  much  greater  than 
the  spark  length  of  equal  voltages  where  the  two  opposite  charges  are 
not  bound  together  by  a  tremendous  attraction  and  separated  by 
only  the  thickness  of  a  piece  of  glass,  as  in  a  condenser. 

They  indicate  also  that  if  an  ordinary  Leyden  jar  is  charged  to  a 
potential  of  :;:•!. 000  volts  and  one  end  of  the  insulated  discharging  rod 
i-  applied  to  the  outer  coating,  the  discharge  will  occur  when  the  other 
end  of  the  rod  is  brought  within  1.20  cm.  of  the  knob  connected  with 
the  inner  ci >;\\  ing. 

The  tjinint/t'i  of  electricity  contained  in  a  charged  condenser  or  given 
out  when  the  condenser  is  discharged  is  Q  -TV.  the  capacity  multiplied 
Voltaire  (('  is  expressed  in  microfarads,  V  in  volts,  and  Q  in 


t   111 

•n  ici  >uion;t>- 


d-ciar:_r 


ie    imrl:   [>/ rf»rninl  in   charging  a   condenser  or  performed  by  the 
irire  of   a  condenser    is  W       l('\"J  or  a  number  of   joules   equal  to 
all    the  capacity    in    microfarads    multiplied  by  the  square  of  the 
joule     0.102     kilogram     meter,    or    about     O.S14    foot 

•  of   Prevost   and   Battelli  show  that   the  effect  of  a 
in   causing    death   or  other  injuries   to  animals   is 
number  of  joules  or  to  l('Y'J,  not    to  the   quantity 
Vi. 

i n trie  -mall   I.evden  jar  charged  to  a  certain  voltage 
-alne  effect   on  an  animal  as  a  much  larger  Leyden 
•ondenscr  charged  to  the  same  voltage.      The  quan- 
i  .  1  o2  microcoulombs )   in  a  condenser  of  2. .'is  micro- 
ed   to  a   potential  of   11,100  volts  is  greater  than 
i  niicrocoiilombs )  in  a  condenser  of  0.17  microfarad 


ELECTROPATHOLOGY  371 

capacity  charged  to  3300  volts  potential.  The  energy  or  work  (255 
joules)  in  the  smaller  condenser  charged  to  33,000  volts  is,  on  the, 
contrary,  greater  than  the  energy  (154  joules)  in  the  larger  condenser 
charged  to  11,400  volts.  Provost  and  Battolli  subjected  a  young 
rabbit  weighing  1040  grams  to  a  single  discharge  under  the  above 
conditions  of  small  quantity  (15,510  microcoulombs,  but  large  energy— 
225  joules),  and  the  symptoms  produced  wen;  arrest  of  respiration, 
cardiac  fibrillation,  and  death.  Another  young  rabbit  weighing  1020 
grams  was  subjected  to  a  single  discharge  under  the  other  conditions 
of  large  quantity  (27,132  microcoulombs)  and  small  energy  (155  joules), 
in  which  case  breathing  gradually  commenced  again  and  the  animal 
survived. 

Fastening  the  animal  upon  an  insulated  table,  one  metal  electrode 
was  placed  in  the  mouth  and  the  other  in  the  rectum.  The  polarity  was 
found  not  to  make  any  difference. 

The  size  of  the  animal  determines  the  electric  energi/  as  a  single  con- 
denser discharge  required  to  produce  permanent  arrest  of  respiration  and 
death.  The  most  powerful  discharge  from  their  15-plate  condenser 
(800  square  inches  in  each  of  the  two  sets  of  metal  coatings  charged  to  a 
potential  of  33,000  volts)  failed  to  kill  dogs  weighing  6500,  7000,  and 
8500  grams  (14.3,  15.4,  and  18.7  pounds).  The  electric  energy  applied 
in  the  condenser  discharges  were  cither  1029  or  947  joules,  and  the 
dogs  exhibited  no  symptoms  beyond  slight  temporary  changes  in  blood- 
pressure. 

Rabbits  weighing  about  2000  grams  (4.4  pounds)  required  900  or 
1000  joules  to  produce  a  fatal  result.  For  instance,  a  single  discharge 
from  a  condenser  of  1.27  microfarads  capacity,  charged  to  a  potential 
of  29,100  volts,  and  possessing,  therefore,  an  energy  of  549  joules, 
produced  clonic  convulsions,  temporary  impairment  of  respiration;  the 
heart  beat  normally  and  the  animal  recovered.  Another  rabbit  sub- 
jected to  a  single  discharge  from  a  condenser  of  2.38  microfarads  capacity 
charged  to  a  potential  of  29,100  volts,  and  possessing,  therefore,  an 
energy  of  1029  joules,  showed  no  convulsions,  the  heart  beat  feebly, 
respiration  was  abolished,  and  the  animal  died. 

Young  rabbits  weighing  about  1200  grams  required  about  300 
joules,  and  guinea-pigs  weighing  about  250  grams  required  about  130 
joules,  and  those  weighing  450  grams  about  400  joules  to  arrest  per- 
manently the  respiration  and  kill  the  animal. 

Young  animals  in  general  are  more  susceptible  than  adult  animals. 

Beyond  a  certain  voltage  represented  by  an  explosive  distance 
of  about  1.5  cm.  (/;-,-  inch),  more  powerful  results  are  better  obtained 
bv  increasing  the  size  of  the  condenser  and,  therefore,  its  capacity 
rather  than  by  increasing  the  potential  or  voltage  as  represented  by 
the  explosive  distance. 

The  effects  of  condenser  discharges  upon  animals  are  proportional 
to  the  number  of  joules  (the  number  of  microcoulombs  multiplied  by 
the  square  of  the  number  of  volts),  and  inversely  proportional  to  the 
size  of  the  animal.  A  number  of  successive  discharges  will  produce  a 
cumulative  effect,  but  not  so  great  as  the  same  total  of  electric  energy 
in  a  single  more  powerful  discharge. 

The  pathologic  <t!'<rt  of  a  number  of  conch  user  discharges  in  rapid 
xucccxxinn.  An  adult  rabbit  which  would  be  killed  as  if  bv  lightning 


;i 


le  conden-er  di  -charge  of  <>17  joules  (from  a  condenser  of 
1.71  microfarad-  rapacity.  charu.ed  to  a  potential  of  oo.  ()()()  volts),  will 
survive  two  di-charge-  of  ~>\~  joule-  from  a  condenser  of  (U)f)  micro- 
farad rapacity  charged  to  il'i.OOO  volts'  applied  thirty  seconds  apart. 
Ann-  the  first  discharge  there  were  clonic  convulsions:  respiration  and 
cardiac  action  \\eiv  not  arrested.  After  the  second  discharge  there 
\\riv  in  i  convulsion.-.:  respiration  continued:  reflexes  were  absent,  and 
there  was  urea!  inhibition  of  all  nervous  functions.  Recovery  Took 
p!ar.-  gradually. 

Several  ditVereiil  decrees  of  effect  are  recognized  by  Prevost  and 
Matt 

1.     \   simile  ire  ne  nil   muscular  contraction. 

_'.  ('Ionic  convulsions  without  much  effect  on  res])iration,  and  rapid 
recovery. 

;;.   Tonic  convulsions,  momentary  arrest   ot   thoracic  respiration. 

1.  (  ieiieral  inhiliii  ii  in  of  the  nervous  system,  no  convulsions,  loss 
of  reflexe.-:  absolute  arrest  of  thoracic  respiration.  The  auricles  of 
the  heart  arc  often  arrested. 

.">.  Complete  arrest  of  the  heart:  loss  of  excitability  in  the  unst  riped 
:i,u-cle  of  the  intestine;  preservation  of  the  excitability  of  the  striated 

•  11  -cles  and  "f  t  he  m<  >li  •!'  nerves. 

The  hi  .....  [-pressure  varies  according  to  the  severity  of  the  effect. 
In  Prevost  and  Bat  telli's  first  degree  of  effect  the  blood-]  »ressure  becomes 
-liLrhtl;  :  after  a  momentary  fall:  in  the  second,  third,  and  fourth 

ilrirre.-s  it  irenendly  rises  abruj>tly  and  remains  elevated.  In  the  third 
and  fourth  degrees  there  i.-  sometimes  a  fall  of  blood-pressure,  due  to 
fibrillary  tremor  of  the  ventricle.-,  which  is  temporary  in  these  degrees. 
In  rhe  fifth  decree  the  heart  is  unable  to  reestablish  normal  pulsations, 
i  hi  tibi  illary  tremor  continue-  cli  aiming  to  complete  arrest,  and  the  fall 
in  blood-pre.-.-urc  i-  [>ermanent.  There  is  abolition  of  the  excitability 
•  un-triped  muscular  fibers  supplied  by  the  sympathetic  nerves. 

I  he  pathologic  lesinns  are  slight,  such  as  congestion  with  pulmonary 

•  •dei    a   and   -ubpleural  ecchymoses.      Rigor  mortis  is  pronounced  and 

Pathologic  Effect  of  Alternating  Currents.-    Prevost  and  Kattelli,1 
•  ;il    .I.L:  the  different   effect-  of  alternating  currents  on  dogs.  cats. 
rabbit:-,    and    rats,    found    that    the   effect    of   these   currents 
\\a.-    tuiictjonal    dissociation    of    its    movement    and 
-i"ii   of   fibrillary   tremor.       The  same  authors, 
.1  .•!'  death  by  ninii-nnnnti  rnm-ntn,  March  L'7,  1S99, 
ithciently   sti'oii.u  current    was  applied,  n  dog  was 
the    he-art,   fbnllarv  tremor,  while   a   guinea-pig 
i-  "i   respiration.     The  rabbit   presents  momen- 
'      t  re  m  or  of  t  he  heart  .  and  t  hen  a  temporarv 
ree-tabli-hes  itself  ^raduallv.     The  maxi- 
'  In  -e  experiments  wa.-  .").")()  volts.      Alternat  iim' 
•     '<p  to   l'_'n  volt-,  produced  in  the  animal.-  ex]>eri- 
ainl    Hattelli   (dogs,   rabbits,   Lrninea-])igs.  and 
n.pt  oiiis.      The    respira!  ii  >n    was   onl\-    tem- 
1    •    \\  •      '  '  .'    ol   general  sen.-<  iry  c<  indit  ii  ms. 
:,   •  h  r-1  fodi     placed   on   t  he  head  produces  a 
t  hoi    '    .-     ,      n-h  i.-  often  t'olli  iwei  1  1  iv  chn  inic 
-••i  .   March,  .,.   IMi'.t. 


convulsions.  When  neither  of  the  electrodes  is  placed  on  the  head, 
it  requires  at  least  (>()  volts.  When  the  electrodes  are  applied  to  the 
anterior  limbs,  t  he  ventricles  of  the  heart  present  fibrillary  tremor, 
while  the  auricles  continue  to  beat.  This  is  the  same  result  that  is 
obtained  by  direct  electrization  with  an  induced  current.  This  is 
always  fatal  in  dogs,  as  the  heart  does  not  seem  to  be  able  to  resume  it.- 
normal  function.  The  same  is  true  of  adult  guinea-pigs,  weighing  at 
least  400  grams.  The  rabbit  hardly  ever  dies,  because  the  heart,  most 
frequently  resumes  its  rhythm.  The  rat  never  dies,  because  the  tremors 
cease  as  soon  as  the  electrization  is  stopped.  In  dogs  and  guinea-pigs 
respiratory  movements  continue  for  a  long  time,  in  spite  of  the  paralysis 
of  the  heart.  In  this  case  artificial  respiration  could  not  be  of  an\ 
service.  To  produce  the  fibrillary  tremor  of  the  heart  requires  a 
contact  of  at  least  a  second  with  the  electrodes  placed  upon  the  head 
and  thighs,  or  even  over  the  precordial  region.  Preliminary  section 
of  the  pneumogastric  nerves  has  no  influence  over  the  phenomena  of 
fibrillary  tremor  of  the  ventricles.  "Death  by  high-tension  alternating 
currents  from  1200  to  4SOO  volts,  applied  to  the  head  and  feet,  is  not 
due  to  fibrillary  tremor  of  the  ventricles  of  the  heart,  as  in  the  case  of 
low-tension  currents.  They  provoke  in  all  the  animals  grave  troubles 
of  the  central  nervous  system  and  arrest  of  respiration,  loss  of  sensi- 
bility, profound  prostration,  generalized  tetanus,  loss  of  reflexes." 
Death  is  due  to  respiratory  paralysis,  the  arterial  tension  undergoing 
considerable  elevation,  and  the  ventricles  beating  rapidly  and  energet- 
ically, while  the  auricles  are  arrested  in  diastole.  If  the  respiratory 
paralysis  is  permanent,  the  heart  gradually  fails. 

Currents  of  medium  voltage,  240  to  fiOO  volts,  applied  to  the  head 
and  feet,  produce  in  the  rat,  the  guinea-pig,  and  the  rabbit  nervous 
troubles,  but  less  grave  than  those  produced  with  a  current  of  high 
tension.  The  heart  does  not  present  fibrillary  tremor  except  in  the 
rabbit.  In  the  dog.  however,  fibrillary  tremor  occurs  and  death  ensues 
from  simultaneous  cardiac  and  respiratory  paralysis. 

Death  from  the  Action  of  Continuous  Electric  Currents. — The 
electrodes  are  placed  one  in  the  mouth  and  the  other  in  the  rectum  or 
upon  the  thighs.  The  positive  electrode  is  most  often  placed  in  the 
mouth,  but  the  polarity  does  not  make  any  difference.  The  symptoms 
the  same  whether  the  current  is  produced  by  dynamos  or  by 
eries.  Dogs  die  from  paralysis  of  the  heart  with  a  voltage  of 
i  50  to  70.  at  the  least,  while  respiration  continues  for  several 
longer.  The  ventricles  present  fibrillary  tremors  while  the 
auricles  continue  to  beat.  It  was  consequently  useless  to  practise 
artificial  respiration.  With  the  highest  voltages  employed.  550  volts. 
th"  heart  was  arrested  by  a  single  -hock,  opening  and  closing  of  the 
circuit.  Respiration  was  suspended  for  several  seconds  and  then 
recommenced,  but  feehlv  and  slowlv  tailed.  In  guinea-pigs  fibrillary 
tremor  of  the  heart  was  produced  bv  a  ten-ion  of  100  volts,  but  the 


MKDICAL    KI.KlTKU  Tl'Y    AND    HOXTCKX    HAYS 

higher  the  voltage,  the  more  pronounced  are  the.  effects  upon  the 
nervous  system,  except  in  the  case  of  convulsions,  which  are  produced 
when  the  voltage  is  about  50.  and  do  not  occur  when  the  potential  is 
raised  to  550  volts,  and  the  duration  of  contact  prolonged  for  two  or 
three  second-,  for  example. 

D'Arsonval.  having  stated1  that  the  only  danger  from  continuous 
currents  lay  in  the  shock  occurring  when  the  current  was  made  and 
broken.  Prevost  and  Battelli-  made  experiments  to  determine  the  facts. 
I'sing  a  direct  dynamo  current  of  550  volts,  and  having  a  liquid  rheostat 
of  15.OOO  ohms  resistance  in  series  with  the  animal  experimented  upon, 
the  current  was  turned  on  and  off  a  number  of  times  without  effect  of 
any  kind  upon  the  animal.  The  enormous  resistance  of  the  rheostat 
enable-  one  to  turn  the  current  ou  and  off  without  exciting  muscular 
contraction  c-r  -in.y  other  symptom.  After  turning  the  current  on, 
the  resistance  may  be  gradually  diminished  and  the  current  increased 
to  any  desired  strength  without  a  "make"  shock.  It  has  been  proved 
in  this  way  that  fibrillary  tremor  of  the  ventricles  of  the  heart  may  be 
produced  without  any  "make"  shock.  The  gravity  of  the  functional 
disturbances  of  the  nervous  system  is  also  not  appreciably  modified 
bv  the  absence  of  the  "make"  shock. 

The  Effect  of  the  Presence  or  Absence  of  the  "  Break  "  Shock. — 
Kibrillary  tremor  of  the  ventricles  of  the  heart  may  occur  without  the 
"break"  shock,  and  may  continue  and  be  the  cause  of  death  after  the 
s'rvngth  of  the  current  is  gradually  reduced  to  zero  by  the  rheostat, 
tin-  occurrence  of  the  "break"  shock  being  entirely  prevented.  With 
1"W-;  elision  currents,  however,  which  are  not  strong  enough  to  cause 
ary  tremor  without  the  "make"  and  "break"  shocks,  these 
tivrnors  and  the  resulting  cardiac  paralysis  and  death  may  be  produced 
by  a  break  -hock.  This  would  be  done  by  turning  off  the  current 
abruptly  from  its  full  strength  instead  of  gradually  reducing  it  by  means 
of  a  rheostat.  The  "  break  "  shock  from  a  current  of  80  volts  or  even  50 
'Its  applied  in  this  way  will  kill  a  dog  by  fibrillary  tremor  of  the 

Action   of    the  Shocks  of  Opening   and   Closing   the   Circuit.— 
LT!I  enough  tension,  loo  volt  -  in  the  case  of  guinea-pigs,  neither 
'•mn:_r  nor  closing  shock  is  necessary  in  order'  to  produce  fibrillary 
•  oi    tin    heart,   but     with  comparatively    low  voltages,    70   volts, 
'•a-e  n!   dog.-,  'he  heart    continue-    to  beat   during  the  passage  of 
•    the   fibrillary   uvmor   is   produced   by   the  shock  of 
•lit.      With  current-  of  hi<:h  tension,  450  to  550  volts, 
which    had   been    in   a   state  of  fibrillary 
the   current    are  cau-ed  to  recommence 
"•k  ot    breaking  the  current,   but    if  one 
reducing  the  strength   of  the  current 
remains  permanent.      In  the  dog,  on  the 
•  f  breaking  the  current  does  not   reestablish  the 
i    I'revosl    and    Battelli   regard   it    as   probable 
550-vo|l    current    was    not    sufficient    to   pro- 
icks  ot    making  and    breaking  do   not    appear 
influence  upon   the  occurrence  of  troubles  of 

1  '      !'    •:•    "  Vfn.1    -!«•-.  Scicrifcs.  April    t.   ]ss7. 
-.1        •:.  :      i>-   I'ntholotfif  t-t  .If  ['hv-iolomf,    IVJ'J. 


ELECTROPATHOLOGY  375 

the  nervous  centers,  hut  in  ruse,  of  u  current  of  low  tension,  the  condi- 
tion of  generalized  tetanus  is  provoked  by  the  shock  of  breaking  the 
current. 

Absence  of  Pathologic  Effects  from  Leyden  Jar  and  Other  Con- 
denser Discharges  hi  the  use  of  Electrotherapeutic  Apparatus. — 
The  condensers  used  in  high-frequency  apparatus  in  connection 
either  with  a  static  machine,  or  an  induction  coil,  or  an  alternating 
current  transformer  (D'Arsonval-Gaiffe  apparatus)  are  of  small  size 
compared  with  those  found  necessary  to  produce  pathologic,  results 
in  animals,  and  their  effect  is  still  further  reduced  by  the  greater  size 
of  men.  Only  the  smallest  animals  are  seriously  affected  by  powerful 
condenser  discharges.  The  single  muscular  contraction  with  slight 
increase  in  blood-pressure,  which  are  the  effects  produced  upon  men  by 
the  discharge  of  any  of  the  condensers  used  in  electrotherapy,  can 
hardly  be  regarded  as  pathologic.  There  is  no  danger  of  serious  results 
in  handling  this  part  of  the  apparatus. 

History  of  Death  from  Electricity. — Grange1  was  the  first  to  report 
two  deaths  from  dynamo  currents.  He  also  experimented  upon  animals, 
and  considered  that  minute  hemorrhages  in  the  medulla  caused  respira- 
tory paralysis  and  death. 

D'Arsonval's  article  in  1887  was  largely  theoretic.  He  stated  that 
the  discharge  from  a  static  machine  acted  as  a  local  disruptive  agent 
and  permanently  destroyed  the  tissues  affected  by  it.  This  would  be 
the  case  also  with  lightning-stroke.  Dynamo  currents,  he  thought, 
acted  in  a  reflex  inhibitory  manner  upon  the  nervous  ('(niters,  and  this 
inhibition  might  be  received  from  them.  Death  would  be  attributed 
to  respiratory  paralysis,  and  the  proper  treatment  would  be  artificial 
respiration.  This  will  be  found  to  correspond  very  closely  with  the 
most  recent  knowledge  of  the  subject. 

Brown,  Kennelly.  and  Peterson2  reported  experiments  upon  one 
horse,  two  calves,  and  a  number  of  dogs.  Copper  wire  wrapped  with 
wet  cotton  was  wound  around  one  fore  leg  and  the  opposite  hind  leg 
of  the  animal.  An  alternating  current  of  160  to  800  volts  turned  on 
for  a  second  always  caused  instant  death.  A  continuous  current  of 
the  same  strength  and  for  the  same  length  of  time  was  not  always  fatal. 
The  usual  number  of  alternations  was  34  a  second,  and  if  this  was 
increased  to  100  or  134  periods  a  second,  death  was  caused  by  a  current 
of  lower  voltage. 

Tatum3  reported  experiments  upon  animals  in  which  death  was 
caused  by  respiratory  paralysis.  This  occurred  even  when  a  pre- 
liminary section  of  the  vagus  had  been  performed,  and  also  in  atro- 
pinized  animals. 

Electrocution  was  adopted  in  New  York  State  in  1890.  An  alter- 
nating current  of  1500  volts  and  from  15  to  30  periods  a  second  is  used. 
Several  seconds'  contact  abolishes  all  sensibility,  but  the  heart  continues 
to  beat  and  respiration  will  reestablish  itself  unless  one  or  two  more 
additional  shocks  are  given. 

McDonald4  reports  the  result  of  autopsies  upon  several  persons  who 

1  Annalrs  d'hyjiicnc  ct  do  medicine  Icgale,  1885,  pp.  53  and  303. 
•  N.  V.  Mod. "Jour.,  18X9. 

3  Ibid.,  1X90. 

4  Ibid.,  May  14,  Is92. 


iiTli  MKhK'AI.    KLK<    rHH   I  TV     AND    KOXTGKN     HAYS 

had  been  electrocuted.  ( ':i|tillary  hemorrhages  were  found  in  the  floor 
ti f  the  fourth  ventricle  and  in  the  third  ventricle,  hut  they  were  not 
ci  m-t ant . 

liiraud'-  made  three  experiment-  on  rahhits  with  an  alternating 
current  of  L'.'tiMI  volts.  It  took  twelve  seconds  to  stop  the  heating  of 
tin-  heart . 

Philip  Don lii r'  believed  that   the  current   produced  an  alteration  in 
the    hlood    which    caused    secondary    change-    in    the   nervous   system. 
llattelli  -tales  that  these  change-  in  the  hlood  have  not  heen  confirmed 
i  >\   any  >  >t  her  ol  server.  ; 

Kratter  experimented  upon  numerous  animal-  of  different  species, 
u-iim  an  alternating  current.  He  concluded  that  death  was  due  to 
paralvsis  nf  the  respiralorv  center,  the  heart's  action  failing  gradually. 
Diifi  rent  animals  vary  in  suscept  ihility.  (iuinea-pigs  and  rahhits  are 
|e-- -iiscepi  •  an  dogs.  1  Fe  suhmit  ted  rats  to  a  current  of  100  volts, 
.  i.  .  required  thirty  seconds'  contact  to  kill  them.  All  the  other 
ils  were  -uhjected  to  currents  of  higher  tension.  He  did  not  find 
any  con-tant  lf-i<>n-.  either  irross  or  microscopic,  the  hloi»d  and  the 
cells  ui'  i  he  nervous  system  were  unchanged. 

i  >  iver  :ind  Rolan4  experimented  upon  dogs  and  rahhits  with  currents 
nf  _'i  H  i  volts.  There  was  immediate  arrest  of  the  heart,  while  respiration 
continued  until  it  gradually  failed.  They  thought  that  the  effect  upon 
the  heart  was  n  dired  one.  as  it  occurred  just  the  same  when  the  pneumo- 
-  d;\'ided.  The  electrodes  employed  were  moistened  sponges 
which  were  applied  to  the  front  and  hind  legs,  which  had  previously 
heen  shaved.  They  tried  to  re-animate  the  paralyzed  heart  by  various 
met  hod>.  hut  unsuccessfully. 

(  'orradi/  applied  continuoii.-  currents  of  hiirh  tension  to  dogs.  The 
animal-  died  immediately,  even  from  very  >hort  contacts,  and  both 
heart  and  respiration  -eemed  to  he  instantly  paralyzed. 

All   the  above  oh-ervat  ions  are  quoted  more  or  less  in  extenso  in 
I':    vo-t  and  I'at  telli's  excellent  monograph  upon  Death  by  Electricity.) 

Ha'telii    ha-   made  the  experimental  study  upon  which  most  of  our 

knowledge  lit    the  -uhject    i-  ha-ed.       The  <  It  ctriidi  s  for  application 

'i  t  h--  -km  were  made  ot  copper  or  /inc.  covered  with  moistened  cotton. 
1  d  a  ml  the  electrode  bandaged  in  place.      The  mouth 

eleet]      |e-,  foi    dou-,   coii.-isteil   of   two  copper  plate-  placed   in  the  fold 
e  Lrum-  a  nd  t  he  cheek.       llectal  elect  rodes  were  made  of  brass. 
"•nee  ni   cun'ent    wa>  the  alternat  ing  elect  ric-lighl   circuit,  the 
-In    Volt.-    difference    in    potential    bet  \\een    the 
if  the  other-.      Thi-  current   was  niodilied  \t\  a 
.    Lri\  in-    \  oltaiie>   of  dill  I.    I'JIII).    ISOO. 
-Ml  !.         I'tier-e  figure-  I'epi'e.-etit    t  lie  effect  ive  \'o|t  age,  wllicll 

'  irmula    hi-iii-   i  rue    of   sinusoidal 
•I  "    i-i     .   •     rt'eni    ill    .'  •--   i  iia ii    I '_'( )  \~olt s,  a  s] piral 
'    ;  '•'    "i    H  i  ohm-    -  mi  roducei  1  im  o  t  he  circuit ,  and 
I      •!-'<• 

nl'  N  •  \\    Y"rk,   NI  i\  i  in!  M  r  1 1 1.   1  ss'j. 

•     '      I     i  rt  I'iril    :  '  .    !.'     ;./,-.    I  v.  H, 
i  |.-,.    Is;  ix 

-.  ,      .  !-•••'   :    :,.  N.,  ;:,. 

I'     •  •  .  ,i     I  ,,.,,   .    |s«l'.|. 


KLKCTKOPATHOLOGY  '.$~~ 

any  (wo  turns  arc  connected  with  the  electrodes.  Klectric  measure- 
ments are  made  (luring  the  experiment  l>y  means  of  the  voltmetei. 
the  amperemetor,  or  milliamperemeter,  and  Kohlrausch's  telephonic 
bridge  to  measure  the  resistance  of  the  body.  Sometimes  the  contact 
was  as  short  as  one-twentieth  of  a  second,  and  then  the  amperemeter 
or  milliamperemeter  would  not  register;  but  the  strength  of  the  current 
could  be  calculated  from  the  voltage  and  the  electric  resistance  of  (lie 
animal's  body. 

Destructive  Electrolysis. — An  electrolytic  needle  thrust  into  an  organ 
like  the  kidney,  testis,  or  brain  destroys  the  microscopic  structure  of  the 
organ. 

Pathologic  Effect  of  Electricity  Upon  the  Blood.-  I'nder  the  influence 
of  a  powerful  electric  current  Hollet  has  observed  a  dissolving  out  of 
the  hemoglobin  in  the  red  blood-cells,  the  blood  becoming  transparent 
and  consisting  of  a  clear  red  liquid  in  which  are  suspended  colorless  and 
perfectly  transparent  blood-cells.  This  has  been  questioned  by  Herman 
and  (Yenier,  and  must  still  be  considered  as  unsettled. 

Accidents  from  Electric-lighting  and  Power  Currents.-  Fatal  acci- 
dents have1  occurred  with  alternating  currents  of  as  low  as  100  volts. 

As  to  the  amount  of  these  currents  passing  through  the  body,  abso- 
lute safety  requires  that  it  should  not  exceed  25  ma.;  30  ma.  is  often 
dangerous,  and  100  ma.  is  almost  always  fatal. 

The  resistance  of  the  human  body  to  the  direct  current  is  about 
50, 000  ohms  when  a  bare  wire  is  touched  by  a  finger-tip,  and  GOO  ohms 
when  a  conductor  is  held  in  the  hand.  The  same  figures  are  15,000 
ohms  and  200  ohms  for  the  alternating  current. 

Kubber  gloves  are  a  most  uncertain   protection.' 

A  case  of  accident  from  contact  with  a  live  wire  is  recorded  by 
X.  Jacobson.'-'  The  patient  was  a  boy  twelve  years  old  who  took  hold 
of  a  bare  wire  carrying  a  current  of  (5000  volts  and  !H)  amperes  with  his 
left  hand,  while  it  is  supposed  that  his  left  foot  touched  the  companion 
wire,  so  that  the  current  was  short  circuited  through  his  body.  There  was 
not  exactly  a  burn,  but  t  here  ensued  an  impairment  of  arterial  supply, 
either  from  thrombosis  or  vasomotor  contraction,  and  moist  gangrene 
set  in.  The  arm  and  leg  had  to  be  amputated  fifteen  days  after  the 
injury.  There  were  no  special  symptoms  of  constitutional  or  visceral 
disturbance,  and  the  bov  recovered. 

The  wires  were  carrying  a  current  of  four  times  as  many  volts,  and 
from  fifteen  to  forty-five  tunes  as  inanv  amperes,  as  are  required  tor  the 
electrocution  of  criminals.  There  is  tin'.-  great  difference,  however, 
that  in  t  he  case  of  t  he  criminal  care  is  I  a  ken  to  make  a  large  and  perfect 
contact  between  the  shaved  and  moistened  skin  ot  the  person  and 
uimxidizcd  surfaces  of  the  metallic  conductors,  while  in  this  accidental 
case  i  he  wire  was  exposed  to  the  weather  and  its  surface  presumably 
oxidized  and  a  poor  conductor.  The  area  ot  contact  when  a  wire  is 
grasped  by  a  boy's  hand  i.-  small,  and  when  >imply  touched  by  a  boy's 
foot,  is  still  smaller.  Add  to  this  the  resistance  of  the  boy's  shoe 
and  stocking  and  the  possibilitv  that  his  foot  did  not  come  in  contact 
with  the  wire,  but  was  nierelv  grounded,  and  it  is  easv  to  see  that  the 


;I7S  MKDICAL    KLKCTHK  ITY    AND    HONTCKN    HAYS 

iv-i-tance  was  so  great  that  a  ten-ion  of  (ifiOO  would  send  a  very  much 
weaker  current  through  the  1  toy's  body  than  the  90  amperes  which  it 
-end<  through  the  complete  system  of  conducting  wires  to  which  it  is 
designed  to  supply  current  . 

l'ases  treated  by  the  present  author  include  one  in  which  a  telegraph 
lineman  was  injured  by  grasping  a  telegraph  wire  which  had  become 
chained  with  the  ">(M)-voll  trolley  current.  This  happened  in  midair. 
and  as  he  hum:  there  unconscious  the  wire  burned  deeply  into  the  palm 
of  the  hand.  After  a  few  minutes  lie  fell  to  the  ground  and  fractured 
hi-  femur.  He  made  a  good  recovery.  Another  case  was  that  of  a 
man  injured  while  working  upon  the  charged  wire  in  the  slot  of  the 
buried  trolley  wire.  Then-  had  been  a  blinding  flash  as  his  hand 
i'.uched  'he  wire,  and  the  skin  of  the  hand  and  wrist  was  singed  and 
h  .  Hi  d.  There  was  a  marked  reduction  in  motor  power  in  the  hand, 
and  t  hi.-  took  Imitrer  to  cure  than  the  burn. 

Burns  in  Electrotherapy.  The  burn  which  may  be  inflicted  by 
the  ti'iw  of  M  current  of  •_>()  nia.  for  four  seconds,  as  may  happen  if  too 
strong  a  current  i-  used  in  Fort's  method  of  linear  electrolysis,  is  cer- 
tainly not  <lue  to  the  heating  effect  of  the  current.  Experiments  by 
Laurel  and  iVllocq1  show  that  the  elevation  of  temperature  for  the 
entire  surface  of  contact  between  the  uninsulated  part  of  the  electrode; 
and  the  tle.-h  would  be  only  about  12°  V.  This  rise  of  temperature  is 
ii"'  dioir_:'h  to  redden  the  mucous  membrane  or  to  produce  anv  uncom- 
fortable sen.-at  ion. 

A  -iniilar  state  of  things  is  found  when  one  comes  to  measure  the 

amount   of  an  acid  or  base  set  free  at  the  surface  of  the  skin  by  eloc- 

troly-i-  of  the  liquid  which  is  used  to  moisten  the  electrode;.      In  one 

experiment  l>\   Laurel  and  Belloeq  all  electrode  moistened  with  a  1  :  1000 

i]  it  ion    ui    caustic    potash    produced    a    burning    sensation    upon    the 

operator's    Ion-arm    which    could    hardly    be    borne    with    a    current    of 

.  applied  for  two  or  three  seconds.      A  calculation  show.-  that  only 

milligram  "t  pota.-h  was  set  free,  not  enough  in  an  ordinary  chenuc 

'.•  •!    to   produce   any   perceptible  effect    upon   the  skin.     The  effect 

1  ••  solutions  employed  and  the  exact   arrangement.      Some 

"    '    •    •  "t  her  experiments  upon  t  heir  own  forearms  were  as  follows: 

(  ".'•  •  led  rode  con.-ists  of  a  lit  t  le  glass  cylinder,  open  top  and  bot  torn, 
•  Men  applied  to  the  skill,  can  be  filled  with  a  liquid.  The 
i"  i!  '  "  in  ued  by  t  he  pat  lent  '.-  skin,  and  a  wire  passes  into  the  liquid 

:'  I  he  top.  Another  electrode  consists  of  a  porous 
II  nl  liquid  into  which  a  wire  dips  and  the  bottom  of 


indifferent    positive  pole  at   upper  part   of 
t  n>de   ui    ordinary   size  covered    with    moist 
or    Ml    ma.    was    required    to    produce    the 
ve.      L*  ever.-  in  ^  t  he  cu  rrent  ,  20  ma.  were 


ELECTUOPATHOLOGY  379 

of  sulphuric  acid  was  used  as  the  active  electrode,  and  the  same  burning 
required  only  2  ma. 

Fourth  Experiment. — The  glass  cylinder  full  of  ToY<y  solution  of 
caustic  potash  was  used  as  the  active  electrode,  and  the  same  burning 
occurred  with  a  current  of  3  ma. 

l''ifth  Experiment,— The  same  acidulated  solution  was  placed  in  the 
porous  jar  and  used  as  the  active  electrode.  A  current  of  8  ma.  produced 
the  same  burning  sensation. 

In  all  the  above  cases  a  reversal  of  the  polarity  made  scarcely  any 
difference. 

Burns  from  currents  of  electrotherapeutic  strength  are  usually  due 
to  ionization. 


ELECTRODES 

MATERIALS  FOR  ELECTRODES 
ELI-XTKODKS   FOR   SURFACE  APPLICATION 

Electrodes  for  Application  to  the  Skin.  —  Klect  mdes  for  the  appli- 

cation  of  the  faradic  current  to  the  surface  of  the  skin  may  consist  of 
indi  r-  In  lie  held  in  'he  hand,  or  metal  plates  for  the  teet  to 
iv-i  ipoii.  liecau.-e  ihe  current  -trenirth  in  millianiperes  is  very  small 
;ind  (lie  current  i-  alternai  iii'-i.  l>oth  these  characteristics  tend  to 
:...  .  nt  chaiiire-  iii  the  .-kin  as  the  result  of  comact  with  the  metal.  It 
a  l-i  i  make-  I  in  le  difference  what  metal  is  cm  ployed. 

Metallic  electrode-;  mav  also  lie  used  for  the  application  of  static 
electricity  and  hiirh-freqnency  current-  of  either  hiirh  or  low  potential. 
The  -mall  amperaire  in  the  tir.-t  case  and  the  alternating  character  of 
::;,-  di.-diai'ire  in  the  case  of  hitrh-frequency  currents  prevent  electrolytic 
effi-d.  I'royidini:  tin-  electrode  is  in  irood  contact  and  is  of  sufficient 
-:,/,•.  no  effect  i-  produced  upon  t  he  skin  at  t  he  place  oi  con  t  act . 

1  he  conditions  are  quite  different  when  the  iralvanic  current  is  used, 

and   e-pedallv    \vhen    strong  applications   of   it    are   mad*-.      The  current 

tinuou-    and    unidirectional,    and    has    the   strongest    tendency    to 

•i-  elect  roivt  ic  effects  in  t  he  t  issues,  even  wit  h  plat  inum  elect  rodes. 

•.:    ich   undergo   practically   no  chanjre  ihemselves.      Additional  changes 

are  ppiducerj   when  copper,  iron,  or  oilier  corrodilde  metals  are  used  as 

Tl,,    />-••".•.  ,,<•<    in   I'ftfrrttitil  Hitn-tni  flu    Eticlrndt-  tntd  the  Skin.    The 

i  ic  i  pie-  lor  ?  he  preveni  imi  of  t  hese  dia litres,  known  collectively 

n.~.  an  In    ciirrenl   density  must   not    lie  toojrreat,      perhap.- 

ire  than       1 1  a.  per  square  cm.,  —am  1  that   the  difference  in  pot  en  - 

1  iei   veon   t  hi    -kin  and  t  he  elect  n « le  must    not    he  1  oo  irreat .       I  f  t  he 

I'ence    in    potential    i-    too    li'i'eat,    diaiiires   a  re    produced    in    the  skin 

ii     '    ,o    •  sample-;    Iroin    ordinary    phy-n-al    processes    may 

hi   •  ."'•'  ::rj    there   i-  a   difference   in   [iiitelltial   lie!  ween 

-  of.  -av.    I  l'i  vo|t-.  and  if  these  wire-  are  allowed  to  touch 

-    a    Mindimr    fla.-h.  and    the  metal    is    melted,    vapor- 

'  •  e|-e  i~  al-i .   t  he  d  a  ii'jer  o|   set  I  ill  ^  f  I  re  to  the  I  iu  ill  1  mir. 

•"ii1    '     .•         Hit  il    I  he   current    i-    I  timed    i  iff.    |>erha  ps   ailP  unat- 

i'll     o|     a     |'u-e.        ( 'out  rast     I  his     with     the    effect 

•:;  re    \'.  ires    connected    wit  Ii    t  he    poles   of   a 

'  ':'  ri  fore,  ha  -,  mi'  a  difference  of  only  I  ,",;"',-,-  \"ol is 

\s  h<-n  t  he  cont  act    i.-  I  D-<  iken.  I  »ut   no 

1  '     all;    toiii  >t  her  and  t  he  difference 

i     t  o 

/•'•      I  he  t  v    i  u  ire     ha  \'e  a  d  il'f<  'fence  in  t  n  it  ent  ial 
11    cunt  aci    .      m;;de  v,  n  h   the  liquid,  and   a  differ- 
II      e-  el      when    1  he  elect  Hide-   an     illl  Iliersed. 
'  "   '  '.'•  •  •  ii    '  •  •  lirl    I  lie  liquid 

t    1  hi     p  '     of  t  he  ciirrenl 

1  '    to  t  he  liquid   i-   accompanied   I,-,-   vapori/at  ion 


ELECTRODKS 


.381 


and  incandescence  of  the  liquid,  so  as  to  form  a  luminous  sphere  around 
the  platinum  point,  and  momentarily  break  the  contact  with  the  liquid 
and  interrupt  the  flow  of  the  current. 

The  effect  in  the  Wehnelt  interrupter  is  never  exactly  duplicated 
in  the  application  of  currents  of  the  proper  intensity  for  therapeutic 
use.  The  flesh  is  never  vaporized  and  ignited,  but  when  heavy  thera- 
peutic currents  are  used,  contact  with  a  small  metallic  electrode  will 
produce  electrolytic  effects,  causing  pain  and  perhaps  even  blistering 
or  dest  ruct  ion  of  the  skin. 

Such  effects  are  obviated  to  a  great  extent  by  having  the  current 
enter  the  body  through  the  intermediary  of  some  substance  having 
about  the  same  resistance  as  the  body.  'There  is  then  onlv  a  slight 
difference  in  potential  between  the  skin  and  the  substance  in  contact 
with  it.  A  sponge  wet  with  a  solution  of  sodium  bicarbonate  may  be 
used  to  cover  the  surface  of  a  metal  disk  connected  with  one  pole  of 
the  battery  (Fig.  273).  The  patient's  body  and  the  solutie-n  then 
form  a  continuous  electrolyte,  and  the  changes  due  to  electrolysis  take 
place  practically  entirely  at  the  surface  of  contact  between  the  metal 
and  the  solution  of  sodium  bicarbonate.  It  is  then'  that  there  is  a  great 
increase  in  the  resistance  encountered  by  the  current,  and  it  is  there 
that  the  electromotive  force  of  the  battery  maintains  a  great  difference 


Fiji.  27'5. — Sponge  electrode  and  insulated  handle. 

in  potential.  The  effect  of  electrolysis  at  that  point  is  seen  in  the 
corrosion  of  the  metal  and  in  a  dissociation  which  ehemic  analysis  would 
show  to  have  occurred  in  the  solution. 

All  the  different  electrodes  for  external  use.  covered  with  moistened 
sponge,  felt,  chamois  skin,  cloth,  clay  or  kaolin,  are  based  upon  this 
principle. 

They  all  possess  another  advantage  over  metal  electrodes  for 
external  use  in  the  fact  that  the  moistened  material  makes  a  much 
larger  surface  of  contact  with  all  the  interstices  of  the  skin.  The  current 
is  supposed  to  be  largely  transmitted  through  the  sweat-glands,  most 
of  the  other  parts  of  the  skin  being  highly  resistant  to  the  passage  of  a 
current. 

Cases  occur,  however,  in  which  the  effect  of  the  direct  external 
application  of  a  metallic  electrode1  is  desired.  The  treatment  of  ulcers 
hv  zinc  iom/ation  is  an  example.  The  active  positive  electrode  is  of 
/.inc.  and  is  applied  directly  to  the  ulcerated  surface,  and  the  caustic 
effect  of  t  he  liberal  ed  /me  ions  is  beneficial  in  some  cases. 

Cl/iil  Klcctro<{rx. — Ordinary  modeling  clay  in  a  moist  soft  condition 
may  be  used  to  secure  a  uniform  resistance  at  all  points  ot  contact  with 
the  skin,  and,  what  is  equally  important .  a  contact  without  too  u'reat  a 
difference  in  potent  ial. 

The  clay  is  shaped  into  a  disk  of  the  proper  si/e,  and  about    I  inch 


MKD1CAL     l.l.i:i    rHK   11  V     AM)    KOVK.KN     KAYS 


thick,  and  a  sheet  of  metal  about  <»ne  inch  less  in  diameter  is  placed 
on  the  .-ide  awav  from  the  patient  and  fastened  to  one  of  the  conducting 
cords. 

('lav  electrode.-  mav  lie  used  for  the  indifferent  electrode  when  heavy 
c.iiTeiit-  are  emploved.  as  for  the  de.-i  ruction  ot  cancer.-  hy  electrolysis 
or  cataphoresis.  and  for  both  the  indifferent  and  the  active  electrode 
when  heavv  currents  are  used  in  the  treatment  ot  neuralgia. 

They  are  much  less  desirable  than  kaolin  electrodes  from  the  stand- 
point ot  cleanliness. 

f\'i»lin  /•,'/(  <//•/*<//  >-.  This  material,  from  which  some  kinds  of  porce- 
lain are  made,  should  he  purchased  in  powdered  form,  and  sewed  up 
in  flat  hairs  of  crash  toweling,  so  as  to  make  a  pad  1  inch  thick,  and  of 
different  sixes,  such  as  x  hy  12  inches  and  14  hy  20  inches.  The  latter 
are  for  the  indifferent  electrode;  when  the  heaviest  currents  are  used. 
The  kaolin  pad-  are  kept  in  water,  and  may  IK:  sterilized  hy  boiling  if 
they  are  to  he  used  more  than  once.  The  largest  sized  pad  will  transmit 
a  current  of  .">(>(  I  ma.  without  burning  if  plaeed  under  the  patient's  hack. 
A  piece  of  flexihle  sheet  metal,  of  the  kind  known  as  x-ray  foil,  2 
inches  less  in  each  diameter,  is  laid  smoothly  over  the  side  of  the  pad 
away  from  the  patient.  A  Xo.  20  insulated  copper  wire  from  one 
pole  of  the  hattery  or  other  electric  generator  has  its  end  bared  and 
passed  through  perforations  in  one  corner  of  the  sheet  metal,  which  is 
then  wrapped  around  and  securely  pinched  to  the  wire.  It.  is  wise  to' 
put  a  piece  i,f  rubber-coated  cloth  between  the  bared  wire  and  the 
kaolin  pad. 

/\'i"//fi  junls  of  suitable  sizes  and  sha|>es  are  also  useful  when  a  heavy 
i-urn-nt  is  to  he  passed  through  the  knee-joint. 

Cnrhnii  i  licirnr/i  .s  covered  with  chamois  and  frequently  rinsed  in 
pure  water  to  remove  electrolytic  products  may  he  used  on  the  delicate 
-km  '  .f  children. 

Electrodes  for  Application  to   Mucous   Membranes. — There  are 
al   reasons   why   these  are  usually   made  of  metal.     They  are  not 
required    to    transmit    the   verv   heavv   cur- 
'••••'  -  foi  :  Lre  kaolin  pads  are  useful. 

I  hey  ;ire  used  chiefly  f.,r  current  s  intended 
'op  duee  a  local  effect ,  which  varies  in 
•  '•'•'"•  '•'  '•:;-.,.-  Irorn  a  mere  st  imulat  ion  t .  < 


.''•n  cau-tic  action.     The  moisture  upon  the  surface  of 

'  '     olten    take-    the    place  ot    the   moistened    Sponge  or 

''•ma]   applications   in   preventing  electrolysis  of 

'  '  •'     however,  only   foj    the  weakest   currents.      A 

'    •'<  current  of  :>  ma.,  and  a  small  electrode 

•  •   •      p:dn  and  frothing  from  Caseous  evolution 

•    '•  '•'  o]    ]  oi'  _'  ma.      Klectrolv.-i-  of  the  tissues  of 


ELECTRODES  383 

a  mucous  membrane  without  the  influence  of  ions  from  the  metal  elec- 
trode is  obtained  by  the  use  of  platinum  electrodes.  The  influence  of 
metallic  ions  is  sometimes  desired,  as  in  treatment  of  fissure  of  the  anus, 
where  a  copper  positive  electrode  may  be  used. 

Bipolar  Electrodes. — These  are  sometimes  used,  especially  in  the 
uterus  or  urethra  (Fig.  274).  The  two  conducting  cords  from  the 
battery  pass  to  two  metallic  terminals  in  an  insulated  stern  of  hard 
rubber,  through  winch  wires  lead  to  two  metal  bands  surrounding  the 
stem.  These  have  an  insulated  space  of  \  inch  or  more  between 
them.  The  effect  of  the  current  is  quite  local,  there  being  practically 
no  general  diffusion. 

Another  form  of  bipolar  electrode  (Fig.  275)  is  suitable  for  external 
use.  One  terminal  is  a  point  in  the  middle  of  a  ring  which  forms 
the  other  terminal.  They  are  \  inch  apart. 

Bipolar  electrodes  are  also  made  for  galvanopuncture. 

ELECTRODES  FOR  GALVANOPUNCTURE 

A  fine  needle  of  platinum  or,  preferably,  iridoplatinum  is  held 
in  an  insulated  handle  as  the  negative  electrode  for  the  electrolytic 
destruction  of  superfluous  hair  (Fig.  276).  A  fine  steel  needle  with 
some  flexibility,  like  a  dental  broach,  may  be  used  for  the  same  purpose, 
and  if  so,  it  is  especially  important  that  it  should  be  connected  with 
the  negative  wire,  because  of  the  iron  staining  of  the  tissues  which  would 
result  if  it  were  the  positive  electrode. 

Needle  electrodes  for  the  destruction  of  vascular  and  other  nevi, 
and  of  tumors,  and  for  the  cure  of  aneurysms,  often  have  an  insulating 
coating  of  collodion  or  varnish  to  prevent  action  upon  the  skin  and 
limit  it  to  the  deeper  tissues  surrounding  the  point  of  the  needle. 

Galvanocautery  Blades. — These  (Fig.  277)  are  not  really  electrodes, 
but  rather  parts  of  a  complete  circuit  where  the  resistance  to  the  flow 


of  the  current  is  so  great  that  the  conducting  material  become?  red  hot 
or  white  hot.  Platinum  is  the  usual  material  for  this  purpose,  and  a 
strip  is  used  which  is  very  thin  and  narrow  when  only  a  few  galvanic 
cells  are  to  he  used,  as  in  most  operations  on  the  nose  and  throat,  but 
broad  and  heavy,  though  only  so  by  comparison,  when  currents  of  50 
amperes  or  more  are  employed  in  such  operations  as  Bottini's,  upon  the 
prostate  gland.  In  some  eases  the  platinum  is  wound  about  a  porcelain 
point,  giving  an  increased  surface. 

Brush  Electrodes. — These  are  made  of  fine  brass  win1,  and  an1  used 
for  the  application  of  faradic  currents  by  nibbing  the  flexible  brush 
lightly  over  the1  surface1  (Tig.  278). 

Roller  Electrodes. — Metallic  cylinders  may  be  rolled  over  the 
surface1  in  certain  applications,  particularly  of  galvanic  and  static 
electricity.  The  roller  may  be  monopolar  or  bipolar  (Figs.  279  and  280). 

Faradization  by  Rolling  Electrode  ("Badigeoner"  of  the  French 
authors). — The  metal  roller  is  covered  with  wet  cloth,  and  as  it  passes 


:',x}  \II:IH<  AI.  KI,K<  TKKITY  AND  ROXTOEX   HAYS 

nver  the  motor  points    causes    muscular  contraction.      It    is  for  thera- 
peutic u-e  rather  than  for  examination. 

Glass  Vacuum  Electrodes.     These  arc  made  the  subject  of  special 
paragraphs  at  p.   I'.'1.'. 


Condenser  Electrodes.     The-e  ;d.-o  are  ,-pecially  considered  (p.  49S). 
Electrode    Handles.     The.-e    h;ive    ;m    in-ulateil    m'i      of    wood    or 


KLKCTKODKS 


iii»;  electrode  handle  (Fig.  281  ),  or  an  insulated  section  may  intervene, 
and  the  electric  connection  between  the  conducting  cord  and  the 
electrode  may  be  made  and  broken  by  a  Morse  key,  which  form.-  part 
of  the  handle'  (Fig.  281?) . 

Intragastric    Electrodes.     These   are  metallic   electrodes  with   an 
insulated  stem  which  may  be   so    flexible   that    the   patient    is    required 


Fin.  27(.K — Monopolar   faradic    roller    dec-        Fig-  'JsO.  —  Bipolar  faradic  roller  electrode 
trode. 

to  swallow  the  electrode  (Kinhorn),  or  so  stiff  that  it  may  be  used  t< 
push  the  electrode  into  the  stomach  (Boas),  or  there  may  be  a  flexibl< 


Fi<^.  2!->l. —  Xon-interrupting  handle  fur  electrodes. 

insulated  stem  and  an  additional  stiffer  one  used    for   introducing  tin 
electrode,  but  removed  later.1 


Fig.  L'SL*. —  Interrupting  handle  for  dootr 


In  everv  case  the  metallic  electrodes  should  be  protected  from  direct 


contact    with    the   tiastric    mucous   membrane   bv    being   enclosed    m    a 


icrforated  shell  of  hard  rubber. 


1  Rasslor,  Jour.  Am.  Med.  Assoc.,  Mav  J.   l'.«)S. 


ELECTRODIAGNOSIS 

THIS  ft  insists  chiefly  in  determinin<:  the  effect  of  electric  stimulation 
nf  nerves  ami  muscles,  and  of  some  special  orirans,  and  in  determining 
the  elect  ric  resistance  c,f  the  body. 

The  Electrodes.  The  active  one  has  a  surface  of  .'•>  square  cen- 
timeter-, and  is  usuallv  applied  at  the  motor  point  of  the  muscle  or 
nerve.  'The  "ther  elect  rude  is  larger  and  is  usually  applied  at  some 
indifferent  part  of  the  body.  They  are  both  thoroughly  \vet  with  a 
.11  of  -odium  chlorid  or  of  -odium  bicarbonate. 

Normal  Electric  Reactions.  The  faradic  excitability  is  more  or 
le--  empirically  determined  l.y  comparison  with  the  similar  adjustment 
•  •  the  apparatus  to  produce  muscular  contraction  in  persons  whose 
|es  and  nerves  are  in  a  normal  condition. 

The  galvanic  excitability  should  lie  such  that  in  most  regions  with 
tin  active  electrode  applied  at  the  motor  point  of  a  muscle  contraction 
takes  place  at  the  cathodal  closure  with  ',  to  1  ma.:  at  the  anodal 
closure,  with  1  to  12  ma.:  at  the  anodal  opening,  with  12  to  12'-  ma.; 
and  at  t  In-  anodal  closure,  with  1  •">  ma.  The  amplitude  of  t  hese  different 
contractions  with  the  same  strength  of  current  is  expressed  by  the 

A  ..  -//Kit    fur  in  /lid  .' 

('a  Cl  ('     An  Cl  ('     An  ()  C    ('a  (>('. 

Tiie    radial    nerve    and    sometimes    the    median    and    peroneal    pve    a 

•..    different   normal  formula,  Cad  ('    An  ()('    AnCiC    CaOC.) 
/'  ''/:7''   -    Lnn's.-   11  i  uk   <~iirr<ntx   mve    only    a   closure   contraction; 
iiloiii    -  .     i  nt*   ii'ive   openimr    and    closure  contractions:    rrr<i   xtrong 
•;  the  direction  of  nerve  conduction  irive  onlv  closure  contrac- 
on-.  and  in  the  twer-e  direction  only  opening  contractions. 

1  h''  entire  <ection  Klect  rophvsiolou'v  is  ot  interest  in  t  his  connection, 
and    especially-     1  )u  I  >oi  — 1  vcymond's    law      paii'e   :>:•'>  \  <    and    the    table   of 
lal  n  act  ions     pain-  !JI1  1  i. 

M"'       I'oin',.      The    illustrations    (Plates    I    si    -how    the    positions 

ictive  electrode    -hoiild   !>,•   placed    in   order  to   produce    t  he 

>-'    i-tt'-ctivf  stimulation   of    the   muscle  or   motor   nerve   in   question. 

<!    partly  upon  the  studies  of    Krl>.  Castex.  and    Schatxki. 

i  p  'ii  persi  inal  i  ihservat  ion-. 

•      \l»\n  •   I',, inf.  .      The    '    ml:   <>f  '/  .   f,n-!ul   in  rrt    may   be 
.  b'.   mean-  '.i  a  -mall  elect  rode  in  t  he  e\t  eriial  audit  ( >ry  meat  us 
il     ml    ijiwa  rd. 

•    •    ,  '     be  stimulated    unh   a    very   small    electrode 
'••rior   b'-rdcr  o!    the   -ternomastoid    muscle.      It    pro- 
'     p  •  it  ii  in.    v.'it  h    p!'>  it  ru-ion    o|      i  he    abdomen    and    a 
•  •       •      t  h  rou  Lrh  l 

'  '.'•    -    '  '  culai     fo->a      ;ind     i1  -    -t  imulat  ion 

.''    '  '    '•:-    ''    ;  '  '    '•'  i'-n    o|    •  he    deltoid.    :  ic>  |i- .    brachialis 

•   r:.ay  In  t  i  he  bend  of  the 

••'•.,  i     ,.,-i    tin    He. \ i, r  tendons. 

Electric    Resistance  of   the   Body.      l;    i-   trcnerally   a   little   lu'^her 


PL. ATI:    I 


H.A  I'H 


/. 


.. 


PI. A  1  I:     4 


PLATH  5 


M.  rvtrahens  aurem 


PLATE    7 


* 


.4g5     M 


. 


_ 


KLKCTROD1AGNUSIS  387 

in  women  than  in  men,  being  about  1400  or  1500  ohms  from  one  hand  to 
the  other  in  women,  and  1200  or  1300  in  men.  This  is  with  hands 
cleansed  by  washing  with  soup  and  water,  and  plunged  in  glasses  con- 
taining salt  solution  at  the  temperature  of  the  body.  Holding  two 
dry  metal  electrodes  in  the  hands,  a  resistance  as  high  as  100,000  ohms 
may  be  found  in  consequence  of  dryness  or  greasiness  of  the  skin,  and  it 
would  vary  with  the  firmness  with  which  the  electrodes  were  held. 

Increasing  the  strength  of  the  current  reduces  the  resistance  of  the 
body.  In  experiments  by  Weiss  the  current  was  at  first  5  ma.  and  the 
resistance  1570  ohms;  increasing  the  current  to  10  ma.  lowered  the 
resistance  to  1350  ohms;  a  still  further  increase  to  23  ma.  lowered  the 
resistance  to  1  HiO  ohms;  then  a  reduction  to  10  ma.  raised  the  resistance 
to  1200  ohms;  and  a  final  reduction  to  0  ma.  raised  the  resistance  to 
1340  ohms. 

These  figures  are  partly  attributable  to  the  effect  of  the  passage  of 
a  direct  current  in  reducing  the  resistance  of  the  body,  for  the  resist- 
ances toward  the  end  of  the  experiment  were  less  than  at  first  with 
the  same  strength  of  current. 

Leduc1  does  not  find  that  moistening  the  skin  or  dilating  or  con- 
tracting its  blood-vessels  by  means  of  heat  or  cold  has  much  effect 
upon  the  resistance,  but  the  profound  anemia  produced  by  adre- 
nalin decidedly  reduces  the  resistance  of  the  skin. 

The  nature  of  ions  and  their  degree  of  saturation  as  produced  by  the 
amperage  and  the  voltage  of  the  current  do,  as  a  rule,  produce  variations 
in  the  resistance. 

Relation  Between  the  Area  of  the  Electrode*  mid  the  Electric  Hcxixtance 
of  the  Bod  if. — The  area  of  the  surface  of  contact  has  quite  a  decided  effect 
upon  the  electric  resistance.  With  the  electrode  moistened  with  a 
solution  of  sodium  chlorid  and  the  skin  already  saturated  with  these  ions, 
a  uniform  electromotive  force  of  6  volts  produces  the  following  num- 
ber of  milliamperes  of  current  with  different  areas  of  contact.  With 
a  surface  of  2  square  centimeters  the  quantity  was  2Tf)f,  ma. 


Surface. 
40  centimeters      

Milliani] 

>eres. 

.'it  i 

4 

.SO 

4 

.60 

,,s 

4 

43 

24 

4 

•>5 

4 

07 

in 

;^ 

7'' 

x          ••             

;> 

55 

7 

:•; 

.30 

2/>X 
2.0.') 


These  figures  correspond  to  a  resistance  varying  from  1200  ohms 
to  2400  ohms,  depending  upon  the  sixe  of  the  surface  of  contact. 

Laws  of  Stimulation  of  Nerves. —  DuBais-Re^mo-nd's  /</"•  is  that 
the  stimulation  is  proportional  t<>  the  variations  which  occur  in  the 
strength  of  the  current  in  a  certain  tune.  Q  bt. 

1  Arch.  d'Klectririte  inr.l..  .lune  '_'.">.   I«t05. 


11,1,,  r,,;  ,u, 'i  M  "</.-•*  have  devi.-ed  formulas  ( /-'  -  <i  i  <  Al,  Ilnorwcg; 
(}  a  ()t.  11  •  s-.v  \\iiicli  are  l>a-ed  upon  the  theory  that  the  -trench  of 
the  current  is  i  he  important  factor,  hut  that  there  is  a  certain  variation 

•    •        ~-  iinulai  ion  produced  by  \  he  make  and  break  of  a  i:a  lvalue  current 
accord  inn   to  the   rapiditv   with   \\i.ieh   the  actual   make  and   break  are 

ipll-hed. 

With  M  current  of  very  slmrt  duration,  such  as  an  isolated  induction 

di-chartri-  or   t  he  discharue  of   a   comleliser  of  small    capacity.  the  time 

.  •  ,~:it   may  lie  disregarded   in  \Yeis.-'s  formula.      (>  is  the  (|Uantity  of 

•    iciiy   necessary   to   produce  stimulation.      'I'he  value  of  li  is  prac- 

•  iperaire  of  the   weake.-t    galvanic   current    which   will 

lee   muscular  conn-actions  when   instantaneously   made  or  closed. 

1      •  ,  bv  means  of  a  condenser  of  known  capacity,  ('.  charged  to  different 

.      •    _.•-   and    '  ii-ciiar^ed.    we   determine   the   voltage,    \.    necessary    to 

proilm-e  contraction.     The  \-olta<:'e  ivijuired  with  the  galvanic  curi'ent 

<  liv  id.   ;  '•,'•    the  aiu]tera.«re  ^ives  the  resistance  H  iii  the  circuit. 

H ""  '  '''«/'•••  form  iln   f'<>i'  xttnitilutitin  />'j  cmidcuxcr  dixchurycs'. 


I:.    •    is  expression    \"   is  the   volta.ire  to   which   the  condenser  of  a 

'  .   i  '  must  he  charged,  and  '/  and  ,'  are  coefficients. 
Clu/ei   find-  that  ()/_'  inicrocoulonib  discharged  in  a  very  short  time 
•    .         ••'  :    ii\    what    mean-)   pi-oduce>  contraction  m  a  normal  muscle. 

<rreater  (jUaiiT]'t\-  is  re<juire<l.  it   indicate-  hyi>o-excitahility. 
To  oltserve  -iir^le  contractions  from  isolated  induct  ion  shocks  turn 
h   <•     '  .••  -ci-ew  of  the  farad ir  interrupter  until  it  will  no  longer  vihrate. 

e  -  sinule  contact  h\-    pressing  it  \\ith  the  tiimei'-tip. 

M  i-ielo    hi'come    wa-ted    when   paraly/ed   hy   organic   disease   of   the 

[o-.vr  inotiir  -eminent   'aiitei'ior  cornua  of  the  cord,  motor  nuclei  at    the 

!ia~e    it;    the    hrain.    neuritis    «i    nerve    injui'y).      l-'aradic    excitability 

iced  iir  i-  just   liecause  tins  torm  of  electricity  can  produce 

:.';-•••]     •     •oniractinu    practically    only    throu.tih    stimulation    of   ner\'e- 

Application   of   Condenser   Discharges   for   Electrodiagnosis. 

:ii'Lre  is  of  such   -hurt   duration    that    the   resistance   of 

not  have  time  materiallv  to  change.      It  i>  unidirectional. 

cMcally    tree    trom    eject  i'ri]\-sis.      These    facts    make   it 

'  .'•:!!-  o!  diagnosis  than  t  lie  Lra!  vanic  curi'ent    U  in  lei'  cert  a  ill 

f  'oiiden-er-  of  capacities  of  frmu  (1.01   to  '2  microfarad-,  or  a  divi>ihle 

'     are   required,   and   a!-o  a   galvanic   battery   of  '.'>(\  to  o(  I  cells. 

'    -in   elect  ric-lij_rj]i    current    may    lie    used.      In    the 

'•'     cniiden-er    ha-   one   armature   grounded   and 

'  '•'•'!    wilji    a    -witch    or    Mnr>e    key,     1\       \-"\u.    ^.Siv,    1  ,y 

-    connected    eitJier    \\llii    one    p.ilr    ,,f    the    batter\- 

HI    ej,     tn.di     applied    to    the    patient.      The   «,tlier    p(,l,.   ,,f    the 

I  lie    other    ejf-el  rode    applied    to    t  lie    patient     is 

A    cell    -elector   enable-    one    to    connect    any    de-ired 

i  >r.    if    -nine   other    xnirce   of   electricity    i< 

-    required.      And   a    voltineler  connect  inu'  the 

"'    '     "'  '  •    niea-ure-  tJie  potential  to  wliicji  1  he  condenser 


KLK(  TKODI.Ui.NOSjIS 


389 


is  ch;ir<z;e(l  when  the  key  connects  the  condenser  with  the  buttery.  Turn- 
in";  the  kev  in  the  opposite  direction  discharges  the  condenser  through 
the  patient.  This  condenser  is  charged  to  gradually  increasing  poten- 
tials until  a  muscular  contraction  is  produced.  Then  the  same  test  is 
applied  with  a  condenser  of  a  different  capacity.  There  should  he  a 
certain  relation  between  the  first  and  second  capacities,  C,and  ( '., 


Earth! 


Second  position  of  key  K. 
Fig.  283.  —  Condenser  discharges  for  electrodiagnosis. 

(microfarads),  and  the  first  and  second  voltages,  \\  and  V2,  in  health. 
Hoorweg  designates  this  normal  relation  by  the  equation 

1          1 


V,  -  V, 


(called  the  condenser  excitability)  in  normal  conditions 
>,    depending   upon   the    motor   point    to  which  the  con- 


The value  of 

is   from   2   to 

denser  discharge  is  applied.     It  is  reduced  to  O.'Jo  or  even  0.07  in  trau- 

matic paralysis,  and  to  0.0006  in  complete  degeneration  of  the  nerve. 

The  intensity  of  the  galvanic  current  required  to  produce  a  minimal 
cathodal  closure  contraction  is  measured  in  milliamperes.  Then- 
is  a  certain  normal  relation  between  this  intensity  /  and  the  condenser 
excitability,  which  is  expressed  by  the  formula 


charged  by  connecting  the  two  poles  of  the  battery  with  the  two  arma- 
tures of  t  he  condenser.     Turning  the  switch  the  other  way  disconnects 

the  battery  from  the  condense!1  and  connects  the  two  armatures  of  the 
latter  with  the  patient.      \<>  t:r<>und  connections  are  required  wnh  this 


li'.K)  MKDICAL    KLKCTKIC1TV    AM)    KONTCiKN     HAYS 

arrangement.  The  double-pole  switch  may  bo  a  hand  OIK'  for  single  dis- 
charges, or  it  may  be  of  the  pendulum  type,  making  contact  with  a  cup 
of  mercury  and  giving  discharges  at  intervals  whose  frequency  is  ad- 
justable. In  the  latter  case  a  separate  battery  of  about  three  cells  is 
usually  required  to  operate  the  switch.  Damp  sponge  or  chamois- 
covered  electrodes  are  used,  the  active  out'  being  !•>  cm.  (about  1  inch) 
square,  and  the  indifferent  one  measuring  ~>  X  10  cm.  (about  2X4 
inches!. 

The  voltage  normally  required  to  produce  a  contraction  from  con- 
denser stimulation  of  the  median  nerve  varies  in  adult-  and  la  rue  chil- 
dren, and  under  different  com  lit  ions,  bet  ween  14  and  JO  volts.  In  young 
children  :->0  volts  are  required,  and  in  tetanus  only  7  or  S  volts. 

Repeated  condenser  discharges  markedly  increase  excitability,  so 
that  a  -mailer  voltage  will  produce  contraction.  Faradization,  on 


the  other   hand.   e\hau-t-    the    excitability,   and    -trongcr   currents   are 
required  after  it   ha-  been  u-ed  tor  a  time. 

With   a    eL'irLMtm    potential   of    UK)   volts  and    the   re-i-tanco  of    1000 

ohm-,   -hown   bv   the  bodv  with  ordinary  wet  exploring  electrodes  and 

conden-er-  <tf  different   eapacitie-.  the  following  table  from   Lewi-  Jones 

.-h.  iw-  the  dura  t  ion  of  discharge  and  t  welve  different  degree-  of  muscular 

bilit  v : 


ELECTRODIAGNOSIS  391 

Normal  muscles  require  0.01  to  0.08;  muscles  with  partial  reaction 
of  degeneration,  0.1  to  0.0;  and  muscles  with  complete  reaction  of  degen- 
eration, 1  to  3  or  more  microfarads  at  100  volts  to  produce  contraction. 

With  still  larger  condensers  longer  waves  should  be  produced,  but 
even  2  microfarads  at  100  volts  produce  a  disagreeable  shock.  The 
best  plan  for  securing  a  reaction  in  the  most  degenerate  muscles  is  to 
use  a  charging  voltage  of  200  or  240  volts,  a  capacity  of  2  microfarads, 
and  a  resistance1  of  4000  ohms  in  series  with  the  patient.  It  is  calculated 
that  the  duration  of  the  discharge  is  increased  to  one-fortieth  of  a  second 
in  this  way  (Lewis  Jones).  (See  also  page  311.) 

Muscular  contractions  from  condensers  of  much  larger  capacity 
parallel  to  the  patient  are  a  new  and  valuable  means  of  electrodiagnosis 
and  treatment  (page  311). 

Abnormal  Electric  Reactions.  -1.  Faradic  H  i/po-excitability  with 
Normal  (ialranic  Formula. — This  may  be  found  in  old  hemiplegia, 
hysteric  paralysis,  primary  nivopathies,  reflex  amyotrophy  from  joint 
disease,  slight  paralyses  of  rheumatic  origin,  or  from  compression  or 
infection  when  the  spinal  centers  are  not  involved,  in  slight  neuritis, 
in  locomotor  ataxia,  and  in  sclerosis  en  plaques. 

2.  Faradic.    Hypo-ex-citabilitij    with    (ialranic    H  upo-excitabilit)/  with 
Xormai  Formula. — This  occurs  in  more  advanced  cases  of  the  same 
varieties  as  enumerated  in  the  preceding  paragraph. 

3.  Faradic  and  (i/ilranic   Hijperexcitabiliti/.—This  occurs   in   recent 
hemiplegia,   Little's  disease,  infantile  hemiplegia,  sometimes  in  chorea, 
at  an  early  stage  of  locomotor  ataxia,  in  tetanus  (more  marked  with  the 
nerve1  than  with  the  muscle),  and  in  cholemia  (more1  marked  with  the 
muscle  than  with  the  nerve).     Galvanic  hyperexcitability. 

4.  Reaction  of  Degeneration. — Electric  examination  in  the  case  of  a 
lesion  producing  degeneration  of  a  motor  nerve  shows  different  results 
at  three  different  stages:   (a]    Immediately  after    an  injury  to  a  motor 
nerve  there  is  faradic  and  galvanic  hyperexcitability  of  the  nerve,  with 
faradic  and  galvanic  hypo-excitability  of  the  muscles  supplied  by  it.      In 
the  course  of   ten  days  faradic  and  galvanic  inexcitability  have  gradually 
developed  in  the  nerve,  with  faradic  hypo-excitability  or  inexcitability 
and  galvanic  hyperexcitability  in  the  muscles,      (h)  After  the  degenera- 
tion  has   become   established,    there   is   complete  faradic  and   galvanic 
inexcitability    of    the  nerve:  faradic  inexcitability  of  the  muscle:  and 
galvanic  hyperexcitability  of  the  muscle,  with  inversion  of  the  formula 
so  as  to  produce  the  "reliction  of  degeneration."   "  RD": 


This  stage  gradually  changes  to  one  of  galvanic  hypo-excitability  with 
sluggish  contractions,  but  with  all  the  other  features  the  same,  (r)  If 
recovery  is  to  ensue,  a  gradual  return  to  normal  reactions  takes  place. 
otherwise  there  is  gradually  a  complete  loss  of  excitability  at  the  motor 
point,  but  excitability  at  the  extremity  of  the  muscle  (Hemak  and 
Doumer's  reaction)  remains,  until  finally  the  muscle  dies  and  all  electric 
excitability  disappears. 

">.  llijpo-excitabilitii  and  Sl/ii/i/ixJi  Contractions. —  Degeneration  is  not 
always  complete,  and  does  not  always  produce  even  inversion  of  the 
formula.  Sometimes  hypo-excitability  and  sluggish  contractions  are 


the   only    symptoms   upon    which    the   elect  rodiagnosis   of   motor   nerve 
degenerat  ion  is  ba-ed. 

I nt(  /•/»/•<  tat/on  i if  tl/i  h'<  art/on  til  Uujtin  ration  a*  l)<'*cntn'({  I  title/' 
JIta<li/i<i*  .'f  ami  •'>.  Thi>  never  occurs  in  paralysis  from  a  cerehraljesion 
or  from  a  lesion  of  the  spinal  cord  which  does  not  involve  the  anterior 
cornua.  Il  is  -trictlv  a  svmptoni  of  injurv  to  the  motor  nerve  and  the 
tranirlion-cells  in  i  he  antei'ior  cornua  from  wliich  it  springs.  It  is  found 
m  infantile  paralysis  (anterior  poliomx  eht  is),  acute  poliomyelitis  m 
adult-,  diffuse  myelitis  involvum  the  anterior  cornua.  hematomyelia, 
traumatic  and  toxic  neuritis,  rheumatic  and  mlective  paralysis,  and  m 
the  Aral)  Muchenne  type  of  myelopathy.  Charcot's  disease,  syringo- 
myeha.  and  amyotrophic  lateral  sclerosis.  ;ind  m  accidental  division  or 
surgical  resection  of  a  motor  nerve,  or  paralysis  from  involvement  in 
bony  callus.  The  reaction  of  degenerat  ion  does  not  appear  in  some1 
slow  cases  of  spinal  muscular  atrophy.  There  is  only  a  gradual  loss 
of  i:al  vanic  excit  al>ilil  y. 

E  j'ii  m  /nation  for  tin  h't  action  of  /)<</</!<  ratio//.  [lave  the  patient 
h<>ld  i  he  positive  electrode  at  some  indifferent  point  and  place  the 
negative  electrode  at  the  motor  point  of  the  muscle.  This  active 
electrode  should  have  a  small  surface,  not  more  than  ',  inch  in  diameter, 
and  should  he  applied  with  a  uniform  pressure  of  about  11  pounds. 
Thi-  pres-ure  -liould  not  vary  while  the  current  is  being  made  and 
l»ro  :en.  The  author's  diagnostic  electrode  is  designed  to  oveicome  the 
:  11  '  -  which  are  present  in  elect  rodes  where  1  he  current  is  t  urned  on  and 
off  hv  the  pressure  of  the  same  hand  that  holds  the  electrode,  and  hv 
uncertainty  as  to  the  amount  of  pressure  exerted  even  when  this  is  not 
the  case. 

Starting  from  zero,  the  galvanic  current  is  irraduallv  increased  in 
st  renirt  h,  while  the  current  is  repeatedly  made  and  broken  unt  il  a  closure 
contraction  takes  place.  The  pole-changer  is  then  reversed,  connecting 
the  exploring  electrode  with  the  positive  and  the  indifferent  electrode 
with  the  negative  pole.  The  position  of  neither  electrode  is  changed, 
nor  is  the  pressure  upon  the  electrode  or  the  rheostat  controlling  the 
-trem_rth  ot  th'1  current  changed.  It  a  closure  contraction  no  longer 
occiu's.  ,  ,[•  it'  n  is  much  wea  ker  than  was  the  negative  closure  con  t  faction, 
there  i-  MO  reaction  of  degeneration,  hut  if  the  positive  closure  con- 
•  ft  iin  eipials  or  exceeds  the  contraction  obtained  when  the  exploring 
I'li'i-T  i-iiilc  was  connected  \\'ith  the  negative  pole,  then  reaction  of  de- 

[ireseut. 

1  '•  •  '•,•'  i-riiit  ract  ion  of  the  particular  muscle  under  examination  is 
'  '  i  i  '•:>:.  -  '  !<••'•.  1 .  not  aliv  'j.<  •!HT:I]  motion  of  the  limit. 

Slo  -<[   i-ont  r;ict  ions  are  the  most    important   features  of  de- 

otni'tiines   ihi1  only   chaniic  In  be  discovered. 

(i.    /  '"  /,''''•''  n  of  f  'nni  fn'i  xxi  i  ni.       11  us  i>  somet  lines  lou  nd  after  a  liml) 

n-'ed  ir.   ;iti  I'.sniarch  band.       I  here  is  normal  or  increased 

'   ibility,  wiih    Lral\'amc    h\'pefe\cit  abilit  y,    and    a    cliaiiu'e    in 

I  'a'  M  '  much  st  n  im;ei    t  ha  M  Usual.      '  'a(  '!'  '     An(  'K  ' 
('in        \  •  i  n 

7     /  p  •    //•••''"    i't'  f-'a'iii'ii  .       lh  is  means  t  ha  I    repeated  c(  »nt  ract  ions 

>•!    and    -'rotifer   currents    to    produce    them.       It    is   on]\- 

-u. -h  ,iise,-|s,.s  as   paralysis  of  cerebral   origin,   hemi- 

.•-  .   -<-iat  i'-a.   proLi!essi\e   mii.-cular  at  ropli\  .  anterior 


KLKCTRODIAONOSIS 

8.  rfhc  Myotonic  Reaction.—  This  occurs  only  in  Thoinscn's  disease. 
It  consists  in  faradic  and  galvanic  hyperexcitability  for  both  the  nerve 
and  the  muscle,  and  in  a  marked  change  in  the  form  of  the  contraction. 
The  galvanic  cathodal  and  anodal  closure  contractions  are  nearly  equal, 
and  are  tonic  and  prolonged.     Anodal  or  cathodal  closure  tetanus  may 
occur   with  currents  of   />   to    10   milliampercs.  and   sometimes   anodal 
opening  tetanus.     Completely  tetanizing  faradic  currents  cause  tetanus 
which  lasts  a  variable  length  of  time  after  the  cessation  of  the  currents, 
and   also   undulatory  contractions   in    neighboring  muscles.      The  latter 
sometimes  occur  with  the  galvanic  current  also.     The  special  phenome- 
non of  myotonia  or  fusion  of  successive  muscular  contractions  is  elicited 
when  the  galvanic  currents  are  made  and   broken  at   moderately  short 
intervals  and  are  of   a  strength  which  would  produce  only  isolated  mus- 
cular contractions  in  a  condition  of  health.      Repeated  muscular  con- 
tractions, either  voluntary  or  electrically  excited,  gradually  exhaust  the 
property  of  myotonia. 

9.  The  Antagonistic   Reaction. — This    occurs    in    multiple  neuritis, 
showing  an   increase   in  contraction  under   intermittrnt  cathodal   stim- 
ulation  and   a   diminished    contraction   when   the   anode   is   the  active 
electrode. 

Rich's  Reaction.  -When  this  is  present,  the  cathodal  closure  con- 
traction and  the  cathodal  opening  contraction  tend  to  become  equal  to 
the  anodal  opening  contraction,  whereas,  normally,  the  latter  requires 
about  ten  times  as  strong  a  current  as  the  former.  This  reaction  seems 
to  indicate!  insufficient  blood-supply  to  the  nerve,  but  it  is  not  always 
possible  to  tell  the  exact  cause  of  this  condition. 

Remak  and  Doumer's  Reaction.  — This  is  a  condition  in  which  the 
muscle  contracts  more  readily  to  a  current  applied  near  its  extremity  or 
near  its  tendon  than  to  one  applied  to  its  motor  point. 

This  reaction  appears  very  promptly — within  one,  two,  or  three  days 
after  the  injury  to  the  nerve — and  may  be  found  in  some  cases  which 
do  not  show  Krb's  react  ion  of  degeneration.  In  the  latter  cases  the  wrong- 
diagnosis  would  be  made  if  the  examination  at  an  early  stage  of  the  case 
were  made  by  stimulation  of  the  motor  point  alone,  for  the  muscular 
response  there  may  be  as  good  as  normally. 

In  the  case  of  a  long-standing  complete  injury  to  a  motor  nerve  all 
muscular  contractility  to  stimulation  at  the  motor  point  may  be  lost. 
and  so  Krb's  reaction  of  degeneration  could  not  be  obtained.  \o 
response  taking  place,  it  would  be  impossible  to  say  whether  or  not  there 
was  inversion  of  the  normal  formula.  In  some  cases,  however,  even  a 
year  or  more  after  a  completely  paralyzing  lesion  of  the  nerve.  Remak  and 
Doumer's  reaction  may  he  obtained  (contraction  from  the  application  to 
the  extremity  of  a  muscle  of  a  current  which  will  not  produce  a  contrac- 
tion when  applied  to  t  he  mot  or  point).  Remak  and  Doumer's  react  ion 
is  more  marked  at  the  anodal  closure  contraction  than  at  the  cathodal 
closure  contraction. 

Electrodiagnosis  in  Eye  Diseases.  It  has  been  known  for  a  long 
time  that  the  passage  of  ('lee trie  currents  t  h rough  the  eye  would  occasion 
luminous  sensations,  and  that  the  making  and  breaking  of  the  current 
and  changes  in  its  intensity  were  especially  productive  of  these  sensa- 
tions. Several  observers  -Ritter.  Purkinje.  Burnham,  Miiller.  Benedict. 
Althaus,  and  La  (irow.  amonu'  others  have  studied  this  effect.  '1  he 


394  MEDICAL    ELECTRICITY    AND    RONTdEN     KAYS 

color  and  shape  of  the  luminous  subjective  image  have  varied  so  greatly 
under  similar  conditions  that  it  is  probable  that  they  are  different  in 
different  individuals.  It  is  supposed  that  there  is  no  direct  connection 
between  the  strength  of  the  current  and  the  color  and  intensity  of  this 
luminous  image.  The  luminosity  is  quite  certainly  not  excited  by 
electrification  of  the  brain  itself.  Currents  which  pass  between  elec- 
trodes placed  at  the  two  sides  of  the  head  do  not  produce  any  sensation 
of  liirht.  although  it  has  been  proved  that  such  currents,  even  if  as  weak 
as  1  niilliampere.  do  actually  traverse  the  brain  substance.  Currents 
applied  to  the  temples,  however,  do  sometimes  produce  luminous 
sensation-,  and  it  seems  probable  that  these  currents  traverse  the  eye  or 
the  optic  nerve  in  part.  A  long  series  of  observations  by  different  men 
has  shown  that  the  sensation  of  color  and  light  is  due  chiefly  to  excite- 
ment of  the  retina,  but  partly  also  to  t  he  excitement  of  the  optic  nerve. 
It  will  take  place,  for  instance,  after  the  eyeball  has  been  removed. 
(See  patre  O.'M  for  experimental  evidence  that  stimulation  of  the  optic 
nerve  does  not  produce  sensations  of  light.)  The  strength  of  the  cur- 
rent required  to  produce  this  visual  sensation  is  very  slight  in  the 
healthy  eye.  Placing  the  negative  electrode  upon  the  temple  and 
the  positive  electrode  upon  the  upper  eyelid,  a  current  of  only  -^ 
niilliampere.  or  sometimes  only  11U  niilliampere.  is  sufficient  to  ex- 
cite a  visual  sensation  in  the  eye.  After  removal  of  the  eyeball,  how- 
ever, a  stronger  current  is  required  to  produce  the  effect.  In  one 
case  tested  eisrht  days  after  emicleation  a  current  of  1  niilliampere  was 
required;  in  another  case  one  year  after  emicleation  I/',,  milliamperes  were 
required,  and  in  one  case,  five  year?  after  emicleation.  .'•>  milliamperes, 
and  another,  ten  years  after  enucleatioii,  5  milliamperes.  In  the  latter 
case,  however,  the  perception  of  light  was  noticed  in  the  sound  eye; 
evidently  the  current  had  penetrated  through  to  the  health}-  eye.  Differ- 
ent disea.-es  of  the  eye  cause  variations  in  the  luminous  sensations  pro- 
dui-ed  by  electricity.  <  )p;icities  and  similar  abnormalities  of  the  refract- 
ing media  do  not  result  in  any  abnormal  reaction  to  electricity,  but 
most  chanires  in  the  optic  nerve  and  in  the  retina  do  result  in  very  great 
impairment  ot  tin-  reaction.  It  may,  therefore,  be  used  as  a  delicate1 
••  •  ;ins  ol  ilia  LTH 
eci  nn 

"  a  ire.  and  is  maintest  at  the  making  and  breaking  of  the  cur- 
-  produced  even   when  the  current    i-  too  weak  to  cause  the 
is  ima  ire.      In  test  ing  t  his  secondary  react  ion  the  intensitv 
-  increased  until  one  has  produced  the  primary  luminous 
•>'    reaction.      Alter  tin-   the  current    is   progressively 
•omes  so  weak   that    the  making  of  the  current   still 
n  ot  liirht.  bin   the  breaking  of  the  current  no  longer 
'U-  phenomenon,    'i  his  is  t  he  minimum  current  which 
indary  rear-iion.  and  in  a  '.rival  n.anv  observations  it 
ndary  reaction  in  a  healthy  subject  is  very 
dways    between     ,',,     and     ,:!fl     niilliampere. 
beiic    retinitis  with    papillary  atrophv   the 
a    current     ot     at     least     ,s:i     niilliampere. 


ELKCTRODIAGNOSIS  3") 

subject,  of  course,  to  the  intelligence  and  imagination  of  the  patient, 
but  this  is  also  true  of  the  measurement  of  the  visual  field.  It  is  of 
experimental  rather  than  practical  interest. 

Electrodiagnosis  in  Ear  Diseases.—  This  is  largely  a  matter  of 
the  production  of  sensations  of  noise  produced  by  electric  stimulation 
(page  4(>9),  and  also  of  the  production  of  vertigo  by  galvanization. 

It  may  often  decide1  between  a  neuropathic  and  an  organic  lesion;  also 
the  seat  and  importance  of  the  lesion.  Ear  lesions  often  cause  the 
muscular  sound  due  to  faradization  to  be  more  distinctly  heard  than  in 
normal  ears. 

Voltaic  Vertigo. —  This  is  a  condition  producing  certain  subjective 
and  objective  symptoms,  caused  by  the  application  of  a  constant  or 
galvanic  current  from  electrodes  1  cm.  in  .diameter,  placed  one  in 
front  of  the  tragus  of  the  right  ear  and  the  other  in  a  corresponding 
place  on  the  left  side.  It  has  a  certain  diagnostic  value  in  diseases  of 
the  middle  and  especially  of  the  internal  ear.  The  patient  feels  dizzy 
and  it  seems  as  if  the  outside  world  were  moving  toward  the  cathode, 
sees  sparks  before  the  eyes,  and  hears  a  noise  in  the  ears.  There  is 
nystagmus  or  oscillation  of  the  eyeballs  if  the  current  is  strong  enough. 
An  important  objective  symptom  is  inclination  of  the  head  to  the  side 
upon  which  the  positive  pole  is  placed.  This  symptom  was  first  noted 
by  Babinski.  who  has  also  found  that  a  rotation  of  the  head  toward  the 
same  side  may  be  produced  by  applying  the  electrodes  in  a  special  way. 

The  condition  is  produced  normally  by  a  current  of  2  to  4  ma., 
while  in  some  diseased  conditions  of  the  labyrinth  or  of  some  other 
part  of  the  internal  ear.  or  an  abnormal  condition  of  the  cerebrospinal 
fluid,  it  may  require  a  current  of  10  or  15  ma.  In  some  cases  of  bilateral 
< lisea-se  voltaic  vertigo  cannot  be  produced  at  all.  If  the  head  will 
incline  toward  one  side  and  not  toward  the  other  when  the  polarity 
is  changed,  this  fact  shows  that  the  lesion  is  unilateral. 

The  condition  is  of  diagnostic  value  in  determining  whether  deafness 
after  an  accident  is  due  to  hysteria  or  malingering  or  to  an  actual  deep 
lesion  of  the  ear.  Other  cases  of  deafness  and  of  Meniere's  disease, 
and  of  intracranial  tumors  and  of  hypertension  of  the  cerebrospinal 
fluid,  cause  modifications  of  voltaic  vertigo  which  are  an  important  aid 
in  diagnosis. 

An  organic  lesion  of  one  internal  car  causes  inclination  toward  that 
side,  no  matter  what  the  direction  of  the  current. 

Faradic  Contractions  in  Myasthenia. — Normally,  the  myograph 
shows  that  the  muscle  remains  uniformly  contracted  as  long  as  the 
influence  of  a  faradic  current  is  applied,  or  at  any  rate  for  a  considerable 
length  of  time.  Fatigue  does  not  begin  for  a  long  time.  In  myasthenia 
there  is  a  steady  fall  almost  from  the  beginning.  The  flexor  of  the 
middle  finger  is  a  desirable  muscle  for  this  test,  and  marked  abnormality 
is  found  in  alcoholism,  pellagra,  general  paralysis,  dementia  prarox. 
senile  dementia,  neurasthenia,  and  epilepsy.  Tracings  in  these  condi- 
tions have  been  published  by  1'ariani.1 

Electrodiagnosis  in  Alcoholic  Peripheral  Neuritis. — There  may 

be  motor  troubles,  with  or  without   the  reaction  of  degeneration.     In 

the  first  class  of  cases  faradic  excitability  is  a  little  diminished,  and  so 

is  galvanic  excitability;  but   then1  art1  no  qualitative  changes,  though 

1  Hivist:t  di  Patologia  ncurosa  <•  inciitalc.  November,  190"). 


.y.ni  MKDit  AL   I:I.K(  run  1 1  v   AND   K<>\K,KX   HAYS 

there  i-  hypersensitiveness  of  the  skin  to  both  currents.  Cases  with 
1'eactioii  of  degeneration  are  quite  rare. 

Alcoholic  cases  without  motor  trouble-;  present  practically  normal 
electric  react  ions. 

Detection  of  Malingering  or  Hysteria  in  Paralysis  after  Injury. 
The  fact  that  voluntary  motion  returns  sooner  than  normal  electric 
react  ion-  after  a  nerve  injury  is  extremely  important .  In  a  case  in  which 
paralv-i-  and  the  reaction  of  degeneration  have  followed  an  injury  or  a 
di-ea-e.  1  he  ret  urn  of  faradic  excitability  without  the  return  of  voluntary 
movement  i-  considered  proof  of  malingering  or  hysteria. 

Record  of  Electrodiagnostic  Examination.  This  should  state 
the  faradic  and  galvanic  excitability  and  qualitative  changes  in  the  same 
mu-cle  or  nerve  on  both  -ides  of  the  body;  thus: 

I  '(/.v///x   ExtcnniR  M  Hxrlt . 

Left. 

--    '.)\  cm.        l-'anulic  excitability       1>  =  7,fi    cm. 

, .    ,         •  ,  .,•       i  < 'ace     =   .">  ma. 

( lalvanic  pxcitamln  v      . 

•    i  Ancc    =    s  ma. 

1 1'  .    lii  itivr  clKinirt1,  -l"\\in---.  (Qualitative  ciian.irc.  none. 

If  t  he  faradic  coil  has  an  adjust  able  number  of  t  urns  in  t  he  secondary 
coil  and  rate  of  vibration  in  the  interrupter,  these  should  be  stated. 
1  hey  -hould  normally  be  the  same  tor  both  sides. 

Various  graphic  charts  have  been  devised,  but  the  simple  written 
record  i-  excellent,  especially  if  supplemented  bv  a  note  to  the  effect. 
for  instance,  that  the  "galvanic  and  faradic  excitability  are  both  reduced. 
and  there  i-  a  slowness  of  contraction,  but  no  inversion  of  the  normal 
•< '  mula." 

1:  the  Leduc  apparatus  is  used,  the  number  of  interruptions  per 
minute  and  the  fraction  of  each  period  during  which  the  current  flows 
-hoiiid  he  stated,  and  also  the  smallest  number  of  milliamperes  which 
c;tU-f-  ci  in*  ract  ion. 

1     :i  condenser  i-  Used,  its  capacity  should  be  recorded,  and  also  the 

'<'.'•_•     to       :    ch    it    -MI-!  be  charged,  so    that    isolated   discharges    will 

"  contraction:  also  the  voltage  which  will  produce  tetanus  from 

The    Electric    Resistance    of    the    Urine    and    of    the    Blood.— 

-lance  of  the  urine  at   (i")°  F.  in  a  U-shaped  electrolytic 
>hm-.       I  ne  greater  the  percentage  of  ehlorids.   piios- 
alid    other    -all-,    the    less    i-    the    resistance'.      The 
mnaturally    <ire;il    in    pneumonia,   diabetes,   acute 
ii-ea-e.   and    pernicious    anemia.       This  means  in- 
1    '  he  pa  rt   ot   t  he  -1<  imeruli  of  t  he  kidne\'s. 
tance    ill    I  he    blood    i-    It.'Jl    ohms    \\hen    mea.-ureil 
1'T-  e  cubic  millimeters  of  fre-hly  drawn 
'•'• "  cup— haped  elertrodes  .'i  mm.  in  diameler, 
-i  lixed  at  a  distance  of  7.")  mm. 

'  '      ;"'  blood   i.  in   healt  h   from  s.">  to   l:!l) 

'    'i    '•'  >ii'i      '    •    .  :  nd  i  he  more  abundant 

the  re-i-tance.     The  saline  constituents,  especiallv 

I'.r  :i    :     M.  ili.'ai  .iMiinial.  ,Iulv  L's.   I'.KWi. 


KLKCTKODIACXOSIS  397 

sodium  chlorid,  arc  good  conductors,  and  the  more  abundant  they  arc 
tlic  less  is  the  electric  resistance. 

The  electric  rexixttnicc  of  the  blood-cells  and  of  other  cells  is  measured 
by  a  method  proposed  by  Xernst.  The  resistance  of  a  liquid  is  first 
measured  and  then  blood-cells  are  added  to  the  liquid  in  a  certain  pro- 
portion and  the  resistance  again  measured. 

Rudolf  Hober  finds  that  the  blood-cells  have  a  conduct  Utility  equal 
to  that  of  a  decinormal  solution  of  potassium  chlorid,  while  the  entire 
J)lood  has  a  very  much  greater  resistance.1 

The  electric  resistance  of  the  lymph  is  regularly  less  than  that  of 
the  serum.2 

The  electric  conductivity  of  the  human  saliva  undergoes  daily  oscil- 
lations which  show  that  it  contains  ioni/able  salts  in  greatest  amount  on 
rising,  then  reduced,  not  much  influenced  by  light  repasts,  but  decidedly 
increased  by  the  principal  meal. J 

The  electric  conductivity  of  cows'  milk  is  about  48.7,  10-4,  and  it  has 
been  suggested  by  Rinaldo  Binaghi4  as  a  test  for  adulteration. 

The  Hemorenal  Index. — This  is  the  quotient  obtained  by  dividing 
the  electric  resistance  of  the  blood  by  that  of  the  urine,  and  it  varies 
normally  between  2  and  .'•>,  the  average  being  4l'>  =  '2. OS. 

An  increase  in  the  hemorenal  index  means  a  diminution  in  the  salts 
in  the  blood,  or  an  increase  of  those  in  the  urine,  or  both.  This  is 
sometimes  found  in  chronic  rheumatism. 

, .    .   .  .  ,  .  Resistance  of  blood.    51 

A  diminished  hemorenal  index,  such  as 

Resistance  ot  urine,      1  lo 

0.44.  was  found  in  a  case  of  pernicious  anemia.  It  indicates  inability  of 
the  glomei'uli  to  transmit  salts  from  the  blood  to  the  urine  to  a  sufficient 
extent.  It  explains  the  danger  that  accompanies  .r-ray  exposures 
in  pernicious  anemia,  which  throw  increased  excretory  work  upon  kid- 
uevs  alreadv  deficient. 


PROGNOSIS  BASED  ON  ELECTROD1AGNOSIS 

When  elect rodiagnosis  and  other  means  show  that  the  paralysis  is 
due  to  a  cerebral  or  a  spinal-cord  lesion,  the  prognosis  depends  upon 
the  nature  of  the  lesion  more  than  upon  the  electric  reactions.  It  is 
in  the  case  of  peripheral  nerve  lesions  that  the  most  valuable  prognostic 
knowledge  may  be  obtained  from  elect  rodiagnosis.  A  case  of  facial 
paralysis  from  exposure  or  rheumatism  may  show  a  continuance  of 
normal  electric  reactions,  and  if  so.  recoverv  may  be  expected  in  about 
three  weeks,  or  there  may  be  galvanic  and  faradic  hypo-excitability, 
meaning  that  recovery  will  take  two  or  three  months.  The  presence  of 
the  reaction  of  degeneration  in  such  a  case  indicates  a  probable  duration 
of  six  months,  with  a  possibility  of  permanent  paralysis.  Lesions  of 
other  peripheral  nerves  are  judged  in  a  similar  way. 

Complete  loss  of  nerve  excitability,  with  greatly  increased  galvanic 
muscular  excitability,  with  sluggish  contractions,  indicates  a  severe 

1  Arcliiv.  fur  die  ircsam.  1'hysiol.,  rxxxiii,  2:57,  l!)ll). 

'-'  Luckhardt,  . \nicr.  Jour,  of  Physiol,,  xxv.  :>}.">,  I'.MO. 

Ml.  Polara.  Archiv.  italicnnos  dV  Bi<>l<>«iJ<>.  ljv.  ±->.  HMD. 

4  Hiorhcmisrlics  Pathologic  and  Zur  all^cmrinrn  1'athol..  \.\i.\,  l)l)-7it.  I'.HO. 


ot)S  MKDICAL    KLKrTKIClTY    AND    KOXTCiKN     RAYS 

degenerative  process.  The  possibility  of  sonic  regeneration  remains, 
however,  as  lontr  as  any  elect  ric  excitability  is  present .  but  if  a  year  passes 
without  return  of  faradic  excitability,  and  if  the  muscular  atrophy  has 
been  rapid  and  invat.  otilv  slight  iinproveiiienl  can  e\'er  be  hoped  for. 

\\  ith  an  acute  lesion  and  loss  of  faradic  excitability  inside  of  a  week 
or  ten  da\>  considerable  atrophy  will  follow,  and  the  motor  power  will 
lie  slow  to  ret  urn. 

If  two  or  three  weeks  pass  before  faradic  excitability  disappears, 
the  paraly.-is  \\ill  last  many  months,  but  there  will  be  less  atrophy. 

If  faradic  excitability  remains  normal  or  is  but  slightly  reduced. 
recovery  \\ill  be^in  in  a  lew  weeks  or  months,  and  will  probably  be 
complete. 


IONIC  MEDICATION  BY  ELECTROLYSIS 

A.v  electric  current  may  he  made  to  carry  medicinal  substances  into 
the  tissues  to  a  sufficient  extent  to  produce  certain  physiologic  and 
therapeutic  effects.  The  positive  electrode  is  usually  selected  for 
the  active1  one,  because  it  is  generally  convenient  to  use  a  solution  of 

some  salt  of  a  basic  medicinal  substance.  When  a  salt  is  decomposed 
by  the  current,  the  ions  representing  the  base  travel  into  the  body  on 
their  \vay  to  the  cathode,  and  the  application  is  known  as  cataphorcsis. 
The  effects  of  basic  ionixations  are  manifested  chiefly  in  the  tissues 
close  lo  the  positive  pole,  though  these  ions  may  produce  chemic 
reactions  in  the  liquid  with  which  the  negative  electrode1  is  moistened. 
It  is  easily  demonstrated  that  particles  of  a  substance  ma}"  pass  entirely 
through  the  body,  so  as  to  be  found  on  the  surface  of  the  opposite  elec- 
trode from  the  one  originally  moistened  with  it.  It  is  not  at  all  certain, 
however,  that  particles  of  the  substance  exert  any  influence  upon  the 
deeper  tissties  through  which  they  are  transmitted.  The  effect  seems 
to  be  due  to  the  liberation  of  an  element  or  a  radicle  in  a  nascent  state 
from  the  solution  in  which  the  electrode  is  moistened:  and  it  is  an  im- 
mediate effect  upon  the  first  tissues  subjected  to  it.  The  ions  are 
transmitted  through  the  deeper  tissues  in  a  condition  in  which  they  gen- 
erally do  not  form  combinations  with  the  substances  making  up  these  tis- 
sues, or  wit  h  ions  traveling  in  the  opposite  direct  ion.  The  two  substances 
in  the  latter  case  may  have*  the  stre>iigevst  possible  affinity  for  each  other, 
and  still  show  no  chemic  combination  e-xcept  at  the  two  poles.  The 
same  force  called  electrolysis,  which  is  strong  enough  to  dissociate  ele- 
ments which  can  be  separates!  in  hardly  any  other  way.  is  operative  in 
largely  preventing  anything  but  a  local  el'fevt  as  the  diree-t  result  of 
elect  ric  ionic  medication. 

Merely  dissolving  a  substance-  in  water  converts  a  considerable  part 
of  it  into  ions.  Ionic  medication  is,  therefore,  not  a  specific  enough  term 
in  itself  to  indicate  the-  subject  e>f  this  paragraph. 

Leduc1  has  summarized  our  previous  knowledge1  of  the  stibjevt  of  the 
electric  introduction  of  medicines,  and  has  added  many  valuable1  obser- 
vat  ions  of  his  own. 

It  has  long  been  known  that  electrolysis  takes  place1  at  any  point  of 
contact  between  the  skin  and  an  e'lert  rode  which  is  a  much  bette-r  con- 
ductor; that  the  primary  effect  at  the  anode  is  to  liberate1  chlorin,  from 
tin-  sodium  chlorid  of  which  the1  conducting  portion  of  the1  body  is 
practically  a  solution,  and  oxygen,  from  t  he  water  in  which  it  is  dissolved. 
The  chlorin  is  liberated  at  the  positive  electrode1,  which  it  attacks,  and 
an  oxychlorid  of  the  metal  or  other  base  is  formed.  A  continuation 
of  tin-  effect  dissociates  the  oxychlorid  of  the  metal  and  carries  metallic 
or  oilier  basic  ions  inte>  the1  tissues,  while  the  chlonn  and  oxygen  attack 
fresh  portions  of  the  metal.  A  similar  process  goes  on  at  the  cathexle1 
where  sodium  and  hydmgen  are  liberated,  and  immediately  combine 

1  Ions  ri   Medication  ioniijiif,  Paris,   l'.H)7. 

390 


•UMI 


MKDUAl.    KLKi  TKK  ITY    AND    KONTCKN     HAYS 


with  tin-  acid  element  of  the  electrode  it'  the  latter  is  a  salt.  A  con- 
tinuance of  t  he  process  dissociates  t  his  intermediate  hydrogen  or  sodium 
compound,  and  carries  the  liberated  acid  ions  into  the  body. 

If  one  wi- hed  to  produce  the  effect  of  hydrocyanic  acid,  t  lie  negative 
electrode  \\ould  be  \\et  with  a  -olution  of  potassium  cvanid.  while  to 
produce  I  he  effect  of  strv  rl  ill  ill  t  he  positive  elect  rode  would  be  wet  with 
a  M  'hit  ton  i  >:'  .-I  ryehnin  MI!  j  >hat  e. 

Experiments  in  Cataphoresis.  S.  Salaghi1  has  performed  the 
following  experiment  u  it  h  a  view  to  arrest  ing  and  fixing  in  t  lie  tissues  the 
ion-  which  are  carried  there  b\  a  galvanic  current:  Four  glasses .  A.  B, 
(',  and  1)  i  Fit;.  1'v")  arc  placed  in  series.  The  positive  electrode  of  a 
galvanic  ban  er\  dips  into  A,  which  contains  a  solution  of  nitrate  of  silver. 
Thi-  :Ja--  i-  in  electric  connection  by  means  of  a  strand  of  cotton  mesh 
with  li.  which  contains  a  solution  of  sodium  nitrate.  ('  also  contains 
.-odium  nit  rate  solution  and  is  connected  by  a  CMI  ton  mesh  with  I),  which 
contain-  a  solution  of  >odinm  hyposulphite.  Hand  Care  connected 
by  a  tube  containing  a  dog's  sciatic  nerve  immersed  in  oil.  A  current 
of  1  _'  ma.  passing  steadily  for  twenty-four  hours  will  produce  a  precipi- 
tate of  silver  in  several  centimeters  of  the  length  of  the  nerve  at  the  end 


Tube    containing 
sciatic  nerve  ini- 
Cotton  cord.      mer-ed  in  oil.        Cotton  core 


ixation  ill   ions  in  the  tissues  alter  catapnori'Sis. 


nearest  1  he  anode.     The  precipitate  is  found  exclusively  in  the  myelin 
lie  nerve-t  ubule-. 

Another  experiment  by  I.educ  consists  in  having  two  rabbits  sepa- 

ated    by   absorbent    cotton    wet     with     potassium   cyanid:    the    rabbit 

connected  with  the  anode  is  poisoned.      But  if  the  cotton  were  wet  with 

ochlorate.  the  rabbit   connected  with  the  cathode  would 

iimcation  to  the  author  Dr.  (!.  Betton  Massey  states 

meal   to  which  a  galvanic  current   is  applied  through 

amateil  /me  f/.iiic  dipped  in  acid  and  then  in  metallic 

-hov,    a    Li'i'ay   di>co]or;it  ion,    indicating   a    transportation 

a  I  id  deposit    Hi    •    el  nil  if  mercury. 

Rate   of  Transportation  of   Ions.      It     i.-    important    to  remember 

1 1     i!  pa-.-aLi'e  of  t  he  elect  ric  currejit .  about  t  he  same  as  that  of 

;i  '•"'•''    - :  " •  rent  t  lung  li'om  t  he  -pen  1  at  which  ions  move  through 

!  he  -aim    •  •  '  •••  •  •      •  •  •.      Different  ion.-  mo\'e  at   fixed  rat  es  of  speed,  which 

'•   \l.  M  h    the  eject  t'oniot  i\"e  lorce   \\hlch   ill'l\'e-  it.   and 
•    length  of  eh'ctrolyte  through   \\hich  the  curi-ent 
ha.-  i"     a-- 


IONIC     MKDICATION     MY     KI.KCTKOLYSIS  401 


Silver     ions  move  at  the  rate   of  O.lofi  cm.  per  hour. 
Lithium    "  ••   ().()'.»  J 

Sodium    "  "          "         "      "   o.'.iJC) 

Cerebral  Effects  of  Medicinal  Electrolysis,  (Jautrelet  '  has  tested 
tlie  effect  of  the  >trong  currents  used  in  electrolysis  near  the  head. 
I'sing  the  positive  electrode  with  a  surface  of  100  square  centimeters 
applied  to  a  rabbit's  ear,  while  the  indifferent  electrode  is  applied  to 
the  thigh,  a  current  of  o()  ma.  is  allowed  to  How.  The  effects  produced 
are  of  two  kinds:  an  early  effect,  due  to  the  electric  current  itself,  and 
always  seen,  regardless  of  the  nature  of  the  electrolyte  used  to  moisten 
the  electrode,  and  a  later  effect,  which  is  sometimes  seen  when  such  a 
substance  as  strychnin  is  used  for  the  electrolyte.  The  effects  directly 
due  to  the  current  are  at  first  symptoms  of  peripheral  irritation  of  the 
trigeminal  nerves,  movements  of  the  face  and  of  the  eyes,  and  an  in- 
crease of  the  sensibility  of  that  region.  There  is  a  stimulation  of  the 
cerebellum,  causing  movement  of  the  opposite  paw;  and  bulbar  stimula- 
tion. causing  a  change  of  the  cardiac  and  respiratory  rhythms  and  in- 
creased frequency  of  respiration;  and  a  stimulation  of  the  medulla,  pro- 
ducing cont  ract  ions  of  a.  good  many  different  muscles.  These  phenomena 
of  stimulation  amount  to  epileptic  convulsions  in  the  course  of  fifteen  or 
twenty  minutes,  the  convulsions  being  at  first  tonic  and  subsequently 
clonic.  The  eyes  protrude,  the  pupiis  are  dilated,  the  heart  beats  fast. 
At  a  subsequent  stage  paralytic  symptoms  develop,  the  conical  reflex 
on  the  opposite  side  troin  the  anode  gradually  becomes  abolished; 
spontaneous  movements  cease,  and  movements  ot  the  nostni  and  face 
on  the  same  side  a.  re  abolished;  the  face  is  drawn  toward  the  opposite 
side.  Xo  reflex  occurs  from  a  pin-prick:  sensibility  disapp<  ;•:-  from  the 
face  and  all  parts  of  the  body.  In  these  experiments  an  application  of 
about  one  and  one-half  hours  was  required  to  induce  a  genera';  paralytic 
condition,  which  was  usually  but  not  always  recovered  from,  a  small 
proportion  of  the  animals  dying. 

A  very  different  result  takes  place  when  the  circulation  m  the  ear 
i-  restricted  by  a  clamp  applied  to  the  base  ol  the  ear:  in  a  very  few 
minui  i  s  the  heart  becomes  regular,  re.-  pi  rat  ion  very  rapid,  and  paralytic 
phenomena  are  observed,  especially  Cheyne-Stokes  respiration.  Death 
endues  m  about  an  hour  troin  asphyxia,  the  blood  being  tound  black 
and  containing  unreduced  hemoglobin.  In  this  experiment  few  if  any 
svmpt  on  is  of  stimulation,  and  sea  rceiy  an  v  convulsive  movement  s.  occur. 

If  a  substance,  such  as  strychnin,  is  used,  its  special  effects  become 
apparent  after  a  much  longer  time  than  the  effect-  directly  due  to  the 
current.  If  the  circulation  in  the  ear  is  not  impeded,  the  characteristic 
strychnin  convulsions  take  place  after  fifty  minutes'  application,  and 
the  animal  dies  almost  immediately.  When  the  circulation  i-  cut  off. 
the  st  ry  chni  n  symptoms  do  not  occur  even  alter  the  cessation  ot  the  cur- 
rent or  of  the  direct  results  of  the  current  :  but  it  the  clamp  is  removed 
before  t  he  animal  dies,  t  he  characteristic  symptoms  of  st  rychnin-poison- 
mg  develop  a  few  hours  or  a  day  later.  (M  course,  in  the  latter  case 
the  current  was  .-lopped  entirely  after  the  application  ot  three-quarters 
of  an  hour. 


402  MKOHAI.    KI.KCTKKTry    AND    UOXTCKX    KAYS 

Distinction  Between  Electric  Ionic  Medication  and  Other  Ionic 
Medication.  -Dissolving  any  substance  produces  a  certain  number 
of  ions  of  that  substance,  and  it  is  probable  that  all  medication  depends 
chiefly  upon  these  active  particles  of  the  different  substances. 

Klectric  ionic  medication  is  the  production  of  ions,  and  their  in- 
troduction into  the  bodv  bv  means  of  an  electric  current. 

The  Author's  Technic  for  Electric  Ionic  Medication. — A  four-cell 
hath  is  used  p.  lolli.  Three  of  t  lie  .-hallow  u'lass  t  rays  com  ain  a  solut ion 
oi  sodium  bicarbonate,  and  the  fourth  tray  a  solution  ol  the  medicine  to  be 
introduced.  1  "he  electrode  in  each  tray  is  a  carbon  plate,  and  is  covered 
by  a  piece  of  indurated  fiber  and  felt.  Another  piece  of  felt  is  wrapped 
around  the  part  at  which  the  medicine  is  to  be  introduced,  and  the 
whole  i-  dipped  into  the  tray  containing  the  medicated  solution.  This 
trav  i-  connected  with  the  positive  wire  from  a  table  (p.  4(>1  ).  which 
supplies  galvanic,  faradic.  and  rhythmic  and  ot  her  currents  den  vet  I  from 
the  1  ID-volt  direct  elect  ric-li»'ht  circuit.  The  volt  controller  and  the 
rheostat  are  both  adjusted  so  as  to  irive  no  current.  The  connections 
are  made  for  the  galvanic  current,  and  the  rheostat  and  volt  controller 
art1  siTadually  changed  until  the  millianiperemeter  indicates  that  a  cur- 
rent  of  Ji  i  or  more  milliamperes  is  passing  through  the  body.  .More  or 
less  burning  sensation  is  usually  to  be  expected  at  the  place  where  the 
medicine  i-  introduced,  and  the  amount  of  pain  furnishes  a  Lruide  to 
tin-  amount  of  current  permissible.  The  four-cell  bath  referred  to 
it tereni  elect  rode  to  be  applied  to  eit  her  fool  or  either  hand, 
and  enables  one  to  change  from  one  to  another  bv  movm.tr  the  wire  from 
<>:.<  bindinu'-post  on  top  of  the  table  to  another.  A  burning  feeling  in 
t  he  fool  or  ha  inl  at  t  lie  indifferent  elect  rode  is  an  indie  at  ion  for  chan.innir 
from  one  limb  to  allot  her.  but  before  t  his  is  done  t  he  current  is  gradually 
•••(I  to  zero.  The  current  is  gradually  increased  to  the  original 
-'. ••«!.'_!  h  after  the  new  connection  has  been  made.  For  the  heaviest 
t~  three  oi  the  trays  may  lie  connected  with  the  negative  pole  of 
the  Lialvaiiic  current .  the  more  extended  suriace  of  contact  with  three 
ni  e.xin  tn  ties  ;il  the  same  nine  preventing  any  discomfort  from 
tiie  indifferent  electrode.  This,  however,  does  not  lessen  the  painful 
effei-i  at  i  he  active  electrode,  and  an  anesthetic  is  required  m  some 
ca-f-.  a-  ill  the  u-e  of  ;i  metallic  /me  electrode  of  small  si/e  covered 
•  '•;.••  •  ;  •  '  it  h  a  5  per  cetit .  solution  of  /.inc  sulphate  and  a  current  of 
}i  i  to  ^'  i  ma.  for  the  cure  of  roth -i it  ulcer.  \\  eaker  currents  ma\'  be  used 
!o!'  t  •  \\  it  I io ul  an  a  in'- 1  he;  ic. 

Adrenalin  cataphoresis  i-  used  as  a  means  of  blanching  the  tissues 

•    Mon  ol  t  he  nil  ra violet  rav.  which  \\'ill  not  penet  rat  e 

:  blood.      A  <mall  electrode  is  used,  which  terminates 

ii  reci -pi  a de.  for  1  he  sol  111  ion  ( 1  :  1000  adrenalin  chlorid), 

•.•••••''  •       -   formed  ol    porous   membrane.      This  is  the 

•  1 1  i -i  rode.      The  ot  her  elect  rode  may  be  held  in  t  he  hand, 

fill    of  about    ."i   ma.   be  allowed   to   flow   for  about 


Mercuric  Cataphoresis.     This  term  is  u-ually  applietl  to  t  he  met  hod 

Ma-      '.',      I'.xtremelv  heavy  current-^  of  about    |l)(l  ma.  or 

•    po    i  ive  eli'd  rode,  consist  in»-  of  .-harp 

a'e.l   with  merciirv.  thrust   into  the  tissues  while 

.  •  • .    •     •    n      ai  i\e  elect  rode.      A   general 

I  :  •  '<      -    coaiMiiat  ion    necro-i-    or   add    necrosis 


IONIC    MEDICATION    BY    ELECTROLYSIS  403 

of  the  tissues  for  almost  \  inch  around  each  metal  point  connected 
with  the  positive  pole,  and  the  portion  of  tissue  thus  destroyed  dries  up, 
and  eventually,  after  one  or  more  weeks,  separates,  leaving  a  granulating 
surface. 

Correct  technic  is  extremely  important.  The  indifferent  negative 
electrode  had  better  be  a  pad  of  kaolin  laid  over  a  smaller  sheet  of  metal, 
which  it  more  than  covers.  Any  small  area  of  metallic  contact  or  mark- 
edly greater  conductivity  would  permit  a  more  concentrated  flow  of 
the  current,  and  produce,  at  the  indifferent  electrode,  a  negative  burn, 
which  is  characterized  by  alkali  necrosis  or  colliquat  ive  necrosis  — 
a  moist  gangrenous  process  like  that  produced  by  the  action  of  a  caustic 
alkali.  The  patient  is  under  the  influence  of  an  anesthetic,  and  so 
cannot  give  warning  of  the  occurrence  of  a  burn.  The  positive  wire 
may  be  divided  into  about  five  strands,  and  it  is  best  for  the  zinc 
points  (pieces  of  sheet  zinc,  such  as  signs  are  painted  on.  about  \  of 
an  inch  wide  at  the  base,  about  o  inches  long,  and  tapering  to  a  very 
sharp  point)  to  be  soldered  to  the  copper  wires.  If  this  is  inconvenient, 
they  may  be  b:'iit  around  the  wire  and  securely  pinched.  The  points 
are  galvanized  by  dipping  them  first  in  dilute  acid  and  then  in  metallic 
mercury.  The  first  point  should  be  introduced  before  the  current  is 
turned  on.  and  a  rheostat  should  be  used  to  very  gradually  increase 
the  strength  of  the  current  from  zero  to  .'•>()  or  40  ma.  Then  another 
point  is  gradually  introduced,  and  it  will  be  found  that  the  milliam- 
peremeter  registers  an  increased  current,  due  to  the  larger  area  of  contact. 
Other  points  are  introduced  so  as  to  transfix  the  tissues  all  around,  and, 
if  practicable,  beneath  the  growth.  The  current  may  then  be  found  to  be 
.">()  or  (iO  ma.,  the  increased  area  of  contact  at  the  metal  points  having 
greatly  reduced  the  resistance  at  the  positive  pole,  while  the  resistance 
at  the  negative  pole  has  not  been  changed.  Additional  current  is  now 
turned  on  very  gradually  until  100  or  even  200  ma.  are  indicated  by  the 
milliamperemet  er.  The  flesh  is  seen  to  turn  white,  and  a  white  froth 
exud-'s  from  the  different  punctures.  The  exact  length  of  time  that  the 
current  should  be  allowed  to  flow  varies  with  the  amount  of  tissue  that 
is  to  be  destroyed.  It  is  usually  between  five  and  ten  minute-.  The 
current  must  be  turned  off  just  as  gradually  as  it  has  been  turned  on. 
and  the  last  metal  point  must  not  be  removed  until  the  current  has 
ceased  to  flow.  The  110-volt  direct  current  is  most  suitable  for  the 
work.  This  may  be  obtained  from  the  direct  110-volt  electric-light 
circuit,  or  from  the  alternating  electric-light  circuit,  by  a  rotary  trans- 
former or  a  storage-battery  or  a  galvanic  battery  of  the  necessary 
number  of  cells  to  produce  about  110  volts  may  be  used.  A  motor 
dynamo,  giving  either  alternating  or  direct  current  of  2  amperes  and  110 
volts,  costs  Si).")  and  is  invaluable  for  direct  current  work  when  the 
electric-light  current  is  alternating.  (iood  dispersing  pads  are  es- 
sential and  they  must  be  sufficiently  moist.  If  metal  is  too  near  the 
patient,  pain  limits  the  strength  of  current  the  patient  can  stand. 

Shocks  from  poor  or  rusted  connections  limit  it.  Massey  avoids 
this  trouble  by  using  cotton-covered  magnet  wire  No.  ;->2  or  oO.  fresh 
lengths  each  time,  and  if  the  apparatus  has  not  spring  catches,  put  in  a 
match  stick  with  the  wire  in  the  binding-post. 

This  treatment  has  been  applied  to  cancers  of'  the  breast  and  tongue, 
localities  where  turning  the  current  on  or  off  suddenly  would  cause 
serious  shock. 


The  advantages  ot  this  treatment  are  the  Ireedom  troin  hemorrhage, 
the  mmplrtf  dcst  met  ion  of  the  part  to  which  it  is  applied,  the  presence 
of  a  -terili/ed  and  u-ually  i||-y  sloiiiih.  which  changes  into  a  dry  seal) 
and  come-  away  l>\  natural  proce-se>. 

The  disadvantages  are  that  it  does  not  have  a  selective  action  upon 
t  he  inorl  iid  I  issue,  nor  one  extending  1  icyond  1  he  area  act  ually  dest  roved, 
and  t  hat  it  -  ci  cat  rices  a  re  very  1  >ad  compare)  I  with  1  hose  let  t  a  1 1  er  a  case 
ha-  been  cured  tiy  the  .r-ray  or  liy  suruical  removal  and  a  plastic  opera- 
t  ii  in. 

While  the  method  i-  certainly  a  valuable  one  for  use  in  occasional 
-pecial  cases,  it  may  not  lie  unfair  to  characterize  it  in  some  other  cases 
a-  an  imperirci  lorm  ot  suru'cry.  There  is  a  (|iiestion  as  to  whether 
the  destructive  effect  is  at  all  due  to  the  transportation  of  mercury  into 


ha-    iieeii    used    iii   cancer  of  the  neck  of  the   uterus,  as 
'Aell  M-  ii     e\i     ma  I   '_L  rowt  h-.   li  ke  t  hosi     nielli  ioiicd  a  1  )OVc. 

cancer    nodules    in    the     hreasl     Massev'   dest  rovs    the 
'lie  axillary  content-  iiy  a  liipolar  ioni/ation  of  1S(K)  to 

ianc\  of  a  lump  in  the  hreasl  by  fa radie  current  which 
[lainlul  area-  of  chronic  mastitis.      Anv   nodule 
•   week<    daily   laradixat  ;on   i.-  either  a   cvstoma, 
and    is   to   he  de.-t  roved. 

-'I 


IONIC    MKDICATION     MY     KLKCTKI  >LYSIS 

Cocainization  by  Cataphoresis.-  The  most  successful  method  is 
to  moisten  the  felt  covering  of  the  positive  electrode  with  a  10  per  cent, 
solution  of  cocain  hydrochlorid  in  guaiacol,  and  to  apply  a  currenl  of 
f>  ma.  for  about  five  minutes.  This  produces  cutaneous  anesthesia,  but 
a  doubt  remains  in  the  author's  mind  as  to  whether  il  is  any  greater 
than  would  be  accounted  for  by  the  action  of  the  guaiucol  (a  carbolic- 
acid  derivative)  without  an  electric  current.  The  method  has  been 
employed  for  neuralgia,  for  the  pain  in  locomotor  at axia,  and  as  a  prepa- 
ration for  small  superficial  operations. 

Fig;.  2S(i  shows  a  suitable  volt   controller  for  dental  cataphoresis. 

Electrolytic  Medication  in  Middle-ear  Disease.  The  materials 
employed  by  Malherbe1  are  solutions  of  sodium  chlorid.  potassium  or 
sodium  iodid,  and  pilocarpin  nitrate.  The  strength  of  the  solutions 
varies  from  '2  to  o  per  cent .  and  the  act  ive  elect  rode  ( posit i\'e  wit  h  the  first 
three  substances  and  negative  with  pilocarpin)  consists  of  a  pledget  of 
cot  1  on  wet  wit  h  the  solution,  and  placed  in  I  he  external  auditory  meat  us 
in  contact  with  the  outer  surface  of  the  drum  of  the  ear.  The  other 
electrode  is  an  olive-shaped  one  with  an  insulated  stem,  and  is  intro- 
duced through  the  Kustachian  tube  until  it  touches  the  inner  sur- 
face of  t  he  drum  membrane.  Rather  strong  constant  currents  of  1  to 
o  ma.  are  used  for  seven  or  eight  minutes  three  times  a  week.  There  is 
a  feeling  of  warmth  or  of  burning.  There  is  a  beneficial  effect  upon 
sclerotic  and  cicatricial  conditions. 

Malherbe  has  treated  tubal  catarrh  in  the  same  way.  having  the 
anode  in  the  external  auditor}'  meat  us  wet  with  a  1  percent,  solution  of 
tine  chlorid  and  the  cathode  in  the  Kustachian  tube. 

Chlorin  lonization  for  Fibrous  Ankylosis,  Sclerosis,  Dupuy- 
tren's  Contraction,  Sclerodactylia,  etc.  The  benefit  which  has  long 
been  known  to  follow  the  application  of  the  constant  current  in  these 
cases  may  be  due  in  part  to  chlorin  ions  from  the  salt  solution  often  used 
to  moisten  the  electrodes.  The  specific  object  of  applying  these  ions 
requires  that  the  active1  electrode  should  be  a  large  one.  so  as  to  permit 
of  the  use  of  strong  currents  of  20  to  o()  ma.  and  that  it  should  be  the 
negat  ive  electrode. 

Copper  Electrolysis  for  Ring-worm.  -This  is  a  practicable  method, 
but  has  not  been  employed  to  any  extent.  The  object  is  to  carry  an 
antiseptic  agent  into  the  hair-follicles.  The  strength  of  current  depends 
upon  the  area  of  contact:  the  application  should  not  be  strong  enough 
or  long  enough  to  cause  pain,  but  it  must  cause  a  distinct  sense  of 
warmt  h. 

Copper  Cataphoresis  for  Fistulas  About  the  Jaw.  A  suggestion 
by  the  author  is  to  make  use  of  copper  electrolysis  for  these  cases,  after 
making  sure  that  there  is  no  retained  broken  root  or  root  filling.  A 
small  area  ol  necrosis  can  be  cured  by  this  means.  The  current  should 
be  (>  ma.,  or  as  near  that  strength  as  the  patient  can  stand.  The  po<i- 
tive  electrode  is  a  pure  copper  rod  introduced  into  the  fistula,  and  the 
negative  electrode  is  applied  at  some  indifferent  place. 

Iontophoresis  for  Sterilizing  the  Root  Canals  of  Teeth.-  ( 'hlorin  ions 
may  be  liberated  from  a  1  per  cent,  salt  solution  which  fills  the  root 
canal.  The  positive  electrode,  an  indoplat  mum  needle,  extends  through 
this  to  the  apical  foramen  while  the  patient  holds  the  negative  electrode 
in  one  hand:  no  rings  or  bracelets  are  worn.  A  constant  current  of 
1  . \roli.  d'Klect.  mod.,  .Ink  10.  1907. 


40(1  MF.mCAL    KLKCTKICITY    AND    KOXTdEX    RAYS 

:\()  to  10  volts  is  irradually  increased  from  zero  until  the  patient  first 
notice-  even  the  slightest  sensation.  Then  it  is  slightly  reduced  and 
allowed  to  tiow  for  thirty  seconds.  Then  it  is  increased  until  there  is 
sensation  or  until  the  irritation  point  is  found.  Prin/'s1  idea  is  to  find 
in  tin-  way  the  urea  test  strength  of  current  which  can  lie  applied  con- 
linuously  without  producing  irritation.  The  length  of  time  for  which 
thi-  maximum  current  is  to  lie  applied  is  thirty  minutes  divided  by  the 
number  of  milliampetvs.  For  example  each  root  canal  of  a  certain  tooth 
may  require  '2  ma.  for  fifteen  minutes.  All  metal  fillings  must  he  re- 
moved frm n  a  tout  h  bein<>;  sterilized  in  this  way.  If  not,  there  is  danger 
of  -hock  and  al-o  of  the  tooth  being  discolored. 

Copper    Cataphoresis    for    Infected    Punctured    Wounds    with 

Chronic    Fistulas.      A    copper    positive    electrode    is    passed    into    the 

ti-tula.  and  a  current  of  i>  or  s  milliamperes  is  allowed  to  flow  for  six  or 

lies,    when    the   current    is    irradually    reduced   and   a    reverse 

current  of  _'  or  '•>  ma.  i-  allowed  to  flow  for  a  short  time  to  loosen  theelec- 

.  the  flesh.      Treatments  are  u'iven  once  a  week,  and  result  in 

a   cU!'f   111    t  lll'ee  or   toll!'   weeks. 

Magnesium   lonization   for   Flat  Warts.      A   piece  of  absorbent 

iti  in  _'  cm.  in  thickness  and  with  a  surface  of  ]()()  cm.  was  moistened 

•\  it  h  a  .")  per  cent,  -oli n  ion  of  magnesium  sulphate  and  formed  t  he  posi- 

live  electrode.      A  current   of   10  ma.  was  applied  for  fifteen  minutes. 

I ...  •  '  days  ;t  ft  er  the  first  t  reat  m  en  t  the  skin  was  smoot  h.  and  over  almost 

lie    surface    treated    the    warts    had    become    flattened    and    effaced. 

Some  disappeared  without   leaving  any  trace.      Most  of  them,  however. 

were   leplaced   by   a   little  yellowish-brown  spot :  others  felt    a   little  bit 

roiiirh.     <  >nly  two  t  r<  at  ments  were  required  at  intervals  of  eiVht  days. 

and  five  or  six  days  after  the  last  treatment  the  skin  was  entirely  normal. 

Tin--  i-  the  hi-tory  of  a  case  of  multiple  verruca  ])lanus  of  the  face. 

•  •   ited  in  ilu-  way  by  Bordet .  after  all  the  usual  methods  of  treatment 
h:    :   failed,  aiifl  even  after  t  he  application  of  high-frequency  sparks  had 
produced  linle  effect. 

Magnesium   lonization   in   Fungating  Warts.      A   case  in  which 
'!''-    treatment     was    tried    by    Bordet    did    not    yield    promptly.      The 

•  •  •'•    •;••  measured  Of)  sq.  cm.,  and  a  current  of  15  ma.  was  applied  for 

Seven   or  ei^ht    small    flat    warts   disa]ipeared   in   the 
•'•   three  treat  men  Is.  but   t  he  fungal  hm  ones  were  so  lit  t  le 
'    IK- destroyed  them  by  t  lie  galvanocauterv. 

lodin  Anaphoresis  for  Goiter.      A  solution  of  potassium  iodid  or 

din  iii  one  o]   pota.-sium  iodid  i-  used  to  moisten  the  felt 

ive  ele<-troile.       I  he  process  is  one  of  aiiaphoresis.  not 

•  -1     '  he   active   atrent    i-   one    \\-hich   seeks    the   anode 

1  he    electrode    mil-!     be    a    lai'LTe    one.    curved 

ectrode  i-  a   hirji'e  one.  and   is  placed  at   some 
i!ai    care   must    be   exercised    in    t  urm'tm'   t  his 

ni    on    and   oil    gradually.       Ajmlicat  ions    are 

!'i    ' ) Hit  e  painful. 
'  •'  seldom  cause-  t  he  com  pi  et  e  disappearance 

•  pM-.-ili    that    it    ma;    be  due  practicallv  entireh"  to 

'-    '   llTenl    and    :.   H    Iii  I  he  iodin. 

lodin  Anaphoresis  for  Chronic  Suppurative  Adenitis.     A    metho.l 
!)•  in  :i  '  '.I-IMII-,  April.   I'.MT 


IONIC    MEDICATION    BY    ELECTROLYSIS  40 1 

which  is  useful  in  cases  where  it  is  very  desirable  to  avoid  an  incision 
and  consequent  scar  is  by  aspiration  of  the  pus,  injection  of  a  solution  of 
iodin  or  iodid  of  potassium,  and  introducing  a  needle,  insulated  except 
at  the  point,  and  connected  with  the  negative  pole  of  the  battery. 
The  other  electrode  is  applied  at  some  indifferent  place.  A  current  of 
10  or  1")  ma.  is  gradually  turned  on  and  allowed  to  flow  for  ten  minutes. 
Three  or  four  applications  usually  effect  a  cure. 

Iodin  lonization  for  Gonorrheal  and  Tabetic  Arthritis  of  the  Knee. 
Successful  cases  have  been  reported  by  (iiovine.1  A  solution  of  pr- 
tassium  iodid  is  used  to  moisten  the  large  negative  electrode  which 
is  wrapped  around  the  joint. 

Acute  tonsillitis  may  be  treated  by  a  padded  electrode  at  the  back 
of  the  neck,  and  a  probe  wrapped  in  cotton  wet  with  o  per  cent,  zinc 
iodid.  A  galvanic  current  of  15  to  20  ma.  is  applied  to  the  tonsils  for 
five  or  ten  minutes.  Kesteven  says  that  pain  is  quickly  relieved  and 
the  swelling  reduced  in  forty-eight  hours,  two  or  three  applications  usu- 
ally sufficing.  Chronic  indurated  cases  require  a  10  per  cent,  solution 
and  eight  or  ten  treatments,  three  each  week.  The  negative  pole  is 
applied  1o  the  tonsils,  as  iodin  is  an  anion. 

Hypertrophied  turbinated  bones  are  treated  by  ionizalion  with  a  2 
per  cent,  zinc  iodid  solution,  two  or  three  minutes  at  a  time.  Smarting 
is  allayed  by  a  carbolized  powder  (Kesteven). 

Zinc  Cataphoresis  for  Fistula  in  Ano. --These  cases  have  always 
been  extremelv  difficult  to  cure  by  this  met  hod.  but  an  improved  technic 
suggested  by  Bilinkin  has  resulted  in  a  number  of  cases  being  cured. 
The  positive  electrode  consists  of  the  finest  kind  of  a  zinc  rod  or  needle, 
and  it  is  coated  with  paraffin  except  for  1  cm.  at  its  distal  extremity. 
It  is  introduced  to  the  bottom  of  the  fistula,  almost  but  not  quite 
entering  the  rectum.  A  current  of  6  ma.  flows  for  three  minutes,  and 
the  bowels  are  kept  constipated  for  three  days  by  means  of  opium.  At 
subsequent  treatments  the  electrode  does  not  pass  so  far  into  the  fistula, 
and  the  strength  of  the  current  is  gradually  reduced.  From  six  to 
twenty  treatments  are  required  to  effect  a  cure.  It  is  most  likely  to  suc- 
ceed in  cases  where  the  patient  is  strong  and  has  no  tuberculous  trouble. 
It  may  do  considerable  good,  however,  even  in  tuberculous  fistulas. 

Zinc  lonization  for  Epithelioma.— The  best  solution  is  1  per  cent, 
chlorid  of  zinc.  Leduc  uses  a  current  of  2  ma.  per  square  centimeter 
of  surface  to  be  treated,  and  an  application  lasting  fifteen  or  twenty 
minutes.  Lewis  Jones  uses  much  stronger  currents,  but  still  quite 
endurable,  and  a  shorter  application.  Cocain  may  lie  required,  but  not 
a  general  anesthetic.  A  zinc  electrode  is  used,  and  cotton  wet  with 
the  solution  may  be  lied  around  the  <;lectrode  or  simply  laid  upon  1  lie 
ulcerated  surface.  The  effect  of  an  application  of  10  ma.  for  ten  min- 
utes is  to  impregnate  the  superficial  tissues  with  zinc  ions  and  to  turn 
them  a  dead-white  color,  which,  however,  does  not  indicate1  necrosis.  A 
little  later  the  surface  becomes  red  and  remains  somewhat  inflamed  for  a 
week.  Soothing  applications  are  required,  and  no  further  electrolysis 
probably  until  two  or  three  weeks  after  the  first  application.  Two  or 
three  applications  are  required. 

Zinc    Electrolytic     Medication    in    Gonorrhea.  —  A    soft-rubber 
catheter  with  multiple  eyelets  is  used  to  irrigate  the  urethra  with  somo 
solution,  such  as  \  per  cent,  solution  of  sulphate  of  zinc,  which  form-* 
1  Kiformn  Milieu.  November  2.  1907. 


(IIS  MK1MCAL    Kt.KeTKK   1TY     AND    KONTGKN     HAYS 

the  positive  electrode  for  a  current  of  from  1  to  10  inn.    Bouchot1  makes 

the  electric  connection  with  the  liquid  l>y  the  use  of  a  fine  platinum  wire, 
which  paxes  through  almost  the  entire  length  of  the  catheter,  and  which 
is  fastened  to  a  metal  tul>e  inserted  between  the  tube  from  the  irrigator 
ban  and  the  catheter.  It  i-  to  this  metal  tube  that  the  positive  wire  is 
secured.  The  other  electrode  is  applied  to  any  other  indifferent  region. 
An  irrigation  with  '_'  quails  of  solution  is  enough  for  each  application. 
In  acute  crises,  \\here  the  treatment  is  begun  on  the  iirst  or  second  day 
of  the  disease.  Boiichet  lias  found  that  daily  treatments  cause  immediate 
disappearance  of  the  discharge  and  sterili/e  the  urethra  of  gonocoeci  in 
fourteen  days.  In  :'>0  chronic  cases  he  obtained  a  complete  cure  in  three 
or  four  weeks  bv  applications  made  every  other  day. 

Hi!--,  of  London,  recommend-  the  treatment  of  gonorrhea  by  the 
direct  continuous  current  by  a  stylet  encased  in  a  rubber  tube  with  per- 
forations at  MS  distal  end  and  filled  with  a  very  low  percentage  of  silver 
salt  and  iodin:  the  current  is  first  in  one  direction  and  then  in  the  other. 
Ma-svy'  stllvu-(.sts  a  copper  stylet  and  1  per  cent,  copper  sulphate. 

Zinc  Cataphoresis  for  Alopecia.  LeducV  experiments  upon 
rabbits  rendered  bald  bv  tinea  show  that  the  application  of  a  positive 
electrode  wet  with  a  1  per  cent,  solution  of  chlorid  of  zinc  causes  rapid 
irri  >'.'.  t  h  of  the  hail1. 

Chronic  Hemorrhagic  Endometritis  and  Chronic  Ulcer  of  the 
Leg.  Xnic  cataphoresis  is  excellent  in  both  these  conditions. 

Lithium  lonization  in  Gout,  (iuillo/'s  method  has  been  used 
success!  nllv  in  a  lame  number  of  cases  (70  ot  his  own  reported).  The 
atTected  limb  rests  in  a  porcelain  basin  filled  with  a  '_'  per  cent,  solution 
ot  a  In  ii m m  salt  .  wit  h  enough  lithium  hydrate  to  alkalim/.e  it .  The  posi- 
tive  electrode  i>  placed  in  the  solution,  and  a  large  indifferent  negative 
electrode  i-  applied  over  the  lumbar  region,  (iiiillox  graduallv  turns 
on  a  current  of  1  .">(  >  or  L'OO  ma.,  and  allows  t  his  to  flow  for  t  went}'  or  thirty 
minutes,  lie  terminates  the  session  by  fifteen  minutes'  high-frequency 
aii'ocondiict  ion.  I'reatments  are  Driven  ever\'  da\'  or  perhaps  twice  a 
day. 

I'he   re-ults   are   relief  of  the  local   symptoms,   a   rapid   reduction   in 

•Aeiiiln.    a    cure   of   the   attack,    and    prophylaxis   against    other  attacks. 

1  i'liitv  deposits  often  disappear.       It   must  be  remembered  t  hat  these  are 

heavy  currents.  In  be  applied  for  such  a  length  of  time. 

;  t  he  u.siial  care  mu-t  be  taken  '  o  prevent  shocks  or  burns. 

Bipolar    hiidi-l  reqiiencv    e|Iiu\  ia !  1011    ma\'    be    substituted    for    auto- 

•'  ioli   in  t  he  above  techllic.       f'.lect  ric-1  i'_:hl    bat  hs  are  of  Verv  irreat 

n    '     ca-e-    \\here   catMphoresis   and    high-frequency   currents 

I'"1     .          '          toimd    uric    acid    in    the    -olutioli    \\ith    \\hich    the    posi- 

uei     durniL:     lithium    cat  a  jihoresis.        nipping    the 

•    .'     'i      il    a    sail    ot    lithium,   uhii'h    forms   I  he  anode,  lithium 

be    (ia  ri   •         •  1 1!   the  -\  -'  en  i    1  >\    the  r  u  r  re  nt  .   and   will    a  p  pear    in    the 

illld    be   Used    |f    il     l-    desifeil    to    \\)\  ]>  iduce   1  he   acid 


IONIC     M  INDICATION     I',V     KI.KCTKOl.YSIS  409 

solution  of  lithium   (-blond,   \vilb    about    ,,,-'„„   of  litbiuin   hydrate,  just 
enough  to  render  tbc  solution  alkaline. 

I  ric  acid  is  a  great  many  tunes  more  soluble  in  a  solution  of  a 
lithium  salt  than  in  the  normal  fluids  of  the  body,  and  this  is  the  theory 
of  t  his  applieal  ion. 

Salicylic  lonization  in  Acute  Rheumatism.  A  4  per  cent, 
solution  ot  sodium  sabcylate  mav  be  used  to  moisten  the  negative 
electrode,  and  a  current  of  from  .">  to  !.">  ma.,  depending  upon  the  si/e 
of  the  electrode,  may  be  applied  for  half  an  hour  to  an  hour.  Bordet' 
reports  the  cure  ot  a  case  ot  talalgia  ]>v  three  treatments;  of  a  case  of 
tendinous  articular  rheumatism  by  ten  treatments;  of  a  case  of  acute 
muscular  rheumatism  by  se\-en  treatments;  and  of  a  case  of  acute 
polyarticular  rheuniati.su]  by  nine  treatments. 

Salicylic  lonization  in  Migraine  of  the  Arthritic  Diathesis. 
According  to  Hartenberg,"  an  attack  of  sick  headache  in  these  cases  is 
due  to  arterial  spasm,  probably  from  irritation  of  the  cervical  sympa- 
thetic, and  this  he  considers  due  to  a  rheumat  ic  infiltration  of  the  tissues, 
especially  the  muscles  ot  the  neck.  Parts  of  the  muscles  are  sxvollen 
and  lender.  If  the  swelling  is  recent  and  subacute,  it  is  elastic  and 
supple,  but  if  it  is  inveterate,  there  are  hard  nodules  in  the  muscles. 
There  may  also  be  indurated  glands,  thickening,  and  infiltration  of  the 
skin.  This  condition  irritates  the  superior  cervical  ganglion  of  the 
sympathetic,  which  becomes  sensitive  to  pressure.  Electrotherapy, 
xvhich  removes  these  infiltrations,  cures  the  sick  headaches. 

Salicylic  ioni/at  ion  is  employed.  The  negative  electrode  is  placed 
around  the  neck,  and  is  moistened  with  a  "20  per  cent,  solution  of  so- 
dium salicylate.  The  positive  electrode  is  at  some  indifferent  place.  A 
current  of  from  15  to  ;">()  ma.,  according  to  the  si/e  ot  the  electrodes,  is 
allowed  to  floxv  for  one-half  hour.  Kecent  muscular  swellings  disappear 
in  twenty  treatments.  The  harder  ones  take  a  longer  lime,  but  disap- 
pear with  the  glandular  and  cutaneous  infiltrations.  The  sick  headaches 
are  benefited  during  the  first  month,  and  are  cured,  but  occasional 
treatments  are  desirable  to  prevent  relapse. 

Salicylic  lonization  for  Muscular  Rheumatism  in  the  Lumbar 
Region.— Each  electrode  measures  0  by  S  inches  and  the  negative 
electrode  is  wet  with  a  4  per  cent,  solution  of  sodium  salicylate.  and 
placed  at  the  seat  of  the  greatest  pain.  The  other  electrode  is  placed  a 
few  inches  away,  either  above  or  below.  A  current  of  from  .")()  to  SO 
ma.  is  u'raduallv  turned  on,  and  allowed  to  floxv  for  from  fifteen  to  sixtv 


Salicylic     lonization  for    Sacrovertebral     and    Sacrococcygeal 

Arthritis.  This  has  been  successfully  employed  by  Border1  in  cases  ot 
such  severity  that  the  patient  was  confined  to  bed.  The  negative 
electrode  is  wet  xvith  a  4  per  cent,  solution  of  sodium  salicylate.  and  is 
applied  over  the  painful  articulation,  xvlule  the  other  electrode  is  at 
a  point  near  the  spine,  a  few  inches  higher.  A  current  of  .'!()  or  40  ma. 
for  about  txventy  minutes  every  day  is  required,  and  each  treatment 
max  be  terminated  by  faradization  xvith  a  fine  wire  coil  and  a  moderate 
strength  of  current  applied  bx  a  roller  electrode. 

Salicylic  lonization  for  Tic  Douloureux.     This  has  been  used   by 


4in 


I.edue'1  and  others  with  a  certain  proportion  of  euros.  The  negative 
electrode  i.-  a  sheet  ot'  metal  conformed  to  the  shape  ot'  the  portion  of  the 
face  affected,  and  covered  with  absorbent  cotton  wet  with  a  solution  of 
-odium  salicvlate.  A  cunviii  of  about  'Jo  ma.  is  allowed  to  fiow_  for 
about  an  hour.  The  process  i-  the  reverse  of  cat aphoresis.  tlie  ions 
desired  hein-:  the  acid  ions  which  (low  away  from  the  cathode,  and  not 
toward  it.  The  indifferent  electrode  must  be  a  laruo  one  to  prevent 
m  such  a  strength  of  current  for  so  lorn:  a  tinic^  One 
or  ,,„„-,,  ,,i  tlu.  n-lls  ,,i  a  tour-cell  bath  serve  admirably  as  the  indifferent 
electrode. 

INDICATIONS    F<>R    K  )NT(  >PIK  >RKS1S  >  M<ic!,ii<io's  Table).2 


>J  (_  Zinc  iuntophore-is. 

Secondary   infections  of     Zii/_-  iontophoresis. 

ec/enia    or    oilier    se-  |  Cathode  of  amalgamated  zinc, 
creting  dermatoses.       | 

Sluggish  wounds. 

Fpithelioniata. 

Acne. 

Furuncle  and  anthrax. 

Alopecia  areata. 

Falling  of  hair. 

Sycosis. 

Tinea. 

Fistula-. 
!  \ erniga. 
ffiollt. 


Recjuircs    a    ficneral  anesthetic, 
and  .r-ray  is  better. 

Zinc  iontophoresis. 
( 'opper  iontophoresis. 
( 'opper  iontophoresis. 
Magnesium  iontophoresis. 


(  Salicylic  iontophoresis. 
loilin  iontophoresis. 
I-'.lectrolvtic  baths. 
1  CM.  Am.'.  CM  Li.      KI.    Ns,S,( ).. 

iontophoresis. 
Blennorrhagic    rheuma-  |  Salicylic  iontophoresis. 

tisni. 

I  Fibroii:- anchylosis.  I  I<>din  iontophoresis. 

|  Quinm  iontophoresis. 

1  -.m  jtimin  iontophoresis. 
.  Cocain    and  guaiacol   iontopho- 

resis. 

Salicylic  ionto])horesis. 
Zinc  anode  iontophoresis. 

lilennorrhatiic  urethriti-.  /me  anode  iontophoresis. 
Blennorrhaiiic    urethriti-.  gelatin     liuuuie    anode    impreg- 
nate' 1   wit  h   nitrate  i  if  silver. 

lodin    iontophoresis. 
|   \on--uppurat  ive  ;ii  |enit  i<. 

tiun-..          Suppurat  ive  adcnit  is  inject  ion  of  K  I  -olution,  with  evacu- 
I        ated   -a'1  .-ill- 1   then  galvanic  current . 

i    \nude  -u! ut  PHI  •_'  to  .",  per  cent.  Na<  '1,  KC1.  ur  I\F 

i  (  'MI  hi  pile  ~i  >!i it  inn  _'  tu  ."i  per  cent .  pilocurpiii  nitrate. 

Ionic    Medication    by    Means    of    High-frequency    Currents.—  An 

p  irpo-e    Kie..  'Js?    eon<i.-t<  of  a  dome-shaped  unipolar 

vacimm  tube  with  a  le;,dinir-in  wire,  which  terminate-  le--  than  an  inch 

from  the  Hat   -urface  whicli  i-  to  1  PC  applied  to  t  he  bod\-.      Thi-  leading-ill 

''..•:>•    i-    i-diiiieeted    \^ith    the   <>udin    resonator   or   with    one   pole   of   the 


IONIC    MEDICATION    BY    ELECTROLYSIS  41 1 

d'Arsonval  transformer.  In  the  latter  ease  the  patient  holds  a  metallic 
electrode  connected  with  the  other  pole.  The  flat  surface  has  a  recess 
in  which  is  fixed  a  sheet  of  asbestos  moistened  with  the  medicine  to  he 
employed.  There  is  certainly  some  effect  upon  the  skin  from  the  vapor- 
ization of  the  medicine  by  the  shower  of  sparks  employed,  but  it  seems  ex- 
tremely doubtful  whether  any  effective  amount  of  the  medicine  is  carried 
into  the  tissiu>s  by  the  currents.  High-frequency  currents  are  alternat- 
ing, and  one  of  the  primary  conditions  of  cataphoresis,  electrolysis,  and 
polarization  is  a  unidirectional  character  to  the  current.  When  one 
wishes  to  prevent  electrolysis  and  the  like,  the  first  step  taken  is  always 


Fii;.  2s7. — Electrode  for  ionic  medication  by  means  of  high-frequency  currents. 

to  make  the  current  an  alternating  one.  The  effect  of  iodin  upon  the 
skin  is,  however,  very  much  increased  by  this  application. 

Chlorin  Iontophoresis  in  Rheumatoid  Arthritis.-  Where  there  is  a 
boggy  swelling  around  the  joint  wrap  joint  with  twenty  thicknesses  of 
lint  wet  with  a  sterile  2  per  cent,  salt  solution.  Tin-foil  and  oiled  silk 
are  outside  of  this,  which  forms  the  negative  galvanic  electrode.  The 
positive  indifferent  electrode  should  have  a  larger  area.  The  density  of 
the  current  should  be  not  more  than  1  ma.  per  square  centimeter. 
This  is  applied  thirty  minute's  three  times  a  week.  It  may  free  the 
ankylosis.1  A  finger-ring  should  not  be  worn  because  of  possible  con- 
centration of  the  current:  in  fact,  Humphris  reports  a  burn  under  a 
finger-ring  from  25  ma.  for  thirty  minutes. 

Various  Opinions  as  to  the  Value  of  Electric  Ionic  Medication.— 
Ziinmenr  believes  that  there  is  nothing  but  a  surface  effect  from  the 
ions  of  medicinal  substances  which  are  used  to  moisten  the  electrodes, 
and  that  the  deep  effects,  beneficial  or  otherwise,  are  due  to  the  current 
itself.  The  last  clause  means,  of  course,  the  tissue  ions  which  transmit 
the  current,  and  which  in  reality  constitute  the  current. 

Iscovesco  and  Matza:t  have  performed  experiments  in  which  they 
tested  the  electrolytic  introduction  of  medicinal  substances  into  gelatin 
containing  ,';,  per  cent,  common  salt,  and  found  only  a  surface  action 
with  potassium  permanganate.  A  layer  was  produced  upon  the  sur- 
face which  prevented  further  progress  of  the  colored  particles.  The 
result  with  copper  sulphate  was  the  formation  of  copper  chlond.  which 
penetrated  into  the  gelatin  at  the  rate  of  1  cm.  (0.4  inch)  in  several 
hours.  The  result  with  iron  acetate  was  the  same  as  that  with  potas- 
sium permanganate. 

Their  conclusion  is  that  it  would  be  more  effective  to  give  a  hypo- 
dermic injection  of  the  substance  to  be  introduced  into  the  living  body 
than  to  u.-e  the  elect rolvtic  method. 


412  MKDHAL    KLKCTKICITY     AND     KO.NTOKN     RAYS 

Tutiier  and  Matite  have  experimented  with  salicylic  ionixat ion, 
and  have  obtained  tlie  characeri.-t  ic  color  reaction-  in  the  most  super- 
ficial laver-  ni"  the  epidermis,  hut  never  in  the  subcutaneous  cellular 
tissue. 

Lat  teiix  and  Ximniern1  have  seen  part  ides  (if  copper  deposited  at  the 
surface  of  the  uterine  mucous  membrane  in  a  rabbit,  but  never  in  the 
deeper  I  issues. 

(iaUtl'elet  (December  _.">.  1!»<>7).  in  testing  the  effect  of  different 
met;  llic  ion-  upon  the  heart  in  fro^s.  drew  the  conclusion  that,  under 
tin  n-ual  conditions  of  electrolytic  medication  in  man.  the  ions  which 
are  int  n>d  need  form  combinations  with  other  ions,  and  produce  a  local 

•  '  •    •'.  but  do  not  enter  the  general  circulation. 

[•"ro^s   were   placed    with   one   hind    foot    in   a   solution  of  potassium 

•  hlorid.  iron  ch'.orid.  maLnesium  chlond.  etc.,  and  the  other  hind  foot  in 
a   _'  pi-r  cent.  -olution  ot   sodium  chlond.   while  a   current  oi    _'  ma.  was 

•  d  to  flow.  The  metallic  solution  was  connected  with  the  positive 
pole.  I  he  movements  of  t  he  denuded  heart  were  registered  by  a  .Ma rev's 
c;  rdi'  i^raph. 

ifi.-  conclusions  were  that  potassium,  mercury,  and  copper  ions 
art  essential  poisons  to  the  heart  muscle,  acting  onl\  sliiditlv  upon  the 
cardiai  nerves.  Magnesium  ion-  .-top  the  heart'-  action  by  an  effect 
••ipon  its  nerves.  Trivalenl  iron  ions  slightly  paralyze  the  heart  muscles, 
but  act  ::-  a  violent  poison  upon  the  nervous  system.  Divalent  iron 
ion-  and  calcium  ion.-  are  tonic-  of  the  cai'diac  muscles,  but  in  laru'e 

•  loses   ad    a-  a   nerve  poison.      Sodium   and   silver  ion-  do   not    produce 
much  effect,  although  the  iir-t  slightly  stimulates  the  myocardium,  and 
'he  latter  Cumulates  the  cardiac  nerves. 

HrtVard  •  has  not  succeeded  in  the  ionic  treatment  of  ankylosis 
of  the  lariM'  joint-.  even  it  of  traumatic  origin.  He  doe-  not  believe 
that  the  medicinal  -ubstaiice  is  carried  beyond  the  follicle-  in  the  skin, 
and  Chinks  that  whatever  effect  iV  obtained  in  joint  cases  is  due  to  the 
electric  current  and  not  to  substances  u.-ed  to  moisten  the  electrodes. 

.Iu~:  as  the  effect  of  ha-ic  or  cation-  i-  manifested  at  the'  po.-itive 
pole,  so  the  acid  or  an  ions  produce  t  heir  effect  at  t  he  negative  pole.  The 
soiution  oi  common  salt,  so(lium  chlond.  which  is  otten  employed  to 
nidi-ten  t  he  eject  rodes  for  ordinary  t  herapeut  ic  and  dia.u'iiost  ic  purpo.-es. 


an  ion-,  and  produce  t  heir  effect  upon  t  he  tissues  do-e  to  the  neLr;tt  ive  pole 

:  roni  \\  hie]    t  },(.\   -tart  on  their  pat  hs  toward  t  lie  posit  i\'e  jiole.      Xa-cent 

•    i-   n-pon-ible  for  part   of   the  irritation   produced  when  -odium 

i'  ion  i-  u-cd  to  moi.-t  en  t  lie  elect  ro(les.  and  u  hid  i  mav  be  pre- 

'.  •  •  '  •    ol  <o(lium  bicarbonate  solution  for  that  purpose. 

Electrolysis  in  Cancer.     Tumor-  of  any  considerable  si/.e  require 

\>       '".'.          .'•.'-  'ijijiln'il  u  itli  the  same  precaution-  as  de.-cnhed  under 

the    head    of    Mercuric    (  'ataphore-i-     p.   102   .   the  only  difference  being 

that    platinum  needle-   are  u-ually  employed,  and    that    it    has  been  cus- 

tomarv  to  a\'oid    the    po->ibility  of  -hock    by  u-iim  both   pole-  actively. 

I  i '     '  '        '    •  '  '  -  :   tin    po-it  ive  and  ne^a  t  r.  e  elect  rode-  are  t  hru-t   into  the 

i   u    '•      periphery  of  the  tumor.  an<l  a  current   of  iiu  to  so  ma.  is 

Thi-    bipolar   method    doe-    iK,t     -eciire    the   drv 

'  •  d     \\hen    1  he    different     needle-    are  all    connected 


IONIC     MKDICATION     BY     ELECTROLYSIS  413 

with  the  positive1  \viro,  ami  t  ho  indifferent  negative  electrode  is  a  large 
one  of  kaolin  or  clay.  A  general  anesthetic  is  required.  The  entire 
area  destroyed  comes  a\vav.  There  is  no  selective  action  upon  diseased 
tissues.  The  hoalthv  tissues  are  destroyed  as  \vell  as  the  morbid. 
There  is  no  effect  beyond  the  area  through  which  the  current  flows  in 
its  greatest  concent  rat  ion. 

The  Strength  of  Current  to  be  Employed  in  Electrolysis. 
The  effect  is  greatest  upon  the  portion  of  tissue  directly  in  contact 
with  the  electrode.  With  moderate  currents  it  varies  with  the  length 
of  time  during  which  the  current  flows  and  the  current  density,  and 
depends,  therefore,  upon  the  quantity  of  electricity  per  unit  of  surface 
of  contact.  Klecirolvsis  for  stricture  of  the  urethra  requires  the  ap- 
plication of  a  sufficient  quantity  of  negative  electricity  to  produce 
interstitial  softening  of  the  tissues  without  destruction  and  sloughing. 
The  proper  amount  is  about  '>  coulomb  per  square  centimeter  of  me- 
tallic contact  at  the  negative  electrode,  and  a  current  for  about  five 
minutes.  The  strength  of  the  current  will  vary  from  o  to  oO  ma.. 
depending  upon  the  size  of  the  electrode.  The  current  for  the  cure  of 
nevus  by  electrolysis  without  destruction  of  tissue  should  no1  exceed  about 
20  ma.  per  inch  of  length  of  positive  needle  in  electric  contact  with  the 
tissues  for  about  five  minutes.  A  greater  strength  will  produce  slough- 
ing. Twelve  to  twenty  galvanic  cells  in  series  will  supply  the  necessary 
current  for  treating  nevus,  but  as  they  may  very  quickly  run  down,  a 
storage-battery  or  an  arrangement  for  ut  ili/ing  t  he  direct  elect  ric-light  inu 
current  is  preferable. 

In  these  and  other  cases  the  current  density  is  almost  exactly  pro- 
portional to  the  voltage,  and  if  this  is  maintained  at  a  uniform  figure, 
it  d,>os  not  matter  so  much  whether  a  larger  or  a  smaller  surface  of  the 
electrode  is  in  contact  with  the  tissues.  If  large  galvanic  cells  are  used, 
the  voltage  will  b"  practically  constant,  and  will  depend  upon  the  num- 
ber of  cells  in  series,  each  cell  yielding  an  electromotive  force  of  about 
I  ,  •",;'',,  volts.  The  same  is  true  of  a  stora.ge-bai  tery,  but  each  cell  in  series 
vieid^  about  '_'  volts.  ("sing  either  twelve  large  ualvanic  cells  or  ten 
storage-cells  in  series,  or  arranging  the  table  for  utilizing  the  oloctric- 
hidil  current  in  such  a  way  as  to  yield  Is  volts,  a  suitable  current  would 
be  obtained  for  the  treatment  of  nevus  by  bipolar  galvanopuncture. 
while  a  considerably  greater  number  of  ceils  would  be  required  if  the 
monopolar  method  was  used,  and  an  indifferent  .-ponu'o  electrode  was 
applied  to  the  surface  of  the  skin.  In  the  treatment  of  superfluous  hair 
the  voltage  again  is  the  important  thing,  and  is  Usually  found  to  be 
(i  or  S  volts.  The  proper  voltage  is  secured  by  adjusting  the  appa- 
ratus in  the  treatment  of  the  first  hair-follicle,  and  i  hen  then1  is  no 
fur'  In1  r  regulation  of  the  current  while  different  hair-follicles  on  t  he  same 
par!  ot  the  face  are  under  treatment.  1  he  same  number  of  galvanic 
or  the  same  adjustment  <>t  the  volt  controller 
same  current  density,  though  the  varying 
icles  will  allow  of  different  areas  of  contact, 
and  the  milliamperemeter  will  indicate  a  different  current  strength. 
The  same  effect  is  produced  over  a  larger  or  a  smaller  surface  when  the 
voltage  is  constant,  and  the  milliampcrage  varies  in  consequence  ot 
variat  ions  in  t  he  area  of  coin  ad  . 

It    would  be  wrong  to  select  a  certain  number  of  milliamperes  and 
applv  i  hat  strength  io  every  hair-follicle,  varying  the  voltage  to  over- 


114  MEDICAL    ELECTRICITY    AND    KONTCiEN     RAYS 

conic  differences  in  re.-istance  due  to  inequalities  in  the  area  of  contact. 
The  same  number  of  milliamperes  passed  through  half  the  area  of  con- 
tact would  have  twice  the  current  density,  and  would  produce  a  much 

more  -evere  rttect . 

The  milliamperemeter  is  the  only  measuring  instrument   required, 

although  a  voltmeter  in  addition  would,  of  course,  give  direct  readings 
of  vultaire.  and  would,  therefore.  l>r  very  convenient.  The  regulation 
of  t  he  st  relict  li  of  the  current  is  effected  bv  a  cell-selector,  and  per- 
liap-  a  rheostat  and  volt -controller  in  the  case  of  galvanic  or  storage- 
cell-,  and  l-.y  a  volt-controller  and  rheostat  when  the  direct  elect ric- 
light  current  is  used.  The  milliamperemeter  shows  whether  all  the 
connection.-  are  right,  and  a  current  of  the  proper  direction  and  about 
the  proper  strength  is  flowing.  A  simple  voltmeter  may  be  improvised 
by  connect  im:  the  two  conducting  cords  with  a  16-candle-power  electric- 
light  bulb,  and  noting  the  number  of  milliati'peres  registered  by  the 
milliamperemeter.  AYe  know  that  2.10  ma.  require  a  voltage  of  110, 
and  -o  m  a  rough  way  1  he  number  of  volts  is  one-half  the  number  of 
milliamperes  which  the  batterv  will  drive  through  a  1  (i-candle-power 
incandescenl  lamp.  The  electrodes  are  not  connected  with  1  he  patient 
during  the  measurement.  Having  once  adjusted  the  apparatus  for  the 
proper  voltage,  it  is  easv  to  keep  it  there  or  to  reproduce  the  same  ad- 
justment. 

>'•  •(  nt/th  of  ( 'urn  nl  f«r  !)<//>  Klcctrolijxifi.-  The  diffusion  of  the  current 
from  a  small  area  of  con  1  act  with  1  he  elect  rode  is  so  great  that  no  current 
which  can  be  borne  by  the  skin  where  the  current  densitv  is  greatest 
will  produce  much  direct  effect  upon  a  deeply  seated  organ  where  the 
current  density  is  least.  A  reflex  effect  is  often  obtained,  and  is  fre- 
quently  verv  beneficial.  The  skin  over  a  deeply  seated  organ  is  often 
ivflt-xly  connected  with  it.  The  means  for  producing  a  direct  effect 
con-i-ts  m  ii-m  L:  extremely  large  electrode.-,  covering  the  whole  joint 
01  other  organ  to  be  treated.  Two  object-  are  accomplished:  the  lines 
"t  radiation  traverse  the  deeper  parts  in  abundance,  perhaps  even 
giving  a  greater  current  density  at  the  center  than  at  any  part  of  the 
-urface,  and  the  large  area  of  surface  contact  permit.-  of  the  passage 
fit  ven  heavy  currents  without  undue  current  densitv.  A  deep-seated 

.    in  thi-  wa  v  be  t  ra  versed  bv  current  -  a:-  -I  rong  as  t  hose  ordi- 
to  the  skin.      Here  again  1  he  proper  current  densitvat  the 
••'  •  in  coiit act   u  it  h  t  he  elect  rode  is  verv  import  a nt .  and  it  is  secured 
by  pr<  iper  regulai  ion  of  t  he  volt  age. 

I  he  current    density  is  u.-uallv  not    more  than    1   or  '2  milliamperes 

per   -quaff   inch   ol    surface  ot    the  -malle-t    electroije   for  a    continuous 

•at  ion  null  >-  |i   is  desired  to  produce  an  elect  rolvl  ic  effect .      1  f  t  his 

'heca-i  i          er  elect  rode  may  be  used  for  t  he  act  ive  elect  rode,  bill 

1 1  '     '    :  "'  n  :  '  elect  rode  .-ho u Id  be  large  enough  to  com  pi  v  with  t  his  rule. 

1  '•'  n'    electrode,  for  instance,  has  to  be  of  an  area  of  over   100 

<  •      '     '  '  •  •      \\hen  a  current  ot  '_'.~>O  ma.  i-  u.-ed  for  the  cataphoretic  or 

i  ic  de-t  rud  ion  ol  a  ca  ncer  ot  I  he  brea.-l  b\   mono  polar  gal  A  a  no- 

[.  Hid    I       . 

Electrolysis   for   Hypertrichosis.      A    fine   iridoplat  inum   needle  is 

•     |)ole  ol    t  he  1  ia  t  t  cry.        I  he  po.-it  ive  elect  n  ><  je 

pt.n-je  elect  {-,  ,je  the  insulated   handle  of  which  i-  held   by   the 

•  1 1  brea  ks  cont  act  h\   p  re-sing  the  pal  m  of  the  hand 

I  hi-  enable-  the  operator  to  have  both  hand-  free, 


IONIC    MEDICATION    BY    ELECTROLYSIS 


41", 


for  support  upon  the  patent's  face,  and  to  hold  the  handle  of  the  needle 
(Fig.  288).  Before  the  current  is  turned  on  the  needle  is  introduced 
into  a  hair-follicle,  eathoterizing  the  follicle  to  its  very  bottom.  Then 
the  volt-controller  and  the  rheostat  are  turned  on  so  as  to  allow  a  current 
of  from  '2  to  ~i  ma.  to  flow.  After  five  to  twenty  seconds  the  patient  is 
told  to  let  £0  of  the  sponge  gradually  and  the.  current  ceases  to  flow. 
Another  hair-follicle  not  too  near  the  first  is  then  catheterized,  and  the 


patient  told  gradually  to  press  her  hand  upon  The  sponge.  The  rheostat 
is  not  changed  for  each  hair,  but  when  passing  to  another  part  of  the 
face  which  may  be  more1  sensitive,  it  is  well  to  reduce  the  current  to  zero 
before  catheterizing  the  first  hair.  The  exact  length  of  time  that  the 
current  is  To  be  allowed  To  flow  is  not  To  be  measured  by  the  clock,  but 
by  the  effect.  A  little  foam  forms  around  the  needle  and  sometimes 
a  little  redness.  The  hair  should  come  away  without  any  traction  when 
seized  by  epilation  forceps.  It  requires  some  little  practice  and  judg- 
ment to  destroy  the  hair-follicles  without  undue  scarring.  Kven  an 
expert  will  have  To  count  on  20  per  cent,  of  the  hair  returning.  Scarring 
cannot  be  avoided  entirely,  but  it  is  very  much  less  if  successive  Treat- 
ments are  t  wo  days  apart  and  if  no  follicles  very  near  toget  her  are  treated 
at  the  same  seance.  Too  long  or  too  strong  an  application  will  cause 
bad  pitting,  almost  like  that  of  small-pox.  As  the  removal  of  a  com- 
plete beard  requires  the  destruction  of  10,000  to  20,000  hairs  of  large 
or  small  size,  and  as  it  is  impracticable  to  remove  more  than  twenty  to 
fifty  at  a  sitting,  the  tediousness  of  this  method  of  treatment  is  self- 
evident.  The  removal  of  a  few  large  coarse  hairs  scattered  among  the 
fine  lanugo  hairs  is  a  less  staggering  proportion,  and  so  is  the  removal 
of  a  few  coarse  hairs  situated  at  the  corners  of  the  mouth.  But  even 


41(5 


MEDICAL     KLK<  TKirlTY     AM)     l«  )\T< ,  K\     KAYS 


these  in;iy  involve  a  course  of  treatment  extending  over  a  year  or  two. 
After  all  the  hairs  whieli  it  is  desired  to  destroy  have  been  removed,  a 
certain  number  are  bound  to  return,  and  others  which  were  not  removed 
seem  to  become  coarse  and  require  removal.  The  patient  should  return 
after  two  or  three  month-,  and  everything  objectionable  should  be  re- 
moved. This  ha-  to  lie  done  over  and  over  aji'ain,  and  will  eventually 
succeed. 

If  a  >teel  needle  i-  used,  especial  care  must  be  taken  to  make  sure 
that  it  i-  connected  with  the  negative  electrode.  Positive  electrolysis 
with  a  -teel  needle  would  produce  indelible  staining  of  the  skin. 

Needle-  with  a  bulbous  instead  of  a  sharp-pointed  extremity  are 
recommended  by  Ilumphris  ("Electrotherapeutics  for  the  Practi- 
tioner ,  who  al-o  recommends  that  hairs  which  are  not  loosened  bv  a 
safe  cm-rent  -hould  be  forcibly  pulled  out.  They  will  certainly  return, 
but  then  may  be  destroyed.  Kubbin<r  some  black  substance  over  the 
surface  may  make  the  hair-follicles  easier  to  find. 

Electrolysis  in  Lymphangioma.  The  technic  is  the  same  as  for 
alii!  i'  MI  la  ca  vern<  i-a. 

Electrolysis  for  Angioma  Cavernosa.-  Monopolar  <ralvano- 
puncture  may  be  ])erformed  with  one  or  several  (as  in  Fi<:.  2SO)  irido- 
plaiinum  needles,  varnished  except  at  the  point,  and  connected  with 
U  i-  po-it  ive  pole,  while  the  nid  life  re  nt  electrode  is  made  of  a  flat  metallic 


ii      covered    with    felt    and   -urroundin.^  the   region   to  be   treated.      A 

'   oi  Ji  l  or  '_'.")  ina.  tor  about   five  minules  is  required. 
!  lie  motiopolar  method,   is  used  onlv  in  -pecial  cases,  where  there  is 

lo  111 1-vessels  or  nerves  from  the  bipolar  met  hod. 

I'ipolar  Lialvanopunct  lire  emplovs  insulated    needle-  connected   with 

i  he  source  of  coniinuoii-  current.      A  current  of  .'-5(1  or   |(i 

turned   on   and   allowed   to  run   lor  about    fi\'e  nnnute- 

lied    off.      Several    bipolar    punctures    mav    be    made 

1     •       '---ion.       The    positive    needle    retjllires    a    little    twisting    to 

n  i.'io1  •      •       iiil    the   negative  needle   i-   usually   perfectly   loose. 

vi-!     i ne!  hod    i-  emploved.  1  real  inent  s    -hould    I  ie    <j;iven    t  wice 

•  '   n    <  •>•  feels   1 1  l.e  a    hard,   solid    mass. 

•  o]    - "  all   Va-ciila)'  tumors   i-  accompllsheil  b\-  the  use  of  a 
'•  '•   -heilac.   c\cep|    al    ii  -   point .      This   is  to  be 
In  rat  ed  t  here,  cans  inn  coa  n  u  hit  ion   necrosis. 

•  I'li-d  n>l\  >i-   a    platinum   stem    I   or.")   nun.   in   diameter 

or   ll     Ilia  \'  be  made  ol    c  a  i  lion.      Tl  1 1-  d  isen^a.u'es  a  n 
.  c  iiii  eri/i  -   a  ml  d  i  - 1  ni  ert  -  the  in  erine  ca  vit  y. 
'      '  h'p  cat  hoi].'  i-  u-ed,  and  t  he  I'auteri/a!  ion  is  b\'  bases. 
Electrolvsis  for  Vascular  Nevi .      !  lal   nevi  uilh  visible  telanjiiecta- 
<•<:'.<  >\    b\    elect  rol\-i-,    and    if   \'er\    small.    I  he   irnlvano- 


IONIC    M  INDICATION     BY    ELECTROLYSIS 


417 


indifferent  spot.  A  current  of  ^  or  4  ina.  is  applied  for  about  five  min- 
utes. If  the  skin  turns  white  :iround  the  needle,  it  is  time  to  stop,  as 
t'uil  her  application  will  cause  destruction  of  tissue.  Larger  flat  nevi 
are  usually  treated  by  bipolar  galvanopune.turc.  The  positive  needle 
is  kept  in  one  position  at  the  middle  of  the  nevus,  and  the  negative 
needle  is  thrust  first  into  one  adenoid  vessel  and  then  into  another  until 
several  have  been  treated  at  the  same  session.  The  treatments  had 
better  be  given  once  a  week;  from  'JO  to  -10  ma.  are  required,  and  an 
application  of  about  five  minutes.  The  current  should  be  gradually 
turned  on  after  the  needles  are  in  position,  and  should  be  reduced  to 
zero  belo  re  t  liev  are  1  a  ken  out.  The  negative  needle  becomes  very  loose, 
and  care  must  be  taken  not  to  allow  it  to  slip  out  and  break  the  circuit. 
\\  ith  a  current  of  this  strength  a  disagreeable  shock  would  ensue. 

I. afire  nevi  are  best  treated  by  the  bipolar  method,  the  needles  being 
thrust    in    for    .',    inch  or  more    and    bemu;   parallel    with   each  other  and 


Fit:.  •-".)().  -Met hod  of 

witli  the  surface.  The  idea  is  to  cause  the  vascular  tumor  to  be  trav- 
ersed hv  a  current  of  uniform  strength  at  all  parts.  Too  marked  an 
effect  upon  t  he  t  issues  wi m Id  cause  sloughing,  and  t  his  is  not  at  all  neces- 
sary  in  order  to  effect  a  cure.  The  appearance  of  lividity  or  blackening 
of  the  tissues  indicates  too  long  or  too  severe  an  application. 

Port-wine  Stains.  The  electrolytic  treatment  of  these  birth- 
marks is  accomplished  by  the  bipolar  method.  Tin1  positive1  needle-  is 
t  hrust  into  a  certain  part  of  the  port-wine  stain  rat  her  near  t  he  periphery. 
and  a  series  of  punctures  are  made  around  n  with  the  negative  needle. 

Several  such  positive-  punctures  surrounded  by  a  circle1  e>f  negative 
punctures  are  required,  The-se-  should  be  tar  enoujjh  apart  to  piwent 
confluence  of  the  superficial  sloughs.  The  current  should  be  of  a 
strength  of  from  JO  to  10  ma.,  and  the  usual  precautions  are-  taken  to 
prevent  shock.  The  results  are  not  so  uniformly  satisfactory  in  the 
treat  me-nt  of  port-wine  stains  as  in  the-  treatment  of  the-  smaller  ne-vi. 


418  MEDICAL    ELECTRICITY    AND    KONTGEN    RAYS 

Tin  Liqniil-dir  Triatrnint  of  I'/irt-irinc  Xtainx.  —  This  has  been  used 
successfully  hv  1'usev.  Ife  uses  the  sno\v  or  frost  formed  by  exposing 
liquid  aii'  in  an  open  vessel.  This  intensely  cold,  white,  powdery  mass  is 
spread  light  Iv  over  the  port-wine  stain.  As  it  gradually  disappears  in  the 
form  of  ordinary  air.  intense  but  superficial  free/ing  of  the  tissues  takes 
place.  This  is  followed  by  a  superficial  slough,  and  in  cases  which  he  has 
reported  the  improvement  in  appearance  has  been  very  marked  indeed. 
Carbonic  acid  snow  is  used  in  the  same  way. 

Tin  Triiiti/n  ill  <>f  I'nft'iri/if  N/ar/f.s  hi/  X-rin/.  —  This  means  of  treat- 
ment i>  considered  on  p.  1  1TS. 

Electrolysis  for  Hairy  and  Pigmented  Nevi.  —  One  method  of 
treatment  is  by  electrolysis  of  each  of  the  different  hair-follicles,  using 
the  same  technic  as  for  hypert  richosis,  and  this  usually  causes  a  suffi- 
cient disappearance  of  the  entire  nevus.  If  an  additional  treatment  is 
required,  the  base  of  the  nevus  may  be  transfixed  by  two  or  more 
negative  needles  parallel  with  each  other  and  with  the  surface,  while 
the  positive  electrode  is  held  in  the  hand.  The  current  sufficient  for 
the  first  part  of  the  treatment  for  the  destruction  of  hair-follicles  should 
be  from  '_'  to  .")  ma.,  while  for  the  second  part  of  the  treatment  a  current 
of  from  20  to  '••>()  ma.  is  required. 

The  ./--ray  may  be  found  preferable  when  the  hairy  nevus  is  very 
large  and  all  the  hairs  are  very  coarse  and  strong. 

Eli  <•//•(>/  ;/*/N  fur  ll'a/Y.s'.  —  Negative  monopolar  galvanopuncture  or 
bipolar  galvanopuncture  with  a  current  of  20  to  '•)()  ma.  destroys  these 
irrowt  hs. 

I  reatment  by  the  .r-ray  or  by  the  application  of  radium  is  somewhat 
to  be  preferred,  and  high-frequency  sparks  are  wonderfully  effective. 

Electrolysis  in  Acne  and  Acne  Rosacea.  --Large  comedones  may 
be  treated  by  the  same  technic  that  is  used  for  hypert  richosis.  llyper- 
;  rophy  of  the  nose  requires  electrolytic  treatment  of  the  different  folli- 
••les.  and  after  the  subsidence  of  inflammatory  reaction,  may  be  treated 
by  unipolar  negative  galvanopuncture.  The  current  for  the  first  part 
•it  the  treatment  should  be  of  a  strength  of  about  o  ma.,  while  for  t  he 
-econd  part  about  20  ma.  are  required.  The  results  obtained  are  very 
Liood  indeed,  but  .  of  course,  1  he  met  hod  must  be  applied  wit  h  great  care 
to  prevent  -earring. 

By  another  method,  the  electrolytic  needle  is  applied  for  acne  with 
a  current  of  2  to  1  ma.  for  three  to  five  minutes,  ignoring  the  anemia, 
which  occurs  in  a  few  seconds.1 

Angiokeratosis  and  tattoo-marks  are  treated  in  the  same  way.  Elec- 
tr  ily.-i>  i-  "i  doubtful  utility  in  lupus  eryl  hematosus. 

Sycosis  i-  sometimes  treated  by  an  electrode  wet  with  2  per  cent. 
solution  ot  corrosive  sublimate,  applying  a  rhythmically  reversed  cur- 
rent tor  fitly  minutes,  or  better,  several  shorter  treatments.  This  is 


culo-i-    i-    -Micressfully    treated    l>y   cataphoresi 

rm-ive  -ublimate  or  of  /.me  sulphate. 
oiiier  lia.-  tri<-d  cataphoresis  with  ergot  in  with  encouraging 

acne  pi-area  of  the  no-e  and  cheeks. 
trliinir  of  lichen  ruber  is  relieved  bv  ouinin  catanhore-is. 


IONIC    MEDICATION    BY    ELECTROLYSIS  419 

Phagedenic  chancre  may  be  treated  by  corrosive  sublimate  cata- 
phoresis. 

For  cocain  cataphoresis  a  o  or  10  per  cent,  solution  is  applied  for 
ten  or  fifteen  minutes  and  the  anesthesia  lasts  thirty  minutes. 

Dermatitis  papillaris  capillitii  may  be  treated  by  the  negative  gal- 
vanic needle,  but  the  a>ray  lias  given  much  better  results  in  some  cases 
under  the  author's  observation. 

Electrolysis  for  Sebaceous  Cysts. —  If  excision  cannot  be  per- 
formed, the  cyst  may  be  destroyed  bv  galvanopuncture.  The  positive 
electrode  is  so  arranged  as  to  surround  the  cyst  at  a  distance  of  \ 
inch  from  it.  The  uninsulated  needle  connected  with  the  negative  pole 
of  the  battery  is  thrust  into  the  middle  of  the  cyst,  and  a  current  of  from 
S  to  10  ma.  is  applied  for  two  or  three  minutes.  The  needle  is  then 
removed,  and  occlusive  dressings  are  applied:  two  or  three  days  later 
an  insulated  needle  is  thrust  through  the  slough,  so  as  just  to  reach  the 
wall  of  the  cyst,  and  a  negative  current  of  about  10  ma.  is  again  applied. 
Three  days  later  it  may  be  found  practicable  to  express  the  entire  soft- 
ened mass  through  the  little  opening  which  is  left  by  the  removal  of  the 
cutaneous  slough. 

Electrolysis  for  Keloid. — Negative  monopolar  galvanopuncture 
current  of  about  5  or  6  ma.  may  be  employed. 

Electrolysis  for  Warts. —  I'edunculated  warts  are  treated  by 
thrusting  the  negative1  needle  through  the  wart  at  a  distance  from  the 
skin.  A  current  of  2  to  4  ma.  is  allowed  to  flow  for  perhaps  two  to  five 
minutes,  until  the  wart  has  seemed  to  become  blanched  and  looks  like 
an  herpetic  bulla.  This  is  rather  painful,  and  it  is  better  to  use  ethyl 
chlorid  as  an  anesthetic.  A  steel  needle  can  be  used  perfectly  well. 
The  same  method  may  be  used  even  if  the  wart  is  sessile.  The  author's 
patients  greatly  prefer  the  high-frequency  spark. 

Electrolysis  for  Nasal  Polypi. — Negative  monopolar  or  bipolar 
electrolysis  may  be  applied  with  a  current  of  about  20  ma. 

Electrolysis  for  Ozena. — This  must  be  done  under  local  anes- 
thesia. A  pure  copper  needle  connected  with  positive  pole  is  thrust 
into  the  middle  turbinated  bone,  and  a  steel  needle  connected  with  the 
negative  pole  is  thrust  into  the  inferior  turbinated  bone.  The  needles 
should  be  about  JT  inch  in  diameter,  and  should  penetrate  about  1  inch 
of  tissue.  A  current  of  from  10  to  15  ma.  is  gradually  turned  on,  and 
allowed  to  flow  for  about  ten  minutes.  Ir  is  then  gradually  turned 
off  and  reversed  for  a  short  time  in  order  to  loosen  the  positive  needle. 

Electrolysis  for  Nasal  Deviations  and  Spurs.  --Bipolar  galvano- 
puncture of  the  convex  surface  with  a  current  of  about  20  ma.  for  ten 
minutes  is  very  effect  ive. 

Electrolysis  for  Dilated  Blood-vessels  in  the  Skin  of  the  Nose.— 
This  condition  requires  manv  separate1  gal  van<  ipunct  ures  of  1  he  different 
blood-vessels  at  a  considerable  number  of  sessions.  The  treatment  of  a 
case  may  extend  over  as  much  as  a  year.  Strikingly  good  results  are 
often  obt  ained. 

Electrolysis  in  Vegetative  Conjunctivitis  or  Spring  Catarrh.— 
Cocain  and  adrenalin  are1  necessary  to  secure  complete1  local  anesthesia, 
and  it'  the'  patie-nt  is  restle>ss,  perhaps  a  general  anesthetic  will  be1  re- 
quired. The  indifferent  electrode  (positive1,  usually,  but  it  makes  little 
difference)  is  applied  to  the-  foreliead  or  cheek.  The  eithe-r  electrode'  is 
a  platinum  needle-  which  is  thrust  into  the  different  vegetations  as  close- 


420  MF.DH'AL    KLKCTKiriTY    AND    K<  )NTGEN    KAYS 

to  their  base  as  possible,  and  parallel  with  the  surface  of  the  conjunctiva. 
I'o—iblv  several  mav  be  t  rail-fixed  at  the  same  time.  Flat  vegetations 
are  treated  hv  .-cariticat  :<  n\  \\ith  i  he  same  needle  held  perpendicular  to 
the  surface.  A  current  of  from  '_'  lo  ^  ma.  is  used  -not  more  than  ^  ma. 
if  cocain  alone  is  used.  Stronger  currents  cause  pain  and  lacrimation. 

1'aii-ier  has  u-ed  'his  technic  successfully. 

Electrolysis  in  Macroglossia.  When  this  is  due  to  tin'  presence  of 
lymphat  ic  cysts  in  t  he  >ul>st  ance  of  the  tongue,  repealed  bipolar  elect  ro- 
lysis  under  ;in  anesthetic  will  effect  a  cure.  The  technic  is  the  same  as 
for  aii^ioma  cavenn  >sa  (p.  4  Hi). 

Electrolysis  in  diseases  of  the  Vulva. — Vegetations  may  be 
treated  bv  u'alvaiiopunct  lire,  bipolar  or  monopolar,  and  with  a  current 
o !  a  b  o  u  I  .")  m :  i . 

( 'hronic  folliculit  is  vulva-  may  be  t  reated  by  positive  «;alvanopuncture 
with  imicii  the  same  technic  that  is  used  for  hypertriehosis  (p.  414\  A 
current  of  '_'  to  ~>  ma.  is  ap]>lied  for  five  to  twentv  seconds. 

Electrolysis  in  Urethral  Stricture,  hurt's  nnttmil  of  linear  dctro- 
'•t*i.-  by  means  of  a  ne^at  ive  electrode  shaped  very  much  like  a  uret  hro- 
tome.  and  ad  inu  somewhat  like  the  blade  of  a  jralvanocautery.  is  generally 
regarded  as  dangerous  and  undesirable.  A  current  of  from  lo  to  ">()  ma. 
i-  used.  The  indifferent  electrode  is  placed  upon  the  abdomen. 

A  '  it'nni  n'*  i  m  tin  a  I  nf  a  /•'-,  /In  r  t  Ii  rfrn!  '/.-•!  *  is  safe  and  effect  ive.  and  is  one 
ol  the  n  lei  hod-  o]  choice.  The  ne^at  ive  elect  rode  is  t  lie  act  ive  one.  and 
coiisi-t-  di'  one  of  Xewman'-  olivary  urethra!  bougies,  the  next  size 
larger  i  lian  t  he  smallest  st  rid  ure.  \\'hile  t  he  elect  rode  is  pressed  lightly 
airain-i  i  he  strict  un1,  a  dirreiit  ol  trom  '•>  to  III  ma.  is  gradually  turned 
on  just  enough  to  cause  a  sensa!  ion  of  \varmth  aiul  prickling.  About 
twenty  minutes  application  mav  be  required,  and  then  this  strictur<' 
be  found  passable  by  a  larger  olivary  <'ledrode  \\hich  may  be  Used 
to  t  re;ii  allot  h<'l'  larger  strict  Ul'<-.  The  iiulif'l'erent  electrode  is  held  on  t  he 
abdomen.  Ton  UTeat  an  effect  is  not  soliuht  at  each  session  perhaps 
rease  ol  onl\  one  or  t  wo  numbers  ol  i  he  Fr<-nch  scale  in  tlu-  dia m- 
ei rr  of  each  si  rict  ui'e.  The  t  reat  nients  are  u'lven  at  intervals  of  a  \v<-<-k 
ni  '  -.  I  i. .;: '  a  MI  in  bv  ordinary  sound-  is  u-ei]  m  coimedion  with 

eel  |-i  ii  vi  K-   !  rea  I  HK'IIt. 

'  -    ,1  n  .in    is    tli<-    name   niven  to  a  HH'thod  in  which  me- 

'  it  ion    i-  i  he  principal    fact  or.  t  hoimh  t  he  dilat  inii'  sound   also 
I    ol    tieuative  eledricity.      The   dilatation    may   be   >-lmr. 
:  •  t  roii        '  i  lira  1  sound  \\  hich  is  la  ri;e  enough  to  pass  I  hrouuh  t  he 

lie  slretchini;.  and  allouinu  a  current  of  from   ~)  to  .'!() 
.   to   lif  i       loi    '  vi     in  in  ul  i1.-  or  1<  •-.-.      The  t  real  n  lent  s  are  L:I  veil  once  a 

.    •  '       .         I   IH      lln  i    t'fi   I'enl    e|ed  rode    1-  ;i   la  I'll  e  one  placed   over  |  he  abdomen. 

\      ii  .'    •    '••    '      •     portion  oi   the  metallic  sound   is  insulated  bv  varni-h. 

'    •  •  current  and  the  length  ol  lime  for  which  it  is  applied 

i '•  n  laiion  In  ihe  amount   ol    surface  provided  for  t  he 

•    contact.        I  in'    proper    i|Ualitit\     ot    electricitv    for    each    sijiiare 

cell*  r    •  ' '  • •:  ric    ci  inl  ad    i~   about     ,'',,    cimlomb.  or   t  he  amount    of 

po"'cil  i.\   ;i  current  «\  '_'  ma.  in  fi\'e  niinuti-s.      ('alculat- 
i-'-d  i    el     |  sinlace  in  contact  \\  il  h  t  h<'  uret  hral  mucous 

l:;e",b      '  -  |)l\'ini;    the    number   o|     sijllare    centimeters    bv   '_'. 

•  :  ol  iiiilliainperes  >*\  current   which  -hoiild  be  applied 


IONIC    MEDICATION     BY    ELECTROLYSIS  421 

for  five  minutes.  This  will  be  from  5  to  '••>()  ma.,  depending  upon  the 
si/e  of  the  sound  ;ind  the  length  exposed. 

The  rapid  ///clhod  of  electrolytic  dilatation  uses  the  same  strength 
of  current,  hut  a  sound  ahout  five  numbers  (French)  larger  than  the 
si/e  of  the  stricture.  Firm  pressure  is  applied,  and  the  sound  passes 
through  the  stricture  in  a  few  minutes.  Two  or  three  different  sixes  are 
used  at  each  session,  and  the  treatments  are  given  once  a  week. 

Electrolysis  for  Esophageal  Stricture.  /'W/'.s  im-tliod  of  linear 
electrolysis  is  dangerous  because  of  risk  of  injury  to  neighboring  organs. 

Circular  <'lrctrolt/*it<  is  perfectly  safe,  and  is  performed  witli  an  olivary 
metallic  electrode  adjusted  upon  a  flexible  stem,  which  extends  '2  or 
)•>  inches  beyond  the  elect  rode,  and  which  contains  an  insulated  wire. 
The  whole  forms  an  olivary  esophagcal  bougie.  This  is  connected  with 
the  negative  pole,  while  the  indifferent  positive  electrode  may  be  held 
in  the  patient's  hand.  A  current  of  4  or  5  ma.  should  be  gradually 
turned  on  while  the  olivary  bougie  is  pressed  gently  against  the  face  of 
the  stricture,  and  in  a  few  minutes  the  olivary  bougie,  which  should  be 
the  smallest  one  which  would  not  pass  the  stricture,  now  goes  through 
readily.  Sometimes  the  next  higher  number  also  may  be  made  to 
penetrate  freely  at  the  same  seance.  Treatments  should  be  given  about 
once  a  week,  and  the  method  is  not  applicable  to  obstruction  from 
pressure,  as  by  tumors  and  aneurysms. 

Electrolysis  in  Stricture  of  the  Lacrimal  Duct. — A  Bowman's 
sound,  insulated  by  varnish  except  at  its  extremity,  is  connected  with  the 
negative  pole,  while  a  positive  electrode  is  held  in  the  hand.  A  current 
of  about  o  to  4  ma.  is  applied  for  three  minutes  once  a  week. 


EXAMPLES  OF  GALVANIC,  FARADIC,  AND   SINUSOIDAL 
ELECTROTHERAPY 


THERAPEUTIC  EFFECTS  OF  OALVANIC.  FARADIC,  AND  SINUSOIDAL 

CURRENTS.' 

I  |  ( 'athodal  closure. 

Alternating    galvanic    currents    with    or 
(ialvanism.  -j       without  condensers. 

Prolonged  cathodal  application   (catelee- 
I       trotonusj. 
f  Successive     discharges     of     the     induced 

break  current. 

Faradi.-m.  '  Successive  discharges  of  the  primary  cur- 
galvano-  \  rent  at  the  moment  of  opening  of  the 
faradism.  !  circuit. 

j  Sinusoidal  current . 

Short   waves  from  a  small  condenser, 
f  Alternating  galvanic  currents  with  or  without  conden- 
sers. 

(  'athodal  closure. 
|   Faradism,   (-specially  with  a  short   secondary  winding 

rhythmic  or  i.-olated  waves,  or  sinusoidal). 
i  (  ralvanofaradi.-m. 

I  Same  as  for  excitomotor ,  e.-pecially  faradism,  with  a  long 
i       .-econdary  winding  and  rapid  interruption. 
i  (ialvani-m.  i  Applied   to  glands  which  are  sufficiently 
i  Faradi-m.     )       acce.-.-ible  to  receive  a  strong  current. 
-  |  Faradi.-m  with  lonu  secondary  winding  and  applied  by 
•;.    '    .  .   nail  '•nniliitliiit/  ir-  '       metal  brush. 

nr Jlnxinu  I  (lalvanofaradism  applied  by  metal  brush. 

Faradi.-m  with  -hort  .-i-condary  winding. 
A  -ee<>ndar\   effect  from  va-oconstrict  ive  applications. 
Faradi-rn  with  lonu  .-econdary  winding. 
Triple    phar-e   or   .-inu.-oidal   currents   in    hydro-electric 

bath. 

I  ie\'ul.-i\-e  and  va.-odilat  ive  a  ppl  i  cat  ions. 
Heat  applied  in  various  ways.      Compre.-sed  air-douche 
'lull  x.    I         heated    bv   electricity. 
I  (  ialvani-m. 
I    '  ialvalil-m   \\lth   iDtn/ation  l<  itit  •  iphoresis. 

i   1 1  \ 'drnfaradic     or      h\drosinus- 
i        oidal  bath-. 

Hhythlnic  general   faradl/.at  ic  >n. 

(  icneral  galvanix.atii.il.         !  I  vdniL'alvatiic  bath.-.  ) 
•  Cerebral. 


Mod  .  \!   !.-l,:id','-   table,    Le-   App 


GALVANIC,    FARADIC,    AND    SINUSOIDAL    ELECTROTHERAPY          42.3 

Stimulating      the       natural  ( 

means  of  defense  of  the  I  Hydrogalvanofaradic  and  hydrosinusoidal  baths. 

organism ( 

f  Galvanism  (prolonged  anodal  application). 
Galvanism  (Leduc  currents). 
Hydrogalvanic  baths  (prolonged). 
Hydrogalvanic  enemata,  etc. 


Xcdatirc  or  calmative,  inhihi- 


Undulatory  faradization  with  wet  electrodes. 


,      .  ..      Monodic  faradization  (Stas). 

five,    analgesic,    or    anti-     sinusoidal  faradization. 

'  1  Secondary  effect  of  revulsive  applications. 
Variations  of  an  electromagnetic  field. 
Douche  of  air  heated  by  electricity. 
|  Quinin. 


Radium,  etc. 

f  Hydrosinusoidal  baths  in  insomnia  due  to  circulatory 
•j       disorders. 

(  Leduc  currents  (experimentally). 
r        ,  j  Anodal  galvanism  (by  electrolysis). 

I  Heat  produced  by  electric  means. 
f  Prolonged  anodal  galvanism. 

1    ,•      /•  j  Iontophoresis  (copper,  zinc,  silver,  etc.)  by  electrodes, 

wet  with  a  solution  of  salts  of  these  metals  or  by  elec- 
{      trodes  of  the  metals  themselves. 
Destructive  of  abnormal  (is-  (  Electrochemical  or  electrolytic. 

sues..  •  1  T-i          ti         •      '  Galvanocauterv.          Douche    of    air 

1  Electrothermic.  -       h(?atp(l  Vfiry  ^ot  hy  eloctrioitv 


Not  included  in  this  list,  but  considered  in  other  sections  of  the  book, 
are  the  stimulating  effects  of  the  static  electricity,  high-frequency  cur- 
rents, electric  light,  and  electric  heat;  also  the  excitomotor  effects  of  static 
disruptive  applications  and  static  wave  currents  and  undulatory  dis- 
charges of  high-frequency  currents;  also  the  extitosensitive  effect  of  high- 
frequency  sparks,  which  are  preferable  to  static  sparks  for  this  pur- 
pose, and  the  diaphoretic  effect  of  electric-light  baths  and  dark  heat 
baths  (Dowsing  method);  the  revulsive  effects,  etc.,  of  static  sparks, 
high-frequency  currents,  electric  light,  electric  heat,  diathermy  by  high- 
frequency  currents;  the  vasoconstrictive  effect  of  high-frequency  reso- 
nator sparks  and  energetic  efrluviation  by  high-frequency  or  static 
electricity;  the  vasodilative  and  hypotensive  effect  of  high-frequency  cur- 
rents, and  the  electric  arc  bath  and  other  luminous  heat  baths:  the 
the  resoh'/ny,  etc.,  effect  of  static  wave  currents,  high-frequency  cur- 
rents from  vacuum  electrodes,  electric  heat  and  light  locally  and  as  a 
bath,  diathermy  by  high-frequency  currents,  Hontgen  rays;  the  sclero- 
li/tic  effect  of  electric  light  and  diathermy  by  high-frequency  currents; 
the  excito  nutritive,  etc.,  effect  of  convective  and  conductive  static  ap- 
plications. autocondensation  and  autoconduction  by  high-frequency 
currents,  Tcsla  undulatory  high-frequency  currents,  rhythmic  effluve  with 
Tesla-Thomson  high-frequency  apparatus,  general  electric-light  bath, 
inhalations  of  ionized  air;  also  stimulating  the  means  of  defense  by  high- 
frequency  autocondensation  and  autoconduction.  conductive  and  con- 
vective <tatic  applications,  electric-liu'ht  bath,  ultraviolet  rays,  diath- 
ermy: the  sedative,  etc..  effects  from  conductive  applications  of  static 
electricity,  high-frequency  effluve,  Hontgen  rays,  blue  electric  light, 
ultraviolet  rays,  electric  heat,  dark  or  light,  diathermy:  also  hypnotic 


121  MEDICAL    ELECTRICITY    AND    HONTGEN    RAYS 

i  jji  C/N  from  static  bat  1  is:  al-o  coat/ it  lout  effects  from  fulgurution;  also  anti- 
.-•(  /tin-  effects  fn un  liiiht.  ultraviolet  rays,  high-frequency  eflluve,  static 
bree/e:  /it .  v/n/r//Y<  effect-  from  elect  rot  henny  by  the  de  Forest  cold 
cautery;  diathermy  and  elect  rocoagulat  ion,  cauteri/mg  arc  of  the 
Te-la-Thom-oii  high-frequency  apparatus,  high-frequency  resonator 
-park  •  fultrurat  ion  .  and  the  <l<  *trnct/r<  effect  of  concentrated  light, 
1 1  out  gen  ray-:  al-o  t  he  n/otlijictilion  of  tin  hit  H  id  by  Rout  gen  rays,  useful  in 
leukemia,  nseudoleukemia,  etc. 


(, FM.i;  \\.  INDICATIONS  FOR  Till-;  KFFKCTS  OF  CALVAN1C,  FARADIC, 
\ND  SIN  I  SOI  DAL  (TRRKNTS  (Mnclmtlu'*  'l'«l>l.  I. 

j  ( 'uralile  central  paralyses. 
-,  Curable  peripheral  paralyse.-  and  pare-es. 
(  Atony  or  myasthenia  of  stri|>ed  and  un-tnped  muscles, 
('uralile    central    paralyse. ;    of    sensation    and    hyperes- 
•      nnil     <  .rcilu-  thesia  and  anesthesia. 

]  ('uralile  peripheral   paralyses  of  sen-ation   and   hyper- 
csthesia  and  anesthesia. 

•  •••"•,     .  .  Lacteal,   seminal,  etc.,   hyposecretion. 

I'd  • .  .  Kr\  thema.  pruritus,  etc. 

Vu.tinliliitirt K.-pecially  in  cases  of  hiiih  arterial  tension. 

I   Inflammations  in  the  static  of  resolution. 
tit  /  'ilxn'i ,  tit  rti'iittr*.  t'lmiiti  r-  '         i    •  •  -   11      i  i  -vi 

,  Arthritis,   especially   blennorrhaiiic,   metntis.        Muco- 

illi<l     riiniiti  I'll uj'-  ,s   .  i-    •  •    •          i  i    i  -i- 

riiernhrarious  colitis,  myelitis,  neuritis,  phlebitis,  etc. 

(  Rheumatism,  edema,  hydrarthro-is,  sprains. 
.  I-'ibririoii-  andiylo-i-,  pleuritic  adhesions,  etc. 
liradytrophia,  especially  arthritisrn,  -ho\\in»-    itself    as 

tiollt.    diabetes,    obesity,    etc. 

Neurasthenia  with  depressed  nutrition. 
•'  Convalescence  from  prolonged   illne-s.  e-jiccially  if  m- 

t('Ct  H'C. 

\anco-e  ulcers,  muscular  atrojihies.  trophoneuroses  of 

the  skin. 

(  Sydenham's  ch<  >rea. 
j  Hysteria  of  hyperexcitable  type. 
f  Neuralgia-  produced  by  curable  lesions. 
i  Neuralgia.-  oi'  ;,  toxic  infection  of  dy-cra-ic  oriirm. 
I lypersthenic  dy-pep-ia.  jia.-traljiia  with  hyperchlorhy- 


-  .  \  1 1  <>  i  1 1 1 1 1  a . 

I  Nevus. 

j  Tuberculi  i-j-  ( if  a   -Ii  >w  type. 

•'  Art  hrit  ic  ti  ixemia. 

I  1  nfeci  ion  and  ailti  i-inlt  >xicat  it  in. 

i  \ 'arii  in-  dermati  i-e-. 

i  \Vnuiids.   illcerat  j,  in-.,  etc. 

)  Trail  mat  ic   LTaimrene. 

Diabetic   L'aliurene 

I  LupU-.   etc. 

(    \dcniti- 

<  ilandular  t  iitin  ir-. 
I    I  ibromata  and  other  neojil 


Gonorrhea!  Rheumatism  and  Galvanic  Currents.      IVillinkin1  cured  a 
'•  n|    Klfiiiitii    '  arthiitis  of  the  \\TI-I   1>\'  hea\'\'  galvanic  currents. 

''  '••!-'•  \\.-i-  at  a  tno-1  acute  -taire,  the  \vri-t   iiie;i-ui'iiiL;  '2  inehe-  more 
I '.  .  ':      i     d'         -ocii'ti'-.  i  rain       e  i  •  i  -  ratin  .  .linn     I'.io.'i 


(JALVAMC,     FAHADIC,    AND    SINUSOIDAL    KLK(  TROTH  KKAI'Y  425 

in  circumference  than  the  other,  and  being  stiff  and  painful.  It  had 
begun  to  be  painful  five  days  previously.  Kach  elect  rode  consisted  of  a 
sheet  of  metal  7  by  10  inches  in  size,  with  a  very  thick  layer  of  wet  ab- 
sorbent cotton.  The  negative  electrode  covered  the  hand,  wrist,  and 
three-quarters  of  the  forearm  while  the  patient  was  seated  upon  the 
positive  electrode.  A  current  of  1'JO  ma.  was  applied  for  fifteen  min- 
utes each  day,  and  was  followed  by  immediate  relief  and  a  permanent 
cure  in  four  or  five  days. 

Delherm's  method  is  to  apply  a  continuous  current  of  GO  to  100  ma. 
for  from  thirty  to  sixty  minutes.  Large  electrodes  are  placed  at  the  two 
sides  of  the  joint.  It  should  be  commenced  at  the  beginning  in  the 
acute  inflammatory  febrile  stage.  There  is  relief  from  the  very  start. 
The  pain,  fever,  and  swelling  disappear.  Ankylosis  is  prevented  when 
the  treatment  is  begun  at  this  early  stage.  At  later  stages  the  treat- 
ment is  not  quite  so  effective,  but  still  does  a  great  deal  of  good. 

Heavy  Galvanic  Currents  in  Acute  Gout  and  Rheumatism. — A  cur- 
rent of  110  ma.  may  be  applied  for  twenty  minutes  from  a  large  posi- 
tive electrode  on  the  dorsum  and  a  large  negative  electrode  on  the  sole 
of  the  foot.  A  five-minute  application  of  sinusoidal  currents  of  a 
strength  of  15  ma.  is  a  desirable  termination  to  the  treatment.  Billin- 
kin1  reports  the  curt1  of  such  an  attack  in  two  treatments. 

A  current  of  50  to  80  ma.  from  two  large  electrodes  applied  to  the 
knee  in  a  case  of  acute  rheumatism  of  that  joint  effected  a  cure  in  three 
or  four  days. 

Electromechanotherapy  (p.  483)  is  of  value  in  some  cases  of  chronic 
articular  rheumatism,  because  of  the  increased  respiratory  exchanges 
produced  by  electric  exercise. '- 

Faradic  Currents  in  Hydrarthrosis  of  the  Knee.  — /J/'/m/'.s 
tnctlmd  is  to  stimulate  all  the  different  muscles  of  the  thigh  in  succession, 
keeping  one  electrode  at  the  upper  and  outer  part  of  the  thigh,  and 
applying  the  other  to  the  different  motor  points  in  succession  for  twenty 
seconds.  This  part  of  the  treatment  is  very  painful.  The  electrodes 
are  then  applied  at  either  side  of  the  patella  for  five  minutes.  The 
claim  is  made  that  a  cure  is  effected  in  a  few  days  without  immobiliza- 
tion, and  that  there  is  immediate  benefit.  The  objection  is  the  pain. 

Danger  of  Galvanic  Currents  in  Tubercular  Arthritis. — The 
current  is  to  be  cautiously  applied  in  t  ubercular  art hrit  is  and  in  a  patient 
who  has  tuberculosis  of  any  other  organ. 

Faradic  and  Galvanic  Currents  for  Hydrarthrosis. — Strong 
galvanic  currents  applied  from  large  electrodes  covering  both  sides  of 
the  joint  have  been  considered  the  method  of  choice,  but  the  author  has 
used  the  milder  high-frequency  currents  with  success  (p.  583). 

A  faradic  coil  with  fine  wire  and  rapid  interruptions,  and  as  strong 
a  current  as  can  be  tolerated,  may  be  used  in  the  treatment  of  hydrar- 
throsis.  This,  however,  is  a  painful  method. 

Vibration  is  useful  for  stiffness  of  the  fingers  after  injuries  such  as 
('olles'  fracture  and  dislocation  of  the  shoulder.3 

Rheumatoid  Arthritis.-    Faradization  of  the  muscles  about   a    oint 


42«) 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


and  :rnjiliH' 
Disinj'tctanl .  . 


ELECTROTHERAPEITIC       INDICATIONS      IN      SKIN      DISEASES. 

(Virgilio  Machado's  Classification.) 

Stimulating   .  .    Falling  of  the  hair,  alopecia,  atonic  ulcers,  sclcroderma. 

s-    ,     -  i  Pruriginous    dermatoses    (lichen,    prurigo.    eczema,    herpes 

(       zoster. 
\'a*oci>n*trictin Krythemata. 

ting  tht  ahanr^ttnn  nf  •    Kdemata  following  contusions. 
txudah*  '   ( 

i  Dermatoses  due  to  general  nutritive  disturbance. 
t  Localized  trophoneurotic  dermatoses. 
.  .Septic  wounds,  ulcers. 

|  Elephantiasis,    certain    varieties    of    eczema,    mr-vi, 
El>  rlrnl ijttc.  .  .          angiomata.  hypertrichosis.  alopecia  areata,  sclero- 
(      derma,  acne. 

JGalvanocautery.  (Lupus,  certain  varieties  of 

High-frequency  sparks  j      epitheliomata,    phagede- 
Static  s{>arks.  ]       nic    ulcers,   Rontgen-ray 

ulcers.1 
[  Compressed   air  heated  by  electricity.     Ulcers. 

(  Lupus,  especially  vulearis  or  tubercular,  certain 
hi'  ctroitiiototiK  rn  in/.-  •  i    i-  '  c   •   i    i  •     j- 

I      epitheliomata;  many  superficial  skin  diseases. 

(  Epitheliomata,  especially  superficial,  sarcoma, 
rodent    ulcer,   lupus.-   elephantiasis,   mycosis 
fungoides.     Kerion  c^l-i,  acne  rosacea,  acne 
vulgaris.  acne  keloid.  sycosis  frambesiformis. 
Tinea  favosa.  onychomycosis  favosa,  tricho- 
phytina,  lichen  simplex,    lichen    ruber.    and 
acuminatus.     SVCOMS.     furunculosis    nuchae. 
microsporia.  hypertricliosis.  chronic  eczema. 
seborrheic  eczema,  alopecia  areata,  nevus  vas- 
culans  planu.s.     Ichthyosis,  pemphigus  vege- 
tans.  psoriasis,  neurodermatoses,  scleroderma. 
|>ruritus.    herpes    zoster,    herpes    tonsurans, 
|)rurigo.  trichorrhexis  nodosa,  scrofuloderma, 
hyperidrosis.    verruca,    verruca    necrogenica 
cutaneous  tuberculosis  i. 
I  '!<•*  rtititinx  (xtiliri/lic  nr  zini-  iontofthorcaix}. 
\  Secondary  infections  from  eczema  and  other  secreting  der- 
matoses. 

Kpithelioma.  acne,  furuncle,  fi.-tula.  carbuncle  izinc  ionto- 
phore-i-;  anode  of  amalgamated  zinc  "requires  a  general 
anesthetic  and  has  no  advantage  over  .c-ray"). 

Falling  of   hair,    sycosis,    tinea,    fistula'.    \-erruca    i  copper  or 

mai:ne-ium  iontophoresis  i. 
N'evus,  small  epitlielioma,   lujius.  leukojilasia.  acne  rosacea. 

KiTato-l.-,  acne,  ec/.eina   of  a   lichen   type. 
I  Kdoid.  psoriasis,  verruca. 

Electricity  in  Skin  Diseases.-    Kflluve-  from  static  or  hi<rh-tension 
liiiili-fn-fjueiicy  apparatus  are  excellent    for  erysipelas  and  suppurating 

Srli /-"'ii /'//HI  may  lie  treated  by  centra]  galvani/ation,  and  its  local- 

/'    :  !<  inns.  hi.  i-  UK  irphea  and  I  )upuyt  ren's  eoi  it  faction,  1  >y  local  galvanic 

i-urreiits.     |  -or  -cirri  idi'i'ina  eirciiniscripia.  two  electrodes  are  at  ojtposite 

"   Macharlo  - 

!':-••.•••  m  pi  Tat  I  Vi        s-      I 

"In  lup'i-  an' I  other  -km  di-ea-e-.  phot  ot  hera  py  i-  often  associated  with  tht 
r-ray-  and  l)oth  are  -ometimes  aided  liv  ->  -n-iljih/at  ion  of  the  -kin  with  eosin  or 
•  .  n  -cin. 


GALVANIC,     FARADIC,    AND    SINUSOIDAL    ELECTROTHERAPY          427 

sides  of  the  area  and  a  current  of  8  ma.  is  applied  for  twenty-five 
minutes. 

Chronic  pruriginous  eczema  has  been  successfully  treated  by  central 
galvanization,  and  so  has  herpes  zoster.  The  same  method  of  treat- 
ment of  the  spinal  cord  by  either  galvanic  or  faradic  currents  has  given 
successful  results  in  vitiligo,  ichtkyosis,  ecthyma,  pemphigus,  cutaneous 
gangrene,  prurigo,  eczema,  urticaria,  and  lichen,  all  these  diseases  being 
possibly  of  nervous  origin.  Hydro-electric  baths  are  excellent  in  all 
these  cases.  The  galvanic  current  locally  relieves  the  itching  of  lichen 
ruber. 

Perforating  ulcer  of  the  foot  has  been  cured  by  faradization  of  the 
posterior  tibial  nerve,  high-frequency  currents  (p.  583)  also  being  useful, 
and  erythromelalgia  and  symmetric  gangrene  have  been  successfully 
treated  by  the  local  application  of  galvanic  currents. 

Electrolysis  in  its  applications  to  cutaneous  lesions  is  referred  to 
elsewhere  (p.  419). 

The  resolving  effect  of  the  galvanic  current  makes  heavy  currents 
of  this  kind  valuable  in  keloid, 'mycosis  fungoides,  elephantiasis,  and  in 
cicatrices  following  burns. 

Alopecia  is  treated  by  faradization  of  the  scalp.  The  author  has 
had  excellent  results  from  the  application  of  sponge  electrodes,  but  has 
less  confidence  in  the  application  of  electric  brushes  and  combs.  The 
latter  have  their  use,  btit  it  seems  as  if  the  combing  and  brushing  could 
be  better  done  separately  from  the  application  of  the  electric  currents, 
and  as  if  a  sufficient  strength  of  the  latter  to  do  much  good  is  disa- 
greeable or  painful  if  applied  by  brushes  or  combs. 

Static  electricit]i  i-s  valuable  in  skin  diseases,  especially  on  account 
of  the  anesthetic  effect  of  the  static  breeze  or  effluve  upon  such  lesions 
as  pruritus,  eczema,  and  lichen.  The  general  effect  of  a  static  bath  is 
also  excellent  in  these  cases.  The  same  effluves  are  valuable  in  frost- 
bite, radiodermatitis,  psoriasis,  impetigo,  acne,  lupus  cri/thematodes,  and 
furunculosis. 

Static  sparks  give  good  results  in  keloid  and  other  localized  sclcro- 
dertna  and  morphea. 

Static  l>athx  and  effluves  and  sparks  have  been  recommended  for 
alopecia,  but  the  author's  experience  with  static  electricity  has  led. 
him  to  regard  it  as  an  application  which  is  rather  apt  to  cause  the  hair 
to  fall  out.  The  number  of  patients  who  have  complained  of  this 
symptom  in  the  course  of  a  series  of  treatments  by  the  static  bath  with 
an  efHuve  applied  over  the  head  makes  it  seem  as  if  it  were  not  a  mere 
coincidence.  A  number  of  static  sparks  applied  to  the  scalp  seem  a 
better  method  for  treating  alopecia  than  several  minutes'  application 
of  the  static  breeze. 

Varicose  ulcers  and  sluggish  wounds  may  be  stimulated  by  the 
application  of  static  sparks,  and  the  wound  left  after  curettage  for 
lupus  may  receive  static  sparks  as  a  germicide1. 

Pruritus  Vulvoc. — The  best  methods  of  treatment  are  by  the  .r-ray 
and  radium.  Other  valuable  methods  are  the  incandescent  electric-light 
and  the  static  breeze. 

High-frequency  Currents  in  Skin  Diseases. — This  is  described  on 
page  (521 . 

Herpes  Zoxter — Treatment  bu  Galvanic  Currents  at  an  Early  Stage. — 
At  an  acute  stage  treatment  may  be  applied  by  a  positive  electrode 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

measuring  '.'  by  1M  cm..  applied  alon<r  the  spine  at  the  level  of  the  emei 
Lrence  of  the  nerve-root s,  and  hv  a  negative  elect  rode  covering  all  the 
vesicles.      A  current   of  «>  to  >>  ma.   is  applied  for  twenty-five  or  thirty 
minutes  every  other  day.      The  disease  is  sometimes  cured  in  forty-eight 
hours,  and  without  leaving  any  subsequent  neuralgia. 

A  of*!  "/'  h,  r/i<  *  ;«.x7,  r  occurrim:  durum  a  course  of  treatments  by 
hi::h-frequency  currents  was  cured  by  Petit1  by  the  application  of  heavy 
galvanic  currents.  A  positive  electrode  measuring  \.~>  by  Hi  cm.  cov- 
ered the  posterior  roots  of  the  nerves  in  question,  while  a  negative 
electrode  of  the  same  si/e  covered  the  side  of  the  chest  and  the  three 
Lrroups  of  vesicles.  A  current  of  from  (50  to  70  ma.  was  gradually  turned 
on.  allowed  to  flow  for  ten  or  thirteen  minutes,  and  gradually  turned 
off.  There  was  some  relief  from  pain  immediately,  and  a  cure  was 
effected,  by  ei-ht  daily  treatments. 

}•' a  I'n  >icl>  N    nut!    Anthra.r     Tnattfl    In/    (fah'dnic    Current*.--  Negative 

Lialvaii.ipunct  ure  wit  h  a  current  of  .">  or  10  ma.  for  live  minutes  is  effective. 

I*    u-ua!ly  requires  the  use  of  ethyl  chlorid  for  anesthesia.      If  a  '/.'me 

needle  is  used,  the  positive  wire  should  be  connected  with  it  to  secure 

lenelil  i  if  /.me  mni/at  ion. 

X-niij  in  SL'in  llixcdxi  *.  This  is  of  the  greatest  importance,  and  is 
referred  to  on  p.  tiL'l . 

Phototherapy,  including  treatment  by  the  ultraviolet  rays,  is  in- 
valuable. 

Obesity.--- //'//m////  I nt<  rri//>t<(!  (inlr/mic  Cum  nl*.  —  These  currents 
have  a  powerful  effect  in  slowing  the  development  of  growing  and  caus- 
ing emaciation  in  adult  animals.  It  may  be  that  they  will  be  found 
Useful  in  the  treatment  of  obesity. 

Si  in  ultii  at  mis  I'"(tr(i<liz(ition  <ni<l  \  (brdtioii  in  Obesity.— One  electrode 
i-  stationary  upon  some  indifferent  part  of  the  body.  The  other  wire 
from  the  faradic  coil  ]>asse>  to  the  metal  ball  used  a>  the  vibrator,  and 
the  latter  i-  covered  with  damp  cloth.  The  current  should  be  strong 
eiKiujili  to  tetaiii/e  the  muscles.  The  coil  ha-  coarse  wire. 

Hirr/i/nn"*  Tr<  tiffin  >it  nf  ()h<  *ifi/.--  A  faradic  coil,  with  a  ratio  of 
about  1  in  the  primary  to  about  ',]  in  the  second. :r\',  i-  used,  and  the 
primary  current  is  considerable,  -ay  l",  anijx'res  ol  '_' 1  volts.  The  rate 
"f  interruption  i-  about  MO  per  second.  This  curp  nt  i-  rhythmically 
applied  100  time-  a  minute  by  means  of  a  metronome  and  after  half  the 
turn  it  i-  turned  oil  and  reversed.  Three  electrode-  pa--  from  one  pole 
i''  the  back  and  the  uiidersurfaces  of  the  thiti'h-.  From  the  other  pole 
wire-  pas.-  to  a  number  of  rheostats,  and  through  them  to  different  large 
semicyliiidric  electrodes  back  of  the  calves,  from  .if  the  thighs,  abdomen, 
and  arm-  twelve  in  all  .  These  are  held  in  place  by  rubber  bracelets  or 
l'\  -and-bati-  all  the  way  up  to  a  total  weiuht  of  •_'()((  pounds.  The  cur- 
reni  den-ii\  i-  only  .ol  ma.  per  -quare  centimeter.  A  hot  wire  mil- 
liamperemeter  -liows  a  total  current  of  '_'.")  to  MO  ma.  for  an  ordinary 
-''Hi'  tat  and  mu-cular  \\  <  'men  !'e(|Uii-mii  70  or  «S0  ma  .  Treat  men  t- 
la-t  from  twenty  to  forty-five  minute-  daily.  I)amp  lo\\'els  cover  the 
elect  rode-  and  the  patient  has  on  a  linht  dres-intr-^'oxvn.  The  liest  and 
'  :  •  p '  i  H-nt  rate  of  red  net  ion  i-  2 1  or  M1.  pound-  a  week. 

Cififtulic     l.li  r/,  ,-jitii,n     irith     Ilinni    (iulrtinic    ( '  urrt  lit*    /n    Olx.^ili/.- 
This  application   (,;,.   been   found  to  pfodtlce  a   loss  of  weight,  u'hich  i- 


GALVANIC,     FARADIC,    AND    SINUSOIDAL    ELECTROTHERAPY          429 

so  great  as  to  make  it  a  successful  means  for  treating  obesity,  and  to 
make  it  undesirable  in  cases  of  malnutrition,  debility,  or  cachexia. 
The  current  must  be  applied  in  such  a  way  as  to  avoid  shocks  or 
burns. 

Raynaud's  Disease.— Treatment  !>;/  (!<ilr<rnic  Ctmr'ntx. — This  is 
often  successful,  and  consists  in  daily  applications  of  half  an  hour's 
duration,  and  with  a  current  of  10  to  20  ma.  The  positive  plate  elec- 
trode is  placed  at  the  nucha,  and  the  limbs  affected  by  the  local  asphyxia 
are  placed  in  a  negative  bath. 

Faradization  in  Chloroform  Syncope. — A  classic  method  has  been 
the  stimulation  of  t  he  phrenic  nerve  in  t  he  neck,  the  other  electrode  being 
applied  in  the  region  of  the  diaphragm.  The  respiratory  movements 
thus  provoked  are  unilateral,  and  special  electrodes  are  required  for  the 
nerve. 

The  method  introduced  by  Yillett1  is  a  bilateral  rhythmic  stimulation 
of  the  pectoral  muscles.  The  patient's  arms  are  held  behind  his  head, 
and  the  two  electrodes  are  applied  at  the  outer  third  of  the  two  pectoral 
muscles.  A. deep  inspiration  is  produced.  On  removing  one  of  the 
electrodes  expiration  ensues,  which  may  be  assisted  by  pressure  upon 
the  sides  of  the  chest.  The  stimulation  is  applied  fifteen  or  twenty  times 
during  the  first  half-minute;  later  the  stimulation  is  made  at  such  times 
as  to  amplify  the  spontaneous  movements  of  respiration. 

Electricity  in  Incontinence  of  Urine. — Steavenson's  method  is  to 
apply  a  constant  current  of  10  or  12  ma.,  with  the  anode  at  the  perineum 
and  the  cathode  in  the  lumbar  region. 

(iuyon's  method  is  to  apply  a  faradic  current  by  means  of  an  elec- 
trode introduced  so  as  to  reach  the  sphincter  vesica1.  the  other  elec- 
trode being  at  an  indifferent  region. 

Bordier's  method  is  to  apply  static  induced  currents  by  means 
of  (Iuyon's  sound.  The  patient  is  not  insulated.  The  sound  is  intro- 
duced and  connected  with  the  external  armature  of  one  of  the  Leyden 
jars,  and  a  series  of  short  sparks  is  allowed  to  pass  between  the  prime 
conductors  of  the  static  machine.  Kach  shock  is  accompanied  by  a 
contraction  of  the  sphincter.  Treatments  last  five  minutes  and  are  not 
painful.  Two  applications  a  day  are  best  at  first;  later,  one  applica- 
tion a  day. 

Marques'-  uses  a  little  different  method.  He  applies  a  cylindric 
neirat  ive  elect  rode  covered  with  wet  cotton  to  the  vulva  and  t  he  u  ret  lira  1 
orifice  in  irirls.  or  to  the  perineum  in  boys,  while  the  positive  electrode  is 
applied  over  1  he  hypogast  rium.  A  constant  current  of  10  ma.  is  applied 
for  ten  minutes,  and  this  is  followed  by  twoor  three  minutes'  application 
of  the  same  strength  of  current  interrupted  sixty  times  a  minute  by  the 
metronome  (the  rhythmic  rheotome  used  by  the  author,  p.  4S(.),  is  a 
simple  device'). 

Istildlcil  Induction  Shncks  for  Jncovtim  nc<  of  I 'rim. — Rockwell1'1 
believes  that  better  results  are  obtained  with  these  than  with  galvanic 
currents.  One  electrode  is  placed  upon  the  abdomen  or  sacrum:  the 
other  is  applied  to  the  perineum  in  very  younii  children,  but  better 
reMilts  are  obtained  when  an  olivary  electrode  can  be  introduced  into  the 
urethra  and  the  current  applied  to  the  external  sphincter.  Separate 


430  Mi.nn  \i.   i:i.t.<  THK  ITY   AND  KOXTCKN  KAYS 

>iiocks  from  a  faradic  coil  with  coarse  wire  and  a  strong  enough  current 
to  produce  strong  muscular  contractions  are  applied  at  the  rate  of  one  to 
five  per  second.  Daily  applications  of  about  live  minutes  are  made  at 
tirst.  but  later  they  need  not  be  so  frequent. 

S/>ns>n  of  tin  AV// /•/<(//  Sj>liinct<  r  of  (In  I'rttlira. — This  may  be  treated 
by  a  rectal  electrode,  usini;'  a  faradic  current  with  very  slow  interrup- 
tions, coarse  wire,  and  a  very  weak  cui'rent:  or  the  positive1  galvanic 
current  or  hidi-frequency  currents.  Static  electricity  is  useful  in  neur- 
ast  lieiuc  cases. 

Spasmodic  Stricture  of  the  Esophagus. — This  condition  is  treated 
by  faradization  applied  bv  means  of  an  esophaireal  elect  rode,  and  one  at 
some  indifferent  place.  A  series  of  currents  may  be  applied  to  pro- 
duce million-  of  deglutition,  and  in  this  way  to  relax  spasm.  A  coarse 
wire  coil  and  slow  interruptions  are  used  with  a  modi-rate  strength  of 
current . 

Percutaneous  Electrization  in  Gastric  Diseases.  A  considerable 
number  of  observers  doubt  the  efficiency  of  intraji'astric  electrization, 
and  it  is  certain! v  difficult  to  apply,  us  well  as  disagreeable  to  t  he  patient. 
By  percutaneous  electrization  is  meant  the  influence  upon  the  stomach 
from  electric  applications  made  to  the  skin  cvei  that  ortran. 

SirrtfiH-'/  function*  are  best  influenced  by  faradization.  One  elec- 
trode i-  -labile  at  some  indifferent  point,  and  the  other  is  labile  over 
the  gastric  area.  A  fine  wire  coil  and  rapid  interruptions  are  used  with 
the  strength  of  cui'rent  which  proves  most  agreeable  to  the  individual 
pat  lent. 

Motor  function*  are  influenced  by  ^alvanofaradizat  ion.  and  the  best 

wav  of  appivinji  it  i-  bv  means  of  t  he  rhythmic  rheostat  and  pole  changer 

described   on   p.    ISH.       (.^uite  laril'e  electrodes   arc   used.       One  covers  the 

LTa>tric  area,  and  the  other  is  between  the  shoulder-blades.      A  galvanic 

current   gradual  1\~  lie-ins  to  flow  in  one  direct  ion,  and  at  t  a  ins  a  st  ren.irth 

n!  _'i  i  ma.,  and  then  gradually  diminishes  to  zero,  and  gradually  attains 

a  -tren^th  of  I'D  ma.  in  the  opposite  direction.      The  same  changes  take 

plac1   in  t  he  farad  ic  current .  but  the  change  in  si  remit  h  is  more  im  port  ant 

':.  .:.   the  chatme  m   polarity.      The  faradic  coil  should   have  coarse  wire 

iiid  -lo\\    vibrations,  and  the  strength  of  the  current  should  be  such  as 

to  ran->-  marked  contraction  of  the  abdominal  muscles  at   the  height  of 

e  of  current.      The  oscillations  of  the  current   take  place  at   the 

ra1'-  o!  from  I  went  y  to  sixt  v  a  minute,  depending  upon  t  he  sens  at  ions  of 

i  ii  ni . 

M'''  'ions    are    al-o    favorably    influenced    bv    the    static    m- 

,     •  nt.      The  external    armature  of  the    Leyden  jar  at    the  posi- 

|e(l.  while    the    oilier    is    connected    with    a    metallic 

•!i-ct  [-1  ide  ajipln  ;  to  t  he  skill  of  1  he  epiirast  ric  region.  The  pal  lent  is 
The  -park  rod-  of  the  static  machine  are  from  '2  to  (i 
i  he  machine  i-  regulated  to  produce  seven  or  eiirht 
,.  I'ordier  make-  t  he  applicat  ion  to  1  hree  principal  points: 
e.  a  lit  1  le  above  i  IK-  umbilicus:  _'  a  couple  of  inches 

'    '  hi     •     -  dlall   line  and   a   little  above  the  level   ol    the  limbiliclls  : 

-    'he  left    anterior  siiperioi    -pine  oi   the  ilium.      Strong 
rciir,    and    the   patient    feels   a   shock   at    each   spark 
LMUL:    rod-   ot    the   static    machine.      Tin-   treatment 
ites.   and    i-   L:  veji   evi     '     da'     n|    i  -vi  -rv   i  >'  her 
'  :  .hi    -iomach  is  cured  m  six  \\  eek-  01  -<  >. 


GALVANIC,    FARADIC,    AND    SINUSOIDAL    ELECTROTHERAPY         431 

Sensory  functions  of  the  stomach  arc  favorably  influenced  by  gal- 
vanic currents,  and  surprisingly  heavy  currents,  100  or  200  nut.,  have 
been  recommended  by  sonic:  authors.1  Much  weaker  currents  should 
generally  be  employed. 

The  Influence  of  Intragaxtric  Electrization. — Freund'-'  lias  made  a 
series  of  observations  from  which  he  concludes  that  no  specific  secretion 
is  excited,  but  that  a  thin,  more  or  less  acid  mucous  secretion  takes 
place. 

Atonic  Dyspepsia. — This  may  be  treated  by  intragastric  rhythmic 
galvanic  currents  or  galvanofaradization. 

Galvanic  Currents  Applied  to  the  Pneumogastric  Nerve  in 
Stomach  Troubles. — An  electrode  may  be  applied  over  each  pneumo- 
gastric  nerve  at  the  base  of  the  neck,  and  a  current  of  o  or  10  ma.  is 
applied  for  five  minutes,  with  occasional  reversals.  This  may  cause  the 
disappearance  of  nausea,  vomiting,  and  regurgitations  in  cases  of  dys- 
pepsia, with  symptoms  suggestive  of  cancer. 

Electricity  for  Habitual  Constipation  and  Membranous  Colitis. 
— Slight  cases  yield  to  the  static  bath,  static  breeze,  or  static  sparks 
in  the  iliac  fossa'.  The  sparks  are  for  the  atonic,  the  breeze  for  the 
spasmodic,  variety. 

(Irave  cases  of  atonic  constipation  may  be  treated  by  faradiza- 
tion, rhythmically  reversed  galvanic  currents,  or  the  Morton  wave  cur- 
rent. These  may  be  applied  to  the  skin  or  to  the  skin  and  intestine. 

Grave  cases  of  spasmodic  constipation  and  enterocolitis  are  greatly 
benefited  by  faradogalvanization.  The  galvanic  current  is  about  100 
ma.,  and  is  not  interrupted  or  increased,  the  faradic  current  being  a 
mild  one  from  a  coil  of  fine  wire.  One  very  large  electrode  is  over  the 
abdomen,  and  another  is  over  the  back. 

Rectal  vibration  either  internal  or  external  may  be  used  for  relaxing 
sphincters. 

Fine  long  wire  faradic  coil  stimulates  peristalsis.  Coarse  faradic 
coil  does  not  ( De  Kraft). 

Faradization  over  course  of  the  colon  produces  prompt  evacuation 
of  the  bowels.3 

Nervous  state  with  fecal  retention  but  daily  movements.  To  ma. 
ordinary  galvanic  current  may  be  applied  for  one  to  two  and  a  half 
hours  at  first  t.  i.  d.,  then  b.  i.  d.,  then  once  a  day.  Of  course  it  must 
be  applied  and  turned  off  gradually. 

Intestinal  stasis  is  benefited  by  the  slow  surging  galvanic  current 
for  twenty  minutes  followed  by  vibration  for  two  minutes.4 

For  an  effect  on  the  liver  one  may  use  the  slow  sinusoidal  current 
with  a  sand-bag  over  the  electrode  if  the  static  wave  current  is  not  avail- 
able. The  same  current  is  used  for  atonic  constipation,  with  the  pos- 
terior pad  over  the  first,  second,  and  third  lumbar  vertebrae,  and  for 
spastic  over  the  eighth  to  eleventh  dorsal  (Morse,  see  page  430"). 

For  constipation;  to  strengthen  abdominal  muscles,  fairly  large 
sized  electrode  on  the  back  over  spinal  nerve  supply  and  smaller  elec- 

1  Ruhinovici,  Those  do  Paris,  1907. 

-'  Arch.  f.  Patliol.  a.  Physiol.,  May.  190."). 

3  Livingstone,  Amor.  .Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi,  Xo.  1, 
January,  191S,  p.  20. 

'Martin,  Amor.  Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi,  Xo.  9.  Sep- 
tember, 191S,  p.  21)."). 


MKD1CAI.    KI-KCTKinTY    AND    RONTUEN    KAYS 

trodes  in  front  over  the  ascending  and  descending  colon  using  a  bifur- 
cated cord  or  changing  the  position  of  the  electrodes  apply  surging 
electric  impulses  Mor-'\  see  paue  439\ 

The  sigmoid,  either  for  impact  ion  or  gaseous  distent  ion,  is  treated  by  a 

curved  rectal  electrode  passed  well  up  into  sigmoid  and  a  smaller  sur- 
face electrode  over  it.  A  heavy  long  contractile  effect  having  not  over 
2(1  suruinu  wave  impulses  per  minute  (Morse,  see  page  439). 

Postoperative  areas,  muscles,  and  nerves  severed  or  weakened  by 
lonu-continued  use  of  abdominal  belts  are  treated  by  Morse  surging 
current  -.! 

Massev  -ays  that  the  currents  from  Morse's  apparatus,  like  all  other 
small  induction  currents  (faradic,  Malic  wave),  are  all  probably  an  ex- 
ceedingly -mall  fraction  of  a  second  in  their  rise  and  duration.  These 
do  not  reach  deep-seated  orgau>  in  sufficient  volume  to  do  the  work  of 
producing  contraction  in  deep-seated  involuntary  muscles.  Massev 
uses  kaolin  electrodes  1  inch  thick  with  a  backing  of  sheet  metal  2 
inches  -mallei-  all  around.  A  slow  sinusoidal  current  of  200  ma.  on  a 
pad  the  sixe  of  the  crown  of  a  man's  head  anteriorly  and  considerably 
larger  In-low  the  shoulders  posteriorly  is  not  too  much  current  in  many 
cases  of  lariie  abdomens  or  where  there  is  much  fat.  This  is  applied 
for  twenty  to  thirty  minutes,  avoiding  too  much  heat  by  having  alter- 
nat  ion-  considerably  more  than  12  to  the  minute,  1")  is  right,  or  oO  waves. 
The  current  he  uses  is  t  he  same  as  t  he  aut  hor's  (see  page  4Mi .  His  be- 
irmnini:  do-e  i-  .">()  ma.  for  thin  persons.  Contraindication  to  galvanic 
current  is  found  in  malignant  conditions. 

l)inrrhi a  yields  to  application-  of  ulass  vacuum  electrodes  from 
!  he  i  ludin  resonator  applied  over  the  Mirface  of  the  abdomen. 

A'.'-.',/.';,;-',,,,  i-  also  excellent:  a  very  la  rue  electrode  covers  the 
abdomen.  ::|i(l  another  the  lumbar  reuion.  '1  he  current  is  from  the 


•   •  •    I  ilinu;  di  i  he   abdominal  muscles,  not  a  tetanic  con t  ract  ion. 

A   rii.--i    nf    .    -,    ,    rli  ••!,,,',<•  rufiti*  mnl  (/'/*i  titi  i'-i   successfullv   treated   bv 
^h-fr<'i[Uency    current-  irom   \\-ICUUMI    electrodes    is   de- 
d  on  p.  I'do. 

/•.'/,,'•>  1i,li*tintil  J)tiiirJn'H.-    The  -troimcr  currents  are  useful  in  in- 
'      til          li-truction  and  occlu-ion  and  in  lead  colic.      They  are  regarded 
ru'ency   treatment,   intended   to   provoke  a   mox'eitKMit    of  the 
bowel-    at    any    co-t .       T!ie\-   are    not    -uitable   for   repeated   application 
y  v/Mijld  pi'iHJuee  -pa-modic  constipation. 

•     .'    ent    i-    a    sofi -ruliber   rectal    tube,    \\-hich    covers 
0    transmits    the    liquid.      N'n    pan    of    the   nx'tal 
'    i-t         ih    the   fle-h.       I-'rom    1    in    1  '.     pint-    of   salt    water 
V     •    ectrodc   measuring   abmit    ~>  by   'i   inches   is   placed 
•    i-n,      •    :    '     '•''!.-•  :\  nt    current    of  about    .'in  or    H  >   ma.   is 
,  •  .      Then    i  he    current    i.-    -uddenl  v    revj-rsed.    and 

1 1    ilirect  ion  In]  one  or  i  uo  nnnut  es.      Tin  'se 
o!  con-taut    flow    al'e  kept    up  foi    '  went  v  or  t  hirt  y 
•  iii    ':  av   tin  n   try   to  ha\'e  a    moveiiK-nt.      This  mav 
,    bin     the    etlect    i-    -itmetime-    delaved    for    -e\'eral 


KA1.VAXIC,     KAUADIC,    AM)    SINTSOIDAL    KLH(  'TK<  (THKKAI'Y 

present  in  the  rectum,  hut  failing  to  stimulate  evacuation  is  successfully 
treated  by  electric  douches  with  the  external  electrode  sometimes  over 
the  sigmoid  flexure  and  sometimes  over  the  cecum.  The  current  flows 
in  the  same  direction  for  ten  minutes  before  being  gradually  reversed. 

The  Apostoli  Method  for  Uterine  Fibromyoma.  The  author 
of  the  method  called  it  elect  rochemic  cauterization  of  the  mucous 
membrane,  and  the  results  lie  obtained  were  the  production  of  a  new 
and  healthy  mucous  membrane,  with  a  greatly  reduced  tendency  to 
hemorrhage  and  often  a  reduction  in  the  size  of  the  fibroid  tumor.  He 
irave  the  present  writer  an  opportunity  to  examine  some  of  his  cases  in 
Paris  in  IS'.H.  The  tumors  had  become  much  smaller,  and  there  was  a 
symptomatic  cure.  Complete  disappearance  of  uterine  fibromyomata 
under  this  treatment  occurs  in  only  about  10  per  cent,  of  the  cases 
I  rented. 

A  galvanic  current  of  (it)  or  7(1  ma.  is  usually  employed,  but  in 
certain  cases  as  weak  as  'JO  or  .'•>()  ma.  or  as  strong  a  current  as  100  ma. 
n!'  more  is  used.  The  act  ive  positive  electrode  lias  a  platinum  or  carbon 
olivary  tip  and  an  insulated  stem.  It  is  applied  successively  to  all  parts 
of  the  mucous  membrane  of  the  body  of  the  uterus,  but  the  internal  os. 
the  cervix,  and  the  external  os  are  protected  to  avoid  the  risk  of  cica- 
tricial  contraction.  The  indifferent  negative  electrode  is  usually  a  large 
(•lay  or  kaolin  electrode  placed  over  the  abdomen.  The  application  lasts 
about  five  minutes.  Besides  the  electrolysis  of  the  mucous  membrane 
there  is  a  trophic  effect  upon  the  Tumor  tending  to  cause  a  return  to 
normal  conditions.  The  latter  effect  is  best  obtained  in  intramural 
and  submucous  fibromyomata.  Sub  peritoneal  tumors  are  often  very 
little  affected  by  the  current  from  an  hit  ra-uterine  electrode,  (lalvano- 
puncture  is  suitable  for  some  of  these  which  are  suprapubic  or  which  can 
be  reached  through  Douglas's  cul-de-sac.  Care  is  taken  in  each  case  to 
avoid  coils  of  intestine  and  to  apply  the  current  exclusively  in  the  sub- 
stance of  the  uterus.  The  needles  are  to  be  insulated  where  they  pierce 
the  vagina  or  skin  and  the  parietal  and  visceral  peritoneum. 

The  Final  Rtxnltx  of  l/n  Electric  Tnnh/unt  »f  I'tcri-nc  Fihmn/ti. — 
Massey1  has  traced  the  results  for  three  years  after  treatment  in  101 
cases,  among  them  were  IS  cases  in  which  the  tumor  had  disappeared  ; 
'_'(')  cases  were  failures. 

Interstitial  hemorrhagic  fibroids  are  the  most  favorable,  and  the 
submucous  variety  also  yield.-  good  results.  The  subserous  variety, 
especially  if  pedunculated.  are  less  certain.  Fibroids  complicated  by 
pyosalpinx  and  other  stippurative  or  inflammatory  conditions  are  not 
entirely  safe  to  treat  in  this  way. 

At  the  present  time-  the  Apostoli  method  is  considered  less  desirable 
than  treatment  by  radium  or  the  Kbntgen  rays. 

Electricity  in  Sterility  Due  to  Atrophy  or  Imperfect  Development  of 
the  Uterus.— Rhythmic  unduiatory  galvanic  currents  with  alternations, 
applied  from  an  abdominal  electrode  and  a  vaginal  or  r.n  int  ra-utenne 
electrode,  and  a  maximum  strength  of  1")  ma.,  are  excellent.  The 
author  has  had  success  also  with  high-frequency  currents  applied  from 
a  vaginal  vacuum  electrode  with  a  double  stem,  which  insulated  all 
but  the  portion  in  contact  with  the  cervix  and  Douglas'  culdesac. 

Persistent    purulent    catarrh    of    the    uterus    is    about    the    only    in- 

.  Assoc.,  Mav  L'l,  1904. 


l->l  MKDICAL    KLKCTHIcrrV    AM)    KO.NTGKX     HAYS 

dication  for  an  intra-uterine  electrode.  For  that  Massey  uses  mercuric 
ca'aphoivsis  with  a  moderate  current. 

De  Watteville  or  Faradogalvanic  Currents  for  Menorrhagia  and 
Enterocolitis.  A  positive  electrode  is  placed  over  the  lumbar  region, 
and  a  la  rue  negative  one  over  the  abdomen.  The-  galvanic  rheostat 
indicate-  UK)  ma.,  and  the  t'aradic  current  is  from  a  coil  of  line  wire. 
The  application  lasts  a  Unit  ten  minutes. 

Electric  Treatment  of  Asthma.  —  The  positive  electrode  is  the 
active  one.  and  measures  'J'.  inches  in  diameter.  It  is  placed  first  on  one 
side  o:'  tiie  neck  and  then  on  the  other:  then  at  the  side  of  the  trachea, 
and  then  at  the  lower  attachment  of  the  sternomastoid.  Jt  is  moist- 
ened \\ith  plain  warm  water.  '1  he  negative  electrode  is  a  larger  one. 
and  i-  placed  eit  her  at  the  nape  of  t  lie  neck  or.  in  a  case  of  tuberculous 
psi  ido-aslhma.  it  may  be  placed  over  the  upper  part  of  the  lung  in 
of  the  chest.  The  strength  of  the  curix  nt  is  from  10  to  15  ma.. 
lay  be  rhythmically  changed  from  xero  up  to  this  strength.  This 
oscillation  should  take  from  five  to  six  seconds.  The  treatments  last 
from  ten  to  fifteen  minutes,  and  may  be  applied  two  or  three  times  a 

Week. 

Expectorant  Effect  of  Galvanic  Currents.  The  negative  elec- 
trode  i-  placed  at  the  back  of  the  neck,  and  the  positive  first  on  one  side 
and  then  on  the  other,  at  the  border  of  the  scaleni:  or  the  positive 
may  be  branched  and  lead  to  an  electrode  on  each  side  of  the  neck. 
The  current  is  to  be  '2  or  •'!  ma.  wit  h  one  anode,  or  4  or  ^  ma.  wit  h  a  double 
anode,  and  is  to  be  a  constant  current  for  about  three  minutes. 

Stembo'  has  found  that  this  application  will  provoke  cough  and 
profuse  expectoration  where  med;"ines  fail.  He  has  used  it  successfully 
m  bronchitis  and  bronchopneumonia. 

Ear  Diseases.  -Stimulation  «f  tJn  F/ici/il  \(/-r<  in  f}/<  K.vtrrnal 
.\  'itl'tnT'i  ('mnif  for  l)r/i  Ol/lis  Mi<lin.  •—  Rhyt  hmic  faradization  strong 
enough  to  cause  conn-action  of  all  the  facial  muscles  is  supposed  to 
e\ercise  1  he  muscle  of  the  atrium,  and  consequently  prevent  ankylosis 
oi  •  he  art  iculat  ions  of  t  he  ossicles.  According  to  Bergonie  and  Jioques,'-' 
this  treatment  often  improves  the  hearing. 

I!  ir  t  hmic  ualvam/at  ion  acts  in  the  same  way. 

unit-  Currrtitx  in   fcnr  [)i*<  n.«  *.-  The  negative  electrode 

-  '    olive  electrode  with  a  flexible  insulated  stem:  it   is  passed  through 
;ii     I.  i-'achiaii  catheter  into  the  middle  ear.      The  positive  electrode  is 
app  led  ai   any  indifferent    place,  such  as  the  hand.      A  current  of  from 

-  'o  i)  ma.  i-  applied  for  five  or  ten  minutes.      It  should  be  t  urned  on  and 

-!  i']  lai   '.       I  ubot  vmpaiiil  is    at    all    stages    and    hvperplastic    otitls. 

inn  in  the  ears  are  tin-all  y  benefited.      The  treatment 

1    •    •      •    •'      :  MI    i  he  auditory  nerve  and   the  cerebral  cent  ers.      The 

•  •  •  '  •'    of  i  h  vert  igo  would  lie  an  indication  for  cant  ion  as  to 


[.eiiihinn     Ke-teyerr    find-    that     ionic    medication    in    ear    diseases 

ca  ;-—    especially    a    sclerolytic   effect.      "l.a\"    the    patient's    head   side- 

\\  ays  on  'a  MI  .  till  t  he  external  am  hiory  meat  us  wit  h  a  sol  ut  ion  of  zinc 

1  '        i  IM    current  bv  mean-  ot  a  wire  insulated  to  its  tip  which  is 

•  '    cotton;  apply  '.>  or   I  ma.  with  occa-ional  change 


(iALVAXIC,     FAUADK',    AM)    SINUSOIDAL    KLKCTKOTHKKAI'Y  435 


in  direction,  five1  e>r  te'ii  minutes  in  acute  cases  e>r  twenty  minute's  in 
chronic  cases  of  otitis  media.  Acute  pain  is  relieved  in  a  few  minute's. 
Functional  e  leaf  ness  of  nervous  exhaustion  responds  to  two  or  three  1  ivat- 
ments  plus  a  little1  faraelism."  Acute  mastoiditis  vanishes  if  treated 
early.  The  electrode  is  wet  with  j,1,,,  mercuric  iodiel,  5  ma.  are-  applied 
over  the1  mastoid  process  for  one-half  to  one1  and  one-half  hours  morning 
and  ('veiling.  In  purulent  otorrhea  zinc  ioeliel  ioni/ation  lessens  the1 
leiikoe'ytes  and  lymphocyte's.  Alum  (2  per  cent.)  is  used  for  ioni/ation 
in  relaxation  of  the  tympanum.  Arsenic  ionization  is  beneficial  for 
tuberculous  middle-ear  trouble1.  For  aural  vertigo  due  to  labyrinthine1 
loss  of  couple,  iodin  ionizations  are-  used,  the1  positive  pad  being  behind 
the1  mastoid,  5  ma.  is  applied  for  a  half-hour  every  other  day  for  one  or 
two  wevks. 

For  pain  in  the1  mastoid,  cocain  or  morphin  ionization  is  used. 
A  case  of  goiter  which  refuses  x-ray  or  radium  may  be1  treated  by  an 
aluminum  anode  0  x  1|  inches,  four  thicknesses  of  lint,  5  per  cent, 
zinc  ioelid,  15  ma.  for  one  hour.  For  ioni/ation  of  the'  Kustachian  tube 
use  a  cathe'teT  closed  at  the1  end  but  with  lateral  perforations  for  the  last 
\  inch.  The*  external  enel  is  joined  to  a  fine1  tube1  holding  potassium 
iodiel  solution  with  a  fine  wire  carrying  3  ma.  current;  five-minute 
seances  being  suitable  for  tinnitus.  Prostatic  hypertrophy  may  be 
treateel  by  ionization  under  a  local  anesthetic. 

Nerve1  pain  due1  to  dry  middle-ear  catarrh  is  treated  by  250  watt 
carbon  filament  bulb  over  mastoid  and  Yates'  static  brush  discharge1  to 
both  ears  (Hirsh). 

The  Yates  Method  of  Treating  Deafness  (Herbert  F.  Pitcher).— 
From  the  negative1  pole  of  the  static  machine1  the1  ball  spark  electrode 
moiste'iied  with  warm  water  is  pressed  firmly  against  the1  worst  ear. 
From  the1  positive1  pole  a  multiple  point  elect roele  is  held  close1  enough 
to  the  other  ear  (2  or  3  inches)  to  produce  an  efrluve.  The  discharging 
rods  are  widely  separated;  the  strength  of  the  current  is  regulated  by  the1 
speed  of  the1  motor.1 

For  de'afness  Neiswanger  use's  a  single'  elect  rode  with  terminals  to 
insert  in  the  canal  of  cae-h  ear  (Mclntosh  Co.  of  Chicago),  covered 
with  cotton  moist  ene'd  with  a  saline'  solution,  and  through  these  the 
wave1  current  is  applied. - 

Middle-ear  disease  has  been  treated  by  D'Arsonval  and  Oudin 
methods  combincel  (S.  St.  .John  AYright:i).  An  insulated  wire1  bare1 
at  both  tips  touches  the  mouth  of  the1  Kustachian  tube  and  protrueles 
from  the  nostril,  where  it  touches  a  glass  vacuum  electrode  from  the1 
Oudin  resonator.  The1  operator  holds  an  electrode  from  the  D'Arsonval 
coil  in  his  hand,  of  which  e>ne  finger  te>uches  the1  mastoid  process  or 
the  external  auditory  meat  us.  The1  current  is  not  to  be  strong  enough 
to  cause  any  sensation.  Frontal  sinus  infe-ction  is  treated  in  the  same' 
way,  one1  wire  is  in  middle'  mealus  of  the1  nose1,  external  cord  tip  at  fore- 
head. The1  tear  duct  is  treated  through  the  inferior  mealus;  the  anterior 
et humid  cells  through  the  middle  mealus.  the  posterior  through  the 
superior  meatus.  The  sphenoidal  cells  are  treate-d  through  the  middle 
or  superior  meatus,  while  the1  other  wire  leads  to  a  moist  cle>1h  at  the 
rear  of  the  vertex. 

1  Amer.    .lour.    Klectrothorapv    ami    Radiology,    vol.    xxxvi,    No.    9, 
191  s,  p.  •_>:,!. 

-  Ibid..  Xo.  9,  September,  191s.  p.  •_>.":>. 
Ibid..  Xo.  9,  September.  191s.  p.  2.">7. 


i:'>»i  MKIMi  Al.    K!.K<  TKK   ITY    AM)    HO.VH  ,  K.\     KAYS 

'I'he  fallopian  tubes  are  treated  first  by  a  vacuum  (  )udin  electrode 
a-  an  antiseptic  and  a  metal  1)  Arson val  electrode  over  the  hypogas- 
trium  for  fifteen  minutes,  then  int  racervical  glass  vacuum  electrode  and 
I )'. \r-on  val  over  fallopian  tube  seven  minutes.  For  peri  met  rit  is  copper 
insulated  rectal  electrode:  also  for  prostatitis  and  seminal  vesiculitis, 
and  some  cases  of  appendicitis.  (Jail-bladder  covered  by  a  metal  plate 
touched  by  (  Midm  vacuum  electrode.  D'ArsoilVtll  electrode  on  the  back. 

Samuel  .1.  Harris'  reports  success  in  the  electric  treatment  of  eye 
diseases.  For  ua lvalue  and  sinusoidal  currents  the  indifferent  elec- 
trode i-  a  Mor-e  pad  placed  at  the  nape  of  the  neck,  or  the  patient's 
head  may  rest  upon  it.  The  active,  usually  the  negative,  electrode 
terminal*'.-  in  two  eye  cup-  filled  with  absorbent  cotton  wet  with  a  suit- 
able -olution  and  pressed  against  the  closed  eyelids.  This  techmc  is 
with  from  _'  to  .">  ma.  for  ten  minutes  in  the  acute  cases  and  from  ~>  to 
ID  ma.  for  i  ho-e  ihat  are  chronic,  lodid  solu'ionsare  most  commonly 
employed  when  loni/ation  is  required. 

The  li-i  of  lc-ions  benefited  includes:  Ptosis:  conical  opacities: 
cornea!  ulcers :  irit  i-  in  this  use  positive  galvanism  for  its  anodyne  effect 
until  the  painful  -taue  has  passed):  glaucoma:  cataract,  spontaneous 
and  traumatic:  optic  nerve  atrophy;  muscular  imbalance;  eye-strain. 

I- or  pterygium  the  electrolytic  needle  is  thrust  into  the  apex  of  the 
iiro\\  i  h  and  a  current  of  2  or  o  ma. is  allowed  to  flow  for  al  >out  five  minutes. 
Three  or  four  days  later  the  last  of  the  growth  is  treated  in  the  same 
way.  Several  treatments  are  required. 

The  r-ray  and  high-frequency  currents  are  used  in  scleritis. 

Phototherapy  through  glass,  to  arrest  ultraviolet  rays  while  allow- 
ing liii'ht  and  heat  to  pa-s.  is  used  to  produce  hyperemia  and  increased 
nutrition  of  the  lens  in  incipient  cataract. 

Galvanofaradization  in  Lumbar  Sprains.-  A  negative  electrode 
mea-urinir  '•>  by  .">  inches  is  applied  to  the  muscles  of  the  lumbar  region, 
and  a  -imilar  one  to  the  insertion  of  the  glutei. 

'I  hf  ualvanic  current   i-  10  or  12  ma.,  and  the  faradic  coil  with  fine 

Fleet  ric  -timulation  of  the  abdomen  is  useful  in  the  treatment  of  ar- 
f '-rial  hypert cnsion.- 

Sinusoidal  Currents  for  Dyspepsia.-  Two  wet  electrodes,  ti  by  4 
inehc-.  are  fa-tened  at  eillier  -ide  of  the  uinliilicus  and  the  sinusoidal 
1  '  p.  !.;|(  i-  applied  for  fifteen  or  twenty  minutes. 

HYDRO-ELECTRIC  BATHS 

-  which  -imply  form  the  electrodes,  as  in  the  four-cell  bath, 
'•     oil!;,         word    at    this    place.      The    li(|iiid    may   be  a    very   weak 
-odium    chloiid    with   a    -mall   amount    of  glycerin   added   to 
p."    •  01    i  if  the  -kin  .it   the  surface  of  the  liquid.      If  no  such 

precaution    :     taken,   a    ring   of   redness   i.-   produced   around   the   limb, 
iid    liquid.      It    i-  apparetitlv  due  to  oxidation. 
i/.e  bandage  extending  an  inch  or  t  \\'o  above 
•    liquid  v.ili  al.-o  prevent  tlu-  irritation.      Baths 
"id    principally    as    a    very    convenient    means   of 


GALVANIC,    FAKADIC,    AND    SINI'SOIDAL    KLKCTROTIIKKA  PY 


437 


supplying  a  perfect  contact  over  ;i  large  area  for  the  transmission  of 
rather  heavy  currents,  hut  not,  as  a  rule,  for  the  heaviest  currents. 

B.  Single  large  baths  (Fig.  201  )  in  which  both  the  electrodes  dip  into 
the  li(|uid  and  in  \vhich  the  patient's  body  is  immersed,  cause  the  trans- 
mission of  a  part  of  the  current  through  the  patient,  while  about  twice 
as  large  a  part  passes  through  the  liquid  from  one  pole  to  the  other. 
The  liquid  may  be  plain  warm  water.  The  addition  of  a  little  sodium 
chlorid  or  sodium  bicarbonate,  or  any  other  medicinal  substance,  in- 
creases the  conductivity  of  the  liquid  and  reduces  the  proportion  of 
the  current  which  passes  through  the  patient.  The  electrodes  had  belter 
be  flat  pieces  or  copper  or  carbon  enclosed  in  a  lattice  work  of  china  to 


1 


prevent  contact  with  the  patient.  The  tub  may  be  made  of  wood,  glass, 
or  porcelain,  an  ordinary  metal-lined  tub  being  unsuitable.  There 
should  be  no  metal  outlet  pipe  connected  with  the  ground — it  should 
open  in  the  air.  The  inlet  pipes  should  not  dip  into  the  liquid.  It- 
should  be  possible  to  place  the  different  protected  electrodes  close  to  the 
nucha.  one  or  both  shoulders,  one  or  both  hips,  one  or  both  knees,  or  the 
feet .  Several  electrodes  of  different  si/es  and  shapes  will  be  found  useful. 

The  bath-tub  may  be  made  of  perfectly  enameled  iron.  There  must 
be  no  bare  spots  of  metal  exposed  to  contact  with  the  liquid:  practically 
all  the  current  would  travel  through  the  metal  instead  of  the  patient. 

A  wooden  or  enameled  iron  bath-tub  has  one  advantage  over  stone  or 
porcelain.  Tin1  latter  feels  stone-cold  to  the  patient  wherever  his  flesh 
touches  it.  while  the  two  former  a-sume  the  temperature  of  the  water. 

A  General  Bath  Divided  by  a  Diaphragm  (Fig.  'J'l'Ji.-  This  is  an 
expedient  which  is  not  apt  to  give  much  satisfaction.  The  idea  is  to 
have  two  portions  of  liquid  separated  bv  a  pa!'' it  ion  with  a  hole  through 

which   the   patient's   hodv    passes,   but    around    which   the   partition    i- 

. 
hermetically   scaled.      Klectrodes  dip  into    the   two    portions   of   liquid. 

and  the  entire  Mrength  of  the  current  is  supposed  to  pass  through  the 
patient 's  bodv. 


T>S  MKIHCAI.    Kl.KCTHICITV    AM)    RON'TCKN"    KAYS 

It  is  sometimes  desirable  for  the  patient  to  hold  one  electrode,  which 

may  he  a  metal   handle,   laid   across  the  bath-tub,  and  upon  which  his 
hands  m:'v  re>t.      'I  lie  oilier  elect  rode,  which  may  he  single  or  multiple, 


dip-  into  tin-  water.      It  may  be  placed  near  any  part  which  it  is  desired 

e  •]  lecially  1  o  affect. 

The  switch-board  for  electric-bath  currents  should  be  so  constructed 
that  placing  metal  plugs  in  different  holes  will  connect  the  cathode 
\\ith  any  or  all  of  the  different  electrodes,  and  the  same  way  for  the 
anode.  For  instance,  the  negative  wire  may  be  connected  with  the 
rodes  near  both  hips,  and  the  positive  wire  with  the  bar  electrode, 
on  \\liich  both  hands  rest,  or  the  negative  wire  may  be  connected  with 
a  single  large  electrode  near  the  feet,  and  the  positive'  with  one  near 
i  lie  shoulders. 

A  shovel  electrode  with  an  insulated  handle  is  useful  for  localizing 
t  he  current  -  Fig.  2(.)o).  It  is  connected  with  one  pole  ol  t  he  bat  t  (My  and 


can  be  held  in  the  water  close  to  any  part  of  the  body,  while  the  other 
electrode  rests  in  >oine  other  part   of  the  water. 

A  niilliamperemeter  is  required  to  measure  currents  up  to  ;•>()()  ma. 
for  mo-!  ordinary  purposes;  and  up  to  -  amperes  in  a  bipolar  bath  of 
tan-bark  -olut  ion  and  ot  her  medicinal  >olut  ions.  The  electric  resistance 
ot  t  he-e  solutions  i-  >o  -mall  that  a  much  larger  fraction  of  i  he  current 
will  pa--  throuu'h  ih"  liquid,  and  a  stronger  total  current  is  required 
in  order  to  tran-mit  the  u-ual  amount  through  the  body  of  the  patient. 
i  doe-  not  applv.  however,  when  the  patient  holds  one  electrode 
i-  out  "l  the  bath-tub.  'I  hen  all  the  current  indicated  bv  the 

•     piTt-mel  r|     l  p;i  Ver>eS    1  lie    pa  I  lent  '.-    bodv. 

Faradic  or  Induced  Currents  for  Electric  Baths.     The  ordinarv 

:  i  -a  '   resist  a  nee  lor  I  his  work.  o\\  ing  to  the  1  hoiisands 

through    which   the  secondarv   current    must    pass. 

I  : .'•  in  '   ,-  coi;-M-  ni  a   primary  coil  of  coarse  wire,  with 

a    vibi    '   •  ,        ,  iluni    interrupler.       I  he  dischar.uc   \\hich   is  sent 

1    '    •    i  i    '  ol    I  he  -a  I  ne  ex  l  |-;i  current   l  hat    i-  ut  il  i/.ed  for  li^'ht  - 

L1,:     i'-t-   !••     elect  n'cit  v.      Tin-   is  a   current    of  self-induction   in   the 


GALVANIC,    FAHADIC,    AND    SINUSOIDAL    KI.K<  TROTH  KKAI'Y  4M(.» 

primary  coil.  There  is  no  secondary  coil.  A  battery  of  three  or  four 
wet  or  dry  cells  is  sufficient  for  this  purpose,  or  a  suitable  strength  of 
current  may  be  derived  from  the  direct  electric-light  circuit.  The  ad- 
justment of  the  induced  current  is  twofold:  regulation  of  the  number 
of  turns  utilized  in  the  primary  coil,  and  regulation  of  the  position  of  the 
iron  core.  Drawing  the  latter  out  of  the  primary  coil  makes  the  induced 
current  weaker,  and  alters  its  character,  making  it  less  harsh,  just  as  in 
the  case  of  a  faradic  coil. 

Intermittent  Claudication.— A  case  of  this  disease  without  any  per- 
ceptible femoral  pulse  and  long  inability  to  walk  was  cured  by  \V. 
Kuhn.1  The  faradic  current  was  applied  to  both  legs  by  a  four-cell  bath. 

Currents  Employed  in  General  Hydro-electrotherapy. — Galvanic 
and  faradic  currents  are  largely  employed. 


Sinusoidal,   undulatory,  and  triple-phased   currents  are  especially 

effective. 

Undulatory  Current*. — These  are  unidirectional,  and  increase  and 
diminish  in  a  regular  curve  (Fig.  294),  similar  to  portions  of  a  tracing 
made  by  a  sinusoidal  current.  The}'  are  used  in  the  same  periodicity 
and  strength  as  the  sinusoidal  currents,  whose  effects  are  also  very 
similar. 

Sinusoidal  Currents. — The  name  is  derived  from  the  sinusoidal  curve 
formed  by  a  graphic  record  of  the  current.  This  resembles  a  semicircle 
above  the  zero  line  continued  in  a  semicircle  below  that  line.  The 
current,  therefore,  is  an  alternating  one  with  a  gradual  change  of  strength 
and  direction.  In  the  Wappler  sinusoidal  apparatus,  one  of  the  types 
employed  by  the  author,  the  direct  110  volts  electric-light  current  is 
reduced  to  a  certain  maximum  limit  by  a  volt  controller  and  a  rheostat, 
which  are  set  stationary  for  each  treatment.  There  is  also  a  rheostat 
in  the  shape  of  a  drum-shaped  spiral  of  wire  and  an  electric  motor  moves 
a  contact  back  and  forth  along  the  drum.  When  the  contact  is  at  one 
extremity  of  the  drum  the  fixed  maximum  current  flows  in  one  direction. 
As  the  contact  moves  along  the  drum  the  strength  of  the  current  gradu- 
ally diminishes  and  at  the  middle  point  is  of  xero  strength,  and  be- 
yond that  point  the  current  begins  to  Mow  in  the  opposite  direction  and 
gradually  attains  the  fixed  maximum  strength.  A  complete  cycle  would 
mean  the  time  elapsing  between  the  maximum  flow  in  one  direction 
and  the  next  maximum  flow  in  the  same  direction.  For  many  purposes 
the  author  sets  the  maximum  current  at  l-l  or  20  or,  possibly,  2.">  milli- 
amperes.  and  each  complete  cycle  occupied  about  live  seconds.  The 
current  is  applied  through  wet  electrodes,  usually  by  means  of  a  four- 
cell  bath,  for  ten  or  fifteen  minutes.  This  may  be  called  a  slow  sinus- 
oidal current . 

Morse's  Surging  Electric  Apparatus.-    The  apparatus-  comprises  a 

1  ZiMitralblatt  f.  riiirur<;ii\  April  I'll.  I'.U:!. 

*  AIIKT.  Jour.  Klortrot  lu-rapy  and  Radiology.  \  <>1.  \\xvi.  No.  1,  January,  I'.Us.  p.  tti. 


(10 


MKDICAL    KLK(  TKK1TY    AM)    UO.NTCKX    HAYS 


-inusi  il.lal  generator  with  2000  alternations  or  1000  impulses  a  minute 
and  means  of  applying  this  current  in,  say,  20  or  2  1  waves  a  minute; 
also  27  sixes  of  pads  for  use  as  electrodes.  The  currents  are  induction 
currents  (»f  small  volume  and  short  duration  like  faradic  currents,  hut  of 
greater  uniformity, 

A.  B.  Ilii'sh  had  the  Morse  apparatus  applied  to  lumselt  and  found 
contractions  detween  the  electrodes  uniform,  rhythmic,  gentle;  no  heat 
or  local  action;  no  other  unpleasant  sensation. 

Treatment  of  Flat-foot  by  Surging  Currents.  Stimulate  the  tihialis 
anticus  by  a  moist  elect  rode  on  the  inner  side  of  the  knee  and  another 
at  the  Untom  and  inside  of  the  affected  area  and  apply  a  suridn<r  elec- 
tric mipuUr  at  t  he  rat  e  ot  about  21  per  nil  nut  e  I  Morse,  see  pa  tie  4^0). 

The  Mel  iitnuli  /><>!  i/s/  ni  1/1  t/i  I'lifn/'.  also  in  use  in  t  he  an  t  hoc' s  office,  em- 
ploy- power  derived  from  t  he  elect  ric-li^ht  current.  F.ither  alternating 
or  direct  current  is  employed  to  run  a  small  dvr.amo  "XMicnU insj  an  alter- 


natmtr  current  of  the  sinusoidal  type  with  a  periodicity  ot  from  12  to 
1  xi  id  cycle-  a  minute.  The  polysine  u'enerator  also  delivers  different 
older  type-  of  current,  includiiiii  the  direct  pdvanic  current. 

I  he  author  find-  the  -low  sinusoidal  current  preferable  lor  a  local 
effect  upon  muscles  and  nerve-  in  paralysis,  spastic  conditions,  and 
neiirit  i-. 

I  he  rapid   -inu-oidal  current    i-  an  exceedingly  valuable  thei'apeutic 

a'_"-nt   iii  heart  di-ea-e.  for  \\hich  it   is  u-ually  applied  as  a  hydro-electric 

I     i  he  i     :    |  ill  I   bat  h    or  a    I  <  iiir-ce||   ba  t  h  ma  \   be  employed  accord- 

•  L   t'i  whether  or  not    thi1  general  effect  of  the  full  hot-water  bath  with 

i>onic  acid  tras  i-  desirable.      The  benefit   in  heart  disease 

lemon   irable    hoi    onl\-    m    relief   from   o])pression,   but    also   in   more 

'     '  .'  raphic   and    elect rocardio^raphic    tracings   and   other 

improved  object     .      ni'iis. 

In  lain    for  hydro-electric  baths  it  isabsolulelyessontinlthnl 

t  here  -hall  be  no  i|'ir<-ct  connection  of  the  pat  ient ,  or  1  he  water  in  which  he 


(i.VLVAXJC,    FARADIC,    AND    SINUSOIDAL    KLKCTKOTUKUAPY  441 

is  placed,  with  the  electric-light  current.  This  would  be  dangerous  in 
case  of  grounding  through  the  water-pipes  and  elsewhere. 

Smith,  of  Marbach  on  the  Bodensee,  is  to  be  credited  with  the  intro- 
duction of  sinusoidal  currents  into  therapeutics. 

Strubel's  "das  \Vechselstrombad"  is  a  mine  of  information,  not  only 
in  regard  to  his  own  use  of  the  sinusoidal  current,  but  of  other  recorded 
observations.  It  is  the  authority  for  many  of  the  following  statements: 

Sinusoidal  currents  applied  to  muscles  and  motor  nerves  produce 
tetanic  contraction,  but  each  curve  being  a  more  gradual  one  requires  a 
much  greater  strength  of  current  than  with  faradisrn. 

The  patient  experiences  a  sense  of  billowy  waves  in  the  whole  mus- 
cular system,  and  these  waves  of  contraction  can  be  noticed  if  the  hand 
is  laid  upon  the  patient. 

There  is  a  regulating  effect  upon  the  blood-pressure,  reducing  it  in 
cases  of  hypertension  and  raising  it  in  low  arterial  tension.  Many 
different  observers  have  corroborated  Hornung's  statement  that  a  re- 
laxed dilated  heart  may  be  found  smaller  after  a  sinusoidal  bath.  This  is 
accompanied  by  increased  cardiac  efficiency  and  a  higher  blood-pressure 
of  a  beneficial  character. 

They  do  not,  like  hydrotherapy,  dilate  the  superficial  blood-vessels 
either  immediately  or  later. 

There  is  no  angiospasm  or  marked  blanching  of  the  surface,  such  as 
occurs  in  a  cold  carbonic  acid  bath. 

Lippert  classifies  the  principal  effects  of  sinusoidal  currents  as: 

1.  Generally  raising  the  blood-pressure  and  slowing  the  pulse. 

2.  Decided  increase  in  metabolism. 

3.  Exercise  of  the  heart  muscle  and  of  the  general  muscular  system. 

4.  Assisting  the  patient  to  sleep. 

In  a  full  bath  it  is  estimated  by  Eulenburg  that  one-fourth  to  one- 
third  of  the  current  passes  through  the  body.  It  all  passes  through  the 
patient  in  a  four-cell  bath. 

Arteriosclerosis  is  usually  a  centra-indication  to  the  use  of  sinusoidal 
currents. 

An  extremely  feeble  heart  is  a  centra-indication  and  so  is  coronary 
endarteritis. 

Sinusoidal  currents  are  especially  indicated  in  uncomplicated  insuffi- 
ciency of  the  heart  muscle,  also  even  in  the  most  severe  cases  follow- 
ing infectious,  toxic  conditions  and  overwork,  heart  disease,  with  com- 
mencing failure  of  compensation,  chronic  myocarditis,  cardiac  and 
vascular  neuroses.  According  to  Hornung,  the  faradic  current  is  to  be 
preferred  in  treating  excitable  patients  with  malnutrition,  weakness,  and 
anemia. 

Hypertrophy  of  the  left  ventricle  is  generally  not  reduced,  but  irregu- 
lar and  rapid  pulse  and  cardiac  murmurs  are  greatly  improved  as  well  as 
all  the  subjective  symptoms. 

The  four-cell  bath,  with  a  sinusoidal  current  of  20  to  30  ma.  in  the 
hands  of  Lossen,  has  given  good  results  in  neurasthenia,  improving  the 
feeling  of  apprehension,  palpitation,  appetite,  digestion,  sleep,  and  motor 
power.  Excellent  results  were  had  in  arthritis  deformans.  arthritis 
urica,  chorea,  muscular  rheumatism,  cerebral  and  peripheral  paralyses, 
neuralgias,  cramps,  anesthesia,  and  paresthesias.  The  present  author 
corroborates  this  from  his  own  experience.  Lossen  secured  improvement 
in  locomotor  ataxia,  especially  in  the  lightning  pains,  the  disturbances 


142  MKDICAL    KI.KtTUK  ITY    A.\I>    RONTGEN*    HAYS 

of  >en>ation,  and  to  .-ome  extent  in  the  ataxic  gait.  Lossen  corroborates 
Yon  Noorden's  observation  of  cases  of  diabetes  in  which  the  muscular 
pains  and  weakne--.  eczema,  and  insomnia  were  benefited. 

The  current  fora  full  bath  should  always  be  gradually  increased  from 
/ero  to  about  30  ma.  and  as  gradually  reduced  at  the  end  of  the  treatment. 
The  electrode-  had  better  all  be  the  same  size,  .10  by  2.1  cm.  (20  by  10 
indie-  .  and  if  a  triple  pha.-e  current  is  used  the  electrodes  are  near  the 
nape  of  the  neck,  the  feet,  and  the  pelvis.  Baedeker  recommends  that 
the  temperature  of  the  water  shall  be  U()°  F..  and  that  first  treatment 
of  -ix  or  eiu'ht  minute-,  during  which  time  a  cool  wet  towel  shall  be  laid 
on  the  patient'-  head,  and  that  the  current  shall  be  followed  by  general 
ma— aue  or  vibration.  Baedeker  has  often  noticed  a  temporary  heart 
murmur  after  the  treatment  which  was  not  audible  before.  The  symp- 
tom- of  valvular  -tenosis.  asthmatic  attacks  and  edema,  and  general 
mu-cular  weakne—  are  improved.  Slight  forms  of  aneurysm  are  bene- 
fited, severe  forms  are  a  coin ra-indication.  High  degrees  of  disturbance 
of  compensation  are  a  centra-indication. 

Strubel's  technic  is  to  place  the  patient  in  a  warm  water  bath  of 
(.i.l  or  H7  F.  without  an  electric  current,  and  in  two  to  five  minutes  there 
i-  u-ually  a  reduction  of  20  or  30  mm.  in  blood-pressure  from  peripheral 
vasodilatation.  Then  a  current  of  10  or  20  or.  at  the  most,  30  ma.  is 
cautiou>ly  turned  on.  Now  the  arterial  tension  is  seen  to  rise,  the 
pre— ure  in  the  auricles  falls.  This  lessens  the  dyspnea  of  certain  slight 
cardiac  cases.  Increasing  the  current  to  2.1  or  30  ma.  raises  the  blood- 
piv— ure  to  it-  original  point.  Oradually  turning  off  the  current  causes 
a  reduction  in  the  blood-pressure,  and  in  most  cases  it  remains  below  the 
ordinary  level  for  one-half  to  one  hour.  Strubel's  work  with  hundreds 
of  cardiac  cases  -howed  improvement  in  the  electrocardiograph  as  well 
as  in  the  ordinary  objective  and  subjective  symptoms.  He  considers 
the  indication.-  for  sinusoidal  current  baths  to  be:  (1)  Neurasthenia, 
hysteria,  hypochondria -is,  and  exhaust  ive  conditions;  (  2  )  myocarditis:  (3) 
valvular  le-ion- ;  1  exophthalmic  goiter  and  other  thyroid  intoxications. 
It  doe-  not  reduce  i  he  -ize  of  t  he  t  hyroid  gland,  t  he  possibility  of  toxemia, 
or  of  emaciation,  but  it  doe-  improve  the  pulse-rate,  the  insomnia,  and 
ct  rocardiogram :  -1  .-elected  cases  of  arteriosclerosis,  characterized 
by  the  subjective  symptoms  of  angina  pedori-.  cardiac  asthma,  mild  or 
severe  dy-pnea .  and  1  he  objective  sympt  oms  of  increasing  cardiac  insuffi- 
ciency, arrhythmia,  marked  change-  in  the  form  of  the  heart,  and  in  the 
electrocardiogram.  In  such  cases  strophanthus,  Marienbad  water  to 
drink,  ma— a<j;e,  and  -inusoidal  currents  are  wonderfully  beneficial;  (0) 
organic  nerve  di-ea-es. 

I.aquer  advise-  beginning  the  treatment  of  a  neurasthenic  patient, 
cardiac  -vmptom-.  at  fir-t  with  hydrot  herapv  and  later 
to  cautiou-lv  apply  -inusoidal  current-. 

Physiologic  Effects  of  General  Hydrogalvanic  Baths.—  The  patient 
lh  a  longitudinal  electrode  near  the  whole  length  of  the 
l  In  occiput  to  the  lumbar  region,  and  with  the  other 
I  from  . >0  to  ].)()  ma.  is  generally 
arts  of  plain  water.  According 
ent .  of  t  he  current  will  1  raverse 
<  >f  bat  h-  and  elect  rode-  and  dif- 
per  cent .  for  a  bipolar  bath  to 
ntilv  one 


GALVANIC,     FARADIC,     AND    SINTSOIDAL    KLK<  TIK  )TI  FKUAI'V  443 

electrode,  and  the  entire  current  (Biters  the  body.  The  nervous  struc- 
tures form  the  principal  conducting  paths  for  the  current  after  it  has 
oassed  through  the  skin. 

Effects  rcyantlcx*  of  polariti/  are  a  sensation  of  warmth  and  a  red- 
ness of  the  skin,  especially  near  the  electrode,  but  also  more  or  less 
general. 

Effects  with  the  negative  dorxtil  electrode  and  the  positive  electrode 
near  the  feet.  There  is  an  increase  in  general  sensory  and  motor  and 
reflex  excitability,  and  often  annoying  tingling  of  the  skin  of  the  Legs. 
C'erebral  activity  is  stimulated,  and  in  neurotic  persons  there  may  be 
irritability  of  temper  and  insomnia  after  a  few  treatments.  Neuras- 
thenic, hysteric,  or  insane  patients  are  often  unable  to  take  this  treat- 
ment, even  with  the  weakest  currents,  and  sometimes  not  even  with 
the  current  polarity  reversed.  Patients  suffering  from  conditions  of 
depression  experience  a  sense  of  almost  immediate  relief,  and  if  there  has 
been  uncertainty  of  equilibration,  this  is  recovered  from  after  a  few 
treatments.  The  pulse-rate  is  increased,  especially  if  there  has  been 
bradycardia.  There  are  increased  amplitude  of  the  pulse  and  increased 
arterial  tension,  especially  in  cases  with  hypotension.  There  are  in- 
creased cerebral  and  sexual  activity.  Asthenopia  and  other  functional 
disturbances  of  the  cranial  nerves  are  benefited. 

Patients  with  weakness  of  the  cardiac  muscle  from  fatty  degenera- 
tion or  produced  by  valvular  disease  show  immediate  benefit  after  such 
a  hydrogalvanic  bath. 

Multiple  neuritis  is  certainly  benefited,  and  so  are  anterior  polio- 
myelitis and  post-diphtheric  paralysis.  Tin1  arthritic  diathesis  is  bene- 
fited, and  medicinal  substances  are  now  often  added  to  the  water  in 
these  cases. 

Effects  with  the  Positive  Pole  at  the  Nucha  and  the  Negative 
at  the  Feet. — The  differen-e  between  this  and  the  other  polarity  is  in 
the  direction  of  producing  a  sedative  effect  upon  the  nervous  system, 
but  this  is  not  at  all  constant,  and  the  excitability  of  the  brain  and 
medulla  are  not  generally  diminished. 

The  hydrogalvanic  bath  is  used  for  obesity,  but  its  benefit  is  not  yet 
fully  established.  The  treatment  acts  in  this  disease  and  in  the  arthritic 
diathesis  by  the  production  of  nascent  oxygen,  and  an  increase  in  oxida- 
tion and  all  other  tissue  exchanges. 

Galvanic  Hydro-electric  Baths  in  Sciatica. — This  method  of 
applying  galvanic  currents  results  in  the  cure1  of  a  large  majority  ot  the 
cases. 

Hydro-electric  Baths  in  the  Lightning  Pains  of  Locomotor 
Ataxia.— Balsumoff1  secured  relief  in  these  cases  by  general  galvanic 
baths,  followed  each  time  by  an  application  with  the  current  localized 
in  the  painful  region. 

Cell-baths  and  Their  Effect  with  Galvanic  Currents. --These  are  a 
specific  for  locali/ed  neuritis:  the  same  strength  or  a  greater  strength 
of  current  may  be  used  as  it'  the  electrode  were  not  formed  ot  a  mass 
of  liquid.  The  author's  plan  of  having  the  patient  wear  a  stocking  or  a 
gauxe  bandage  prevents  an  irritation  at  ihe  upper  surface  of  the  liquid 
an  effect  of  oxidation.  Adding  glycerin  to  the  water  has  the  same 
effect. 

The  addition  of  a  medicinal  substance  enables  one  to  secure  a  cata- 
1  First  Intermit.  Coim.  <>t'  1'hysini  hrrapy.  Licjre,  190.">. 


MKDICAL    KI.F.l  TKK Tl'V    AM)    K»  )\T(i  KN"    KAYS 

phnretic  effect.  Schnee's  four-cell  l>ath  i  Fiji's.  2<M>  Mini  297")  or  general 
ualvanic  l>ath>  >iirc;>f(l  in  the  pains  of  locomotor  ataxia,  swcllinjj;  of  the 
U'U>.  -riatic  nruraluia.  chi'onic  muscular  or  articular  rliruniat ism. 


In  inveterate  chronic  articular  rheumatism  each  galvanic  hath  may 
follou'ed  liy  I'aradi/ation  of  the  spine. 
1  he   modification  >ho\vn   in    Fiu\  20S   forms  an  excellent   means  of 


Ill'1  i-iiiTi'H  I  -  wilh  -;i  fel  v  ;i  IK  1 


-i'(-:i'   many  difterent   nerve  and  joint  ai'fect ions  ; 


(JALVANIC,     FAKADIC,     AND    SINUSOIDAL    KLKOTROTHKKAPY 


445 


xoidaj  four-cell  haffi  has  a  local  effect  which  may  he  very 
in  I  he  treatment  of  Haynaud's  disease.  Here  the  four-cell 
hath  is  excellent,  acting  by  local  vasodilatation.  The  current  is  an  al- 
ternating one.  and  consequently  hoth  poles  produce  tin;  same  effect. 
(Vll-haths.  whether  galvanic  oi1  otherwise,  have  less  effect  upon  cardiac 
rhythm  and  arterial  tension  than  a  ,u'eneial  hath  with  the  same  kind  of 
current  . 

(  '<  ll-hothx  inth  (ialranic  Currents  in  Ncnritixand  Muscular  Alroph'/ 
of  Traumatic  Origin.—  The  arm  or  the  leu1  is  in  a  negative  hath,  while 


the  positive1  electrode  is  applied  between  the  shoulders.      A  current  of  12 
or  1.)  ma.  may  he  applied  tor  fifteen  or  twenty  minutes  ('very  dav. 

Hydro-electric  Baths  with  Sinusoidal  Currents.— Sinusoidal 
currents  with  a  tension  of  about  .'•>()  volts,  wliich  have  recently  come 
into  such  prominence,  are  <renerally  applied  in  this  way,  and  with 
:i  I'ate  of  about  twenty  periods  a  second.  As  a  general  bath,  these 
-urrents  produce  a  marked  effect  upon  cardiac  action  and  hlood-pres- 
<ure,  and  have1  an  important  field  in  the  treatment  of  cardiovascular 
lisorders. 


Hit  MKDICAL    KLKCrUHTrV    AND     KOXTCIEN     KAYS 

Hydro-elect  ric  baths  with  a  sinusoidal  current  have  an  excellent 
effect  in  heart  disease,  including  cardiac  dilatation. 

For  iniprovenicnt  evidenced  1  >y  the  electrocardiograph  in  arterio- 
sclerosis and  organic  and  t'unct  ional  cardiovascular  diseases  set'  page  320. 
Kaab  advises  the  use  of  a  higher  rate  of  alternation — 14,000  instead 
of  ~>000  per  minute  in  order  to  avoid  pruritus  from  sinusoidal  hydro- 
eli  ctric  bath-.  He  also  think-  it  a  mistake  to  treat  cardiac  cases  from 
the  -tart  with  sinusoidal  currents  exclusively.  'Their  tension  is  o()  volts, 
and  in  -ome  cases  the  faradic  current  with  a  tension  of  only  8  volts  is 
preferable. 

Lippeir  has  made  140  observations  regarding  these  effects,  and 
found  that  I  here  is  an  increase  in  blood-pressure.  It  may  be  10  or  lo 
•  .-•..  more  after  the  bath  than  before.  This  may  be  accompanied  by  a 
reduced  pulse-rate.  There  is  a  pronounced  increase  in  tissue  exchanges. 
Weakened  and  atrophic.  cardiac,  and  other  muscles  are  strengthened. 
Arteriosclerotic  and  neurasthenic  patients  who  have  suffered  from  in- 
»  >\  .ma  are  eiiableil  to  sleep. 

These  (Mil-rent-  have  a  general  tonic  effect  upon  the  tissues. 
They  are  excellent   in  dermatoses  dependent   upon  deficient  tissue 
exchanges,  such  as  inveterate  pruriginous  eczema  and  urticaria. 

They  are  excellent  in  cases  of  paralysis  of  peripheral  nerves,  of  con- 
ble  muscular  atrophy,  and  of  progressive  muscular  atrophy  and 
•:  r  ci  mdit  ii  ins. 

They  are  very  soothing  in  cases  of  neuralgia  and  of  muscular  or 
;  :  '  icular  pain. 

Their  effect    in  n  nal  colic  is  excellent,  and  decided  diuresis  is  pro- 
:ed. 

The  effect  of  hydro-electric  baths  with  sinusoidal  currents  in  cardio- 

va-cular  disease  is  decidedly   different   from   that   of  triphase  currents 

•d    in   the  same   \vav.      Albert    \Yeill   and  M.   Mougeot*   have;   made 

ai'eful   observations    in   a    number  of  cases,     The   temperature  of   the 

nth  was  M  TJ  to  :-!."r  ('..  and  the  patient  remained  in  it  for  ten  minutes 

•fore  the  currents  were  applied.      Measurements  were  made  of  thear- 

1    and    capillary   pressure   before   and    after   the  simple   immersion, 

fter  every  five  minutes  of  application  of  the  sinusoidal  currents. 

1    .•    cardiac  area  was  registered  by  the  oil  hodiograph  before  and  after 

tii'1  treatment.      'I  he  radial  pulse  and  the  capillary  pulse  were  recorded 

mi   a    revolving  cylinder  at    first    in   the  simple  bath,   and  again  after 

•  :.' ;.    M  imiies  o!  sinusoi(lal  currents.      The  electrodes  were  immersed 

'he  outer  surface  of  the  thiidi.  the  left   side  of  the  back,  and  the 

.  • . '   -idf  o]   t  he  f  n  nit  of  t  he  body. 

111-;!'    re.-ults    showed    a    marked    increase    in    arterial    tension,    just 

mi   the  effect   of  baths  with  triple-phase  currents:  little 

1  '.   capillary    pressure;   a   change   in    the   arterial   pulse   in- 

•  ral    resistance   was   not    reduced,  but    was  even  in- 

\vas  dicrotic.  thi-  characteristic  was  diminished. 

ri     '   -   increased   in  size.      A  dilated  hvposvstolic 

i  in  -i/.e.  but   tin-  change  is  much  less  certain  than 

•  fit-,  which  reduce  peripheral  re-ist  aiice. 

fo  thera|)eutic  irnlicai  ions  i-  that    lu'dro-elect  ric 


GALVANIC,     FAKADIC,    AND    SINUSOIDAL    ELK(  THOTHKRAPV  447 

baths  \vitli  sinusoidal  currents  arc  useful  in  functional  hypotension, 
or  when  it  is  present  without  cardiac  lesions;  also  in  mitral  disease, 
when  the  cardiac  muscle  is  still  intact.  If  there  is  such  a  tiling  as  pro- 
ducing a  tonic  effect  upon  the  heart  by  a  peripheral  vasoconstrict ion, 
this  is  what  the  bath  with  a  sinusoidal  current  does.  This  action  would 
be  contraindicated  in  uncompensatcd  dilatation  of  the  heart  and  in  a 
variety  of  cardiovascular  conditions,  where  the  indication  is  to  reduce 
the  blood-pressure  and  the  labor  imposed  upon  the  heart. 

Margaret  (/leaves  has  found  that  hydro-electric  baths  with  sinu- 
soidal currents  give  remarkable  results  in  neuro-arthritic  and  cardio- 
vascular diseases. 

Kellogg  has  also  demonstrated  the  same  excellent  results  from  baths 
with  sinusoidal  currents. 

('cll-bnth.^  irith  Xi'nttxdidal  Currrnt*.— -These  have  an  important 
application  in  gynecology,  as  sitz-baths. 

Hydro-electric  sitz-baths  with  a  sinusoidal  current  of  2400  to 
oOOO  periods  a  minute  have  an  excellent  effect  upon  menorrhagia  due  to 
fibroma,  and  also  upon  eoccygodynia  and  hemorrhoids.  Paull1  has 
obtained  subjective  improvement  without  much  objective  change  in 
suppuration  of  the  adnexa  and  rctroflcxion  of  the  uterus.  The  sitz- 
baths  contain  three1  electrodes — one  in  front,  one  behind,  and  one  at  the 
side,  so  that  the  current  may  be  directed  through  the  pelvis  in  different 
ways. 

Sinusoidal  cell  baths  are  useful  in  all  conditions  for  which  a  general 
sinusoidal  bath  is  used  if  the  condition  is  confined  to  one  limb.  Neu- 
ralgia, rheumatism,  and  gout  are  examples. 

Hydro-electric  Baths  with  Triple-phase  Currents. — The  source 
of  current  is  a  rotary  transformer,  actuated  either  by  the  direct  or  the 
alternating  electric-light  current,  or  by  a  battery  of  accumulators 
(storage-battery).  In  the  latter  case  the  battery  should  generate  12 
volts.  Three  different  wires  leave  the  transformer  at  points  equally 
distant,  and  each  is  traversed  by  an  alternating  current  having  the 
character  called  sinusoidal.  These  currents  are  not  synchronous  in 
the  three  different  wires,  but  have  a  difference  in  time  equal  to  one- 
third  of  a  period.  The  regulation  of  the  currents  is  best  accomplished 


Fi<r.  1>9(). — Sinusoidal  current.  Fit:.  .100.' — I  nple-phase  current. 

if  the  currents  from  the  rotary  transformer  pass  through  the  primary 
wires  of  three  transformers,  in  which  the  secondary  coils  are  at  an  ad- 
justable distance  from  the  primary,  and  consequently  the  induced 
triple-phase  currents  supplied  to  the  three  electrodes  in  the  bath  may 
be  varied  in  strength. 

About  twenty  periods  a  second  is  desirable  for  these  currents,  and 
100  to  140  ma.  is  the  usual  strength  of  current  in  a  general  bath.  The 
same  periodicity,  but  a  much  weaker  current,  is  suitable  for  use  in  a 
cHl-bath  or  for  ordinary  electrodes  with  which  the  full  strength  of  the 
cm-rent  passes  through  the  patient.  In  some  general  baths  with 
medicated  solutions,  on  the  other  hand,  a  much  stronger  current,  such 
1  Zcitschrift  g.  diuet.  u.  physik.  Therapie,  vol.  viii,  November  1,  1905. 


as  HOI)  ma.,  i-  required,  because  a  smaller  fraction  passes  through  the 
patient 's  body. 

The  physiologic  effects  are  to  excite  a  tingling  of  the  skin,  which 
is  extremely  di-agreeable  if  the  periodicity  ot  the  current  is  too  rapid. 
The  triphase  current  -upplieei  by  some  industrial  and  electric-light  cir- 
cuit- has  a  periodicity  of  about  12100  a  minute,  which  is  about  twice  as 
rapid  as  i-  desirable  for  therapeutic  purposes.  A  rotary  transformer 
i-  u-ed  to  change  this  to  a  triphase  current  with  a  periodicity  of  about 
1_M)0  a  minute.  The  more  rapid  periodicities  also  produce  muscular 
contraction  -imilar  to  what  would  occur  from  a  general  application  of  a 
strong  faradic  current,  and  this  also  disqualifies  them  for  therapeutic  use. 

I'ri phase  currents  of  t  he  proper  st  rengt  h  and  periodicity  for  general 

h    ;h-    produce  capillarv   dilatation,    increased    metabolism    in    muscular 

and  oi  her  t  issues,  and  a  red  net  ion  in  blot  id- pressure.      They  are  curative 

in    peripheral     paralysis,     muscular    atrophies,    and     progressive    myo- 

paihies.      Applied  in  moderate  strength  in  cases  of  neuralgia  and  pains 

1     the    muscles    and    joints,    they    are   soothing.      They    have   a   specific 

icia!   effect    upon    the   heart,    relieving  dyspnea,    irregular   rhythm 

and   p;  Ipil  ition,   and    hiuh  arterial  tension.      They  are  especially  bene- 

e    high    arterial    tension    of    uricemia.    the    menopause,    com- 

iiii   arteriosclerosis,   aortic   atheroma.   simple  or  syphilitic.       1  hev 

fail  otilv  in  pronounced  cases  ot  renal  sclerosis. 

\  iei'1  \\eill  and  Mougeot1  find  chang'es  in  the  form  of  the  radial 
pulse  tracing  consisting  in  an  increased  amplitude  of  the  systolic  wave, 
an  increase  or  a  reappearance  of  the  wave  of  arterial  elasticity,  an  in- 
crease- in  dicrot  ism.  I  he\'  find  no  increase'  in  the  amplitude  ot  the 
lary  pulse.  They  find  a  distinct  reduction  in  the  size  of  the  heart 
if  it  has  been  dilated. 

('ill  /;/;'//.-  //•/'///    T/'ijt/i  -/il/nsi   Curr<  •///*.—  These  are  especially  useful 

;n    llayiiaud'-  disease  and  other  local   conditions  of  the  circulatory  dis- 

t  urbaiice,  \\  it  h  capillary  or  arteriole  constriction.      They  are  valuable  in 

•.!;d    in  juint    legions.      They    have  an   important    application  as 

four-cell  baths  m  i  he  treatment  of  rheumatism  and  lithiasis. 

OZONE 

\\heiii  ,'ei  an  elect ric  spark,  whether  powerful  or  almost  impercept- 

-    ihrmiLih   the  air,   ozone   i-   produced   bv   the  action  of  ultra- 

Upoli   i  he  oxygen  of  the  air.      This  very  active  form  of 

•  d  eftects    upon    living  organisms,  and  it  seems  certain 

le  p;  rl    of  ihe  benefit   derived   f  roil  i  the  application  of 

•    or  i!  :LJ  h-i  ri  •<  |in  'tic\    currents  is  due  to  the  absorption  of 

'    t  he  luni!>  or  through  the  skin. 

I'      effects    in    a    concentrated    form    are    poisonous.      Bacteria    are1 

liH-   -uccumb  in   ten   minutes  if  kept    in  an  atmo-- 

-     milligrams    of    <  1/1  me     per    liter.        A     t  herapeiit  ic 

•    •    o-i    I    to  :;  milligrams   per  liter  of  air.  and   a  single' 

ten    minutes    \\ill    increase    the1    proportion    of    oxv- 

-ubiiormal,   and    al>o   I  he   number  of   re-d   blood- 

]"  <••  I'n-ial  effect    from  a  course  of  treatments  is  an 

'.    capacity  and  a   reduction   in  \\hite  blood-cells  if 

':,••. 

1'     i-    indicated 


GALVANIC,    FAKADIC,    AND    SINUSOIDAL    ELECTROTHERAPY 


449 


and  whooping-cough.     It  is  used  also  as  a  general  tonic  in  many  de 
tated  states. 

It  is  to  be  recommended  in  the  strongest  terms  for  use  in  a  work- 
room or  office  where  a  large  number  of  persons  are  employed,  and  where 
it  is  possible  to  secure  good  ventilation,  but  no  sunlight.  A  desirable 
outfit  may  be  obtained  from  the  General  Electric  Company,  and  if  kept 
in  operation  during  business  hours  makes  a  wonderful  difference  in  the 
health  of  the  employe's. 

Method  of  Use. — The  production  of  ozone  by  sparks  of  perceptible 
size  is  accompanied  by  the  production  of  much  nitric  acid  and  other 
substances  which  unsuit  the  air  for  inhalation.  It  should,  therefore,  be 
obtained  from  the  silent  discharge  which  takes  place  from  metallic 
points  charged  with  very  high-tension  electricity  and  which  forms  an 
effluve.  An  ordinary  whisk-broom  connected  with  the  terminal  of  an 
Oudin  resonator  and  held  near  the  patient's  face  is  a  simple  and  effective 
means  of  giving  inhalations  of  ozone.  Stronger  inhalations  are  ob- 
tained by  surrounding  the  Oudin  resonator  or  the  Guilleminot  spiral 
by  a  glass  jar  through  which  air  can  be  inhaled  by  the  patient. 

The  ozone  generator,  shown  in  Fig.  301,  has  a  leading-in  wire  to  be 
connected  with  an  Oudin  resonator  yielding  a  high-potential  high-fre- 


Fig.  301. — Ozone  generator  from  high-frequency  current. 

quency  current.  The  vacuum  chamber  thus  charged  is  surrounded  by 
an  outer  glass  held  in  the  patient's  hand  and  separated  from  the  charged 
glass  by  a  space  in  which  innumerable  sparklets  pass  through  the  air 
with  violet  and  ultraviolet  rays.  This  changes  a  considerable  portion 
of  the  enclosed  air  into  ozone.  The  ozonized  air  is  forced  through  this 
space  and  then  bubbles  through  pineneedle  oil,  or  some  similar  liquid,  to 
absorb  the  nitrogen  pentoxid  before  it  is  inhaled  by  the  patient. 

The  arrangement  used  by  Albert  Weill  for  ozone  inhalations  from  a 
static  machine  is  shown   in   Fig.   302.     The  discharging  rods  of  the 
static  machine  are  within  a  dis- 
tance of  an  inch  or  two,  so  that  a 
stream  of  powerful  sparks  passes 
between  them.     The  outer  coat- 
ing of  a  Leyden  jar  whose  inner 
armature  is  connected  with  the 
positive1  pole  is  grounded.    From 
the   outer   coat    of   the   negative 
Leyden  jar  a  wire  leads  to  an  in- 
sulated  metal   rod   which   enters 
the  ozonizing  bulb,  but  does  not 
touch    its   glass   walls.      A    large 
part  of  the  outside  of  the  ozon- 
izing bulb  is  coated  with  metal,  and  from  this  a  wire  passes  to  the 
earth.     Air  is  driven  through  the  ozonizing  bulb  and  inhaled  by  the 
patient.     A  brush-discharge  occurs  between  the  metal  rod  and  the  glass 


Fig.    302.— Dias 


-l.">0  MEDICAL    ELECTRICITY    AND    KONTCEN    KAYS 

wall  of  the  ozonizing  bulb,  whicli  fills  the  bulb  with  violet  and  ultra- 
violet liirht,  the  latter  causing  a  profuse  generation  of  ozone. 

Chany1  has  made  valuable  observations  upon  the  influence  of  voltage 

on  t  he  format  ion  of  oxone. 

To  be  perceptible  at  all.  several  thousand  volts  an4  required.  The 
.")0-cycle  alternating  elect ric-liii'ht  current  and  a  larire  Kuhmkorff  coil 
is  a  most  effective  generator.  The  voltage  at  which  oxone  is  per- 
cept ible  is  cliaracterixed  by  eflluve.  At  40  per  cent,  of  this  voltage  the 
discharge  is  like  a  ram  o|  lire.  The  power  of  oxone  production  is  as 
the  square  of  the  difference  in  potential  between  the  armatures  of  the 

(  i/.olll/.lllU'   t  lllie. 


O.SliO 
l.oSO 


li    is  useless  to  <i'o  higher  than  the  last   figure,  because  tli<1  quantity 
xone  then  increases  in  simple  proportion  to  the  ener^v  expended. 
1  ('.   1^.  .lc  I'Aca.l.  <lfs  sciences,  June  L',   1(.)()L'. 


PHYSICAL   RECONSTRUCTION  AFTER  WAR  INJURIES 

Tin-:  examination  and  treatment  of  the  different  cases  requires  prac- 
tically all  the  apparatus  and  technic  described  in  the  present  volume. 
And  in  this  brief  section  arc  described  only  a  few  of  the  special  features. 

Testing  for  Nerve  Injury. — W.  ,}.  Turrell1  has  summarized  this  very 
well:  Kach  faradic  stimulus  lasts  about  ni!0-0-  second,  which  is  long 
enough  to  excite  the  nerve  but  not  the  muscle  (nerve  responds  to  -oVo 
second,  muscle  requires  T(Vo  second  or  more).  A  healthy  muscle  with 
normal  nerve  supply  responds  to  1  or  2  ma.  galvanic.  With  nerve 
injured,  the  muscle  requires  3  or  4  ma.  and  if  untreated  may  later  re- 
quire 7  to  20  ma.,  or  may  become  entirely  fibrosed  and  unresponsive. 

Partial  R.  D.  =  diminished  faradic  and  galvanic  excitability  of 
the  nerve,  diminished  faradic  excitability  of  the  muscle,  with  possible 
+  or  —  galvanic  excitability  of  the  muscle. 

Complete  R.  D.  -=  Complete  inexcitability  of  the  nerve,  complete 
inexcitability  of  the  muscle  and  usually  diminished  galvanic  excitability 
of  muscle  (motor  point  also  displaced  toward  the  tendon  "longitudinal 
reaction")  and  slow  character  of  muscular  contraction.  And  also  "Polar 
Inversion"  (normally  KCC  requires  eight  or  nine  times  less  current 
than  A()(1;  and  this  is  reversed  in  R.  D.,  so  that  then  AOC  >  KCC). 

The  chronaxie  method  is  suited  to  the  physiologic  laboratory,  not 
to  the  bedside,  and  may  take  hours  to  examine1  one  patient. 

The  condenser  discharge  method  takes  longer  than  the  faradic  and 
does  not  give  such  precise  information,  and  has  the  great  disadvantage 
of  stimulating  antagonistic  muscles. 

Larat-  tests  the  muscular  response  by  its  lateral  expansion.  A 
circular  band  or  bracelet,  inexpansible  except  3  cm.  of  elastic  with  a 
rubber  bulb  connected  with  a  Marey's  drum,  surrounds  the  limb.  The 
recording  cylinder  makes  a  revolution  in  twenty  minutes.  The1  muscle 
is  stimulated  by  the  bipolar  method.  Abruptness  of  rise  and  fall  in- 
dicate intact  nerve  supply,  and  gradual  rise1  and  fall  the  reverse. 

Nerve  Testing  at  Time  of  Operation. —  The  field  is  dry;  a  glass 
rod  being  placed  under  the  nerve.  A  metal  probe  electrode  applies  a 
weak  intermittant  faradic  current.  Return  of  faradic  excitability  al- 
ways precedes  return  of  voluntary  power. ;i 

The  Daisy  foot  switch  is  useful  for  nerve  and  muscle  testing  (Massey). 

Electric  Treatment  of  Nerve  Injuries. — The  galvanic  current  is 
used  until  a  response  occurs,  and  later  the  faradic  current  until  full 
faradic  response  is  obtained.  Splints  and  massage  are  often  useful.'* 

The  static  induct o-resonat or  is  used  for  treating  paralyzed  and 
atrophied  muscles  (page  76). 

1  Amcr.  .lour.  Electrotherapy  :iml  Radiology,  vol.  xxxvi,  \o.  .">.  June.  I'.US.  p. 
161. 

-Traitr  I'nitique  d'Klectricitc'  Mrdicalc.  I'.HO. 

;  l!o\v1cY-Bristo\v.  Brit.  Mrd.  Jour..  January  5,  1'Mv 

1  \au<ihton  Dunn,  Amcr.  Jour.  Orthopedic  Suri:.,  April.  191S. 

45] 


4")'2  MKDICAL    KI.KCTHK  1TY    AM)    HOXTCIKN    KAYS 

Treatment  of  the  Wounded  Member.— For  physical  reconstruction 
after  war  injuries  Major  Frank  H.  (iranger1  advises  preliminary  warm- 
inir  by  radiant  heat  or  diathermy;  treatment  by  galvanic,  sinusoidal, 
faradic.  static,  and  high-frequency  currents;  massage  and  mechanical 
vibration,  electric  light  cabinet,  (lalvanic  and  faradic  testing  is  ad- 
visable in  many  cases. 

War  wounds  and  fistulous  tracts  from  firearms,  which  are  irregular, 
with  jaiiued  edges,  and  with  a  tendency  to  diffuse  infiltration;  traumatic 
neuralgia  and  neuritis;  burns  by  gas  and  burning  liquid;  keloid;  cica- 
trices; neiiromuscular  troubles  of  stumps:  frost-bite;  nice-rations;  ulcer- 
ations  of  stumps.  All  the  above  are  disinfected  and  healed  by  high- 
frequency  ellluves.  The  same  application  is  analgesic  in  hyperalgesic 
wounds  caused  by  gas  and  burning  liquid,  shrapnel  splinters,  and  in 
other  diffuse  lesions.  There  is  cicatrization  without  erythema  or  scar 
tissue.  Hipolar  eilluves  are  much  more  powerful  and  are  used  for 
deep  wounds.  Mucous  membranes  are  more  sensitive  and  require  very 
short  apphcat  ions.- 

The  constant  or  galvanic  current  is  a  valuable  reparative  in  war 
injuries,  for  ankylosis  following  joint  injuries  and  to  promote  absorp- 
tion of  fibrous  adhesions.3 

Heliotherapy  (page  GDI),  radiant  heat  and  light  (page  (586),  the 
x-ray  (pages  1179  and  1  !!)()),  and  the  static  wave  current,  the  latter 
for  trench  foot  (page  74),  are  important  measures  described  elsewhere. 

1  Amer.  Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi,  No.  9,  September,  1918, 
p.  i>:«. 

-Joseph  Riviere.  Arner.  Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi,  No. 
1,  January,  19ls.  p.  ±>. 

"  H.  !•'.  Pilrher,  Amor.  Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi,  No.  9, 
September,  191s,  p.  238. 


PHYSIOLOGIC    AND    THERAPEUTIC    EFFECTS    OF   ELEC- 
TROMAGNETS 

So  many  excellent  and  entirely  unbiased  observers  have  tested 
the  matter  with  magnets  of  every  possible  strength  and  without  any 
discoverable  effect,  that  the  author  feels  that  these  instruments  cannot 
at  the  present  time  be  considered  as  being  of  practical  value  in  thera- 
peutics. He  does  not  at  all  wish  to  be  understood  as  thinking  that 
prolonged  exposure  to  a  field  in  which  such  tremendous  energy  is 
operative  is  without  some  effect,  and  perhaps  usually  a  deleterious 
effect,  upon  the  human  system.  But  it  does  not  appear  to  have 


Fi.tr.  .'-SO.'?.-  -Therapeutic  application  of  plectromagnetism. 

an  effect  which  can  be  put  to  practical  use.  The  subjective  symp- 
toms of  a  sensation  of  light  and  a  feeling  of  pleasure  or  repulsion 
according  to  the  polarity  are  liable  to  be  partly  of  suggestive  origin. 
Tt  certainly  produces  no  muscular  or  motor  nerve  effect.  The  bene- 
ficial effects  which  have  sometimes  occurred  in  tic  douloureux,  congen- 
ital myotonia.  and  different  neuroses,  are  apt  to  be  transitory  and  are 
possibly  due  to  suggestion.  Cases  of  facial  neuralgia,  intercostal  neu- 
ralgia, alcoholic  neuralgia,  and  nervous  insomnia  have  sometimes  shown 
very  great  improvement. 

453 


454 


MKDICAL    KLK<  TKICITY    AND    KOXTGKX    HAYS 


Technic.  -The  best  technic  appears  to  consist  in  the  use  of  a  current 
which  is  reversed  about  100  times  a  second,  and  which  is  of  low  voltage 
but  high  amperage. 

Outside  df  the  role  that  they  phiy  in  all  kinds  of  coils,  motors,  and 
other  apparat  us.  elect  romagnets  have  two  distinct  uses  in  medicine.  One 
is  the  extraction  of  steel  and  iron  particles,  especially  when  embedded 
in  t  he  eye,  and  anot  her  is  t  heir  application  for  a  supposed  effect  upon  the 
brain  and  other  parts  of  the  nervous  system. 


Klert  mma^net  for  removing  bits  of  steel  from  the  eye. 

Electromagnets  for  Extracting  Foreign  Bodies  from  the  Eye. — 

'I!,1     electron  a'jnel      !'i'_r.   .'!OI)    has    a  large,    soit-iron    core,    terminating 
:      ul  tn      :,  rh  sometimes  different    iron  tips  are  attached.      There 
i-    a    '!     '  '  '  '    danger    in    employing    tremendously   large    and    powerful 
electromagnet-  ch   are    capable    of   drau'gini;'    a    bit    of    steel    or    iron 

through    the    t:iei|i;i    o!    the   eye   and    producing  irreparable   lacerations. 


ELECTRICITY  IN  DISEASES  OF  THE  NERVOUS  SYSTEM 

THK  general  problems  of  electroneurophysiology  have  been  treated 
elsewhere  in  this  work,  and  the  general  relations  of  electricity  to  ner- 
vous irritability  have  been  touched  upon.  In  limiting,  therefore, 
the  consideration  of  the  use  of  various  forms  of  electric  action  to 
diagnosis  and  to  treatment  of  diseases  of  the  nervous  system,  it  is  with 
the  tacit  understanding  that  the  present  chapter  concerns  itself  with  the 
most  practical  of  issues. 

The  applications  of  electricity  in  the  diagnosis  and  treatment  of 
discuses  of  the  nervous  system  are  increasing  in  number  and  in  value 
every  year;  the  introduction  of  newer  currents  is  constantly  widening 
the  field,  and  with  each  new  installment  of  scientific  journals,  new 
processes  arc  described  which  often  find  a  permanent  place  in  nervous 
therapeutics.  The  following  pages  have  been  prepared  to  present 
the  present-day  aspect  of  what  has  been  demonstrated  to  be  of  per- 
manent value,  as  well  as  to  endeavor  to  point  out  the  merits  of  some  of 
the  more  important  of  the  later  advances  in  the  science  of  electro- 
therapeutics as  applied  to  the  disorders  of  the  nervous  system. 

The  topics  to  be  discussed  will  be  as  follows: 

(I)  The  use  of  electricity  in  diagnosis. 

(a)   Diagnosis  of  disorders  of  peripheral  nervous  systems — .motor 

and  sensory. 
(!>')    Diagnosis  of  disorders  of  central  nervous  systems. 

(II)  The  use  of  electricity  in  therapeutics. 

(a)   Therapeutic    applications    of    electricity    in    diseases    of    the 
peripheral  nervous  system. 

(/>)   Therapeutic  applications  of  electricity  in  diseases  of  the  neuro- 
muscular  apparatus    -neuromuscular  disorders. 
Therapeutic  applications  of  electricity  in  treatment  of  organic 
disease  of  the  central  nervous  system. 

Therapeutic  applications  of  electricity  in  treatment  of  func- 
tional diseases  of  the  central  nervous  system. 

(III)  Klcctric  sleep  and  death  due  to  elect  lie  currents. 

DIAGNOSIS   OF  DISORDERS   OF  THE  PERIPHERAL  NERVOUS  SYSTEM 

Motor  Reactions.  —The  principles  of  nerve  stimulation  and  mu>de 
reaction  have  been  considered  elsewhere  at  great  length.  There  remain^ 
here  to  take  up  the  specific  applications  of  such  teachings,  particular- 
izing on  the  subject  of  the  reactions  of  the  neuromuscular  apparatus  for 
diagnostic  purposes. 

It  is  to  be  recalled  that  when  a  galvanic  current  of  sufficient  strength 
is  passed  through  a  neuromuscular  arc,  it  causes  a  contraction  in  the 
muscular  portion  of  the  arc,  or  in  the  particular  muscle  if  the  arc  in- 
cludes but  one  muscle.  This  contraction,  as  has  already  been  seen, 
is  not  for  the  galvanic  current  a  continuous  reaction.  It  takes  place 
only  when  — 

toy 


MKDICAI.    KI.KeTKlelTY    AM)    KnNTOKN    HAYS 


(  M 

Tie  current  stops.  /'.  i .,  at  current  opening. 
'here  i-  a  sudden  increase  in  force  of  current. 
/here  is  a  marked  decrease  in  strength  of  current. 
'he    direction    of    the   current    is    reversed,    anode    to    cathode; 
ide  to  am  "  le. 

Kxperimentat  ion  on  lower  animals  has  permitted  the  laying  down 
of  certain  la\vs  re-'ulat  im:  the  actions  of  the  galvanic  current — i.  e., 
I'thiiivr's  laws,  which  have  been  discussed  elsewhere  in  this  volume. 
The-e  laws  have  a  limited  application  in  human  neuro-electric  technics. 
The  laws  of  human  normal  muscle  contraction  then  are  for  an  intact 
nervous  or-ani/.ation  to  be  expressed  as  follows  for  weak,  medium,  and 
strong  current  s. 

I.   ('('1C.  for  weak  currents  fcathodal  closure  contraction  only). 
II.  ('('1C,  AC1C.  A<  >C.  in  order  of  activity  for  medium  currents. 
III.  CCH'et,  AC1C.  AOC.  CC1C,  for  strong  currents  (cathodal  closure 
tetanus,  aliodal  closure  contraction,  etc.). 

'["he  strength  of  such  currents  has  been  accurately  measured  by 
Simi/iiii:  and  Krb  and  a  number  of  students.  Stintzing  has  examined 
most  of  the  muscles  of  the  body,  to  determine  the  minimum  amount  of 
current  that  will  cause  a  cathodal  closure  contraction,  and  has  con- 
structed table-  which  give  the  average  values  in  the  different  muscles 
and  nerves  of  the  body.  These  tables  are  of  great  value  for  compara- 
tive purposes  his  faradic  tables  are  of  little  practical  value  for  the 
average  practitioner:  his  galvanic  tables,  however,  are  useful,  and  are 
here  printed.  It  must  be  remembered  that  great  variation  exist-  in 
different  nerve-trunks  to  the  same  strength  of  galvanic  current.  Such 
variation  exists  for  differing  ages,  and  have  been  made  the  subject  of 
special  researches  of  a  very  intricate  and  extensive  nature  by  numerous 
experimenters  Mann.1  Westphal.  Thienisch.  and  others. 

XKCROMCSCCLAR 


INTZING'S    TAHLE    FOR    GALVANIC    S( 

'ALE    OF     NEf 

i:.\'  ITAI'-ILITV    IX    MILL 

[AMPERES. 

I.  <  JUKI;  LIMIT 

UPPKH  LIMIT 

VAI.I-E. 

VALVE. 

Ma. 

Ma. 

1      M'.l-r"ilni"  ;i;i!i.  •'.!!-                                   O.O.") 

0.2S 

.0.10 

0.44 

0.20 

O.'.tO 

!.    !'•  •    •  •                                                       0.20 

2.00 

'•     '    '                                                                       0.  10 

i  'TO 

7.     I  if.                                                                (I.  Id 

2,")0 

V       M>    •    '                                                                                                    [)..")() 

1.40 

'  '        1       '        •                                                                                          1  M  ,1 
i       '/  •     •                                                                                             i  \   ^.i 

2.r>o 

1  1    t  \l  \ 

II   '.II 

2.00 

2  HI) 

i    HI 

2.70 

!  in 

2  .")(  1 

Method  < >{  Study  for  Disease  of  Neuromuscular  Apparatus 

e  MI    i'-    motor  nerve  or  'he  end-plates  become 
tune!  i(,n<,   certain   ('lectric   changes  are  apt    to  take 
'h  their  (jiiant  itat  i\-e  and  (jualit  at  i\'e  reaction 
'    .  -pecial  i  \" j >^~-  oi  curi'ent  s. 
•:  i-lcftrii  itc  in<'ilic:tlf     \'.<^'-'>,  f 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  4o7 

The  qualitative  changes,  which  are  the  more  readily  observed,  con- 
sist in  a  change  in  the  formula  of  contraction,  or  a  modification  in  some 
particular  of  the  normal  formula. 

Such  variations  may  depend  upon  purely  accidental  modifications 
of  contact,  of  saturation  of  electrodes,  etc.,  but  assuming  the  teehnic 
to  be  five  from  graver  errors,  these  changes  are  dependent  in  large 
part  on  the  more  or  less  superficial  seat  of  the  nerve-fibers.  Diffusion 
produces  a  certain  amount  of  scattering  for  the  deeper  seated  nerve- 
fibers,  and  thus  only  a  part  of  the  current  registered  by  the  galvan- 
ometer is  utilized.  Fat  makes  considerable  variation,  and,  as  has 
been  noted,  the  age  of  the  patient  is  of  moment.  This  latter  fact  is  of 
importance  in  determining  the  Krb  reaction  in  children  thought  to  be 
suffering  from  tetany,  since  very  frequently  much  heavier  currents  are 
needed  in  infants  and  children. 

Further  modifications  depend  largely  upon  the  rate  of  make  and 
break  in  an  interrupted  (faradic)  current.  Tetanus  usually  results 
if  the  interruptions  are  over  twenty  a  second.  The  introduction  of 
the  induction-coil,  however,  has  caused  a  number  of  complications  in 
the  tests  usually  applied,  since  the  discharges  are  usually  irregular  as 
to  quantity  and  as  to  duration,  and  d'Arsonval  has  shown  the  great 
importance  that  is  to  be  attached  to  the  form  of  the  wave  of  the  electric 
impulse.  This  has  led  to  the  introduction  of  mechanic  forms  of  making 
and  breaking  by  Leduc,  since  a  greater  amount  of  regularity  in  making 
and  breaking  results  than  when  the  induction-coil  is  employed.  They 
are  further  capable  of  more  accurate  mensuration.  Leduc  has  shown 
that  when  the  impulses  have  only  a  duration  of  about  y^1,,^  second, 
and  follow  each  other  at  the  rate  of  100  to  the  second,  the  best  type  of 
effect  is  produced.  Thus  Leduc's  table  is  of  interest  in  this  connection:1 

DCKATION   OF  E.    M.    F.    UKqriKKI)   TO  PuODTCE 

IMITLSE.  Mrsrn.AK  CONTRACTION. 

SKCONDS.  VOLTS. 

0.00001  22.0 

0.00010  15.0 

0.00020  13.5 

0.00030  12.0 

0.00040  1 1  .5 

0.00050  10.5 

0.00060  9.5 

0.00070                      .  9.0 

0.00090  S.5 

0.00100  7.0 

0.00200  7.5 

0.00300  S.O 

0.00100  S.5 

0.00500  9.0 

0.00(100  9.5 

0.00700  10.0 

0.00X00  11.0 

0.00900  12.0 

The  important  advance  that  lias  come  about  by  the  introduction  of 
Leduc V  apparatus  is  that  the  amount  of  degeneration  in  the  neuro- 
muscular  apparatus  is  subject  to  more  accurate  mensuration  (see  p. 
494).  Heretofore  we  have  had  to  depend  on  the  crude1  expression 
that  R.  I),  is  present.  By  means  of  the  Leduc  apparatus  an  estima- 

1  Arch.  iI'Elec.  Mrd..  September  15,  1903. 


458 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


tion  of  the  extent  of  disease  in  the  neuromuscuiar  mechanism  may  be 

secured. 

In  testing  the  muscular  apparatus,  a  knowledge  of  the  motor  points 
is  desirable  if  the  reaction  of  the  adjacent  or  subjacent  muscles  is  to 
be  determined.  Such  points  represent  the  sites  at  which  maximum 
etYect.-  may  be  obtained  with  minimum  currents.  These  arc  usually 
the  points  of  direct  ingress  of  the  motor  nerve  into  the  muscle  mass.  In 
the  ca>e  of  superficial  muscles,  particularly  in  lean  individuals,  they 
are  sharply  delimited:  but  in  fat  subjects,  and  for  deeper  muscles,  dif- 
fusion tends  to  confuse  the  picture,  often  very  material!}'.  They  are 
illustrated  in  IMates  1  >s. 


1         '  •    •  •  t    1,-.   L';il\  :mir  or  far.-iilic  or  rli\  t  lunic  currents.       A  smitllrr  :ict  ivc  clcr- 


Modes  of  Testing.     Tin1  horizontal  position  is  uenerallv  advisable 

!'•   relaxation  as  pos.-ible.      In  some  p.-itients  the   sitting 

p"-  i'i|Uall\     convenient.       The    indifferent     electrode,    preferably 

;  '  »"<  iii'jhlv  moistened    and    placetl    upon  t  he  spine,  eit  her 

-    Up|"  '     01     lower    part.    >  le]  ie;it  lni^    larjielv    Upon    the    region    to    be 

-    e;«  d  1 1  ulc   >hou!d  be  applied    firmK'  to   the   skin,  and    held 

.'     :      '•'    '    '  '.  <  I'jht  rif  the  lind\-.  the  hand,  or  a  banda.ire.     The 

e\ ;  'In;  •:!,:•    <''<••  •'.<!..  prnx^ided  with  make  and  break  mechanism,  is  then 

points,    and    a    systematic    examination   carried 

••'       '         '  '  ill    '  lie    need.-    nt    t  he    pat  lent     ll''i'_r.    .''JO")). 

le  tuethod   i-  that   emjiloyed  b\    the  author,  and, 
a.-  h>    knov,    .   .     oriLrmal   \\  i\\\  him. 


ELECTRICITY    IN    D1SKASKS    OK   THE    NEUVOl'S    SYSTEM 


459 


The  indifferent  electrode;  is  preferably  made;  of  block  tin  -3'3  inch 
thick,  and  '2  by  3  inches  in  area.  For  this  I  have  slip-covers  made  of 
absorbent  felt. 

The  part  of  the  body  on  which  the  indifferent  electrode  is  to  be 
placed  should  be  thoroughly  washed,  using  tincture  of  green  soap. 
The  slip-cover  is  thoroughly  wet  in  a  solution  of  bicarbonate  of  soda, 
consisting  of  1  dram  of  bicarbonate  to  4  ounces  of  water. 

The  exploring  electrode,  as  shown  at  13,  Fig.  300,  consists  of  a 
circular  disk  made1  of  pure;  block  tin,  and  having  a  groove  around  it  so 
that  it  can  be  easily  covered  with  a  piece  of  chamois.  This  chamois 
is  to  be  thoroughly  wet  in  the  bicarbonate  of  soda  solution.  The  area 
to  be  explored  should  be  thoroughly  cleaned,  using  the  usual  green  soap 
tincture.  This  is  to  remove  any  fatty  material  which  would  offer  a 
high  resistance. 

In  place  of  the  usual  interrupting  handle,  Fi»-.  300,  C,  I  use  a  combi- 
nation electrode.  B  is  screwed  into  the  handle,  K.  Inside  of  this 
handle  is  a  compression  spring.  The  central  metal  rod  F  has  the  upper 


SIP 


Hard  rubber  Graduated  in  pound- 

I  Metal 


Metal 


Fij;.  'iUO. — Author's  exploring  electrode  with  standard  pressure. 

part  graduated,  so  as  to  indicate  the  amount  of  pressure  with  which 
the  electrode  B  is  held  in  contact  with  the  skin.  As  a  rule,  using  an 
electrode  '.  inch  in  diameter,  a  pressure  of  1',  pounds  is  sufficient. 

In  circuit  with  this  holder  is  placed  a  separate  interrupting  handle 
shown  by  Fig.  300,  1).  This  is  held  in  the  left  hand  of  the  operator,  so 
that  as  the  exploring  electrode  is  moved  from  one  place  to  another,  the 
pressure  used  to  make  and  break  the  circuit  in  I)  will  not  affect  the 
contact  pressure  between  the  electrode  and  the  patient.  This  is  a  most 
important  point,  as  the  resistance  will  vary  according  to  the  pressure. 
This  is  more  particularly  so  when  a  sponge  electrode  is  used  in  place  of 
the  chamois-covered  metal  electrode  above  described. 

Investigators  with  lartre  experience  advise  the  beginning  of  an 
examination  by  means  of  the  faradic  cm-rent.  In  this  manner  it  is  held 
that  polarization  is  prevented.  Furthermore,  if  no  alteration  in  fa- 
radic excitability  is  obtained  by  minimum  currents,  it  usually  toll<>w> 
that  there  are  few  changes  to  the  galvanic  current.  In  beginning  the 


-ItiO  MK.ru  AI.   i:i.K.c'r::n  rrv   AND  KONTCKX   HAY'S 

te>tin<:  it  is  advisable  that  the  exploring  electrode  be  connected  with  the 
negative  pole  of  the  secondary  current.  The  strength  of  the  current 
i>  uradualiv  increased  until  the  beginning  of  excitation  is  reached,  and 
the  number  of  millimeters  that  the  secondary  covers  the  primary  is 
noted.  A  comparison  of  the  two  sides  of  the  body  is  always  advisable 
in  carrying  out  tots  with  the  faradic  current,  since  accurate  methods 
ol  measurement  are  not  usually  available  apart  from  a  physiologic 
laboratory.  St  hit  xiim~  has  given  t  a  hies  for  the  faradic  current  as  follows, 
the  figures  referring  to  his  own  coil: 

FARADIC   i:\ClTAniJ.lTV  OF  XKRVKS.      *Xt!ntzing.} 

Borxn  ARIES. 

f" pin  r.  Loiri-r. 

(Millimeters    between     the 

primary  and  secondary 

coils.) 

1.  Spinal    fim'ssory  .  .  .  H">  130 

2.  MiiMMilucinaiicmis  .  .  14,-)  12.i 
:;.  Mental    .  .140  125 

1.  I'lnar  I.  140  120 

.->.  I'lnar  II.  .  130  107 

ii.  Frniual  .  137  120 

7.  Zyp.malic  13")  11.") 

v.  NlY.lian  .  13")  110 

'.'.  IVruncal  .     .  127  103 

III.  Cr  iral  ....  120  103 

i  I.  Til.ial                                                                         120  <)"> 

12.  Railial                                                                           120  «»() 

;:;  Facial.                                                         132  110 

In   testing  with  the  galvanic  current,  we  follow  out  the  same  pro- 

v.    fir.-t    obtaining  the  minimum   reaction,   and   then   ascertaining 

;:   the  force  of  muscular  contraction  follows  out  the  law  of  progression, 

('('('     A( '( '     ,\(>C    ('(»('    (cathodal  closure  contraction   is   greater   than 

aiiodal  eh  isure  cont  ract  ion.  etc. ). 

The  strength  of  the  current  necessary  to  produce  a  reaction  is  then 
read  off  on  the  milliamperemeter.  Thus  a  record  of  a  radial  nerve  may 
read  ;;-  !'  illou>  : 


(Minimal  <:;'lM>d:il  closui'e  contraction  occurs  with  2  ma.,  etc.) 

\\<'  have  -ecu  that   variations  in  com  ract  ion  in  diseased  conditions 

to    the    fjiiantity,    as     to    the    (|iialitv.    or    both.      Thus. 

nil.    or    abolition    of    contraction     mav    result.      For 

*'    in   contractility  is    obtained   in   st  rvchmn-poison- 

iii    tetaiiy,    and    oilier    affections    io    which    attention 

''  '.      Such    an    increase   is   determined    by   comparison 

1    .      A  decrease  in  nerve  excitability  is  obtained  in  many 

*'  neiirii         •    [iol  io  my  el  it  is,  etc.,  \\  hile  an  abolit  ion  may  be  present 

in  ' In  •      •  •    ' 

',-    coiisisl   m  variations   in   the   form  of  contrac- 
i"ii,  -ui-ii  a.-  r>loune--,  and  variation  from   the  typic  iral\'anic  formula. 


ELECTRICITY    IN    DISEASES    OF    THE    NEKVOUS    SYSTEM  401 

A  complex  reaction,  both  as  to  slowness  and  variation  from  the  typic 
formula,  constitutes  the  well-known  rcactio'n  of  degeneration. 

Reaction  of  Degeneration. — This  may  he  recognized  as  existing 
in  several  decrees  which  have  been  arbitrarily  named  slight,  medium, 
and  severe1. 

Anomalies  of  Fa m< lie  E.rcilahiliti/. — These  may  be  discussed  before 
the  main  subject  of  the'  reaction  of  degeneration  syndrome  is  con- 
sidered. They  consist,  in  the  main,  of  hyperexcitability  and  faradic 
loss,  or  the  phenomenon  of  exhaustion. 

Faradic  hyperexcitability  is  found  in  conditions  in  which  muscular 
rigidity  is  usually  accompanied  by  an  increase  in  tendon  excitability, 
such  as  is  seen  in  tetany,  in  tetanus,  in  many  of  the  occupation  neuroses 
(writer's  cramp,  telegrapher's  cramp,  violinist's  cramp),  in  paralytic 
posthemiplegic  states,  both  of  recent  and  of  remote  origin,  and  in  those 
cases  in  which  irregular  involvement  of  the  pyramidal  tracts  (post- 
hemiplegic chorea,  posthemiplegic  athetosis,  posthemiplegic  pseudo- 
paralysis  agitans)  takes  place. 

Faradic  exhaustion  is  a  constant  symptom  in  many  myopathics.  in 
many  tabetics,  in  myasthenias,  in  Thomsen's  disease,  and  in  a  number 
of  conditions  which  show  reaction  of  degeneration. 

Anomalies  of  Galvanic  Contractibilitif. — Galvanic  hyperexcitability 
has  been  spoken  of.  In  addition  to  the  disorders  mentioned,  it  is  a 
frequent  accompaniment  of  conditions  in  which  mechanic  hyper- 
excitability is  also  present,  in  multiple  sclerosis,  in  spastic  paraplegic 
states.  Galvanic  loss  is  a  constant  accompaniment  of  the  terminal 
stages  of  neuro muscular  degeneration. 

Galvanic  Inversion. — Rich's  Formula. — In  some  instances  the  phy- 
siologic order  of  (TV  A(  V>AOO  >COO  may  be  partially  inverted  to 
read  ACOCCOAOOCOC;  or  when  ACC>CCOCOOAOC  occurs. 
a  total  inversion  has  taken  place.  In  some  instances  the  formula  des- 
cribed by  Rich  is  present,  as  follows:  (VC  >ACC  ACKWOC.  These 
inversions  are  all  varieties  of  the  reaction  of  degeneration,  and  their 
presence  is  an  indication  of  a  degeneration  occurring  in  the  lower  motor 
neuron,  either  in  the  ganglion-cells  of  the  anterior  columns  of  the  cord 
or  of  the  nerve-fibers  passing  from  these  cells  to  the  muscle.  It  is  absent 
in  affections  of  the  primary  motor  neuron  system  per  se.  If  the  re- 
searches of  lotyko  are  correct,  the  reaction  of  degeneration  may  be  in- 
terpreted as  a  failure  in  the  striated  elements  of  the  muscles  to  react, 
with  a  persistence  of  sarcoplasmic  irritability. 

Longitudinal  Reaction. — This  special  application,  first  referred  to 
by  Remak.  occurs  in  those  muscles  which  show  the  reaction  of  degenera- 
tion. In  such  muscles  the  contraction  is  more  readily  brought  about 
when  the  testing  electrode  is  applied  at  the  distal  end  of  the  muscle, 
rather  than  when  the  application  is  made  to  the  motor  point,  which 
latter  has.  as  Doumer  has  termed  it.  lost  its  importance.  The  im- 
portance of  the  longitudinal  reaction,  which  is  great,  is  that  it  is  a 
more  delicate  test,  and  that  in  old.  long-standing  cases,  in  which  the 
nerve  paralysis  is  marked,  as  in  chronic  neuritis,  old  poliomyelitis,  etc.. 
contractions  may  be  brought  out  though  they  fail  when  the  electrode 
is  applied  to  the  motor  point.  In  certain  cases  of  sluggish  reaction  the 
longitudinal  reaction  test  should  be  employed  to  settle  a  doubt  as  to  the 
presence  of  reaction  of  degeneration.  Tims,  if  a  stronger  and  slower 
contraction  takes  place  with  the  electrode  at  the  distal  end  of  the  muscle 


4t')2  MKDICAI.    KLKCTH1CITY    AND    HONTGKN    RAYS 

than  when  placed  over  the  motor  point,  reaction  of  degeneration  is 
posit  ively  shown. 

In  practical  work  on  electric  testing  a  number  of  anomalous  and 
contradictory  results  have  been  obtained,  and  it  is  quite  certain  that 
the  entire  subject  of  the  reaction  of  degeneration  is  in  need  of  new 
restating.  At  the  present  time  newer  results,  which  have  come  about 
bv  the  Use  of  Leduc'-  new  commutator,  have  not  been  codified,  but  thev 
are  certainlv  de-tmed  to  be  ot  immense  practical  use.  \\  e  have  al- 
ready alluded  tn  the  fact  that  more  accurate  determinations  are  pos- 
sible by  this  form  of  apparatus,  and  data  are  now  rapidly  accumulat- 
/  _  as  in  i  he  minimal  duration  of  current  needed  to  make  visible  mus- 
cular contractions,  and  as  to  the  critical  frequency  at  which  an  inter- 
rupted current  cause-  a  muscle  response. 

l)i  rdn/itm  nt  of  HI  iictio-n  of  Degeneration.— Thi*  syndrome  has 
a  more  or  less  regular  course  of  development,  both  as  regards  the 
nerve  n  action  and  the  muscle  reaction  in  point  of  time  and  in  course 
of  events.  Both  of  these  are  conditioned  bv  the  character  and  the 
severity  of  the  lesion.  Following  the  complete  section  of  a  nerve- 
..  there  i-  usually  a  short  period  of  increased  irritability  in  the  nerve 
to  both  faradic  and  galvanic  currents.  This  may  persist  for  a  few 
days  three  or  four  -  and  is  then  followed  by  the  period  of  diminution, 
the  decline  reaching  the  normal  about  the  fifth  or  sixth  day.  and  then 
lly  sinking  below,  so  that  about  the  tenth  day  the  nervous  irrita- 
bility has  completely  disappeared. 

The  course  met  with  in  tin  mnxdcx  is  somewhat  modified.  Faradic 
excitability  seems  to  diminish  from  the  very  onset,  and  has  disappeared 
entirely  in  about  a  week  or  ten  days,  while  the  reaction  to  ualvanic 
currents,  which  has  steadily  decreased  for  about  a  week,  then  under- 
goes a  more  or  less  abrupt  reversal,  and  an  increase  in  excitability 
with  -bluish  contractions  takes  place,  mechanic  irritability  of  the 
e  appears,  mid  A('C  ('('('  appears  in  many  instances.  Rich's 
inverse  formula  begins  to  appear,  and  this  may  persist  for  some  time 
(•ven  for  weeks.  Later,  diminution,  j^oinjz  on  to  abolition,  takes 

Sherriiu:ion.    in    his    Krasmus   Wilson    lectures.'    has    trone  over  this 

:      '  '    n     :.:-   cases   of    nerve   section,    and    has    found    that    the    muscles 

ed  cease  to  respond  to  the  faradic  current   in  from  four  to  seven 

'i       -.  atid    ':.;  '.   even    v.nh   the   iralvaiiic  current,   there   mav   be  loss  ot 

r  t  lii    tenth  day.     The  appearance  of  slu.u<>ish  muscular 

'    on  1 1  e  reversal  of  pola  nt  v  1  a  kes  place  about  1  he  same  t  line. 

I':    'he    •  tial    -taLies   of  degeneration    the   ti'alvalilc   excitability   dimin- 

I  :.'    A<  X  '  •  r-i   disappears  ent  irelv,  and   is  soon  followed  by  t  he 

e  ( '(  ii       i. d   the  ('<"('.   i  he   A< '( '   persisting   the  longest.     The 

•     may  -till  be  pronounced,  even  aftei1  the  complete 

'  'he   \( '( '.      Ihe  lonnit  uduial  react  ion  finally  disappears. 

.,     showji  b\   ( iiiilleminoi  (p.  :!]s.  Knulish  trans- 

pecial  i  yi  ie  of  elect  ric  and  mechanic 
Ki'i  i  as  cha  I'act  enst  ic  of  pat  lent  s 
•.   or    m\ ' it ' iina    con^enita.       In   t  h<'se 
die  and  L;al  va  me  elect  licit}" 
m'c  excit  al  lility  as  \\ell,  but   t  here  is  a 
Miircli,  inuii. 


ELECTRICITY    IX    DISEASES    OF    THE    NERVOUS    SYSTEM  463 

distinct  increase  of  the  muscular  excitability  to  these  forms  of  stimula- 
tion. Testing  with  the  galvanic  current  shows  that  the  muscles  react 
only  with  the  closure  contractions,  the  A(X1  =  CCC.  The  tonic,  slow, 
and  prolonged  nature  of  the  contractions  is  pathognomonic.  When 
stimulated  by  the  faradic  current  the  muscles  respond  normally 
to  minimal  contractions,  but  on  increasing  the  strength  of  the  current 
the  reaction  becomes  markedly  prolonged,  persisting  for  a  number 
of  seconds  after  complete  removal  of  the  current.  This  period  of  dura- 
tion tetanus,  as  it  has  been  termed,  to  both  interrupted  and  continuous 
currents,  is  very  characteristic. 

M ijdxthcnic  Reaction. — Another  type  of  muscular  reaction  is  observed 
in  the  same  kind  of  patients,  and  in  a  number  of  conditions  closely 
allied  to  the  neuromuscular  affection  known  as  myasthenia  gravis. 
This  reaction  consists  in  the  great  fatigability  of  muscle  when  exposed 
to  the  tetanizing  action  of  a  persisting  faradic  current.  It  differs 
from  the  normal  physiologic  curve  by  the  very  rapid  onset  of  the 
fatigue  drop.  At  the  same  time  the  muscular  reaction  does  not  depart 
from  the  ordinary  type  on  exposure  to  the  single  shock  of  the  direct 
current,  notwithstanding  the  presence  of  tetanic  fatigue. 

Neurotonic  Reaction. — The  exact  significance  of  this  reaction  is 
unknown.  It  consists  in  the  tonic  persistence;  of  contraction  after 
cessation  of  the  current,  whether  it  be  faradic  or  galvanic.  Further, 
there  is  an  exaggeration  of  the  anodal  response,  made  evident  by  t he- 
early  appearance  of  AOC  and  A(V  tetanus. 

Reactions  in  Lesion*  of  Spinal  Xcrrc  Center*.-  Xot  only  does  the 
investigation  of  the  muscle  at  the  site  of  its  motor  points  offer  con- 
siderable information  concerning  the  condition  of  the  nerve-supply  of 
the  respective  muscles,  but  it  not  infrequently  happens  that  an  entire 
group  of  muscles  is  affected  by  the  loss  or  reduction  of  function,  and  a 
careful  study  of  a  reaction  of  these-  groups  will  lead  to  a  differential 
diagnosis  between  the  affection  of  the  peripheral  distribution  as  con- 
trasted with  a  lesion  of  the  motor  centers  in  the1  spinal  cord.  Thus 
it  is  well  known  that  electric  testing  of  groups  of  the  muscles  of  the  hand 
will  enable  one  to  differentiate  between  a  lesion  of  the  trunk  of  the 
median  nerve  and  a  lesion  of  the  first  dorsal  segment  in  the  spinal 
cord.  As  lias  been  well  pointed  out  by  many  authors,  in  the  latter 
case  the  whole  of  the  thenar  and  hypothenar  eminences  will  be  in- 
volved. ;is  well  as  all  the  interossei  and  lumbricales,  whereas  if  the 
lesion  is  confined  to  the  trunk  of  the  median  nerve,  then  the  hypothenar. 
the  interossei,  the  two  inner  lumbricales,  the  abductor  pollicis,  and  tin- 
inner  half  of  the  short  flexor  will  escape,  since  all  these  receive  fibers 
from  the  ulnar  nerve.  It.  therefore,  becomes  a  matter  of  considerable 
importance  in  the  differential  diagnosis  of  peripheral  lesions  due  TO 
neuritic  process,  from  central  lesions  due  to  myelitic  process,  to  bear 
in  mind  the  segment  al  distribution  of  the  motor  centers  in  the  spinal 
cord,  \\hile  most  of  these  facts  are  commonplaces  for  the  neurolo- 
gist, and  have  been  very  carefully  investigated  by  followers  of  this 
branch  of  medicine,  it  is  essential,  in  the  electric  study  of  the  diseased 


4f)4  MHDK  AI.     KI.KCTKKTI'Y    AM)    H<").\T< ,  EX    HAYS 

Il.TI!     CKK-    IV.  CKKVICAI..    V.  <  KKVHAI..    VI.  ( 'KKVICAI..   VII.   CKKVI-   VII  I.  CKK-       DORSAL. 

\  11    \i..  CAI-.  VK'AI,. 


•  i'  ;-  Scrratu-  Second     to 

iLr  Minn.  twelftll 

•  .•!:.-.  .   .      I'.-rt.  iclav.).  dorsal. 

-  minor,      I'ronator.-.          Pronators.  Mu-cles     of 

Tricep-.  Triceps.  back     and 

Hrach.  ant.        Hnich.  ant.  abdomen. 

I.c.nir   cxti-n-      I.OIIK     flex-      Long     flex- 
sor-  of  or-  of  ors  of 

wri-t.  wrist     and        wrist     and      First      clor- 

h'nuors.  finirers.  sal. 

Extensor  of      Extensor  of 
tliuinh.  thumb. 

In  t  ri  nsic 
mtisfles  of 
hands. 


IV.    I.fMHAH.  \.    I.fMBAK. 


Fsoas. 
Iliacus. 

Sartorin-. 

(,)uad.  ext .  cruri-.        (^uad.  ext .  <  ruri-. 

Obturator.  Obturator. 

Adductor-.  Abductor-. 

(llutei.  Glutei. 

Bicep-  femori.- 

Semitend. 

Popliteus. 


1 1.  S  \<"KM..  II  I.  S  \'  K  \i..  I\'.  and  \'.  SAfKAi.. 


Sphincter        ani        et 
vesica1. 

I'erineal  muscles. 


Reaction  of  Sensory  Nerves.  Just  :is  the  reaction  of  the  neuro- 
inu-culur  :ipp;tr;it  us  to  cleft  ric  stimulation  is  cvidencc'd  by  muscular 
f  on' r;ift  ion,  so  the  reaction  o\  the  sensory  neurons  is  made  known  by 
sensations.  In  practical  \vork,  since  mixed  nerves  are  usually  in- 
volved,  the  two  sets  of  phenomena  are  constantly  present.  As  is 
the  case  v.ith  muMMilar  phenomena,  so  with  the  sensory  symptoms, 
'•'  :'  lin  '  ;iri  tinns  in  health  and  disease  are  known.  'J'hese  sensations 
are  thuiiLrht  to  be  lar(_reh'  dependent  upon  chemic  changes,  and  hence 
they  are  u-uallv  more  apparent  at  the  more  definitely  chemic  terminal  of 
the  electric  apparatus  the  cathode.  They  vary  according;  to  the 
•-i  •  of  the  elcftrode  used,  bcinir  more  distinct  with  the  smaller 
elect  rode,  by  reason  of  the  condensation  of  current,  also  with  the 
nature  o!  the  electric  force  emploved.  Thus  the  sensation  accom- 
panvintr  ';'  u-e  of  the  mild  Lralvamc  current  is  usiialk-  described  as 
•  •  1 1  at  of  creeping  or  prickling  more  nearly  dcscribos 
the  normal  -<  n  •  ••  -  iinluceil  bv  the  mild  faradic  current.  A  further 


ELECTRICITY    IX    DISEASES    OF    THE    XERVOUS    SYSTEM  405 

variation  exists  if  different  solutions  for  contact  are  applied,  due  to 
the  dissociation  of  different  ions.1 

Thus,  if  ordinary  salt  solution  bo  employed,  the  sensations  are 
more  active  at  the  anode,  since  the  dissociated  sodium  ions  enter  at 
that  pole;  while  if  sodium  carbonate  be  used,  the  COa  ions  entering  at 
the  cathode  cause  a  "'router  amount  of  sensation  at  that  pole.  The 
contact,  whether  complete  or  partial,  also  alters  the  sensation  some- 
what, perfect  contacts  being  usually  much  less  painful  than  imperfect 
ones.  Alterations  in  the  rapidity  of  interruption  make  a  grout  differ- 
ence in  the  sensations  produced  on  the  skin.  Single  shocks  are  often 
extremely  painful,  oven  apart  from  the  muscular  effects  produced. 
When  the  interruptions  commence  to  be  more  rapid  than  fifty  to  the 
second,  the  sensations  cease  to  bo  individualized,  fusion  takes  place-, 
and  with  still  more  rapid  interruptions  a  pleusunt,  smooth  glow  may  be 
alone  experienced,  or  with  more  rapid  interruptions  numbness  or 
anesthesia  may  be  produced.  Leduc's  currents  for  local  anesthesia 
are  particularly  pleasant  in  application. 

Protopathic  and  Epicritic  Sensibility. — An  extremely  important, 
if  not  epoch-making,  research  of  Head-  has  opened  up  an  entirely  new 
and  wide  field  for  investigation  with  reference  to  the  electric  excitability 
of  the  sensory  nerves,  and  has  enriched  clinical  neurology  with  a  new 
classification  of  sensory  nerves  heretofore  unrecognized.  Thus  he  has 
described  two  sets  which  he  has  termed  the  epicritic  and  the  protopathic 
sensory  systems.  These  show  marked  differences  in  their  response  to 
electric  stimulation,  and  our  present  accounts  of  sensory  nerve  phys- 
iology with  reference  to  electric  stimulation  will  receive  an  entirely 
new  series  of  interpretations. 

Head's  views  concerning  these  two  sets  of  sensory  nerves  may 
be  briefly  summarized  us  follows:  Ordinary  sensations  of  touch  are 
not  simple  and  primary,  but  consist  of  at  least  two  forms  of  sensibility, 
which  have  been  termed  by  him  protopathic  and  epicritic,  and  which 
sensations  are  dependent  upon  two  distinct  systems  of  fibers.  He 
was  led  to  this  differentiation  by  a  large  series  of  studies  on  peripheral 
nerve  injuries,  and  subjected  his  findings  to  an  exceedingly  critical 
control  by  operating  upon  a  cutaneous  nerve  of  his  own  arm.  The 
processes  of  degeneration  and  regeneration  wore  carefully  studied,  and 
the  modifications  in  sensibility  and  electric  reaction  made  the  basis  of  an 
elaborate  monograph.  As  protopathic  sensibilitif  he  describes  that  form 
of  sensibility  which  can  produce  changes  in  consciousness,  but  which 
is  incapable  of  causing  a  quantitative  change  apart  from  the  area  studied. 
The  position  of  a  point  stimulated  can  be  appreciated,  and  each  stimulus 
causes  a  widespread  radiating  sensation,  not  infrequently  referred  to 
parts  at  a  distance.  The  return  of  protopathic  sensibility  to  a  part, 
after  its  loss,  brings  a  cessation  of  all  those  destructive  changes  in 
nutrition  that  occur  in  parts  whore  the  skin  is  insensitive.  Ulcers 
cease  to  form,  and  sores  heal  as  readily  as  on  the  healthy  skin,  although 
the  parts  remain  insensitive  to  all  higher  forms  of  stimulation,  such  a< 
liii'ht  touch. 

After  an  affected  part  has  remained  for  a  variable  period  in  this 
condition,  it  begins  to  become  sensitive  to  light  touch,  and  degrees  of 

1  Sec  Sanchez.  La  theorie  des  ions  on  elect ririte  medieale,  Nantes,  11)02;  Leduc, 
lonization  Modicales.  Monographies  Medieales,  liU)7. 

2  Brain,   1  !>().).     See  also  his  previous  and  subsequent  papers. 

30 


MEDICAL    ELECTRICITY    AM)    ROXTCKN    HAYS 

temperature  which  produce  the  sensations  called  warm  and  cool  on  the 
normal  skin  are  again  distinguished  correctly  one  from  another.  With 
the  gradual  return  of  sensation  it  again  becomes  possible  to  discriminate 
two  points  touching  the  skin  at  distances  more  nearly  normal,  and  thy 
widespread  radiation,  so  characteristic  ot  the  first  stage  of  recovery 
after  the  severance  of  a  peripheral  sensory  nerve,  ceases,  and  is  replaced 
1  iy  an  increasing  accuracy  of  localization.  It  is  for  this  form  of  sensation 
that  Head  has  propo.-ed  the  term  t  ]>icritic. 

Head  comes  to  the  general  conclusion  that  the  sensory  mechanism 
consists  of  three  systems:  (I)  Deep  sensibility,  capable  of  answering 
to  pressure  and  tot  he  movements  of  parts,  and  even  capable  of  producing 
pain  under  the  influence  of  excessive  pressure,  or  when  a  joint  is  injured. 
The  fibet>  subserving  this  form  of  sensation  run  mainly  with  the  motor 
nerves,  and  are  not  destroyed  by  division  of  all  the  sensory  nerves  of  the 
skin. 

(II)  Protopathic  sensibility,  capable  of  responding  to  painful  cutan- 
eous stimuli  and  to  the  extremes  of  heat  and  cold.     This  is  the  great 
reflex  system,   producing  a   rapid,   widely  diffused   response,   unaccom- 
panied by  an\'  definite  appreciation  of  the  locality  of  the  spot  stimu- 
lated. 

(III )  Kpicritic  sensibility — by  which  we  gain  the  power  of  cutaneous 
localization,  of  the  discrimination  of  two  points,  and  of  the  finer  grades 
of  temperature  called  cool  and  warm. 

With  reference  to  their  distribution,  the  entire  body,  without  and 
within,  i-  supplied  bv  the  protopathic  system.  The  fibers  of  this  sys- 
tem  in  the  skin  may  be  spoken  of  as  somatic,  those  of  the  internal 
organs  as  visceral,  protopathic  fibers.  Thus  one  should  speak  no 
longer  of  the  afferent  sympathetic  system,  but  of  the  protopathic  supply 
of  t  he  internal  organs. 

Another  set  of  fibers  peculiarly  associated  with  impulses  of  niove- 
1  •'•!.'  and  of  pressure  exist  in  connection  with  the  Paccinian  organs. 
!'.  the  bod}  and  limbs  an  analogous  system  is  found,  peculiarly  liable 
to  pressure,  to  the  localization  of  movement,  and  to  the  appreciation 
ot  posit  inn.  The  fibers  in  this  system  run  in  conjunct  ion  with  the  motor 

e>. 

In  addition  to  these  two  systems,  which  are  distributed  to  all  parts 

1  '  t  he  body  wit  hin  and  wit  hout ,  the  surface  of  the  body  only  is  supplied 

e  epicrit ic  system.     This  endows  the  skin  with  sensibility 

.:  '    tniich.      To  the  impulses  conducted  by  this  system  is  due  the 

1  :.:   the  position  of  cutaneous  stimuli,  of  di-ceriumr  the 

two  points,  and  ot  discriminating  between  minor  degrees 

•     '      '  •,   i-n  •:.   and  other  -pecial  attribute-  of  -ensatioti.      The  fibers 

'<•):     ••'•    more   ea>ily    injured,    and    regenerate    more   -lowly 

rotopathic  sv-tem.      Thev  ale  evidently  more  highly 

roach  more  nearly  to  the  motor  libers  which  supply 

.'  '    •       •        •!••-  in  the  time  required  for  their  regeneration. 

i'-'   d  iffe  retire  in  t  hese  t  wo  syst  ems  In  elect  ric  st  imula- 

•  •  rni  pied  currents.      I 'rot  opal  hie  sensibility  does  not 

iy  -;i<'ii   currents  whose  duration   i-  less  than  ().(>f)2 

-•  •'  /'lent  1  v  current  waves  having  that  du  rat  ion  or  less 


•li    i-   more  or  less  uevnui  oi    painful   impres- 
impul-c  decreases,  thouu'h  they  are  still  felt 


ELECTRICITY    IN    DISEASES    OF    THE    XKUVOUS    SYSTEM  407 

,S\  n.sor//  AYnr  Reaction*. — These  may  be  determined  for  the  galvanic 
current  by  means  of  a  wire  brush  attached  to  the  cathode.  The  anode, 
usually  a  wet  sponge,  being  placed  in  the  hand  or  on  the  sternum. 
The  quantity  of  current  which  is  regulated  by  a  rheostat  in  series  or  by 
a  shunt  gives  the  figures  for  minimal  pain  reaction.  The  varying  do- 
grees  of  skin  resistance  render  this  method  irregular  as  to  results. 

Testing  by  the  faradic  current  is  done  by  the  examining  electrode, 
and  the  strength  determined  by  the  movement  of  the  secondary  coil 
on  the  primary.  The  amount  of  separation  of  the  coils  affords  a 
measure  of  the  strength  of  the  current  necessary  to  produce  minimal 
sensations. 

Krb's  table  of  normal  faradic  excitability  is  given  as  follows: 

,,  FIKST  SF.NSATION —  MAUKED  PAIN  — 

PLACE  OF  EXAMINATION.  SEPARATION  OF  COILS.  SEPARATION  OF  COILS. 

Check                 200-220  mm.  120  mm. 

Neck    i 1SO-220  "                               120     " 

Ann 200  mm.  120     " 

Fort-arm 190     "  •  11.") 

Dorsiim  of  hand 17.")  110 

Tip  of  fimrer 125     "  <KJ     " 

Abdomen 190     "  120     " 

Leg 170     "  110 

Dorsuin  of  foot 17")     ''  1 10 

Sole  of  foot 110     "  SO     " 

Modifications  in  the  Effect  of  Faradic  ('iirrcnl*. — Muscular  contrac- 
tion is  chiefly  produced  by  the  use  of  a  faradic  coil  with  coarse  wire  or 
one  with  a  small  length  of  secondary  wire,  perhaps  1500  feet.  It  is  not 
produced  at  all,  or  not  to  the  same  extent,  if  a  coil  with  fine  wire  or 
one  with  a  great  length  of  secondary  wire,  say  8000  feet,  is  used.  Slow 
vibrations  favor  muscular  contraction  and  the  most  rapid  interruptions 
aid  in  preventing  it.  Faradic  currents  from  a  coil  with  fine  wire  and 
extremely  rapid  interruptions  have  an  effect  upon  the  nerve  which  is 
very  beneficial  in  neuralgia  and  neuritis. 

A  faradic,  current  of  a  quality  to  produce  muscular  contraction  may 
have  its  strength  regulated  by  motion  of  the  secondary  coil  upon  a  sort 
of  sledge.  When  the  secondary  coil  is  very  far  from  the  primary  coil 
the  current  may  bo  so  weak  as  not  to  cause  contraction. 

Sensory  perception  follows  a  law  comparable  to  the  law  of  muscular 
irritability  so  far  as  the  epieritic  sensations  are  concerned.  To  galvanic 
currents  the  first  sensation  is  noted,  according  to  Bordier's  researches, 
as  follows:  ('('IS.  AnCS,  AnOS.  COS. 

Segmental  Distribution  of  Sensory  Nerves.  -The  researches  of 
Starr.  Kocher,  Thoburn,  and.  more  recently,  of  Head  and  Sherrington 
have  served  to  bring  out  a  series  of  facts  concerning  the  relationship 
of  the  segment al  distribution  of  the  sensory  nervous  system.  Each 
segment  of  the  spinal  cord  has  a  more  <>'•  les>  regular  segmental  repre- 
sentation in  the  periphery.  Klectric  testing  for  distribution  of  sensa- 
tion has  not  advanced,  so  far  as  practical  clinical  purposes  are  concerned, 
to  the  same  degree  as  motor  tests,  but  a  careful  study  of  these  segmental 
areas  in  the  skin  affords  a  very  important  means  of  diagnosis  of  both 
peripheral  and  central  lesions.  The  spinal  s^menta!  distribution  of  the 
sensory  nerve  areas  do  not  at  all  <  oincide  with  the  peripheral  distribu- 
tion of  the  sensory  nerves.  (See  Figs.  l>07.  30S,  oO<),  and  Plate  !).) 


408 


MKDIC.VL    KLKCTHH'ITV    AND    RONTGEN    RAYS 


Nerves  of  Special  Sense.— The  reaction  of  nerves  of  special  sense 
is  individual  ami  specific.  Klectric  stimulation  of  the  olfactory  nerve 
is  of  lit tk-  known  practical  value.  The  sensation  of  the  smell  of  phos- 
phorus is  often  given  as  an  approximate  description  of  this  reaction 
sensation. 

<>l>tit'nl  stimulation  results  in  a  sensation  of  a  flash  of  light.  Ac- 
cording to  the  direction  of  the  current,  certain  differences  have  been 
observed,  but  marked  individual  variation  undoubtedly  exists.  C'ath- 


ui< •  i-  !  li»:i*_dii  to  give  a  reddish  flash,  and  anodal  closure'  a  bluish 
l»ien,er  lias  constructed  special  formulas  for  the  reactions  of 
•rve  r-t  imulai  ion.  (V  and  A< )  over  the  closed  eye,  he  states, 
•!  <•<  pt  ion  cit  ;i  li^ht  central  disk,  surrounded  by  a  narrow  fainter 
( '<  )  ami  .\('  cause  a  weaker  perception  in  an  inverse  order. 
stimulation  of  the  eye  with  strong  currents  is  not  without  its 
danger-,  blindness,  presumably  from  retinal  hemorrhage,  having 
ported  hv  a  number  of  observers  from  Duchenne's  time  to  the 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM 


469 


present.     From    a   diagnostic   standpoint   optical   electric   testing   has 
given  few  definite  results. 

Auditon/  stimulation  requires  strong  currents  and  results  in  per- 
ception of  sounds,  as  of  whistling,  blowing  or  buz/ing,  being  most 
pronounced  to  (V,  less  so  to  AO,  A('l  and  CO  give  no  results  in  health 
Many  individuals  give  no  reactions  whatever.  In  pathologic  states, 
particularly  in  perforation,  the  reaction  is  usually  more  pronounced, 


Auriculotemporil  3  V. 
Sm.lJ  occipital  C.  P. 


Lateral  brunches  of  intercostal 


Posterior  tibial  S.  P. 


Fin.  30S.— Cutuneoi 


fttT   Flower). 


constituting  a  distinct  hyperesthesia  of  the  auditory  nerve.  In  some 
instances  of  hyperesthesia  ATI  and  ('().  which  normally  give  no  re- 
sponse, may  do  so. 

Loss  of  auditory  excitability  may  be  encountered,  and  an  inversion 
of  the  formula  has  been  noted  in  rare  cases  ot  inexact  significance,  and 
what  is  known  as  a  paradoxic  reaction  is  known  in  which  the  opposite 
ear  reacts,  while  that  to  which  the  electrode  is  applied  does  not  respond, 
or  only  feebly.  Voltaic  vertigo  is  described  ()tl  l);'g'e  39">. 


470 


MKDICAL    KLKCTKICITY    AND    RON'TGEN    RAYS 


(inxtatnrii  perception  may  he  aroused  by  elect  rie  stiinuhition,  both 

\vh<-n  1  he  tongue  is  si  nnulatcd  and  when  t  lie  elect  rodrs  are  applied  to  tin- 
back  oi  the  neck.  One  of  1  he  author's  patients  always  noted  a  metal- 
lic taste  when  electrodes  were  applied  to  the  forehead  and  epigastrium. 


•C.IV 


c.v 


C.VI 


Stiniuliilion   bv   the  anode  causes  an  acid    metallic  taste;    bv  the  cath- 


od<-.    an        kaline    bitter    taste.       Such    LMistatorv    seii-ations    mav    be 


arouserl  liv  minimal  currents  and  ma\'  be  subject  to  loss. 


DISEASE   OF  THE   PERIPHERAL  SENSORY   NERVES 

Anesthesia  is  brst  treated  bv  a  faradic  brush  electrode. 


DIAGNOSIS  AND  TREATMENT  OF  DISEASES  OF  PERIPHERAL  MOTOR  NERVES 

AND  MOTOR  CENTERS 


Palsies   of    Cranial   Nerves 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  471 

often    involved  centrally,  although  following   many  toxemias  the  per- 
ipheral distributions  of  the  third,  fourth,  or  sixth  may  be  affected. 

Ocular  Muscles. — There  are  many  difficulties  surrounding  the 
investigation  of  the  eye  muscles.  The  sensitiveness  of  the  conjunctiva 
and  cornea,  the  delicacy  of  the  retina,  and  the  deep  seat  of  the  eyeball 
itself  all  make  the  study  of  the  ocular  palsies  difficult  and  exasperating. 
The  intricacy  of  the  innervation  plays  an  important  part  as  well.  It 
is  convenient  to  consider  the  third,  fourth,  and  sixth  nerves  together, 
since  they  are  so  closely  allied  in  their  functions.  The  third  nerve  has 
the  widest  distribution,  supplying  all  the  external  muscles  of  the  eye 
save  the  superior  oblique,  which  is  supplied  by  the  fourth,  and  the 
external  rectus,  which  is  supplied  by  the  sixth  nerve.  The  voluntary 
part  of  the  levator  palpebne  superior  is  also  supplied  by  the  third; 
the  involuntary  part,  by  the  cervical  sympathetic  nerves.  The  third 
nerve  also  goes  to  the  interior  of  the  eye,  supplying,  through  the  ciliary 
ganglion,  the  ciliary  muscle  and  the  sphincter  pupilhe.  The  ciliary 
ganglion  is  at  present  considered  by  a  number  of  scholars  to  be  the 
peripheral  motor  nucleus  for  the  sphincter  pupilhe. 

Complete  paralysis  of  the  third  nerve  gives  ptosis,  external  strabis- 
mus, inability  of  the  globe  to  move  upward,  straight  down,  or  decidedly 
inward.  The  pupil  is  dilated  and  does  not  contract  on  exposure  to  light. 
Complete  paralysis  is  rare1.  Hysteric  paralysis  is  not  unusual,  but  so  far 
as  the  ptosis  is  concerned,  is  usually  differentiated  from  organic  paral- 
ysis by  the  absence  of  an  overacting  levator  of  the  other  side. 

Electric  tests  are  unavailing  in  determining  the  peripheral  or  central 
character  of  a  third-nerve  paralysis,  although  the  longitudinal  reaction 
has  been  obtained  in  levator  palpebne  paralysis. 

In  nuclear  lesions  it  is  important  to  bear  in  mind  that  the  orbicularis 
oculi  is  also  involved.  Transient  ocular  palsies,  such  as  occur  in  oph- 
thalmic migraine,  should  not  be  confounded  with  true  ocular  palsies. 

Foiirth-ncrn'  /;rm;///.s/x  causes  a  characteristic  diplopia,  which  is  not 
capable  of  electric  analysis. 

Xi.rth-nrrrc  pdralt/xix — paralysis  of  the  external  rectus — causes  a 
characteristic  and  isolated  internal  squint. 

Tht-rnpi/. — These  ocular  palsies  may  be  treated  by  electric  stimula- 
tion, but  it  cannot  be  said  that  the  treatment  is  always  satisfactory. 
Only  after  thorough  antisyphilitic  and  antirheumatic  treatments 
have  been  persistently  carried  out  is  one  warranted  in  trying  elec- 
tricity. Even  in  hysteric  ptosis  one  is  not  warranted  in  abusing  the 
electric  treatment  for  fear  of  excess  of  suggestion.  Electric  stimula- 
tion of  the  levator  palpebne  is  at  times  useful.  Such  electric  stimula- 
tion as  recommended  bv  Everthain  and  Salomonson  should  be  done 
by  a  button  electrode  applied  about  }-  inch  under  the  highest  part  of  the 
supra-orbital  arch. 

The   method   followed   for  treatment    of   the  ocular  palsies   by  elec- 
direct  application  of  the 
at   the  nap*1  of  the  nee  I 
sponges  may  be 


uccessful  result: 


M'luihry.    Bulletin   ofiiciel    de    la    Socicte    Frunraise   d'elec-trot  lirrupic,    n 
190o. 


172  MKOH'AL    KI,K(TKieJTY    AND    HONTCiKN    HAYS 

Facial  Nerve.  This  nerve  is  more  frequently  subject  to  disease 
than  any  other  cranial  nerve. 

The  lesion  itself  may  be  treated  by  bilateral  stimulation  with 
galvanic  currents.  An  electrode  about  2  cm.  (;'  inch)  in  diameter 
is  placed  in  each  auriciilomast oid  fossa,  the  negative  electrode  being 
on  the  affected  side.  A  current  of  (>  or  S  ma.  is  allowed  to  flow  for  five 
minutes. 

Flectricity  may  be  used  to  maintain  the  nutrition  of  the  paralyzed 
facial  muscles  and  hasten  the  return  of  power. 

In  cases  in  which  faradic  excitability  is  present  the  paralyzed 
muscles  may  be  exercised  by  faradic  currents  and  a  trophic  effect 
upon  them  may  be  secured  by  galvanic  currents.  One  of  the  best  ap- 
plications is  the  de  Watteville,  or  galvanofaradie  current,  rhythmic- 
ally varied  in  intensity  and  direction  by  the  rhythmic  rheostat  and 
pole-changer  or  some  similar  apparatus.  Tin  galvanic  current  has  a 
maximum  intensity  of  .">  or  6  ma.  and  the  faradic  coil  has  coarse  wire 
and  slow  interruptions  and  a  strength  of  current  sufficient  to  cause 
contraction  of  the  facial  muscles.  One  electrode  is  held  in  the  hand, 
and  the  other  is  applied  for  about  a  minute  to  the  motor  point  of  each 
of  the  paraly/ed  muscles.  In  the  absence  of  special  apparatus  the 
galvanic  and  faradic  currents  may  be  applied  separately.  Stimulation 
by  isolated  induction  shocks  or  by  condenser  discharges  are  more  valu- 
able in  treating  the  muscles  of  the  face  than  those  elsewhere.  These 
muscles  tire  short,  and  do  not  have  the  inertia  of  a  considerable  weight 
to  overcome.  The  abrupt  contraction  produced  by  the  applications 
i-  not.  therefore,  so  undesirable  as  it  is  elsewhere. 

/.*i>/iih(l  induction  >7mr/,-.s-  cause  contractions  which  are  much  more 
-uddeii  in  onset  and  subsidence  and  much  briefer  in  duration  than 
physiologic  contract  ions.  They  are  not  generally  desirable  in  elect  ro- 
mechanotherapy,  but  perhaps  are  all  right  for  exercising  the  small 
muscles  of  the  face  which  normally  do  not  have  much  resistance  to  be 
•  '  iTcome  by  i  heir  <•(  >nt  ract  it  m. 

I'aralvsis  of  the  entire  innervation  of  the  seventh  nerve  is  not  com- 
mon,  save   in   central   lesions:  paralyses  of  separate  branches  are  very 
I '  is  a  highly  complex  nerve,  and  is  probably  not  a  pure  mot  or 
n<-rve,   bill    has  a   sensory   root    as  well,   probably,  as   Hunt1    has  shown, 
ate  ganglion.      The  typic  involvements  of  the  facial  nerve 
1  •  (  Mitside  of  the  stvlomastoid   foramen,  leading  to  Bell's 
-is:     _'     within    the    Fallopian    canal:   (!•>)   between    its   emergence 
ion-  and  the  geiiiculate  ganglion,  and   (1)   within  the  pons. 
/!•         /nil.-/.  <lu<-  to   refrigeration,   to  injuries,   or  to  tumors. 
complete  palsy  of  the  muscles    of    the  corresponding  side  of  the 
intarv    and    emotional    impulse-.      On    looking    down. 
•  •    :  '  le  to  -hut    the  eve.   there  i-  even  a  slight    raising  of 

':  e  paraly/ed  side,  owing  to  the  unopposed   levator  pal- 
I  :.'•  '          i-  flattened  out  and  loses  all  its  wrinkles,  the  conjunc- 
:    cued,    and    the   eve    brims    with    tear-.      'I  he   evehds 
"  '•'!  pract  iralh   onl\   during  sleep,  when  t  he  levator  i-  relaxed, 
be    forced    out    of   the   pai'alvzed    side  of    the    cheek    he- 
•       :;  -i  ilal  lial   folds  are  obi  it  era  t  e.  1 . 
advantageous   in   determining   the  extent    ot    t  he 


ELECTRICITY    IN    DISEASES    OF   THE    NERVOUS    SYSTEM  473 

paralysis.  The  trunk  of  the  facial  may  be  tested  in  two  positions — 
(a)  In  the  angle1  between  the  descending  rainus  and  the  mastoid  process. 
Here  stimulation  produces  a  contraction  of  all  the  muscles  supplied 
by  the  facial,  although  contractions  of  the  muscles  of  the  upper  branches 
frontal  and  corrugator  supercilii — are  less  powerful  than  the  others. 
This  is  a  normal  phenomenon,  and  should  not  lead  to  a  misinterpreta- 
tion as  to  the  cont ractibility  of  these  muscles. 

(h)  A  second  point  is  at  the  tragus  of  the  ear.  Here  only  the  second 
and  third  branches  are  stimulated,  and  at  times  the  reaction  is  wanting 
cut  irely. 

The  three  hranchex  of  the  facial  may  each  be  tested  separately.  The 
stimulation  of  the  upper  branch  causes  wrinkling  of  the  forehead  and 
eyebrow:  that  of  the  middle'  branch,  at  a  point  just  beneath,  over 
the  tuber  ossis  /ygomatici,  causes  closing  of  the  eye,  smiling  movement, 
turning  up  of  the  angle  of  nose,  and  a  pout-like  wrinkling  of  the  upper 
lip:  stimulation  of  the  lower  branch  causes  turning  over  of  the  under 
lid,  lifting  of  the  chin,  and  drawing  of  the  mouth  downward  and  out- 
ward. In  making  these  tests  it  is  desirable  to  bear  in  mind  that  of  the 
three  branches,  the  upper  branch  is  the  most  excitable,  the  middle 
branch  I  he  least,  and,  further,  that  tests  with  the  faradic  current  are 
apt  to  be  painful,  and  that  with  the  galvanic  current  dizziness,  light 
Hashes,  etc.,  are  usual  unpleasant  by-effects.  Minimal  currents  should 
be  employed  in  all  tests  of  the  facial  innervation. 

Reaction  of  degeneration  is  often  found  very  early,  and  is  usually 
very  complete.  In  mild  cases  reaction  of  degeneration  may  be  absent. 
Reaction  of  degeneration  comes  on  slowly;  reaction  to  the  induction- 
coil  current  may  persist  for  a  week  or  ten  days,  and  no  prognostic  data 
are  obtainable  within  that  period.  Reaction  of  degeneration  of  irreg- 
ular distribution,  /.  c.,  involving  one  or  two  branches  only,  is  of  better 
prognostic  import,  as  a  rule,  than  when  the  three  branches  are  involved. 

Kleetric  treatment  is  highly  beneficial  in  most  cases  of  Hell's  palsy, 
electrically  treated  cases  nearly  always  recovering  more  rapidly  than 
untreated  cases.  Persisting  reaction  of  degeneration  should  lead  one 
to  investigate  thoroughly  as  to  the  cause1,  especially  if  it  has  been  hastily 
inferred  that  the  paralysis  is  due  to  refrigeration. 

The  cases  due  to  refrigeration  (cold)  have1  a  good  prognosis  in  the 
main.  The  treatment  should  be  carried  out  daily,  direct  applications 
\ieing  made  to  both  the  nerve-trunk  and  to  the  muscles.  Roth  faradic 
and  galvanic  currents  are  advisable1  in  those  cases  with  definite  reaction 
of  degeneration.  It  is  desirable  to  place  the  positive  electrode  on  the1 
nape  of  the  neck,  and  the1  negative  elee-trode  should  traverse1  the1  innerva- 
tion of  the1  affe'cte'd  branches  from  the'  evnter  to  the  periphery.  The 
author  has  had  very  great  success  with  the  slow  sinusoidal  current. 
Treatment  of  the  skin  and  muscle's  by  the1  induction-coil  is  also  ad- 
visable1. The  latter  alone  is  needed  if  reaction  <»!  degeneration  has  not 
set  in. 

Seances  shemld  not  last  over  five1  minutes  on  the'  average1.  Mild 
cases  usually  receive'!1  in  from  two  to  three'  works— two  1<>  eight  months 
is  not  too  long  for  a  severe  case  to  persist  and  ree-over. 

Tin  Static  Ware  Curnnt  tor  Facial  J'aral;/*/*. —  Win.  Martin'  applies 

1  Amcr.  .Tour.  Electrotherapy  and  Radiology,  vol.  xxxvi.  No.  0,  September, 
lit  is.  P.  '-'.".I. 


171  MKIHCAI.    KLK(  TKHITY    AM)    HO.NTCKN    HAYS 

a  mrtal  electrode  shaped  to  fit  the  side  of  the  face  in  front  and  behind 
t  lie  ear. 

Massey  modifies  this  by  using  the  bull  electrode. 

In  long-standing  intractable  cases  anastomosis  is  useful,  either 
through  the  hypoglossal  or  the  spinal  accessory.  Following  such 
anastomo>is  further  electric  stimulation  is  advantageous. 

t'Ji  In  lixiun*  <>f  the  facial  within  the  a</tn'<luct,  one  may  find  addi- 
tional -yinptom-  due  to  involvement  of  other  structures,  notably  the 
geniculate  ganglion  and  the  chorda  tympani  nerve.  Thus  various 
irregular  herpetic  eruptions,  associated  with  involvement  of  taste  in  the 
anterior  two-third-  of  the  tongue  of  the  affected  side,  and  irregular 
acoustic  symptoms  may  lie  tound.  If  the  symptoms  of  herpes,  facial 
pal.-\  .  loss  of  taste,  and  acoustic  symptoms  are  present,  there  is  un- 
doubtedly true  inflammation  of  the  geniculate  ganglion,  with  direct 
extension  of  the  inflammation  to  the  sheat!'  and  connective  tissues 
of  the  nerve.  In  the  mild  palsies  inflammatory  edema  and  pressure 
are  responsible,  while  in  the  severe  types  inflammation  brings  about 
structural  alterations.  J.  II.  Hunt1  was  the  first  to  show  the  generic 
relat  ion  of  i  he  facial  palsies  \\  it  h  an  herpet  ic  in  (lain  mat  ion  of  t  he  genicu- 
late traiiii'lion.  He  has  described  a  number  of  types  which  are  purely 
of  neurologic  interest . 

Manv  of  these  cases  run  precisely  the  same  course  as  the  more 
di.-tiiicily  peripheral  ones.  Save  for  the  richer  symptomatology, 
they  vary  hut  little  from  the  preceding  group. 

It  is  advisable,  in  treating  these  cases,  to  wait  until  all  symptoms 
of  LM'iiiculate  ganglion  inflammation  have  subsided,  ;md  electric  treat- 
ment is  best  deferred  for  from  two  to  three  weeks. 

(o)  In  facial  jxilxn-x  without  tuxtt'  i7i  rol  rinicnl .  liul  wilfi  loxx  of  hear- 
in;  f.  the  nerve  is  involved  bet  ween  the  geniculate  ganglion  and  the  pons. 
I  hcse  cases  are  not  infrequent  in  cases  of  fracture  of  the  skull,  in  basal 
di.-ease.  and  as  a  result  of  the  herpetic  inflammation  of  the  geniculate. 

'They  are  to  be  treated  in  much  the  same  manner  as  the  preceding 
Lin  nip. 

1  1 1  \\hen  the  /<  sum  is  irif/n/i  the  fion*.  there  is  no  involvement 
of  taste  or  hearing,  but  an  involvement  of  the  sixth  nerve  is  usually 
present  b\  reason  of  the  anatomic  contiguity  of  the  nucleus  of  that 
nerve. 

Klrri  Mi-it  y  i>  of  service  in  these  cases  as  well,  but  does  not ,  as  a  rule, 
Lriv<-  :•.-  hopeful  results.  These  nuclear  lesions  are  usually  syphilitic 
or  met  asvphiht  ic,  in  the  latter  case  often  appearing  very  early  in  tabes 
and  in  general  pa  re-is.  In  these  latter  affections,  naturally,  electric 
tl'eatn  ent  ol  the  facial  ner\'e  is  useless. 

tiiltiti  ml   l-'arial    I'als'i.      This    is    a    rare    affection,    being   due    most 

mien    to    syphilitic    ba>ilar    meningitis,    or    to    alcohol,    diphtheria,    or 

1    edia.       l)ouble    geniculate   affections    have    not    yet    been 

I'lhed,    but    are    possible.       In    certain    mvopathies    a    pseudo-double 

tacial  pal-v  i-  encountered. 

In  '  ol  alcoholic,  ilipht  heric,  or  olitic  origin,  the  general 

proc«-dur<-  advocated  for  unilateral  palsy  are  applicable. 

Vagus    Nerve.      Paralysis  of  the  soft    palate  and    the  larynx   result 

'  '  •    '  IILTUS.      In  paralysis  of  the  sol  t  palat  e  \\\r  react  ion  of 

deirenerat  ion  i~  -ometimes  encountered.  esj)ecially  m  diphtheric  neuritis. 

1  .Inurii:il  I'f  N'-rvMii-  ;,ipl  Mcnt;il  I)i.-c;i-c,  vol.  \\xiv,  p.  7^!.  I''d)rii;iry,  1H07. 


ELECTRICITY    IN    DISEASES    OF   THE    NERVOUS    SYSTEM  475 

In  such  a  condition  electric  treatment  is  of  certain  avail,  particularly 
in  shortening;  the  period  of  regurgitation  of  food  through  the  nose. 

In  paralysis  of  the  vocal  cords  from  recurrent  laryngeal  involvement 
electric  stimulation  is  beneficial. 

Adductor  palsy  is  bilateral;  the  patient  suddenly  loses  the  voice, 
yet  can  talk  in  a  whisper;  there  is  no  stridor,  and  laryngoscopic  ex- 
amination shows  the  cords  to  move  outward  normally. 

Strong  faradic  shocks  often  make  an  immediate  cure  of  hysteric 
aphonia.  (Set'  Hysteria.) 

In  laryngeal  paralysis  due  to  tabes  electric  therapy  is  practically 
unavailing,  nor  is  it  palliative  even  in  laryngeal  crises. 

Spinal  Accessory  Nerve.-  Involvement  of  this  nerve  produces 
change's  in  the  sternomastoid  and  trapc/ius.  causing  the  head  to  be  held 
toward  the  opposite  shoulder,  with  downward  and  outward  displace- 
ment of  the  scapula.  The  scapular  displacement  is  modified  greatly  if 
an  attendant  lesion  of  the  cervical  roots  be  present.  Surgical  lesions 
are  mostly  responsible  for  involvement  of  this  nerve. 

Treatment  is  to  be  carried  out  according  to  the  procedures  already 
outlined  for  paralysis  of  the  facial  nerve. 

Hypoglossal  Nerve. — Paralysis  of  the  hypoglossal  results  in 
hemilingual  atrophy.  This  is  a  comparatively  rani  disorder.  It  may 
be  of  central  or  peripheral  origin,  in  the  former  case  depending  on 
syphilis,  tabes,  or  paresis.  Tumors,  stab  wounds,  basilar  meningitis, 
trauma  with  marked  sudden  rotation  of  the  neck,  may  all  bring  on 
peripheral  palsy. 

There  are  no  particular  features  attending  the  electric  treatment 
of  hypoglossal  palsy.  It  is  rarely  isolated,  as  syphilis  is  the  most  fre- 
quent cause,  in  which  case  it  is  accompanied  by  associated  palsies  of  the 
contiguous  nuclei. 

The  peripheral  cases  frequently  recover  without  any  treatment, 
although  electric  stimulation  hastens  such  a  result. 

Bulbar  Palsies 

As  a  result  of  acute  or  subacute  poliomyelitis,  several  of  the  medullary 
nuclei  may  be  involved.  This  is  particularly  true  in  what  is  known 
as  glossolabial  paralysis,  which  is  a  mixed  paralysis,  involving,  for  the 
most  part,  portions  of  the  nuclei  of  the  seventh  and  twelfth  nerves. 
The  electric  phenomena  observed  in  examinations  in  this  disorder, 
whether  in  the  acute  or  the  chronic  stages,  an^  usually  of  a  mixed 
character.  There  are  healthy  fibers  interspersed  with  unhealthy 
fibers,  the  result  being  that  an  indefinite  reaction  of  degeneration  is 
obtained,  some  of  the  fibers  retaining  the  normal  reaction,  while  ad- 
jacent fibers  present  typic  reaction  of  degeneration.  These  mixed 
reactions  are  found  in  practically  all  the  atrophies,  especially  of  the 
central  type;  that  is.  when  the  motor  cells  in  the  medulla  or  spinal 
cord  are  involved.  They  are  less  often  present  in  the  paralyses  of  a 
peripheral  type,  and,  therefore,  are  of  a  certain  amount  of  diagnostic 
significance. 

The  electric  treatment  of  bulbar  palsy  offers  a  considerable  field 
of  operation.  The  best  results  are  usually  obtained  in  the  distribution 
of  the  seventh  nerve,  although  it  is  not  impossible  to  obtain  SOUK; 
beneficial  results  in  other  nerve  regions. 

It  should  be  borne  in  mind  that   bulbar  palsy  may  be  found  in  a 


47C)  MKIHt  AI.    KLKCTHICITY    AND    K(")NT(iKN    HAYS 

number  of  conditions.  It  in;iy  be  hysteric  or  infantile,  or  it  may  be 
due  to  unknown  ami  unappreciated  pathologic  conditions,  but  its 
ino^t  frequent  occurrence'  is,  as  has  already  been  stated,  in  poliomye- 
litis, in  chronic  progressive  muscular  atrophy,  and  as  a  complication  of 
amyotrophic  lateral  sclen»is. 

Attention  has  already  been  called  to  the  differentiation  of  true 
bulbar  pal-y  from  >o-called  pseudobulbar  palsy,  or  myasthenia  uravis. 
Here  the  inya-theilic  reaction  is  usually  sufficient  to  mark  it. 

It  should  be  borne  in  mind  that  electric  treatment  of  bulbar  palsy 
is  not  without  very  distinct  danger.  The  ordinary  faradic  or  galvanic 
irritat ion.  such  a>  is  practised  in  the  treatment  of  ordinary  paralyses, 
iias  at  times  led  to  di>a>trous  results,  and  even  to  death.  Oppenheim 
has  called  particular  attention  to  this  danger.  Central  galvanization, 
however,  is  of  value. 

The  exact  indications  for  the  electric  tr-atment  of  bulbar  palsy 
an-  not  yet  defined  suitably,  and  up  to  the  present  time  \ve  have  no 
really  reliable  information  hearing  on  the  therapeutic  usa^e  of  other 
forms  of  elect  ric  energy  in  this  affection. 

Paralyses  in  the  Cervical  Region 

As   i-   well    known,    the  spinal   muscular   types  of   paralysis   have   a 

re    which    is   characteristic.      If   the   motor   neuron    is   involved   at 

its  center,  namely,  in  the  iran.ii:! ion-cell  within  the  anterior  horns  of  the 

>pmal  cord,  the  mu-cles  involved  are  usually  affected  from  the  outset. 

They  acquire  the  full  and  maximum  amount  of  paralvsis  very  rapidly, 

and    recovery    i.-   gradual   and  slow.      In   the  peripheral   paralyses.    /.   <., 

when    i  he    motor   neuron    is   affected    through    n>   distal    distribution  — 

apart   from    severance    or    acute    pressure     the    onset     of    paralvsis    is 

usually   slow   and    Liradual.   and    atrophy   becomes   apparent    only   after 

-ome  time.      In  both  tvpes  the  limb,  if  the  whole  member  is  involved. 

-    helples:-      never  stiff.      The  joints  are  relaxed  and  the  articular 

-urfaces    are    u-iiallv    separated    bv    the    weight    of    the    member.      The 

ies   are  flabby   and   relaxed  and  show  little  or  no   myotatic    irrita- 

'    .      The  tendon   reflexes  are  partially  or  wholly   irone.      Their  per- 

-istence  m  the  face  of  a  flaccid  paralvsis  usuallv  means  the  implication 

of  tin  i-ni   |)yramid:il  '  racts. 

Such    lorn  -    »i    paralysis   are   common    m    poliomyelitis,    acute   and 

votroplnc   lateral   sclerosis,    in   tumors   and    hemorrhages 

'•    n    the   i-ord.    m   embolism   or   thrombosis   leading   to   softening,    in 

-••:•_'<-  oi   myelitis,  in  syrin<jfomvelia.  and  in  the  various  forms 

••'    '  '    in*;-.    *    •     i  her  line   to   lend,   alcohol,    mercurv,   arsenic,   diabetes. 

ri'aim'ement s  in  t lie  cells  oi  t he  coi'd  have  already  been 

•  '  •  '  ' '    .   '  •        '    ,   '  •  .-•    I  oca  h /.at  ion  ol    tin-  cell  u.Toiip>  in  the  \\-irious    seu~- 

'   .'   '   '          !',  en    in    t  ;:  hllhi  I1   form.        (See    p.    Ill  I     . 

Functional   or   Organic    Paralyses.      It    remains    first,    in    makintr 
VMS,  eit  her  of  t  he  upper  cervical  t  \  pe  or  of  1  he  lower 
1  •  n  ii  'inipleii'ia  or  paraplegia  i-  pre.-eiit.  to  determine 
i-    is    oriranic    or    functional.     The   differentiation 
niosl    c;ises   comparat  i\'el  v    simple,    yet    in    a    lariz'e 
no  me;ms  an  easv  matter.      Tin-  is  particularly 
':•     early    pal>ies  o|    disseminated   sclerosis,    where 
Aeakness    verv    freoiientlv    simulat<'   a     like     con- 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  477 

dition  ill  hysteria.  As  a  rule,  muscular  atrophy  is  not  an  accom- 
paniment of  functional  disease,  at  least  not  in  the  early  stages,  and  the 
electric  reaction  of  degeneration  never  occurs  in  functional  disorders 
unless  muscular  atrophy  is  found  as  a  result  of  many  years  of  disuse  of 
a  muscle  group.  In  some  of  these  cases  a  reaction  of  degeneration  suffi- 
cient to  raise  a  query  may  be  found.  As  a  rule,  the  functional  paralyse- 
involve  whole  groups  of  muscles,  or  even  whole  muscle  functions. 
Involvement  of  single  muscles  is  usually  diagnostic  of  organic  disturb- 
ance. 

The  differentiation  of  organic  paralysis  in  the  lower  neuron  type, 
that  is.  in  the  spinal  muscular  neuron,  is  a  comparatively  easy  affair, 
since  the  features  already  outlined  are  usually  sufficient  to  develop 
a  definite  diagnosis,  but  in  the  corticospinal  neuron  types,  where  no 
atrophy  is  to  be  expected,  and  where  the  reaction  of  degeneration  does 
not  take  place,  differentiation  becomes  ofttimes  fraught  with  diffi- 
culty. There  are  cases  of  hysteric  hcmiplcgia  and  hysteric  paraplegia 
which  defy  the  ordinary  positive  tests  of  electric  or  neurologic  examina- 
tion. 

In  the  hysteric  hemiplegias  and  paraplegias,  the  study  of  some  of  the 
more  complicated  tendon  reflexes  offers  a  clue  to  diagnosis.  The  re- 
flexes most  often  studied  and  upon  which  most  reliance1  may  bo  placed 
are  those  of  Babinski  and  Oppenheim.  The  Babinxki  reflex  is  almost 
invariably  present  in  the  organic  hemiplegias  and  paraplegias.  The 
Oppenheint  reflex  has  much  the  same  significance  as  the  Babinski 
reflex. 

(rrassct's  sign,  which  is  less  well  known,  consists  in  the  inability 
of  an  organic  hemiplegic  while  lying  flat  upon  the  back  to  lift  both 
the  limbs  from  a  table  or  bed,  but  being  able  to  lift  each  one  sepa- 
rately. The  reason  for  this  is  that  the  organic  hemiplegic,  by  reason  of 
defects  about  the  pelvis,  is  unable  to  fix  the  bones  about  the  pelvic 
girdle,  and  is  thus  unable  to  lift  both  legs  at  one  time.  The  legs  should 
bo  separated  so  that  the  one  cannot  mutually  help  the  other.  The 
hysteric  has  no  difficulty  in  raising  both  logs — i.  c.,  of  course,  speaking 
of  the  milder  typos  of  the  disease  in  both  instances. 

Certain  of  the  more  prominent  paralyses  of  the  cervical  region 
will  be  hero  considered.  The  most  important  of  these  are  the  paralyses 
of  the  trapezius,  sternomastoid,  sorratus  magnus.  scapular  muscles,  and 
deltoid.  Certain  combined  paralyses  of  the  shoulder-girdle,  such  as 
Krb's  palsy,  arc  of  groat  importance, 

Sternomastoid  and  Trapezius. — These  muscles  are  usually  in- 
volved more  or  loss  in  unison,  their  cell  groups  lying  close  to  one  another 
in  the  cord.  When  both  are  involved,  a  central  lesion  is  predicated, 
although  operations  about  the  nock  sometimes  result  in  injury  to  their 
peripheral  nerve-supply.  The  bringing  of  tension  on  the  sternomastoid 
by  forced  rotation  of  the  head  is  usually  sufficient  to  demonstrate  a 
change  in  this  muscle. 

Paralysis  of  the  trapezius  results  in  a  marked  drooping  of  the 
shoulder,  since  this  muscle  is  of  so  much  importance  in  supporting  it. 
The  scapula  is  tilted  with  its  upper  end  away  from  the  median  line 
and  depressed,  the  lower  end  approaching  the  vertebral  column  and 
elevated  somewhat.  On  raising  the  arms  above  the  head  the  outer 
end  of  the  clavicle  becomes  visible  from  behind. 

Electric  treatment   bv  means  of  both  galvanic  and  faradic  shocks 


ITS  MKDICAL    K1.K(  THKTrV    AM)    RONTCiKN    HAYS 

-hould  he  energetic  and  prolonged.  In  surgical  cases  associated  with 
complete  reaction  of  degeneration  in  all  the  libers  of  the  muscle  after 
ten  days  or  two  weeks,  prompt  surgical  splicing  should  he  instituted. 
Kven  after  months  or  years  the1  results  of  surgical  severance  .may  be 
obviated  by  surgical  intervention  combined  with  electric  treatment. 

Serratus  Magnus.  Paralysis  of  this  as  an  isolated  muscle  is  rare, 
though  by  reason  of  the  fact  that  its  nerve-supply  runs  in  the  sub- 
stance of  the  scalenus  medius  muscle  it  may  be  subjected  to  trau- 
ma-, particularly  in  neck  operations.  The  deformity  is  characteristic. 
Kxtension  iif  the  anus  forward  at  right  angles  to  the  axis  of  the  body 
causes  a  marked  winu'  scapula,  the  posterior  edge  appearing  as  a  ridge. 
\\iih  an  attendant  deltoid  paralysis  the  inability  to  extend  the  arms 
forward  makes  it  impossible  to  bring  out  the  phenomenon. 

In  testing  fur  this  paralysis  Jones  recommends  that  the  indifferent 
electrode  be  placed  in  the  posterior  triangle  of  the  neck  and  the  active 
electrode  applied  to  1  he  serrations  of  the  muscle. 

In  paralysis  of  this  nerve  as  a  result  of  infection  or  pressure  (as 
seen  in  some  special  occupations — poling  boats  etc.).  electric  treatment 
is  Very  effect  ive. 

Supraspinatus  and  Infraspinatus.  In  paralyses  of  these  muscles 
extern.-d  rotation  of  the  luimerus  becomes  an  awkward  affair:  writing 
becomes  ditiicult.  and  the  ordinary  sewing  movements  ot  pushing  a 
needle  in  and  taking  i'  out  of  a  fabric  are  impossible.  Atrophy  of  the 
muscles  causes  a  ridge  of  the  scapula  to  stand  out  prominently.  As  the 
supraspinatus  lies  dee])  beneath  the  trape/ius.  electric  reactions  are 
;::;:>-ult  to  obtain.  In  obstetric  paralysis  the  suprascapular  nerve, 
uhich  -npplies  the  -pinati.  may  be  involved  in  conjunction  with  the 
circumflex. 

Klei-tric  treatment  for  these  paralyses  differs  in  no  essential  par- 
t  ic  liars  from  1  hat  in  ot  her  parts  of  t  he  body. 

Deltoid    Paralysis.     The  circumflex,  derived  from  the  fifth,  sixth, 

seventh,  and  eighth  cervical   nerves,  supplies  the  deltoid  and  the  teres 

Inability  to  raise  the  arm  is  the  chief  siirn  in  deltoid  paralysis. 

iliscle    wastes   and    the  shoulder   flattens.      The   acromion   process 

becomes  more  prominent,  the  humerus  at  limes  hanging  away  from  the 

joint. 

Paralysis  oi   the  deltoid  may  be  partial  or  complete,  and  cases  are 

record,  e.Mction    of    degeneration    in    parts    of    the    muscle,    other 

normal   reactions.      These  isolated   paralyse-   result    from 

More   particularly    blows,    trauma    from    axillarv    pads. 

•j  on  the  arm  at   birth      may  all  involve  the  circumflex, 

•  •  •    •  .•  •     ,-     .  .':  ich  nives  ii   origin. 

'•    rni'j  of  the  teres  ininor  is  difficult   to  carry  out.      Testing 

-at  isfacl '  irv. 

I'    r;d  •     the    (jelioid     i-    UHlallv    an    obstinate    affair.       Klectric 

\ci    lent    results,    but    i  he-e    i>    ffe<  |  iient  iv    a    residual 

!>  foi    vears  all  at  tempts  at   rest  it  in  ion. 

Combined     Palsies.     The    combined    palsies  due   to    trunk    lesions 

iied    from    those    \\hicii    io||o\\    a    legion    of    the    roots 

/-.'  •//,     /i'il.-  .  .      \  )i-|i  ical  ions    of    i  he    -In  mlder- 

•     head   of   the    humerus   should    press    forward. 

i;i'-pre;id   and   -erion-    paralyses    involving  one  or 

•Li    brachial    plexus.      A  diagnosis   of   the  nerves 

•  p  •     :  '•  :  a  I  v/ed   mu-cles. 


ELECTRICITY    IN    DISEASES    OF    THE    XEKVOUS    .SYSTEM  479 

Reaction  of  degeneration  soon  develops  in  ihose  muscles  most 
implicated,  especially  after  the  period  passes  when  a  stage  of  inter- 
stitial edema  is  apt  to  cause  hard  and  stiff  muscles,  for  in  such  a  con- 
dition reaction  of  degeneration  is  difficult  to  obtain.  In  many  cases 
of  neuritis  which  may  cause  extensive  atrophies  the  presence'  of  severe 
pain  may  interfere  with  electric  and  testing  electric  treatment  for  some 
time. 

Erb's  Paralysis. — This  consists  essentially  in  a  lesion  of  the  roots 
of  the  brachial  plexus,  due  to  a  severance  or  tearing  of  the  root-fibers 
as  they  emerge  from  the  spinal  cord.  As  a  rule,  the  chief  damage  is 
done  to  the  fifth  and  sixth  cervical  nerves,  although  only  the  fifth, 
or  only  the  sixth,  or  even  the  seventh,  may  be  disturbed,  and  the  mus- 
cles most  widely  implicated  are  the  deltoid,  biceps,  supinator  brevis, 
brachialis  anticus,  and  the  spinati.  At  times  only  the  deltoid  is  in- 
volved. There  may  be  associated  anesthesia  on  the  outer  aspect  of 
the  arm,  due  to  the  implication  of  the  external  cutaneous. 

The  position  of  the  arm  in  Erb's  obstetric  palx;/,  called  obstetric 
because  so  frequently  induced  as  an  obstetric  accident — pulling  of  the 
arm  in  delivery  with  stretching  and  tearing  of  nerve-roots — is  very 
characteristic,  ('specially  if  more  than  a  mere  paralysis  of  a  few  fibers 
of  the  deltoid  is  present.  The  arm  usually  hangs  helpless  by  the  side, 
the  forearm  being  turned  inward  and  backward,  so  that  the  palm  of  the 
hand  is  turned  backward  and  even  outward. 

The  electric  reactions  are  of  interest  in  showing  the  distribution  of 
the  implicated  fibers,  since  the  biceps,  coracobrachialis.  and  brachialis 
anticus  are  supplied  by  the  musculocutaneous,  the  deltoid  is  supplied 
by  the  circumflex,  the  supinator  longus  is  supplied  by  the  musculo- 
spiral,  and  the  spinati  by  the  suprascapular  nerve.  In  traumatic 
affections  of  the  musculospiral,  and  in  the  neuritides,  particularly  that 
of  lead,  the  supinator  longus  escapes,  since1  the  spinal-cord  cell-group 
fibers  enter  the  plexus  above  the  point  of  fusion  that  makes  up  the 
musculospiral  nerve. 

Electric  testing  at  Flrb's  point — i.  c.,  in  the  neck,  about  one  inch 
above  the  clavicle,  and  a  trifle  external  to  the  outer  border  of  the  sterno- 
cleidomastoid,  is  capable  of  throwing  this  entire  group  of  muscles  into 
activity,  and  when  obstetric  palsy  is  present,  stimulation  at  this  point 
is  unavailing.  In  Erb's  palsy,  also  called  Duchenne-Erb  palsy,  other 
muscles  may  be  involved,  and  a  great  degree  of  complexity  is  known  to 
occur. 

The  electric  treatment  of  Erb's  palsy  by  means  of  both  galvanic 
and  faradic  currents  should  be  continued  for  a  long  time;  many  mild 
cases  recover  spontaneously  without  treatment,  but  in  the  severer  cases 
electric  stimulation  is  of  immense  service. 

Injury  to  brachial  plexus,  as  by  dislocation  of  the  shoulder.  W. 
Mart  in1  tests  by  static  wave  current,  plexus  and  ent  ire  length  of  branches, 
and  treats  by  wave  current,  high-frequency  static  sparks,  radiant 
heat  and  light. 

Musculospiral  Paralysis. — This  nerve  i-  most  frequently  involved 
outside  oi  the  plexus,  and  causes  a  lo.-s  of  power  in  the  extensor.-  of 
the  forearm  and  wrist  and  the  supinators.  The  wrist  drops,  the  finuvrs 
are  flexed  but  can  be  extended,  if  the  proximal  joint  is  flexed,  by  the 
interossei  and  the  lumbricales.  Extension  of  the  elbow  is  impossible; 

1  AMHT.  Jour.  Electrotherapy  ;iml  K;t<lio!<>uy,  vol.  xxxvi,  No.  1,  p.  2.1. 


IM)  MKDK    \L    KLK<  TKK  ITY    AM)    ROXTGEN    KAYS 

atrophy  of  the  extensors  causes  the  forearm  to  shrink  very  materially, 
while  t  he  bone-  of  t  he  wrist  become  very  apparent .  Involvement  of  the 
biceps  points  to  mjiirv  above  the  middle  of  the  arm.  and  supination 
i-  then  moderately  well  performed.  If  supination  is  entirely  .u'ono,  the 
nerve  is  usually  implicated  below  the  middle  of  the  arm.  Sensory  dis- 
t  urbaiices  are  frequent . 

I  he  commonest  cause  of  musculospiral  paralysis  is  pressure  duo 
to  -leepim:  on  the  arm.  or  with  the  arms  hunting  over  t  ho  back  of  a 
chair,  or  poor  adjustment  of  a  crutch. 

Reaction  of  degeneration  in  the  various  muscle-  innervated  by 
the  musculospiral  L-  sufficient  to  make  a  diagnosis  of  this  palsy,  and 
TO  distinguish  it  from  the  wider  implications  of  the  brachial  plexus 
in  Krb's  palsy. 

Treatment   of  musculospiral  paralysis  by  the  iaradic  and  galvanic 
current.-   i-  of   iM'eat    service,  save   in  those  c.-ses   where  actual   section' 
of    the    nerve    has    taken    place.      The    electric    currents    are    of  service 
after  the  nerve  has  been  united  by  suture. 

Median  Nerve.  The  median  supplies  the  pronators.  the  flexor 
carpi  radialis.  the  flexor-  of  the  tinkers,  and  the  abductors  and  flexors 
of  the  thumb,  and  the  1  wo  radial  lumbricales.  which  flex  t  he  first  phalanx- 
It  arises  from  all  the  roots  of  the  brachial  plexus.  This  nerve  may 
be  involved  above  its  muscular  branches  from  wounds  in  the  forearm, 
fracture  of  the  ulna  and  radius,  injury  at  the  back  of  the  elbow,  from 
pre-.-ui'e  of  a  crutch,  or  from  injury  to  parts  of  the  plexus.  Plexus 
injuries  will  not  irive  isolated  median-nerve  involvement. 

The  chief  symptoms  of  involvement  of  the  median  nerve  consist 
in  the  lo>-  of  ability  to  flex  and  to  pronate  the  forearm;  this  latter  is  a 
relative  rather  than  an  absolute  loss.  Flexion  to  the  ulnar  side  of 
the  wriM  is  po.--ible.  The  hand  cannot  irrasp  anything  well,  and  the 
thumb  cannot  be  brought  into  apposition  with  the  tips  of  the  finders. 
It  cannot  be  abducted  either.  Pain  is  a  frequent  symptom,  and  there 
is  a  characteristic  anesthesia  pictured  in  \\orks  on  neurology. 

Injuries  to  I  he  nerve  in  the  wrist  causes  a  paralysis,  limited  to 
i  h(  movements  of  the  finders.  Atrophy  ot  the  thenar  eminences  is 

1  he  median  nerve  is  frequently  affected  by  toxic  agents,  with  result- 

euritis,  although  this  is  rarely  isolated. 

Treatment     of    paralvsis    from    median-nerve    neuritis,    or    of    that 

dui    to   injury  of  the  nerve-trunk,  by  mean-  of  electric  currents  differs 

no  (•--•  -mial  re- pec  t   from  the  methods  to  be  pursued  for  other  nouri- 

tide-   oi    paralvsos.       If  electric   testing  shows   the   reaction   of  deuenera- 

t  ion  l  o  be  limit  ed  to  !  he  (list  rib  lit  ion  ot   the  median,  it   is  hlii'hl  v  probable 

'   the  injun    i-  ([ue  to  Mime  mechanic  cause. 

Ulnar   Nerve.      This    is    derived    from   the  brachial    plexus,   and   is 

io    the    flexor    profundus    dimtorum.    flexor    carpi    ulnaris,    all 

oi    the   little   finder,    the   mtero.-sei.    two   ulnar  lumbricales, 

nd  the  flexor  brevis   polbcis.      Manv  of  the  muscles 

'.'.•    :.  upplied   in   part    bv  other  nerves,   hence  there  is  not   a 

\    characteristic  deformity,    the  claw    hand,    is   a    usual 

,->is.      The  deformity  i-  '_;eneral.  but    the  third  and 

'    affected. 

I  he    ulnar   IM:         i-    particularly   e.xpo-ed    to   damage   bv    reason   of 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  481 

its  exposed  position.  Wounds  in  the  forearm,  at  the  wrist,  fracture  of 
the  ulnar  or  radius,  dislocation,  fractures  or  contusions  at  the  elbow, 
all  may  lead  to  injury  of  this  nerve.  Isolated  neuritis  is  known. 

Head,  Rivers,  and  Sherrington  have  shown  that  the  ulnar  nerve 
carries  epicritic  fibers  of  touch  to  one  and  a  half  finders,  and  the  ulnar 
portion  of  the  palm  and  dorsuni  of  the  hand.  It  carries  sensation  of 
pricking  from  the  little  and  ring  finders  and  the  palm,  save  from  the 
thenar  eminence,  and  all  the  dorsuni  to  the  ulnar  side  of  the  middle  of 
the  middle  finder.  If  the  nerve  be  divided,  there  is  loss  of  sensibility  to 
cotton- wool  over  the  entire  little  finder  and  half  of  the  ring  finger,  with 
the  same  limited  area  in  the  palm  of  the  hand.  There  is  also  an  area 
which  is  insensitive  to  pin-prick  over  the  entire  little  finger,  and  a  por- 
tion of  the  palm  at  times  very  limited,  at  other  times  coextensive  with 
the  area  lost  to  light  touch. 

Spinal  Motor  Centers  and  Motor  Nerves  of  the  Lower  Extremity 

These  are  less  often  involved  in  injuries  than  are  those  of  the  upper 
limbs,  whereas  the  gray  matter  in  the  cord  is  more  apt  to  be  the  seat  of 
disease  than  in  the  cervical  region.  In  acute  poliomyelitis  the  muscles 
of  the  lower  limbs  are  usually  affected  more  than  those  of  the  upper 
extremity,  this  being  particularly  true  of  the  peronei.  A  short  consider- 
ation will  be  given  to  the  chief  paralyses  of  the  thigh  and  leg.  Their 
treatment  may  be  considered  in  one  paragraph. 

Obturator  Nerve. — This  is  derived  from  the  third  and  fourth 
lumbar  nerves,  and  supplies  the  adductors  of  the  thigh.  It  is  a  rare 
form  of  palsy,  chiefly  causing  difficulty  in  crossing  one  leg  over  the  other 
and  in  spreading  the  legs  apart.  The  disorder  is  known  to  follow 
difficult  child-birth,  but  is  usually  a  transitory  affection. 

Anterior  Crural. — Disease  or  injury  to  this  nerve  in  different 
parts  of  its  course,  if  within  the  pelvis,  may  give  rise  to  loss  of  power 
to  flex  the  knee  and  loss  of  hip  flexion.  If  outside  of  the  pelvis,  flexion 
of  the  knee  alone  is  involved.  An  anesthesia  of  the  entire  thigh,  save  a 
long  V-shaped  area  in  the  back  of  the  thigh,  is  present  as  well. 

Sciatic  Nerve. — If  this  nerve  is  involved  above  the  middle  third 
of  the  thigh,  the  flexors  of  the  knee,  the  extensors  of  the  hip,  and 
all  the  muscles  below  the  knee  are  implicated.  If  below  the  upper  third, 
only  the  muscles  below  the  knee  are  involved.  Paralysis  of  the  sciatic 
is  a  comparatively  rare  affection.  Sensory  disturbances  are,  however, 
very  common,  and  primary  neuritis  or  sciatica  is  one  of  the  commonest 
of  neuralgic  or  neuritic  affections. 

Peroneal  Paralysis. — Involvement  of  the  external  and  internal 
popliteal  nerves  causes  great  loss  of  the  ability  to  get  about.  The 
tibialis  anticus.  long  and  short  extensors  of  tin'  toes,  and  the  peronei 
are  all  involved  in  external  popliteal  injuries.  The  resulting  deformity 
is  foot-drop,  with  after-developing  talipes  equinus.  due  to  the  unop- 
posed action  of  the  gastrocnemius.  As  the  external  popliteal  is  super- 
ficially located  it  is  injured  by  pressure,  by  fractures  of  the  fibula,  and  is 
occasionally  diseased  primarily. 

The  internal  popliteal  supplies  the  tibialis  posticus  and  poplitetis, 
as  well  as  the  chief  muscles  of  the  back  of  the  leg.  the  long  flexors  of 
the  toes,  and  the  muscles  of  the  sole  of  the  foot.  In  injury  or  disease  of 
31 


482  MEDICAL    ELECTRICITY    AND    ROXTGEN    RAYS 

this  nerve  the  foot  cannot  bo  extended,  and  tho  leg  cannot  bo  inwardly 
rotated  when  flcxod  if  tho  poplitous  is  affected.  Injury  of  the  internal 
popliteal  takes  place  in  extensive  fractures  of  both  bones  of  the  leg. 

Plantar  Paralysis.— Involvement  of  the  external  plantar  nerve 
causes  a  loss  of  power  in  tho  interossei,  the  adductor  of  the  big  toe, 
tho  two  outer  lumbricales.  and  the  accessory  flexor  of  the  foot.  Walking 
is  interfered  with,  the  spring  having  departed  from  the  foot.  The  toe 
is  apt  to  strike,  and  stumbling  is  usual.  The  special  sensory  area  is 
sharply  limited. 

Injury  to  the  internal  plantar  nerve  brings  about  a  paralysis  of 
the  short  flexors  of  the  toes,  the  muscles  of  the  big  toe,  save  the  adductor, 
and  the  inner  lumbricales.  It  causes  a  somewhat  similar,  although 
much  less  marked,  difficulty  in  walking. 

Treatment. — The  electric  treatment  of  these  palsies  differs  in  no 
essential  respects  from  that  already  outlined  in  previous  paragraphs. 
In  general,  one  can  derive  considerable  assistance,  so  far  as  prognosis 
is  concerned,  from  the  electric  reactions.  The  degree  of  degeneration 
which  has  occurred  can  bo  determined,  and  also  the  probable  length 
of  time  necessary  for  recovery.  In  all  these  paralyses,  of  the  lower  as 
well  as  the  upper  extremities,  the  same  general  rule  must  be  followed 
as  that  already  outlined.  It  is  necessary  in  all  cases  to  wait  ten  days 
to  two  weeks  for  the  sake  of  a  diagnosis,  as  well  as  a  prognosis.  In 
the  case  of  patients  where  neuritis  is  found,  or  in  whom  painful  nerve- 
trunks  may  be  present  apart  from  neuritis,  such  as  may  be  due  to  the 
irritation  of  the  moninges,  too  early  electric  treatment,  or  even  the  use 
of  electricity  for  diagnostic  purposes,  should  be  deprecated  by  reason 
of  the  extreme  pain  which  may  bo  induced.  If  pain  be  not  a  prominent 
feature,  the  electric  reactions  should  be  tested  as  early  as  the  second 
week;  any  earlier  is  valueless,  so  far  as  diagnosis  is  concerned.  In 
general  it  may  be  said  that  if,  at  the  end  of  from  two  to  three  weeks, 
we  obtain  a  typic  reaction  of  degeneration,  it  is  probable  that  the 
paralysis  will  persist  for  at  least  three  months,  and  may  oven  be  found 
at  a  much  later  date — a  year  or  so.  If,  after  three  months,  no  distinct 
improvement  has  been  observed,  it  has  been  generally  held  that  no 
hopeful  outlook  can  be  maintained.  This,  however,  is  not  the  case, 
for  continued  and  unremitting  attention  paid  to  the  chronic  paralysis 
will  almost  invariably  result  in  the  restoration  of  considerable  power, 
at  least,  and  the  general  rule  that  if  reaction  of  degeneration  is  present 
in  a  muscle  at  the  end  of  three  months  such  muscle  is  doomed,  is  in 
need  of  distinct  revision.  This  may  oven  be  said  of  those  reactions  of 
degeneration  which  are  found  in  paralyzed  groups,  even  after  a  year, 
although  m  such  cases  the  outlook  is  more  gloomy. 

If  a  partial  reaction  of  degeneration  is  found,  or  mixed  reaction, 
'})<•  chances  are  much  better,  and  if  in  the  milder  cases  of  neuritis  or 

ipheral  pal^y  due  to  injury  other  than  actual  division  of  the  norvo, 
reaction  of  degeneration  occurs,  the  patient  will  probably 
uer  in  ;rom  eight  to  ten  weeks. 

reaction  is  simply  one  of  a  lessened  contractility  to  faradism 
f    recovery  are  good,   the  patient    usually 
-omewhat    diminished    in    strength, 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  483 

the  lower  limbs  have  already  been  outlined  and  are  further  discussed  in 
the  paragraphs  on  Electromcchanotherapy. 

All  electric  treatment  should,  if  possible,  be  associated  with  massage 
and  exercises. 

Hysteric  Paralysis 

Faradic  currents  are  used  to  cause  contraction,  while  at  the  same 
time  the  patient  makes  a  voluntary  effort.  This  forms  a  sort  of  re- 
education. Sensory  hysteric  paralysis  always  yields  to  faradism,  with 
rapid  interruptions  and  a  brush  electrode.  Hysteric  amaurosis  or  more 
or  less  contraction  of  the  field  of  vision  are  treated  by  faradization 
with  one  of  the  electrodes  applied  to  the  eyelids.  Hysteric  aphonia 
is  treated  by  faradism,  and  usually  is  quickly  cured,  though  one  case 
of  the  author's  resisted  all  kinds  of  treatment,  including  hypnotic  sug- 
gestion. Hysteric  vomiting  is  treated  by  galvanic  currents. 

Hysteric  Contractures. — Faradization  with  a  brush-electrode  ap- 
plied either  to  the  contracted  muscle  or  to  its  antagonist,  and  galvanic 
current  with  the  negative  electrode  applied  to  the  contracted  muscle, 
bring  about  a  cure. 

ELECTROMECHANOTHERAPY 

This  means  the  application  of  electricity  to  produce  muscular 
contraction.  It  is  useful  when,  for  any  reason,  it  is  impossible  or 
undesirable  for  the  patient  to  exercise  his  muscles,  any  particular 
muscle,  or  any  part  of  a  muscle. 

It  has,  to  a  greater  or  less  extent,  the  same  beneficial  effect  upon 
the  nutrition  of  the  muscle  and  upon  the  general  system  that  natural 
exercise  produces.  Muscular  contraction  is  accompanied  by  oxidation, 
generation  of  heat,  and  complex  processes  of  tissue  activity. 

It  must  be  borne  in  mind  that  electricity  has  a  specific  tonic  effect 
upon  muscular  as  well  as  other  tissues,  which  it  exerts  whether  mus- 
cular contraction  is  produced  or  not.  This  direct  effect  is  more  de- 
pendent upon  the  quantity  of  electricity  passed  through  the  muscle 
than  upon  abruptness  in  the  change  in  the  strength  of  the  current.  The 
direct  effect  upon  the  nutrition  of  the  muscles  is  produced  chiefly 
by  galvanic  and  sinusoidal  currents,  and  is  obtained  by  forms  of  ap- 
plication which  do  not  necessarily  produce  muscular  contraction,  and 
also  in  cases  of  degeneration  in  which  no  contraction  can  be  produced 
by  any  form  of  current. 

Confining  attention  strictly  to  eletromechanotherapy  (the  therapeu- 
tic production  of  muscular  contraction  by  electric  stimulation),  we  find 
it  indicated  in  most  muscular  paralyses  without  marked  reaction  of 
degeneration.  It  is  sometimes  important  to  avoid  stimulation  of  the 
antagonistic  muscles  which  respond  more  readily  than  the  paralyzed 
ones,  and  would  lead  to  increased  deformity.  If  this  occurs  from  uni- 
polar stimulation  with  the  indifferent  electrode  upon  the  back,  it  may 
often  be  prevented  by  placing  both  electrodes  on  the  paraly/ed  muscle. 

The  limb  should  be  placed  in  such  a  position  that  contraction  of 
the  muscle  stimulated  will  produce  a  normal  movement. 

\  ery  often  some  power  of  voluntary  movement  is  present,  and  it  is 


-1S4  MEDICAL    KLKCTKK  ITY    AM)    KO.NTGKN    HAYS 

desirable  to  apply  electric  stimulation  to  assist  individual  attempts 
at  voluntary  movement . 

As  improvement  takes  place  the  factor  of  movement  against  resist- 
ance is  to  be  introduced,  making  the  effect  still  more  like  the  physiologic 
effect. 

Too  lonii  treatments  will  produce  fatigue  in  the  same  way  as  too 
prolonged  natural  exercise.  Thi>  is  to  he  avoided. 

Method  for  r.fv/r/Wm/  i><ir(tli/:'«l  ///f/.sr/r.s  hij  tfic  xiat/c  induced  current 
is  descril KM!  on  page  ~i\'.\. 

The  faradic  current  is  suited  chiefly  to  stimulation  of  the  motor 
nerve,  and  the  galvanic  to  stimulation  of  the  muscle  in  case  the  nerve 
lias  lost  its  excitability. 

Stimulation  by  galvanic  currents  is  excellent  in  its  trophic  or 
tonic  and  nutritional  effect,  and  with  moderately  strong  uninterrupted 


\J 


2.  Direct 
Yaro 


isft'<   ffofroao-fargc/tc. 


currents,  1")  ma.,  has  an  excellent  effect  without  causing  muscular 
contraction.  To  produce  the  latter  the  galvanic  current  must  he  made 
and  broken  and  should  be  much  weaker,  to  prevent  discomfort.  This 
involves  t  lie  loss  of  sonic  of  I  he  benefit  obtained  from  1  he  t  rophic  act  ion 
of  i  he  current . 

<  ialvanic  currents  are  usually  applied  so  as  to  How  with  the  phys- 
iologic direction  oi  the  nerve  force.  !•  oi-  I  he  treatment  of  the  motor 
nerve-  or  « >f  I  he  muscles  t  he  posit  ive  elect  rode  should  be  near  1  he  nerve- 
cenliT.  and  tin-  negative  electrode  should  be  applied  to  the  motor  nerve 
or  to  the  mu-'  1,  . 

Galvanic  Currents  Modified  by  Condensers  in  Parallel.-  These  are 
a  valuable  in  \\  tne;ms  of  applying  a  ii-elul  strength  of  current  without 
prodiicinu:  unnalurallv  abrupt  muscular  contraction.-  (paue  Mil). 

Stimulation  by  isolated  induction  shocks  produce-  abrupt  muscu- 
lar contraction-,  which  are  1  >et  ter  t  han  none,  but  which  are  less  desirable 


ELECTRICITY     IN    DISEASES    OF    THE    NERVOUS    SYSTEM  485 

than  if  they  approached  the  physiologic  type.  It  -rives  HOIK;  of  the 
direct  tonic  effect  of  electricity,  because  the  quantity  of  electricity 
which  passes  through  the  muscle  is  very  snuill. 

Stimulation  by  condenser  discharges  is  open  to  the  same  objection 
from  a  therapeutic  standpoint,  though  the  certainty  with  which  each 
discharge  may  be  measured  makes  it  a  valuable  diagnostic  method. 

Faradization  is  the  method  chiefly  employed  for  elect romeclmno- 
therapy,  but  it  has  the  same  drawbacks  as  isolated  induction  discharges 
and  condenser  discharges.  The  contractions  produced  by  it  are  not  as 
desirable  as  physiologic  contractions,  and  the  quantity  of  electricity 
is  too  small  to  produce  the  direct  tonic  effect  of  the  current.  If  the 
faradic  current  is  employed,  it  had  better  be  applied  with  one  electrode 
on  the  motor  nerve  or  the  motor  point  of  the  muscle,  while  the  other 
electrode  is  on  the  back  or  chest  or  some  other  indifferent  place1,  and  the 
application  be  made1  simply  to  cause  muscular  contractions,  being  sup- 
plemented by  the  galvanic  current  for  its  trophic  effect. 

The  combined  effects  of  faradic  and  galvanic  currents  may  be  ob- 
tained by  either  their  simultaneous  or  their  successive  application.  The 
second  method  is  one  by  which  galvanic  currents  of  any  desirable 
strength  are  applied  for  ten  minutes  from  electrodes  covering  the  whole 
affected  muscle,  either  before  or  after  a  series  of  muscular  contractions 
have1  been  excited  by  the  faradic  current. 

Lewis  Jones'  experiments  show  that  a  faradic  coil  without  an  iron 
core  gives  currents  without  such  abrupt  increase1  and  decrease  in  strength 
and  produces  less  abrupt  and  disagreeable  muscular  contractions  than 
when  the  coil  has  an  iron  core.  Kven  so  modified,  however,  the  faradic 
coil  produces  quite  an  abrupt  beginning  and  end  of  muscular  contraction, 
with  a  period  of  tetanus  lasting  from  the  time  the  current  is  turned 
on  until  it  is  turned  off.  This  is  not  at  al!  like  the  physiologic  con- 
traction, and  is,  therefore,  less  desirable  than  the  contraction  produced 
by  the  author's  method  of  rhythmic  variation  by  rheostat  and  pole- 
changer,  or  by  the  other  method  of  sinusoidal  currents  with  rhythmic 
variation. 

Faradogalvanic  or  deWatteville  currents  are  applied  from  an 
apparatus  in  which  the  secondary  coil  of  a  faradic  coil  forms  part  ot 
the  circuit  of  a  galvanic  battery.  "While  it  has  been  stated  elsewhere 
that  the  polarity  of  a  faradic  coil  makes  practically  no  difference  in  the 
physiologic  effects,  and  that  either  pole  may  be  used  as  the  active 
electrode,  this  ceases  to  be  true  when  the  faradu-  and  galvanic  currents 
are  combined. 

Figure1  -$10,  1 ,  shows  the1  form  of  the  interrupted  currents  produced  by 
a  faradic  coil  alone1.  The1  make  or  closure1  e-unvnt  is  of  much  less 
-tretiglh  and  is  in  the1  e>pposite  direction  from  the1  ctinvnt  induceel 
at  the1  break  or  opening  of  the1  primary  circuit.  The1  best  results  are1 
obtained  with  a  galvanofaradic  current. 
made  so  that  the1  opeMiing  currents  of  the 
direction  as,  and  add  to  the  strength 
proper  effect  is  shown  in  Fiii'.  olO,  2,  and 
in  Fig.  MIO,  :i. 

The  sensation  produced  by  galvanofaradi/at ion  is  different  from 
that  of  e'itluM1  of  the1  component  cunvnts  separately.  Its  eftVct  is  to 
cause  muscular  contraction  ami  trophic  stimulation,  but  applied  in 


4M>  MKDICAL    ELKCTUICITY    AXI)    KOXTCKX    KAYS 

the  ordinary  way  by  means  of  a  key  that  makes  and  breaks  the  current 
abruptly  the  muscular  contractions  have  the  same  unnatural  character 
as  with  the  Dimple  faradic  current. 

The  <i><tln>r'«  nni/n»!  of  applying  faradoyalvanic  current*  produces 
muscular  contractions  which  closely  resemble  physiologic  ones,  and 
make-  the  application  agreeable,  and  causes  it  to  be  followed  by  a  sense 
of  muscular  power  which  is  most  exhilarating  and  beneficial.  It  con- 


E 


1  1.       \iitlini1'-  nalvanii-,  faradir.  and  sinusoidal  apparatus-  piving  also  galvano- 


urrent-,  and  currents;  with  rhythmic  variations 


si-t.-  in   ihi'  u-e  ot    a   i'/i i/lli in ic  rficoxltit  on/]  polc-cha/if/cr  i  Fiii.  311,  A), 

ilireciion  of  the  current  i.-  reversed  at  regular  intervals  of 

from    one-hall    -ecoiid    to    two    seconds.       There    are    sliding    contacts, 

•  •    ;   up  and  down  the  rheostat   liy  n  small  electric  motor. 

At   a  certain  -•;  •_;<•  the  Lialvanometer  \\'ill  show  thai   no  current   is  passing 

ihioii-i:  ti.t-  p;  • ;.  in.     '1'hcii.  as  'he  rheostat   ix'sistance  is  automatically 

ri-duccd,  liii'  c  .  rent    gradually  lieuin^  io  llo\\'  in  one  direction,  and  in- 

.':;.   I  ")  ma.,  [lerhajts,  permitte(|  by  the  adjustment 

11!  anoil  •        •  in'j  rheo-tat  and  the  unvai'yin.u  \'olt  coni  roll<-r.      The 

liet  tei'  l>e  made  al  t  he  commencetiient  ot  t  lu1  treat- 
iiierii .      I  •    •        r.     ,    it  iV  j  M\>t  to  beiiin  wit  h  t  he  weakest  possible  current. 
\-arym.i:   rhen-tal    ha>   permitted   the  maximum 
low.  the  current    i-  lii'aduallv  reduced  to  zero,  and  is 

: '     •  ,  ia  itains  an  eijiial   maximum  strength  in  the  op- 

tio-iti         •  ••  In  re  n   auain  ii'raduallv  return.-  to  zero. 


ELECTRICITY    IN    DISEASES    Or    THE    NERVOUS    SYSTEM  487 

Holding  two  electrodes  in  the  hands,  one  feels  his  grip  gradually 
tighten  and  'relax,  first  in  one  hand,  and  then  in  the  other,  as  the  maxi- 
mum current  is  attained  in  each  direction.  All  the  muscles  of  each 
upper  extremity  are  affected  by  the  trophic  influence  of  the  galvanic 
current,  and  the  muscular  contraction  may  be  caused  to  involve  as 
man\-  of  these  muscles  as  desired  by  regulating  the  strength  of  the  faradic 
current.  The  application  is  entirely  free  from  shock  and  other  dis- 
agreeable sensations.  Its  alternating  character  prevents  irritation  of 
the  skin  by  the  accumulation  of  ions,  and  enables  one  to  secure  the  bene- 
ficial effects  of  strong  currents  without  having  to  use  enormous  electrodes. 
A  good  contact  is  the  chief  essential.  The  contractions  closely  simu- 
late physiologic  ones. 

These  currents  are  of  great  value  in  peripheral  paralyses  and  in 
constipation,  where  the  electrodes  are  applied  at  either  side  of  the  ab- 
domen. 

The  same  picture  (Fig.  311)  shows  also  the  arrangement  for  utilizing 
the  1  10-volt  direct  current  in  galvanic,  faradic,  and  deWatteville  appli- 
cations, continuous  or  interrupted. 

In  the  author's  apparatus  there  are  three  different  secondary  wind- 
ings of  the  same  faradic  coil,  made  instantly  available  by  turning  a 
switch  indicating  loOO,  3000,  or  8000  feet  of  wire.  The  ribbon  vi- 
brating interrupters  regulate  the  rapidity  of  the  interruptions  from  the 
fastest  to  the  slowest,  and  the  two  separate  primary  coils  may  have 
the  same  or  different  rates  of  vibration.  There  is  a  sledge  upon  which 
the  single  secondary  coil  may  be  moved  toward  or  away  from  the  pri- 
mary coils.  The  farther  away  the  weaker  the  current  and  the  physi- 
ologic effect. 

Gaiffe's  Portable  Apparatus  for  Exciting  Physiologic  Contrac- 
tions of  Muscles. — The  apparatus  is  useful  in  cases  where  paralyzed 
or  atrophic  muscle's  are  to  be  exercised  in  order  to  maintain  their  nutri- 
tion, but  not  in  cases  with  the  reaction  of  degeneration.  Faradic  cur- 
rents cause  muscular  contractions  which  are  unnatural  in  the  abrupt- 
ness with  which  they  begin  and  end.  Voluntary  muscular  contractions 
commence  gradually,  and  after  attaining  their  maximum,  gradually 
relax.  The  apparatus  described  by  Delherm1  produces  contractions  of 
this  type  by  the  application  of  a  sinusoidal  current,  which  increases  from 
zero  to  a  maximum  strength,  and  then  gradually  diminishes  to  zero. 
The  apparatus  consists  essentially  of  an  electromagnet  which  oscillates 
in  front  of  a  dynamo,  and  causes  increasing  or  diminishing  currents  in 
the  latter.  It  is  portable.  Figure1  312,  from  Delherm.  shows  the  current 
curve  and  the  wave  of  muscular  contractions  obtained  with  this  appa- 
ratus. Figure  313  shows  the  current  curve  with  isolated  induction  shocks 
from  a  faradic  coil  and  the  waves  of  muscular  contractions  produced  by 
them.  Figure  314  shows  the  current  wave  from  the  usual  faradic  cur- 
rent and  the  tetanic  muscular  contraction  produced  by  it. 

Lcdnc  current*  are  currents  which  are  uniform  and  unidirectional, 
but  which  are  made  and  broken  with  a  rapid  rhythm  similar  to  that  of 
the  faradic  current.  They  produce  a  contraction  similar  to  that  from 
faradic  currents,  and  are  open  to  the  same  objections  as  to  abruptness 
of  beginning  and  ending  and  as  to  a  tetanic  condition  during  the  ap- 
plication, and  as  to  the  small  amount  of  electricity  which  traverses 

1  Bulletin  oflick'l  dc  la  Sneu'tr  d'ElootrothiTapio,  August,  1907. 


MEDICAL    KLKCTKICITY     AM)    Ko.NTOKX     HAYS 


the  muscle.     I. cduc  currents  or  any  other  Hinilarly  rapidly  interrupted 
currents  of  more  than   l.~>  ma.  would  produce   intolerable   convulsions. 


V 


I'itr.  •'>!'_'.  —  Sinusoidal     current     with  Fip.  31'5. — Isolated  induction  shocks. 

rli\  t  liinii-   \  .'iri.'ii  inn   in   -tn-nirth.      Mus-  Ali,ii]*t  rnuscuhir  contractions, 

i-ular     cdiitractioti     -iinil;ir     to     j)li\'sio- 

;i  i'_ric  nut-. 

These  current-  liave  a  slight  advantapo  over  faradic  currents  for  elect ro- 
mechanotherapy  in  the  fact  that  the  periods  of  current  and  the  strength 


V 


V 


Gaiffe's  Large  Apparatus  for  Electromechanotherapy.     The  appa- 
l- in.    '•'>  1  •>      ha      ;i    primary    coil    through    which    pa-<es    an    alter- 


ELECTRICITY    IN    DISEASES    OF   THE    XEUVOUS    SYSTEM 


489 


i in tint«;  run-out  which  may  ho  takon  from  tho  alternating  electric-light 
circuit  and  tho  strength  of  wliicli  is  regulated  by  a  volt-controller.  Xo 
intorruptor  is  required;  tho  alternating  current  in  tho  primary  generates 
a  sinusoidal  current  in  the  secondary  coil.  Tho  latter  is  pushed  back 
and  forth  by  an  electric  motor,  and  when  it  is  immediately  around  tho 
primary  coil,  generates  a  stronger  secondary  current  than  when  it  is 
removed  from  it.  Tho  adjustment  may  be  such  that  during  any  de- 
sired fraction  of  each  poriod  the  secondary  coil  is  entirely  removed  from 
around  the  primary  coil,  and  the  secondary  current  is  so  weak  as  to 
produce  no  muscular  contraction.  The  intervals  of  rest  between  the 
muscular  contractions  may,  therefore,  be  as  long  as  desired.  Tho 
muscular  contractions  are  excited  at  regular  intervals,  commence  and 


Fiiz.  .'Ufi. — Knullaxotonr  earn-ill   apparatus. 

end  gradually,  and  arc  very  much  like  physiologic  contractions.  The 
amount  of  electricity  which  flows  through  the  muscle  may  bo  measured 
by  a  milliamperemeter.  It  is  sufficient  to  produce  tho  trophic  effect 
of  elect  ricit  y. 

The  Enallaxotone  Current. — This  is  the  name  given  to  a  modi- 
fication of  the  faradic  current  suggested  by  Xicoletis.1  It  depends  upon 
the  transmission  of  tho  induced  current  from  a  regular  faradic  battery 
through  a  liquid  rheostat,  with  a  variable  distance  between  the  elec- 
trodes. At  certain  periods  in  the  motion  of  these  electrodes  there  is 
practically  no  current,  while  at  oilier  period-  almost  tho  full  intensity 
of  t  he  current  roaches  t  he  pat  ient.  There  is  consequently  an  undid atory 
contraction  in  muscles  to  which  sponge  electrodes  are  applied. 

An  Automatic  Rhythmic  Rheotome  for  Galvanic,  Faradic,  and 
deWatteville  Currents. —One  terminal  is  fixed  in  position,  while 
the  other  can  swing  around  horizontally  in  almost  a  complete  circle,  and 

November  1.").  1907. 


490 


MKDICAL    KLKCTKICITY    AND    ROXTGEN    RAYS 


is  normally  pressed  against  the  other  hy  the  action  of  a  spring  resembling 
the  hair-sprint:  of  a  watch.  An  electromagnet  is  placed  in  a  vertical 
position  near  an  iron  liar  on  the  revolving  contact,  hut  at  a  lower  level,  so 
that  the  revolving  contact  can  swing  back  and  forth  over  it.  \\henthc 
current  is  turned  on.  the  elect romagnet  attracts  the  iron  bar  and  breaks 
the  contact.  The  current  ceasing,  the  electromagnet  ceases  to  attract, 
and  the  sprint:  swings  the  iron  bar  back  into  contact  again.  _  1  he  rapid- 
ity of  interruption  may  be  varied  from  SO  to  L'OOO  times  a  minute.  '1  his 
is'  done  by  the  adjustment  of  a  stop  \vhidi  regulates  the  distance  to 
which  tin-  iron  bar  may  swing  away  from  the  point  ot  contact.  I  his 
apparatus  forms  part  of  the  author's  table  for  utilixing  the  1  10-volt  direct 
elect :  ic  curreni  for  galvanic  and  faradic  currents  and  for  diagnostic  illu- 
mination s  Fit:.  ^l 1.  p.  4st>\ 

Unidirectional  Undulatory  Currents  of  Low  Potential. —  Bordier's 
ol)servat ions'  lead  him  to  the  conclusion  ,hat  the.-e  currents  repre- 
sented  by  the  curve  in  Fig.  -(.\7  are  even  better  in  their  effect  upon 
mu-cular  atrophy  than  the  rhythmic,  gradually  alternating  currents 


Fit:.  o!7. — Unidirectional  undulatory  current. 

given  by  the  apparatus  i  p.  4W}>  employed  by  the  author.  The  apparatus 
for  producing  these  currents  differs  very  little  in  appearance  from  the  one 
alluded  to.  It  consists  of  a  rheostat  with  a  sliding  contact,  which  is 
moved  back  and  forth  from  the  xero-poinl  by  an  electric  motor. 

The  ph >/xioloi/ir  it't'ict*  of  tin  application  of  tin  *f  ciirmttx  to  muscles 
arc/  inntnr  nerres  are  quite  different  from  those  of  ordinary  galvanic 
current-;  made  and  broken  by  a  key.  or  by  the  metronome  int<  rrnpter. 
The  indit'fei'ent  electrode  should  be  a  large  plate,  measuring  n  by 
^  Indus,  and  covered  with  several  hivers  of  damp  doth  and  placed 
nude!-  the  patient's  back.  The  active  electrode  usually  connected 
with  the  negative  pole  is  a  sponge  electrode,  '_' I  inches  in  diameter. 
Tiie  speed  nl  the  motor  is  varied  so  that  it  takes  from  one  to  two 
second-  for  the  change  from  xero  to  a  maximum  current,  and  an  equal 
lent:'  h  •'  '  e  for  a  rei  urn  to  xero.  The  conl  ract  ion  wludi  occurs  is  of 
n  _••  lual  character,  like  a  physiologic  contraction.  The  strength  of 
the  current  required  to  product1  mu-cular  contraction  in  healthy  mus- 
i-  LTi'eatei1  'han  wit  li  sudden  makes  and  breaks  of  t  he  galvanic  current . 
: '  rophic  muscles  as  much  as  In  to  ."in  ma.  may  be  required.  These; 
heavy  current-  have  been  u-ed  by  Bordet.-  who  found  that  they  cause  a 
slight  burnhm  -en-ation  which  the  patient  can  -land,  instead  of  the 
severe  burning  feeling  from  the  ordinary  galvanic  application-.  The 
more  at  mphic  the  m  u  -de  i-.  the  -t  roniz'er  the  current  required.  As  to  t  he 
-peed  nl  '•  .  ilations  in  the  current,  the  more  natiiial  the  mu-de, 
the  more  rapid  -peed  i-  re(juired  to  produce  contraction.  The  muscle 
1  :'•'-  -'  m  it-  entire  ma--,  and  the  contraction  i-  limited  to 

de.     I  i<  >rdet  produced  a  n  inerea>e  of  si/e  and  strength 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM 


491 


in  the  biceps  of  healthy  men  by  applying  these  currents  to  that  muscle. 
Tiie  strength  of  current  was  10  ma.;  100  waves  of  current  were  applied 
every  day  for  fifty  or  sixty  days,  with  an  increase  of  '2  or  3  cm.  (0.x 
inch  or  l.'J  inches)  in  circumference.  This  was  a  slightly  greater  in- 
crease than  was  produced  on  the  other  arms  of  the  same  subjects  by  a 
rhythmic  undulatory  galvanic  current  with  a  change  of  polarity. 

These  currents  are  valuable  in  the  treatment  of  muscular  atrophy. 

Leduc  Currents. — Lc<luc\^  Apparatus  for  Low-tension  Interrupted 
(.'urrcntx.- — The  constant  current  from  a  galvanic  buttery,  a  storage- 
battery,  or  a  dynamo  is  interrupted  bv  a  wheel  interrupter,  which  is 
kept  in  revolution  by  an  electric  motor.  The  interrupter  is  placed  in 
series,  so  that  one  wire  from  the  batterv  leads  to  the  interrupter,  and  a 
wire  leads  from  the  interrupter  to  one  of  the  electrodes  applied  to  the 


Fiu;.  .'31S.  —  I.  cduc  interrupter. 


patient.     The  wire  from  the  other  electrode  applied  to  the  patient  leads 
to  the  other  pole  of  the  battery. 

The  wire  leading  from  the  battery  to  the  interrupter  is  connected 
with  a  stationary  brush  which  has  a  broad  surface  for  contact  with  the 
rim  of  a  revolving  disk.  The  latter  consists  of  metal,  but  has  two 
insulated  sections  at  opposite  sides.  The  wire  leading  away  from  the 
interrupter  is  connected  with  another  brush  contact,  the  position  of 
which  is  adjustable.  When  the  movable  brush  is  directly  opposite  the 
fixed  one.  as  in  Fig.  318,  A.  both  brushes  are  in  contact  with  the  con- 
ducting part  of  the  disk  at  the  same  time  and  for  the  same  length  of 
time.  As  the  disk  revolves  at  a  uniform  speed,  the  current  Hows  fora 
certain  length  of  time  and  then  ceases  to  flow  for  a  certain  length  of 
time.  These  periods  of  current  and  absence  of  current  are  exactly  pro- 
portional  in  duration  to  the  length  of  the  conducting  and  the  insulated 
poll  ions  of  the  circumference  of  the  wheel. 

Displacing  the  movable  brush  (as  in  B.  Fiir.  318)  so  that  when  every 
pail  of  the  fixed  brush  is  in  contact  with  o;ie  end  of  the  conducting 
section,  while  only  half  of  the  movable  brush  is  in  contact  with 
the  other  end.  produces  a  change  in  the  relative  duration  of  tin- 
periods  of  current  and  no  current.  With  the  same  speed  of  rotation  the 
periods  of  current  are  only  half  as  long  as  before,  and  the  periods  of  no 
current  are  increased  by  a  certain  fraction.  Reference  to  diagrams  (.' 
and  1)  (Fit:'.  318)  shows  that  while  the  current  begins  to  flow  as  soon  as 
the  contact  is  made  with  the  stationary  bru>h.  it  is  arrested  before  con- 
tact with  the  stationary  brush  has  ceased. 

Different  positions  of  the  movable  brush  give  periods  of  current 
flow  which  are  equal  to,  or  are  only  \.  !,.  ['„.  _,',,-.  or  ,-,',-„  the  duration  of 
the  periods  of  current  arrest. 

1  Arch.  d'elect.  med..  September  \~i.  I'.Mo. 


402 


MKDH  AI.    KL1XTKH  ITY    AND    ROXTGEN    RAYS 


The  number  nt'  periods  per  minute  is  varied  l>y  a  rheostat  controlling 
the  motor  which  turns  the  wheel  of  the  interrupter. 

The  -tivnmh  of  current  flowing  during  the  periods  of  contact  is 
regulated  by  the  ordinary  means.  In  the  case  of  a  galvanic  battery, 
one  can  use  a  cell  selector,  reii'iihiting  the  nuniher  of  cells  in  series  or  in 


FL-.  Ml'.i.  Character  of  I 

parallel  u!'  a  rheostat  regulating  the  outside  resistance.  A  rheostat  will 
vvnerally  be  required  with  a  storage-battery.  Koth  a  rheostat  and  a 
volt-controller  or  shunt  are  generally  required  when  the  lid-volt  direct 
elect  lie-light  current  is  used. 

The  strength  of  current  ordinarily  required  is  less  than  with  the 
•  ic  current  u-ually  from  -/,,-  to  M  ma.  The  maximum  strength 
of  "i1 1  to  sd  or  more  ma.  sometimes  used  with  the  galvanic  current  is 
never  to  be  used  with  the  Leduc  current-.  The  effect  of  the  latter  is 
that  i)l  a  series  of  abrupt  makes  and  breaks,  and  this  would  be  exceed- 
ingly disagreeable,  and  perhaps  dangerous,  with  strong  currents. 

'1  he  current  si  re n^t  h  may  be  measured  by  an  aperiodic  galvanometer. 
Thi-  will  indicate  fairlv  well  the  average  or  effective  strength  of  the 


current,  and  from  thi-  and  the  relation  between  the  period-  of  flow  and 
::•:•-;  one  may.  if  de-ired.  calculate  the  ab-olute  -trength  of  the  cur- 
rent when  act  u.ally  fli  iwinu'. 

The  difference  iii  potential  at  the  two  electrode-  where  they  are  ap- 
plied to  the  patient,  and  al.-o  the  re-i-tance  of   the  patient's  body,  may 
be  determined    by    making  a   very   brief  ol  i-ervat  ion   with   a   voltmeter 
, ' , '    wit  h   the  1  \v<  i  elect  r<  u  le-. 

/•'    nttnuli  ihi'*     I nh  rrn/tfi  r.-     Frimaudeau1     lias     devised     a     simple 

luciny  currenis  of  the   I.ediic  type.      An  ordinary  faradic 

coil  with  •<   -oft   iron  eore  has  it-  own  vibrating  interrupter  at   one  end. 

At    ':.'    otln  •    i  nd   the  alternate  magnet  i/at  ion   and  demagnetisation  of 

upon  a  vibrating  hammer  which  make-  and  breaks  a 

'    thai    ha-  no  connection  with  either  the  primary  or  the 

•    I  he  farai  lie  c(  nl. 

'  '•'  '    (, 'it'ii   ( '  urn  nix.      I'.ach  successive  period  gives  the  same 

-t  i    •  .  • ;   of  current  flowing  for  the  -ame  length  of  t  i  me  and  in  the 

It  ':  •    I  ;.'••,,,.  Li 'I'll-  iiml  l-'nmilic  Curri  nh    Flu-.  iil'J  and  iVJO).— 

;  •  '  -.  on  i  he  ot  her  hand,  -how  periods  ol  current  in  alt  er- 

•  ••'•  -t  renytli  and  duration  of  the  successive  impulses, 

I  '     M",iir,Mle.     M;,V,     I  '.  M  s.    ; ,  |  ,-t  ,':,  et     in     A  1 1  ,<T.    .],  ,Ur.    Klcct  H  >- 

.  ;\       N<i    ii    .!•;  '•.  .    I'M  v   |>.  LMO. 


ELECTRICITY    IX    DISEASES    OF    THE    NERVOUS    SYSTEM  493 

and  even  their  periodicity,  vary  in  consequence  of  imperfect  action  of 
the  vibrating  interrupter.  The  latter  may  not  make  perfect  contacts 
every  time. 

Advantages  and  Disadvantages  of  Leduc  Current*  a.s  Compared  with 
Farad ic  Current*. — The  advantages  are  chiefly  due  to  the  fact  that,  the 
successive  currents  are  of  the  same  known  strength  and  occur  at  a  known 
rate  per  minute.  The  muscular  response,  a  tetanic  contraction  lasting 
as  long  as  the  interrupted  current  is  turned  on,  is  similar  to  that  pro- 
duced by  faradic  currents,  but  electrodiagnosis  is  much  more  exact  with 
the  Leduc  currents.  It  is  also  easier  to  make  accurate  comparisons 
between  reported  cases  and  the  one  under  observation. 

The  disadvantage  is  that  the  successive  currents  arc  all  in  the  same 
direction,  and  the  same  polarization  occurs  which  has  such  a  tendency 
to  vitiate  measurements  and  cause  irritation  when  the  galvanic  current 
is  used.  The  faradic  current  is  alternating,  and  is  not  open  to  this 
objection.  This  objection  to  the  Leduc  current  may  be  overcome  by  the 
occasional  use  of  the  pole-changer,  without  which  no  electric  apparatus 
can  be  considered  complete,  or  by  the  use  of  an  apparatus  giving  alter- 
nating Leduc  currents,  or,  best  of  all,  by  transmitting  the  Leduc  currents 
through  the  author's  rhythmic  rheostat  and  pole-changer. 

The  Leduc  apparatus  may,  therefore,  be  considered  a  most  valuable 
improvement  over  the  faradic  coil  for  diagnostic  purposes.  Its  ad- 
vantages for  treatment  are  not  so  well  established,  although  Leduc's 
"electric  sleep"  is  thought  to  be  a  condition  produced  by  the  interrupted 
unidirectional  current  which  the  alternating  discharge  from  a  faradic  coil 
will  not  produce.  There  is  no  doubt  at  all  that  the  utmost  regularity 
in  the  successive  currents  is  desirable  in  every  case,  but  unidirectional 
currents  may  not  always  be  preferable  to  alternating  ones.  The  fact 
that  the  induced  currents  from  a  faradic  coil  have  a  higher  voltage  than 
that  of  the  direct  primary  current  in  the  same  coil  does  not  enter  into 
the  problem.  The  Leduc  apparatus  allows  of  the  application  of  cur- 
rents of  equally  high  tension.  Both  the  Leduc  and  the  faradic  currents 
are,  however,  known  as  low-tension  currents.  High  tension  is  a  term 
that  applies  more  properly  to  the  discharge  from  a  static  machine,  an 
Oudin  resonator,  or  a  Ruhmkorff  coil.  It  means  a  sparking  distance 
measured  in  inches,  not  in  thousandths  of  an  inch,  as  in  the  Leduc  and 
the  faradic  currents. 

Leduc  has  found  that  the  most  effective  stimulation  of  muscular 
contraction  is  obtained  when  the  duration  of  the  passage  of  the  current 
's  TIMIIT  second  each  time.  Adjusting  the  apparatus  for  this  length 
of  current  waves  and  for  a  frequency  of  100  periods  a  second,  it  is 
simply  necessary  to  determine  the  voltage  necessary  to  excite  muscular 
contraction:  or,  what  is  sometimes  more  convenient,  the  milliamperage 
required  with  electrodes  of  a  certain  area  of  contact. 

The  contractions  ordinarily  elicited  by  electricity  are  due  to  the 
dosing  and  opening  of  the  circuit,  and  not  to  a  uniform  flow  or  absence 
of  current.  They  seem  to  be  due  to  the  variable  period  of  the  current; 
a  very  short .  but  still  a  measurable  length  of  time  during  which  the  cur- 
rent is  increasing  from  zero  to  its  maximum  strength  or  diminishing  to 
zero. 

The  variable  period  of  the  current  at  the  closure  of  a  galvanic 
circuit  has  been  found  by  Blaserna  to  be  0.0004s  second,  and  at  the 
opening  of  the  circuit  it  is  0.00027  second. 


494  MKD1CAL    KLECTRICITY    AM)    K(").\TtiK.\     KAYS 

These  facts  seem  to  throw  some  doubt  upon  the  value  of  the  chief 
feature  of  the  Leduc  currents  —  /.  c.,  the  ability  to  regulate  the  exact 
duration  of  the  successive  periods  of  current  flow,  but  this  is  hardly 
a  correct  view  of  the  case.  Though  the  period  during  which  the  current 
flows  uniformly  is  a  period  without  practical  physiologic  effect,  its 
duration  directly  controls  the  length  of  time  between  the  physiologic 
effect  due  to  the  closure  and  that  due  to  the  opening  of  the  circuit,  and 
we  know  what  a  very  great  influence  rapidity  of  succession  in  electric 
impulses  exerts  upon  physiologic  effect. 

KKUINNINC,     or     MUSCULAR     RKACTIOX     WITH     I.EDUC     CURRENTS 
PERIOD. 


VOLTS. 

TIME  oy  PASSM.K  OF  Crit- 

KENT    IN   SKCOVI>S. 

-)'2 

0.  00001 

15 

0.0001 

15 

0.0002 

12 

0.0003 

11.5 

0.0004 

10.5 

0.00(1.") 

9.5 

O.OOOti 

9 

0.0007 

8.5 

0.0009 

7 

0.001 

EjTi c(  of  Lednc  Currents  upon  Animal  Development  and  Nutrition. — 
In  experiments  by  Bordier  and  Honnenfant1  the  negative  electrode 
was  placed  at  the  nucha  and  the  positive  electrode  over  the  sacrum;  the 
skin  was  shaved. 

Rabbits  about  three  iccckx  old  were  treated  every  other  day.  The 
interruptions  were  .'-J7120  a  minute.  The  first  rabbit  experimented  upon 
had  convulsions  and  fell  over  on  its  side  with  a  current  of  IS  ma.  The 
current  was  then  reduced  to  S  ma.,  and  allowed  to  flow  for  ten  minutes. 
At  the  second  such  treatment  the  rabbit  died,  probably  from  com- 
pression of  the  trachea  by  an  elastic  band  u.-.ed  to  hold  the  electrode 
in  place.  Other  rabbits  showed  complete  anesthesia  and  a  somewhat 
accelerated  respiration  with  a  current  of  IS  ma.,  and  this  was  followed 
by  "N  ma.  for  ten  minutes.  The  animal  showed  no  bad  effects.  Sub- 
-eijuent  applications  to  this  rabbit  were  1">  ma.  at  the  start,  followed 
by  x  ma.  for  ten  minutes.  Only  twice  during  the  two  months'  course 
of  treatment  did  the  rabbit  show  anv  bail  effects.  On  these  occasions 


than  the  control  rabbit  which  was  not  treated,  it  weighed  100 
less  than  the  other  at  the  end  of  two  months.  It  had  grown,  but 
la>t  as  if  it  had  not  been  treated  by  electricity.  During  a  week's 
ission  m  the  treatment  it  mv\v  faster  than  the  other  rabbit. 

ibbitn  weighing  over  '•>   kilograms   were  treated  in  the  same 
'•  irrent    was  interru])t<'(l    J.'l'JO  times  a  minute,  and  was  run 
ia.  at  first  to  produce  anesthesia,  and  was  kept  at   10  ma. 
I  hese  t  real  mei it  s  were  triven  every  da  v  for  1  wont y-f our 
that    there   was   a    reduction   of    10   per  cent,   in   the 
in  t  he  radiat  ion  of  heat   from    }'>(}() 

period 


KLKCTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM 


405 


of  the  interrupter,  and  ouch  ton  minutes'  treatment  at  8  ma.  equaled 
.'3r27  coulombs;  and  at  10  ma.  equaled  4  coulombs. 

These  results  may  find  a  practical  application  in  the  treatment  of 
obesity. 

They  certainly  show  that  a  lon.tr  course  of  treatment  by  these  rapidly 
interrupted  galvanic  currents  should  not  generally  be  applied  in  the 
ease  of  growing  children.  This  applies  more  particularly  to  treatment 
applied  in  such  a  way  that  the  spinal  cord  acts  as  the  principal  conducting 
path. 

PRACTICAL  EXAMPLES  OF  THE  USE  OF  CONDENSERS  IN  ELECTRO- 
THERAPEUTICS 

IN  CONNECTION  WITH  THE  STATIC  ELECTRIC  MACHINE 

To  Apply  the  Static  Induced  Current  (Fig.  321).— The  inner 
armatures  of  two  Leyden  jars  are  connected  with  the  two  poles  of  the 
static  machine,  while  electrodes  connected  with  the  outer  armatures  are 
applied  to  the  patient.  Kaeh  time  the  inner  armatures  are  charged,  a 
current  is  induced  through  the  patient  in  one  direction.  And  when  the 
inner  armatures  are  discharged  by  the  passage  of  a  spark  between  the 
two  discharging  rods  of  the  static  machine,  a  current  passes  through 
the  patient  in  a  direction  opposite  to  that  of  the  charging  current.  The 
inner  armature  of  the  jar  connected  with  the  positive  pole  of  the  static 
machine  becomes  charged  with  positive  electricity,  and  by  induction 
repels  positive  electricity  from  the  outer  armature  of  the  same  Leyden 
jar  through  the  patient  to  the  outer  armature  of  the  other  jar.  Nega- 
tive electricity  is  repelled  from  the  outer  armature  of  the  jar  connected 


Fig.  321. — Static  induced  current,  regulated  by  slowly  separating  A  and  B. 


with  the  negative  pole  of  the  static  machine  through  the  patient  to  the 
other  jar.  On  the  discharge  of  the  Leyden  jars  the  charges  on  the 
external  armatures  are  released  and  pass  in  the  opposite  direction.  It 
is  convenient  to  speak  of  the  direction  in  which  the  positive  charge 
passes  as  the  direction  of  the  current,  and  this  is  from  the  jar  connected 
with  the  positive  pole  while  the  Leyden  jars  are  becoming  charged,  and 
in  the  opposite  direction  while  they  are  being  discharged  by  the  passage 
of  a  spark.  The  rapidity  of  the  alternations  is  not  very  great — it  is 
merely  that  of  sparks,  and  they  may  be  readily  counted.  The  quantity 
of  electricity  transmitted  through  the  body  depends  principally  upon 
the  si/.e  of  the  Leyden  jars,  while  its  tension  depends  principally  upon 
the  length  of  the  spark-gap  and.  of  course,  is  limited  by  the  power  of  the 
static  machine. 

An  isolated  condenser  spark  may  be  applied  from  a  small  Leyden 


401) 


MKDICAL     KI.KCTHICITY     AM)    ROXTeiKX    KAYS 


jar  already  chargvel.  The  patient  is  not  insulated,  and  the  external 
armature  of  the  Leyden  jar  is  connected  with  the  ground,  while  the  other 
pole,  the  brass  knob  connected  with  the  inner  armature  of  the  Leyden 
jar.  is  brought  near  the  patient  (.Fig.  322).  A  spark  passes  to  the 
patient,  and  produces  physiologic  effects  which  are  of  diagnostic  and 
therapeutic  value,  and  especially  so  from  the  fact  that  the  spark  can  be 
applied  exactly  to  the  desired  spot,  and  can  be  perfectly  regulated  as  to 
volume  and  consequently  as  to  voltage.  The  author's  technic  is  to  have 
the  patient  seated  or  standing  or  lying  about  .'!  feet  from  the  static 
machine,  but  not  upon  an  insulated  platform.  The  operator  holds  a 
Leyden  jar.  his  fingers  grasping  the  outer  metal  coating.  A  wire  or 
chain  which  need  not  be  insulated  is  fastened  to  the  outer  coaling,  and 
at  its  other  extremity  to  a  water  or  gas-pipe,  which  effectually  grounds 
it.  The  static  machine  is  to  be  in  operation,  and  its  discharging  rods 
are  to  be  fixed  at  a  certain  distance^  apart,  and  this  regulates  the  voltage 
of  the  charge1.  The  latter  cannot  exceed  the  amount  required  to  spark 
across  the  air-space1  between  the  discharging  rods.  The  Leyden  jar 
is  held  so  that  the  inner  electrode,  that  is,  the  brass  rod  connected  with 
the  inner  metal  coating  or  armature1,  touches  one1  of  the  discharging 
rods  of  the  static  machine1.  It  take's  only  a  short  lime1  completely  to 


toground 
I'lir.  '-'>'2'2.  —  Isolated  Leyden  jar  spark  applied  to  patient. 

charge  the  Leyden  jar.  and  it  remains  charged  until  the  iniuM'  elee'trode 
i-  applied  to  the  patient.      A  spark  is  then  produced,  the  patient  and  the1 
earth    completing    the    connection    between    the    internal    and    exteM'nal 
armatures.      I  mm   the  standpoint    ot    convenience   in   handling,   as  well 
a-  wi'h  regard  to  the  physiologic  effect,  the  appropriate  si/,e  of  Leyde1!) 
jar  i-  one  coti-i-t  nm'  ot  a  glass  bottle  10  inches  long  and  about  '2\  inches 
in  diameter,  with  external  ami  internal  armatures  covering  the  bottom, 
and  extending  ;»j    inches  up  on  the  side.-  ol    the  jar.      The  operator  ex- 
perience-  1,1,  -en-ation  either  when   charging  the  jar  or  when  applying 
the  spark   to  the  patient.      The  capacity  of  the  same    Leyden   jar  is.  of 
cour-e,  Always  the  same,  but    the  quantity  of  electricitv  which  it    takes 
to   charge    'In-   capae-ity,    as   well    as   its   tension,    i-   increased    when    the 
di-taiicc  between  the  discharging  roil-  (if  the  -tatic  machine  is  increased, 
distance   -lioiiM    be    ',    inch   at   the  commencement   of  the  examina- 
••••••     I.  and    mav    be   Lrradnally    incre'ascd    to    I.   or   possibly 

ndimj  upon  the  nature  of  the  case1,  the  sensitiveness  of 
the  I-,  -;:,!,  to  which  the  -park  is  applied,  and  the  individuality  of  the 
patient.  The  -park  may  be  applied  through  the  clothes  or  directly 
to  t  de  -km .  I.-olat  ed  condenser  disc  ha  rges  mav  be  a  ppiiei  1  in  rapid  suc- 
ces-ion,  and  every  one  he  perfectly  regulated.  Almost  anv  tvpe  of 


ELECTRICITY    IN"     DISEASES    OF    THE    NERVOUS    SYSTEM 


497 


static  machine  will  charge  a  Leyden  jar  amply  for  this  jmrpose.  It 
does  not  require  one  of  the  large  glass-encased  machines  with  eight  to 
sixteen  or  twenty  glass  j>lates  used  for  the  generation  of  the  j'-ray. 

Condensers  for  stimulating  muscles  or  nerves  have  a  cajmcitv  of 
ifiW'  ion-  or'  tlt  tn(>  most.  i1,)  microfarad. 

The  Leyden  jar  cannot  he  successfully  charged  for  use  in  exactly 
this  way,  either  from  an  induction-coil  or  a  transformer.  The  alternat- 
ing character  of  the  impulses  prevents  the  armature  which  is  applied  to 
one  j)ole  of  the  coil  from  receiving  a  j>ermanent  charge  of  either  {positive 
or  negative  electricity. 

Leyden  Jars  or  Other  Condensers  as  an  Essential  Part  of  High- 
frequency  Apparatus. — A  single  example  will  suffice  to  illustrate  this 
use  of  the  condenser  principle.  Fig.  323  shows  a  form  of  resonator 
employed  by  the  author.  P  and  P'  are  the  jioles  of  an  x-ray  coil  or  an 
x-n\y  transformer,  whose  discharging  rods  or  spintremeter  are  wide 
apart.  A  conducting  cord  passes  from  each  j>ole  of  the  coil  to  the  in- 


i<z.  .'52.3.  —  Leyden  jars  as  part  of  apparatus  for  gem-rut  ing  high-frequency  currents. 


ternal  armature  of  a  Leyden  jar,  and  between  the  internal  armatures  of 
the  two  jars  there  is  an  adjustable  spark-gap,  S.  ( i..  surrounded  by  a  glass 
cylinder  to  muffle  its  noise.  The  external  armatures  of  the  two  jars  are 
connected  one  to  tin1  beginning  of  a  flat  spiral  of  insulated  wire,  and  the 
other  to  the  second,  third,  or  fourth  turn  of  the  spiral,  according  to  the 
effect  desired.  The  internal  armatures  of  the  jars  act  as  large  capacities 
because  each  forms  part  of  a  condenser.  A  sufficient  outjnit  is  required 
from  the  coil  or  transformer  to  overcharge  the  Leyden  jars  at  each  im- 
jHilse  from  the  coil.  Taking  the  right-hand  jar.  for  instance,  its  internal 
armature  receives  at  a  certain  instant  a  positive  charge  which  drives 
the  positive  electricity  from  its  external  armature  through  the  desired 
number  of  turns  in  the  spiral  resonator  to  the  outer  armature  of  the  other 
jar.  At  the  same  instant  the  internal  armature  of  the  other  jar  has 
received  a  negative  charge,  and  the  negative  electricity  is  repelled 
from  its  outer  armature  through  the  resonator  to  the  outer  armature  ot 
the  other  jar.  The  result  is  that  the  outer  armature  of  one  Leyden  jar 
is  charged  with  positive  and  that  of  the  other  jar  with  negative  elee- 


498  MEDICAL    ELECTRICITY    AND    RONTGE.N    RAYS 

trieity.  Though  there  is  a  complete  metallic  connection  between  these 
two  opposite  charges  through  the  wire  of  the  resonator,  they  are  held 
bouiul  upon  the  surface  of  the  glass  by  the  charges  upon  the  inner  arma- 
tures. When  the  latter  are  discharged  by  a  disruptive  discharge  across 
the  spark-gap,  and  the  charges  on  the  external  armatures  are  liberated, 
a  discharge  at  mice  takes  place  through  the  resonator  turns,  and  this  is 
of  the  same  high-frequency  character  always  found  in  a  discharge  of 
static  electricity,  and  especially  the  discharge  of  a  Leyden  jar.  Thou- 
sands of  oscillations  occur  in  the  conductor  through  which  the  discharge 
takes  place  in  the  small  fraction  of  a  second  required  completely  to 
neutralize1  the  two  opposite  charges.  The  term  high  frequency  refers 
to  these  millions  of  oscillations  each  second,  not  to  the  few  score,  or 
possibly  a  few  thousand,  disruptive  discharges  a  minute  which  are 
directly  visible  and  audible  at  the  spark-gap.  The  condenser  stores  up 
the  energy  of  each  current  induced  in  the  secondary  of  the  induction-coil 
or  transformer,  and  gives  it  what  may  be  called  a  xtatic  (futiliti/,  resulting 
in  inconceivably  rapid  oscillations  each  time  that  a  discharge  occurs. 

The  resonator  or  spiral  wire  acts  as  a  self-inductance,  and  increases 
the  voltage  of  the  electricity  supplied  to  it,  so  that  an  efrluve  from  1  to  4 
inches  long  may  be  obtained  at  the  electrode. 

The  condensers  act  in  the  same  way  in  all  the  high-frequency  appara- 
tus, in  connection  with  resonators  and  solenoids  of  different  types. 
These  act  either  to  increase  the  electromotive  force,  or  as  choke  coils  to 
reduce  it.  or  again,  in  autoconduction  cages,  to  induce  high-frequency 
currents  in  the  patient. 

Condenser  Electrodes. — These  are  especially  useful  in  the  applica- 
tion of  high-frequency  currents.  Fig.  324  shows  one  type  with  a  leading- 
in  wire  and  a  metallic  rod  extending  down  through  the  middle  of  a  glass 


it'.  .')24.  —  A  condenser  rlectrod 


Tube,  which  i-  closed  at  the  extremity.  The  tube  contains  air  or  other 
Lra-  which  may  or  may  not  be  partially  e\hau.-ted.  When  this  elec- 
tro.!>•  i-  applied  TO  the  skin  or  to  a  mucous  membrane,  the  patient's 
body  becomes  the  external  armature  of  the  condenser.  The  glass  and 


•''"'  "f  the  tube  form  the  dielect  ric  and  the  metal  rod  the  inner  armature. 
Another  cotiden-er  electrode  '  Fiir.  :>2.~>  consists  of  a  metal  rod  with  a 
hard-rubber  covering. 

vacuum  electrode-  'Fi<r.  :{2»',]  for  high-frequency  cur- 
rent- have  a  -imilar  principle.  If  they  have  a  leading-ill  wire  the  com- 
municatioii  ot  the  high-frequency  charge  to  the  content-  of  the  tube  is 
perfectly  direct.  If  there  i-  no  wire,  the  metal  socket  of  the  handle 


ELECTRICITY    IN     DISEASES    OF    THE    NERVOUS    SYSTEM  499 

forms  one  armature  of  a  condenser  in  which  the  dielectric  is  formed  by 
the  glass  wall  of  the  tube  where  it,  is  in  contact  with  the  metal  socket. 
The  handle  is  charged  with  positive  and  negative  electricity  in  exceed- 
ingly rapid  succession,  and  with  each  positive  charge  of  the  handle  the 
positive  charge  of  the  inner  armature,  the  contained  partially  rarefied 
gas,  is  repelled.  With  each  negative  charge  of  the  handle  the  positive 
charge  of  the  gaseous  contents  surges  back  to  a  point  within  the  glass 
tube  where  it  is  separated  from  the  charged  handle  by  only  the  thick- 
ness of  the  glass.  At  the  other  extremity  of  the  vacuum  tube  a  similar 
inductive  action  is  produced;  the  positive  charge  repelled  from  the 
region  of  the  handle  forms  the  positive  charge  of  a  condenser  whose 
inner  armature  is  the  rarefied  gas,  whose  dielectric  is  the  glass  wall  of  the 
tube,  and  whose  external  armature  is  the  surface  of  the  patient.  The 
latter  receives  by  induction  a  negative  charge,  negative  electricity  in 
the  patient's  body  being  attracted  to  the  surface  of  the  glass  dielectric, 
and  positive  electricity  being  repelled  to  the  most  distant  possible  part 
of  the  patient's  body.  With  the  exceedingly  rapid  alternations  in 
polarity  which  characterize  the  high-frequency  current,  electrostatic 
charges  surge  back  and  forth  through  the  patient's  body.  These1  orig- 
inate' in  and  are  concentrated  at  the  surface  of  contact  with  the  vacuum 
electrode,  where  the  local  effect  is,  therefore,  greatest.  They  extend  to 
every  portion  of  the  body,  as  can  be  easily  demonstrated  by  touching 
any  part  of  the  patient  lightly  with  the  tip  of  the  finger-nail.  The 


characteristic  violet  light  is  seen  between  the  finger  and  the  patient, 
and  there  is  a  slight  smarting  sensation  fiom  the  passage  of  innumerable 
microscopic  sparks.  The  experiment  produces  no  shock  or  muscular 
contraction,  and  none  of  the  sensation  which  has  so  long  been  associated 
with  the  name  of  electricity.  Chemic  changes  produced  by  the  current 
in  the  deepest  tissues  show  that  the  charge  is  not  limited,  as  in  the  case  of 
static  electricity,  to  the  surface1  of  the  body,  but  that  it  also  penetrates 
every  portion  of  the  body. 

Another  h/pc  of  condenser  electrode  is  made  by  filling  a  glass  tube 
with  a  liquid  which  is  a  good  conductor,  or  by  coating  its  interior 
with  metal.  Condenser  electrodes  filled  with  salt  solution  have  a  greater 
elect  ric  capacity  than  vacuum  electrodes  of  the  same  size  and  shape. 
They  give  a  somewhat  stronger  current  with  the  same  adjustment  of 
the  high-frequency  apparatus,  but  do  not  themselves  become  hot,  as  do 
the  vacuum  electrodes.  This  is  a  noteworthy  advantage  over  the  lat- 
ter. 'l'he\'  arc1  not  liable  to  be  ruined  by  breaking  down  of  the  vacuum, 
leakage  that  is.  which  is  practically  impossible  to  repair  in  the  case  of  a 
vacuum  electrode,  and  which  is  usually  the  result  of  overheating  at  the 
handle  or  of  an  excessive  current  punct  uriim  \  he  dielect  ric.  or  of  mechanic 
violence,  screwing  the  handle  on  too  tight,  or  knocking  the  tube  against 
some  hard  object.  This  type  of  condenser  electrode  does  not  get  hot; 
it  does  not  contain  a  vacuum,  and  is.  therefore,  not  affected  by  a  minute 
fissure  which  would  terminate  the  usefulness  of  a  vacuum  electrode. 


500 


MKDICAL    KI.KCTHICITV     AND    HONTCKN    KAYS 


It  docs  not  contain  a  space  filled  with  violet  light  and  ultraviolet  rays, 
but,  like  the  vacuum  electrode,  it  generates  a  certain  amount  of  ultra- 
violet rays  where  minute  sparks  pass  between  the  glass  and  the  surface 
of  the  patient.  In  other  respects  its  effects  seem  to  be  identical  with 
those  of  the  vacuum  electrode. 

'/'//»  Rmsnn  \\'li//  it  (iluss  Tulic  irhich  Hti*  Lost  its  \  iii'tiuni  Docx  Xot 
.1/7  us  n  Cotnh  ns<-r  {•'.!<  <•(  rmli  . —  In  the  first  place,  a  id  ass  lube  which  has 
not  been  exhausted,  but  which  has  only  a  small  fraction  of  an  inch  of 
air  between  the  nl ass  in  contact  with  the  patient  and  the  charged  wire 
or  other  conductor,  reallv  does  act  as  a  u'ood  condenser  electrode  for 


Con 


frtedi 


high-frequency  currents.  Such  an  electrode  may  consist  of  a  glass 
tube  scaled  at  the  end  applied  to  the  patient,  and  having  a  wire  ex- 
tending practically  its  whole  length.  A  small  thickness  of  air  acts  as 
part  of  the  dielectric,  the  other  part  being  the  glass  wall,  and  the  two 
armatures  being  the  wire  and  the  patient. 

The  ordinary  vacuum  electrode  presents  quite  different  conditions. 
There  is  a  lonu'  .-pace  of  perhaps  as  much  as  (>  inches  between  the  glass 
in  contact  with  the  patient  and  the  charged  metal  handle  or  leading-in 
wire.  Klecirjc  induction  cannot  take  place  to  a  sufficient  extent  in  a 
condenser  having  a  dielectric  (>  inches  thick,  and  air  at  the  ordinary 


H  F 

y     '    ^ 

4- 

pi1'  --  .••         i!  not   acl   as  a  conductor  of  electricity  unless  ioni/ed.      And 

-  not  a  -uflicienlly  <^<><>t\  conductor  for  this  purpose.      The 

'•••'••  1'  •  con  t  a  ins  air  or  ot  her  iras  at  a  pressure  of  }  ti'n  n  at  mos- 

'  '  •     '  pei-~|er  (||.H-]-,.(.  ,,|   vacuum.   \\  1 1 1  c  1 1   |-  all  excellent    conductor  of 

n  rent . 

ni    tin    rrnitli  nwr  ilirtrnili    may   be   ihagrammatically 

hown  a-  in   I  :-.  '.','27.      At  a  certain  in.-tani  the  metallic  handle  from  the 

til-    may    have    a    positive    charge.      It     induces. 

'•     '    tiomt.   a    negative   charge   m    the   conductiim 

'1  air  or  .-aline  -olution,  contained  in  the  tube,  and 

1    ''...    |ue?ii  :         ivi-  charge  m  the  di-tal   portion  of  the  conducting 


ELECTRICITY     IX     DISEASES    OK    THE     NERVOUS    SYSTEM  501 

medium.  There  again  u  condenser  action  occurs  inducing  a  negative 
charge  in  the  portion  of  the  patient  in  contact  with  the  glass.  At  the 
next  instant  the  polarity  is  reversed  at  every  point  in  the  series. 

The  Operation  of  the  Condenser  Electrode  When  (it  Some  Distance  from 
the  Patient.— ¥ig.  328  shows  tliis  in  a  diagrammatic  way.  At  the  instant 
that  the  distal  portion  of  the  conducting  medium  is  charged  with  positive 
electricity,  a  condenser  action  takes  place,  producing  through  the  glass 
and  open-ail1  dielectric  a  strong  negative  charge  in  the  nearest  portion 
of  the  patient.  If  the  air-space  is  only  a  fraction  of  an  inch,  this  nega- 
tive charge  will  break  through  the  layer  of  air  as  an  effluve  or  as  a 
shower  of  sparks,  as  the  case  may  he.  In  the  diagram  a  negative  charge 
is  shown  to  have  accumulated  in  this  way  upon  the  surface  of  the  glass, 
held  there  just  as  in  the  "dissected  Leyden  jar." 

THE  USE  OF  CONDENSERS  IN  CONNECTION  WITH  INDUCTION-COILS 

This  is  of  the  greatest  importance,  and  has  been  considered  on  p.  148. 

NEURALGIA  AND  NEURITIS 

Satisfactory  distinctions  between  the  neuralgias  and  rieuritidcs  are 
not  easy  to  draw.  The  severe  neuralgias  pass  over  into  mild  or  severe 
neuritides,  whereas,  the  mild  neuritides  may  be  considered  as  neuralgias. 
It  is  largely  a  question  of  degree.  So  far  as  the  seven1  neuritides  are 
concerned,  however,  certain  grave1  alterations  are  found  in  the  nerve- 
trunks  which  are  not  known  to  exist  in  neuralgias.  Such  are  cell  in- 
filtrations in  and  about  the  nerve-fibers,  proliferation  of  new  connective 
tissue  causing  pressure,  and  various  degenerations  which  are  usually 
peripheral,  but  which  also  may  be  interpreted  as  central  in  origin. 

The  chief  neuralgias  which  are  amenable  to  electric  treatment  and 
which  the  electric  therapeutist  is  oftenest  called  upon  to  treat  are  those 
of  tin1  trigominal,  brachial.  the  musculocutaneous,  and  the  sciatic  nerves. 
There  are  other  neuralgias,  such  as  ovarian,  coccygeal,  the  neuralgias  of 
herpes,  etc..  which  occasionally  call  for  electric  treatment,  but  in  general 
those  of  the  facial  region,  brachial,  and  of  the  sciatic  distribution  are  the 
most  obstinate. 

In  the  consideration  of  the  treatment  of  the  neuralgias  one  should 
bear  in  mind  always  the  question  of  referred  pains.  These  referred  pains 
have  been  so  exhaustively  studied  by  Head,  Dana,  McKen/ie,  and  others 
that  we  are  now  in  a  position  to  refer  the  vast  majority  of  the  so-called 
neuralgias  to  certain  disturbances  in  the  viscera.  These  visceral  dis- 
turbances, as  i-  well  known,  send  or  cause  nerve  impulses  to  travel  to  the 
spinal  cord,  which,  coming  in  some  sort  of  contact  with  certain  sensory 
nerves  in  the  spinal  segment,  are  referred  to  the  skin  area  of  these  seg- 
mental  nerves. 

These  skin  areas  have  been  verv  accurately  mapped  out  by  the 
researches  of  the  authors  mentioned,  and  it  is  well  known,  through 
these  researches,  that  the  whole  surface  of  the  body  may  be  divided 
into  areas  which  correspond  to  or  represent  the  cutaneous  surface  in 
con  t  act  with  the  nerves  of  the  visceral  organs.  This  leads  to  the  develop- 
ment of  cutaneous  tenderness  in  practically  all  referred  pains,  and  this  is 
a  very  essent  ial  factor  in  the  diagnosis  of  this  type  of  so-called  neuralgias. 
These  cutaneous  tendernesses  have  a  marked  feature  in  contrast  with 
the  pains,  which  are  perceptible  over  the  area  of  a  nerve-trunk,  -uch  as 
are  frequently  seen  in  the  neuritides. 


502  MKDICAL    KLKt  THICITY    AND    ROXTGKN    RAYS 

Thus  in  the  invest igat ion  of  the  neuralgias  special  care  must  bo 
taken,  first,  to  outline  the  importance  of  visceral  diseases;  secondly, 
to  determine  if  such  neuralgias  may  he  due  to  growths  on  or  pressing 
upon  the  nerve-trunks;  and.  tinally.  to  consider  the  specific  type  of  herpes 
neuralgias  which  are  due  to  the  involvement  in  the  posterior  ganglion. 
It  should  he  borne  in  mind  that  such  involvement  in  the  posterior  gan- 
glion may  set  up  very  severe  neuralgias  without  a  corresponding  herpctic 
eruption,  although,  as  a  rule,  a  skin  eruption  is  apt  to  follow  the  inflam- 
mation of  the  posterior  root  ganglion.  These  herpetic  ureas  are  clearly 
outlined  in  works  on  neuralgia,  and  the  relation  of  visceral  disease  to 
herpetic  inflammation  is  one  of  the  most  interesting  chapters  connected 
with  sensory  localization. 

The  electric  treatment,  therefore,  of  the  different  neuralgias  must 
take  into  consideration  the  manifold  origin  of  these  affections.  The 
treatment  of  neuralgias  due  to  visceral  diser^es — in  other  words,  the 
referred  pain  neuralgias — consists  essentially  in  the  use  of  electricity 
as  a  eounterirritant,  the  counterirritant  being  applied,  if  possible,  in  the 
area  corresponding  to  the  viscus  affected.  Medical  treatment  of  the 
viscus  should  not  be  overlooked,  being  often  of  more  value  than  the 
electric  treatment  of  its  reflection  only,  so  to  speak. 

Referred  pains  in  the  head,  neck,  and  face  are  frequently  the  result 
of  disease  of  the  nose,  the  eye.  the  ear.  the  tongue,  the  teeth,  the  tonsils, 
the  larynx,  or  of  the  brain  itself.  Finally,  a  number  of  the  internal 
viscera,  such  as  those  of  the  thorax  and  abdomen,  which  receive  their 
nerve-supply  from  the  vagus  or  the  glossopharyngeal  nerves,  are  capable 
of  inducing  referred  pains  in  and  about  the  head  and  neck,  and  some  very 
persistent  neuralgias  of  the  face  are  often  due  to  disease.'  of  viscera  below 
the  diaphragm. 

Kvery  case  of  neuralgia  or  neuritis  calls  for  an  .r-ray  examination  of 
the  teeth.  The  cause  is  often  dental  infection. 

\Y.  II.  Schmidt1  gives  this  treatment  for  neuritis:  Diaynosi*:  In 
neuralgia  and  myalgia  the  electric  reaction  is  always  normal.  Neuritis 
produces  altered  reaction  varying  from  a  sluggish  response  or  hypo- 
excitability  to  complete  reaction  of  degeneration  and  loss  of  tendon 
reflex.  1'or  ti'intnn  >/t,  countcrirritntion  is  produced  by  a  vacuum  elec- 
trode from  one  pole  of  an  induction  coil  or  the  static  brush  discharge  or 
the  high-frequency  eflluve.  Ultraviolet  rays  may  be  used  for  a  deep 
effect,  lasting  two  or  more  days.  II  cat  is  applied  from  a  500  watt  lamp 
for  a  half-hour  or  by  diathermy.  Acntr  nruritix:  Absolute  rest,  mild 
positive  galvanization  or  diathermy.  Siihncutr  m'urifi*  is  benefited  by 
•  >00  wat  t  lamp  one-halt'  hour  or  more,  posit  ive  galvanizal  ion  one-quarter 
hour,  high-frequency  vacuum  electrode  mildly  along  the  course  of  the 
nerve;  th.'  static  brush  discharge  over  the  most  painful  area  until  defi- 
nite redness  occurs;  or  high-frequency  efiluve.  the  high  tension  faradic 
current,  diathermy  one-half  hour,  counterirritation  by  ultraviolet  rays, 
or  the  static  wave  current  beginning  with  a  short  gap  of  1  inch  or  less 
and  tor  a  -hurt  duration.  Chronic  neuritis  n\n\  be  t reat ed  bv  the  heavy 
static  wave  current,  electric  light  baths,  and  muscular  contractions. 
.-  i-  treated  by  500  watt  incandescent  lamp,  rhythmic 
muscular  contraction-;  produced  by  any  electrical  means. 

AIIKT.  .drir    Kl-rtr. ,: h>Tany  :ind  Rii'lioloL'y.   vol.   \x\vi,   No.  ;}.   March,   191S, 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  503 

For  neuritis  Do  Kraft1  applies  diathermy,  light  mild  wave  current, 
or  mild  resonator  effluve  by  bipolar  method. 

JVI.  L.  H.  Arnold  Snow2  in  the  treatment  of  neuritis  uses  the  static 
wave  current  lightly  and  only  as  a  palliative.  One  or  two  connected 
electrodes  are  applied  over  the  affected  part  for  twenty  minutes;  spark- 
gap  according  to  tolerance,  but  too  strong  will  aggravate  the  disease. 
x-Rays  are  applied  for  chronic  fibrous  conditions,  and  spinal  vibration  to 
relieve  muscular  tension.  Diathermy  is  applied  longer  and  with  slower 
heating  than  is  usually  advised. 

W.  B.  Snow3  claims  that  the  static  wave  current  in  neuritis  does  not 
irritate  acute  cases. 

De  Kraft,4  in  diathermy  for  neuritis  of  the  shoulder,  applies  one  large 
electrode  to  forearm  and  hand  and  another  terminal  to  the  De  Kraft 
chair  as  a  dispersing  electrode.  This  warms  the  whole  shoulder,  whereas 
if  applied  higher  up  the  current  would  pass  across  the  axilla;  300  ma. 
are  gradually  increased  to  1500  ma.  Then  he  uses  the  static  current, 
metal  plate  over  the  shoulder  and  |-inch  gap.  Later,  when  tenderness 
has  subsided,  he  applies  the  effluve  from  the  static  resonator. 

In  neuritis,  digital  pressure  and  the  static  wave  current  (Hirsh) 
should  reveal  tender  areas. 

A.  B.  Hirsh5  for  acute  neuritis  uses  an  incandescent  lamp  one  and 
one-half  or  two  hours.  (Burdick  lamp  made  in  Milton,  Wisconsin.) 
The  wave  current  makes  the  disease  wrorse  according  to  his  experience. 

For  a  neuritis  of  arm  and  shoulder  Martin  uses  the  static  wave 
current  over  the  brachial  area  with  smallest  spark-gap  as  a  test.  Static 
wave  current  followed  by  sparks  over  whole  plexus  and  down  arm  are 
used  for  treatment. 

Electric  Treatment  of  Neuritis. —  In  cases  of  neuritis  the  nerve  is 
usually  to  be  treated  by  galvanic  currents;  the  paralyzed  muscles,  by 
faradization  or  galvanofaradization. 

Sinusoidal  currents  may  be  applied  in  the  same  way  as  faradic  or 
galvanofaradic  currents,  and  often  succeed  in  cases  of  neuritis  where 
these  currents  have  failed. 

Cases  Simulating  Neuritis. — In  a  case  of  lancinating  occipital  pain 
palpation  showed  typical  small  fibrositis  nodules.  The  treatment  was  by 
the  static  wave  current,  radiant  light  and  heat,  and  vibration  (Hirsh6). 

Tremor  of  right  upper  extremity  with  neuralgic  pain  throughout 
left  brachial  plexus.  Sites  of  true  neuritis  could  not  be  located,  but 
indefinite  evidence  of  deltoid  fibrositis  with  possible  subacromial 
bursitis.  Galvanic,  +  forehead,  --  below  occiput;  radiant  light  and 
heat  with  the  static  wave  current  alternating  with  salicylic  ionization 
over  the  shoulder  for  brachial  plexus  and  over  deltoid  region,  all  were 
tried,  to  no  effect,  and  later  the  lesion  was  found  to  be  an  intracranial 
tumor. 

Static  Induced  Sparks  for  Neuralgia.-  These  are  applied  by  a  metal 
electrode  through  the  intermediary  of  a  static  regulator.  Direct  static 
sparks  are  also  useful. 

1  Amor.  Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi,  No.  3,  March,  1918,  p.  9. 

2  Ibid.,  March,  1018,  p.  96. 
'  Ibid.,  March,  1918,  p.  97. 
4  Ibid.,  March,  1918,  p.  08. 
6  Ibid.,  March.  1918,  p.  98. 

6  Ibid.,  No.  1,  January,  1918,  p.  1. 


.">04  MEDICAL    KLKCTR1CITY    AND    KONTCIKN    KAYS 

Trigeminal    Neuralgia. — The    most  persistent    of   all   the    neural- 

Lria-  of  the  face  is  that  known  so  widely  as  tic  douloureux.  This 
belongs  to  the  group  of  neuralgias  due  to  disease  of  the  sensory  gan- 
glion. It  differs,  somewhat,  although  not  always,  from  The  ordinary 
herpes  neuralgias  in  that  it  is  more  persistent,  more  severe,  is  usually  not 
a--ociated  with  paralvsis.  and  does  not  cause  an  herpetic  eruption.  This 
is  not  an  absolute  rule,  but  is  the  general  course  of  the  disease.  Any 
one  of  the  chief  branches  of  the  fifth  nerve  may  be  involved,  and  in  the 
more  protracted  case-  it  is  usual  to  find  that  all  the  distribution  of  the 
fifth  nerve  is  implicated,  and  in  the  chronic  cases  certain  trophic  changes 
usuallv  accompany  the  onward  progress  of  the  disease. 

Ordinary  faradie  or  galvanic  electricity,  more  particularly  faradic, 
is  practically  of  no  value  in  the  treatment  of  trigeminal  neuralgia,  save 
perhaps  in  the  very  early  stages.  The  principle  of  a  counterirritant 
does  not  apply  to  these  cases,  as  it  does  to  the  treatment  of  referred 
pains.  Certain  modifications  of  electric  treatment,  however,  have 
proved  of  service  in  this  persistent  form  of  neuralgia.  Thus  high- 
frequency  currents  and  high-voltage  currents  have  shown  themselves  to 
be  of  value,  and  the  treatments  advised  by  Bergonie  and  Leduc  have 
been  reported  as  efficacious.  Leduc1  has  reported  an  interesting  case 
in  which  he  has  been  able  to  apply,  by  the  method  of  cataphoresis,  the 
ions  of  quinin  with  permanent  relief.  The  case  was  that  of  a  woman 
sixty-eight  years  of  age,  who  developed  a  tic  douloureux  after  refrigera- 
tion. The  inferior  branch  alone  was  involved.  The  area  was  ex- 
quisitely tender,  and  the  slightest  variation  in  temperature  caused 
a  paroxysm.  She  was  unable  to  swallow  anything  cold,  and  even  the 
blowing  of  cool  air  upon  her  face  was  unbearable.  She  was  unable  to 
>leep.  her  teeth  were  sacrificed  to  no  advantage,  and  the  submaxillary 
nerve  was  divided  and  the  lower  jaw  resected  wit  hout  results.  Hichlorid 
of  quinin  in  1  per  cent,  solution  was  applied  electrically  for  half  an  hour, 
with  a  current  which  was  gradually  raised  to  20  ma.  This  gave  rise  to 
redne-.-  in  the  skin  and  edema,  but  there  was  a  marked  diminution  in  the 
pain,  and  the  patient  was  able  to  sleep.  A  second  application  was 
made  three  (lays  later,  since  which  time  'one  month  after  the  application) 
There  had  been  no  return  of  the  pain.  Leduc  has  never  given  The 
subsequent  history  of  this  case,  and  it  is  certain  that  to  report  such  a  case 
one  month  after  does  not  prove  the  permanent  efficacy  of  cataphoresis 
in  t  he  '  n-at  iii'-nt  of  1  his  affect  ion. 

Uergonie   has   advi-ed   a   method   of   applying   very   heavy    currents 

an.-  i  'l  electrodes  which  cover  t  he  em  ire  side  of  t  lie  face.      The  cur- 

•  '  '   i-  applied  in  as  large  doses  as  from  (ill  to  s()  ma.,  the  active  electrode 

elect  rode  covered    with   'lamp    wadding   or   clay)    beini:    the 

'•  pole,  and  bein'.:  very  accurately  fit  ted  to  the  surface  and  model- 

;::-  "i  ':.•    :  ici  .      The  duration  of  the  application  should  be  at  least  half 

•  "•/    fin'    T  r"!i  in  i  mil    \  i  nrnl'/in. —  Correct    Technic    is 

nt  when  applying  current  -  of  t  his  st  reiigth.  in  order  to 

>  or  burns.     The  elect  rode-  niu.-t   1,,.  large,  and  of 

'    I  lie  current    uill   be   uniformlv  distributed  over  all 

An  ordinary  -pon^e  electrode  often  ha-  one  or  more 

.'  in  :      '  i-  almo-t   directly  in  contact   with  the  -kin,  and 

iiivi    il«-  K]«-rr  rich  •'  Mci|ic:ilc.   I'.Mi  I. 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM 

consequently  practically  the  entire  current  would  puss  to  the  skin  at  a 
small  spot  and  produce  a  burn.  The  active  positive  electrode  is  made 
of  sheet  metal  fitted  to  the  shape  of  the  side  of  the  face,  and  \vith  three 
prolongations  extending  over  the  forehead,  the  upper  ja\v.  and  the 
lower  juw.  Felt,  clay,  or  kaolin  \vet  with  solution  of  sodium  bicarbonate 
prevents  any  metallic  contact  with  the  skin.  The  indifferent,  negative 
electrode  is  of  the  same  nature,  and  is  applied  at  the  nape  of  the  neck 
or  between  the  shoulder-blades.  A  rheostat  should  be  tised  to  turn  the 
current  on  and  off  extremely  gradually. 

A  continuous  current  of  as  much  as  (10  ma.  will  sometimes  succeed  in 
greatly  relieving  a  case  of  trigeminal  neuralgia  after  extraction  of  teeth, 
nerve  resection,  and  removal  of  the  (lasserian  ganglion  have  failed — and 
the  improvement  may  be  permanent. 

The  Method  of  Mild  Galvanization. — Three  to  twelve  milliamperes 
may  be  applied  for  an  hour  at  a  time  from  similar  electrodes. 

Distribution  of  the  Current  in  Applications  to  the  Fare. — The  heavy 
galvanic  currents  which  are  sometimes  applied  for  facial  neuralgia, 
either  for  the  effect  of  the  currents  themselves  or  that  of  the  medicinal 
ions  carried  by  the  current,  do  not  pass  in  a  straight  line  from  the  active 
electrode  to  the  nape  of  the  neck,  where  the  indifferent  electrode  is 
placed.  The  current  is  diffused  through  every  part  of  the  head  and  neck, 
but  is  of  greatest  density  along  paths  of  least  resistance.  It  passes  with  a 
practically  uniform  density  through  all  parts  of  the  skin  in  contact  with 
the  electrode,  and  also  through  muscles  and  fascia.  \Yhen  it  comes  to 
bone,  it  encounters  resistance  which  is  very  much  greater  than  at  the 
different  foramina  and  the  vessels  and  nerves  passing  through  them. 
The  greater  part  of  the  current,  therefore,  follows  these  important  struc- 
tures and  passes  through  the  (lasserian  and  other  ganglia  and  the  brain, 
cerebellum,  and  medulla. 

The  symptoms  observed  by  (lautrelet  (p.  401)  from  the  application 
of  similar  currents  in  rabbits  are  due  to  a  primary  stimulation  and  an 
ultimate  paralysis  of  the  nervous  system  along  these  conducting  paths. 

The  method  of  heavy  currents  for  long  applications  is  to  be  applied 
with  great  caution,  and  only  by  an  expert  physician.  The  following 
physiologic  effects  are  introduced  at  this  point  to  enforce  this  admoni- 
tion. 

Although  the  electric  treatment  of  trigeminal  neuralgia  is  of  great 
service,  particularly  in  the  milder  cases,  il  cannot  be  said  that  at  the 
present  time  any  sure  electric  method  is  known  for  the  very  severe 
cases,  and  one  must  sometimes  have  recourse  to  surgical  procedure.- 
which  have  been  advised.  Alcohol  injections  into  the  substance  of 
the  ( lassenan  ganglion  or  the  affected  branch  of  the  nerve  have  proved 
to  be  the  simplest  and  most  efficacious  method  of  treating  these  affec- 
tions. Such  injections  are  easy  of  application,  are  not  attended  by 
any  disastrous  by-effects,  and  the  experience  of  Schlosser,  Lew.  and 
others  shows  that  relief  may  be  sriven  for  yeats  at  least,  even  if  such 
injections  do  not  make  a  permanent  cure. 

1  /'<  </t tin  til  of  'I  /'K/I  tn  i  nnl  .\  i  a /'nl//in  !>//  j'-li'ii'/  n/i/l  hi/  II tt/Ji-t'i'i '/'/'  /"''/ 
('uri'(  itt*. — These  important  and  often  successful  methods  are  described 
on  pp.  f)!l3  and  1  1<»L>. 

Radium. — This  has  also  been  used,  but  without  lasting  success,  in 
the  cases  which  the  author  has  seen. 


506  MEDICAL    ELECTRICITY    AND    KOXTGEN    RAYS 

Static  Electricity  for  Tic-doukmreux.—  Win.  B.  Snow1  applies  the 
static  wave  from  a  metal  electrode  held  in  place  with  the  bare  hand  and 
-i— inch  spark -gap.  He  expects  a  cure  in  a  week,  and  uses  the  same  appli- 
cation for  neuritis  in  general. 

Cervicobrachial  Neuralgia. — Neuralgia  in  one  or  more  of  the 
brandies  of  the  bracliial  plexus  is  not  infrequent.  The  pain  is  usually 
felt  in  the  neck,  and  shoots  down  the  nerve-trunks  to  the  arm  and  fore- 
arm. Movements  of  the  arm  are  usually  very  painful,  and  the  hunched-up 
shoulder  and  half-carried  arm  are  characteristic  of  the  attitude  of  these 
patients.  The  most  frequent  causes  of  brachial  neuralgias  are  exposure 
to  cold  or  injury,  tumors,  and  poisoning  from  gout,  alcohol,  lead,  or 
syphilis. 

Brachial  neuritis  may  be  an  expression  of  a  greater  degree  of  injury 
in  the  nerves  at  their  origin  in  the  plexus,  or  somewhere  in  their  course. 
Here  the  pain  is  apt  to  be  more  severe,  th"  nerve-trunks  themselves 
become  tender,  and  trophic  changes  take  place  in  the  muscles,  the  skin, 
and  the  nails. 

The  deltoid  muscle,  for  reasons  as  yet  little  appreciated,  is  apt  to 
develop  a  deltoid  neuralgia  or  neuritis.  It  is.  as  a  rule,  a  mild  inflam- 
mation of  the  circumflex  nerve.  It  is  a  not  infrequently  annoying 
trouble  among  people  who  write  considerably,  and  may  perhaps  be 
classed  at  tini"s  as  an  occupation  neurosis.  It  is  a  not  infrequent  dis- 
order among  workers  with  the  broom,  and  is  seen  here  in  some  of  its 
more  severe  forms. 

In  the  diagnosis  of  the  site  involved  in  cervicobrachial  neuralgia  and 
neuritis  certain  additional  symptoms  are  of  value.  In  inflammations 
low  down  in  the  cervical  area,  involving  the  first  dorsal,  pain  over  the 
clavicle  is  very  marked.  Furthermore,  a  neuritis  in  this  region  is  apt  to 
involve  the  sympathetic  fibers,  which  have  a  relation  here  with  the  upper 
dorsal  .-elements  of  the  cord.  The  evidences  of  these  sympathetic  signs 
are  a  slight  retraction  of  the  eyeball;  the  lids  come  closer  together  on 
the  affected  side,  t  he  outer  angle  droops,  and  there  is  a  slight  contraction 
of  the  pupil  on  the  affected  side,  with  diminished  light  contractility. 
Some  cases  .-how  a  dilated  pupil  on  the  affected  side. 

Many  of  the  severe  cases  of  bracliial  neuritis  are  extremely  obstinate, 
per-i-tin^  at  times  for  months  rather  than  weeks,  and  they  tax  the 
therapeutic  resources  of  the  attending  physician. 

In  addition  to  ordinary  method-  of  treatment  by  rest,  salicylates, 
iron.  heat,  and  general  supporting  measures,  counterirritation  by 
means  of  the  actual  cautery  and  1  he  use  of  electricity  are  the  two  most 
sat  i.-fact'  iry  measures  to  employ. 

}•'.}••!•'>  }•'](•  current  -  are  harmful  in  t  lie  very  early  si  ages  of  the  affection, 
and  practicallv  the  onlv  form-  that  are  ot  service  are  the  direct,  high- 
frequency,  and  -iiiu.-oidal  currents.  Induction  current-  are  usually 
harmful.  I.\'i<']-e.  at  least  so  long  as  pain  is  present,  is  verv  prejudi- 
H; 


ELECTRICITY    IN    DISEASES    OF   THE    NERVOUS    SYSTEM  .)()< 

trunks  for  at  least  ten  minutes.  The  pole  should  be  shifted  from  time  to 
time,  but  not  removed  from  contact  with  the  arm. 

The  sinusoidal  arm  bath  is  of  value  when  the  pain  has  receded 
to  such  a  degree  that  the  pain  is  felt  only  on  movement.  High-fre- 
quency currents  are  often  beneficial  in  the  treatment  of  the  chronic 
painful  stagers  of  the  disease.  They  relieve  pain  greatly,  even  when 
they  exert  no  marked  effect  upon  the  course  of  the  neuritis. 

Intercostal  Neuralgia. — Bergonie's  method  of  covering  the  painful 
area  with  a  large  positive  electrode  and  applying  currents  of  50  to  SO 
ma.  for  half  an  hour  at  a  time  is  effective  here.  The  same  careful 
technic  is  essential  as  in  cases  of  trigeminal  neuralgia.  The  x-ray  is 
very  effective  in  these  cases.  Glass  vacuum  electrodes  from  the  Oudin 
monopolar  resonator  also  succeed  very  well.  A  local  electric-light  bath 
is  excellent,  producing  its  effect  chiefly  by  dry  heat,  and  if  the  skin  is 
slightly  blistered,  this  does  not  cause  pain. 

Sciatica. — This  is  perhaps  the  most  frequent  of  all  the  neuralgias 
of  the  body.  Lying,  as  it  does,  in  an  exposed  position,  the  sciatic  nerve 
is  subjected  to  frequent  stretching,  and  not  infrequent  chilling  and 
trauma.  It  is  a  medley,  in  reality,  of  conditions  rather  than  one,  and 
what  has  been  written  with  reference  to  the  occurrence  of  referred  pains 
must  be  borne  in  mind  in  all  cases  in  which  pain  in  the  sciatic  nerve 
distribution  is  found. 

As  a  referred  pain,  sciatic  neuralgia  is  frequently  found  as  a  result 
of  affections  of  the  prostate1  gland,  of  hemorrhoids,  of  fissure  of  the  anus, 
and  in  a  few  visceral  conditions  in  women  associated  with  retrodisplaee- 
ments  and  procidentia.  These  are  not  cases  of  true  sciatic  involve- 
ment, although  the  severity  of  the  pains  may  lead  to  such  a  diagnosis. 
In  much  the  same  way  chronic  hip-joint  affections  may  give  rise  to 
sciatic  pains. 

Pressure  on  the  nerve  from  chronic  constipation,  from  a  pregnant 
uterus,  and  from  tumors  is  to  be  borne  in  mind.  Chronic  progressively 
increasing  pain  in  the  sciatic  distribution  points  to  a  tumor  pressing 
upon  the  nerve-trunk  within  the  pelvis. 

Finally,  one  has  to  bear  in  mind  that  specific  hcrpetic  eruptions 
occurring  in  sciatica  point  to  inflammation  in  the  sensory  ganglion. 
These  cases  are  frequently  severe,  but  are  apt  to  recover  with  a  fair 
degree  of  rapidity. 

The  symptoms  will  vary  much.  The  referred  pain  sciaticas  are  not 
of  very  wide  distribution  as  a  rule;  those  due  to  herpes  may  involve 
most  of  the  branches.  The  true  perineuritic  sciaticas  vary  considerably, 
sometimes  involving  only  a  few  branches,  at  other  times  occupying  most 
of  the  entire  distribution.  The  agonizing  and  paroxysmal  nature  of  the 
pain  is  one  of  its  chief  characteristics.  It  is  usually  increased  by  move- 
ment of  any  kind,  and  more  particularly  so  by  all  those  movements  which 
call  for  hyperextension  of  the  nerve.  Tenderness  along  the  nerve-trunk 
is  usually  present.  It  is  apt  to  be  absent  in  the  referred  pain  sciaticas. 
As  a  rule,  the  pains  are  worse  at  night,  and  eventually  the  patient  is 
forced  to  limp  and  hold  the  limb  stiff,  frequently  giving  rise  to  a  distinct 
and  typic  posture,  with  a  resulting  deformity. 

So  far  as  electric  treatment  of  sciatica  is  involved,  it  should  be 
considered  purely  as  an  adjuvant,  although  high-frequency  current 
applications  and  those  of  Leduc's  low-tension  interrupted  current  are 


MKDICAL    ELECTRICITY    AND    ROXTGEX    KAYS 

often  of  immeeliate-  and  peTinanent  relief  in  a  number  of  the  most  in- 

t  ract  able  cases. 

In  the  referred  pain  sciaticas  counterirritat ion  by  the  faradic  brush 
or  the  static  bree/e  is  of  signal  service,  but  is  useless  in  the  severe  pe-ri- 
neuritic  cases. 

Heavy  constant  currents  are  valuable  for  their  sedative  effects. 
Laru'e  electrodes  should  be  used,  and  long  applications  are  necessary — 
o()  to  til)  ma.  for  from  ten  to  twenty  minutes — one  electrode  over  the 
iliac  fossa,  the  other  to  the  sciatic  nerve  in  some  part  of  its  course1. 
Both  ascending  and  descending  currents  should  be  tried,  since  the  deter- 
mination of  the  best  direction  of  the  current  has  been,  and  is  still,  the 
subject  of  considerable  controversy.  In  both  acute  and  long-standing 
cases  high-frequency  currents  are  of  very  great  service1.  They  seem 
to  have  most  value  in  cases  in  which  thickened  painful  nerve-trunks  are 
present.  Just  why.  is  not  known.  It  is  highly  injurious  to  attempt 
to  treat  sciaticas  e>f  the  perineuritic  type  too  early.  Absolute  rest  is  the 
first  requirement  if  one  would  avoid  the  chronic  infiltration  connective- 
tissue  changes  which  inevitably  lead  to  the  more  protracted  chronic 
forms  of  the  disease1.  Kven  the  use  of  the  constant  current,  which  is  the 
only  admissible  form,  should  not  be  begun  prematurely. 

Various  forms  of  the  sinusoidal  current  are  useful  in  the  subacute 
stages.  The  bipolar  bath  with  this  type  of  current  is  most  satisfac- 
tory. It  should  be  used  only  when  relief  follows  its  application.  If  such 
usage  provokes  pain,  it  is  wiser  to  delay  its  application. 

In  the  very  obstinate-  forms  it  may  be  assumed  that  adhesions  have 
been  formed.  These  may  frequently  be  diminished  by  the  use  of  high- 
frequency  currents  and  ultraviolet  ray  emanations.  The  results  in  some 
of  the  author's  cases  (p.  ~>M)  have  been  magic. 

Scidtica,  Snow1  says,  is  often  due  not  to  neuritis  but  to  a  dilated 
stomach,  consolidation  at  the  apex  of  the  lung,  enlarged  prostate, 
colonic  or  sigme>idal  impaction.  He  caused  the  disappearance  of 
sciatica  in  three  high-frequency  treatments  of  an  enlarged  prostate. 

Diagnosis:  When  radiant  light  and  heat  and  wave  current  for  three 
or  four  weeks  i  pat ient  not  allowed  to  exercise)  fail  to  decidedly  be-m-fit 
sciatica,  look  for  something  else.  .r-Uay  very  use-till  wlie-re-  there1  are 
tibroiis  adhesions  around  the  nerve,  often  due  to  sitting  on  hard  sub- 
stances. Alternate  with  electric  liirht.  Mild  treatment  two  or  thre-e 
times  a  week  'John  \\  .  Torbett '-'}.  The  static  wave  current  with  metal 
plate  may  be  used  to  locate  t ender  point s  by  pain  pmduced  at  t  he  site-  of 
t  lie  lesion.  In  1  he  arm,  placing  t  he  elect  rode  from  t  lie  clavicle-  backward 

r  the  scapular  region,  a  very  short  spark-gap  will  cause  severe  pain 

some   point;   this   i<   the  site  ot    the   lesion.       The  same   result    ocean's 

the   sciatic   notch    in   .">()   per  cent,   ot    sciaticas.      The  electrode'   is  4 

IH-S  ui.li-  and  1'J  indies  long,  and  extends  Ironi  the  sciatic  notch  up 
the  lower  third  of  the  quadratic  lumborum  museaV;  1',-inch 
excruciating  pain  at  the  sciatic  notch  it  the  lesion  is 
i.ain  is  elicited  over  both  sciatic  and  anterior  crural 
•-ion  is  intrapelvic.  \\ith  an  electrode  over  the  ne>tch 
ar  region,  if  there  are  lumbar  metastasis  or  Pott's  disease, 
treatments  will  aimravate  the  disease,  r-b'av  istheemlv 

\itii-r    .l-iui     1        tpithrr.-ipy  :iinl  l!:nlinlMi:y.    vol.    \x\vi.    N'n.    1 

; 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  509 

means  of  absorbing  local  hyperplasia,  but  it  takes  months  of  small 
doses. 

The  vibrator  is  of  the  greatest  use  in  locating  the  parts  of  Ihe  nerves 
requiring  treatment.  Then  the  static  wave  and  sparks  clear  up  the 
majority  of  cases.1 

Sciatica  and  neuralgia  of  front  and  outer  side  of  thighs  is  benefited 
by  static  wave  current  with  5x8  inch  metal  electrode  on  upper  abdo- 
men for  debility  and  poor  digestion  (Hirsh). 

Win.  Martin2  says  sciatic  neuritis  may  be  tested  by  the  static  wave 
current,  placing  the  electrode  first  over  the  sciatic  notch,  and  then  along 
the  course  of  the  nerve  and  its  branches.  Treatment  may  be  by  the 
wave  current  to  the  most  painful  areas,  followed  by  indirect  sparks. 

Remnant  of  pain  at  fibular  area,  static  induced  very  small  electrode 
over  the  head  of  the  fibula  and  a  larger  one  over  sciatic  notch.  Fairly 
large1  spark-gap,  one  pole  grounded. 

Sciatic  neuritis.  Wave  current  soon  lost  its  effect  of  hurting  and 
static  induced  substituted.  First  smallest  Leyden  jars,  later  quart 
size. 

Chronic  Sciatic  Neuralgia. — Galvanic,  Faradic,  and  Static  Applica- 
tion*.— Weak  Galvanic  Currents. — Eight  or  ten  milliamperes  may  be 
applied,  as  already  described  for  heavy  currents;  or  Benedikt's  method 
of  galvanization  of  the  sacral  plexus  by  a  metallic  electrode  in  the  rectum 
and  a  large  electrode  over  the  sacral  or  lumbar  regions;  an  electric  lavage 
may  be  used  instead  of  the  metallic  electrode  for  the  rectal  pole.  Farad- 
ization may  be  applied  by  sponge  electrodes,  one  over  the  lumbar 
region  and  the  other  over  different  painful  spots  and  the  affected  muscles; 
or  the  active  electrode  may  be  a  faradic  brush,  and,  if  so,  the  secondary 
coil  should  be  of  fine  wire,  to  avoid  muscular  contractions.  Static 
insulation  followed  by  static  sparks  along  the  spine  and  the  sciatic  nerve, 
and  static  induced  currents  are  all  useful. 

Static  Induced  Currents  for  Sciatica. — The  patient  is  not  insu- 
lated, and  holds  a  large  plate  electrode  connected  with  the  external 
armature1  of  the  positive  Leyden  jar  upon  the  skin  of  the  epigastric 
region.  A  small  metallic  ball  electrode  from  the  external  armature  of 
the  other  Leyden  jar  has  an  insulated  handle  by  means  of  which  it  is 
applied  to  the  skin  in  the  lumbar  region  over  the  emergence  of  the  sciatic 
nerve  from  the  vertebral  canal,  and  then  to  the  different  painful  spots 
without  breaking  contact  with  the  skin.  The  discharging  rods  of  the 
static  machine  should  be  separated  far  enough  to  produce  visible  con- 
traction of  the  lumbar  muscles  at  each  spark.  This  separation  will 
usually  be  less  than  half  an  inch.  After  ten  minutes'  use  of  the  negative 
electrode  the  connections  may  be  changed  so  as  to  make  the  positive 
electrode1  the  active1  one1.  A  static  bath  with  penvcrful  sparks  along  the 
lower  part  of  the  spine1  and  the  sciatic  nerve  may  be1  given  at  another 
treatment,  alternating  with  the  static  induced  current  treatment.  The 
best  results  .-ire1  obtaineel  frenn  daily  treatments,  and  De  Blois3  reports 
80  cure's  out  of  about  100  case's  tivate'el. 

1  Elizabeth  \Vripht,  Amor.  Jour.  Electrotherapy  and  Radiology,  vol.  xxxvi. 
No.  1 ,  January,  1D1S.  p.  7. 

-  AMHT.   Jour.    Klee'trothorapy   and   Radiolouy,   vol.    xxxvi,   No.   9,   September. 

191S.  p.  2t;:>. 

3  La  Presse  medicale,  April  10,  UK)."). 


510  MEDICAL    ELECTRICITY    AND    KONTCEN    KAYS 

Central  Mca*ur<  *  for  Sci<itic  Xeitralgia. — A  great  many  cases  require 
some  general  treatment,  dietetic  or  medicinal,  and  by  static  baths  or 
hydro-electric  baths  with  sinusoidal  currents,  without  which  the  local 
electric  treatment  may  fail. 

The  Mttfun!  of  Cali'anization  for  Acute  Caw*  of  Sciatic  Xeuralgia.* — 
This  is  applicable  from  the  very  first  moment  of  the  attack,  but  does  not 
succeed  so  well  after  the  case  has  become  chronic.  An  electrode, 
preferably  the  positive,  but  this  is  not  essential,  n'  by  7  inches  in  size, 
is  placed  over  the  upper  part  of  the  sciatic  nerve,  a  convenient  way 
being  for  the  patient  to  sit  upon  this  electrode.  The  other  electrode  is  a 
large  one.  bent  so  as  to  tit  around  the  calf  of  the  leg:  or  the  other  electrode 
may  be  formed  by  a  foot-bath  extending  up  to  the  ankle.  A  certain 
amount  of  glycerin  added  to  the  water  will  prevent  a  burn  occurring  at 
the  upper  surface  of  the  water.  Wearing  a  stocking  also  acts  as  a  pre- 
ventive. The  current  strength  is  to  be  from  30  to  50  ma.,  and  is  to  be 
applied  for  half  an  hour  to  an  hour — at  first,  every  day. 

The  prognosis  may  be  judged  of  by  the  results  of  the  first  few  treat- 
ments. If  this  treatment  has  been  begun  a  few  days  after  the  outset 
of  the  attack,  and  no  marked  relief  is  obtained  in  seven  treatments,  the 
case  is  probably  dependent  upon  a  constitutional  cause,  and  it  will  take 
several  weeks  to  effect  a  cure.  If  relief  is  prompt,  the  case  will  be  cured 
gooner. 

Galvanic  Current*  for  Sciatic  Xeuriti*. — There  is  the  same  arrange- 
ment of  electrodes,  but  the  application  is  much  weaker  and  shorter — 
only  s  or  10  ma.  for  about  ten  minutes.  The  positive  electrode  may  be  a 
roller  electrode  passed  over  the  different  muscles  which  are  painful  or 
show  trophic  changes. 

Of  recent  years  it  has  been  suggested  to  use  certain  remedies  which 
are  thought  to  have  an  effect  in  diminishing  the  proliferation  of  connec- 
tive tissues.  Such  a  remedy  as  potassium  iodid  has  been  used  for  years, 
and  with  a  certain  amount  of  success,  but  its  range  of  usefulness  is  very 
narrow.  More  recently  thiosinamin  and  fibrolysin  have  been  recom- 
mended in  the  treatment  of  conditions  accompanied  by  proliferation 
of  new  connective  tissue.  The  former  has  a  very  limited  range  of  appli- 
cation, but  the  latter  may  be  tried  in  some  of  the  chronic  cases  accom- 
panied by  thickening  of  the  nerve-trunks  when  other  remedies  have 
ceased  to  be  of  service.  Massage  in  combination  with  electricity  is 
fr<  (juently  of  value,  but  should  never  be  used  in  the  acute  or  subacute 
-taires.  that  is,  when  the  nerve-trunks  are  tender,  .lust  what  electrolytic 
lom/.ation  may  do  tor  the  perineurnic  sciatica-  i-  an  open  question. 

Surirical  procedures,  such  as  stretching  the  nerve,  are  hazardous, 
bul  dissection  and  actual  division  of  definite  adhesions  which  may  be 
found  and  longitudinal  splitting  of  the  nerve  has  been  practised  to  ad- 
vantage. 

Treatment  of  Lumbago  by  Faradization.— Sponge  electrodes  2 

•  it  the  vertebra1  and  t  he  other  shifted 
fine  wire  coil  with  very  rapid 
increased  as  toleration  is  estab- 
-  finishes  the  treat- 
once  or  twice  a  day. 

Electricity  in  Renal  Pain.      It   often  happen-  that   a  patient  who  is 

•  •    \\  I'ill,  Ji  >ur    <le  Phv-iot  iiernpM 


ELECTRICITY    IN    DISEASES    OF   THE    NERVOUS    SYSTEM  511 

sent  for  x-ray  examination  for  calculi,  and  in  whom  none  is  found,  will 
be  very  much  benefited  by  the  x-ray  exposure. 

Galvanofaradic  currents  as  strong  as  the  patient  can  bear  may  be 
applied  from  two  electrodes  about  4  inches  in  diameter,  placed  one 
in  front  and  one  behind  the  painful  kidney. 

Neuralgia  of  the  Testis. — This  is  treated  by  positive  galvanization 
with  as  strong  a  current  as  can  be  borne.  The  testicle  is  wrapped  in 
moist  cotton,  outside  of  which  is  lead-foil  connected  with  the  conducting 
cord.  The  negative  electrode  should  measure  4  by  5  inches,  and  is 
applied  to  the  lumbar  region. 

ELECTRICITY  IN  TREATMENT  OF  ORGANIC  DISEASES  OF  THE  CENTRAL 

NERVOUS  SYSTEM 

SPINAL  CORD 

The  chief  diseases  of  the  spinal  cord  may  be  grouped  as  those  due  to — 

(1)  Disease  of  the  motor  ganglia — poliomyelitis  type. 

(2)  Disease  of  the  motor  paths — lateral  sclerosis  type. 

(3)  Disease  of  the  sensory  paths — tabes  dorsalis  types. 

(4)  Diffuse  disease — myelitis  type. 

(5)  Intraspinal  disease — syringomyelic  type. 

Diseases  of  Motor  Ganglia. — Poliomyelitis;  bulbar  palsies  in  higher 
distributions;  chronic  atrophies  (Poliomyelitis  chronica),  mixed  types; 
amyotrophic  lateral  sclerosis.  The  chief  diagnostic  features  of  the  polio- 
myelitis syndrome  are  loss  of  tendon  reflexes,  muscular  atrophy,  trophic 
disturbances,  no  sensory  phenomena,  reaction  of  degeneration.  Grave 
forms  of  neuritis  often  may  be  confused  with  poliomyelitis,  but  the  pain 
element  in  the  former  affection  usually  suffices  to  make  a  differential 
diagnosis. 

Acute  Poliomyelitis — Infantile  Spinal  Palsy. — There  is  abundant 
evidence  tending  to  show  that  this,  of  all  the  affections  of  the  nervous 
system,  responds  with  marked  advantage  to  the  use  of  electricity.  There 
is  almost  no  time  following  an  attack  of  poliomyelitis  after  the  very 
acute  symptoms  have  passed  when  electric  treatment  may  not  be  of 
service.  The  ancient  dictum  that  if  reaction  of  degeneration  has  been 
present  for  at  least  three  months  regeneration  may  not  be  looked  for  is 
totally  false,  and  considerable  degrees  of  recoverability  may  obtain 
after  more  than  two  or  three  years  of  absolute  loss  of  electric  excitability. 

It  is  becoming  more  and  more  apparent  that  the  involvement  of  the 
ganglion-cells  in  poliomyelitis  is  extremely  irregular,  and  there  is  abun- 
dant evidence  tending  to  show  that  rarely  are  all  the  cells  in  the  nuclei 
supplying  the  muscles  equally  affected.  Thus,  notwithstanding  very 
severe  and  dee])  implication  of  a,  muscle  group,  many  of  its  fibers  are 
spared,  and  the  ganglion-cells  are  capable  of  stimulation,  with  retardation 
of  further  degeneration  in  the  muscular  fibers.  This  appreciation  that 
functional  muscle-fibers  are  often  retained  for  a  long  time  in  infantile 
paralysis  was  first  pointed  out  by  Duchenne.  of  Boulogne,  and  it  is  very 
easy  to  neglect  this  point  of  view  in  the  study  and  treatment  of  these 
cases.  Special  efforts  should,  therefore,  be  directed  to  the  cultivation 
of  these  residual  sound  fibers,  in  order  that  they  may  themselves  retain 
what  capacity  they  have,  which,  without  proper  physiologic  stimulus, 
would  inevitably  be  lost. 


MKDH'AL    KLF.rrHICITY    AND    ROXTGEN    HAYS 

The  more  extensive  the  nucleus  of  origin  of  any  group  affected  may 
be.  the  more  certain  it  is  that  sound  fibers  and  unaffected  cells  will  bo 
found.  It  is.  therefore,  of  irreat  importance  in  making  the  diagnosis  of 
any  u'iven  case,  so  far  as  electric  results  are  to  be  obtained,  to  boar  this 
definite  fact  in  mind.  Reference  to  the  cell  groups  in  the  cord  (see  p. 
404)  may  be  made  to  determine  this  point. 

In  general  it  may  be  said  that  the  grades  of  injury  in  acute  poliomye- 
litis are  at  least  threefold.  Certain  muscles  show  great  weakness,  but 
are  not  completely  paraly/ed :  react  ion  of  degenerat  ion  varies  within  the 
limits  of  t  he  muscles,  but  it  is  not  absolute  all  over;  trophic  changes  are 
not  present  to  any  marked  degree,  and  there  are  few  evidences  of  tem- 
perature changes  in  the  affected  member.  These  are  t  he  muscle  groups 
for  which  mild  exercise,  passive  movements,  and  massage  result  in 
ultimate  recovery,  but  there  is  no  doubt  that  electric  stimulation,  if  not 
begun  too  soon,  at  least  not  for  eight  to  ton  .veeks  after  the  onset  of  the 
paralysis,  will  hasten  the  recovery  very  distinctly.  Kven  after  years  of 
neglect  .Mich  muscles  maybe  helped  by  proper  electric  stimulation,  par- 
ticularly in  those  cases  in  which  the  reaction  of  degeneration  is  not 
marked  or  is  absent.  Cases  are  certainly  on  record  of  some1  ten  to 
fifteen  years'  standing  in  which  improvement  has  followed  the  electric 
treat  ment . 

A.-  for  those  patients  in  whom  complete  reaction  of  degeneration  is 
found,  less  can  be  done  by  electricity.  They  are  not  hopeless,  however, 
by  any  means,  and  a  marked  return  of  power  may  be  found  in  muscles 
which,  for  a  long  time,  have  shown  very  typic  reaction  of  degeneration, 
even  when  it  has  extended  over  a  considerable  period  of  time — even  as 
much  as  five  or  ton  years. 

In  the  treatment  of  these  cases  of  poliomyelitis  care  should  bo  taken 
not  to  commence  electric,  and  mechanic  treatment  as  well,  too  early. 
While  the  ganglion-cells  are  acutely  inflamed  it  is  harmful  to  excite  them 
elect  ricallv,  and  onlv  after  these  little  patients  have  been  at  rest  for 
a  period  of  from  eight  to  twelve  weeks  should  the  more  active  use  of 
electricity  and  forced  movements  be  begun.  In  some  cases  where  eon- 
tractures  have  a  tendency  to  come  on  early,  proper  orthopedic  proce- 
dure- and  the  -t  i m ula t  ion  of  antagonistic  muscles  mav  be  advisable. 

Th--  early  electric  treatment  should  not  be  be^un  so  long  as  there 
i-  any  tenderness  in  the  muscles  or  in  the  nerve-trunks.  The  presence 
of  pain  in  tin-so  patients  should  not  be  overlooked.  In  the  earlv  stages 
a  meningeal  m v< dvement . 

•eful   tests  are  made  and   the  n  suits  recorded,  each  muscle 
v-tem;it  ically  as  to  its    motor   point    and   its   muscle  sub- 
eiidori  react  ion.  t  real  ment 
mi-able   muscles.      The   <_i'a lvalue  am 
n  the  ca-e 

a  Ye    been 


KLK<  TKK  ITY     IX     IMSF.ASKS    OF    THK     NKUVOTS    SYSTF.M  51. 5 

fibers  commence  to  t;ike  on  normal  functions.     The  firsl   reactions  arc 
usually  those  in  response  to  the  induction-coil. 

The  static  wave  current  has  been  applied  for  a  profound  local  effect 
in  infantile  paralysis.  Electrode  of  22-gauge  soft  metal,  11  by  S  indie-, 
to  upper  half  and  lower  two-thirds  of  spine  alternately  for  twenty 
minutes  with  S  or  10-inch  spark-pip  from  S-plate  static  machine.1 

Kxem'xiny  Paralyzed  Muxdcx  !>//  Malic,  induced  Current. — The  large 
indifferent  electrode,  10  by  14  inches,  is  moistened  and  applied  to  the 
back.  Smaller  ones  are  strapped  to  several  different  affected  muscles 
and  all  connected.  Connections  are  made  with  the  outer  coats  of  the 
two  Leyden  jars.  Slow  speed  is  turned,  and  a  spark-gap  that  will  yield 
marked  but  not  painful  contractions  (HO  per  minute)  for  about  ten 
minutes. 

Light,  mechanical  vibration,  and  massage  are  also  used. 
Jones'  summary  represents  the  author's  position  so  thoroughly  that 
we  cannot  refrain  from  quoting  it  in  this  place: 

"In  every  case  of  infantile  paralysis  which  is  not  clearing  up  satis- 
factorily it  is  important  to  apply  electric  treatment,  continuing  it  for 
six  months  to  a  year  or  more. 

"  It  is  the  exception  for  a  muscle  to  be  so  completely  destroyed  by 
poliomyelitis  as  to  be  without  any  fund  ional  fibers,  and  these  remaining 
fibers  can  be  cultivated  by  persevering  st  imulat  ion  of  them. 

"  \\  here  the  muscles  show  only  the  reaction  of  degeneration,  or  even 
where  reactions  are  entirely  abolished,  some  improvement  may  be  hoped 
tor  in  a  good  percentage  of  cases. 

"The  amount  of  restoration  which  may  be  possible  in  a  muscle  wil1 
depend  upon  the  number  of  surviving  ganglion-cells.  \Yiih  prolonged 
treatment  recovery  advances  very  much  farther  than  one  might  expect, 
and  is  infinitely  superior  to  the  results  obtained  when  treatment  has  not 
been  given. 

"!•] ven  where  the  electric  reactions  are  not  altered  in  quality,  it  is  not 
U'ood  practice  to  leave  the  case  to  lake  care  of  itself." 

F.  K.  Peckham-  t  reats  anterior  poliomyelitis  a*  follows:  Wave  current 
over  lumbar  and  lower  dorsal  regions  for  the  legs;  or  upper  dorsal  and 
lower  cervical  if  the  arms  are  involved;  500  candle-power  lamp,  prefer- 
ably wit  h  blue  glass  screen,  over  back,  abdomen,  and  paralyzed  members 
twenty  or  thirty  minutes.  Later  add  sinusoidal  current  to  stimulate 
muscles  and  restore  tone,  also  vibration  applied  to  the  legs. 

\Y.  1).  Snow::  for  poliomyelitis  uses  radiant  light  and  heat,  static. 
high-frequency,  and  sinusoidal  currents.  For  these  cases  the  sinusoidal 
with  one  electrode  over  the  spinal  center  and  others  to  affected  parts  is 
better  than  to  two  ends  of  a  muscle. 

The  static  wave  current  has  been  regarded  by  Snow  as  very  val- 
uable in  loco/notor  afnxia,  spastic  paraplegia,  traumatic  injuries  of  the 
-pine,  transverse  myelitis,  pachvineningit  is. 

For  (iiriitiic  ('/:.-<(. -<  i>f  poliomyelitis  he  applies  a  static  wave  current 
\vithaspark-gap  1  foot  lone  and  a  sinusoidal  current  of  such  a  strength 
as  will  cause  gentle  contractions  on  the  sound  side,  also  high-frequency 
currents. 

1.  SHOW.  Jour.  Advance,!  Therm..  October.  I'.U'J. 

5.   March.    I'.Uv 


514  MEDICAL    ELECTRICITY    AND    UOXTGEN    RAYS 

Cfirnnir  r<>lioini/<litis — I'rot/n  ssi r<  Muscular  Atrojilii/. — This  is  a 
lar<:e  group  of  oases  of  varying  causation,  pathologic  change,  and  outlook. 
It  is  difficult  to  treat  them  all  as  one  disorder.  Two  general  typos  are 
to  be  differentiated— the  neuritic  and  the  central.  Irregular  reactions 
to  electric  currents  are  found  in  both.  In  the  ultimate  stages  of  com- 
plete atrophy  absolute  loss  of  electric  response  is  the  rule. 

The  results  of  electric  -treatment  in  these  atrophies  are  not  to  be 
viewed  in  an  oversanguine  light.  There  is  no  doubt  that  conscientious 
and  consecutive  t  reat  ment  will  ret  a  I'd  the  progress  of  1  he  atrophy. 

In  the  central  or  spinal  types  t-his  effort  is  rewarded  with  more  suc- 
cess than  in  the  neuritic  or  myopathio  forms.  Krb  has  recommended 
tin-  direct  application  of  the  galvanic  current  to  the  spinal  cord,  laying 
particular  stress  on  direct  electrization  of  those  segments  of  the  cord  in 
which  the  major  implications  are  to  be  found  —  usually  the  cervical  or 
lumbar  enlargements.  Jones  recommends;  the  use  of  the  induction-coil 
currents  in  mild  doses  in  these  cases. 

I'rai/ri  ssiri  Muscular  Atra/ili'/. —  1 1  vdro-eloct  ric  baths  with  triple- 
phase  currents  cured  a  case  reported  by  Albert-\\  oil. 

As  to  the  use  of  other  forms  of  electric  stimulation  in  the  chronic 
atrophies,  experience  is  not  yet  cumulative  enough  to  enable  one  to 
come  to  definite  conclusions.  High-frequency  currents  have  been  used 
by  a  number  of  observers,  among  whom  Denoyes  has  reported  good 
result-,  but  one  is  compelled  to  withhold  conclusions  in  the  cases  re- 
ported up  to  the  present  time. 

Disease  of  Motor  Paths  (Lateral  Sclerosis  T///H). — On  general 
principles  it  may  be  said  that  disorders  of  the  pyramidal  tracts  are  not- 
only  not  helped  by  electric  treatment,  but.  on  the  contrary,  are  harmed. 
I'p  to  t  he  pre.-ent  time  there  are  no  report.-  of  help  coming  to  these  cases. 
In  those  ca.-e.-  in  which  pressure  on  the  lateral  tract.-  by  tumor  causes 
the  affect  ion.  ./--ray  t  reat  ment  occasionally  diminishes  the  size  of  the 
tumor,  but  it-  u.-e  is  not  advisable  unless  surgical  intervention  is  abso- 
lutely impossible. 

In  multifilt  scli/'iisis  no  definite  progress  has  been  made.  Certain 
euros  have  been  reported,  but  the.-e  wen-  undoubtedly  cases  of  hysteria. 
It  is  well  known  that  multiple  sclerosis  has  periods  during  which  im- 
provement take.-  place,  only  to  have  the  patient  slip  further  back  at 
tin-  ni  .1  Ivaiice.  'svehot herapv  also  has  a  marked  value  in  helping 
•  ts  with  multiple  sclerosis  to  make  less  of  their  ills  than  is  their 
usual  uont. 

I  •  Main  advances  ought  to  be  made  in  the  electric  treatment  of  mul- 
tiple sclerosis  patients.  The  tissue  proliferation  is  of  a  type  which,  by 
.  should  be  affected  by  lilnh-frei  jiiency  currents,  just  as  we  know 
tic  inflammatory  oxudates  of  chronic  character  are 
::.'  ';:'.'•;.  Tip  field  is  not  hopeless  by  any  moans. 

Disease  of  Sensory  Paths  (Talus  l)nrsalis  '/'///»). — The  evidence 
i  >'  a  rn  'he  availability  ot  elect  rich  v  for  the  t  reat  men  1  of  disorders 

ot  tlii  •_  ••  ip  :  far  from  beinu  conclusive.  Much  depends  upon  the 
attitude  '.f  the  observer.  It  i-  admit  ted  t  hat  t  he  cure  of  t  rue  posterior 
l.eoj  advance,]  at  all  b\  any  vet  d.  vi-i  d  form  of  eloc- 
•'-'/.  I'am-  ma\  be  relieved,  minor  palsies  helped, 
cle-  improved,  and  the  function-  of  the  bladder 
I  i.  but  t  rue  tabi  -  dor.-ali-  ha-  not  yet  suc- 
cumb' '  '  .<  '  be  seen  uhv  1  i-  -,li\  !il.'  liln  >od  of  it-  dointr 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  515 

so.  Pseudotabes  of  neuritic  nature  following  poisoning  by  alcohol,  lead, 
aspergillus,  ergot  and  its  allies,  or  other  agents  causing  a  mild  ascending 
degeneration  may  recover  after  the  application  of  the  electric  treatment, 
but  it  is  not  even  certain  in  these  cases  that  the  neuritic  process  has  been 
hastened  in  its  repair  by  the  electricity.  These  pseudotabes  cases  re- 
cover after  treatment  by  almost  anything,  or  nothing,  and  hence  it  is 
of  little  profit,  to  argue  the  question  without  a  nrixon  d'etre. 

Application  of  Gnlvanic  Current*  to  the  Spine  in  Loconwtor  Atuxiri 
!>!/  M  <'<in*  of  Cell -bath*. — The  patient,  may  be  seated  in  a  perineal  bath, 
which  forms  the  positive  electrode,  while  both  forearms  rest  in  baths 
which  are  connected  with  the  negative  pole.  A  galvanic  current  of  25 
to  ;•>()  ma.  is  gradually  allowed  to  flow  for  about  ten  minutes.  The 
treatments  are  given  three  times  a  week  for  four  to  six  weeks.  All  the 
current  passes  through  the  patient  's  body,  and  according  to  the  rule  by 
which  currents  travel  chiefly  by  the  best  conducting  path,  we  know 
that  a  large  proportion  of  it  traverses  the  spinal  cord.  Allan!  and 
Cauvy,1  who  suggested  the  above  technic,  believe  that  a  favorable  effect 
may  be  exerted  upon  the  hyperemia  and  the  sclerosis,  and  especially 
the  lightning  pains  and  the  transitory  paralysis  of  the  early  stages  of 
the  disease  may  be  benefited. 

Vexic/il  Crixcs  in  Locomotor  Ataxifi.  Treatment  hi/  Gali'rnric  Cur- 
rent*.— The  bladder  is  filled  with  boric  acid  solution,  and  a  negative 
urethral  electrode  is  introduced  into  the  bladder.  A  large  positive 
electrode  is  applied  over  the  lumbar  region,  and  a  current  of  40  ma.  is 
gradually  turned  on  and  allowed  to  flow  for  fifteen  minutes.  Treatments 
are  given  twice  a  week. 

Can  it  be  claimed  that  electric  treatment  will  delay  the  progress 
of  a  tabes  case?  In  view  of  the  great  chronicity  of  the  affection 
and  its  irregular  course,  particularly  its  long  periods  of  non-progres- 
sion, it  is  hazardous  even  to  claim  this  for  electric  treatment  in  this 
disease1. 

The  last  word,  however,  has  not  yet  been  spoken,  and  it  will  be  pre- 
mature to  negative  on  a  priori  grounds  some  new  claimant  to  thera- 
peutic honors.  It  is  certain  that  the  radium  treatment,  .r-ray  treat- 
ment. Finsen-light  treatment  have  thus  far  disappointed  their  advo- 
cates. 

The  requisites  for  proving  the  claims  are  extremely  severe,  in  view 
of  the  many-sided  character  of  this  affection. 

The  x-Raij  and  High-frequency  Current*  A]>j>!i(d  to  the  Spine  in 
Lorotnotor  Ataxiu. — The  author  has  seen  great  lasting  improvement, 
though  not  a  cure,  in  a  case  which  was  also  treated  by  mercurial 
injecl  ions. 

Diffuse  Spinal  Disease  (.\fi/eliti*  Types).  —  In  those  patients  in 
whom  the  paraplegia  is  spastic  \ve  cannot  look  for  much  relief  from 
electric  treatment,  but  in  the  ataxic  types  associated  with  lost  knee- 
jerks,  in  which  involvement  of  the  gray  matter  seems  evident,  the  indi- 
cations for  electric  therapy  are  somewhat  similar  to  that  already  con- 
sidered in  the  Progressive  Muscular  Atrophies.  Certain  of  the  ataxic 
paraplegias  are  much  benefited  by  the  judicious  and  persistent  use  of 
both  galvanic  and  faradic  currents. 

Intraspinal  Disorders    (Ryringomyclin    Tu/n  ).—  It  is  a  curious  fact 


fllti  MKIMCAL    KI.r.CTKICITV    AND    HiiNTiiKN     KAV> 

that  of  all  the  disorders  of  tli"  spinal  cord  \vhicli  would  sccin  to  offer 
thf  least  hope  for  hfiit-tit  from  electric  t  n-at  nient .  syriiiii'omyelia  should 
be  one  in  uhidi  -udi  treatment  has  been  followed  by  definite  and  unmis- 
takable -iii'Ms  of  bet  ternietit .  llaviiiond  has  reported  the  iM>od  effects 
of  .r-ray  t  feat  men  t  in  a  number  of  cases.  The  pain-  have  been  stopped, 
the  pro^fe.—  of  the  atrophies  delayed,  and  other  si<rns  of  improvement 
indicated  a  regression  in  the  tissue  proliferation  in  the  syrimromyelia 
urea.  Kxperiences  of  this  are.  up  to  the  present  time,  too  irai:- 
mentarv  to  permit  of  wider  generalization,  but  the  results  in  the  cases 
reported  have  been  st  rikini:.  This,  taken  into  consideration  with  the 
wdl-known  conservatism  of  the  reporters,  should  be  sufficient  to  en- 
courage furtlier  investigations  aloim  this  line. 

Funiculitis  (inflammation  of  the  tissues  around  roots  of  the  spinal 
nerves1  is  treated  by  radiant  li»iit  and  heat  and  vibration.  Static 
sparks  to  relieve  muscle  spasm  iA.  B.  HirschM. 

BRAIN 

The  most  important  organic  brain  affection.-  here  to  be  considered 
are  brain  tumors  and  brain  hemorrhages,  resulting  in  the  hcmiplogic 
and  diple-ic  syndromes.  The  most  striking  <>f  these  are  the  infantile 
cerebral  palsies  and  the  adult  hemiple<rias. 

A  definite  decision  concerning  the  utility  of  electricity  in  organic 
affect  ions  of  the  brain  cannot  yet  be  reached.  Although  various  ob- 
servers have  been  u.-iiiLi;  all  types  of  currents  for  years,  and  some  are 
extremely  enthusiastic  as  TO  what  electricity  can  do  in  this  class  of 
affections,  the  more  conservative  and  careful  observers  approach  the 
matter  \vith  considerable  reserve.  Kxtravajrant  claim.-  would  border 
on  diarlatani.-m.  but  it  were  equally  as  fal.-e  to  common  sense  to  say 
that  what  we  now  know  is  of  no  service,  and  even  to  maintain  that  all 
t  hat  may  be  learned  i-  bound  to  be  fut  ile. 

P>ii'  not  'n  deal  in  futures,  it  i-  sufficient  to  make  the  general  con- 
f'-  — ion  of  faith  that  our  pre-ent  standpoint  i-  that  electricity  mav  be 
an  e\tre!iid\-  iin  j  iort  ant  adjunct  to  our  therapeutic  resources,  if  not  the 
ent  in  -uiirci  of  r>  liance. 

Hemiplegia.  In  the  organic  hemiple^'ias  n  should  be  borne  in  mind 
thai  ':.•  :,'-'  motor  neuron  i-  involved.  We  cannot  expect  bv  electric 
01  nil  111  :  -  to  obtain  the  regeneration  of  the  libel's  in  the  affected 
corti'i  path.  The  injury  done  liere  is  more  or  less  inevitable  and 

'.:.':.'  I' he  spinal  peripheral  motor  pat  h.  however,  is  unaffected, 

•  place  in  the  musde.-,  bones,  and  blood-ves- 

-1  .  -  oi  ;  'n.  pa  raly/ed  hinb  are  t  he  result  not  oi  an  v  real  inherent  affect  ion 
:  i  in  n-.  but  of  the  lad;  of  phy-iolo^ic  functioning 
in  t  h>  ;  iai  i  of  the  pa!  h. 

1'  i-.  ':.•  '•  ion  ,  evident  that  persistent  regard  paid  to  the  unmodified 
..'•'  I-  ab-olutel\-  essential,  and  one  linds  in  the  use 

•    !'\     help!  Ill    t  herapelll  lc    resolil'ci    .        (lid    hellli]  )l('»'ic 

;'•  treatment   or  treatment   bv  mas-au'e  bee,, me  more 
bui    b\    means  ol     ml  muscular  n'/mnast  ics. 

Lial'.'anic  and  farad ic  current.-,  a  ureal  amount  of  improve- 


KLKCTKH'ITY    IN    DISEASES    OF    THE    NEKVOVS    SYSTEM  517 

merit  may  be  brought  about.  This  improvement,  however,  will  not 
pass  beyond  a  certain  point,  and  just  how  far  such  treatment  may  In- 
effectual depends  upon  the  individual  case:  general  laws  cannot  be  pos- 
tulated. 

For  the  prevention  of  the  development  of  rigidity  the  use  of  both 
the  faradic  and  galvanic  currents  is  beneficial.  After  rigidity  has  set  in 
and  has  been  present  for  a  number  of  years  the  results  are  less  valuablt — 
in  fact .  massage  is  t  hen  more  serviceable. 

Ti'intnmii  of  Ilcn/i />l<'</iu. —  Begin  passive  movements  of  every  articu- 
lation from  the  very  (lay  of  the  stroke.  This  will  prevent  arthritis,  the 
deformed  attitudes,  pain,  and.  in  a  great  measure,  the  muscular  con- 
traclures  which  make  the  sequela1  of  an  apoplectic  stroke  so  much  worse 
than  would  be  the  case  if  the  condition  were  simply  that  of  paraly.-is  of 
certain  muscles.  Reeducation  of  voluntary  motion  is  to  be  begun  as 
early  as  possible.  Electricity  may  be  useful  in  the  treatment  of  atrophy 
of  certain  groups  of  paralyzed  muscles,  but  nut  for  general  application 
to  the  whole  hemiplegic  side  of  the  body. 

The  electric  treatment  of  hemiplegic  cases  should  be  begun  only  after 
the  acute  symptoms  of  the  paralysis  have  tullv  developed — that  is,  in 
from  foui'  to  six  weeks  after  the  init  ial  lesion.  As  pain  is  rarely  an  accom- 
panying symptom  of  hemiplegia,  t  his  does  not  have  to  const  it  ut e  a  com- 
plication. The  improvement  in  the  hemiplegic  cases  usually  comes  on 
more  or  less  rapidly — in  some  cases  almost  immediately.  The  galvanic 
currents  are  best  applied,  the  direction  being  that  of  the  course  of  the 
motor  tract,  namely,  from  the  spine  outward.  The  anode  is  placed  along 
1  he  spine,  and  t  he  cathode  at  the  periphery,  the  anode  being  moved  si  owl  v 
up  and  down  without  being  raised  from  the  skin.  The  electrode  should 
be  of  medium  sixe.  and  the  duration  of  the  application  should  be  from 
ten  to  twenty  minutes,  and  should  be  made  at  least  three  time?  a  \veek- 
preferably  daily. 

There  are  those  who  maintain  that  a  certain  amount  of  stimulation 
of  the  brain  itself  may  be  brought  about  bv  the  use  of  the  more  care- 
fully graded  currents  of  Leduc.  In  the  treatment  of  aphasia  a  certain 
amount  of  success  ha.- been  claimed  by  certain  1  rendi  investigators. 
The  application  should  be  made  i>y  the  alternating  current  of  low  in- 
tensity and  slow  interrupt  ions,  and  should  not  be  of  more  than  five 
minute.-'  duration  at  one  time,  while  care  should  be  taken  in  ascertain- 
ing the  re.-istance  of  the  brain  tissues  to  the  interrupted  current.  This 
subject  will  be  discussed  more  fully  in  a  separate  paragraph,  under  the 
capt  ion  of  Fleet  ric  Sleep. 

Infantile  Cerebral  Palsy. — The  indi\idual  lesion  which  may  be 
present  m  this  type  of  affection  varies  so  widely  that  we  cannot  in  this 
place  attempt  to  outline  the  symptomatology  of  the  group.  Suffice  it 
to  say  that  the  chief  damage  is  done  to  the  cort  icospinal  neuron,  and 
may  manifest  itself  in  monoplegia.  hemiplegia,  or  diplegia.  In  the 
monoplegic  types  nature  herself  does  much  to  minimize  the  damage 
done,  and  great  improvement  in  the  functional  capacity  of  the  affected 
muscles  may  be  looked  fur  Jrom  her  unaided  efforts.  Both  massage 
and  electricity  should  be  utili/ed  early  in  the  treatment  of  these  para- 
ly/ed  children.  The  indications  are  precisely  the  same  as  those  which 
have  been  already  spoken  of  in  t he  paragraph  on  lit  miplegia. 

It  is  to  be  borne  in  mind  that  the  lesions  in  infantile  cerebral  palsy, 
when  not  due  to  a  generalized  encephalitis,  are  of  the  hemorrhagic  type. 


MKDICAL    KLKCTHK  ITY    AND    RoXTCF.X    RAYS 

anil  that  functional  losses  arc-  much  more  extensive  than  the  primary 
anatomic  defect.  It  should,  therefore,  he  the  aim  of  the  electric  thera- 
peutist to  minimi/e.  so  far  as  possible,  the  teiulency  to  the  continuance 
of  this  functional  defect  until  the  time  when  the  exercising  of  the  hemor- 
rhage area  would  of  itself  bring  ahout  an  improvement  in  the  condition 
as  to  movement.  Both  galvanic  and  faradic  currents  will  prove  of 
service,  these  currents  beinir  useful  for  the  maintenance  of  nutrition. 
The  use  nf  massage  in  conjunction  with  the  electric  current  should  not 
he  lo.-t  siu'ht  of.  the  two  mutually  assisting.  Some  students  have  ob- 
tained  a  like  stimulation  of  muscular  tone,  and  nutrition  hy  the  use 
of  high-freiuiency  currents,  induction  discharges,  and  static  breezes. 
The  latter,  however,  are  more  useful  in  maintaining  skin  nutrition  than 
they  arc'  in  affecting  the  muscular  tissues  beneath. 

New  Growths  in  the  Brain. —  Here  the  symptomatology  is  so  varied 
that  wo  must  refer  the  reader  to  works  on  neurology.  What  can  be 
expected  of  electricity  in  the  treatment  of  new  growths?  It  must  be 
confessed  that  it  is  not  hy  any  means  clear  that  the  electric  treatment 
of  new  growths  is  of  much  service,  and  this  is  not  the  place  to  consider 
what  radium  emanations  or  ultraviolet  rays  may  do  for  certain  forms 
of  intracranial  growth.  In  view  of  certain  recent  results  obtained  in 
the  treatment  of  syringoniyelia  by  the  use  of  .r-ray  and  by  ultraviolet 
liidit .  it  cannot .  on  a  /irinri  grounds,  be  stated  that  similar  types  of  tissue 
degeneration  in  the  brain  may  not  be  beneficially  treated  with  this  form 
of  electrically  produced  energy. 

Manifestly  surgical  procedures  are  those  best  adapted  for  the  treat- 
ment of  intracranial  growths,  but  in  view  of  the  Bloomy  outlook,  even 
under  the  best  of  conditions,  research  in  the  matter  of  the  treatment 
of  growths  by  different  types  of  electric  energy  should  not  falter. 

Epilepsy.  It  seems  unnecessary  to  repeat  that  epilepsy  is  not  the 
name  of  one  diseasr — there  are  several  different  epilepsies.  That  the 
motor  discharge  induces  the  familial'  picture  is  true,  but  the  causes 
of  the  motor  di-charge  vary  from  slight  emotional  excitement  to  actual 
anatomic  destruction.  It  seems  incredible  that  electric  action  could 
affect  anatomically  altered  brain  tissue  to  such  a  degree  that  the  epilep- 
tic discharge  could  be  modified,  and  such  is  the  general  experience  of 
those  who  have  t  ried  electric  methods  in  the  treatment  of  epilepsy,  (lood 
ob.-ep.-i  rs,  -uch  as  Althaus  and  Krb.  have,  however,  reported  beneficial 


irn  til  being  passed  for  one 
anui  |e  occii  j  >ving  l  he  mi.  (i 
placed   over   the   occiput,  and  the  same  tvpe  of  ctir- 
ir  ;  he  same  lengt  h  of  t  ime. 

'hni  nl.-    have    been     reported    to    have   been    of    benefit     in 

'    l.-  conceivable  that    such   treatment    has  had  an  effect 

i'o  •  ;h  which  had  been  the  primary  cause  of  the  irritation 

i  I  he  motor  discharge.      (  >ne  cannot .  however,  pin 

mea.-'Ures.       They   should   be   adopted   as  expedients 

yel   in  a  position  to  maintain  that   they  should  be 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM 
GENERAL  NERVOUS  DISORDERS 

Of  the  more  general  nervous  disorders,  irregular  forms  of  muscular 
spasm  may  be  considered.  So  far  as  habit  spasms  and  tics  of  various 
types,  including  the  tic  of  torticollis  or  wryneck,  are  concerned,  it  seems 
certain  that  electricity  is  of  very  secondary  value.  In  most  of  the  habit 
spasms  the  psychic  element  is  very  strong,  and  electricity,  instead  of 
being  of  service,  usually  tends  to  aggravate  the  ills  that  are  already 
there.  Those  forms  of  spasm  or  tremor  or  irregular  tonic  or  clonic 
movements  which  are  of  an  organic  nature  due  to  minute  alterations  in 
the  vascular  supply  of  the  central  nervous  organs,  also  resist  electric 
treatment. 

So  far  as  the  cases  of  wry  nock  and  of  forced  irregular  posture,  which 
are  duo  to  exposure  to  cold  and  muscular  or  neuromuscular  involve- 
ment tiro  concerned,  electric  treatment  is  par  excellence  favorable.  Here 
the  faradic  cm-rent,  or  more  particularly  the  static  breeze,  or  induction- 
coil  sparks  are  of  groat  service. 

Chorea. — Treatment  of  chorea  by  electric  energy  remains  a  terra 
incognita  in  neurology.  Certain  cases  of  chorea  are  undoubtedly  much 
benefited  by  electricity,  especially  by  the  static  breeze,  or  application 
of  induction  sparks  to  the  spinal  cord,  or  galvanic  baths;  but  the  action 
is  probably  due  entirely  to  the  tonic  effects  on  the  body. 

Cases  of  chorea  treated  at  St.  Bartholomew 's  Clinic  have  been  quickly 
cured  by  the  application  of  glass  vacuum  electrodes  from  the  Oudin 
resonator  along  the  spine  and  over  the  upper  and  lower  limbs. 

If  it  be  assumed  that  most  choreas  are.  after  till,  the  results  of  a  post- 
infectious  toxemia  having  a  special  predilection  for  the  motor  area, 
causing  excessive1  irritability,  or  bringing  about  insufficient  inhibition, 
thru  it  is  comprehensible  why  general  electric  stimulation  by  the  static 
currents  is  as  efficacious  as  it  is  at  times.  Furthermore,  in  the  treat- 
ment of  exhaustion  states  following  excessive  choreic  movements  elec- 
tricity is  of  inestimable  value  and  should  be  added  as  an  adjunct  in 
the  treatment  of  this  affection  by  the  ordinary  tonic  measures  usually 
carried  out.  Pharmacopeal  therapy,  hydrotherapy,  and  electric  therapy 
combined  give  better  results  than  any  one  alone.  Jones  has  found 
in  the  treatment  of  these  cases  that  the  application  of  the  negative 
breeze  to  the  spine  is  a  convenient  and  more  agreeable  method  of 
treatment  than  the  ordinary  static  spark  procedure.  An  .r-ray  ex- 
amination of  the  teeth  frequently  reveals  dental  infection  as  the  cause 
and  points  the  way  to  a  cure  of  the  disease. 

Occupation  Neuroses. — These,  as  has  already  been  said,  are 
properly  considered  in  the  light  of  a  complex  etiology.  They  are 
cases  of  neurasthenia  mixed  with  a  bad  psychic  habit,  and  experience 
shows  that  in  their  treatment  they  are  extremely  obstinate.  As  is 
well  known,  such  forms  of  occupation  neuroses  associated  with  (•ramp- 
like  conditions  in  the  muscles  are  common  accompaniments  to  piano 
playing,  violin  playing,  tennis  playing,  and  tailors,  shoemakers,  and 
writers  are  often  afflicted  with  it.  A  vast  number  of  neuroses  belong 
to  this  group. 

Klect ric  treatment  is  of  service  undoubtedly  in  the  toninir  up  of 
the  muscles  themselves,  but  it  is  more  than  doubtful  whether  it  ever 
reaches  the  psychic  factor  in  the  disorder.  Our  own  experience  ha- 
been  very  disheartening  in  the  electric  treatment  of  these  occupation 
neuroses,  especially  writer's  cramp. 

(idlrnnir  Currents  for  Writer's  Cramp. — A  large  negative1  electrode 


MKlMeAL    KI.KCTHK'ITY    AND    UONTGEN    KAYS 


is  placed  between  the  shoulder-blades  and  the  forearm  rests  in  a  bath 
of  tepid  water  in  which  the  positive  electrode  is  placed.     A  current  of 

•SO  ma.  is  applied  for  fifteen  or  twenty  minutes  every  day. 

Exophthalmic  Goiter,      ('mil  the  exact  pathology  of  this  disorder 
i-  placed  upon   a   more   rational   foundation   it    were  futile  to  claim  for 
ii   that   it   may  lie  cured  l>y  electric  measures  of  treatment.      There  are 
hers  of  cases   in   which   electric   application-  of  the   induction   cur- 
rent applied  to  the  >ide-  of  the  neck  have  proved  to  be  of  considerable 
Thr-e  are  probably  those  cases  in  which  the  uoiter  is  largely 
d  [i    to  disturbances  in  the  functions  of  the  cervical  sympathetic  nerves, 
the  electric  treatment   serves  to  restore  in  part   at   least   a  function 
which  has  been  greatly  altered  bv  t  he  toxemia  of  t  he  overact  in <i  thyroids 
at  hvruids.     . \ppli cat  ions  to  t  he  glands  themselves  have  been  made 
inishinir  the  amount  of  "ilandular  substance  secreted  and 
11  ini   .  the  circulation.      Whether  electrolysis  can  brim:  t  his  about . 
a-  •  :.-  been  clainieil  by  a  number  of  observers,  is  highly  doubtful.       At 
any  rate,  th'1  i|Ue-tiiin  mu-t  remain  an  open  one  until  more  is  known  of 
'  hi-  disorder.    When  it  is  recalled  1  hat   I  )ubois.  of  He  rue.  reports  the  curt1 
number  of  cases  by  the  use  of  psycho! herapeutic  principles,  it  is 
:.<   '"--an"    to    realize    the    psvdiic    element    in    producing    the    anxiety. 

•  at  ion  phenomena  in  t  he  <  lisorder. 

The  electi'odes   may  be  placed   at    the  sides,   of  the  neck  behind  the 

•  n-.il'  -  of  the  jaw  with  the  negative  elec'rode  upon  the  side  of  the  most 

;ed   exopht lialmos ;    or   the    negative    electrode    may    be    placed    at 

ucha   and   :h"  anode  first    over  one  carotii'i   region  and  then  over 

•i,.'  other. 

A  not  her  successful  wav  to  use  t  he  galvanic  current  in  this  condition 

:-  to  apply  an  electrode  to  each  -ide  of  t  he  irland.      The  electrodes  should 

\\'et    in  a  solution  of  bicarbonate  of  soda  and  the  current 

;  b"  applied  for  fifteen  minute-  a  I  a  t  ime.  u.-inii  from  10  to  1~>  milli- 

rcs.      Th"  treatment   can  be  applied  twice  a  week.     Osier  advises 

a  thorough  trial  "t'  the  galvanic  current   for  three  or  four  months.      The 

direct  apphcat  loii  , ,|  ;l  -.park  t rom  a  -t at  ic  machine  has  also  been  of  ^reat 

service,  but.  of  course,  it   is  rather  a  disagreeable  method  of  treatment. 

\\  h'-n  this  is  used  the  patient  is  placed  on  the  insulated  platform  in  the 


• 


KLKCTKIC1TY    IN    DISKASKS    OF    TI1K    NKKVoFS    SYSTKM  ")21 

l)rass  hall  elect  rode,  which  is  held  in  the  hand  of  ihe  op:  rat  or,  is  brought 
\vii  hin  4  or  5  inches  of  the  other  end  of  the  spark  director,  when  a  spark 
\vi!l  jump.  This  is  rather  a  severe  treatment,  but  some  case-  have 
been  great  ly  benefited  by  it . 

Treatment  by  the  .f-ray  and  high-frequency  currents  has  resulted 
in  a  certain  percentage  oi  pernianeni  cures  in  the  author's  cases. 

Hysteria. — The  attitude  assumed  on  this  question  is  a  more  or 
less  radical  one.  It  is  highly  important  in  the  first  place  to  distinguish 
between  hysteria  proper  as  a  well-defined  and  carefully  described 
psychoneurosis,  and  hysteric  or  hysterifonn  symptoms  which  may  be 
the  accompaniment  of  a  vast  number  of  organic  affections,  not  only 
oi  the  central  nervous  svstem  but  also  the  entire  bodv. 

A  characteristic  feature  in  true  hysteria  is  a  certain  foundation  in 
character  which  permits  of  the  ready  dissociation  of  the  personality, 
and  it  is.  therefore,  characterized  by  great  emotional  instability  and  a 
childish  development,  stamping  the  individual  at  once  as  a  being  more 
primitive  than  the  education  and  environment  would  seem  to  show:  in 
other  words,  the  true  hysteric  character  is  a  primitive  character,  and 
it  is  well  recognized  that  true  hysteria  is  much  more  prevalent  among 
primitive  people-,  such,  for  instance,  as  i  he  natives  of  Java. 
Kraepelin  has  made  a  thorough  study,  the  Alueriean  negro,  am 
tvpes.  The  hysteric  character  is  never  altered  by  electricity. 
manifestations  of  the  dissociation  in  consciousness,  such  as  the 
paralysis,  anesthesias,  etc..  are  very  frequently  relieved  by  the 
electric  currents,  particularly  those  of  a  painful  or  shock-like  nature. 
Those  forms  of  energy  are  useful  which  make  sudden  unexpected  de- 
mands upon  the  attention  of  the  individual,  and  which  for  the  time.  To 
use  Janet  's  phrase,  are  capable  of  rousinu  the  nervous  tension  to  such 
a  point  that  the  dissociated  element  in  consciousness  is  brought  back 
into  the  hierarchy  of  the  conscious  personality.  With  the  cessation  of 
the  treatment,  however,  disaggregation  takes  place  in  another  asso- 
ciation, other  symptoms  arise,  and  the  fundamental  features  of  the 
personality  remain  untouched.  In  fact,  the  wonder-working,  -is  it 
were,  of  the  electric  display  only  contributes  to  the  receptivity  of  the 
individual  to  certain  classes  of  impressions,  which  rend  to  perpetuate 
the  primitive  nature  of  the  individual  instead  of  affording  any  means 
of  education.  If  the  electric  treatment  is  used  only  as  a  means  to  an 
end.  an  attempt,  as  it  were,  to  first  gain  ihe  attention  of  a  very  loosely 
aggregated  personality,  which  is  then  worked  upon  by  proper  psycho- 
therapeutic  measures,  then  its  use  may  be  advisable,  but  as  pure  elec- 
tricity it  works  to  the  disadvantage  of  the  individual.  The  galvanic 
or  faradic  treatment  of  hysterically  paralyzed  limbs  is.  we  believe, 
verv  harmful  to  the  individual.  The  element  of  suggestion  that  the 
limb  is  paraly/ed  by  the  incessant  working  over  it  by  electricity  tends 
to  perpetuate  the  paralysis  and  may  make  it  permanent. 

On  the  other  hand,  so  far  as  the  treatment  of  hysteric  xi/tnptonix, 
which  are  the  reflex  of  disorders  of  an  entirely  different  nature  is  con- 
cerned, electricity  is  often  of  a  great  deal  of  value,  and  when  it  is  of 
service  the  attention  of  the  physician  should  immediately  be  awakened 
to  the  possibility  of  an  underlying  organic  cause  for  the  hysteric  mani- 
festations. Thus,  the  common  association  of  hysteric  symptoms  with 
such  disorders  as  tumor-  of  the  spine,  tumor-  of  the  brain,  abcesses  ot 


522  MEDICAL    ELECTRICITY    AND    ROXTGEN    RAYS 

different  portions  of  the  body,  tumors  of  the  kidneys,  tuberculosis,  float- 
ing kidney,  stone  in  the  bladder,  etc.,  etc.,  all  of  which  conditions  are 
known  to  give  rise  to  hysteric  symptoms  very  frequently,  should  not  be 
overlooked,  and  when  these  are  alleviated  by  electric  treatment  the 
physician  should  not  be  deluded  into  belief  that  they  are  hysteric  and 
that  the  patient  is  well,  but  the  very  fact  of  their  being  amenable  to 
electric  treatment  should  point  in  the  direction  of  a  further  search  for 
the  cause  of  the  hysteric  manifestations.  Thus,  it  may  be  seen  that  the 
electric  treatment  of  these  conditions  offers  a  very  important  diagnostic 
clue. 

Mental  Disorders. — It  is  entirely  too  early  to  generalize  upon 
the  value  of  electric  forms  of  stimulation  in  mental  diseases.  If  it  be 
of  service  at  all.  it  is  of  some  assistance  in  the  treatment  of  depressed 
states,  usuallv  the  depressed  phases  of  maniacal  depressive  insanity. 
Also,  perhaps,  in  the  mild  or  severe  depressions  associated  with  senile  or 
presenile  psychoses  in  which  the  element  of  arteriosclerosis  is  the 
primary  pathologic  factor.  It  has  already  been  pointed  out  that  cer- 
tain forms  of  electric  energy  have  shown  themselves  to  be  of  service 
in  the  treatment  of  some  cerebral  tumors,  and  mental  changes  due  to 
cerebral  tumors  are  concomitantly  helped  thereby. 

It  is  beyond  question,  however,  that  electric  forms  of  energy  have 
no  radical  effect  on  any  definite  psychotic  conditions,  but  as  an  adjunct 
in  the  general  treatment  of  some  of  the  psychoses  electricity  is  unde- 
niably of  a  threat  deal  of  benefit.  And  in  the  large  groups  of  cases  of 
the  psychoneuroses,  particularly  in  the  neurasthenic  group  in  which 
the  mental  state  closely  approaches  insanity,  electric  stimulation, 
particularly  by  various  adaptations  of  the  static  current,  is  of  general 
tonic  value. 

The  exact  limitations  of  electric  stimulation  of  metabolism  and 
the  effects  that  such  change  in  metabolic  activity  may  have  upon  the 
development  of  psychoses  are  matters  which  are  as  yet  in  the  realm  of 
pure  hypothesis.  It  is  highly  desirable  that  careful  consecutive  studies 
be  made  on  definite  forms  of  psychoses,  so  far  as  we  believe  that  such 
definite  form-  do  exist,  in  order  that  clearer  notions  of  the  value  of  this 
form  of  energy  may  be  obtained. 

NEURASTHENIA 

The  beneficial  effects  of  electricity  in  tin.-  di-ea.-e  are  of  two  different 
physical  kind.-  besides  that  due  to  mental  impression.  Practically 
all  form-  of  electricity  which  are  suitable  for  use  in  this  disease  improve 
the  general  nutrition  and  digestion.  The  urine  contains  more  urea 
and  le.--  uric  acid  and  albumin  and  .-ugar  it  the  latter  are  present.  In 
ca  -<•-  oi  ma  1  nut  ni  ion  wit  h  phosplmt  una  and  a/ot  uria  elect  rich  v  increases 
bodily  weight  and  causes  the  urine  to  become  normal.  The  effect,  so 
far  d>  -'-ribi  d  i.-  one  of  regulation  ot  cellular  activitv  and  of  a  beneficial 
effect  upon  the  central  nervous  system. 

Th'-  -econd  kind  of  effect  from  elect  ncitv  is  upon  the  circulation, 
an  :  ':.  ".  \  be  in  the  direction  of  causing  an  elevation  or  a  reduction 
in  bl  oo'  i -pre. --U  re  according  to  1  lie  form  of  elect  ncity  which  is  emploved. 
<  ie>,,  .;::'_'.  extremely  high-tension  application-,  like  the  static 

spark  or  \>r*->  /.<•  and  the  .-park  or  eflluve  from  the  (  Midin  resonator  (the 
latter  ^ivmiz  a  hr_rh-frequency  high-tension  current ),  increase  the  blood- 


ELECTRICITY    IN    DISKASKS    OF    THK    NKHVOUS    SYSTEM  OZ.5 

pressure,  and  while  called  for  in  cases  with  hypotension,  are  contra- 
indicated  in  neurasthenia  with  high  arterial  tension  or  with  arterio- 
sclerosis. Comparatively  low-tension  high-frequency  currents,  like, 
those  from  the  d'Arsonval  apparatus,  have  a  marked  effect  in  lowering 
arterial  tension,  and  are  especially  indicated  in  neurasthenia  with  hiuli 
arterial  tension  or  with  arteriosclerosis. 

Application  of  Static  Electricity  in  Neurasthenia. — It  is  not 
necessarv  that  the  static  machine  should  be  of  the  largest  and  most 
powerful  type,  but  it  must  work  well  and  give-  a  good  discharge  between 
balls  '3  inches  or  more  apart. 

Static  Insulation  or  Static  Bath. — The  patient  sits  on  an  insulated 
platform  with  his  feet  resting  upon  a  metal  plate  connected  with  the 
negative  prime  conductor,  while  the  positive  prime  conductor  is  grounded. 
Treatments  last  for  five  minutes  at  first,  but  are  increased  to  fifteen 
minutes,  and  are  given  every  day.  This  is  an  excellent  tonic  to  all  the 
tissues  in  the  body. 

Static  Breeze. — The  patient  is  insulated  as  before  with  the  negative 
pole,  while  an  electrode  from  the  positive  terminal  with  one  or  several 
points  is  brought  near  some  part  of  the  surface  of  the  body.  The  effect 
is  a  sedative  one  upon  the  central  nervous  system.  For  instance,  the 
sensation  as  of  an  iron  band  around  the  head  is  relieved  by  a  few  minutes, 
application  of  the  static  breeze  to  the  nape  of  the  neck.  A  favorite 
application  in  neurasthenia  is  a  static  breeze  from  a  crown  suspended 
over  the  head  and  connected  with  the  positive  pole  while  the  patient 
is  negatively  insulated.  A  reversal  of  this  polarity  causes  a  much 
greater  prickling  sensation  in  the  scalp  and  makes  it  disagreeable. 

The  positive  pole  is  readily  distinguished  by  the  fact  that  the  dis- 
charge from  it  to  the  negative  pole  when  they  are  an  inch  apart  may  be 
diverted  by  a  piece  of  wood,  such  as  a  match.  Moving  a  piece  of  wood 
over  the  surface  of  the  positive  pole,  one  is  enabled  to  make  the  dis- 
charge start  from  wherever,  within  certain  limits,  the  wood  touches  or 
even  approaches  the  positive1  pole.  The  /;W//rr  discharge  follows  vond. 

Another  way  is  by  the  fact  that  a  brush  discharge  of  a  violet  light 
several  inches  long  may  be  obtained  from  a  pointed  electrode  connected 
with  the  positive  pole  of  the  static  machine,  while  no  discharge1  is  per- 
ceptible from  a  point  connected  with  the  negative  pole  until  it  is  close 
enough  to  send  a  spark  to  the  surface. 

Insomnia  from  neurasthenia  often  yields  to  a  static  bath  with  a  head 
breeze,  and  so  do  all  kinds  of  nervous  apprehension  and  even  delusions; 
but  excessive1  or  too  prolonged  stimulation  of  muscular  contraction  by 
the  static  wave  currents  will  cause  insomnia. 

Static  S/Hirkx. — The  patient  is  in  negative  insulation,  and  a  metal 
ball  electrode  connected  with  the  positive  pole  is  brought  near  enou.irh 
to  send  a  spark  to  the  surface1  of  the  body.  This  may  be'  applied  through 
the  clothes,  and  the1  ball  electrode  should  be  approached  with  a  sort  of 
quick,  striking  motion,  permitting  only  one  spark  to  pass  before1  the 
electrode  is  airain  beyond  sparking  distance.  A  stream  of  sparks  at 
one'  place  is  painful  and  exceedingly  disagreeable. 

For  a  general  tonic  effect  and  to  raise  the  arterial  tension  a  series 
of  sparks  along  the  spine  are1  excellent. 

They  cause  localized  contraction  of  muscular  fibers  and  are  indicated 
in  pronounced  muscular  atemy,  either  ^enei'al  or  local. 


Static  sparks  applied  in  the  left  iliac  region  have  a  most  beneficial 
effect  upon  the'  constipation  which  is  often  a  symptom  of  neurasthenia, 
and  they  al-o  iv-toiv  the1  appetite  and  relieve  the1  general  seMise1  e>f 
depression. 

I  no1  i  net  Static  N/v;/7,'N.-  -For  all  the1  purposes  for  which  static  sparks 
are  applied,  the  effect  may  be  obtained  by  grounding  the  positive1  pole  of 
the  static  machine  (connecting  it  with  the  water  or  gas  or  steam  pipes), 
and  applvim:'  the  -parks  from  an  elect  vode  which  is  also  grounded.  This 
make-  the  application  much  easier  for  the  operator,  since  the1  electrode 
i-  not  charged  and  need  not  be  insulated. 

St'itir  b"rii-tion  or  Mn.wujc. — The  patient  is  in  negative  insulation, 
and  the  positive1  pole  is  connected  with  a  roller  electrode,  which  is  rubbed 
over  the  surface  of  the  body  outside  the  clothes,  or  the  same  applica- 
catioii  may  be  made  indirectly,  grounding  the  positive  pole  and  the 
roller  electrode.  The  effect  is  that  of  a  continuous  shower  of  sparks, 
the  length  of  which  is  determined  by  the  thickin--  of  the  clothing.  The 
application  is  a  severe  one  and  makes  the  strongest  man  twist  and 
-quirm.  The  electrode  should  be  moved  over  the  surface  quickly  and 
;  not  be  applied  for  more  than  a  few  seconds  at  a  time.  Pron1 
ha-  most  admirably  epitomized  the1  indications  for  static,  faradic.  and 
galvanic  applications  in  this  disease1.  He  considers  static  massage  as 
ii-eful  in  cases  with  anesthesia  en  plaques  and  with  spinal  cord  irri- 
ti.  causing  seminal  emissions  and  cramps  and  exaggerated  rellexes. 
The  applications  are  made  to  t  he  upper  part  of  t  he  body. 

77'"    >'/r//,V-,'  nil  /in  il   (  7//-/V///.  —  The   pelvic  neuralgia    of   neurasthenia 
in  women  i-  almost  al\va\>  relieved  by  vaginal  applications  of  the  st at  ic- 
ed current.      Albert -\VeillV  met  hod  of  application  is  by  a  vaginal 
electrode  connected  with  his  rheostat  for  controlling  the  strength  of  the 
-' at  ic-induced    current.      The   operator    holds    the    insulated    handle    of 
this  electr,,de  with  one  hand  while  he  massages  the  abdomen  with  the1 
it  In  r. 

The  application  should  be  as  strong  as  can  be  borne  without  discom- 
fi  Hi. 

The  symptoms  especially  calling  for  treatment  by  static  electricity 

and  mvasthenia. 

Faradic  Applications.     These  are  not  made  with  a  view  to  causing 
ilar  contractions,  and  the  current    must,  therefore,  be  a  weak  one 
and    preferably    one   with    the   most    rapid    possible    interruptions.      The 
.  i"er  an    •  a-ily  si  cured  if  the  faradic  coil  is  made  with  a  ribbon  inter- 
:  ipter.       \     trip  of  steel  tape  is  the  vibrator  which  interrupts  the  pri- 
mary   CU;TI  nt.      It    i-   permanently    fastened    at    one   end    and    mav    be1 
turning  a   screw  at    the  other  end.      The  tenser  the  steel 
••  '     i  are  the  vibrations  produced  by  the  action  of  the 
'    which  i-  placet)  oppo-ite  the  middle  of  the  ribbon.       The 
",<'!'  lie    -uccession    of    induced    current.-,    the    less    is   the   effect 

.'i  '•;•.'.  •     .       .  ;tr  contraction  and  the  greater  i-  the  tonic  effect  upon 

vstem.      The  faradic  coil  slienild  have  an  adjustable 
(he  secondarv  coil  and  the  greatest   number  should 


ELECTRICITY    IX    DISKASKS    OF    THK    XKKVol'.s    SYSTKM 

ceptible  polarity,   t>ut    this  is  so   very  slight    that    cither  electrode 
be  used  indifferent  ly. 

(rencral  faradization  is  useful  in  eases  of  neurasthenia.  The  patient 
sits  upon  or  lets  his  feet  rest  upon  a  large  sheet  of  metal  covered  with 
wet  flannel  as  the  indifferent  electrode.  The  other  electrode  is  passed 
over  the  forehead,  the  nape  of  the  neck,  the  spine,  the  precordia,  and 
the  abdomen.  This  active  electrode  may  consist  of  a  damp  sponge 
electrode  or  it  may  be  the  operator's  hand.  In  the  latter  case  the 
operator  holds  a  metallic  or  sponge  electrode  connected  wuh  the  active 
pole  and  the  current  passes  through  his  body  to  the  patient.  The 
treatments  last  about  ten  minutes. 

Heard  considered  general  faradization  as  especially  indicated  in 
neurasthenia  with  myasthenia  and  malnutrition,  and  that  it  should  be 
avoided  in  very  excitable  neurasthenics,  for  whom  static  electricity 
seems  to  be  better. 

Loral  Faradization. — Krb's  treatment  for  cerebral  or  spinal  neuras- 
thenia is  by  local  applications  alone  of  faradization  for  only  two  to  five 
minutes. 

Bladder  symptoms  of  a  paralytic  type  in  men  may  be  treated  by 
faradization  with  the  indifferent  electrode  on  the  abdomen  or  buttocks, 
and  the  active  electrode  applied  to  the  perineum  and  scrotum  succes- 
sively. Rapid  interruptions  and  a  fine  secondary  coil  are  used. 

The  pelvic  neuralgia  or  neurasthenia  in  women  is  best  treated  by 
static  electricity  applied  intravaginally,  as  has  been  described  on  page 
")24,  or  by  vaginal  faradization.  For  the  latter,  sponge  electrodes  are 
held  in  the  vagina  and  over  the  abdomen.  Very  rapid  interruptions 
and  the  maximal  strength  of  current  are  used  for  ten  minutes  each 
day. 

Galvanic  Applications. — (Icncral  galvanization  is  applied  from 
a  large  indifferent  negative  electrode  applied  to  the  feet  and  an  active 
positive  electrode  rubbed  over  different  parts  of  the  surface.  Two  to 
four  milliamperes  is  the  proper  strength  of  current.  Such  an  applica- 
tion is  not  very  often  employed. 

( '<  ntral  t/ah'aniz<tl'ion  may  be  used  when  the  pat  ient  is  well  nourished, 
and  his  muscular  strength  has  not  been  affected  by  the  disease.  A 
large  negative  electrode  is  placed  over  the  epigastrium,  and  a  small 
active  positive  electrode  is  applied  successively  to  the  forehead  and 
vertex  for  one  or  two  minutes,  and  then  to  the  sides  of  the  neck  and 
down  the  spine  for  two  To  five  minute's.  A  current  of  ">  to  10  ma.  is  used, 
but  it  must  be  gradually  turned  on  for  each  position  of  the  active  elec- 
trode, and  graduallv  turned  off  before  the  electrode  is  removed  from 
each  place.  The  strength  of  current  may  be  a  little  greater  at  a  distance 
from  t  he  head. 

Lni'nl  (lulvnnizution. — The  uniform  and  uninterrupted  galvanic  or 
constant  current  is  used  for  two  or  three  local  conditions. 

Abdominal  neurasthenia  is  successfully  treated  by  a  laruv  kaolin  pad 
under  the  back  and  one  the  si/e  of  an  outspread  hand  over  the  epigas- 
trium. 100  to  1")0  ma.  sinusoidal,  2S  to  the  minute. 

Impotence  from  neurasthenia  in  men  may  be  treated  by  a  cm-rent 
of  10  to  20  milliamperes,  flowing  for  fifteen  minutes  between  a  larue 
indifferent  positive  electrode  at  the  genital  center  in  the  spine,  and  an 
active  negative  electrode  passed  over  the  perineum,  scrotum,  spermatic 


f)2<>  MKDICAL    ELKCTKU'ITY    AND    KONTCEN    KAYS 

cord,  and  the  root  of  the  peni<.  Albert  -Weil  sometimes  terminated 
each  treatment  by  rhythmic  galvani/ation.  Treatments  are  given  daily. 
Impotence  is  a  condition  in  which  the  discovery  and  removal  of  the 
cause  of  the  trouble  is  extremely  important.  Such  a  condition  as 
hemorrhoids  or  rectal  ulcer  may  interfere  with  the  -access  of  any  treat- 
ment directed  toward  the  genital  organs  alone,  and  then  again  every 
one  reali/es  the  profound  influence  of  the  mind  over  this  condition. 

Cnnxti'iMitiun.-  This  i-  almost  always  a  condition  of  spasmodic  con- 
traction in  neurasthenia  and  is  relieved  by  the  constant  current  of 
rather  high  amperage  (l/i  or  20  milliamperes  through  large  electrodes) 
over  the  abdomen.  Oilier  means  are  tlie  static  spark  to  the  left  iliac 
fosO[.  rhythmicallv  varied  and  reversed  currents,  and  galvanofaradi/a- 
t  ion. 

('<  /ilnili/'  ( ;<i!  run  i:iili<ni . — This  is  suggested  bv  Leduc  for  cases  of 
n-tvbral  neurasthenia.  A  large  positive  electrode  is  placed  at  the 
nape  of  the  neck  and  a  negative  electrode  .")  by  10  cm.  in  si/e  is  placed 
on  the  forehead.  The  current  must  be  turned  on  very  gradually  until 
L'n  ina.  an-  applied.  This  is  continued  for  a  i|uarter  of  an  hour.  There 
is  an  immediate  sense  of  relief,  clearness  of  thought,  and  ability  to  work. 
The  wromr  polaritv — /.  P.,  with  the  positive  pole  upon  the  forehead  — 
produces  a  disagreeable  sensation  of  heaviness,  slowness  of  thought, 
am  1  somnolence. 

I'm  ii /not/it.^/nr  f/filrnnizfition  mav  be  employed  for  the  relief  of 
cardiac  palpitation  and  erethism.  The  positive  electrode  i.;  placed  in 
the  mas.toid  fossa  and  the  negative  over  the  upper  border  of  the  clavicle 
an  inch  and  a  half  from  the  .sternum;  a  current  of  from  ">  to  10  milliam- 
peres  is  turned  on  gradually  and  allowed  to  How  for  five  or  ten  minutes. 
It  is  turned  off  just  as  gradually. 

I  I-TIJ  IIc'ii'i/ (idl rnitic  ( '"/'/v  tttx  fo/' ('oiixtipntion  in  \  cnTuxthcn m . — '1  his 
method.  Used  by  Hartenberg,1  has  not  yet  been  generallv  tried.  The 
patient  is  seated  upon  one  electrode,  and  another  as  large  as  possible 
i-  applied  over  the  abdomen.  The  current  is  of  [o  volts  and  200  ma. 
and  i-  applied  every  thirty  seconds  for  an  instant,  first  in  one  direction 
and  then  in  the  other.  Vigorous  contractions  of  tin1  abdominal  and 
intestinal  walls  lake  place.  There  i<  no  irritation  of  the  skin.  Forty 
such  double  shocks  ^closure  and  opening)  are  applied  at  first  every  (lav. 

( till  1'Hinr  ( 'u/'t'i  iifx  Inr  1 1 1  iiilii<-h<  in  \  (/Tons  I  )//.--•  [it  />*/n.-  A  current 
of  x  t.i  I'l  ina.  i-  applied  witli  one  electrode  at  the  nucha  and  the  other 
on  the  forehead. 

High-frequency   currents  lm\e  become  a   mosl    important    factor 
•;:.•:.'  oj  neurasthenia.      The  general  indicat  ions  as  to  tension 
been   alluded   to.      'I  he  d'Arsonval,   or  low-tension   hiidi- 
•  •  '    .   are  -mied  to  cases  with  hi'_di  arterial   tension,  and 
lh<    '  >udiii    and   oilier  hi^h-tension   hinh-fre(|uenc\-   currents  are.  suited, 
•  1        v    a rt erial  tension. 

'  mi.     for    fliijli-l'i't '/in  nrif   ( 'urn  nfx    in    \(  iiffixthcniti.— 
/'          -;•  nn    bv    high-tension    hnrli-H'ci  juency    currents    i.-    more 
•       than  any  other  method  except    m  cases  with   high 
\    bipolar  <iiidin    resonator  or  a    pair  of  ( iiiillemiiiot 
i      ,    •    i    and    a    metal    plate   connected    \\ith   one   pole   is  applieii 
'   \    to  I  i  ;   I  he  neck,  while  t  l,e  oi  h<  r  i  :o|e  i-  connect  ed  wit  h 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  527 

an  effluve  electrode  held  near  the  surface  of  the  epigastrium;  or  this 
e.ect  rode  may  be  a  vacuum  bulb  rubbed  over  the  surface  of  the  abdomen. 
In  either  case  the  benefit  is  due  to  two  factors — first,  the  surgings  of 
high-frequency  and  high-tension  currents  through  the  patient;  second, 
the  ultraviolet  rays  produced  by  the  eflluve  from  the  brush  electrode, 
or  by  the  shower  of  tiny  sparks  from  the  vacuum  electrode.  This  liber- 
ates ozone  from  the  atmosphere,  which  is  carried  into  the  system  through 
the  skin  to  produce  a  tonic  effect.  This  application  should  last  a  quarter 
of  an  hour,  and  Albert-Weil  finishes  the  seance  by  placing  the  fixed 
metal  plate  electrode  over  the  epigastrium  and  passing  the  brush  elec- 
trode up  and  down  the  spine  for  ten  minutes.  In  high-frequency  treat- 
ment the  metal  electrode  applied  directly  to  the  surface  of  the  body  may 
be  considered  the  indifferent  electrode.  The  brush  electrode  by  which 
an  efrluve  is  applied,  or  the  glass  vacuum  electrode  with  its  shower  of 
tiny  sparks,  either  electrode  making  a  direct  application  of  ultraviolet 
radiations  and  of  ozone,  may  be  considered  the  active  electrode.  The 
nerve  centers  requiring  especial  tonic  treatment  in  most  cases  of  neuras- 
thenia are  the  solar  plexus  and  the  spinal  cord. 

Loir  arterial  tension  is  progressively  improved  by  bipolar  applications 
of  high-tension  high-frequency  currents  applied  through  a  metal  elec- 
trode at  the  epigastrium,  and  a  succession  of  sparks  of  considerable  size 
applied  along  the  spine.  A  metallic  electrode  may  be  used  for  the 
latter  purpose,  but  a  glass  vacuum  electrode  is  much  more  convenient. 
A  greater  strength  of  current  and  a  less  close  application  of  the  vacuum 
electrode  as  it  is  passed  over  the  surface  makes  the  difference  between 
sparks  of  considerable  size  and  tiny  or  imperceptible  ones.  Moutier 
secures  the  same  increase  in  arterial  tension  by  sparks  from  a  monopolar 
resonator,  and  the  present  author  usually  employs  this  method,  which 
has  the  great  convenience  that  it  can  be  applied  through  the  clothing. 
Albert-Weil  thinks  that  the  bipolar  application  is  a  little  more  effective. 

Dyspepsia. — The  pain  is  often  relieved  and  the  action  of  the  stomach 
and  intestines  regulated  by  a  bipolar  high-tension  high-frequency 
current  from  a  metal  electrode  in  contact  with  the  back  and  an  efrluve 
or  a  vacuum  electrode  applied  over  the  stomach. 

I»i/>otcnrc. — One  high-frequency  application  suited  to  this  symptom 
in  male  neurasthenics  is  from  a  bipolar  resonator,  with  an  efnuve  over 
the  epigastrium  and  a  spark  electrode  applied  over  the  genital  center  in 
the  spinal  cord. 

The  author  has  had  successful  results  with  a  monopolar  application 
from  the  Oudin  resonator  and  a  glass  vacuum  electrode  to  the  penis, 
scrotum,  and  groins.  A  strong  application  is  employed,  regulated  so 
as  to  produce  a  current  which  makes  the  glass  quite  hot.  but  with  very 
little  spark  effect,  powder  being  used  to  enable  the  electrode  to  slip 
smoothly  over  the  surface  without  breaking  the  contact  or  producing 
perceptible  sparks.  \o  effect  may  be  noted  at  the  first  treatment,  but 
during  the  subsequent  treatments  the  erections  become  extremely 
vigorous.  Functional  power  is  restored,  but  whether  there  is  a  relapse 
depends  upon  the  patient's  general  condition. 

A  further  consideration  of  the  u.-e  of  high-frequency  current.-  in  this 
disease  is  found  on  page  587. 


MMDH  AI.     KI.K<  TKK   ITY    AND    KoVl  < .  I  IN     KAYS 


ELECTRIC  SLEEP  AND  ELECTRIC  DEATH 

Electric  Sleep.     Tin-  i-  ;i  name  ^iven  in  ;i  t'nmi  <>t  anesthesia  which 
Si  rphane   I.ediic  has  been  able  to  brim:  abniit    in  annuals  ami  in  man 
as  a  !'•-•;:'  <  >!  i  he  application  ni'  a  type  nf  elect  ric  current  which  In1  himself 
has  devi-ed.      The  current   ha.-  already  been  spoken  of  in  the  paragraph 
nil  local  anesthesia  ami  the  t  ivat  ment  0$  neural irias.    1 1  i.-  an  intermit  tout 
current    ni'  low   tension   and   nf   infrequent    interruption,    which   passes 
re    !>i xly    nf    the    animal.      The    interruptions    in    the 
nt.  as  has  alreadv  been  stated,  run  from  !M)  to  1  HI  per  second,  and 
the  electromotive  fnive  rarrly  exceeds  '.->()  volts.     The  strength  of  cur- 
rent i-  4  ma.      The  apparatus  is  described  on  paize  4'.H. 

l.educ  \vas  alile.   in    p.tO'J  Oil,   to  briim'  aliout    complet<'  narcosis  in 
ils  by  the  application  of  his  current  directly  in  the  cranium,  one 
electrode    bejuM-   placed    upon    the    head    and    the   other   either   upon    the 
extremities  nr  over  tin'  abdomen  ol  the  annual. 

The  de-criptimi  nf  whal  take-  place  can  perhaps  be  best  told  in  his 
own  wnrds.  fni1  he  made  liimself  the  subject,  nf  an  experiment  and  his 
assistants  placed  him  under  ireneral  electric  anesthesia. 

The  results  nf  his  experiments  were  communicated  to  the  French 
>•  icii  •  •'•  de  Binlnu'ie.  XnN'ember  '2'2.  I'.iirj.  and  in  the  Archives  d'Klectricite 
::.  '  lii-ale.  July  1").  l!M):>.h<.'  ii'ives  us  a  description  nt  Ins  own  sensations 
when  passing  into  the  electric  anesthesia. 

( >ne  laru'e  electrode  fnrmed  of  absorbent    cotton  impregnated  with 

1:  HID  solution   nf  chlorid  of  sodium,   witli  a   metallic   plat*'  behind,   is 

placed  on  the  forehead  and  fastened  to  the  head.      Tin-  frontal  electrode 

i-  the  cathode.      A  larger  electrode  made  m  the  same  manner  is  placed 

over  the  hack   and   fastened   there  by  mean-  of  an   elastic   band.      The 

•  current    is  then  turned  on.  beim:'  interrupted  for  the  first  tenth 

period   of  application   one  hundred   times  to   the  second.      The 

-•  n-ai  ion  produced  by  i  he  stimulation  of  i  he  superficial  nerves,  although 

-liiih'l;    disagreeable,  can  be  easily  endured. 

After  ;;   -hurt    tiin<'  the  patient    feels  a  calm  -imilar  to  the  sensation 
;i    continuous    curi'i'iit.    and    tin-,    after   having    passe<l    its 
.     diminishes,     not  \vitlistandin.ii     a     gradual     increase 
•    •    ec!  i-i  imol  i\'e  fi  iri-e  i  if  t  he  current  . 

I  '      :    ci    ;  —  inn  -  fed.  -lii:ht  contractions  of  the  muscles  of  the  face. 

;    even    of   the    forearm    occur,    and    fibrillary    tremor-   of   the 

.'  •  -   '::.••   place,   then   one  feels  a   im^htiL;'  nf  the  extremities  in 

;   in  the  hands,  \\-hich  uraduallv  extends  to  tin-  to<'s  and 


p!'e~~    hi-   thoiiLih'-.   altlioiiLi'li    he   has   active   cerebration 

'  '  e  '  inie.        Then   1  he  motor  cent ej-s  a  1'e  colllpletelv   inhibited, 

•'-I'    read    ev<'ii   i  o  t  IK-  niosl    :  •     tlat  ions,   he  is 

ate  with   the  experimenters  alt  hoil'-dl   full  V  co  n -ci  OUS. 

,'it houl    In    •  complete  state  of   rela.xat  ion, 

tirular  invoK'ement-;  certain  choking  or  tremors, 

to    aiiv    pallil  —  ion-,    may     t  ake    place,    but 

1    -  \cit  at  ion   in   t  he  mu-c]e~  nf  1  lie  lai'VUX. 

I  •        •      '  '  •     appearanci      remains    abso    itely    unaltei'ei  1.     t  he 

.  •   •     .  |  •    ,.,  ; 

•—,.,  .  feeling  as  thnii'jh 


KLKeTKHITY     IN"     DISKASKS    OK    TI I K    NKKVOO    SV.-TKM 

he  were  in  a  dream,  and  although  hearing  things  al)ou1  him.  he  only 
half  appreciated  what  was  going  on.  He  had  a  feeling  of  conseiousnes> 
of  hi>  own  impotence  and  iiuihility  to  communicate  with  his  colleagues. 
The  contacts,  the  pinching  and  the  pricking  in  the  forearm,  could  lie 
felt,  hut  the  sensations  were  much  diminished,  as  in  .a  very  large  swollen 
member. 

The  most  painful  impression  was  to  notice  the  dissociation  and  the 
successive  disappearance1  of  the  faculties;  the  impression  was  identical 
with  that  which  one  feels  in  a  nightmare  in  which,  in  the  presence  of  a 
great  danger,  one  feels  that  one  is  neither  able  to  cry  out  nor  1o  make 
any  movement . 

In  his  first  experiment  consciousness  was  not  entirely  abolished, 
but  in  a  second  seance  his  colleagues  advanced  to  the  point  where,  so 
tar  as  they  were  able  to  determine,  consciousness  had  lapsed  completely, 
but  heduc  was  able  to  feel  that  this  had  not  really  taken  place  because 
there  was  not  complete  suppression  of  all  sensihilitv. 

The  electromotive  force  had  been  raised  as  high  as  oo  volts,  the 
intensity  in  the  interrupted  circuit  being  1  milliamperes.  In  each  one 
of  the  seances  he  remained  twenty  minutes  under  the  influence  of  the 
current. 

Awakening  was  instantaneous  and  the  after-effect  was  a  mild  state 
of  exhilaration. 

With  animals,  however,  as  has  been  shown  by  Leduc  and  his  pupils 
and  by  many  other  observers,  the  electric  sleep  may  be  prolonged  for 
considerable  periods  of  time — for  three  or  four  hours  at  least — and 
operations  may  be  performed  upon  them. 

Certain  points  have  been  brought  out  with  reference  to  this  electric 
sleep  which,  although  as  yet  not  definite,  may  be  outlined  at  this  time. 
In  order  to  produce  the  electric  sleep  according  to  the  experiences 
which  have  thus  far  been  reported,  it  would  appear  that  the  ordinary 
street  current  is  not  as  valuable — or  as  safe,  it  would  perhaps  be  better 
to  sav — as  a  current  which  is  delivered  more  equably,  as  from  a  storage- 
battery.  The  street  current  which  charges  a  storage-battery  and  i.- 
utilized  from  tin-re  would  be  the  ideal  current.  The  arrangement  sug- 
gested bv  a  number  of  experimenters  would  be  to  utilize  the  storage 
current  for  the  electricity  which  is  to  traverse  the  body,  and  the  street 
current  to  run  the  motor  of  the  interrupter. 

(Iradiial  application  of  the  current  is  to  be  preferred  to  an  abrupt 
( losage. 

The  negative  pole,  the  cathode,  should  always  be  applied  to  the 
head,  for  experience  lias  shown  that  if  the  anode  be  applied  to  the 
head  grave  disturbances  in  respiration  take  place  and  the  temperature 
is  apt  to  go  up. 

( 'ert  a  in  coi  i  di  I  ions  are  observed  to  be  nmre  or  less  constantly  present . 
Thus  the  pupils  are  usuallv  contracted  durum'  the  stale  ot  electric  sleep. 
The  temperature  is  usual!}'  about  normal  or  slightly  above.  lli'1  res- 
piratory rhyt  hm  is  slight  1  v  hastened.  There  is  usually  an  increase  in  tin1 
arterial  |  iressure  which  seems  to  depend  upon  v  a  so  mot  or  cause-.  (  VIM  am 
of  the  reflexes  seem  to  be  exaggerated,  while  others  are  diminished. 

In  overdosage,  leading  to  an  electric  epileptic  state  or  to  electrocu- 
tion by  the  Leduc  current,  the  blood-ressure  Mif'fer.-  a  ver  marked 


O.M)  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

Whether  the  Leduc  current  can  be  used  to  advantage  in  electro- 
cution of  the  human  being  is  for  the  future  to  decide,  but  there  arc 
certain  facts  which  point  to  its  desirability  in  this  direction. 

As  to  it<  applicability  in  man  for  anesthetic  purposes,  the  future 
alone  will  be  able  to  determine.  At  the  present  time  of  writing  the 
fact<  brought  out  by  the  application  of  this  new  type  of  current  are  of 
extreme  theoretic  importance,  but  it  has  not  been  tried  in  a  sufficient 
number  of  cases  to  justify  any  general  statements  concerning  its  applic- 
ability for  general  narcotic  purposes. 

Local  Anesthesia  from  Electric  Currents. — This  has  been  obtained 
by  II.  (  liin/el.1  u-ing  a  direct  2~)  to  oO  volt  current  of  2  to  10  ma.  inter- 
rupted 2oO  times  a  second.  The  anode  is  placed  on  the  skin  over  the 
painful  spot  and  the  cathode  at  some  indifferent  place.  He  has  found 
it  effective  in  migraine,  bronchial  asthma  (with  the  anode  on  the  neck), 
and  aniiina  pectoris. 

Electric  Death  (sec  also  page  3li~i. — Internal  lesions  in  death  due  to 
industrial  electricity — pathognomonic  lesions  for  the  most  part  have 
been  absent  in  these  cases.  Numerous  experiments  have  been  made  on 
animals  to  determine  the  causes  of  death  and  the  character  of  the  lesions. 
The  earliest  experimental  investigations  made  on  animals  with  the 
modern  industrial  electric  currents  that  are  of  service  in  the  present  pres- 
entation were  those  of  (Irange,  (lariel,  and  Brouardel,  made1  in  1884, 
and  those  of  B.rown-Sequard  and  d'Arsonval2  in  1S8(>  and  1887.  It 
r-hould  be  borne  in  mind,  however,  that  Priestlv,  as  early  as  17(ib',  killed 
animals  by  static  electricity,  and  that  at  that  time  numerous  experi- 
menters followed  him,  notably  Fontana.  the  Italian  physicist.  The 
experiments  of  Xothnagel  in  l^M)  are  also  worthy  of  record  in  this 
relat  ionship. 

D  Arsonval's  results  will  be  referred  to  under  the  paragraph  on 
Causes  of  Death,  since  he  was  interested  in  the  physiologic  side  of  the 
problem  only.  From  the  pathologic  point  of  view  the  investigations 
of  Peterson  and  Doremus,  conducted  in  the  Kdison  laborities  in  ISSS, 
are  of  interest. 

Animal  experiments  made  by  Krattera  within  recent  years  on  mice, 
sruinea-pigs,  rabbits,  cats,  and  dogs  show  certain  signs  regarded  by  him 
::-  more  or  less  pathognomonic  of  the  condition.  Subpericardial  and 
subpleural  ecchymoses  and.  more  particularly,  subendocardial  ccchy- 
motic  extravasations  occurred  in  mo.-t  of  his  cases,  combined  with 
bloody  emphysema  o|  the  larger  bronchial  ramification-.  These  signs, 
:  •  u  '•:  :  :.  iii  conjunction  with  the  external  burn.-,  are  believed  by  him 
'•lent  to  make  the  diagnosis  "death  by  electricity."  Riu'or 
-  \  •  ry  rapidl  v  and  persisted  for  a  di-t  inct  period  of  t  ime. 
in  ih"  brain  and  spinal  cord  were  not  prevalent, 
•  \vere  subdural  and  mternieningeal  hemorrhagic 
se  are  of  interest 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  531 

other  recent  writers  would  seem  to  prove  quite  conclusively  that  such 
do  not  occur  save  at  the  sites  of  electrode  contact.  Cunningham1 
has  shown  that  if  the  thorax  he  opened  immediately  following  death 
due  to  strong  continuous  currents,  the  heart  on  close  examination  will 
be  found  to  show  a  minute  quivering  throughout  its  entire  muscular 
substance.  While  the  coordinate  beats  of  the  ventricles,  as  a  rule,  are 
absent,  the  numerous  isolated  bundles  of  muscle-fibers  will  be  found 
alternately  to  contract  and  relax  with  vigor  in  different  parts  of  the 
ventricle;  and  as  the  right  and  left  auricles  become  gradually  distended 
this  irregular  quivering  of  the  muscle  bundles  grows  feebler  and  feebler, 
until  every  trace  of  muscular  contraction  has  disappeared.  This  state 
of  delirium  cord  is  or,  as  Cunningham  prefers  to  call  it,  "fibrillary  con- 
traction," as  the  cause  of  death  was  first  pointed  out  by  Cunningham, 
and  also  independently  by  Pn'vost  and  Battelli.  2 

The  nervous  tissues  have  been  carefully  searched  for  pathologic 
changes,  and  it  has  only  been  within  recent  times  that  distinct  changes 
have  been  found.  It  seems  not  improbable  that  changes  of  importance 
would  be  found  by  the  newer  technical  met  hods  of  investigation,  but  thus 
far  only  a  few  workers  have  employed  the  Xissl  methods,  or  modifications 
of  the  same.  Kratter's  observations  were  made  by  the  older  methods, 
and  he  found  no  special  cell  changes.  He  confirms  the  observations 
made  by  Peterson,  Spitzka,  Van  (lieson,  and  others  that  minute  capil- 
lary hemorrhages  in  the  perivascular  spaces  are  present,  especially  in 
the  superficial  layers  of  the  cortex,  but  these  he  distinctly  shows  are 
not  universal,  and  cannot  be  regarded  as  of  sufficient  moment  on  which 
to  base  a  pathologic  diagnosis  of  death.  He  concludes,  however, 
that  he  believes  that  minute  changes,  not  known  to  our  present  technical 
methods,  arc  responsible  for  death  by  electric  currents.  More  recently 
Corrado  8  has  shown  that  such  minute  changes  may  be  demonstrated 
by  means  of  the  more  modern  histochemic  methods. 

Con-ado's  conclusions  may  be  summarized  as  follows: 

The  continuous  electric  current  derived  directly  from  the  commu- 
tator and  applied  to  robust  adult  dogs  weighing  from  2.5  to  20  kilos 
(5  to  50  pounds),  one  electrode  being  placed  on  the  head  and  the  other 
on  the  lower  portion  of  the  spinal  cord,  with  a  voltage  of  from  720  to 
2175  volts,  and  an  amperage  of  20  to  30,  or  in  two  dogs.  10  to  12  amperes. 
produced  death  in  every  instance.  Death  occurred  immediately  and 
was  not  influenced  by  artificial  respiration,.  On  the  closure  of  the  cir- 
cuit the  animal,  without  emitting  a  cry,  became  rigid,  and  all  the  mus- 
cles, especially  those  of  the  back,  contracted  violently,  producing  a 
pronounced  opisthotonos.  This  rigidity  persisted  for  from  one-half 
to  one  minute  after  the  cessation  of  the  flow  of  the  current.  Kespira- 
tion  was  arrested  from  the  first  moment  of  the  passage  of  the  current. 

An  examination  of  the  ganglion  cells  of  the  brain  and  spinal  cord 
by  the  newer  methods  of  Xissl  and  also  by  the  method  of  (iolgi  showed 
a  number  of  interesting  lesions,  the  importance  and  interpretation  of 
which  are  only  just  beginning  to  be  appreciated. 

Corrado  describes  changes  as  occurring  in   the  external  shape  and 

'  New  York  Medical  .T<>urn;il.  Oct.  IX  lvi«).  pp.  oSl,  tilt'.. 
J  Comptes  rcndu-  dc  1' Academic  dcs  sciences.  March  lo.  27.  ls(,H>. 
3  G.  Cnrrado,  I  >c  alcunc  altcra/ionc  dellc  cellule  ncrvosc  nella  morte  per  cllct- 
trinta.      Atti.  d.  K.  A^sad.  nicd.  ( 'hir.  di  Napoli.  1MN  vol.  Ixxv. 


\i.   i:u:<  run  ITY   AND   UII.NTCKN    KAY 


ly.    chanties  of   the   cytoplasm   and   of   the 

A.  Changes  in  the  Cell  Contour.  (1)  Noteworthy  and  various 
deformit  ie-.  erosions,  jan^ed  outline.-,  laceration-,  and  e\'en  severe 
destruction  of  the  cell  outline.  rJ)  The  contour  of  the  cell  became 
ha.'v  and  diffuse.  (.'!)  In  some  cases  the  protoplasm  became  granular 
on  one  -i<[< •. 

H.  Internal  Cell  Changes,  ih  A  jirade  r  t  dissolution  of  the  chro- 
matic substances  with  powdery  granulations  was  observed.  The  cell 
contents  were  more  homogeneous  and  showed  the  beginning  changes 
of  chromatolvsis.  cJ)  l-retnient  and  pronounced  vacuolation  (perhaps 
artefact).  101  The  chromatic  substances  had  a  .-light  tendency  to 

1 mie  dispersed  in  the  remainder  of  the  cell-body,  at  times  in  distinct, 

•lions,  \\lndi  in  certain  parts  ot  the  cerebral  cortex  had  a  special 


arrangement.      Then-   collections   of  chromatic    particle-   were   not    dis- 

[>  •      ;   in   the  ilireciiuii  of  th"  pas.-a^e  of  the  electric  current.      (I)   The 

'i"'"    I'-i-taiit.       It     may.     however,     be     modified     iii    shape, 

in    si/.f,   or   may   i-ntirely   di.-appear.      The   contour 

'.  be  irn  ^ular  ore  \-en  angular.    The  chromatic  sul>st  a  nc« 

''    'h'1  :    •"'    '     nia\    In-  irreu'u'arly  di-posed.   granular,  arranu'cd  in   line 

a  I  1  he  periphery,  or  ii  may  i  Ml  irely  disappear,  lea \-iim' 

Tin-  po.-ii  ion  of  i  he  nuclcii.-  mav  vary.      A  cer- 

1    '    lor  il   lo  be  located  on  <  me  ,-i(|e,  especially  to 

'he   accumulation   ,,\    chromatic   subslaiiees  occur.-. 

may    be    bmken.        ,"i      Die    nudeohis    i.-    the 

"f  'he  cdi.      I'     -  tor  the  im.-i    ji;,n    preserved  and 

'•i    the  remain'  i'  r  of  t  he  n  ||  i .  profoundly-  altered. 

'     '    'H    -i/e.        li    has   a    lendi  ln-\     to   an   eccen- 

•  •  'i  '"it   to  the  periphi  n    of  i  he  nucleus  or  even 

loth. 


F.l.Ki  TinciTV    IN    DIs-F.AsKs    OF    TIIK    XKKVOT 


,Y>TKM 


Cornulo  ;ilso  describes  a  sci'ics  of  changes  it)  specimens  treated  by 
11  ic  (  lolgi  met  hods.  These1  cl  unices  of  t  he  dendrites  eonsisl  for  t  he  most 
part  of  varicose  atrophy,  fragmentation,  and  other  modifications  of 
>ha|>e  and  position.  Since  the  (lolgi  method  and  its  no\v  known  modi- 
tications  show  precisely  such  ch;i  Hires  in  normal  material,  it  is  fairly  well 
established,  by  reason  of  this  and  also  on  account  of  the  great  lack  of 
uniformity  in  the  (lolgi  ])ictures,  tliat  it  is  unwise  to  describe  these  as 
degenerative  lesion-  pathognomonic  of  any  diseased  condition.  Hence, 
these  observations  of  CoiTildo  by  means  of  the  (lolgi  method  are  not 
considered  final. 

In  man  the  pathologic  features  have  been  closely  followed,  though 
not  as  yet  by  the  newer  methods.  Electrocution  has  given  the  most 
accurately  observed  cases,  and  the  investigations  of  Spit/ka,  Van  (lieson, 
and  Kratter  are  the  most  elaborate1.  In  the  case  of  William  Kemmler,  the 
first  officially  electrocuted  criminal  under  the  modified  statutes  of  the 
State  of  Xew  York,  the  following  autopsy  record  is  taken  from  the  notes 


3    ,  \fe     J       ~-:  •  s~    •      '     -&     «*A*-'Z         •     ~^        f  ) 


Fie.  .'vSl.-    Sliii\\!nt:  tlit>  character  JUKI  distribution  of  tlio  potcrliial  sprits  on  the  floor  of 


the  fourth  ventricle  in  the  ease  ol  Sehiehiok  Juirisro  (Nan  Ciies 


of  Dr.  (  leorg'1  V .  Shrady:  "( 'apillary  hemorrhages  were^  noted  on 
the  flos;  of  the  fourth  ventricle,  the  third  \cntricle,  and  the  anterior 
part  of  the  lateral  ventricles.  The  circumvasciilar  spaces  appeared 
to  be  distended  with  serum  and  blood.  The  drain  cortex  beneath  the 
area  of  contact  was  notably  hardened.  The  vessels  of  the  corpora 
Mriata  were  notably  enlarged  at  different  parts  of  their  ramification-. 
The  pons  was  slightly  softened  The  spinal  cord  showed  no  gross 
lesions."  The  abstracted  report  <»f  the  microscopic  findings  of  Dr. 
Spit/.ka  i-  as  follows-:  The  brain,  spinal  cord,  and  peripheral  nerves 
appeared  structurally  healthy  in  every  place  examined  except  in  the 
anemic  and  hardened  areas.  '1  he  hemorrhagic  spots  showed  no  vessel 
alterations.  (The  cytologic  changes  described  by  him  are  of  little 
moment  viewed  from  the  present  day  standards.)  The  vaciiolation  of 
t'tie  ganuTioii  cells  described  an1  'hose  now  recognized  for  the  most  part 
a>  U'liiLi  due  i  )  manipulative  artefacts.  1  ardening.  etc..  and  cannot  !"• 
brought  into  correlation  with  the  later-da\  pathology  ot  the  ganglion 


00  4  MKDICAL    KLKCTRICITY    AND    RONTdKN    HAYS 

<•('!!  (Kwing,  ( loldscheider.  Turner,  Barbacci,  etc.).  The  histologic 
examinations  of  those  paying  the  electrocution  <leath  penalty,  made 
by  Dr.  Van  (iieson  and  others,  are  more  extended,  and  since  newer 
methods  of  accurate  fixation  and  staining  were  in  vogue,  some  clue  may 
be  uained  as  to  the  amount  of  cellular  change.  The  details  of  the  vis- 
ceral examination  do  IKM  nerd  repeating,  since  nothing  abnormal  has 
as  VI-T  been  f.'Utid  in  any  of  the  viscera  related  in  any  way  to  the  method 
of  producing  dratli.  Of  the  cases  examined  by  Van  (iieson.  that  of 
Schichiok  Ju^i^o  may  be  taken  as  a  type.  "The  pia  was  uniformly 
thin  and  modrratrly  congested.  The  blood  was  fluid  throughout.  The 
vessels  at  thr  base  of  the  brain  were  normal.  The  floor  of  the  fourth 
ventricle  at  its  upper  half  contained  some  dilated  vessels,  and  on  the 
left  side  there  were  a  number  of  minute  radiating  petechial  .-pots  from 

1  to  '2  mm.  in  diameter.     These  small  petechial  extravasations  showed 
small  masses  of  extravasated  red  blood-cells,  -it uated  for  the  most  part 
in  the  pei'ivascular  -pace-  just  beneath    the   ependvina."      The   hemor- 
rhage appea'vd  a-  if  a  small  vessel  had   triveti    way,  but    whether  such 
rupture  was  ilur  to  the  current,  to  the  muscular  contortions,  or  to  the 
effects  of  manipulation   are  not    determined   by   the  observer.     In  his 
nummary  of  autopsy  findings,  after  reviewing  the  result    of  a  number 
<if  autopsies,    ])r.    Van   (iieson   notes   the   following:   "(1)    The   passage 
of  an  electric1  current  of  tin-  pressure  employed  in  these  cases  iof  approxi- 
mately  from    1  100  to  1700  volts)    and   in  this  manner  does  not  do   any 
damage   to   any   of  the   internal  organs,   tissues,   or  muscles.      None  of 
these  pails  are  lacerated  or  changed  in  volume;  neither  are  there  any 
liros.-  chemic  or  morphologic   changes  or  alteration  of  their  finer  struc- 
tural   features.      C2)    The    local    thermic    effects    of    the    electrodes    are 
limited  to  the  -carf-skin.      <•'>>   The  occurrence  and  distribution  of  the 

te  hemorrhain'c  spots  are  not  uniform  or  constant  ieatures  in  these 
casi  -  and,  as  they  are  found  after  death  from  a  great  variety  of  causes, 
thev  cannot   properly  be  regarded  as  positively  characteristic  of  death 
i-  method."      (  >bservations  on  man.  wh'di  can  be  Used  to  compare 
those  of  ( 'orrado  on  dogs,   are  still    lacking.      for    man   it    cannot 
be  -aid.   therefore,   that   the  observations  ol   ('orrado  on  dogs 


;ime  when  tin-  uods  were  ilispleased  with  ilie  children  of 
i,   -peculation   has  been  rife   upon   the  question   as  to 
bv  <  lect  ricjty.       I  he  earln-r  ol  »erval  ions  ha\'e  been 
j  i.     and   '.'.'•  are  indebted   to  him   for  a   lar^e  number  of 
\moir_;    t  he   earlier  i  •!  i.-ervi  TS 

'    .     the     "  itlst  at]!  alieoll-     i 
eved    that     t  lie    act  i<  >l\    \\  a- 

i,    •  •         .  '.     at  ion    of    t  he    ii'  r\  on- 


ELECTRICITY    IN    DISEASES    OF    THE    NERVOUS    SYSTEM  535 

amplified.     It  is  worthy  of  mention  in  passing  that  Priestly,  in  1760, 
and   Fontana,  in   1775,  made  a  number  of  elaborate  experiments. 

The  modern  epoch  of  experimental  work  may  be  said  to  have  been 
inaugurated  by  Xothnagel,  of  (iermany,  in  isso,  by  Brouardel,  (! range, 
and  (lariel,  in  1SS4,  in  France,  closely  followed  by  Brown-Sequard  and 
d'Arsonval  in  1SS7,  by  Knitter  in  (lermany,  and  by  Biggs,  Donlin, 
Houston,  Jackson,  Knapp,  Peterson,  Robert,  and  Terry  in  America, 
with  the  later  studies  of  Tatum,  Jones,  Bleile,  Oliver  and  Bolam,  and 
Cunningham.  From  the  pathologic  point  of  view  the  work  of  Xissl, 
Hodge,  Levi,  Lugaro,  Mann  and  Corrado  Ms  to  be  borne  in  mind. 

From  the  foregoing  it  may  be  seen  that  the  entire  possible  theoretic 
ground  was  covered  by  the  earlier  observers,  but  their  investigations 
lacked  the  precise  experimental  evidences  demanded  at  the  present  time. 
The  investigations  of  Xollet.  Crange,  d'Arsonval,  Cirassct,  Dubois, 
I.educ,  and  others  mark  the  earlier  steps  in  the  progress  of  the  elucidation 
of  our  knowledge  concerning  the  phenomena  of  death  by  electricity, 
while  the  investigators  just  mentioned  have  brought  the  question  to 
the  present  time  with  some  definite  conclusions.  d'Arsonval 's  and 
Brown-Sequard 's  earlier  hypotheses  were  received  more  widely  than 
those  of  the  other  writers,  and  have  been  extensively  quoted,  but  within 
recent  times  many  of  their  conclusions  have  been  questioned.  d'Arson- 
val taught  that  death  was  produced  in  either  of  two  ways  or,  perhaps, 
by  the  concurrent  action  of  both:  (1)  By  direct  action,  during  which 
the  disruptive  action  of  the  current  produced  mechanic  alterations  in 
the  tissues  and  thus  altered  their  physiologic  activities.  (2)  By  indirect 
or  reflex  action,  whereby  the  important  nerve-centers  of  the  medulla 
were  affected  in  their  physiologic  functions,  which  induced  death. 

Brown-Sequard  later  amplified  this  indirect  action  in  the  nerve- 
centers.  d'Arsonval  again  brought  up  the  question,  first  promulgated 
by  (irange,  that  the  electric  current  could  brimr  about  effects  simulating 
death,  but  the  subject  could  be  revived  by  artificial  respiration,  to 
which  reference  will  be  made  further  in  the  discussion. 

Cunningham 's  2  very  able  summary  of  the  experimental  data  fol- 
lowing the  epoch  of  d'Arsonval  is  here  very  freely  used.  The  researches 
of  later  writers  (dearly  led  to  the  conclusions  that  neither  the  results 
of  experiments  on  animals  with  strong  electric  currents  nor  the  numer- 
ous reports  of  pathologic  findings  in  the  bodies  of  men  killed  accidentally 
by  the  electric  currents  of  commerce  or  legally  electrocuted  by  the  high- 
tension  current  employed  by  the  authorities  in  Xew  York  State,  are 
in  the  least  corrobat  ive  of  the  hypotheses  of  these  French  investigators 
Cunningham  's  experiments  bear  out  the  conclusions  of  the  later  writers, 
who  find  that  in  the  higher  animals  the  chief  lethal  effect  of  both  the 
ous  and  the  alternating  currents  ^  due  to  their  action  on  the 
Thus,  in  order  to  bring  about  fatal  results  very  much  stronger 
-  are  necessary  when  the  electrode-  are  applied  to  both  sides 
d.  A  complication  of  the  problem  arise-  Irom  the  lact  that 
may  lake  place  in  different  ways,  according  to  the  path  traveled 
•  electric  current.  Thus  the  work  oi  Cunninii'ham  and  others  has 


of  a  strniiii  current    through   the  exposed  brain  and  upper  spinal  cord, 
t  he  let  ha  1  effect    i-  plainl  v  t  he  iv.-ult   of  a.-ph y  xia.  while  in  a  second  class, 
where  the  course  of   even  a  moderate  current    traverses  the  heart   for  a 
brief  period  only,   the  deadly   iv-ult    is  due  to  the  interference  with  the 
coordinating    power  of   the    heart,    which    laker-    place   suddenly   and    is 
permanent,   causimr   the  central    nervous  system   to   die  ot    anemia.      A 
corollary  of  thi-  fact   i-  the  indication  that   death  bv  electrocution  could 
isi  d  in  a  -horter  time  and  with  greater  certainty    it   the  electrodes 
were  -o  pk-t'-ed   ihat    the  greater  jiart   of  the  electric  current    were  made 
.  >  r-e  i  lie  heart  directly.      The  cerebrospinal  arc  -hould  be  included, 
yer.   in   the  path  of  the  current    in  order  to  still   the  respiratory  as 
well  as  the  cardiac  movements.     A.-  pointed  out  m  the  sect  ion  on  Pathol- 
ogy,   the   hear;    in    animal-   killed   by  electric   current    is   found   to  show 
a    condition    ot    "delirium    cordis "   or   "fibrillarv    contraction.  '        This 
at    Nad-  Cunninirham  to  assert   that   death  by  commercial  electric 
currents,  as  well  as  death  by  electrocution,   is  due  for  the  most    part   to 
the  fact    that    the  electric  current    induces  fibrillarv  contractions  of    the 
heart.      The    -ummarv   ot    conclusions   bv    Cunningham    i-    here    given: 
1      Indu-tnal   electric   currents,    which    traverse   the   whole  bodv   trans- 
versely   or   longitudinally    in    sufficient    intensity,    kill    because   fibrillary 
contraction   of   the   heart    is   produced,   and   not,   as   lias   been   hitherto 
-urmi-ed,    by   producing   a    total    paralysis   of  that    organ   or  by  killing 
oiitriirht.      >'2     Such    currents   neither   kill    the    central    nervous   system 
outriirht   nor  paralyze  it  instantaneously.      Death  of  the  nervous  system 
from  -uch  currents  is  due  to  the  total  anemia  following  a  sudden  arrest 
of  the  circulation.      (/>i    In  rare  cases,  when  an  electric  current  traverses 
only  the  cerebrocervical   portion  of  the  nervous  -y.-tem  in  considerable 
intensity  and  for  a  considerable  length  of  time,  it  mav  kill  by  asphvxia, 
consequent    on    a    more   or   less   complete    inhibition    of   the    respiratory 
inent.-.    wliich    occurs    chiefly    during    the    passage    of    the    current. 
Xo  exist  mg  facts  warrant   the  conclusion  that   the  medullary  respiratory 
1  •  nt  i  r  i-  paraly/.ed  or  killed  in  -uch  condit  iohs.1       i  h    I  m  lust  rial  currents 
are    practically    non-lethal    to    frogs    and    turtles,    as    the    condition    of 
lat  ion  <|ii  ickly  and  spontaneously  disappears  from  their  heart  s  after 
the  current  has  ceased  to  pas-.     Such  animal-  can,  of  course,  be  killed  bv 
Mired  a  ppl  i  cat  ion  of  a  current  of   moderate  intensity  or  by 
ine    ij  enormous  volt  age  and  large  intensity.      (o     Si  ron^  elect  ric 
in"1  I  '    !   to  the  surface  of  the  skin   affect    the  heart    in   the  same 

'    irn  nt.-  "i    |es..    strength   do  when    they   are  applied  directly 
ilii     It    may    be    pi  i-sible    l'i  »r   an    elect  ric   current 
1  M-ity  and  elect  romol  ive  lorce  to  produce  instantaneous 
li-rupt  ive  act  ion  or  by  pn  >  an  in.-taiit  aneous 

the   cellular   con.-t  il  uents    of    I  he    I  >oi  |y.       I  ndu-t  rial 
.  di  a-  a    '.  -  •/:    of  I  In  ir  acl  ion  death 

I  he    e\pe|  ience    of     indi\  idual  -     \\  ho     ha  ve     recovered 
hat     -iic'n   a    mode  (,]    1 1( -at  h   is  no!    a 


KLKCTHICI'I'V     IN     DISKASKS    OF    TIIK    NKKYOTS    SYSTKM  .').)  t 

observers  -Cunningham,  Prevost,  and  Battelli  have  come  to  similar 
conclusions,  it  seems  that  the  question  of  the  cause  of  death  by  electricity 
ha-  an  authoritative  answer  in  the  conclusions  just  quoted. 

The  experiments  of  Prevost  and  Battelli,  pat^e  '.M\,  are  of  the 
greatest  value.  They  show  that  with  the  same  position  of  the  elec- 
trodes current-  measured  in  hundredth*  of  volts  kill  by  cardiac  fibrilla- 
tion: and  currents  measured  in  thousands  of  volts  kill  by  respiratory 
paralysis. 


HIGH-FREQUENCY  CURRENTS 

IT  will  be  ivnirinbrivtl  I  hut  when  a  discharge  of  electrostatic  enemy 
take-  place  from  a  I.eyden  jar  the  spark  does  not  represent  a  single 
exchange  of  the  exact  amount  required  to  equalize  the  electric  condi- 
tion of  its  two  armatures.  On  the  contrary,  the  state  of  equilibrium 
is  reached  by  a  series  of  oscillations  back  and  forth  at  the  rate  of  about 
,">i  ii  i.i  H  ii  i  a  second.  This  is  somewhat  analogous  to  the  experiment  with 
the  pith-ball  suspended  between  a  positively  and  a  negatively  charged 
body.  The  ball  swings  back  and  forth,  carrving  each  time  a  fraction  of 
t  he  charge  from  one  and  taking  it  to  the  other  body,  where  it  neutralizes 
that  amount  of  elect  ricity  of  the  opposite  siirn.  This  back-and-forth 
transference  continues  until  both  bodies  are  in  the  same  electric  condi- 
tion. The  oscillations  occurring  in  the  case  of  a  discharge  between 
the  positively  and  negatively  charged  coatings  of  a  l.eydeii  jar.  or  of  a 
battery  of  I.eyden  jars  (acting  as  the  condenser  of  an  induction-coil, 
for  example)  are  infinitely  more  rapid  than  the  oscillations  of  the 


[stratum.     The  relative  electric  condition  of  the  t  \vo 

-  i-M-oes  ."iiio.uiii)  alternations  a  second,  and  if  the  human 

connected  wnh  both  armatures  the  application  i.-  quite  different 

1   .  •  Ivaiiic  or  t'aradic  current.      It   i-  more  analogous  to 

;    breeze  than   to  anvthilig  else,   but    at    the  same  time 

v   '      the  In-!    liiidi-frequency  apparatus  a  current  of  from    100  to  500, 

or   ~o]      '   '          1 1  ii  H  i  of  more,  inilliamperes   pa—e-   through   the   patient. 

I  •       i-urn  •  '   i-  of  incomparably  greater  volume  of  amperage  than  that 

v.  :.:•••  '  •  tween    the   pole-  o|    the   ino-t    powerful   static   machine. 

Tin   •  '  '  •  •   pat  ient  i^  due  to  t he  -elf-induct ion  in  1  he  coil  uniting 

the  t \vo  I..  r-.  which  forms  an  e-v-ent ial  part  ot  all  hiu'li-frequency 

appai    •  .  . 

A   -imp  •_'•  ot    high-tension  electricity   i-  undirectional,  and 

I    _.  . '•  -   the  way  m   whieh   the  strength  of  current    uradually 

dim',: 

I    ji.  '•'>•'>-    '  o-cillatory  chai'acter  Lii\'i'ii  to  t  he  discharge  by 

'ii  o]    I ,i  vden  jar.-  and  a  -olenoii  1, 

I  "he  1 1-  :    t  he  I'urrent  -.  u-ua  ll>"  ret  erred  to  a-  hiu'h-frecjuency 

i'Ai  o  md  Te-la   current  -.  are  of  t  he 


HIGH-FREQUENCY    CURRENTS 


539 


typo  above  described  and  are  called  damped  oscillations.  This  is  lo- 
calise they  quickly  diminish  in  extent  and  die  out,  while  undamped  oscil- 
lations are  uniform  in  extent.  High-frequency  currents  with  undamped 
oscillations  are  referred  to  under  the  heading  of  DeForest  Needle  and 
Duddell's  Singing  Arc  (page  640). 

The  Direction  of  High-frequency  Discharges. — The  discharge  of 
a  Leyden  jar  may  be  made  up  of  millions  of  oscillations,  but  if  it  is 
charged  from  a  non-alternating  source  of  electricity,  like  a  static  machine, 
the  first  and  strongest  oscillation  is  always  in  the  same  direction.  The 
latter  is  also  the  case  with  high-frequency  apparatus  actuated  by  an 
induction-coil,  because  only  the  break  discharges  of  the  latter  are  usually 
operative;  the  weaker  make  discharge  is  unable  to  charge  the  condensers 
to  the  discharging  point  as  indicated  by  the  length  of  the  spark-gap. 

The  Fleming  Rectifier  for.  High-frequency  Currents. — This  con- 
sists of  an  incandescent  electric  lamp  in  which  there  is  a  little  metal 
cylinder  besides  the  carbon  or  metallic  oxid  filament.  Alternating 
high-frequency  currents  can  pass  through  such  a  lamp  in  practically 
one  direction  only.  When  the  filament  is  incandescent  the  partial 
vacuum  in  the  globe  becomes  much  less  resistant  to  the  passage  of  a 
current.  The  filament  acts  as  a  cathode,  while  the  metal  cylinder  has 
a  comparatively  small  surface  for  the  radiation  of  cathode  rays  during 


Currenf 


Neq 


Wehne/t- Infcrrvpff 


. — Apparatus  for  high-frequency  current 


the  period  when  the  current  seeks  to  flow  in  the  other  direction.  Tin1 
incandescent  lamp  is  lighted  up  by  the  current  from  a  storage-battery. 

It  is  necessary  to  recharge  the  Leyden  jar-  e:ich  time  that  they  are 
discharged,  so  as  to  produce1  a  certain  cont  inuit  y  of  effect  in  therapeut  ics. 
The  rate  at  which  the  Leyden  jars  are  charged  and  discharged  is  only 
a  few  hundred  or  a  few  thousand  times  a  minute.  The1  rate  of  o-cil- 
latioti  in  each  individual  discharge  is  million-  of  times  a  second.  It  is 
the  latter  rate  that  gives  the  name  "high  frequency"  to  these  current-. 

At  the  present  time  it  is  not  possible  to  obtain  directly  from  any 
make  of  static  machine  or  induction-coil  a  high-frequency  current.  In 


MEDICAL    ELECTRICITY    AND    Ro.NTCEN    HAYS 


order  id  obtain  a  hiu;h-frequeney  current  fniin  either  the  static  machine 
or  induct idii-cdil  it  i-  nece--arv  1»  have  an  additional  piece  of  appara- 
Mi-.  The  term  "hiii'h-frequency  current"  should  alway-  have  in  addition 
the  name  which  de-imiate-  it-  particular  type.  -iich  as  d'Arsonval  hi<z;h- 
trequeiicv  current  or  Tola  h  mli-f  requencv  current.  In  hath  oi  these 
the  frequency  i-  h'mh,  hut  the  physical  character-  of  the  current  are 
entirely  dilYerent.  Flu'.  •  >•>•>  illu-t  rates  a  complete  arrangement  such 
as  \\ill  be  nece.-sarv  to  produce  t  he  d  'Arsonval  current  from  the  1  10- 
volt  direct  current  :  posit  ive  and  negative  indicate  the  1  10-volt  direct 
ciiri'eiit.  then  comes  an  ordmarv  double  knife-switch  with  fuse. 

Tin      o.-itive  wire  i.-  conducted  to  the  platinum  point  of  the  \\'ehneit, 
inti    .  tpter.     T:.,-  consists  oi   a   <rlass  or  porcelaiii  jar  containing  a   10 
pi  r  n  :.'.  si  ,  itioii  id  sul])huric  acid.      Mounted  on  the  cover  is  a  porce- 
.:  '.:.  -i    m    ha\  inii   an  opening  at   the  lower  end  through  \\hich  is  passed 
:    platinum    wire.     Thi-  usually   ha-  a   mechanism    for   re<ru- 
.:'.:._    the    lenii'tli    which    it    extend.-    beyond    the    porcelain    stem.      Jn 
a  Id  it  ion  'here  i-  ;i  connect  ion  wit  h  t  he  plate  of  lead.      The  plate  of  lead 
i-   connected   \\ith   one   lerimnal  of  the   rheostat:  the  other  terminal  of 
the  rheostat   with   one   terminal  ot    the  ammeter:  the  other  terminal  of 
the  an  mete]    with  one  terminal  of  the  primary;  the  other  terminal  of 
rimary    back    to    the   negative    terminal   of   the    1  10-volt    current. 
Tin    ;  rimary  has  a  core  consisting  of  a  bundle  of  soft  iron  wires.    This 
Aether  by  insulating  materials,  and  on  this  is  wound  the  pri- 
mary wire,  winch   mav  consist  of  one  or  more  la\'ers  of  copper  wire  of 
any    de-ired    diameter.       This    is    placed    in.-ide   of   the    insulating   tube 
may   be   made  of  hard   rubber  or  micanite.      ( 'n   this  insulating 
tube  i-  mounted   the  secondary   winding  of  the   coil:   the  ends  of  the 
secondary   winding  are  now   connected   with    two   sliding    roils:   these 
HI    turn    are   connected   with   the   inside   coatings   of   two    I.e\'('len    iai's. 
Die  outside  coatings  of  the   Leyden   jars  are  connected  by  means  of  a 

''i    heavy  copper  wire  which  is  known 

,•'-     ;i.<      small     solenoid     of     d'Arsonval. 

Ti.'    put  ient    i-  connect  ed  with  t  he  i  wo  ter- 

i-d     I ).     The    si  I'en-ili   of    i  he 

d   to  the   pat  ient    is    renu- 

me;ins    of   the   .-[  i:irk-jrap   and    by 

'  •  •    -.••.•••!    i  •'    current    used    in   the   pri- 

•   of   'h-     induction-coil.      The   current 


•  '          nl  •        ha  me    mi  erni]  *\  er 

d     \  '"!.'.:•.  i   ':  ,'  ci|  I'l'elit 

I     1  10-volt 

•   ' 


HIGH-KREQrKXCY    (TKKKXTS 


f>41 


D'Arsonval    and    Oudin    High-frequency    Apparatus.     D'Arsonval 

also  made  what  is  known  as  the  large  solenoid.  Dr.  Oudin  found  that 
by  connecting  one  end  of  the  large  solenoid  of  d'Arsonval  with  on<-  end 
of  the  small  solenoid  of  d'Arsonval,  as  shown  by  Fig.  33)4,  that  from  1  he 
terminal  0  he  obtained  a  current  entirely  different  in  character  from  the 
ordinary  d'Arsonval  current.  lie  also  found  that  by  adjusting  the  con- 
tact point  between  the  large  solenoid  and  the  small  solenoid  he  was 
able  to  regulate  the  discharge  from  the  terminal  0.  This  led  him  to 
construct  what  is  now  known  as  the  Oudin  .Resonator  (Fig.  335).  This 
you  will  see  is  simply  a  combination  on  one  tube  of  the  small  solenoid 
of  d'Arsonval  and  the  large  solenoid  of  d'Arsonval.  In  this  construc- 
tion, however,  it  is  arranged  so  that  the  contact  F  is  adjustable  and. 
it  is  found  that  when  it  is  placed  at  a  particular  point  the  discharge 
from  terminal  0  is  at  its  maximum.  As  this  contact-point  is  moved 
above  or  below  this  particular  point  the  discharge  decreases.  When 
it  is  adjusted  to  produce  its  maximum  effect  the  apparatus  is  said  to 
be  in  resonance. 

Another  arrangement  for  obtaining  high-frequency  currents  consists 
in  what  is  known  as  a  high-frequency  set.  This  is  designed  especially 
to  operate  from  the  110-volt  alternating  current  (Fig.  33(>).  It  makes 
a  somewhat  more  simple  construct  ion  than  the  usual  induction-coil  ar- 
away  with  the  electrolytic  or  mechanic  inter- 
fact  that  the  current  is  alternating.  In  this 
arrangement,  instead  of  the  usual 
open  magnetic  circuit  type  of  in- 
duction-coil, the  closed  magnetic 
circuit  type  is  used.  The  alter- 
nating current  is  conducted  to 
the  double  pole  knife-switch; 
then  one  terminal  is  carried  to 
either  the  metallic  rheostat  or 
what  is  known  as  an  inductance 
regulator.  This  is  then  connected 
with  one  end  of  the  primary,  the 
other  end  of  the  primary  to  one 
terminal  of  the  ammeter,  the 
other  terminal  of  the  ammeter 


former 


back  to  the  main  line.  The  secondary  circuit  is  connected  with  the 
Leyden  jars,  which  are  connected  with  the  Tesla  coil.  The  current  is 
regulat  ed  by  means  of  t  he  induct  ai  ice  and  the  lengt  h  of  spark-gap.  In 
place  oi  a  IVslu  transformer  the  secondary  can  be  connected  with  an 
Oud m  resonator.  At  the  j>  resent  linn-  ii  is  not  possible  to  obtain  a  hiirh- 

t 

frequency  current    in   any  other   than   l>\    the   above  or  similar  means. 


542 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


to  have  the  arrangement  of  d'Arsonval,  the1  arrangement  of  Tesla,  or 
that  of  Oudin  in  addition  to  the  static  machine  or  coil.  I  call  atten- 
tion to  this  particularly,  as  some  manufacturers  claim  that  their  static 
machine  will  give  a  high-frequency  current  direct.  They  use  in  con- 
junction with  the  static  machine  a  vacuum  electrode,  and,  as  a  rule,  it 
is  connected  up  as  >ho\vn  by  Fig.  338.  When  the  vacuum  electrode 
is  placed  in  contact  with  the  patient  it  will  light  up  with  a  violet  color 
thr  >ame  as  it  would  it'  attached  to  a  high-frequency  apparatus,  but 
the  sensation  produced  in  the  patient  is  entirely  different,  being  of  a 
vibratory  character;  it  i>.  in  fact,  when  used  in  this  way  in  conjunction 
with  a  static  machine  simply  a  method  of  applying  the  wave-current 
by  means  of  vacuum  electrodes.  This  cm-rent  has  a  certain  therapeutic 
value,  but  should  not  be  called  a  high-frequency  current.  It  will  be 
referred  to  as  vibratorv  current  l Figs.  338  and  339). 


Fill.  ;W<s.—  Cuiiiici  l  i.in  \\hcn  vibratory  current  is  u>ed  with  .-tittir  machine. 

( )ne  very  simple  test  to  demonstrate  physically  the  difference 
between  this  current  and  either  form  of  high-frequency  current  is  to 
have  the  subject  in  good  contact  with  the  metal  part  which  holds  the 
vacuum  electrode.  When  this  is  connected  with  the  static  machine 
as  above  de.-cribed.  you  will  experience  a  very  disagreeable  shock, 
wherea.-.  when  it  is  connected  with  a  high-frequency  current  no  sensation 
other  than  that  of  having  a  slight  feeling  of  warmth  will  be  experienced. 
mi  electrodes,  are  used  in  this  same  way  with  an  induction-coil, 


1  m  tii  '  tji.M  wiicii  vinriitorv  cum-nt   i1-  IIM-I!   fr 


'!i   oi    •    irrent    beniir  regulated   bv   the  distance  A   and    B  an 


te  the  fact   that  this  current   is  not  a  hiirh-fn 


nece-.-arv   to   in.-ert    between   the  electrode  an< 


in-i  rument  •  •     as    t  lie    oscii  n 


HIGH-FREQUENCY    CURRENTS 


543 


340  shows  tliis  in  circuit  with  a  Tcsla  current.  With  the  static  machine 
you  will  notice  that  the  violet  color  is  all  on  one  side  of  the  center, 
whereas  when  connected  with  the  Tesla  current  it  shows  the  violet  color 
on  both  sides  of  the  center. 

An  induction-coil,  such  as  is  suitable  for  x-ray  work,  is  very 
desirable  for  high-frequency  apparatus.  A  12-inch  coil  is  about  the 
best,  and  can  be  used  no  mutter  what  the  nature  of  the  interrupter 
and  the  source  of  the  primary  current  are.  The  primary  winding 
of  the  coil  should  have  a  large  number  of  turns  so  as  to  give  great 
self-inductance  and  a  proportionately  heavy  secondary  discharge. 
In  this  case  the  actual  spark  length  seems  to  be  of  less  importance,' 
than  the  "fatness"  of  the  spark,  and  in  my  own  apparatus  the  best 
results  are  obtained  with  an  adjustment  which  will  produce  a  u'-inch 
flame  between  the  poles  of  the  coil  when  the  high-frequency  apparatus 
is  disconnected  from  them.  Kvery  x-ray  coil  should  have  a  variable 
primary  winding,  and  if  this  is  the  case  it  will  be  easy  to  adjust  it 
for  the  best  high-frequency  work.  A  desideratum  is  an  interrupter 
which  will  produce  a  sufficiently  heavy  spark  with  only  one,  two  or  three, 
four,  or  five  amperes  of  primary  current.  This  means  less  wear  upon 
the  apparatus  and  longer  continuous  use  without  detriment. 


OS-cope    demonstrates    oscillatory    character 
current. 


)f    Tesla,    high-frequency 


With  alternating  currents  an  .r-ray  coil  with  one  of  the  rectifiers 
described  on  page  723  works  very  well,  or  (iaiffe's  transformer  outfit 
may  be  used. 

Gaiffe's  transformer  outfit,  without  any  interrupter,  for  x-ray 
and  high-frequency  apparatus,  is  described  in  detail  on  page  744. 
The  ordinary  alternating  electric-light  current  passes  through  a  primary 
wire,  which  surrounds  one  part  of  the  circumference  of  a  magnet  which 
forms  a  complete  ring.  Around  another  or  the  same  part  of  the  ring  is 
wrapped  t  he  secondary  wire.  The  voltage  in  the  secondary  wire  is  as  many 
times  the  original  110  volts  as  its  number  of  turns  of  wire  is  times  the 
number  of  turns  in  the  primary  wire.  The  magnetic  ring,  with  its 
primary  and  secondary  windings,  constitutes  a  transformer:  in  this 
case  a  step-up  transformer,  since  the  voltage  is  increased  by  it.  The 
switches  and  liquid  rheostats  and  condensers  are  all  arranged  as  for 
./•-ray  work,  but  the  two  ventl'il  tubes  need  not  be  used.  Connection 
is  made  from  the  two  ./--ray  terminal-  to  the  high-frequency  apparatus. 


MEDICAL    ELECTRICITY    AND    KONTCEN     HAYS 


Such  an  outfit  will  work  continuously  for  an  indefinite  length  of  time 
and  with  ab.-olute  uniformity.  It  is  the  very  best  for  use  with  an  alter- 
nating current,  and  mav  prove  to  be  so  much  better  than  an  induction- 
coil  -ind  interrupter  that,  even  with  a  direct  current,  it  will  be  advantage- 
ous to  use  thi-  outfit  in  connection  with  a  motor  generator  by  which 
the  direct  current  is  made  to  produce  an  alternating  one. 

The  d'Arsonval  transformer  is  one  of  the  :-imple-t  and  best 
form-  of  apparatus  for  the  production  of  high-frequency  cur- 
rent-. In  ihis  apparatu-  the  poles  of  an  ordinary  induction-coil, 
such  as  an  .r-rav  coil,  are  connected  with  the  inner  coatings  ot  two  large 
beydeti  jars,  and  these  inner  coatings  are  further  connected  with  tin- 
two  terminal-  of  an  adjustable  and  enclosed  (muffled)  spark-gap,  or 
better,  a  serie-  of  several  short  gaps.  The  outer  coalings  of  the  Leyden 
jars  are  connected  with  each  other  by  a  solenoid,  which  is  a  coil  of 
heavy  wire  wound  in  the  form  of  a  hollow  cylinder.  The  turns  of  this 
wire,  about  twenty  in  number,  are  about  \  inch  apart,  and  require 
no  further  insulation  from  each  other.  Conducting  cords  also  pass 
to  the  patient  from  turns  near  the  ends  of  the  solenoid.  One  of  these 
cords  terminates  in  an  ordinary  metal  handle,  which  is  usually  held  by 
the  patient.  The  other  sometimes  terminates  in  an  insulated  handle 
held  by  the  operator.  This  has  a  metallic  socket,  into  which  fit  elec- 
trodes of  metal  or  of  glass;  t  he  lat  ter  are  vacuum  I  ubes  of  various  kinds, 
or  this  wire  may  terminate  in  the  metallic  plate  of  an  autocondensation 
couch,  or  neither  wire  may  go  to  the  patient,  but  they  may  lead  to  op- 
po-ite  extremities  of  an  aut  oconduct  ion  cage. 

The  poles  of  the  .r-ray  coil   are  widely  separate^!;  the  points  of  the 
spark-gap  o!    the  d'Arsonval  t  ran.-tormer  are  separated  about  one-third 
or  one-half  inch  and   a   sufficient   current    is  turned    on  to   cause  a  rapid 
and   uniform   succession   of  sparks  aero.-.-   the  spark-gap.      The   latter  is 
muffled,   enclosed   in   a  glass  cylinder  or   vulcanite   box    to    deaden   the 
tioise.       Nitric  acid   fume-  are  generated   by   the   passage  of  these  sparks 
through  the  nitrogen  of  the  air  and   a    metallic  nitrate  is  deposited  upon 
the  interior  of  the  glass,  which  eventually  interfere-;  with  the  -park-gap 
by  short  circuit  ing  and  requires  to  be  cleaned  out .      The  pat  ient ,  holding 
one  of  the   handle-   m   one   hand   and   a    vacuum   electrode   m   the  other, 
\\ill  experience-  no  sensation  but    that   of  a  gradually  developing  warmth 
I  he    vannim   electrode.      This   is   true  even    wilh   a    current    of  200 
to  .  )i  ii  i  ti  ilha  mperes  pa.- -I  ir_:  t  h  rough  the  pa  t  len  t  .       1  he  vacuum  elect  rode 
become-    lighted    up    bv    wave-    of    violet     light     pa.-Hiig    down    inside    the 
ng    each    other   at    a    rate    which    seems    to    be    the   same   as 
In     -parks  aero--  the  -park-nap.      This  is  ordinarily  at    the  same 
lerrupter.      A   hot-wire  millianipere'ineter,  place-el  m  -cries 
patient,    -hows    the   strength    o|    l  he   current.       If   the   electrode 
tacl    with   the  skin,  sparks  may   be  -een   beginning  at 
nee    and    pas-ing    along    tin-   out-ide   of    the   glass   to    the 
n  a  product  ion  of  o/o ne  from  I  he  -a  me  -parks.      Tin-re 
r-i  mi  i !    wi  ill    tin-    pa  i  lent  .       lie   i-   on    a   .-hunt    circuit 
1  he   fact    t  hat    lie  get  -  any   ni  rrenl    al    all    i-  due  t  o 
ii     1  I  ie    -oli  Hold    developed     bv    1 1  -   sell'-iiie Inct  loll . 
itide-cenl     lamp    hv    direct     conduction    of    high-fre- 
o    pi  :  -on-    hoi'  I   each    a    mi  I  allic   <  !'  -cl  n  n  |e   from   one 
•  al    t  raii-forniei    and    each   bv   hi-  other  hand   holds 

'_'     to    all     elect  He     lamp    -ll-pended     bet  \\  een     them. 


HIGH-FREQUENCY    CURRENTS 


545 


The  lamp  may  light  up  brightly  and  still  the  persons  experience  no  sen- 
sation from  the  current  passing  through  their  bodies. 

The  author'*  vacuum  electrodes,  with  a  vacuum  of  about  , -,/„„  of  an 
atmosphere,  are  made  with  a  leading-in  wire  passing  just  through  the 
thickness  of  the  glass  at  the  point  where  the  tube  has  a  screw  thread. 
The  tube  is  screwed  into  a  metal  socket  well  up  inside  of  a  special 
handle  of  hard  rubber,  which  is  completely  insulated.  No  current  can 
be  received  by  either  the  patient  or  the  operator  from  any  part  of  the 
handle.  The  glass  electrode  is  the  only  bare  part,  and  contact  with 
that  is  not  disagreeable  at  all,  although  the  current  may  be  sufficient 
to  light  up  a  16-eandle-power  lamp  placed  in  circuit  with  the  patient. 
Those  for  the  surface  of  the  body  are  simple  tubes  with  a  dome-shaped 
extremity,  while  some  of  those  for  the  mouth,  rectum,  or  vagina  have 
an  insulated  stem  where  they  enter  the  cavity  and  where  sparks  might 
occur  from  the  contart  being  less  perfect  than  full  her  in  where  it  is  sur- 
rounded by  mucous  membrane.  This  insulation  is  accomplished  by 
having  the  vacuum  tube  very  small  along  this  portion  of  its  length,  and 
having  an  air-space  between  it  and  an  outer  tube  of  glass,  which  is 
of  uniform  caliber  with  the  portions  of  the  electrode  above  and  below 
it.  The  waves  of  light  may  be  seen  in  the  upper  and  lower  and  the 
narrow  central  portion,  but  are  absent  from  the  outer  jacket  sur- 
rounding the  latter,  and  no  current  is  obtained  by  touching  this  outer 
jacket. 

Other  vacuum  electrodes  are  made  without  any  wire,  the  current 
being  of  sufficiently  high  tension  to  penetrate  glass  of  any  reasonable 


FiK.  341.— Auto 

thickness.  In  this  case,  to  obtain  a  sufficient  current  the  glass  should 
be  quite  thin  and  there  should  be  a  large  area  of  contact  with  the 
metal  handle  to  avoid  overheating  the  glass  at  that  place.  Different 
forms  of  metal  and  glass  electrodes  for  various  parts  of  the  surface 
and  for  1  he  different  orifices  of  the  body  are  made,  and  will  be  considered 
in  detail  in  the  section  upon  the  Therapeutic  Application  of  High-fre- 
quency Currents  (page1  f>">S). 

The  autocondensation  couch  consists  of  a  sheet  of  metal  or  a 
flat  mass  of  wires  connected  with  one  pole  of  the  d'Arsonval  trans- 
former, on  top  of  which  is  a  thick  insulatiim  mattress  upon  which  the 
patient  lies.  The  handle  from  the  other  pole  of  the  d'Arsonval  trans- 
iormer  is  held  in  the  patient's  hand,  and  when  the  apparatus  is  in  opera- 
tion a  cm-rent  of  100  to  100  or  SOO  milliamperes  is  indicated  by  the  meter 
which  is  in  circuit  with  the  patient.  The  patient  becoming  charged  with 


546  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

one  kind  of  electricity  and  the  metal  plate  with  electricity  of  the  oppo- 
site sign,  and  the  insulating  mattress  intervening,  form  a  complete  con- 
denser on  the  same  principle  as  a  Leyden  jar.  The  patient  corresponds 
to  the  external  metallic  coating  or  armature  of  the  Leyden  jar,  and 
each  time  the  patient  and  the  metal  sheet  become  overcharged  and  a 
discharge  takes  place  across  the  muffled  spark-gap  of  the  d'Arsonval 
apparatus  the  patient  undergoes  a  very  great  number  of  electric 
oscillat  ions. 

In  another  couch  which  the  author  has  used  the  principle  is  rather 
that  of  atitoconduct  ion.  The  couch  consists  in  some  cases  of  a  wire 
mattress  in  two  parts,  very  heavily  insulated,  each  end  being  connected 
with  one  of  the  poles  of  the  d  'A  rsoiival.  High-frequency  currents  are 
produced  in  the  patient  by  induction  from  the  wire  couch  without  any 
metallic  connection  reaching  the  patient. 

Another  couch  consists  of  indurated  fiber  an  eighth  of  an  inch  thick, 
up"ii  the  back  of  \vhich  is  a  sheet  of  ./'-ray  metal,  and  this  covered  again 
with  a  light  insulating  cloth.  This  is  made  in  two  section.-,  hinged 
together  with  (juite  a  wide  insulated  separation,  the  wire  from  one  pole 
of  the  d'Arsonval  passes  to  one  metal  sheet,  and  the  wire  from  the 
other  pule  to  the  other  metal  sheet.  A  convenient  way  to  use  it  is  to 
place  it  on  an  ordinary  chair  so  that  one  part  forms  the  seat  and  another 
the  back.  There  should  be  no  metallic  parts  to  the  chair  except  the 
ordinary  nails  and  tack.-.  Before  the  patient  is  seated  upon  this  the 
current  shown  by  a  millianiperenieter  in  circuit  with  the  couch  may 
be  15d  milliamperes.  and  the  moment  the  patient  sits  down  it  may 
increase  to  over  100  milliamperes.  This  is  without  any  sensation. 
Through  the  patient'.-  back  lie  receives  an  induced  charge  from  one 
metal  sheet,  and  through  the  lower  part  of  the  body  and  the  thighs  he 
receives  an  induced  charge  of  the  opposite  sign  from  the  other  metal 
-heet.  Tim-,  aii  extremely  rapid  series  of  condenser  discharges  is 
produced  through  the  patient's  body.  If  a  stronger  current  is  turned 
•'\:.  5oi  i  or  di  ii  i  milliamperes.  considerable  brush  discharge  parses  to  the 
patient  through  the  indurated  liber.  While  this  is  not  disagreeable 

mf  il  for  a  -hort  time,  it  is  better  to  avoid  it  in  general. 
\\iih   the  aiitocoiidensat ion   couch   used   bv   the  author  the  current 
in;t\    be  between    1 00  and  500  milliamperes  when   the  patient    is  seated 
poii    .'    and    ihu-   bv  a  conductor  effect   facilitate-  the  discharge.      And 
nt    leaves  the  couch  the  current    \\;l]  be  seen  to  diminish 
'•V    I'll)  nuiliamperes.       It    will   be  remembered   that    if  two   l.evden 
om   the   prime  conductors    ot    a   static   machine  and   a 
ds  the  outer  lavej-.-  of  the  jars,  treinendouslv  powerful 
pa.--  bet  ween  the  pole-  ot   1  lie  coll.      These  are  a   t  housaild 
••     •    the  discharge  which  take-  place  when  ihe  rod  i.-  dis- 
tlie  outer  laver-  of  th1'    Leyden   jars.      The   wonderful 
:    takes    place   between    the    pole.-   of   tin-   .-tat  ic    machine 
•     place  i-  accompanied  and.  one  can  almost   say.  pro- 
i '•  discharge    \\hich    passe.-    through    the 
ouch    in   question    ihe  lead   plate-  to  \\ 
|iiencv  coil  correspond   to  ihe  inn 
in   the  experiment    with   the  stati 
•  -pond-  to  the  outer  layers  of  the  two 

'hi'Tii.       The    difference    between    th 


HIGH-FREQUENCY    CURRENTS  547 

couch,  with  and  without  the  patient,  shows  roughly  the  amount  of 
electricity  induced  in  and  discharging  through  the  patient. 

The  autoconduction  cage  is  a  hollow  cylinder  formed  by  a  coil  of 
wire  the  turns  of  which  are  widely  separated.  The  cage  may  he  placed 
vertically,  and  the  patient  stand  or  sit  inside  of  it,  or  it  may  he  horizon- 
tal and  surround  a  table  top  on  which  the  patient  lies.  Its  two  extremi- 
ties are  connected  with  the  two  poles  of  the  d'Arsonval  transformer, 
and  when  in  operation  high-frequency  currents  are  produced  in  the 
patient  without  his  being  in  metallic  connection  with  any  part  of  the 
apparatus. 

Measurement  of  High-frequency  Currents  in  Autoconduction. — The 
niost  practical  measurement  of  the  strength  of  the  current  induced  in 
the  interior  of  the  autoconduction  cage  is  in  (Jausses,  as  described  by 
Doumer.  and  depends  upon  the  amount  of  current  induced  in  a  loop  of 
wire  placed  inside  the  autoconduction  cage  and  parallel  with  its  turns. 
The  currents  are  alternating,  and  the  amperemeter  is  usually  a  thermic 
or  hot-wire  instrument.  The  graduations  may  be  directly  in  (iausses. 

The  frcf/itenci/  of  the  oscillations  in  high-frequency  currents  may  be 
measured  by  Feme's  ondomctcr.  This  has  a  certain  length  of  wire, 
which  may  be  placed  parallel  with  and  close  to  the  wire  through  which 
the  oscillatory  current  is  passing.  The  wire  mentioned  forms  part  of  a 
circuit  which  also  contains  a  self-induction,  a  condenser  of  adjustable 
capacity,  and  a  hot-win1  milliamperemeter.  The  capacity  of  the  con- 
denser in  the  ondometer  is  regulated  so  thai  the  maximum  current  is 
registered,  indicating  oscillations  synchronous  with  those  in  the  circuit 
to  be  tested.  The  condenser  is  graduated  in  figures  representing  the 
number  of  oscillations  per  second.  This  is  between  300, 000  and  1)00,000 
for  most  high-frequency  work. 

Kficd*  of  Autoconduction  and  Autocondenxation. — With  both  the 
aut  (condensation  couch  and  the  autoconduction  cage  the  patient  does 
not  feel  any  electricity,  but  its  presence  may  be  proved  by  drawing 
-park-  from  any  part  of  his  body  and  even  a  slight  violet  brush  dis- 
charge may  take  place  between  the  patient'-  two  hands  if  one  finger  of 
each  are  brought  lightly  together.  A  variety  of  experiments  may  be 
performed  with  incandescent  lamps  or  telephones  to  demonstrate  the 
presence  of  electricity  on  every  portion  of  the  pal  lent  '.-  surface. 

To  liu'ht  an  incandescent  lumj)  by  autoconduction  it  is  only  necessary 
to  connect  it  by  a  loop  of  wire  held  in-ide  a  solenoid  traversed  by  high- 
frequency  currents.  A  vacuum  tube  approached  to  the  solenoid  lights 
up.  Any  body  inside  a  solenoid  is  itself  traversed  by  high-frequency 
current  -. 

Piffard's  Hyperstatic  Transformer  Fig.  342).-  This  apparatus  is 
devised  to  obtain  high-frequency  currents  from  the  static  machine. 
Two  medium-sized  I.evden  jars  have  their  inner  coatmir-  connected 
wit  h  t  lie  t  wo  prune  conductors  of  the  static  machine.  The  sj iark-u;a | >  i- 
obtained  by  separating  the  poles  of  the  static  machine  about  an  inch. 
The  outer  layers  of  the  Ley  den  jars  are  connected  with  the  extremities 
of  a  small  solenoid,  at  the  end-  of  \vhich  are  binding-posts.  With  the 
plates  revolving  at  the  rate  of  :>()()  or  .'!">0  tunes  a  minute  there  is  an 
etlluve  to  be  felt  from  both  binding-posts,  ihat  corresponding  to  the 
positive  poie  of  the  static  machine  beiim'  the  stronger.  For  mild 
applications  a  vacuum  elect  rode  i-  con  nee  ted  with  only  one  1 1  he  positive  i 
pole  of  the  hyperstatic  transformer.  For  a  more  active  effect  the 


MEDICAL    ELECTRICITY    AM)    RONTGEN    RAYS 

patient  holds  a  metal  electrode  connected  with  one  pole  while  a  vacuum 
or  a  metal  electrode  from  the  other  pole  is  applied  to  the  region  to  be 
treated.  Pif'fard's  own  belief  is  that  the  hyperstatic  current  is  chiefly 
valuable  for  a  local  effect,  as  in  chronic  ec/ema,  and  that  it  cannot  take 
the  place  of  the  d'Arsonval  current,  with  its  vastly  urea  tor  amperage, 


for  the  production  of  constitutional  effects.  The  static  machines  usu- 
ally found  in  Europe  scarcely  amount  to  more  than  laboratory  toys.  It 
i-  only  the  large  American  machines  with  eight  or  more  pairs  of  plates, 
30  inches  or  more  in  diameter,  that  are  suitable  for  this  therapeutic 
application. 

THE   OUDIN  RESONATOR 

\\c  come  now  to  another  type  of  high-frequency  apparatus  in  which 

a  conden-er  discharge  is  passed  through  one  or  more  turn-  of  an  as- 
ccnding  -piral  of  which  the  upper  end  is  free.  The  -elf-induction  in  the 
-piral  increases  toward  its  extremity,  where  the  tension  is  such  that  the 
wire  give.- off  an  efrluve  or 'brush  discharge  of  -everal  inches  into  the 
emptv  air  and  a  much  more  powerful  one  if  -ome  conductor  like  the 
human  body  apnroache-  it.  Quite  a  u-ual  model  i-  shown  in  Fig.  343. 
The  pule-  of  the  induction-coil,  or  static  machine,  or  transformer,  are 
connected  to  the  inner  armatures  of  two  Leyden  ja>'-  'the  condensers!, 
and  t  he-e  -aine  inner  armature-  are  connected  with  a  muffled  spark- 
uap.  The  outer  armature.-  of  the  two  Leyden  jars  are  connected 
I  >\  a  -olenoid  ju-t  a-  in  the  d'Arsonval  Iran-former,  but  in  addition 
a  wire  pa--e-  Mom  one  end  of  the  -olenoid  to  the  lower  extremity 
of  l  he  vertical  coil  the  <  hidin  resonator  proper'  ;1iid  another  wire 
pa--e-  Mom  an  adju-table  contact,  u-ually  near  the  middle  of  the 
et  1 1  .id.  to  aiiot  her  adjustable  contact  with  t  he  <  hid  in  resonator. 
.  .  li!  t  h  of  t  he  distance  from  its  lower  pole.  The  adjust- 
ment between  i  hi  amount  of  -elf-induct  ion  in  the.-e  two  coils  produces 
harmoit\  ectric  oscillation-,  and  it  i-  trom  hi-  resonance  that 
t  he  app.-i :  : '  .  eri\-i-  it-  name.  In  order  that  tin-  -hall  work  we'll  it 
i-  nece--ar\  to -e  the  proper  turn  in  the  -piral  to  which  the  second 


HIGH-FREQUENCY    CURRENTS 


549 


Leyden  jar  shall  he  connected.  This  is  done  by  starting  the  Ruhmkorff 
coil  and  t hen  making  a  connection  \vn  h  t he  different  1  urns  successively. 
Another  t'onn  of  resonator  used  by  the  author  is  made  in  the  shape 
of  a  flat  spiral,  the  outer  end  of  which  is  soldered  to  the  next  turn  of  the 
wire  and  is  also  connected  with  one  end  of  the  small  solenoid.  The  ot  her 
end  of  the  small  solenoid  may  lie  connected  with  either  the  second,  third, 
or  fourth  turn  of  the  spiral.  The  center  or  inner  end  of  the  flat  spiral  is 
free,  and  corresponds  exactly  with  the  upper  free  end  of  the  upright 


i'ig.  3415. — The  Oudin  resonator  and  d'Arsonvul  hiirh-frrqupnoy  apparatus. 

cylinder  type  of  Oudin.  In  my  model  the  spiral  is  30  inches  in  diam- 
eter, and  there  are  binding-posts  at  different  parts  to  enable  various 
strengths  of  discharge1  to  be  used.  The  eflluve  from  the  middle  of  the 
spiral  is  very  powerful.  The  coil  is  large  and  heavily  insulated  and  the 
turns  of  the  spiral  are  about  1  inch  apart. 

The  Oudin  resonator  is  intended  principally  for  unipolar  applications, 
either  as  an  efHuve  from  pointed  electrodes  held  at  a  distance  from  the 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


surface  of  the  body,  oi1  by  din-el  application  from  vacuum  or  other 
electrodes  applied  to  the  skin  or  mucous  membranes. 

It  requires  at  least  a  I'J-inch  induction-coil  to  actuate  an  Oudin 
resonator  to  the  best  advantage. 

Bipolar  applications  with  the  Oudin  resonator  may  be  made  by  the 
etthive  from  1  \vo  i-esonatoi-s  applied,  for  instance,  to  the  front  and  back 
of  the  chest,  or  the  metal  plate  of  an  autooondensation  couch  may  bo 
connected  \\iih  one  resonator  and  an  ehMuve  from  another  resonator 
be  applied  over  the  patient.  When  two  resonators  are  used  the  lower 


|e  of  '  a  en  :-  at  t  ached  to  the  opposite  end.-  of  t  he  small  :-olenoid.      When 


autocondensat  ion    couch    the    full 


'    -  t  he  outer  armat  ure>  ol  t  he  I  .ev den  jars  are  connect  ed 

hi    Oudin    resonator,   one   \\iih    ilie   lower   pole  and   the 

In  r.      The-e  lower  tin1!:-  oi  i  he  resonator  produce 

!:''•'••    ;,,    the    -mall    solenoid    and    enable    tin-    to    be    di.-pensed 


TESLA    HIGH  FREQUENCY   CTKRhNT 

'h'am    '!>!-  from  tin     i  Ill-volt   dii'eci  i-iirrent   it   i.-  neces- 

i  rat  u>  a>  de-cnbi-d  tor  t  lii-  d   A  r.-onval  current .  and 

ddi'ioii.  a       !IM\VII  \<y  I-"m'.  '.'>'. >*'<.  p.  oil.  and   insulating  tube  is  placed 

i  he  -mall  solenoid  of  d'.\ ix »ii va  1 .  and  i  hen  a  winding 

ed  either  in-ide  of  the  tube,  if  i  he  tube  is  placed 


HIGH-FREQUENCY    CURRENTS  551 

inside  of  the  small  solenoid,  or  outside  of  the  tube  if  the  tube  is  placed 
over  t  lie  small  solenoid.  As  described  by  Tesla,  them  is  in  addition  to  this 

insulating  tube  a  liquid  insulator  in  the  form  of  oil.  but  as  the  apparatus 
is  ordinarily  constructed  for  medical  purposes  the  oil  insulation  is  not, 
required.  From  the  terminals  ('  the  Tesla  high-frequency  cm-rent  will 
be  obi  allied. 

The  Tesla  transformer  is  a  source  of  extremely  high  potential 
discharges  at  a  rapid  rate,  and  can  be  used  to  excite  an  Oudin  resonator 
for  medical  purposes,  but.  is  more  suitable  for  exciting  Hertzian  waves 
in  wireless  telegraphy.  The  transmitter  for  the  latter  consists  essen- 
tially of  a  Tesla  transformer  and  an  Oudin  resonator,  whose  upper  ter- 
minal is  carried  to  the  top  of  the  mast  of  a  ship  or  of  a  high  flag-pole 
if  on  shore.  The  Tesla  transformer  consists  first  of  a  primary  coil, 
through  which  (lows  a  rapidly  interrupted  current  of  high  voltage  from 
an  induction-coil  or  from  a  step-up  transformer;  this  primary  coil  is 
surrounded  by  a  secondary  coil,  consisting  of  a  large  number  of  turns  of 
very  fine  wire,  and  the  originally  high  tension  is  enormously  multiplied. 
Other  essential  parts  of  the  Tesla  transformer  are  the  condenser  and  an 
adjustable  spark-gap  between  the  extremities  of  the  primary  coil. 
The  condenser  and  spark-gap  serve  the  same  purpose  here  as  in  the 
d'Arsonval  transformer  to  be  described  later.  Both  the  primary  and 
the  secondary  coil  and  the  condenser  are  immersed  in  oil  to  prevent 
sparking  from  one  coil  to  the  other.  The  terminal  pole.-  of  the  '1  esla 
transformer  are  wide  apart,  and  the  discharge  from  them  is  of  alto- 
get  her  ext  raon  linary  power.  To  excite  an  <  hid  in  resonator  one  terminal 
of  the  Tesla  t  ransformer  is  grounded  and  the  oi  her  terminal  is  connected 
wit  h  t  he  Oudin  resonator  at  the  height  found  to  produce  the  best  results. 

1  )'•.  Henry  '  !.  Piffard  of  this  city  modified  the  original  Tesla  apparatus 
so  as  to  make  it  applicable  to  any  static  machine,  and  in  order  to  differen- 
tiate it  from  an  apparatus  operated  by  a  coil  he  called  it  the hyperstatic 
trail-former.  At  the  present  time  we  have  practically  only  two  forms 
of  high-frequency  currents  in  use  in  medicine.  These  are  t  he  d  '  Arson val 
high-frequency  current  and  the  Tesla  or  Oudin  high-frequency  current. 
The  therapeutic  applications  of  the  Tesla  and  Oudin  currents  are  identical, 
the  other  physical  characters  are  also  identical,  the  only  difference  being 
in  the  mechanic  construction  of  the  apparatus  itself.  In  a  general 
way  the  therapeutic  applications  of  the  two  forms  of  high-frequency 
currents  are  as  follows:  The  d'Arsonval.  which  is  a  low-voltage  high- 
frequency  current  of  comparatively  high  amperage,  is  used  for  its  con- 
stitutional action.  The  Tesla  and  Oudin  resonator  current  s  are  currents 
ot  hiirh  irequency.  high  voltage,  and  comparatively  low  amperage. 
They  are  used  mostly  for  their  local  and  reflex  effects. 

Violet-ray  Treatment. — This  is  a  term  which  has  been  used  very 
carelessly,  as  there  is  reallv  no  such  treatment.  It  has  usually  been 
applied  when  a  vacuum  electrode  is  used,  without  regard  to  whether 
the  current  was  a  high-frequency  one  or  simply  a  high-voltage  one. 
< 'it  her  beinu'  sufficient  to  cause  t  he  violet  color  to  appear  in  t  he  elect  rode. 

Ultraviolet-ray  Treatment.  This  is  another  term  which  has 
been  very  carelessly  used,  it  bein<r  applied  when  a  vacuum  electrode  i> 
used.  As  the  ultraviolet  rav  will  not  penetrate  the  thinnest  piece  of 
mica  or  celluloid,  the  results  which  have  been  obtained  when  using  the 
vacuum  electrode  are  due  to  the  form  of  current  applied,  and  not  so 
much  to  the  ultraviolet  rays,  which  are  Liiven  of)'  from  the  sparks  outside 


•'•'-  MEDICAL     ELECTRICITY    AND    RONTdEN     HAYS 

<>f  the  electrode.      AYhenever  a  spark  takes  place  there  is  a  generation  of 
ultraviolet  rays.  but  these  rays  are  invisii)le  to  the  human  eye. 

All   hijrh-fivquency  current-  are  o<cillatin^.  lmt  all  alternating  cur- 
rent- are  not  oscillating,  as  shown  hv  Fi<r.  315. 


Monolith  Condensers  for  High  Frequency.  -These  arc  condensers. 
mad*1  ill  th.i-  form  of  Hat  plates  of  ulass.  between  which  are  the  metallic 
sheets  which  form  the  armatures  of  the  condenser.  The  ^lass  plates 
:  beyond  the  ed»-e  of  the  metal  and  are  soldered  together  by  a 
ceini'iit  of  a  d  a^s-like  consistence.  Loss  of  electricity  is  prevented 
inurh  bett'-r  than  by  air  or  oil  insulation  of  the  armatures.  The  capacity 
of  each  i.-  about  tin-  same  as  that  of  a  larnv  Leyden  jar:  the  condensers 
are  Hat  disks  about  1  inch  thick  and  about  s  inches  in  diameter.  They 
may  be  combined  in  scries  or  in  quantity,  and  may  be  placed  in  the 
bottom  of  the  resonator  for  instance.1 

In  many  <  lermun.hijih-frequency  a  p  pa  rat  u<  t  h«'  adjust  able  spark-^aji 
i-  in  th^  self-induction  line  between  the  two  external  armatures  of  the 
condensers  1-  m.  346;  ui-tcad  of  between  their  internal  armatures  as  in 
the  d'Arsonval  arid  Oudin  and  (iuilleminot  arran.trements. 

METHODS   OF  APPLYING  HIGH-FREQUENCY  CURRENTS 

Applications   from   a  Small   Solenoid.    -Instead  of  wires  leadinir 

the  external  armat ures  to  at.  fiutoconduction  ca<re.  two  wires  lead 

from    different    turns   of   the  small   solenoid   directlv   to   two   electrodes 


appli'-d   ti  tient,     The  effect  is  due  chiefly  to  the  small  solenoid 

•  f  heavv  wire  which  extend-   between   the  outer 

arm  .  Mjn       if  t  hi'    •  >m  !•  -n-ers     l-'i^c.  '•>  17  . 

Viiri  ill  -  •!'•  |i'r-irnliinl(iLri",  l-'t-hruarv,   I'.'iiH. 


HIGH-FREQUENCY    CUHKENTS 


A  utoconduction  Cage. — This  form  of  high-frequency  application  is 
the  typical  d'Arsonvali/ation.  The  spark-gap  is  between  the  internal 
armatures  of  the  condensers  (Fig.  348),  and  the  patient  sits  or  stands 
'e  a  large  solenoid  or  coil  of  wire,  which  is  connected  with  the  outer 
t  ures.  The  patient  is  not  in  contact  will)  any  part  of  the  a  p  pa  rat  us. 
i  utoconduction  hi/  Douhte  (1  u ill<  ////  not  Spiral*.  — (Juilleminot  's  technic 
places  the  two  spirals  so  that  they  are  parallel  and  in  the  same  direction 
(Fig.  349).  Starting  from  the  external  armature  of  one  condenser  the 
discharge  passes  to  the  external  extremity  of  one  (iuillemmot  spiral, 
then  through  fifteen  turns  of  the  latter,  then  through  a  conducting 


I'ii:.  .'vlN.-    Autoponduction  from  d'Arson- 
val's  larjrc  solenoid. 


Tip.  34!).— Gui 


cord  to  the  outer  extremity  of  the  othei1  spiral,  then  through  fifteen 
turns  of  the  latter,  and  then  through  a  conducting  cord  to  the  external 
armature  of  the  other  Leyden  jar.  It  is  important  that  the  two  spirals 
should  be  turned  in  the  same  direction.  They  are  placed  with  their 
Hat  surfaces  parallel  with  each  other  and  24  inches  apart.  With  a 
powerful  induction-coil  or  transformer  and  good  condensers  and  spark- 
irap  the  space  between  the  two  parallel  spirals  becomes  a  very  strong 
electromagnetic  field.  A  single  turn  of  wire,  hanging  freely  in  this 
space  and  parallel  with  the  external  turns  of  the  spirals,  will  be  traversed 
by  a  current  which  will  light  up  a  series  of  12-  or  20-volt  incandescent 
lamps. 

There  is  no  spark  or  effiuve  effect  from  the  inner  extremity  of  each 
spiral  with  the  connections  made  in  this  manner. 

For  treatment  the  patient's  body  should  be  so  placed  between  the 
two  spirals  that  the  long  axis  of  the  body  is  parallel  with  the  external 
turns  of  both  spirals.  The  simplest  way  i-  tor  the  patient  to  sit  with 
a  spiral  at  either  side  of  him  and  with  his  legs  raised  by  some  kind  of  a 
foot  -rest . 

Aulni'nnduction  !>//  Guillcminot  S/iirn!*  in  A/'tii'ntl  Hypertension. — 
The  treatments  last  twenty  or  thirty  minutes,  and  in  !•">  cases  reported 
by  (  lUillemuiot  l  1  he  result  of  a  course  of  t  real  im-nt s  was  to  reduce  1  he 
blood-pressure  from  about  21  cm.  of  mercury  to  about  17  cm.  Fifteen 
or  twenty  treatments  sulliced  to  produce  a  permanent  effect,  and  after 
the  first  six  treatments  any  general  symptoms,  such  as  vertigo,  debility, 
dyspnea,  chilly  feeling.-,  were  greatly  relieved. 

.  1  ulorondcnxation . --- -  \\  ires  from  two  different  turns  of  the  small 
solenoid  uniting  the  two  outer  armature-  pass,  one  to  an  electrode  held 
1  Arch.  ii 'dec! riritc  mcd.,  SrpU'iiiber  Id,  I'.MIti. 


004  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

by  the  patient  and  the  other  to  a  large  sheet  of  metal  upon  which  the 
patient  lies,  but  from  which  he  is  separated  by  an  insulating  mattress 
(Fiji.  o."iO>. 

riwfoww 


tolatietif 


Fin.  ;v>0.  -  -  Autix'uiKlcnsation. 


Fig.  .'•),"»!.      <Mnlin  resonator. 


Currents  of  High  Frequency  and  High  Tension.  Owl  in  Rt-xonator. 
—  In  this  apparatus  the  discharge  from  the  outer  armatures  of  the  two 
condenser-  passes  through  a  certain  number  of  (he  lower  turns  in  a 


•_.  :;.">_'.-     HiiMihir  rcsoiiatur  (O'l  arrcl  :n 


d  1  iv  inductoresoiianee  induces  ;i  ven 


I  her  urnier  extremity  of   the  solenoid  < 


HIGH-FREQUENCY    CURRENTS 


55") 


A  Bipolar  Omli'n  Resonator. — The  wires  from  the  external  arrnaturo.s 
of  the  condensers  are  connected  with  two  of  the  turns  near  the  middle  of 
the  helix,  and  a  high-frequency  and  high-tension  discharge  lakes  place 
from  both  extremities  of  the  helix  (Tigs.  352  and  353). 

(iiiiUcniinot'x  S/>ir<il. — The  wires  from  the  external  armatures  of  the 
condensers  are  connected,  one  with  the  outer  extremity  and  the  other 
wit  h  one  of  the  two  or  three  outer  turns  of  a  fiat  spiral.  A  high-frequency 
high-tension  discharge  takes  place  from  the  inner  extremity  of  the  spiral 
(Fi.  354). 


MEDICAL    ELECTRICITY    AND    RONTdEN     KAYS 

Iliinil   h'l  .^iir/utnr. — This  is  also  called  an  oscillator.     It  is  an  elec- 
trode handle  which  is  in  itself  a  high-frequency  resonator  (Fig.  358). 


A  good  rilluve  i-  -upplied  by  such  an  apparatus  when  connected  with 
an  induction-coil  and  condensers. 

The  portable  high-frequency  apparatus  >old  for  high-frequency  and 
/-ray  work  I-'ii:.  o.V.t  i-  usually  a  Tesla  outfit. 

Another  portable  hi»-h-fre([uency  coil  (Fig.  3o()^  is  of  such  a  si/(>  and 
/  that  n  inav  hanfr  from  anv  electric-light  socket.  It  <nve.-  a  suffi- 


'  for  the  -park  treatment   of  mole-  and  -mall  epi 


'!•    vacuum  elect  rode  1  reat  ment  of  neuraliria 


HIGH-FREQUENCY    CURRENTS 


METHODS  OF  APPLYING   HIGH-FREQUENCY  CURRENTS 

(Machado's  Table) 

f  Autocunductiun  or  inductive  application  at  a  distance 
without  resonator,  with  d'Arsonval  or  Tesla-Thom.Mm 
current  passing  through  a  law  solenoid  surrounding 
the  patient. 

f  Condenser   couch.        Schittcn- 
helm  couch. 


f  General  application. 


Autocondensation  diipo- j  PifTard's    condenser    mattre.-.- 


\\  ith  condenser. 
\\ithout  resonator.  <  \v-.i  , 

\  ithout  condenser. 


with  metal  spiral. 
Glass   condenser   electrodes 
( Friedlander  chain. 


Dim 


Electrode 

at  a  dis- 
t  a  n  c  e    <{ 
from  the 
bodv. 


.Metallic  ap- 
plicator. 


Ordinary 

- 


Sparks! 


I  Kfllimv 


Indirect 
applica- 
tion. 


I    discharge. 

[Special  for  fulguration. 
Glass  appli-  f  Vacuum  tubes.1 
cator.  {  Tubes  for  cataphore.-is. 


Electrode  applied  di- 
rectly to  the  skin. 


Electrode  sta- 
tionary. 


(  >rdinary         <  Direct  discharge, 
metallic      <  Indirect  dis- 

i       electrodes.  (      charge. 

'  Glass    vacu-  f  I:)ir(.'('r  '^charge. 
4  Indirect  dis- 

um  tubes.  , 

i      charge. 

Electrode  in  (Ordinary  metallic  electrodes. 

motion.      \  Glass  vacuum  electrodes. 
With  Pii'fard  transresonator. 
[Producing  the  high-frequency  cautery  arc. 
[Special  glass  vacuum  electrodes  applied  to  mucous  membranes. 


Without  resonator. 


f  Ordinary  metal  exciters. 

I  Containing  air. 


One  electrode  on  the     Sparks     by  !  ,  f, 

skin  and  the  other  |    means  of:  ]  Glass  tubes:     Containing  salt  solu- 

T(>sla  yacuum  tubes. 


Stat  ionarv  efHuvi 


MVIII    ant  uei    i 

over  exciter  opera-  ' 
ting  at  a  distance. 

[Rhythmical  mobile  eflluve. 
One  electrode  on  the  skin,  the  other  discharging  sparks  against  a  metal 

also  in  contact  with  the  skin  (mediate  discharge  analogous  to  static 

wave  currents). 

Both  electrodes  at  a  distance  from  the  skin  (double  effluve). 
One  metallic  electrode  applied  to  the  skin,   the  other  a  glass  vacuum 

electrode  also  applied  to  the  skin. 

Special  glass  vacuum  electrodes  applied  directly  to  the  surface. 
One  electrode  from  the  Tesla-Thomson  coil  is  applied  directly  to  the 

skin,  while  another  applies  sparks  to  a  metal  ball  held  near  another 

part  of  the  skin  (indirect  sparks  i. 
One    electrode    represented    by    PitVard'.-    t  ransre>onator    is    applied    to 

the  skin,  while   the  electrode   from    the  other  terminal   of   PifTard's 

hyperstatic  transformer  is  applied   to  another  part   of  the  skin. 


(  With  insulated  (  With  interior  metal  conductor. 

handles.  I  \Yithout   interior  metal  conductor. 

<  Insulated  throughout  their  extent,  except  the  active  part 

for  the  urethra,  rectum,  vagina,  mouth,  etc. 
Decrees  of  vacuum : 
1 /.")()()         atmosphere     -reel  vacuum. 
1/10,000     atmosphere  —  white  vacuum. 
1/100, 000  atmosphere. 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


METHODS  OF  AITLYIXC,  HIGH-FREQUENCY  (TKKKNTS  (Continued). 

Mi\(><!  method.      Autocondcnsation  ;tnd  effluve. 

With  special  apparatus  for  eloctrotlu'rmopenetrution,  transthennio, 
clectrocoatrulation  N'agelsehmidt,  Loren/..  Remind-  thermoflex. 
( laitYe.  Doven.  etc.'. 


( '.eneral  application. 


i  Undulutory  high-frequency  cur- 
i       rent   by  ctlluvc  interruption. 
I'ndulatory  high-frequency  cur- 
rent     by      an-      interruption 

pseudofaradic   . 

Local     application.-.  •[  I  "nilulatory  hitih-frcquency  cur- 
rent   by    -park    interruption 
•  called     al-o     motor-impulse 
I       current  i.- 


VACUUM   ELECTRODES   WITH  INSULATED  STEMS 

A  n' lass  vacuum  elect  rode  which  is  to  he  us<  d  in  1  he  rectum  or  mouth 
i-  often  made  with  a  doiilile  .-tern,  the  outer  one  heitui  to  protect  the  lips 
or  the  aim-  from  .-parks  when  a  hi<jh- voltage  application  is  made 


The  Author's  Special  Electrodes    and   Handle. ---The  electrodes 

u.-ed  hy  the  author,  and  perhaps  original  with  him.  have  leadinji'-in  wires 
pa-sin-^  Through  the  ii'lass  of  the  stem  and  making  contact  with  a  metallic 
Hart  ot  the  handle  into  which  thev  are  screwed,  and  hv  mean.-  ot  which 
the  current  i-  transmitted  to  them  Fin;,  ilfii'  .  See  par_e  .~>4."">j 

The  author'-  handle  '  Fisz;.  .'•> (>:•!!  i-  made  of  hard  ruhher.  insulatin«; 
all  the  metallic  portion-  from  accidental  contact  with  the  patient,  no 
matter  what  part  of  the  handle  may  t  nidi  him. 

Hie  conductin<r-cord  i-  the  flexible  in-ulated  -econdary  conduct inu'- 
''ord    u-"d    in    automobile-.      It    depend-    upon    cloth    and    re-in    or   wax 
n-tead    'it    ruhher   for    it-    iu-ulat  me;    properties.      Soft    rubber   disinte- 
grate-  m  a  few  minute-   under  the  influence  of  a  hiu'h-t en-ion  hiuh-fre- 
•  lit.      The    proper    conduct  imr-cord    can   he   touched   by  the 

tor  or   patient    without    any  -hock,  oiilv  a  -ho\\-er  of   violet    brush 
thai    from    a    condenser   electrode.       But     if    'hi-    cord    is 
:  '     hear    anv    other    cord    conductiim     hlii'h-volt  aiie    elect  ricit  V.    a 
le   the   m-ulation   and   leave  a    -pot    \\hlch    1-   Ho   longer 
lii  re  it'  the  cord   he  held   fol    a   few  seconds  a   burn   will 
•>••   ;••'••, -.'d   iron,   a    continuous  stream   ot    whit'    spark.-.      Such   a   burn 
in  ••::  i-in-j  pain  for  only  a  few  second- :  it  leaves  a  dry  port  ion 
which    come-    oh     like    a    -cab.    leaviim    a     perfectly 

Application  of  High-frequency  Current  Vacuum  Electrodes 
Through  the  Clothing.  Contrary  to  the  condition-  obtaining  when 

•      ••'    •    '.'.    iVe  of  1<  i'.'.    frequency    Upon  a  current   of  1 1  in  1 1  lVe(|Uency. 

lo  t  ho-e  nf  Sn<i\\ '-  -lat  ic  \\  a\'i   i-urri-ni  I  o  \\  hie) i  are  added 

irrent-.       I  he  "motor  impul-e  I'lirreni  "  pi-ocluce-  con- 
:      '  '  .    •  •     •    •  '    .-.    pn  iduced  | iv  the  -tat  ic  \\  ave  i-iirrent-. 


HIGH-FREQUENCY    CURRENTS 


559 


'UW.       Application  of    vacuum  electrode    by  mean-  <>t'  the   author's    completely  in-u- 


MEDICAL     KLKc   riUllTV    AND     ItUNTCJKN     UAYS 

•ralvanic  or  faradic  applications  arc  made,  high-frequency  current  and 
other  u'la.-s  vacuum  fleet  rode  applications  are  not  nuiterially  affected 
I  iy  t  he  presence  of  a  single  very  t  hin  layer  of  silk,  cotton,  linen,  or  woolen 
clothing.  Increasim:  the  thickness  of  the  material  markedly  changes 
the  charade!'  of  the  discharge.  .\  thicker  layer  of  material,  such  as  the 
u nderwear  and  t  rou.-er.-.  changes  the  character  of  t  he  a pj >\\ cat  ion  entirely. 
The  adjustment  of  apparatus  which  will  .u'ive  a  mild  discharge  without 
spark  effect,  hut  with  the  hull)  filled  with  brilliant  light  when  the  bulb 
is  directly  in  contact  with  the  skin,  shows  practically  no  luminosity 
when  applied  through  thick  clothes.  Xo  beneficial  discharge  occurs 
through  the  clothes  in  this  case.  To  obtain  luminosity  and  a  therapeu- 
tic effect  it  is  necessary  to  adjust  the  strength  of  the  primary  current, 
the  length  of  the  -park-gap,  and  the  other  factors  so  as  to  produce  a 
stronger  discharge.  There  is  a  great  deal  more  sensation  because 
of  the  -park  effect,  due  to  the  distance  between  the  electrode  and  the 
surface  of  body  and  because  of  the  stronger  currents  employed.  A 
tube  that  is  brilliantly  illuminated  produces  a  .-harp  burning  sensation 
if  applied  through  the  trousers  and  held  at  one  place  for  a  short  time. 
It  >hould  usually  be  kept  in  constant  motion,  and  then  produces  no 
undesirable  effect,  the  skin  not  being  reddened  unless  the  current  is 
applied  to  a  small  region  for  an  appreciable  length  of  time.  The  author 
ha-  never  seen  any  injury  to  the  clothing. 

The  effects  of  the  application  of  a  vacuum  electrode  through  the 
itiimie-t  underclothing  are  practically  the  same  as  if  applied  to  the 
.-kin.  There  is  the  advantage  of  modest}'  in  some  cases,  and  no  powder 
i-  required  to  enable  the  electrode  to  glide  readily  over  the  surface. 
The  therapeutic  uses  are  the  same  as  those  of  the  direct  application  to 
the  skin. 

The  effects  of  an  application  through  thick  clothing  are  actively 
counterirritanl  and  rubefacienl  if  the  electrode  is  kept  in  one  place  for 
an  appreciable  length  of  time  and  if  the  current  is  quite  a  strong  one. 
They  are  revulsive  without  rubefaction  if  the  current  is  less  powerful 
and  the  electrode  is  kept  in  constant  motion.  The  therapeutic  uses 
an-  found  in  cases  of  chronic  articular  or  muscular  or  nerve  lesions 
where  a  powerful  counterirritanl  effect  is  desired,  and  in  some  cases  of 
iicura-1  henia,  applied  alon.i;  the  spine.  The  general  indications  for 
hi^h-tensioii  hiirh-t  requency  currents  are  met  by  this  application  in 
cases  where  a  very  marked  local  effect  is  permissible. 

Physiologic  Effects  of  High-frequency  Sparks  and  Effluves. — The 
etlluve  I  ron i  a  re.-onat  or  applied  from  points  4  to  10  inches  from  t  he  sur- 
ke  a  fine  cool  or  hike-warm  bree/e.  and  t  his  produces  analgesia 
-edation.      From  a   nearer  point  there  is  a  prickling,  contraction  of 

cutaneous  muscular  fibers,  redness,  and  arterial  hyperemia.      Nearer 
there  are  powerful  muscular  contract  ions,  both  al  the  active  efH  live 
rode   and   al-o  at    the  indifferent    contact    electrode  from    the  other 
of  the  re-oiiator,  but    there  i.-   practically  no  heat   generated  in  the 
Actual  -park-  applied  in  one  place  stimulate  t  he  cutaneous  mus- 
er-   •£) u ise  fle-h  i  and   vasoconstrictors.      After  paleness,  lasting 
t'>  one  minute,  an  inten-e  cry  t  hem  a  develops.      Prolonged  appli- 
ed by  vasodilatation.  edema,  blistering,  diapedesis  of  red 
longer  hm'h-t elision  >park.-  cause  contraction  of  deep-seated 

Electrolytic  Effect  of  High-frequency  Sparks.     I  Fmh-frequency  cur- 


HIGH-FREQUENCY    CURRENTS  5()1 

rents  in  general  do  not  affect  a  solution  of  iodid  of  potash,  but  high- 
frcquency  sparks  produce  tiny  blue  points  upon  the  surface.  Xagel- 
schniidt  does  not  suppose  that  there  is  any  important  electrolytic  effect 
upon  the  tissues  from  either  the  direct  or  the  indirect  high-frequency 
spark. 

Fulguration,  or  Keating  Hart's  Method  of  High-frequency 
Sparks  for  Cancer.1  This  method  consists  in  the  application  of  Ion;; 
and  powerful  sparks  for  the  dest  met  ion  of  morbid  tissue.  The  apparat  us" 
may  be  any  of  the  resonators  giving  high-frequency  currents,  and  inav 
be  either  monopolar  or  bipolar,  the  latter  being  preferable.  The  patient 
holds  a  metallic  electrode  connected  wit  h  one  pole  of  the  resonator,  while 
the  spark  elect  rod*1  is  brought  near  the  diseased  area.  This  electrode 
has  an  insulating  sleeve,  by  which  the  length  of  the  spark  is  exactlv 
regulated,  and  a  current  of  air  or  CO.,  is  forced  through  it  to  keep  the 
temperature  from  becoming  too  high.  The  strongest  possible  discharges 
are  used. 

In  the  case  of  a  small  ulcerated  epithelioma  the  application  is 
divided  into  four  different  steps.  At  first  several  sparks  are  applied, 
producing  blanching  of  the  tissues  and  a  marked  degree  of  anesthesia, 
then  more  powerful  sparks  are  applied,  softening  the  tissues;  third,  the 
tissues  treated  by  the  sparks  are  curretted  and  enucleated;  fourth,  the 
same  powerful  sparks  are  applied  at  the  bottom  of  the  wound  to  elimi- 
nate any  traces  of  neoplasm. 

Larger  tumors, especially  those  in  which  ulceration  has  not  taken 
place,  require  the  surgical  procedure  first,  followed  by  the  high-fre- 
quency sparks  over  the  floor  of  the  wound.  The  treatment  requires  a 
general  anesthetic,  and  in  some  cases  it  is  preferable  to  destroy  different 
parts  of  a  large  tumor  at  a  number  of  different  sittings. 

A  typical  operation  by  this  method  consists  in  an  excision  of  a  can- 
cerous breast  and  axillary  glands,  under  general  anesthesia,  of  course, 
and  then  the  application  of  these  long,  loud  sparks  to  the  entire  raw 
surface,  except  the  under  surface  of  the  skin  flaps,  which  would  certainly 
become  necrotic  if  subjected  to  this  treatment.  As  each  spark  strikes 
the  exposed  muscle  a  bunch  of  muscular  fibers  may  be  seen  to  contract 
violently.  De  Keating  Hart  continues  to  apply  these  sparks  for  a 
number  of  minutes,  until  the  entire  surface1  changes  from  a  raw  red  to 
a  dry.  brownish,  cooked  appearance.  Ample  provision  is  made  for 
drainage  when  the  wound  is  closed.  The  consequence  is  a  tremendous 
oo/ing  of  serum  and  a  wound  affording  a  fruitful  field  for  infection, 
against  which  the  greatest  precautions  should  be  taken.  The  theory 
is  that  the  fulguration  has  a  tendency  to  prevent  recurrence  by  its  effect 
upon  the  remaining  tissues.  Of  course  it  cannot  prevent  .recurrences 
in  the  skin  or  along  the  cicatricial  line,  because  it  cannot  be  applied 
there. 

Having  seen  the  method  applied  by  the  brilliant  originator,  and 
con>iderinir  the  results  reported,  the  author  feel.-  that  he  cannot  recom- 
mend this  method  for  cases  of  this  character. 

The  claim  is  made  that  recurrence-;  are  very  much  less  prevalent 
after  this  method  than  after  simple  surgical  excision,  and  that  the 
cicatrices  are  as  good  cosmetically  a>  those  following  radiotherapy. 
High-frequency  sparks  seem  to  have  a  selective  effect  upon  morbid 

ctilo.  Auiiust  10.  I'.tOT. 


502 


MKDIfAL  KLi;(  TKKITY  AND  RONTGEN  KAYS 


tissue,  and  the  line  of  cleavage  between  the  tumor  and  the  surrounding 
Ik'sh  becomes  more  marked.  The  enueleation  is  easier.  The  sumo 
method  has  been  applied  lor  local  tuberculosis,  lupus  of  the  skin  and  of 
the  nose,  and  has  even  been  found  useful  in  certain  cases  oi  chronic 
.r-rav  dermal  it  i.-. 


Many  different  electrothorapeutists  employed  hitrh-frequency  sparks 

before    the    publication    of    Keating    Hart'.-    method.      The    originality 

•  latter  seems  to  lie  in  the  combination  ot  surti'erv  and  electricity. 

!  he     auihor's     electrode     (  Fi^.  ;]()())     tor     applvint:     hitrh-frequency 

for   thej'i1  de.-tnict  ive  effect    \vas   described   at    a    meeting  of  the 


'•an  [.!<•<•' ro' h'-rapeut  ic  Association  in  I'll).",  and  provides  a 
:•.'  in-  ••:  ••  .  ..  '  :  the  -tren^th  of  -parks  irom  zero  up  to  their  maxi- 
•:.  .'  !'  :.  '•.  '['hi  conduct  inn-cord  from  the  re.-onator  is  attached 

to   the   portion   of   t  hi    electrode  whii'h   i-   to   be  applied   to   the   patient. 
'1  hi-  portion  i-  -eparaie<l  1  ,\-  an  m-ulated  section  from  the  portion  which 


HIGH-FREQUENCY    CURRENTS 


503 


is  held  in  the  operator's  hand.  A  lover  actuated  by  a  spring  makes 
a  connection  between  these  two  sections  and  conducts  the  entire  dis- 
charge from  the  resonator  into  the  operator's  body.  Pressing  upon 
the  lever  introduces  a  greater  or  a  less  spark-gap  between  the  two  sec- 
tions, and  when  the  distance  is  at  its  maximum  a  powerful  spark  will 
pass  to  the  patient.  If  anesthesia  is  not  used,  as  in  the  case  of  small 
epitht'liomata  or  warts,  the  author's  technic  consists  of  at  first  releasing 
the  lever,  then  turning  on  the  current,  bringing  the  electrode  near 
the  part  to  be  treated,  and  making  an  application  of  very  small 
sparks,  which  are  increased  in  length  by  pressing  on  the  lever.  When 
a  certain  decree  of  anesthesia  has  been  produced,  the  sparks  applied 
to  the  patient  are  gradually  increased  in  length  until  the}'  are  about 
.1-inch  long.  The  whole  process  takes  but  a  few  seconds  from  the 
time  the  application  is  begun  until  all  of  the  current  is  being  applied 
as  a  series  of  sparks.  An  application  of  ten  or  fifteen  seconds  is  usually 
enough  for  the  smallest  neoplasm,  and  not  more  than  a  minute  is  re- 
quired for  those  which  are  \  m('h  or  1  inch  in  diameter.  Intense  inflam- 
matory reaction,  which  follows  the  application,  is  usually  the  active 
factor  in  the  destructive  action,  but  in  certain  case?  it  seems  desirable 
to  apply  sparks  of  special  intensity  and  for  such  a  length  of  time  as 


The  author's  method  tnves  irood 


actually  to 

results  in  both  ulcerated  and  non-ulcerated  cutaneous  epithelioma  and 

in  ulcerated  carcinoma  of  the  breast. 

Bipolar  Oudin  Resonator  Applied  for  a  Local  Effect. — Oudin 
and  Ivonneaux1  use  two  different  adjustments  for  the  application  of 
high-frequency  currents  for  local  effect.  Their  apparatus  consists  of 
a  bipolar  Oudin  resonator  connected  with  two  pairs  of  Leyden  jars, 
charged  bv  either  a  oO-cm.  induction-coil  or  by  a  closed  magnetic  circuit 
step-up  transformer  actuated  by  an  alternating  current.  One  adjust- 
ment of  the  apparatus  consists  in  connecting  the  diseased  part  with  the 
upper  extremity  of  one  resonator  while  an  eflluve  is  applied  by  a  brush 
electrode  connected  with  the  upper  extremity  of  the  other  resonator. 
The  ot  he  r  adjust  men  t  has  the  lower  extremity  of  a  single  resonator  con- 
nected with  the  diseased  area,  while  the  hru>h  electrode  is  connected 
with  the  upper  extremity  of  the  same  resonator.  An  improvement 
consists  m  placing  the  patient  upon  an  insulated  platform.  The  appli- 
cations are  made  every  two  or  three  day-.  They  last  ten  minutes,  and 
an1  followed  by  a  series  of  sparks  lasting  ten  or  fifteen  seconds. 

The  Croirn  cfflni-cr  (Tig.  'l\'->7 '  has  a  range  of  usefulness  similar  to 
t  hat  of  t  he  st  at  ic  crown. 

The    Effect    of    Condenser    Electrodes.     The>e    electrodes    consist 
of  a  metallic  or  other  good  conductor,  covered  by  glass  or  hard  rubber, 
1  Le  Radium,  September  !•"),  190,").  p.  :'>(Y2. 


o()4 


MKDK'AL    KLKCTKU'lTY    AND    KONTGEN    HAYS 


acting  as  an  insulating  dielectric  between  the  body  and  the  conductor. 
A  ii'hiss  tube,  shaped  like  a  vacuum  electrode  and  tilled  with  salt  solu- 
tion, makes  an  excellent  condenser  electrode  to  be  rubbed  over  the 
general  -urface  or  for  introduction  in  the  rectum.  Such  an  electrode 

is     applied     to     the 

(  D- — f surface  and   is  con- 

nected with  one 
pole  of  the  d  'Arson- 
val  apparatus,  while 
the  pat  ient  holds  a 
metallic  electrode  connected  with 
the  other  pole.  The  effect  is  the 
same  as  when  a  glass  vacuum  elec- 
trode is  used  with  the  same  kind  of 
current.  In  the  particular  case  de- 
scribed, and  if  the  apparatus  is  ad- 
justed for  great  amperage  and  low 
voltage,  there  will  be  little  or  no 
spark  effect,  and  the  local  effect 
will  be  ant  iphlegmasic  and  seda- 
tive, while  the  constitutional  effect 
will  be  to  lower  the  blood-pressure 
if  it  is  unnaturally  high.  There 
will  be  the  same  other  less-marked 
effects  that  are  obtained  when  a 
glass  vacuum  electrode  is  used..  In 
no  case  does  the  salt  solution  in 
the  condenser  become  luminous, 
and  with  the  current  regulated 
for  a  distinctly  d'Arsonval  effect 
there  is  only  a  little  violet  brush 
discharge  where  an  imperfect  con- 
tact is  made  wit  h  t  he  skin. 

A  salt  solution  condenser  elec- 
trode, with  a  hiiz'her  voltage  dis- 
charge, gives  the  same  shower  of 
spark-  as  the  vacuum  electrode. 
but  much  stronger  with  the  same 
conditions  in  the  rest  of  the  ap- 
parat  us. 

This  strong  application  pro- 
duce- a  powerful  revulsive  effect, 
inakim:  it  wonderfully  effective  in 
some  cases  o|  neuritis  and  mvositis. 

-oluHon    condenser   electrode   is    the    mo.- 1    perfect    means  of 
al  applications  for  obtaining  the  different    effect.-  of  the  dis- 
HT   trom    a    -tatic    machine,  <ir  trom    a    I.evden   jar  connected 
tic    machine,   or   from   either   pule  of    an    induction-coil    (the 
relish   to   lie   limited   bv  setting   the  -pint  remet  er  for  a  -hort    spark), 
•  nf  tin-  <  i  !-••!>;,  ..'e  from  a  high-frequency  apparatu.-  of  either  the  d'Ar- 
inva!  oj  t  he  <  >udin  Type. 

>  ilideli-'T  eject  rode.-  of  met  al  \\  i'  h  a  covering  oi  ha  rd  rubber  produce 
••  •-  -imilai  to  tho-e  from  .-alt  Milution  :Ja--  condenser  electrodes, 
ut  are  u-ualb  not  intended  to  be  rubbed  over  the  -urface  of  the  hodv, 


HIGH-FREQUENCY    (THKEXTS 

but  rather  for  introduction  into  the  urethra  or  nose  or  for  applications 
t;>  the  conjunctiva. 

Condenser  Electrodes  of  Large  Size. — This  is  exactly  what  the 
autocondensation  couch  or  pad  amounts  to.  Thev  are  especially  in- 
tended for  use  with  the  d 'Arsonval  or  comparatively  low-tension  high- 
frequency  currents,  and  except  in  the  case  of  sciatica  are  generallv 
used  for  the  constitutional  effects  described  in  the  section  on  Autocon- 
densation. 

OTHER  APPLICATIONS  WITH  EFFECTS   RESEMBLING  THOSE  OF  HIGH- 
FREQUENCY  CURRENTS 

Glass  Vacuum  Electrode  Connected  with  One  Pole  of  a  Tesla 
Transformer,  Known  also  as  a  High-frequency  Coil. — An  easily 
portable  outfit  no  larger  than  a  handbag  has  been  introduced  in  America 
'vthe  ISeeley  .r-ray  apparatus  and  others),  which  consists  of  a  complete 
Tesla  apparatus.  This  requires  only  to  be  connected  with  an  electric- 
light  socket  to  be  ready  for  bipolar  use  for  exciting  an  J'-ray  bulb,  or  one 
pole  only  maybe  used  to  excite- a  vacuum  electrode.  The  last  application 
is  the  subject  of  the  present  paragraph.  It  has  the  same  rather  sharp 
spark  effect  which  characterizes  the  similar  use  of  an  induction-coil,  and 
the  patient  is  liable  to  jump  if  any  metallic  object  or  another  person 
touches  him.  It  is,  therefore,  a  less  agreeable  application  than  the  one 
which  employs  a  d  'Arsonval  or  an  ( )udin  apparatus  to  excite  the  vacuum 
electrode.  A  shower  of  sparks  from  it  would  be  disagreeable.  The 
therapeutic  effects  are  similar  to  those  from  vacuum  electrodes  con- 
nected with  the  Oudin  resonator.  There  is  no  muscular  contraction 
and  scarcely  any  sensation  but  that  of  warmth.  There  is  a  stimula- 
tion of  metabolism  and  a  tendency  to  raise  arterial  tension  when  it  is 
abnormally  low.  It  has  analgesic  properties. 

Glass  Vacuum  Electrodes  and  the  Static  Machine.— The  elec- 
trodes should  have  leading-ill  wires. 

Their  effect  when  connected  with  a  high-frequency  apparatus, 
either  d 'Arsonval  or  Oudin.  actuated  by  a  static  machine,  is  about  the 
same  as  when  the  high-frequency  apparatus  is  actuated  by  an  induc- 
tion-coil. 

Their  effect  when  connected  with  one  pole  of  the  static  machine 
without  Leyden  jars  is  somewhat  different.  The  discharging  rods  of 
the  static  machine  should  be  about  .1  inch  apart. 

A  series  of  shocks  are  felt  when  the  electrode  is  held  in  the  hand. 
It  is  as  if  slight  muscular  contractions  were  being  caused,  producing 
sensations  m  the  different  tendons  in  the  wrist.  If  the  electrode  is 
hghtlv  applied  over  the  sensorv  nerves  in  the  proximal  portions  of  the 
lingers,  a  slight  tingling  sensation  is  felt  at  the  distribution  of  these 
nerves.  Rather  sharp  but  very  small  sparks  are  felt  when  the  elec- 
trode is  held  at  a  small  (list  a  nee  from  t  he  surface.  A  greater  separat  ion 
of  the  conduct  ing-rods  produces  more  marked  sensations  of  muscular 
contraction,  which  may  extend  up  as  far  as  the  elbow.  There  is.  how- 
ever, no  actual  movement  of  the  arm  and  no  rigidity.  The  person  is 
fully  charged  during  this  application,  and  any  one  touching  his  oilier 
hand,  for  instance,  receives  a  sharp  spark,  which  causes  the  hand  to 
be  'drawn  away.  The  therapeutic  effect  of  the  application  is  almost 
exactly  the  same  as  that  of  the  Morion  wave  current. 

Glass  Vacuum  Electrodes  Connected  with  a  Static  Machine 
and  Leyden  Jar.  These  give  the  same  sensations  as  the  application 


•')()(»  MKDICAL    ELECTRICITY    AND    UoXTCiKN    HAYS 

last  described,  and  the  same  physiologic  and  therapeutic  effects  as  the 
static  induced  current.  The  external  armature  of  the  Leyden  jar  con- 
nected with  one  pole  of  the  static  machine  is  grounded,  while  the  glass 
vacuum  electrode  is  connected  with  the  external  armature  ol  the  other 
Leyden  jar. 

These  two  methods  of  using  the  vacuum  electrodes  with  a  static 
machine  are  convenient  means  of  local  application  of  static  electricity. 
Their  effects  are  not  due  to  the  light  in  the  tube,  but  to  the  nature  of 
the  current  transmitted  through  the  partial  vacuum.  The  patient 

need  not  be  insulated. 

A  Glass  Vacuum  Electrode  Connected  with  One  Pole  of  an 
Induction-coil. — A  coil  suitable  for  .r-ray  purposes  may  be  used  for 
this  application.  The  vacuum  electrode  does  not  show  much  light 
until  it  is  brought  near  the  patient.  Then  quite  sharp  sparks  pass  to 
the  surface,  so  that  it  is  necessary  to  apply  the  electrode  quickly,  or  in 
some  cases,  as  in  the  rectum,  to  apply  it  before  turning  on  the  current. 
As  the  electrode  is  passed  over  the  surface  it  is  quite  essential  to  con- 
stantly maintain  a  good  contact  with  the  skin,  talcum  powder  enabling 
the  electrode  to  glide  smoothly  over  the  surface.  Kvery  part  of  the 
patient  i-  charged  with  electricity  of  such  a  kind  that  imperfect  contact 
with  any  metallic  object  or  another  person  will  give  rise  to  disagreeable 
shocks.  A  child  sitting  on  its  mother's  lap  while  this  application  is 
beinir  made  usually  cries  most  of  the  time  because  of  the  succession  of 
shocks  received  from  the  mother.  The  indue!  ion-coil  should  be  regu- 
lated to  produce  about  a  2\-inch  spark.  The  spintremeter  should  be 
set  at  ;•!  inches,  so  that  the  patient  will  be  protected  against  the  pos- 
sible occurrence  of  an  excessive  discharge.  The  application  causes 
no  muscular  contraction  and  no  sensation  except  that  of  warmth  when 
the  electrode  is  in  perfect  contact  and  a  moderate  current  is  used.  Such 
an  electrode  held  m  ihe  hand  while  an  excessive  current  is  applied,  the 
lull  power  o|  an  induction-coil,  produce.-  no  muscular  contraction  in  the 
sen-e  lit  not  being  able  to  let  go  ot  the  electrode  or  to  move  the  arm  in 
any  direction.  There  are,  however,  the  slight  tingling  sensations  in  the 
tendons  about  the  wrist  which  nio-t  strong  electric  applications  pro- 
duce. There  i-  nothing  to  be  gained  by  making  such  an  excessively 
st romr  application,  but  it  (JIM-  not  affect  the  patient  injuriously  if  done 
accji  li-nt  1  v  or  for  experiment . 

lii"    effect     ,if    a    -_dass    vacuum    electrode    connected    directly  with 

:  an  ./'-ray  induction-coil  i-  to  produce  a  local  counterirritant 

effect   wi'hout   the  necessity  for  redden  inn  the  skin,  and  a  general  effect 

in   'h'-  •'  on   nf  increasing  metabolism   and  stimulating  the  sympa- 

t  ii>-r  ic  nerves  and  glandular  activity. 

I"    i-    an    excellent    application    for   facial    neuralgia,    and    mild    cases 

'not     tie    douloureuxi    -how    improvement     after    the    first     treatment. 

I'aral;   ',<  d  in  i-cle-  sometimes   regain    then-  si/.e  and  tune  in  consequence 

•at  ion.  a-  in  cases  of  infantile  paralysis  t  real  ed  bv  the  author. 

I'  '  .  '  be  preferred  to  the  Otidin  or  d'Arsonva]  currents 

'•mini  electrodes,  and  never  for  the  application  of  a  stream 
ot  spark-,  In  '•  MI  e  i  hey  are  of  a  very  disagreeable  character. 

Hertzian  Waves.  These  are  electromagnetic  waves  propagated 
to  en  '  •  ci  - .  and  made  u-e  of  in  -ending  wireless  messages  for 

a  distance  oi  ovei  a  thou-aiid  miles.  They  a  re  liberated  bv  the  dis- 
charge oi  •  ci  imi-riii]  and  its  condenser,  and  their  commercial 
use  i-  based  upon  the  fact  tha'  thev  greatly  lessen  the  resistance  at  an 


HIGH-FREQUENCY    CURRENTS 


567 


imperfect  contact,  and  thereby  act  at  each  impulse  to  turn  on  a  stronger 
current  from  the  local  battery  which  operates  the  telegraph  receiving 
inst  rumen! . 

These  electromagnetic  waves  are  generated  in  abundance  by  r-ray 
and  high-frequency  apparatus,  and  there  is  no  doubt  that  they  produce 
therapeutic  effects. 

The  Marconi  (/•//v/f.s.s  telegraphy  .vending  and  rcct-iriny  xtation  is  shown 
in  Fig.  368.  *S.  Switch  to  connect  antenna  with  cither  sending  or  re- 
ceiving outfit.  In  sending,  every  stroke  of  the  interrupter  charges  \V 
with  a  high  electric  pressure,  which  is  relieved  by  the  spark  making 


Fiji-  308.- — Diagram  of  Marconi  wireless  telegraphy  (Houston.) 

a  temporary  path  to  the  earth.  Not  only  this  but  more  charge  rushes 
out  of  \\  than  was  put  into  it,  and  then  electricity  surges  back  again 
from  the  earth  into  \V.  A  series  of  decreasing  oscillations  take  place, 
like  a  bent  spring  coming  to  rest.  Several  million  per  second  pass 
through  wire  and  spark-gap.  The  visible  sparks  are  twenty  or  thirty 
a  second.  Hertzian  waves  are  set  up,  but  recent  work  indicates  that  they 
do  not  transmit  the  message.  Probably  the  currents  rushing  into  and 
out  of  the  earth  tend  to  charge  and  discharge  the  earth  itself  and  start 
radiating  waves  along  the  earth's  surface.  Receiving,  the  switch  is 
turned  t  he  ot  her  wav. 

('.  coherer,  two  silver  plugs  with  a  pinch  of  metallic  filings,  tube 
exhausted  and  sealed  to  prevent  oxidation. 

IV  affects  a  telegraph  relay  R  only  when  resistance  in  ('  has  been 
reduced  by  message. 

IV1  is  connected  with  the  relay  and  a  tape-printing  telegraph  receiving 
instrument  /'. 

Y\  aves  in  the  earth  encounter  vertical  wire,  ascend  it  and  influence1 
coherer,  causing  its  resistance  to  drop. 

A  buzzer  is  striking  the  coherer  all  the  time,  and  causes  the  resist- 
ance to  become  great  again  as  soon  as  the  influence  ceases. 

Marconi,  as  early  as  September,  I'.UO.  sent  wireless  messages  from 
Clifden,  Ireland,  to  Huenos  Aires.  Argentina,  a  distance  of  (1700  miles. 


•~>''>S  MKDICAI.    KI.Kt  TKKITY    AND    KoNToKN     KAYS 

THE  PHYSIOLOGIC   EFFECTS  OF  HIGH-FREQUENCY  CURRENTS 
Certain  effects  arc  common  to  all  the  different   methods  <>t  applica- 
tion, and  these  are  chieflv  those  of  increased  metabolism. 

Other  effects  depend  upon  the  mode  of  application  and  are  chiefly 
vasomotor.  Applications  in  which  currents  are  induced  in  the  human 
hodv  have  a  general  sedative  effect  upon  the  vasomotor  system  and 
reduce  blood-pressure,  while  those  application.-  which  act  more  like 
static  elect  rich  v.  by  sparks  or  eifluve,  have  a  stimulant  effect  upon  tin- 
local  circulation,  and  an  effect  upon  the  blood-pressure  which  probably 
sliii'htly  elevates  it  in  health  and  tends  to  bring  it  to  the  normal  when 
it  is  unnaturally  low  from  disease. 

Local  Effects. --If  a  metallic  electrode  is  in  good  contact  with  the 
-kin  or  mucous  membrane  and  the  high-frequency  current  is  ot  moderate 
si  remit  h  -/.  i ..  b")0  milliamperes  or  less --no  sensation  is  produced  until 
a  sense  of  warmth  gradually  develops.  This  may  change  gradually  to  de- 
cided heat  if  the  electrode  remains  in  one  place.  With  a  greater  strength 
of  current,  up  to  100,  ")()(),  or  SOO  milliamperes.  metallic  electrodes 
-till  give  no  other  sensation  than  that  of  heat.  If  there  were  an  im- 
perfect contact,  however,  brilliant  white  sparks  would  pass  from  the 
electrode  to  the  surface  of  the  body,  and  this  would  produce  a  sense  of 
pain  and  a  reflex  muscular  contraction,  drawing  the  affected  part  away 
from  the  electrode.  With  vacuum  electrodes  in  good  contact  with  the 
-kin  there  is  a  little  sensation  of  stimulation  besides  that  of  simple 
warmth.  This  is  due  to  the  very  small  sparks  which  form  an  invisible 
part  of  the  discharge,  even  with  a  moderate  current  of  100  milliam- 
peres. and  with  a  heavy  current  of  iMO  milliamperes  or  more  the 
outside  of  the  bulb  is  covered  with  -park.-  passing  to  the  surface  of 
the  body.  In  this  case  there  is  a  sensation  as  of  little  .-harp  points 
striking  the  surface.  The  high-tension  effluve  produces  a  sensation 
a-  of  a  warm  bree/e.  and  if  the  effluve  is  brought  too  near  the  surface 
rather  severe  .-parks  leap  to  the  skin  and  cause  the  usual  sensation 
produced  by  an  electric  spark,  but  do  not  cause  muscular  contractions. 
The  vacuum  electrodes,  held  at  a  little  distance  from  the  .-km,  give  rise 
to  a  shower  of  -parks  \vhich  give  only  a  sensation  of  warmth  with  very 
weak  currents,  but  with  moderately  heavy  currents  the  sparks  are 
severe  and  painful,  and  if  applied  for  any  length  of  time  in  one  place 
will  cause  blistering  or  necrosis.  Klectrodes  ot  copper  wire  covered 
with  hard  rubber  sometimes  take  the  place  of  vacuum  electrodes  inside 
'he  nose  and  elsewhere.  Thev  LMVC  rise  to  a  shower  < if  very  fine  sparks. 
and  produci  at  first  a  -liidit  sense  of  irritation.  ( 'ondenser  electrodes 
.  a  -.'.I!'-  -urrounded  bv  oil  produce  more  or  les.-  sparking,  and  this 
-  "'In  ;  hi'._'h-t  I'ei  jiiency  applications  in  the  absence  of  muscular 
con ' 

ft'ect   upon  the  skin  varies  according   to  the  strength  of 

>pli'-aT  ioi        There  may  not    be  an  v   noi  ice  able  efj'i  •<•!  or  t  here  may 

be  n  •        •     '    ,  •  •      or  1      M  roiip-  of  small   red  points 

.•    •     ih  ; ile  pm-pricks.      In -ome  ca.-es,  as  for  warts,  the  current 

c  efi'ec!       fieneralK    -peaking,  a  con.-t  it  ut  ional  effect 

al  ap]  i  hout   proi  lucing  an  v  visible 

'.:.'!:    a    pronounced    local    etfec!     is    de-ired    the    applica- 

I     udi  a  nat  un         i          n     .          une  degree  of  visi- 

l!'  I  •  v   applicat  ions   will 

'     :     t  hi  i    -ometimes.    n    i  ,,< ,    much    -pall;    effect    has   been 


HlGIL-FHIOQrKNCY    CURRENTS 

employed,  the  skin  becomes  irritated.     In  this  case  treatment  has  to  be 
suspended  for  a  time. 

The  histologie  effect  upon  the  skin  is  stimulating,  sometimes  there 
is  vasoconst fiction  followed  by  dilatation,  and  there  is  sometimes  a 
degree  of  anesthesia  produced.  Ozone  is  produced  upon  the  surface 
by  the  passage  of  electricity,  and  it  is  doubtless  absorbed  to  a  considera- 
ble extent.  There  is  a  vacuolixat ion  noted  in  microscopic  preparations 
of  the  skin  after  the  application  of  high-frequency  currents  which  may 
be  due  to  the  liberation  of  oxygen  or  ozone  in  the  tissues.  The  current 
has  a  tendency  to  promote  the  activity  of  tissue  changes,  and  this  is 
taken  advantage  of  in  the  treatment  of  chronic  inflammatory  conditions. 
It  is  always  observed  that  the  glass  electro.de  becomes  covered  with  a 
dense  dry  coating  of  secretion  from  the  surface  of  the  skin,  requiring 
the  vigorous  use  of  soap  and  water  or  even  sapolio  to  remove  it.  This 
is  due  chiefly  to  the  activity  of  the  sweat  glands  under  this  treatment. 
The  liberal  use  of  talcum  powder  enables  the  electrode  to  slide  readily 
over  the  skin  and  maintain  a  good  contact;  without  it  the  electrode 
sticks  to  the  damp  skin  and  disagreeable  sparking  results  as  the  elec- 
trode goes  from  place  to  place  by  jerks.  The  application,  if  at  all 
thorough,  is  followed  by  a  sense  of  warmth  lasting  from  a  few  minutes 
to  an  hour.  The  odor  of  ozone  or  of  nitrogen  pentoxid  may  be  de- 
tected upon  the  skin  for  hours  afterward. 

Spark  discharges  from  a  high-frequency  electrode  held  at  a  short 
distance  from  the  surface  produce1  results  similar  to  those  of  any  other 
electric  sparks.  If  severe  and  applied  to  one  spot  for  more  than  an  in- 
stant they  cause  a  painful  sensation  and  primary  anemia  followed  by 
hyperemia  of  the  skin.  A  prolonged  application  of  severe  sparks  at 
one  spot  causes  loss  of  hair  and  permanent  destruction  of  some  of  the 
hair  follicles.  Win.  L.  Clark1  has  given  the  name  desiccation  to  the  effect 
produced  by  a  stream  of  high-frequency  sparks  applied  to  one  spot  for  a 
few  seconds.  The  tissue  is  cooked  rather  than  burnt  (page  (140). 
Freund's  experiment  shows  that  such  severe  sparking  produces  an  infil- 
tration with  polynuclear  leukocytes  in  the  rete  malpighii,  extensive 
extravasation  of  blood,  and  vacuolization  in  the  intima  of  the  arterioles. 
The  inner  walls  of  the  arterioles  in  the  skin  may  be  so  much  thickened  by 
this  gaseous  infiltration  as  to  fill  the  entire  lumen.  Similar  changes  are 
produced  by  the  .r-ray,  by  the  ultraviolet  ray,  and  by  high-tension  dis- 
charges of  the  same  severity  from  static,  faradic,  or  any  other  source. 

Such  spark  discharges  from  a  high-frequency  apparatus  have  a  very 
active  bactericide  effect,  but  this  probably  is  not  the  case  with  applica- 
tions of  a  suitable  therapeutic  strength.  The  beneficial  effect  from  the 
latter  is  due  to  a  vitalizing  action  upon  the  tissue  cells  with  a  conse- 
quent greater  ivsistance  to  morbific  organisms. 

Moderate  or  severe  high-frequency  applications  to  mucous  mem- 
branes, as  about  the  mouth,  eye,  nose,  rectum,  or  vagina,  produce  effects 
similar  to  those  upon  the  skin.  Applications  of  a  therapeutic  strength 
product^  a  vitalizing  effect  upon  mucous  membranes,  not  merely  a 
transitory  hyperemia  or  stimulation  of  secretion. 

The  !)«}>(  r  Effect  of  Local  Iligfi-fre/jinncu  Application*.-  Usually 
there  is  very  little  sensation  and  no  muscular  contraction.  "U  here 
il  is  desirable  to  produce  muscular  contractions  vibratory  currents  may 
be  applied  by  connecting  the  vacuum  elect  rode- with  one  pule  of  the 


570  MF.DK  AL    KLKCTHKITY    AM)    KONTCKN    HAYS 

electrode  is  passed  rapidly  over  the  abdominal  wall,  and  if  the  current 
is  fairly  strong  a  very  pretty  play  of  muscular  contractions  is  produced. 
These  are  entirely  painless.  With  this  application  the  patient  has  a 
high-potential  charge,  and  will  receive  rather  a  disagreeable  spark  if 
another  person  or  anv  good  conductor  touches  him.  The  vacuum 
electrode  must  be  kept  in  close  contact  with  the  skin  to  prevent  disa- 
greeable sparks.  The  strength  of  the  secondary  current  from  the  .r-ray 
coil  should  be  sufficient  to  spark  across  a  H-inch  gap.  and  the  poles 
of  the  coil  should  be  placed  o  inches  apart  if  the  limbs  are  being 
treated,  or  \  inch  apart  if  the  current  is  to  be  applied  to  the  gums  or 
in  the  nose.  The  distance  between  the  poles  regulates  the  strength 
of  the  application  in  accordance  with  the  sensitiveness  of  the  part. 
The  author  has  had  especial  success  with  this  method  in  infantile 
paralysis,  constipation,  and  chronic  neuralgic  affections. 

Or.  in  another  way  of  producing  muscrlar  conn-actions,  the  d 'Ar- 
sonval  transformer  may  be  used  and  two  metal  electrodes  applied  to  the 
patient,  one  of  which  he  may  hold.  A  short  air-gap  is  made  in  the 
circuit  with  the  patient  and  powerful  painless  muscular  contractions 
are  excited  ( !•'.  F.  Strong). 

Local  applications  of  high-frequency  currents  perhaps  penetrate 
more  deeply  than  other  forms  of  electricity  which  are  propagated  to  a 
great  extent  over  the  surface  of  the  body.  The  deeper  tissues  share 
the  heat  in <:  effect  of  high-frequency  currents.  The  activity  of  lymphatic 
and  other  glands  is  increased,  and  if  the  electrode  is  in  the  rectum  the 
secretion  of  mucus  in  the  rectum  and  bladder  is  increased.  Thera- 
pcutically,  this  acts  as  an  active  stimulant  in  tuberculosis  and  other 
chronic  inflammations.  Sometimes  this  application  excites  a  move- 
ment of  the  bowels  some  hours  later.  It  always  produces  a  tonic  effect 
upon  the  entire  nervous,  vascular,  muscular,  and  .-ecretorv  structures 
of  the  bladder.  The  same  effect  is  perceptible  about  the  external  gen- 
itals and  vigorous  erections  are  produced. 

If  applied  through  the  clothes,  underclothes,  or  bandages  the  dis- 
charge from  glass  vacuum  elect rodes  has  much  more  spark  effect.  This 
sometimes  produces  decided  itching  at  the  tune  of  the  application,  but 
it  the  strength  of  the  current  has  not  been  too  great,  and  the  clothing 
has  been  quite  thin,  this  sensation  quickly  disappears.  The  current 
may  be  applied  with  nood  results  even  in  the  case  of  a  limb  all  bandaged 
[p  '.  'r  trinity  eczema.  Too  lonir  or  too  strung  an  application,  or  one 
too  loim  without  moving  the  vacuum  electrode  from  one 
nother,  or  with  too  much  -park  effect,  will  produce  redness 
ot  the  -km  which  may  be  quite  unpleasant. 

t  i</n  produces  some  superficial  ane-t  hesia  and  dimin- 

cit  abillt  V  of   nea  r-bv  muscles   a  lid  nerves.        With    the 

ffect  upon  the 

application    in 
. 
a  nco.- 

HC\   c 

ehminat  ive  or  re 

the  eft  eel  i  ,1  t  he  .r-ray  and  I  hat  of  high-frequency  current  -  upon  t  he  same 
ca>e  can  be  observeil.  The  ./--ray  ha-  an  alterative,  and  high-frequency 

CHIT'    '  '  ' 

Like   many  othei 

experimentally    kill    b 


HIGH-FRKQUKNCY    CURRENTS  571 

therapeutic   use   depends  very   little  upon  any  antibacterial   property 
they  may  possess. 

Applied  over  the  abdomen  high-frequency  currents  stimulate  gastric 
and  intestinal  peristalsis. 

Most  of  the  general  systemic  effects  may  be  produced  by  the  appli- 
cation of  vacuum  electrodes  over  a  considerable  portion  of  the  bod}',  and, 
providing  the  current  passing  through  the  vacuum  electrode  is  strong 
enough,  it  seems  to  make'  little  difference  whether  the  patient  is  holding 
a  metallic  electrode  from  the  other  pole  of  the  d'Arsonval  or  whether 
it  is  entirely  unipolar  from  the  Oudin  apparatus. 

Effect  of  Local  Applications  of  d'Arsonval  Current*. — These  may  be 
made  by  direct  metallic  contact,  as  by  metallic  electrodes,  from  the  two 
terminals  of  the  small  solenoid,  and  in  that  case  the  effects  are  the  same 
as  from  the  general  application,  with  an  additional  local  analgesic,  resol- 
vent, vasomotor,  and  trophic  effect. 

I  ndircct  application*  include  those  of  sparks  or  effluve  and  those  by 
vacuum  and  condenser  electrodes.  Their  effect  is  both  local  and  general. 
The  (jcnerul  effect  is  partly  the  same  as  that  from  general  applications, 
lowering  arterial  tension  (except  when  glass  vacuum  electrodes  are 
passed  lightly  up  and  down  the  spine  with  an  adjustment  of  apparatus 
producing  great  spark  effect)  and  stimulating  metabolism  and  similar 
effects,  but  it  has  also  an  effect  due  to  local  congestion  and  a  conse- 
quent reflex  influence  upon  every  organ  in  the  body.  It  gives  origin 
to  a  change  in  the  chemic  and  physical  state  of  the  blood  which  affects 
the  protoplasm  of  the  red  and  white  blood  cells,  whose  exchanges  become 
more  rapid,  and  to  changes  in  the  blood-plasma. 

Toxic  or  inflammatory  products  are  more  quickly  eliminated. 

The  local  effect  of  local  indirect  applications  of  d'Arsonval  currents 
is  important.  It  differs  considerably  according  to  the  method  of 
application.  A  glass  vacuum  electrode,  making  a  good  contact  with 
the  surface  of  the  skin  or  with  any  of  the  mucous  membranes,  while  a 
good  contact  is  made  with  a  metallic  electrode  from  the  other  pole  of 
the  d'Arsonval  apparatus,  produces  no  sensation  but  that  of  warmth 
if  a  current  of  moderate  strength  is  passing  through  the  patient.  150  ma. 
for  instance.  Hut  this  seems  to  have  a  cumulative  effect,  and  the 
vacuum  electrode  becomes  uncomfortably  hot  after  being  used  in  the 
rectum  for  more  than  five  minutes.  Rubbed  rapidly  over  the  surface 
with  powder  to  insure  a  good  contact,  a  much  stronger  current  may  be 
used  without  discomfort  from  heat  except  in  sensitive  regions  like  the 
face.  The  glass  becomes  quite  hot,  however,  and  fatty  material,  de- 
rived from  t  he  skin  and  mixed  wit  h  the  powder  employed,  forms  a  white 
crust  on  the  surface  of  the  glass  almost  as  hard  a-  enamel  and  requiring 
soap  and  hot  water  to  remove  it.  The  skin  becomes  somewhat  red- 
dened from  an  application  of  a  strong  current  of  200  ma.  or  more.  The 
character  of  the  application  may  be  varied  somewhat. 
of  millianiperes  may  be  increased  without  changing  the 


of  the  induction-coil.  The  voltage  mav  be  increased  independently 
of  the  amperage  by  increasing  the  length  of  the  spark-pap:  this  produces 
a  greater  spark  effect  from  the  glass  vacuum  electrode.  The  great"!' 
the  amperage  and  the  less  the  voltage  the  more  purely  d'Arsonval  is 
the  application,  and  the  greater  the  voltage,  with  a  corresponding 
reduction  in  the  amperage,  the  more  purely  Oudin  or  high-frequency 
high-tension  does  the  application  from  glass  vacuum  electrode-  become. 


•'.><_  MKDICAL    KLK<  TKHITY    AND    RON'HiKN    KAYS 

The  local  effect  of  ula-s  vacuum  electrodes  connected  with  the 
•  i  '  \rsi  inval  apparatus  and  t  he  current .  so  regulated  as  to  produce  warmth 
without  spark  effect  id'Ar.-onval  character),  is  hyperemic ;  sedative  of 
sensitive  nerves,  both  near  the  surface  and  deeper  seated;  antiphleg- 
masic  in  all  kinds  of  inflammation,  acute  or  chronic,  simple  or  infective; 
and  trophic,  -i  imulat  im:  the  tissue-  cells  to  healthy  activity  and 
develi  ipnn-nt . 

The  local  effect  of  id  ass  vacuum  e'ect  rodes.  connected  with  the  d  'Ar- 
sonval  apparatus  with  the  current  adjusted  so  as  to  aive  the  greatest 
spark  effect  and  verv  little  amperage,  is  the  same  as  if  it  were  connected 
with  the  Oudin  resonator,  but  it  will  be  described  here  for  convenience. 
A  small  vacuum  electrode.  {-  inch  in  diameter,  held  near  one  spot  for 
a  few  seconds  applies  a  shower  of  fine  sparks,  which  anesthetizes  the 
skin  to  such  an  extent  that  a  more  severe  application  does  not  cause 
pain,  and  even  slight  operations  could  be  performed.  Holding  the  glass 
electrode  close  to  the  skin  or  in  contact  with  it  the  sparks  are  more 
severe,  and  presently  the  skin  turns  white,  and  a  few  minutes  later  a 
/.line  of  intense  redness  forms  around  the  white  area.  It  takes  only  a 
minute's  application  at  the  same  spot  with  the  strongest  discharge  to 
cause  local  -uperficial  destruction.  The  subsequent  course  is  for  a  sort 
i  if  pus  blister  to  form,  looking  like  a  vaccination  pust  ule.  This  gradually 
••hanires  to  a  dry  scab,  which  leaves  no  scar  if  the  application  has  been 
comparatively  mild,  as  for  treating  a  wart,  or  quite  a  distinct  scar  if  it 
tia-  been  severe,  as  for  the  destruction  of  an  epithelioma.  A  larger 
vacuum  electrode,  which  may  be  applied  to  a  surface  1  or  '2  inches  in 
diameter,  mav  he  passed  quickly  over  the  surface  without  making 
very  close  contact,  and  produces  with  this  high-tension  discharge 
hyprrcmia  of  the  surface  and  a  countcrirrit  ant  effect,  and  an  effect 
upon  painful  nerves  which  may  not  be  desirable  in  certain  cases:  it 
seems  to  "key  them  up."  The  skin  may  even  be  made  somewhat 
red  and  rouirh  by  too  frequently  repeated  applications  with  too  -real 
a  -park  effect.  The  application  is  a  powerful  resolvent  and  antiphleg- 
ina-ic  and  usually  relieves  pain. 

Tin  /•_'//"<  r/  nf  tin'  V  in/it  /i/i<l  Cllrarin/it  /{ttdiu/inrix  frinn  the  (ilaxK 
i  •  .  ••  h  '  '  >"/'.*•.  \isible  Im'ht  is  produced  by  the  pa-sa.ire  of  a  cur- 
rent ot  elect  1'icit  v  through  a  tube  exhausted  to  about  ,,-,',,,,  atmosphere. 
I'.'i'  fo'oi  Varies  \villi  the  exact  decree  of  vacuum.  Some  ot  these  lubes 
are  tilli-d  with  a  beautiful  blue,  lilac,  or  violet  color,  and  in  some 
there  are  -  ,  patches  of  the  apple-green  color  which  indicates  the 
pfe-'-nce  ot  an  appreciable  amount  of  .r-rav.  The  visible  li^ht  from 
one  ot  the  va<-  nun  electrodes  ha-  no  demonstrable  physiologic  or 

if  the  current  t  hr<  'U^h  the  part  ial  vacuum,  and  especially 
between    different    parts   nf   the    lube   and    the    patient 
mav   be   seen    passim:1  alomj    'lie  outside  of  the   tube 

•  •••'  '    ,\    ill    the    i';:4!'  tit    .   produci  -    nltrnriuli  t  rnilid- 
.    e    (luori  iscence    111    a     piece    o|     \\lllemite    held    near 

•  •;   room       The  ultraviolet    ray    thus    produced  has  its 
!  H  rating  o/one  from   the  atmosphere,  and  of  being 
-uperiicjal   !..  ;.••-'  M    i  he  -kin.      1 1    i.-  ha  nil  v  to  be 
;  vi'  ill  •!     ra  v  -     ab-orbed     I  r.      t  he     hoi  iv    during    a 
o!    VaciiUI       •          '         :    -    t  a  I-.'  •.-    all Y    more    <  lirect    ]  >al't 

It  1C   efject  . 

•  i  i  hv  tin   application  of  t  he  vacuum  elect  rode-  and 


HIGH-FREQUENCY    CUHUKNTS  o/i? 

ultraviolet  radiations  i>  very  important.  Rubbing  the  vacuum  electrode 
over  perhaps  a  four!  h  of  t  he  surface  of  the  body  for  ten  or  t  we]  ve  minut  es 
bathes  the  patient  in  o/one  gas  for  that  length  of  time.  It  is  absorbed 
by  the  body  just  as  carbonic  acid  gas  is  absorbed  from  bathing  in  water 
charged  with  that  gas.  Its  general  effect  is  that  of  o/one  inhalations, 
increased  processes  of  oxidation  in  the  blood  and  every  other  tissue. 
Nitrogenous  substances  are  completely  oxidized  and  leave  the  system 
as  urea  instead  of  being  incompletely  oxidi/ed  to  form  uric  acid,  some 
of  which  would  be  eliminated,  but  some  of  which  would  form  an  irritant 
deposit  in  the  joints  or  nerves.  The  odor  which  is  noticed  upon  the 
patient,  and  which  may  even  cling  to  his  clothes  for  several  hours,  is 
chiefly  that  of  nitrous  acid  produced  at  the  same  time  as  the  o/one. 
This  acid  may  play  some  part  in  the  effect  produced  by  the  applica- 
tion. Yacuoles  or  cavities  filled  with  o/one  may  be  found  in  the  tissues 
directly  subjected  to  this  treatment. 

In  addition  to  the  effects  described  the  glass  vacuum-electrode 
application  has  other  effects  which  are  dependent  upon  the  nature  of 
the  currents  which  it  transmits.  These  maybe  either  those  of  the  low- 
tension  high-frequency  type,  called  d'Arsonval  currents,  or  the  high- 
tension  high-frequency  currents,  of  which  the  Oudin  resonator  yields 
an  excellent  example,  or  the  current  from  a  static  machine,  or  the  cur- 
rent produced  by  one  pole  of  a  Tesla  coil.  These  are  the  types  of 
current  which  are  most  often  applied  by  means  of  the  vacuum  elec- 
trodes, and  they  have  quite  different  effects,  especially  upon  the  general 
system. 

Systemic  Effects  of  High-frequency  Currents.  Experiments 
.^hotrint/  th<  Ejl'ci-t  of  High-frequency  Currents  on  Aninmlx. — D'Arson- 
val's  experiments1  showed  in  a  general  way  that  high-frequency  cur- 
rents caused  the  blood-vessels  in  a  rabbit's  ear  to  dilate  at  first  and 
then  to  contract  and  remain  so.  also  that  the  general  blood-pressure 
was  first  reduced  and  then  increased. 

Carvallo-  found  no  effect  from  the  autoconduction  cage,  but  that 
there  was  an  effect  from  the  application  of  the  currents  directly  to  the 
skin.  Strong  currents  cause  sensation  and  a  motor  reaction  and  a  fall 
in  blood-pressure. 

Boedeker  used  the  apparatus  already  described  as  the  German  ar- 
rangement. He  found  no  effect  from  the  autoconduction  cage,  but  a 
decided  effect  from  a  direct  application  to  the  skin,  a  primary  phase  of 
vasomotor  contraction  and  increased  blood-pressure. 

According  to  Doumer,:!  of  Lille,  France,  the  effect  of  high-frequency 
currents  on  the  cells  is  the  fundamental  one.  and  this  can  be  demon- 
strated on  vegetable  as  well  as  animal  cells. 

O//.xv  mil  in/is  ['/K»I  tin  Ejjtct  of  High-frcqucnci/  ('nrn-nt*  Applied 
/.<>i-ii!li/  in  Mnn.  [) 'Arsonval's  observation,  that  after  a  long  or  strong 
enouu'h  application  the  skin  becomes  reddened  locally  and  local  and 
sjj-neral  perspiration  sets  in.  is  a  matter  of  daily  observation  by  the 
aut  hoi1  when  using  vacuum  elect  rodes  con  nee  ted  with  the  Oud 
tor.  D'Arsonval  finds  that  a  change  in  arterial  pressure  is 
n  diseases,  such  as  diabetes,  from  ; 


dVWl    Midi..  |S!i7.  i1 
-('.    \\.    XIII.    Internal     Me. 
Physiology,  p.   I '20. 

'  :i  I..-  Itailiuin.  Sept.   1.",.   1 '.(()."). 


574  MKDICAL    KLKCTKICITY    AM)    KONTllKX    RAYS 

held  in  the  hands  and  connected  with  the  small  solenoid.  Some  patients 
show  a  material  fall  and  others  a  material  rise  in  blood-pressure. 

Moutier  found  that  sparks  from  an  Oudin  resonator  applied  along 
the  >pme  produced  a  very  rapid  rise  in  blood-pressure,  amounting  to 
1.  ^.  ti.  7.  or  even  s  cm.  of  mercury.  These  and  static  sparks  along  the 
spine  are  the  best  methods  of  treatment  for  neurasthenia  with  hypo- 
tension. 

Doumer  and  <  hulin  find  that  high-frequency  high-tension  sparks 
turn  the  skin  white,  and  that  this  is  succeeded  by  an  erythematous 
blush  which  may  last  for  hours.  The  aut  hor  has  observed  this  especially 
in  cases  where  high-frequency  and  high-potential  sparks  are  applied 
from  a  metallic  electrode,  as  for  the  destruction  of  epithelioma,  but 
in  these  cases  there  is  apt  to  be  a  central  pure  white  area  where  the 
sparks  have  been  applied,  surrounded  by  a  /one  of  intense  redness. 

According  to  Oudin 's  observations,  an  implication  of  the  high-fre- 
quency high-tension  ehMuve  to  any  portion  of  the  body  produces  an 
almost  instantaneous  vasomotor  spasm  which  suppresses  the  capillary 
pulse  in  the  hand.  \Yhen  the  application  is  stopped  the  capillary 
pulse  gradually  regains  its  original  amplitude  through  a  series  of  oscil- 
lations. 

The  monopolar  effluve  of  high-frequency  currents  increases  arterial 
tension1. 

THE  EFFECT  OF  GENERAL  APPLICATIONS  OF  HIGH-FREQUENCY  CURRENTS 

Effects  of  General  d'Arsonvalization.  —  A  current  of  (i(K)  to  1000 
ma.  from  direct  metallic  contact  or  by  induction  t  ra  verses  t  he  body,  often 
without  any  sensation  and  always  without  pain.  Kqually  strong  cur- 
rent- from  vacuum  electrodes  or  spark  electrodes  or  eflluvers.  or  from 
condenser  electrodes  or  autocondensat  ion  pads  or  couches  acting  as 
such,  mav  give  rise  to  sparks  which  are  anesthetizing  or  painful  or 
cauteri/ing  or  destructive,  according  to  their  si/e  and  the  length  of 
time  during  which  they  are  applied  to  one  spot.  There  is  a  sensation 
<>f  warmth  in  the  hands  from  holding  the  metal  electrodes  in  autocon- 
•  lensat  ion. 

There  are  increased  tissue  ch  an  ires,  more  rapid  oxidation,  more 
rapid  reduction  of  the  oxyheinoglobiii  in  the  blood,  increased  elimina- 
tion of  waste  products  in  the  urine.  The  effect  is  due  to  an  action 
upon  the  Lire  at  sympathetic  nerves  controlling  vasonmtor,  secretorv, 
t  henm  >ireiii  t  ic.  and  peristaltic  functions.  The  general  applications 
have  little  or  no  effect  upon  the  central  nervous  -vstem  controlling 
-ensation  and  voluntary  movement.  It  has  special  effects  upon  the 
protoplasm  of  tissue-cells  everywhere,  increasing  the  rapiditv  of  their 
natural  fliemic  changes,  and  special  effects  on  bacteria  and  ferments 
and  animal  poisons. 

I  hen-  i-  a  soot h ing  effect  upon  any  painful  condit ion.  and  sometimes 
this  mav  be  accompanied  bv  slight  drowsiness.  Sometimes,  however. 
t  hen  i-  a  -en  -e  i  ,f  e  \lnl  a  rat  ion.  and  one  pat  lent  ot  the  aut  hor's  felt  like 
ualkiiiL1  all  the  \\ay  home  (twentv  mile.-)  alter  each  treatment.  More 
often,  however,  there  i.-  no  immediate  chantre  in  the  uav  the  patient 


t  on  the  blood-pressure  is  ot  great  importance,  and  like 
of  electricity,  high-frequency  currents  ad  as  regulator,-  of 
•  '  producing  a  marked  effect  upon  a  healthy  person. 

!  \llicrt   \\  i  ill,  l.i-  Uaclimn.  Sept.   \.~>.   r.tn:.,  p.  :;i)j. 


HKill-FREQI'ENCY    CURRENTS  575 

The  same  is  true  of  the  effect  of  digitalis  upon  the  blood-pressure,  accord- 
ing to  the  observat  ions  of  0/yhlarg.1  He  found  that  when  an  infusion  of 
digitalis  is  given  to  individuals  with  normal  circulatory  apparatus  in 
quantities  equal  to  that  administered  to  persons  with  valvular  disease, 
there  is  no  increase  in  the  blood-pressure  or  in  the  amount  of  urine 
excreted.  In  cases  of  rheumatism,  gout,  asthma,  and  kidney  disease, 
and  in  neurasthenia  with  high  arterial  tension  the  application  of  high- 
frequency  currents  causes  a  reduction  of  the  blood-pressure.  The 
autoconduction  cage  has  been  found  more  effective  in  this  way  than 
the  autocondensation  couch  or  the  application  by  vacuum  electrodes, 
but  any  method  will  produce  the  desired  effect.  This  reduction  is 
progressive  from  one  treatment  to  another  and  occurs  even  in  cases  of 
arteriosclerosis,  for  which  high-frequency  currents  are  an  excellent 
treatment.  The  observations  of  Moutier  and  Challamel-  show  that 
a  reduction  of  5  to  i)  centimeters  of  mercurial  pressure  takes  place  after 
the  first  treatment  with  the  cage  in  cases  of  high  art  ('rial  tension.  Five 
centimeters  is  the  maximum  reduction  from  a  single  treatment  with 
the  couch. 

In  cases  of  defective  metabolism  we  find  increased  oxidation  produced 
by  high-frequency  currents.  In  gout  and  rheumatism  the  urine  con- 
tains an  increased  amount  of  urea,  while  the  uric  acid  disappears.  In 
other  words,  the  nitrogenous  matter  becomes  more  completely  oxidi/ed 
in  the  system.  And  this  effect  is  not  a  temporary,  but  a  permanent 
one  of  increased  tissue  activity.  The  energy  is  so  great  that  it  produces 
a  tonic  effect  upon  any  person  within  10  feet  of  the  apparatus.  The 
present  author  enjoyed  extraordinarily  vigorous  health  during  the  four 
or  five  years  following  the  introduction  of  these  currents,  in  spite  of 
the  fact  that  the  nature  of  the  work  confined  him  to  the  office  practi- 
cally all  day.  winter  and  summer. 

The  oxygen-carrying  capacity  of  the  hemoglobin  of  the  blood  is 
increased  as  well  as  the  amount  of  hemoglobin.  The  human  output 
of  carbon  dioxid  is  sometimes  increased  from  17  to  .'->7  liters  per  hour, 
and  there  may  be  an  increase  in  heat  production  from  70  to  127  calories 
per  hour.  The  bodily  temperature  docs  not  vary  more  than  a  small 
fraction  of  a  centigrade  degree  (d '. \rsonval ). 

The  amount  of  phosphoric  acid  in  the  urine  is  increased.  The 
toxicity  of  the  urine  is  increased.  There  is  an  increased  elimination 
of  CO,.' 

The  application  is  apparently  innocuous,  and  there  are  no  special 
contraindications,  except  that  perhaps  it  is  less  likely  to  be  of  benefit  in 
acute  inflammatory  conditions  than  elsewhere.  And  it  is  but  fair  to 
i-tate  the  belief  of  some  observers  that  it  is  likely  to  precipitate  an 
acute  attack  of  gout,  though  this  appears  very  doubtful.  The  author 
lias  used  it  successfully  in  the  treatment  of  acute  attacks. 

Sometimes  an  increase  of  arterial  tension  will  be  noticed  in  a  healthy 
person  in  consequence  of  the  application. 

High-frequency  currents  produce  a  reduction  in  weight  on  account  of 
the  increased  oxidation.  This  is  most  noticeable  in  cases  of  obesity. 

The  Thermal  Effect  of  High-frequency  Currents. — Somerville; 
has  especially  called  attention  to  the  increase1  in  surface1  temperature 
and  also  in  the  temperature  in  the  mouth  which  occurs  during  the  appli- 

1  Wiener  klinischo  Rundsthau,  April  !.">,  1000. 
-  Academic  dcs  Sciences.  Paris,  Feb.  i:>-23,  1905. 
3  Medical  Kleetrolo^y  and  Radiology,  -May,  19(K5. 


")/()  MKniCAI.    ELECTRICITY    AND    KONTdKN    RAYS 

cation  of  high-frequency  currents.  This  increase  amounts  to  from 
\  to  1°  F.,  and  has  been  verified  by  Lacomte,  Benoist,  d'Arsonval, 
\\Vrtheim  Salomonson,  and  others.  F.  De  Kraft1  (motes  Sommerville'-' 
in  regard  to  the  rise  of  surface  temperature  from  high-frequency  cur- 
rents. The  autocondensation  couch  from  one  end  of  the  solenoid  and 
the  handle  from  the  other  end  of  the  solenoid  and  2~>()  ma.  cause  1.}°  to 
t'r  F.  rise,  especially  of  the  flexor  surface  above  that  wrist;  tiOO  ma.  in 
one  case  raised  t  he  surface  temperature'  as  much  as  14°  F..  but  the  patient 
could  not  stand  the  .-welling  of  the  arm  bandaged  with  the  thermometer 
more  than  twelve  minutes.  Under  the  tongue  the  temperature  rose  only 
1  or  2  degrees.  Various  explanations  are  offered.  Somerville  says, 
"This  ri<e  of  temperature  is  undoubtedly  due  to  the  action  of  high- 
frequencv  currents  on  the  vasomotor  system,  which  under  the  in- 
fluence' of  the-  current  permits  of  increased  peripheral  circulation." 

'There  is  a  dilatation  of  the1  deeper  vessels  also.  This  undoubtedly 
explains  why  the  sphygmometer  pressure  is  lowered.  Somerville 
-hows  also  that  the  emission  of  heat  from  the  body  is  increased.  There 
is  probably  an  increased  production  of  heat,  and  this  is  accounted  for 
by  Salomonson  on  a  purely  physical  basis. 

These  high-frequency  currents  of  high  voltage  and  amperage 
'•an  heat  the  filaments  of  electric  lamps  through  which  they  pass  to 
incandescence,  and  it  is  evident  that  they  produce  a  certain  thermic 
effect  in  passing  through  a  conductor  as  resistant  as  the  human  body. 
\\Vrtheim  Salomonson  regards  this  as  offering  a  sufficient  explanation 
of  the  rise  of  temperature  which  is  observed. 

He  think-  that  the  diminution  of  arterial  ten-ion  and  a  part  of  the 
general  curative  effects  of  high-frequency  currents  depends  upon  this 
production  of  heat  in  the  body  either  locally  or  generally.  These 
observations  apply  to  bipolar  applications  from  electrodes  directly  in 
contact  with  the  body,  to  the  condenser  couch,  and  to  monopolar  appli- 
cations  with  the  Oudin  resonator.  He  does  not  think  that  they  apply 
to  the  action  of  the  effiuve  or  of  the  condenser  electrode. 

Observations  Upon  the  Effect  of  High-frequency  Currents  in 
Patients  with  High  Arterial  Tension.-- The  apparatus  used  in  many 
M]  Motitier's  cases  was  a  '.t-incli  induct  ion-coil  with  a  mechanic  in- 
terrupter,  a  <  iaiffe  plate  condenser  with  petroleum  oil  insulation,  and 
an  auioconduct  ion  cage.  At  the  first  treatment  the  blood-pressure  was 
lowered  :;.  ).  .">,  t;.  ()r  even  !)  cm.  of  mercurv.  and  in  a  few  treatments 
the  blond-pressure  was  alwa\>  reduced  to  normal,  about  b">  cm.,  when' 
it  would  remain  for  several  weeks. 

has    toiuid    that    the    pressure    mav    even    be    reduced    to 


the  same  beneficial  result-  from  the  use'  of  the 
ion  cage  in  cases  of  neurasthenia  with  high  arterial  tension, 
iidon  m  .1  rases  not  subjected  to  any  dietary  regimen;  Doumer 
^I''-  -  'ase  nt  Parkinson's  disease  and  I.e^-endre  in 

• '  1 1  •  •  -  ] :  i .    all' 
' 

1     a  1 1 1 

(      ,,      T      ,       .        . 

on.    v 

V      •      .|,,ur. 
\n'li.  '.;   I,1'. nt 


(TKHKXTS 


577 


of    mercury.      This    increased    blood-pressure    disappears    after    about 
twelve  minutes. 

The  difference  in  the  results  may  be  due  to  difference  in  the  appara- 
tus, as  explained  on  p.  f>o2. 

Furthcf  Detdila  «J  the  Application  of  Hiyh-frequencij  Current*  in 
!!///nrt<  nxton.  --Short  t  real  inents  of  not  more  than  five  or  ten  minute- 
are  best ,  and  should  be  given  two  or  I  hree  times  a  week. 

Diuretics  and  laxatives  are  desirable  to  avoid  the  effect  of  increased 
metabolism  at  the  beginning  of  the  course  of  treatment. 

Apo.stoli  found  that  the  autoconduetion  cage  is  contramdicated  for 
certain  classes  of  diseases-  hysteric  anemia,  debility,  senile  rheumat  ism, 
and  certain  cases  of  diabetes,  anemia,  and  chloro-anemia.  Some  of  1  liese 
patients  experience  nausea  or  vertigo  and  depression. 

Denoyes  found  thai  many  patients  with  different  diseases  experi- 
ence no  sensation,  while  others  notice  a  prickling  sensation  or  that  the 
face  feels  hot,  and  others  feel  a  little  vertigo  or  sense  of  slight  intoxica- 
tion aft  er  the  t  reat  ment . 

Moutier  notices  that  patients  \viih  low  arterial  tension  feel  badly 
if  treated  by  the  autoconduct  ion  ca,u'e.  and  consequently  patients  \\ith 
lithiasis  ami  hypotension  requiring  high-frequency  treatment  should 
receive  this  in  the  form  of  sparks  applied  along  the  spine.  This  tends 
to  raise  tin'  blood-pressure. 

Patients  with  hypertension  treated  by  the  autoconduct  ion  cage 
sometimes  notice  slight  formication,  sometimes  a  decided  feeling  of 
well-being,  but  generally  no  sensation  at  all. 

The  pulse  rate  is  but  slightly  affected. 

The  enlarged   heart    in   old   cases  of  hypertension   becomes   smaller. 

Cases  in  the  hospital  and  on  a  strict  diet  of  bread  and  milk  often 
have  a  normal  arterial  tension  after  three  treatments  in  the  autocon- 
ductmn  cage.  The  rapidity  of  the  results  i>  usually  proportional,  not 
to  the  severity  or  the  duration  of  the  disease,  but  to  the  hygiene  of 
the  patients.  The  results  are  equally  good  in  cases  where  a  strict  diet 
without  high-frequency  treatment  has  proved  unavailing. 

Experiments  have  been   reported  by  ,)osm'.    Loeper.   and  Josserand 
upon   animals  whose  arteries   have   been  made   atheromatous  by  long- 
continued   high  arterial   tension   from   repeated   injections  of  adrenalin. 
High    arterial    tension    seems    to    be    the 
cause  of  the  arteriosclerosis  which  follows. 

Aiitocoiiduetion  of  high-frequency  cur- 
rents affords  the  best  means  of  treating 
arteriosclerosis  by  removing  its  cause, 
high  arterial  tension. 

hlfcftnj  .  \  />/>/ icfil inns  tit  j f  n/h-f  /'<  </ii(  it <•  1 1 

Current*   <n    Artirxil   Hypertension.     The 

author's  customary  method  is  by  the 
use  of  an  autocondensat  ion  pad  (  I-'iu\ 
o(i')").  The  spark-gap  is  between  the  inner 
armatures  of  the  two  condensers,  which 
are  also  connected  with  the  secondary 
terminals  of  a  12-inch  induction-coil.  A 
small  solenoid  connects  the  outer  armatures,  and  from  two  turn 


~)7S  MKDH'AL    ELECTRICITY    AND    KONTGEN    RAYS 

meter  shows  the  strength  of  the  current  in  one  of  the  wires  leading  to 
this  pad  to  !>»•  perhaps  TOO  ma.  when  the  patient  is  seated  upon  the  pud, 
and  onlv  100  ma.  when  lie  is  not.  This  would  apparently  indicate 
that  ('»()((  ma.  of  high-frequency  current  traverses  the  patient  's  body. 

The  treatments  hot  live  or  ten  minutes.  They  have  not  in  the 
author's  cases  been  followed  by  the  very  marked  fall  in  blood-pressure 
reported  bv  Mouiier  from  the  autoconduct  ion  cage.  but  by  a  more 
gradual  improvement  in  consequence  oi  a  course  oi  treatments.  Pat  lent  s 
with  arteriosclerosis  resulting  even  in  hemianopsia  and  other  apoplectic 
effects  have  been  restored  to  apparent  health. 

Delherm  and  Laquerriere,1  after  considerable  experience  with  the 
effects  of  the  uutocondeusution  couch  and  the  autoconduct  ion  cage, 
and  following  as  closely  as  possible  the  technic  employed  by  Moutier, 
have  come  to  the  following  conclusions:  ill  That  the  immediate  re- 
duction in  blood-pressure  is  not  us  constant  or  us  marked  as  others  have 
observed  it  to  be.  I'Ji  The  permanent  reduction  is  decidedly  less 
marked  and  less  constant.  (3)  Kven  with  a  suitable  regimen  high- 
frequencv  currents  do  not  surely  prevent  the  bad  effect-  of  arteriosclero- 
sis. ill  There  does  not  seem  to  be  a  marked  reduction  in  capillary 
blond-pressure,  but  there  is  a  decided  increase  in  the  amplitude  of  the 
capillary  pulse.  (•'))  The  best  clinical  results  in  high  arterial  tension 
are  apparent  in  patients  who  can  be  classed  under  the  general  heading 
of  congestion  (arthritic,  gouty,  urteriosclerotic.  etc.).  I('M  Benefit  does 
not  alone  depend  upon  an  effect  on  the  blood-pre.-sure.  but  perhaps 
more  upon  an  effect  on  general  nutrition  and  the  urinary  elimination. 
The  modification  in  the  capillary  pulse  produces  a  better  aeration  in  the 
luni;-.  a  more  marked  elimination  ot  carbonic  acid,  and  a  more  active 
fixation  of  oxygen  bv  the  blood.  This  increases  the  rapidity  of  the 
exchanges  and  the  activity  of  thermogenesis.  Toxins  are  more  com- 
pletely eliminated. 

Doumer's  Results  with  a  Measured  Electromagnetic  Field  in  the 
Autoconduction  Cage.  Believing  that  differences  in  clinical  results 
may  follow  differences  in  the  strength  ot  the  field  in  which  the  patient 
i-  placed,  he  regulates  his  apparat  us  so  as  to  produce  in  every  case  a  field 
of  .")()().()()()  (lauss.  (Moutier  's  field  averages  loo.ixii)  (iaiiss.)  The 
meter  lor  thi-  observation  is  placed  in  view  inside  the  aut  oconduct  ion 
<•;;_'.  Tli'-  necessity  for  such  a  meter  lie-  in  the  fact  that  the  strength 
of  the  held  varies  with  different  apparatus,  and  even  with  the  same 
'  i.~  .:  ':.'•  interrupter  nr  the  -park-Map  acts  a  little  differently. 
lie  uses  ;i  |J-inch  induct  inn-coil  as  the  source  ol  his  power  and  plate 

collden-ef.-     1H|  llHTSei  1     HI    oil. 

AH    tour    patients    reported    upon-    -howed    a    steady    improvement 


''  1  v  to  I  '.'>..  i.  ]  i  >.  1  7.7").  and  1  ti  mm.       1  he  t  real  men  t  last  ed  ten 

in  i  from  three  to  iitteen  treatments  were  required. 

.'•  M  •    remained  normal  alter  the  treatment-^  were  di.-con- 

'  '•       pa'ieni    had  a  lar^e  hydrocele,   which  disappeared  (luring 
cour-e  oi    •  ;  i  a  t  meiit    without    an  v  direct   apphcat  ions  or  local  t  n-ai  - 
n)    ii 

-  have  found  that    the  same  current-  applied  in  cases 
i-e    the    arterial    ten-ion,    but    the    higher    tension 
>:a  '  he  '  >•  idm  resonator  are  more  effect  ive  in  this  direction. 

,|'i:i,  firicit.'  \1.  -1  .  July  10,   l'.'<)7. 
:      July  ;_'.">,    I'.'Oi).  [..  .")  .")(',. 


HKiH-FKI-XjrK.NCY     CUKKKNTS  579 

The  effect  upon  the  blood-pressure  is  not  due  to  a  depressing  effect 
upon  the  heurt.  Thi'  d'Arsonva!  applications  relieve  the  heart  from 
the  strain  encountered  in  driving  blood  through  the  contracted  arterioles 
and  capillaries,  and  the  Oudin  applications  have  a  tonic  effect  upon 
the  heart  as  well  as  upon  the  vasomotor  system. 

Effect  of  High-frequency  Currents  in  Diabetes. — D'Arsonval 
and  C'harrin,  Boinot  and  Poncy,1  Apostoli  and  Berlio/,  Reale  and 
Ren/i,  and  \  inus  have  treated  numerous  cases  of  diabetes  by  approxi- 
mately the  technic  to  be  described.  The  secondary  terminals  of  an 
induction-coil  are  connected  with  the  internal  armatures  of  two  conden- 
sers and  the  spark-gap  is  between  the  latter.  The  outer  armatures  are 
connected  by  a  small  solenoid,  from  two  turns  of  which  wires  lead,  one 
to  a  metal  electrode  held  in  the  patient's  hand  and  the  other  to  a  foot- 
plate or  foot-bath  making  contact  with  the  patient's  foot  (Fig.  370). 

Every  one  of  the  authors  cited  report 
uniformly  beneficial  effects  upon  the 
patient's  general  condition,  whether  tin; 
sugar  disappears  from  the  urine  or  not. 
In  most  cases  the  sugar  was  markedly  re- 
duced in  amount  and  in  several  cases  it 
entirely  disappeared.  The  treatments 
usually  lasted  ten  minutes,  and  were  given 
every  day  for  ten  or  twenty  days. 

Autoconduction    cage    treatment    did  

not  lead  to  a  disappearance  of  the  sugar  Fig.  1570.—  D'Arsom-a!  hiph-f re- 
in four  cases  reported  bv  Yinaj  and  queney  currents  applied  by  two 
•, --•  "  J  electrodes  for  diabetes. 

\  lette. 

Colin  also  finds  that  high-frequency  applications  do  not  modify 
the  amount  of  sugar. 

Boedeker,  using  an  apparatus  with  the  spark-gap  between  the 
external  armatures,  the  (ierman  method  (Fig.  34(i.  p.  oo2).  found  that 
high-frequency  current >  did  not  change  the  amount  of  sugar,  but  did 
very  markedly  improve  the  general  health.  In  one  case  of  diabetes 
there  was  marked  acetonuria.  which  completely  disappeared  during 
a  course  of  high-frequency  treatments,  but  returned  after  the  treat- 
ments were  stopped. 

Denoyes  has  obtained  excellent  results  as  to  general  health  in  cases 
treated  by  the  autoconduction  cage,  but  the  circumstances  of  the 
patients  as  to  diet,  etc.,  were  such  that  the  effect  upon  the  sugar  could 
not  be  determined. 

Cases  of  diabetes  treated  by  the  author  have  shown  a  reduction  in  the 
amount  of  sugar  from  2700  grains  (1M)  grams')  per  diem  to  a  mere  trace, 
and  this  has  been  associated  with  a  very  great  improvement  in  general 
health.  The  treatment  has  been  by  the  application  of  a  glass  vacuum 
electrode  over  the  abdomen,  the  current  being  a  unipolar  high-frequency 
high-tension  discharge  from  the  Oudin  resonator  (Fig.  371 ).  Applications 
of  the  .c-ray  have  been  made  over  the  region  of  the  pancreas  and  liver. 

Other  Effects  of  High-frequency  Currents. — Capillary  vasocon- 
striction  is  most  marked  when  the  high-frequency  high-tension  efiluve 
or  sparks  are  applied  to  a  part  of  the  body  symmetric  with  that  in 
which  the  capillary  pulse  is  studied. 

The  lowering  of  blood-pressure  produced  by  d'Arsonvalization  is 
es  dc  la  ^ucicte  de  luuloiru1.  July  '.>\.  1SC7. 


580 

followed  hv  a  ri.-e  uhich  lasts  for  a  considerable  time,  just  as  the  con- 
t  faction  of  thi'  capillaries  from  the  < hidin  application  i.-  succeeded  by  a 
prfiod  of  capillary  dilatation  \\ludi  may  even  be  permanent. 

Cases  in  \\liiih  hi^h-t'rcquency  hi<di-tension  applicalions,  such  as 
etilu\'iat  ion  aloni:'  the  spine,  appeal'  to  be  indicated  should  not  receive 
t  his  applicat  ion  it'  t  he  blood -pressure  is  Hi  cm.  ot'  mercury  or  higher  t  han 
this. 

High-frequency  Currents  in  the  Treatment  of  Tuberculosis.— 
Thi-  subject  i>  partly  considered  in  the  paragraph  on  Pulmonary 
Tuberculosis  i  p.  (,07),  The  technic  for  such  cases  is  iriven  in  detail 
there.  The  beneficial  effect  in  p-neral  or  local  tuberculosis  seems  to  be 
due.  not  to  ;mv  dii'ect  effect  upon  the  bacilli,  but  to  a  tonic  effect  upon 
the  tissue  cells  and  upon  ail  processes  of  metabolism.  The  results  ot 


171.       \  (MI    ni    liiirIi-frciiHi-iii-\    c-iirrrnt 


The  irrent  eniployeil  in  the  follou'inii  case  treated  by  the  authoi' 
was  not  a  hi'_:'h-l  t'eijueiicv  luit  a  vibratory  current,  having  a  similar 
l  hi -ra pi  it  i  '  •  if '  d  : ii  i  hi.-  class  ot  case-.  I  In •  pat  lent  was  an  old  woman 
a'  St.  !'>,:!'' r  >!  >.'!  i' "A  -  ('lime,  who  had  undergone  an  opei'alioii  for 
e\ten-l\'e  '  iln  rciilo.-is  of  the  dof-al  vertcbi'a1  seven  months  previously. 
A  di  "  '  '  -'ill  remained,  and  throimh  ii  (he  prone  found  an 

e\ti-u-]\'e    area    oi     -oftefii'd    bone,       I  he    treatment     consisted    in    the 
ibi    n    one   llol/.knecht    unit   ot    fays    No.  ^   1'ieimi-t    from 
an  .r-rav  tube  placed  at  a  distance  oi    Id  indies    from  the  anticathode  to 
.in   '  •/.  ici    a    '.'.  ei  ',,        (in   i  he  -a  me  da  \  -.   and   al-o  on   one  oi  her  da  \' 
each    '''••'.     ii    •  electrode  connected   \\nh   one   pole  of  the  ,c-rav 

coil   wa-  applied  •'  <  r  'he  affected  area   tor  about    ten   minutes.      The 


Hicii-FinxH'KxrY   rruKK.vrs  581 

<pmt  remeter  of  the  coil  was  set  so  that  any  secondary  current  in  excess 
of  tluit  required  to  produce  a  .'5-inch  spark  would  pass  across  the  gap 
between  the  poles  ol  the  coll.  This  acted  as  a  safety-valve  to  pre- 
vent an  undesirably  strong  current  from  passing  through  the  vacuum 
electrode  to  the  patient.  The  Oudin  resonator  would  have  been  ;t 
better  source  of  high-frequency  currents  for  this  case,  but  was  not 
available.  With  the  Oudin  or  the  d  '. \rsonval  the  current  should  be 
almost  '200  ma.:  the  electrode  should  be  kept  in  motion  and  the  appli- 
cation last  about  ten  minutes.  The  result  in  this  case  was  permanent 
closure  of  the  sinus  in  about  three  weeks.  The  possibility  of  an  effect 
upon  the  spinal  cord  of  course  had  to  be  considered  in  determining 
whether  to  use  the  .r-ray  in  this  case,  and  it  certainly  would  not  have  been 
wise  to  continue  its  use  for  any  great  period  of  t  ime.  Jn  such  conditions 
of  the  bones  it  seems  as  if  the  beneficial  effect  was  in  the  nature  of  an 
increased  action  by  the  tissues,  resulting  in  the  molecular  removal  of 
the  diseased  parts,  and  healing  by  some  such  process  as  takes  place 
normally  after  the  occurrence  of  a  simple  abscess  of  the  soft  parts. 
The  .r-ray  and  high-frequency  currents  are  indicated  in  many  case-  of 
bone  tuberculosis  with  sinus  which  are  not  in  a  condition  requiring  im- 
mediate operation  or  which  have  persisted  after  an  operation.  The  same 
combination  is  of  benefit  in  some  cases  of  tubercular  joint  disease, 
probably  most  often  in  cases  characterized  by  pain  and  stiffness  with- 
out much  serous  effusion.  The  application  would  be  similar  to  that 
described  for  tuberculosis  of  the  spine,  but  the  .r-ray  should  be  applied 
a  little  longer  or  a  little  stronger  with  a  view  to  producing  a  slight 
cutaneous  reaction.  Especial  care  should  be  taken  in  applying  the 
.r-ray.  however,  not  to  produce  an  ulcerative  dermatitis. 

High-frequency  Currents  in  Heart  Disease. — A  condenser  electrode 
from  the  d '. Vrsonval  transformer  may  be  applied  over  the  region  of  the 
heart  in  organic  heart  disease  without  arteriosclerosis.  It  generally 
gives  good  results,  and  even  reduces  cardiac  dilatation. 

Anf/ina  prctori*  has  been  apparently  cured  in  several  of  the  author's 
cases  by  rubbing  a  vacuum  electrode  over  the  entire  sin-face  of  the  chest 
and  applying  electric  vibratory  massage  to  the  abdomen  (Tousey. 

Young  persons  with  hypertension  and  presclerotic  patients  are 
benefited  by  general  d'Arsonvali/ation.  There  is  a  lowered  blood- 
pressure  without  any  change  in  the  pulse  rate.  The  general  symptoms 
improve. 

High-frequency  Currents  in  Gynecologic  Cases.-  I.rnl;<>rrhcn  and 
cervical  <r»xi<»tx  yield  readily  to  the  application  of  a  vaginal  vacuum 


electrode,  connected  with  the  Oudin  resonator  or  the  d  Arsonval  trans- 
former. If  the  latter  is  used  the  patient  holds  the  other  metal  electrode 
in  her  hand.  If  the  Oudin  is  used  the  patienl  is  connected  with  only 
one  electrode.  Ill  either  case  the  electrode  should  be  large  enough  to 
till  the  vairina  and  it  need  not  have  an  insulated  'double  walled  I  stein. 
The  current  should  be  !.">()  milliamperes,  and  should  be  applied  for 
ten  or  fifteen  minutes  with  intermissions  to  allow  the  electrode  to  cool. 


;>NJ  MF.DICAL    ELECTRICITY    AND    RONTGEN    RAYS 

A  certain  amount  of  massage  is  often  beneficial,  and  this  may  be  pro- 
duced by  moving  the  electrode  in  various  directions.  The  treatments 

should  be  given  three  nine.-  a  week,  and  should  be  suspended  during 
menstruation.  The  position  for  the  patient  is  upon  her  back,  \vith  the 
Ices  raised  and  resting  upon  crutches,  as  described  in  the  paragraph  on 
rectal  treatment  'p.  (ill).  It  i>  much  pleasanter  to  introduce  the 
electrode  before  the  current  has  been  turned  on,  avoiding  the  sparks 
which  wi  >ul<  1  i  it  herwise  occur. 

M i  ti'orrfnti/iii.  -Cast's  due  to  small  h'bromyomata  or  fibrocystic 
tumors  iir  without  apparent  cause  have  been  successfully  treated.1 
An  ordinary  copper  electrode  is  introduced  into  the  uterus,  the  vaginal 
portion  beiiui  insulated  by  a  rubber  tube.  The  high-frequency  appara- 
tus may  be  connected  with  a  static  machine  or  with  an  ./'-ray  coil,  and 
the  application  should  last  about  ten  minutes  and  be  repeated  once 
or  twice.  If  a  static  machine  is  used  the  application  will  probably 
have  to  be  of  the  full  available  strength,  but  with  a  coil  it  should  be 
regulated  .-0  that  a  current  of  about  150  milliamperes  -hull  pass  through 
the  copper  electrode.  The  cases  required  only  two  or  three  treatments, 
and  in  all  three  reported  the  effect  appears  to  have  been  permanent. 
Other  observers  have  not  iced  an  uncertainty  about  t  his  effect  in  different 
cases,  and. -till  others  i. \postoli  and  the  present  authon  have  noticed 
a  well-marked  emmenagogue  action  from  high-frequency  currents. 
This  may  not  be  the  case,  however,  when  applied  in  the  cavity  of  the 
11  tern-. 

I''  I >'i<  K.i'nilud  N.  -These  case-  can  very  often  be  saved  from  an 
operation  by  this  treatment.  The  vacuum  electrode  ha.-  an  insulated 
stein,  and  the  portion  from  which  the  current  emerge-  is  about  2.1 
inches  lom_i  and  -'  inch  in  diameter.  No  speculum  is  required,  the  tip 
of  the  electrode  being  pushed  up  into  the  vairmal  fornix  as  close  as 
possible  to  the  lesion,  and  then  a  current  ol  150  milliamperes  i.-  turned 
on.  This  may  be  a  unipolar  application  from  the  Oudin,  or.  if  from 
the  d  Arsonval,  the  patient  must  hold  the  other  electrode.  After  five 
minute-'  vaginal  treatment  a  similar  application  of  200  milliamperes 
:  n  ade  over  the  lower  part  of  the  abdomen  for  ten  or  fifteen  minutes. 
Powder  i-  used  to  secure  a  good  contact  and  allow  the  vacuum  elec- 
trode to  be  moved  rapidly  over  the  surface  without  .-parking.  The 
pain!  il  area  is  especiallv  treated.  Mehet  oi  pain  and  improvement 
in  -':''•!!  L1 t  li  are  verv  prompt,  and  some  weeks  later  the  gynecologist  is 
:•'.•  to  -ee  the  difference,  produced  locallv.  It  -ecms  probable  that 
thi-  i-  the  lie-t  electric  application  for  these  cases,  and  the  author  has 
cun  :-•.•;.-  had  pcrsi-ted  after  operation  and  all  kinds  of  medicinal 

appli'-at  ion-. 

••''/.  'I  lie  au'lior  sir^Lr''st-  the  use  o|  high-frequency  currents 
it!  f-a-i  -  in  '.vhich  there  i-  no  assignable  cause  for  sterility  or  in  which 
flii1  -uppo-i  'I  cause  h,-i-  liren  removed  bv  surgical  measuies.  It  slimu- 
late-  iterine  ;IM(]  ovarian  function-  but  also  acts  as  a  tonic 

upon  •  he  •.'.  ho! i   -••.•-tem.     The  large  uninsulated  vaginal  vacuum  electrode 
•.nil   a    current    ot     ].)0    milhampcres   tor  ten    minutes 

I  hfee  '  1  !!!'•-   a    '.'  ee[,;  I  1  e  1 1  a>  -een   t  1 1 1  -  t  fea  t  lliell  t     followei  1   by  1  he  prompt 

'    '     01). 

and    ;ft.rninn    of    the    type    which    will    yield    to    manual 

manipulation   -houl'i   find   in   high-frequency  currents  a   most    valual>le 

1  F.-iiichi.n  V.  [i-tiii   nftici"!   df  la  Sucicti'   francai-c  <!'.•],. cu-ioite,  Feb., 


HIGH-FREQUENCY    CURRENTS  583 

adjunct  to  tho  other  treatment  by  manipulation  and  tampons,  etc. 
The  same  large  uninsulated  vacuum  electrode  is  to  be  used,  and  a 
current  of  150  milliamperes  is  to  be  applied  for  ten  minutes  three  times 
a  week.  The  effect  is  to  improve  muscular  tone  and  to  cause  the  ab- 
sorpt  ion  of  infiltrates. 

General  and  Local  Trophic  Diseases. — These;  are  amenable  to 
d'Arsonvali/ation.  with  a  tension  of  :$<),()()()  to  50,000  volts,  .'300  to  700 
milliamperes,  and  over  500, 000  alternations  a  second. 

M i/.rc(lcni(t. — This  disease  is  favorably  influenced  by  general  d'Ar- 
sonvalization. 

Raynaud's  Dixcuxc. — Autocondensation  for  ten  minutes  at  a  treat- 
ment and  persisted  in  for  twelve  to  one  hundred  and  twenty-five  treat- 
ments, extending  over  periods  of  from  one  to  twenty-four  months,  has 
been  reported  as  uniformly  successful  in  cases  dependent  upon  con- 
traction of  the  arterioles  and  capillaries.1  Cases  dependent  upon  tro- 
phic changes  consequent  upon  arterial  thrombosis  or  other  obliteration 
give  good  results  if  treated  by  high-tension  high-frequency  effiuves  or 
fine  sparks.  The  glass  vacuum  electrodes  with  an  Oudin  resonator 
make  an  excellent  means  of  application. 

Prognosis.— The  disease  is  an  exceedingly  grave  one,  causing  loss  of 
one  or  both  limbs  at  successive  levels.  These  newer  methods  of  treat- 
ment have  not  been  used  in  a  sufficient  number  of  cases  to  make  it  possi- 
ble to  say  that  they  will  cure  every  case,  but  the  results  have  been  so 
good  that  they  should  be  faithfully  persisted  in.  A  careful  differential 
diagnosis  should  be  made  with  a  view  to  selecting  the  best  mode  of 
application. 

Injuries  and  Diseases  of  Joints  Treated  by  High-frequency  Cur- 
rents.— The  application  of  the  Oudin  resonator  current  by  a  glass  vacuum 
electrode  is  useful  in  the  subacute  and  chronic  stage  of  all  these  cases. 
A  remarkable  example  was  the  cure  of  a  ease  of  recurrent  dislocation  of 
the  patella  with  chronic  hydrarthrosis.2  The  high-frequency  applica- 
tion, known  as  thermopenetration  (page  (>31\  is  especially  effective  in 
the  treatment  of  gonorrheal  arthritis  and  of  gouty  deposits  about  the 
joints. 

High-frequency  Currents  in  the  Treatment  of  Genito-urinary 
Diseases. — Chronic  Orchitix  or  fcjtiditli/n/i/i*.--  The  author  has  suc- 
cessfully treated  cases  of  long-standing  swelling  due  to  injury  The 
treatment  has  been  by  a  combination  of  the  ./'-ray  and  high-frequency 
currents,  and  care  has  been  taken  to  shield  the  sound  testis  from  the 
.r-ray  by  ./'-ray  metal.  In  the  light  of  the  recent  discovery  that  the 
.r-ray  produces  sterility  by  killing  the  spermato/oa  a  great  deal  of  judg- 
ment is  required  in  determining  whether  to  use  the  .r-ray  as  a  part  of 
the  treatment.  It  certainly  should  not  be  applied  in  causes  of  a  simple 
chronic  inflammatory  tvpe.  Hut  in  the  more  threatening  cases,  where 
the  treatment  may  save  the  patient  from  an  operation  for  the  removal 
of  the  testis.  the  .r-ray  should  certainlv  be  combined  with  the  high-fre- 
quency currents.  The  method  of  application  is  by  exposure  of  the 
testis  through  a  hole  in  a  large  sheet  of  .r-ray  metal,  the  tube  being 
at  a  distance  of  about  10  inches,  ravs  No.  5  Henoist.  With  a  J  2-inch 
coil,  a  YYehnelt  interrupter,  and  the  primary  winding  giving  the  greatest 
inductance.,  a  primary  current  of  •'!  amperes  and  a  current  of  1  or 
2  milliamperes  passing  through  the  .r-ray  tube  the  exposure  would 

1  Bonnefoy,  Bulletin  Oflicicl  <lc  hi  Soc.  franc,  d  Vlcctrothcrapic  ct  <lc  radio!..  1<)()7. 

2  Tousoy, 'New  York  Medical  .Iminuil,  March  .">,  11*10,  p.  408. 


MKDICAI.    KLKCTHIC1TY    AND    H()NT(iKN    KAYS 


l>c  one  or  two  minutes,  or  III,  t  hree  times  a  week.  The  high-frequency 
ap]);ir;itus  might  he  the  d'Arsonval  transformer,  in  \vhicli  case  the 
patient,  lying  on  his  hack,  would  hold  a  metallic  electrode,  while  the 
ot her  elect  rode,  a  glass  vacuum  tube  in  an  insulated  handle,  is  applied 
over  that  entire  side  of  the  scrotum.  About  12")  milliamperes  would 
be  the  proper  strength  of  current  with  the  d'Arsonval.  A  spark- 
effect  is  to  !»e  avoided,  the  electrode  should  be  kept  in  motion,  the 
application  should  last  about  ten  minutes,  and  should  be  made  three 
limes  a  week.  The  ,r-ray  is  especially  effective  as  an  alterative  and 
high-frequency  cm-rents  as  an  eliminative.  The  combination  would 
be  ideal  in  all  these  cases  were  it  nor  for  the  drawback  mentioned 
above,  and  which  makes  it  desirable  in  many  cases  to  use  the  high-fre- 
ijuencv  currents  alone. 

7  itht  rt'ttloxtfi  and  /'iim'tr  <>t  nn/j  /xi/i  <>/  tin  t/i  mtu-uri  unrij  ti'tii't  are 
favorably  influenced  by  high-frequency  <  '.irrents  a.-  an  adjunct  to 
r-ray  treatment.  The  amount  of  pus  and  epithelial  detritus  which 
will  be  gotten  rid  of  by  a  single  combined  treatment  in  a  case  of  tuber- 
culosis of  the  bladder  or  kidney  is  astonishing,  and  the  subsequent 
clearing  of  the  urine  and  the  relief  of  pain  and  the  improvement  in 
regard  to  frequency  of  micturition  are  most  gratify  ing.  The  vacuum 
electrode  is  applied  over  the  kidney  or  bladder,  as  the  case  mav  be,  and 
in  the  latter  case  a  rectal  electrode,  either  vacuum  or  of  solid  metal,  is 
efficacious.  A  current  of  !")()  to  200  milliamperes  is  to  be  applied  over 
thi1  kldliev;  about  1 .")()  milliamperes  over  the  bladder;  the  electrode  IS 

to  be  kept  in  motion;  and  the  application  is  to  last  fifteen  minutes 
three  times  a  week.  The  current  for  rectal  use  is  about  1  ">0  milliainpereK 
with  a  vacuum  elect  rode,  and  may  be  much  st  rouge r,  up  to  100  milliam- 
peres, with  a  metal  electrode  and  d'Arsonval  current. 

Thfse  two  diseases,  tuberculosis  and  cancer  of  the  gemto-unnai'v 
system,  are  further  discussed  in  t  he  sect  ion  on  ./'-ray  t  re;,t  ment . 

S  [xisniixlir  xtrift  arc  mav  often  be  cured  bv  high-frequency  currents. 
Kither  a  rectal  or  a  urethra!  electrode  may  be  used.  The  latter  may 
In-  either  a  ulass  vacuum  electrode  or  an  electrode  consisting  of  a 


metal  roil  covered  wit  h  hard  rubber.  The  latter  type  gives  a  shower  of 
line  spark-  even  when  m  contact  with  the  mucous  membrane.  A  cur- 
rent oi  100  milliamperes  mav  be  applied  m  the  urethra  for  about  five 
minute-;  three  time-  a  week.  The  current  should  be  interrupted  occa- 
-lonallvto  prevent  i  he  elect  rode  from  getting  too  hot.  ami  some  greasv 
lubricant,  like  ravelin,  i-  better  than  any  of  those  which  are  soluble 
m  wat'-r,  \  lubricant  of  the  latter  character  will  sometimes  be  dried 
ip  by  the  |,i  v  oj  ',\\c  current  and  it  will  be  difficult  or  painful  to  remove 

the  electrode. 

dimnrrtim.      \  \  i-li  -frequency  current  s  have   so  decided    a    bactericide 

1  "      '    in   laboratory   work   that    it    i-  only  natural   that    they  should   have 

been   applied     •     ijie    treatment    of  gonorrhea.      Sudnik  '    treats    such   a 

ih'-  p<  ms  m   moi-t    ab.-orbent   cotton,  over  which  is  a 

sheet    ot    /me    to    wliich    the   current    is  conducted,  or  the   penis  is  in  a 

•  Aim   i]  i  ..'<••'•' il)i'ilnt£ic.  vol.  ii.  p  ;;i:;,     uote. |  l>v  I-p-uinl. 


HIGH-FKKQl  KNCY    (TUKKNTS  585 

U'lass  tube  with  a  metallic  bottom  and  containing  boric  acid  solution. 
One  wire  is  connected  with  the  metal  bottom  of  the  tube,  while  the  wire 
from  the  other  pole  of  the  d'Arsonval  transformer  leads  to  a  metal 
plate,  which  is  placed  over  the  perineum.  In  women  Sudnik  uses  a 
moist  tampon  large  enough  to  distend  the  vagina  and  secure  contact 
with  the  entire  mucous  membrane.  This  is  connected  with  one  pole 
of  the  d'Arsonval  transformer,  while  the  other  metal  electrode  is  placed 
over  the  hypogastrium.  His  results  have  been  very  good,  the  gonococci 
being  killed  almost  immediately,  but  t  he  discharge  persist  ing  for  a  week 
or  two  longer.  Burdick1  has  1  reated  obst  in  ate  cases  of  gonorrhea:  ( 1 )  I)u" 
to  streptococcus  in  pure  culture;  this  yielded  rapidly  to  treatment  by  a 
glass  urethral  electrode  and  Oudin  resonator.  ('2)  Mixed  streptococcus 
and  gonococcus  infection;  did  not  yield  to  high-frequency  currents,  but 
did  yield  to  the  x-ray  applied  so  strongly  as  to  produce  a  painful  reac- 
tion upon  the  mucous  membrane.  ('.))  Gonococci  mixed  with  tubercle 
bacilli;  high-frequency  currents  failed,  and  rather  a.  high  vacuum  jr-ray 
t  ube  caused  a  cure  in  seven  or  eight  days.  In  t  he  female  high-frequency 
currents  from  vacuum  electrodes  in  the  vagina  sometimes  caused  a 
cure  in  two  treatments.  In  a  case  treated  bv  the  present  author  the 
./•-ray  and  high-frequency  currents  proved  ineffective  against  gonococci. 
The  technic  consisted  in  the  application  of  rays  \o.  5  Benoist  every 
three  days,  the  length  and  strength  of  the  applications  being  such  as 
to  just  fall  short  of  producing  a  reaction  upon,  the  skin;  and  the  use 
of  a  urethral  electrode  connected  with  the  Oudin  resonator.  The 
t  real  ment  was  begun  during  the  first  week,  and  was  continued  for  several 
weeks  without  causing  the  disappearance  of  the  gonococci.  It  was 
noticeable,  however,  that  the  discharge  and  pain  were  very  much  dimin- 
ished by  the  first  treatment,  and  never  returned  to  any  extent.  The 
patient  had  had  several  previous  attacks  of  gonorrhea. 

A  better  method,  introduced  by  Sudnik,2  employs  the  bipolar  d'Ar- 
sonval current.  A  metallic  electrode  is,  pressed  against  the  perineum, 
and  the  wire  from  the  other  pole  of  the  high-frequency  apparatus  is 
connected  with  a  metal  douche  bag  from  which  a  urethral  injection  is 
given.  The  beneficial  effects  are  independent  of  the  nature  of  the  fluid 
injected.  A  twenty-minute  application  is  necessary,  and  it  should  be 
as  strong  as  possible.  Sudnik  uses  a  14-inch  induction-coil  and  4  large 
Leyden  jars  to  excite  his  high-frequency  apparatus.  Sometimes  in 
cases  in  which  treatment  is  applied  at  the  commencement  of  the  dis- 
ease there  an1  less  discharge  and  shreds  after  the  first  treatment,  but 
generally  the  improvement  is  gradual. 

Fiili/unit/on  in  I'd  pillonid  of  the  Blmlilt  r. -  Leo  Buerger  and  A.  L. 
A\olbarst:;  and  Kdwin  Beer1  were  among  the  first  to  report  the  applica- 
tion of  high-frequency  sparks  in  the  treatment  of  papilloma  of  the1 
bladder.  The  applicator  is  passed  through  a  cystoscope,  and  consists 
of  a  metal  point  at  the  end  of  a  flexible  shaft  made  up  of  a  spiral  spring 
covered  with  rubber  tubing.  The  Oudin  re-onator  is  adjusted  to  give  a 
hot  spark  only  i  inch  long.  The  applications  last  about  five  minutes 
for  a  large  papilloma  and  only  a  few  seconds  for  a  tiny  growth. 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

Dr.  H.  D.  Kumiss1  reports  the  application  of  fulguration  for  freeing 
a  calculus  impacted  at  the  vesical  end  of  the  ureter.  A  stream  of  sparks 
produced  suflicient  destruction  of  the  overlying  mucous  membrane  to 
allow  the  stone  to  escape  a  few  days  later. 

The  bladder  should  be  full  of  water  during  fulguration. 

(.'i/xtiti.*.--  An  instructive  case  is  reported  by  Crane.-  A  lady  of  fifty 
had  suffered  for  four  months  from  very  frequent  and  painful  urination. 
especially  at  night.  The  urine  was  alkaline  and  contained  of)  per  cent, 
of  pus.  A  slender  vacuum  tube  was  introduced  into  the  bladder  and 
the  current  from  the  Oudin  resonator  applied  for  fifteen  minutes.  She' 
slept  nearly  all  night  and  could  urinate  without  pain.  Twenty  treat- 
ments, combined  with  the  internal  administration  of  urotropin,  effected 
a  complete  cure.  This  agrees  with  the  author's  experience  in  more 
serious  bladder  cases,  in  which  the  vacuum  electrode  has  been  intro- 
duced into  the  rectum  or  applied  over  the  lo  ,ver  part  of  the  abdomen. 


Fig.  37-L  — Dimmer's  rectal 


is.—  Doumer1  reports  most  favorable  results  in  122  cases  of 
acute,  subacute,  and  chronic  prostatitis,  congestion  of  the  prostate,  and 
prostatitis  with  vesiculitis.  One  method  employs  a  metallic  electrode 
(Fig.  :->74),  passed  into  the  rectum  a  distance  of  about  2  inches,  and 
connected  with  the  Oudin  resonator  and  the  strongest  current  and 
rather  long  treatments,  eight  to  twelve  minutes.  Another  method  is 
bv  means  of  an  electrode  with  a  glass  sleeve  (Fig.  :!"">);  care  must  be 


taken  not  io  use  a  current  strong  enough  to  puncture  the  glass  or  to 
produce  too  iireal  a  sensation  of  warmth.  Such  an  electrode  may  be 
connected  with  a  resonator,  but  the  latter  should  be  regulated  to  pro- 
duce much  less  than  its  maximum  discharge,  efiluve  without'  sparks, 
and  the  application.-  should  not  be  longer  than  three  io  six  minutes. 
Morion  wave-currents  from  a  static  machine,  or  similar  currents  from 
one  pole  of  the  d ' A rsonval  transformer  while  the  patient  holds  an- 
ot  her  elect  rode,  give  results  similar  to  those  from  the  Oudm  resonator, 
h  It  are  |e.-~  convenient  and  are  less  agreeable  to  the  patient. 

.[fiftlu-iiti'titi  of  tin  .[m-xlli<-fir  !\u>  ••/  <>f  ///'<///-/''"/"""'//  ( ' urrcnts  Afi<r 
-,l'l .  i.  .  The  irritation  from  the  latter  treatment  mav  be 
relieved  by  the  immediate  use  of  a  metallic  sound  connected  with  the 
Oudin  re.- 1  ilia  lor. 

[fi  itnl  mill  //I/XI/K  ('ii/'ru/i.  (Jeneral  treatment  b\-  means  of  the 
aut  ocotiden.-at  ion  couch  or  ot  the  aut  ocondud  ion  cage,  together  with 
local  application-  of  the  eflluve  or  vacuum  electrodes  from  the  Oudin 


HIGH-FREQUENCY    CURRENTS  587 

resonator,  have  received  credit  for  the  recovery  of  certain  patients.1 
Certain  it  is  that  the  systemic  condition  of  lithiasis  is  favorably  influ- 
enced by  tliis  treatment.  Additions  to  calculi  already  present  may  well 
be  prevented  and  the  treatment  may  favor  the  passage  of  some  and,  if 
possible,  the  absorption  of  others.  In  taking  a  radiograph  of  a  case 
with  suspected  renal  calculus  it  has  occasionally  happened  that  a  stone 
has  been  passed  within  a  day  or  so  after  exposure  to  the  x-ray.  During 
the  exposure  the  patient  receives  not  only  x-rays  but  also  an  electro- 
static charge,  which  is  very  similar  to  that  derived  from  a  high-frequency 
apparatus.  It  seems  probable  that  high-frequency  currents  have  some 
local  beneficial  action  in  the  two  ways  indicated,  but  this  cannot  be 
regarded  as  definitely  proved. 

Impotence. — High-frequency  currents  yield  good  results  in  many 
cases,  although,  of  course,  there  are  some  which  seem  to  be  incurable. 
An  example  of  the  benefit  to  be  obtained  in  even  a  bad  case  is  cited 
on  page  u'13.  The  usual  teelmic  employs  an  Oudin  resonator  and  a  glass 
vacuum  electrode  applied  successively  to  the  scrotum  and  penis  and  to 
the  dorsal  and  lumbar  regions  of  the  spine  and  in  the  rectum.  There  is 
no  other  connection  made  with  the  patient.  He  had  better  lie  on  his  back 
during  the  application  to  the  rectum  and  genitals  and  the  current 
should  be  about  150  milliamperes.  This  should  be  applied  for  five 
minutes  in  the  rectum  and  for  about  ten  minutes  over  the  genitals. 
At  first  no  response  may  be  evident,  but  after  six  or  eight  treatments 
vigorous  erections  are  produced  during  the  application.  Along  the 
spine  the  current  may  be  of  200  milliamperes  and  with  a  certain  amount 
of  spark-effect  and  is  continued  for  ten  minutes.  The  electrode  is  kepti 
in  constant  motion  over  the  genitals  and  along  the  spine,  but  need  not 
be  moved  during  the  rectal  application,  but  the  current  should  be 
turned  off  two  or  three  times  to  keep  the  rectal  electrode  from  getting 
too  hot. 

High-frequency  Currents  in  Diseases  of  the  Nervous  System. — 
Neurasthenia  with  High  Arterial  Tension. — This  is  a  condition  in  which 
dental  infection  is  to  be  suspected,  and  to  be  searched  for  with  the  x-ray. 
According  to  Clay,  "the  presence  in  the  blood  of  alimentary  toxins— 
generally  acid  and  with  a  vasoconstrictor  effect — and  the  retention  of 
extractive  substances  of  the  xantho-uric  series  will  cause  hypertension. 
Not  only  does  uric  acid  cause  functional  hypertension,  which  may  be- 
come permanent  and  result  in  arteriosclerosis  or  atheroma,  but  chronic 
lead-  or  tobacco-poisoning,  interstitial  nephritis,  retention  of  chlorids, 
and  hyperactivity  of  the  renal  capsules,  cause  similar  conditions.  A 
temporary  increase  in  blood-pressure  occurs  before  each  menstrual 
period  and  at  the  menopause." 

Five  cases,  published  by  (lidon,'-'  of  Caen,  France,  showed  a  perma- 
nent reduction  of  arterial  tension  from  240  down  to  KiO  mm.  of  mercury. 
Added  to  this  there  was  relief  of  all  the  subjective  symptoms  which 
patients  had  suffered  from  hypertension.  The  number  of  treatments 
required  varied  from  five  to  sixteen  and  the  method  was  by  autocon- 
duction.  The  first  patient  was  a  man  about  forty,  large  and  somewhat 
corpulent,  and  a  little  eczematous,  who  suffered  especially  from  muscular 
weakness  and  constant  pseudo-asthmatic  shortness  of  breath,  (lidon 
had  treated  him  successfully  with  the  high-tension  eflluve  for  different 

1  MoutitT,  BoiiiK'foy,  d'. \rsonval,  etc. 

-  AmuH'  Medicale  de  Caen,  Dec.,  1904,  and  Journal  dc  Physiotlu'rapic,  March 

15,  i no.-). 


;,s\  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

articular  pains.  The  patient  had  taken  the  milk  cure  t'or  hepatic  trouble. 
The  heai't  \\  as  normal.  1  Ie  t'ormerly  used  to  eat  ;uul  drink  rather  exces- 
sively, no\v  more  moderately,  hut  not  according  to  any  regular  regimen. 
His  diet  was  not  modified  at  all  during  the  high-frequency  treatment. 
He  had  always  digested  everything  very  well,  (iidon  attributes  the 
slowness  with  which  the  arterial  tension  was  reduced  to  the  unregu- 
lated regimen.  After  eight  treatments  the  patient  was  free  from  all 
the  symptoms  except  the  ec/.ema.  During  the  final  treatments,  besides 
the  autoconduct ion  cage,  local  application.-  were  made  with  an  effluver 
with  a  u'la.-s  sleeve:  this  soon  relieved  the  ec/.ema  and  the  patient 
stopped  coming.  There  had  been  three  treatments  a  week.  The 
*n-i>t/d  patient  showed  a  rapid  tall  in  blood-pressure  with  only  one 
treatment  a  week.  He  complained  of  a  nervous  diarrhea,  spinal  hy- 
peresthesia.  and  muscular  weakness,  especially  in  the  morning.  He 
was  a  pseudoneurasthenie  with  hypertension.  The  diarrhea  and  the 
debility  disappeared  after  the  first  treatment,  and  finally  the  spinal 
hyperest  hesia  was  cured.  The  third  patient  received  three  treatments 
a  week.  He  was  thin,  on  an  insufficient  dietary  was  constantly  cyanotic. 
and  had  acute  attacks  of  dyspnea  at  night,  \\alking  was  difficult  on 
account  of  dvspnea.  and  the  trouble  seemed  to  have  been  brought  on 
originally  by  overexert  ion.  There  had  been  attacks  of  pulmonary 
congestion  and  of  acute  nephritis.  The  heart  action  was  rapid  and 
suggestive  of  Bright 's  disease  and  very  arhythmic.  Treatment  was 
bv  aiitoconduct  ion  and  benefited  the  arhythmia  very  much,  caused  the 
disappearance  of  cyanosis,  and  improved  the  dyspnea  so  that  the  man 
could  walk  rapidly  for  several  minutes.  The  night  attacks  disappeared. 
The  nature  of  the  dietary,  which  was  partly  milk,  was  not  changed 
durimr  the  treatment.  The  fourth  patient  was  a  man  ot  sixtv:  hemi- 
plegic;  had  had  two  serious  congestive  attacks  during  the  last  two 
years,  and  his  high  arterial  ten.-ioii  evidently  exposed  him  to  the  danger 
iif  another.  There  was  spastic  paralysis  ot  the  arm  and  leg  and  intense 
mental  excitability,  especially  at  night.  '1  he  cerebral  condition  was 
improved  from  the  moment  the  high-frequency  treatment  was  begun. 
The  spasmodic  contraction-  were  relieved  and  walking  became  much 
easier.  Constipation  was  relieved.  There  was  only  one  treatment 
a  week.  Diet  was  moderate  as  to  quantity,  but  unrestricted  as  to 
nature.  '1  he  /•'/'//,  patient  was  a  vouni:  man  who  was  very  stout  and 
who  per.-isird  in  overindulgence  as  to  diet.  He  was  gouty,  dyspneic. 
albummuric,  and  had  taken  the  cure  at  \ichv  for  attack-  of  severe 
.'•  trouble.  He  sought  treatment  on  account  ot  the  gout,  which 
u'a-  -o  had  thai  he  could  scarcely  walk.  Autoconduct  ion  bv  inean- 
ot  a  cane  connected  with  the  d  Arsoiival  t  ran.-tormei1  was  applied  three 
'her  with  ihe  high-frequency  eflluve  from  the  Oudin 
the  painful  joints,  and  a  few  -inu-oidal  applications. 
much  reduction  in  arterial  tension  until  i  he  thirteenth 
HIT  thai  lime  the  joints  were  so  much  relieved  that 
\  could  be  applied,  and  from  that  lime  the  blood-pres- 
lo  about  normal,  the  patient  became  able  to  breathe 
well,  and  became  thinner,  although  still  weighing 
111-  pi  T-i-t  ence  in  overeating  was  the  cause  of  the 
;  d  rial  pn '--ii re. 

•  •    value  "t  high-t  reqiiencx   currents  in  i  he  treat- 
it  h  hir_:h  arterial  ten -ion  is  large!  V  due  to  I  he  pub- 


HICH-FRKQrKNCY    CURRENTS 

lished  observations  of  Moutior,1  of  Mouticr  and  ( 'hallamol,-  and  of  ( lay.:; 
A  neurasthenic  wit  h  high  a  fieri  a  I  tension  does  not  need  t  he  rest  cure,  and 
i.-  to  he  regarded  not  as  {ill  enfeebled  hut  as  a  poisoned  person  ((lay). 
No  other  means  is  nearly  so  effective  as  high-frequency  currents  in 
causing  t  he  elimination  of  irritant  -uhst  ances  and  t  he  restoration  of  t  he 
normal  blood-pressure.  L'nder  this  treatment  there  are  increased  cellular 
activity  and  increased  respiratory  movements  and  chemic  exchange.-. 
The  oxyhemoglobin  in  the  blood  increases  and  there  is  increased  elimi- 
nation of  carbon  dioxid.  The  same  increased  elimination  is  shown  bv 
changes  m  t  he  urine  resulting  from  more  complete  oxidi/at  ion  of  organic 
substances  in  the  system.  There  is  an  increased  amount  of  urea,  (lav 
gives  a  detailed  account  of  the  result  of  treatment  in  12  cases  of  neuras- 
thenia with  high  tension,  and  the  subject  is  so  import  ant  t  hat  his  oh.-er- 
vat  ion  should  he  recorded  here.  1 1  is  high-frequency  a  p  pa  rat  us  consisted 
of  a  10-inch  RuhmkorlT  coil  with  a  \\  ehnelt  interrupter,  condensers,  and 
a  large  d  Arsonval  solenoid  or  autoconduction  cage  inside  which  the 
patient  was  placed.  A  primary  current  of  d  amperes  and  a  secondary 
current  of  :>.">()  to  100  niilhamperes  were  used,  and  the  application  lasted 
twenty-five  minutes  everv  other  day.  ( 'ase  1:  Man  aged  twenlv-one. 
salesman,  alcoholic  ancestry,  two  brothers  consumptive,  himself  a 
drinker  and  onamst.  For  six  months  he  had  Miffered  from  a  sensation 
as  of  a  leaden  helmet  on  his  head  and  a  general  feeling  of  lack  of  strength. 
Melancholia  and  tendency  toward  suicide.  Well  nourished  and  well 
developed.  \o  anomaly  of  sensation,  tendon  reflexes  slightly  exag- 
gerated, pupils  normal,  no  Romberg  symptom  (difficulty  of  equilib- 
rium when  the  eyes  are  closed).  In  ten  treatments  the  following 
changes  took  place:  pulse  rate,  from  70  to  S0;  blood-pressure,  from 
H)0  to  \'2()  millimeters  of  mercury:  daily  amount  of  urine,  from  1MOO 
to  IdOO  cc.;  chlorids.  from  d  to  10  grams  per  liter:  phosphates,  normal 
before  and  after:  sulphates  the  same;  urea,  from  12  to  Id  grams  per 
liter:  uric  acid,  from  o  to  1  --',,",,-  grams  per  liter.  The  subjective  symp- 
toms all  improved.  Case  '2:  The  pulse  rate  changed  from  SO  to  72 
and  the  blood-pressure  from  ISO  to  135  millimeters  in  fifteen  treatments. 
I'ric  acid  from  .1  to  2  grams  per  liter  and  urea  unchanged  from  Id  grains 
per  liter.  Similar  changes  were  produced  in  all  \'2  cases,  and  in  several 
which  he  had  an  opportunity  to  see  some  months  after  treatment  the 
improvement  had  been  permanent. 

A  series  of  observations  by  Moutior  and  Challamel  upon  a  large 
number  of  patients  showed  a  reduction  in  blood-pressure  of  oO.  40.  or 
.10  millimeters  after  the  first  treatment  by  the  autoconduction  cage, 
and  of  onlv  1"),  20.  or  oO  millimeters  after  the  first  treatment  by  the 
autocondensation  couch.  To  verify  this  advantage  of  the  cage  over  the 
couch  they  were  able  to  obtain  an  additional  reduction  of  ;">,  If).  20.  or 
o5  millimeters  by  an  application  with  the  cage  alter  reduction  by  the 

1  1 .  Arch,  d VI eetrieite  medical e.  No.  !.">(),  Sopt.  I  ">,  I !H) 4,  communication  to  the 
Medical  Congress  ;it  (in-noble.  "Arteriosclerosis  treated  !>y  d'Arsonvali/ation." 
_'.  .  \reli.  dVleetrieite  ineilicale,  I'eh.  1  .">  and  Sept.  1  .">.  I'.MI.'I.  :>.  "  PsouiloniMiras- 
I  henia  with  urterial  liypeiMcu-ii  >\\."  Connnunieat  ion  to  ttie  Socicte  niodirah1  IN 
urr..  session  ni  April  \'2.  I'.MIO.  1.  "  Neurast  henia. "  ci  minninieat  ion  to  the  Soejrie 
Medico-chinir<:icalo  de  Paris,  session  of  Oct. 'JS,  1(101.  ">.  Zcit -clirin  fiir  Klektro- 
iherapie,  vol.  vii.  No.  L',  I'.M)."). 

-  (i.  Arch,  d 'elect  ricil  e  iiHnlicale.  Xo.  K'rJ,  Marcli  2.">.  I'.M).").  ^'Comparison  be"- 
i  \veen  autoconduction  and  autorondensat  ion  in  arterial  hypertension.'1 

1  7.    Arch,  il'rlortririte  tnedicale.  April  _'.">.   I"11- 


">90  MEDICAL    ELECTRICITY    AND    K(")NTGEN    HAYS 

couch.  Moutier  recommends  five  or  ten  minutes  for  each  application 
and  that  they  should  he  given  three1  times  a  week.  Neurasthenia  with 
high  arterial  tension  he  calls  "neurasthenia." 

The  presence  of  this  symptom  calls  for  the  application  of  high- 
frequency  currents  of  comparatively  low  tension.  The  d'Arsonval 
autoconduction  cage  and  autocondensation  couch  an*  principally  em- 
ployed (these  have  heen  described  on  page  ")}.">  i,  hut  other  means 


Fin.  3iG.  —  -The  d'Arsonvnl  transformer  with  >in;ill  .-ulcnoid. 

are   also   used.     The   patient    may   -imply   hold  'two   metal   electrodes 
connected    with    the   terminal    of    the    small    solenoid    of   a    d'Arsonval 
apparatus  or  he  may  hold  one  metal  electrode  while  the  other  electrode, 
which   may  he  either  metallic  or  a  vacuum   tuho.  is  ruhhed  over  the 
epigastrium   and    along    the   spine.       Or   two   metallic    plate1   electrodes 
may  he  placed,  one  over  the  spine  and  the  other  over  the  epigastrium. 
(if.  following  the  author's   usual   custom,  the   patient    may  sit    upon  a 
metal  plate  electrode,  from  which  he  is  completely  insulated  hy  a  thin 
sheet  of  indurated  fihor,  and  may  rest  his  hack  against  a  similarly  insu- 
lated   plale  elect  rode.      Kadi    electrode    is    connected    with    the    corres- 
ponding extremity  ol'  the  d'Arsonval  small  solenoid.      All  the  different 
methods   produce  the  same  oscillating  currents   in   the  hody.  either  hy 
direct  conduction  or  hy  induction.     The  autoconduction  cage  has  heen 
employed   in    Kurope,   hut    the  other  methods  are   more   usual   in 
:'•;;.       Kxactly    which    method    should    he    selected    depends    upon 
The   nature   ''I    the   case,   especially   upon    whether   some   local   effect    is 
de-in-d,    ;i-    well    as    the   effect    of   lowering    the   general    hlood-pressuro. 
I' hi    •     :  let  ion  in  arterial  tension  under  flie  application  of  d  '. \rsonval- 
ixaTion  i-  ;  ccon  ;  allied  h\-  a  sensation  oi  warmth  heginning  in  the  hands 
ii  ii'lurj:  to  the  hodv  and  the  lower  e\t  remit  ies.      Som- 
•     ha-    -howii    that    a    thermometer    hdd    in    the    hand    registers    an 
i.-eil      .   ;         ii  mperat ui'e.      At  the  same  time,  there  is  an  increased 
amplitude   in   the  capillary   pulse  and  diminished   tension   in   the  radial 


HIGH-FREQUENCY    CURRENTS  591 

current.  The  return  of  function  in  the  nerve  was  generally  expected  to 
take  place  spontaneously  if  at  all.  and  was  thought  to  he  only  assisted 
by  treatment.  High-frequency  currents  produce  so  little  muscular  con- 
traction as  not  to  be  of  any  service  in  this  way.  They  do.  however, 
maintain  and  improve  the  nutrition  in  paralyzed  muscles,  and  seem  to 
have  an  effect  upon  the  return  of  function  in  the  nerve.  The  author's 
experience  has  been  largely  with  cases  of  Infantile  paralysis,  and  with 
cases  of  musculospiral  paralysis  from  pressure  and  facial  paralysis 
from  exposure.  In  these  cases  the  results  have  been  successful.  The 
application  for  paralysis  is  made  locally  by  glass  vacuum  electrodes 
applied  all  over  the  affected  muscles  and  over  the  spinal  centers  of  the 
affected  nerves.  Wider  observation  will  be  required  to  determine  the 
relative  advantages  of  the  high-frequency  current  and  the  galvanic 
and  galvanofaradic  currents.  The  vacuum  electrode  may  be  connected 
directly  with  one  pole  of  an  .r-ray  coil  or  is  connected  with  the  d'Arson- 
val  or  Oudin  apparatus.  A  current  of  about  loO  milliamperes  should 
be  used  for  about  fifteen  minutes  three  times  a  week.  Among  the  cases 
of  infantile  paralysis  may  be  mentioned  one  treated  at  St.  Bartholo- 
mew's clinic.  One  poor  little  hand  was  crippled  and  about  half  the 
natural  si/e,  and  the  leg  on  that  side  was  in  the  same  condition.  A 
few  months'  treatment  with  a  vacuum  electrode  connected  directly 
with  one  pole  of  an  .r-ray  coil  brought  the  paralyzed  arm  and  leg  up 
to  a  size  exceeding  those  of  the  normal  limbs  originally,  and  at  the  age 
of  two  and  a  half  years  the  boy  was  strong  and  jolly.  There  remained 
an  indefinable  evidence  of  the  previous  trouble  and  the  author  does 
not  know  whether  this  has  completely  disanpeared  or  not.  Cases  of 
longer  standing  with  deformities,  such  as  talip.es  equinus  from  contrac- 
tion of  the  muscles  opposed  to  the  paralyzed  ones,  of  course,  require 
mechanical  and  surgical  treatment  in  addition  to  the  application  of  elec- 
tricity, but  the  latter  is  a  valuable  adjunct. 

Parali/xix  Aijitdnx  (Parkinson's  Disease}. —  Doumer  and  Maes1  report 
a  case  very  much  benefited  by  atitoconduction  for  five  minutes  prac- 
tically every  day  for  five  weeks.  The  patient  was  an  old  man  of  seven!  y- 
two  with  the  classic  symptoms.  The  arterial  tension  became  normal 
and  all  symptoms  disappeared. 

Ep /Vc/;*//. — A  combination  of  the  .r-ray  ami  high-frequency  currents 
has  been  used  in  the  treatment  of  epilepsy,  and  the  results  reported 
by  Branth-  and  Tracy"  show  that  a  certain  amount  of  benefit  is  pro- 
duced. Tracy's  figures  show  a  percentage  of  tentative  cures  amounting 
to  2")  per  cent,  in  petit  mal,  20  per  cent,  in  .lacksonian  epilepsy,  and 
12  per  cent,  in  grand  mal.  In  these  cases  bromids  were  also  adminis- 
tered. In  a  disease  as  inveterate1  as  this  cures  must  be  substantiated 
by  prolonged  freedom  from  recurrence,  but  the  treatment  is  worth 
while,  even  if  the  benefit  does  not  prove  permanent .  An  .r-ray  tube  with 
a  high  vacuum  No.  C>  Benoist  and  a  moderate  strength  of  current  is 
placed  with  its  anticathode  10  inches  from  the  patient's  head  and  al- 
lowed to  shine  for  five  or  ten  minutes  (1  or  2  Ilolzknecht  units).  After 
this  high-frequency  currents  from  a  vacuum  electrode  connected  either 
with  the  d'Arsonval  transformer  or  the  Oudin  resonator  are  applied 

1  Jour,  do  Physiothc'rapie,  November  !.">,  1905. 

2  Now  York  Medical  Journal,  1901. 

3  Ibid.,  March  1,  1904. 


~>')2  MKDICAL    KLKCTKKITY    AM)    KOVHiKN    HAYS 

over  the  brain  for  ten  minutes  and  along  the  spine  for  live  minutes.  A 
current  of  1")0  milliamperes  is  used.  This  treatment  should  be  given 
three  times  a  week,  but  the  .r-ray  cannot  be  continued  very  long  be- 
cau-e  ot  the  likelihood  of  causing  permanent  alopecia.' 

("hurt  a.  This  is  a  disease  in  which  the  general  tome  effect  ot  high- 
frequency  currents  is  peculiarly  beneficial,  and  the  author. has  treated 
many  cas<  -  \\  it  h  uniform  success.  The  application  has  been  made  by  a 
vacuum  electrode  connected  in  some  cases  with  vibratory  currents 
from  one  pole  of  an  .r-rav  coil,  and  in  ot  her  case-  with  high-frequency  cur- 
rent.- from  the  d'Arsonval  transformer  or  the  (  hidin  resonator.  The 
results  have  been  equally  good.  A  current  of  ].">()  milliamperes  is  applied 
for  fifteen  minutes  along  the  spine  and  over  the  limbs,  and  while  po\\- 
der  i-  used  to  enable  t  he  electrode  to  glide  nicely  over  the  surface,  a 

certain  amount  of -park-effect  is  desirable.  This  should  not  be  sufficient 
to  be  disagreeable  or  to  bring  out  little  red  ooints  upon  the  skin.  The 
treatments  should  be  given  t  hree  times  a  week.  Improvement  i.-  rapid 
and.  uniform.  This  method  mav  be  recommended  in  any  case,  but  the 
a  ithor  does  not  mean  to  say  that  no  other  form  oi  electricity  would 
1  ii  •  a-  g<  iod  m  -i  line  cast  -s. 

/,«•«'«'"•  Atii.fin .  The  author  has  t  reat ed  cases  of  this  disease  by 
a  combination  of  the  .r-ray  and  high-frequency  currents.  Marked 
improvement  ha-  resulted,  so  that  the  patient's  friend-  have  stopped 
him  on  the  -treet  and  asked  him  what  treatment  he  was  receiving;  but 

the]'  a  cure  can  be  effected  in  such  cases  remains  to  be  seen.  The 
improvement  was  especially  noticeable  in  regard  to  the  gait  and  the 
lightning  pain-.  The  girdle  sensation  persisted,  bin  the  lack  of  coordi- 
nation was  benefited,  and  in  one  case  seen  two  years  alter  the  cessa- 
tion of  treatment,  the  patient  was  able  to  perlorm  the  delicate 
movements  required  in  shaving.  The  technic  in  these  cases  has  been 
the  application  of  .r-ra  vs.  \d.  i>  or  7  Renoi-t .  over  t  he  -pine  at  the  lower 
level  of  'he  scapula  twice  a  week,  of  such  a  duration  and  intensity  as 
will  produce  only  the  slightest  redness  of  the  skin  after  three  weeks' 
ise.  then  discontinuing  the  use  of  the  ./--ray  lor  three  weeks  and  taking 
again  in  the  same  way.  Vibratory  currents  were  applied  from  a 
ode  connected  directly  with  one  pole  (it  the  .r-ray  coil, 
the  current  being  about  h">0  milliamperes.  and  some  little  spark-effect 
isi-d.  This  current  was  applied  to  the  lower  extremities  and 
a  lot  m  the  -pine  for  fift  een  mm  ut  es  t  hree  t  lines  a  week  (on  the  same  days 
as  the  .r-ray.  and  one  extra  day  each  week-.  The  only  improvements 

In  tin    in-atme-nt  of  I'pilep.-y  it   is  of  (lie  utmost  importance  to  search   for  and 
••  "  ovi       ny  i-xeii    \\<r  causc<.       \  ca.-e  in  point   i-  that   of  a    man   of    t  \\enly--ix.  sent 
i  o  m'-  !  ron  i  t ),,.  count  ry  \\  it  h  a  hi-t  <  >ry  ot  having  I  >een  wounded  in  the  Spanish  \Yar. 
•  j          :    '••    ;  I'-nl    epilept  ifunii    ci  mvulsii  m-    or   chorea    major   since    then. 
ioe,i   every  three  ueek-  Mini    u-ually    l'ollo\\i-d    -otne    -lii_dit    injurv. 
liieycle       Aiini  her  t  ime  In-  cauirht   hi-  fintrcr  in  a  c-ofT-wlu'cl 
I  i    •   nir  t  In    convul-ioTi-  he  made  friirhl  I   il   noi-e-  ;; in |  foamed  at  tin- 
•  •   -in  four  t  n  -is  LT1 "  "1  nn 'ti  lo  hold  him.  \\  hili-  it   t  ook  t  he  doct  or 
•    the  influence  of   niorphin   and    chloroform       After   tin- 
ti'co^ni/e  iii-  friend-.  \<  M    more   often    [,,     ,jj,|    ,,,,(    \\ake    up 
d    lieen    ireati'd    un-ucce--fully    I  >y    mixed    liromid-   and 
•   in    it  riiein        I       imina!  ii'i  r\    t  i-ht    prepuce, 

iliundant    \\hite    uati-ry    di-charir<-.    the    dan-    l>eini:    fairly 
••••  Iceratien-         \    r-ircumci-ion    i  fleeted    MII    in-tant    and 

;  .  •          [,.-n-    r  ..,- 


HIGH-FREQUENCY    CURRENTS  593 

that  the  author  would  surest  in  this  technic  would  he  the  use  of  the 
Oudiii  resotuitor  and  the  application  of  a  high-frequency  current  of 
'_'(>()  milliamperes  without  much  spark-effect,  keeping  the  glass  electrode 
111  motion;  and  the  application  of  a  quantity  oi  the  .r-ray  actually 
measured,  as  by  I  lol/knecht  's  chromoradiometer,  and  amounting  to 
a  little  less  than  111.  twice  a  week.  The  anticathode  of  the  tube  is 
about  1  1  inches  from  the  skin,  no  locali/er  being  used.  In  inexperienced 
hands  the  .r-ray  should  not  be  applied  over  the  spine.  It  is  not  at  all 
probable  that  pathologic  changes  can  be  produced  in  the  spinal  cord 
by  rays  which  do  not  injure  the  skin,  but  at  the  same  time  it  would 
be  unwise  for  one  who  was  not  sure  of  the  strength  of  ray  produced  by 
his  apparatus  to  take  the  risk. 

.Y<  '//•// /'.s  <in<l  XcuritUjid. — The  author  has  treated  a  great  many  cases 
coining  under  these  headings.  Usually  the  results  are  excellent  and 
the  improvement  prompt.  Occasionally  a  case  will  be  found  to  experi- 
ence somewhat  more  pain  after  the  first  one  or  two  applications  and 
then  to  do  perfectly  well.  In  other  cases,  after  a  reasonable  trial,  the 
high-frequency  currents  may  be  abandoned  and,  as  in  certain  cases  of 
long-standing  facial  neuralgia,  static  electricity  will  effect  an  immediate 
cure.  The  .r-ray  has  done  great  service  in  cases  of  pain  about  the  face 
by  enabling  one  to  examine  the  condition  of  the  teeth,  the  bones  of  the 
face,  and  their  various  pneumatic  sinuses,  (luided  by  this  means,  no 
time  is  wasted  in  treating  by  electricity  a  case  in  which  an  operation  is 
the  only  proper  thing.  Such  cases  may  be  suppuration  of  the  antruni 
or  of  the  frontal  sinus,  impacted  teeth,  abscess  about  the  apex  of  the 
root  of  a  tooth,  an  improper  root-filling  (insufficient  or  penetrating 
the  tooth  either  at  the  side  or  the  apex  of  the  root),  or  a  tumor,  abscess, 
or  cyst  of  any  of  the  bones.  The  .r-ray  does  not  show  the  condition 
of  the  nerve  directly,  but  enables  us  to  exclude  certain  other  lesions 
and  narrow  the  diagnosis  down  to  that  of  a  painful  affection  of  the 
nerve  itself.  This  may  have  more  or  less  of  an  anatomic  basis,  according 
to  whether  the  case  is  one  of  neuritis  or  neuralgia.  The  method  of 
application  may  have  to  be  varied  for  different  cases,  the  local  applica- 
tion by  the  effhive  or  from  a  vacuum  electrode  being  usually  much 
more  effective  than  the  general  application  by  autoconduction  or 
autocondensat  ion.  In  this  regard  the  high-frequency  current  differs 
from  static  electricity,  a  general  application  of  which  is  often  more 
effective  than  a  local  one  in  these  cases.  In  many  cases  of  sciatica, 
lumbago,  neuralgic  pains  in  the  face.  neck,  or  limbs  the  author  lia> 
obtained  excellent  results  from  the  direct  application  of  the  vacuum 
electrode  to  the  point  of  exit  of  the  nerve  and  all  over  the  painful  area. 
These  results  have  ensued  whether  there  was  just  a  single  glass  vacuum 
electrode  connected  directlv  with  one  pole  of  .r-ray  coil,  o;  with  the 
( hidin  resonator  (Fig.  377),  or  whether  the  d'Arsonval  transformer 
was  used.  \Yith  the  last-named  apparatus  the  patient  holds  a  metal- 
lic electrode  in  one  hand  while  the  glass  elect  rode  from  the  other  pole 
of  the  apparatus  is  applied  to  the  affected  region.  In  any  case  the 
skin  should  be  powdered  and  a  current  of  '_'()()  milliamperes  applied 
during  fifteen  minutes  for  sciatica,  or  1">I)  milliampere.-  during  six 
minutes  for  trigeminal  neuralgia.  This  should  be  given  every  other 
day.  Two  or  three  weeks  usually  see-  the  milder  cases  cured,  while 
those  of  long  standing  may  take  two  or  three  months.  The  strength 
of  current  prescribed  is  that  which  actuallv  passes  through  the  glass 


594 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


vacuum  electrode.  There  should  be  but  a  slight  spark-effect.  The 
pain-relieving  property  of  hitrh-frequency  currents  and  their  tendency 
to  relax  spasm,  together  \vith  the  fact  that  they  do  not  cause  muscular 
contraction  or  any  di.-amveable  sensation,  make  them  the  method  of 


MI  'i:<n!  of  :i[>]>lvniu  higli-frfijur 

hese    cases.      An    extreme    c 


Kx**'^<*mimmm 

higli-frfijurnry  CHrn.-iit.-    in    triuu'ial  tx-uraljria. 

xtreme    case    is    reported    bv    Somerv 
eakness.    and    anesthesia    impi'oved 


choice    in    tese    cases.      An    extreme    case     s    re 
in    \\!i!''h    alaxia.    muscular    weakness.    and    ane 
much     under    t  rcat  mi-nl     by     hi^h-frequency 
bewail    •.'.!•;.    numbner-s   and   weaknes<   in   one   le 
t  \venty-one   years  old.   to   resign   his   position   a,- 
quence  oi    e\  i  n  )sii  re   in   a    1'aiiisionn    the  conditi 
;ind  In-  \va.-  confined   to  \><-<\  \\nii  motor  and  se 

'' 


ases.      An    extreme    case     s    reporte      bv    Somerville,1 
muscular    weakness.    and    anesthesia    impi'oved    verv 

at  mi-nl     by     hi^h-frequency     currents.     The    trouble 
ner-s   and   weaknes<   in   one   leu,    causing   the   patient, 
old.   to   resign   his   position   a,-  a   postman.      In   conse- 
re  in   a    1'aiiisionn    the  condition   became   much  worse 
ned   to  \><-<\  \\nii  motor  and  sensory  paralv.-is  of  both 
.  as  well  as  both  lejrs.     'I'lie  symptoms  did  not   indi- 
taxia.    but    rather   peripheral    neuritis.      'I'hei-e   w;is    no 


HIGH-FREQUENCY    CURRENTS  595 

when  the  application  is  made  locally  by  the  vacuum  electrode.  The 
effect  of  the  autoconduction  cage  or  the  autocondonsation  couch  is 
systemic  and,  of  course,  will  be  suitable  in  some  cases,  while  it  is  con- 
traindicatod  in  others.  The  local  benefit  would  not  be  obtained  if  the 
application  affected  the  general  nervous  system  unfavorably.  The  local 
application  hardly  over  fails  to  have  a  favorable  influence  on  the  general 
condition,  and  while  not  always  successful,  there  is  no  class  of  cases  in 
which  it  is  especially  likely  to  fail. 

The  high-frequency  application,  known  as  thormopenetration  (page 
031)  has  often  given  good  results  in  the  author's  practice.  It  is  especially 
suitable  for  eases  with  one  or  more  definite1  painful  areas;  while  the 
other  cases  with  general  pain  and  weakness  in  an  entire  limb  are  treated 
by  the  slow  sinusoidal  current  and  four-cell  bath. 

X'eiii'dlt/id. —  Bipolar  effluviation  from  double  resonators  or  double 
spirals  may  be  followed  by  sparks  from  a  nionopoiar  Oudin  resonator. 
A  method  which  has  succeeded  well  in  the  author's  hands  has  been  bv 
a  glass  vacuum  electrode  connected  with  a  nionopoiar  Oudin  resonator. 
The  voltage  and  amperage  have  to  be  carefully  studied  for  each  case. 
X  fiirdli/id  of  the  Lumbar  l*lexux.  —  Heavy  galvanic  currents  may 
bo  used. 

High-frequency  currents  may  be  applied  from  the  d'Arsonval 
transformer.  The  patient  holds  a  metallic  electrode  while  the  wire 
from  the  other  terminal  leads  to  a  plate  electrode  covered  with  wet 
cotton  which  is  applied  to  the  lumbar  region.  Or  the  glass  vacuum 
electrode  may  be  substituted  for  1  he  moistened  plate  electrode. 

Chrotiir  Sfinfir  Xeto'dlfiid.—Thi*  is  bv  far  the  best  application  for 
these  cases.  Suitable  methods  of  application  are: 

I.  Autocondonsation  for  about  five  minutes,  the  patient  sitting 
upon  the  insulating  indurated  fiber  covering  a  sheet  of  metal  while 
his  back  rests  against  another.  Tin's  the  author  follows  by  a  mild  or 
strong  application  of  a  glass  vacuum  electrode  from  the(  luilleminol  s|  nral 
along  the  course  of  the  sciatic  nerve  and  its  branches.  Whether  to 
redden  the  skin  or  not  is  a  question  to  be  derided  in  each  individual 
case,  but  generally  mild  applications  are  the  more  beneficial.  Five 
minutes  is  about  the  propel'  duration.  Vibratory  massage  along  the 
course  of  the  nerve  in  the  thigh  is  a  desirable  addition  in  some  cases. 

'2.  A  method  recommended  by  Albert  \\eill  employs  first  a  bipolar 
effluve  and  then  nionopoiar  sparks.  A  larire  plate  electrode  from  the 
pole  of  one  of  the  resonators  or  spirals  is  directly  in  contact  with  the 
lumbar  region,  and  a  brush  electrode  or  efiluve  is  held  near  successive 
parts  of  the  painful  region  until  the  latter  is  all  reddened.  This  anes- 
thetizes the  skin  to  a  certain  extent  and  prevents  pain  from  the  second 
part  of  the  treatment.  A  series  of  large  white  nionopoiar  sparks  are 
applied  along  the  nerve.  These  turn  the  skin  white,  but  it  soon  becomes 
vividly  congested  and  the  sciatic  pain  is  immediately  relieved  and  the 
patient  able  to  walk  better  than  he  could.  Some  ot  the  improvement 
persists  until  the  next  treatment.  Applications  are  made  at  first 
every  day,  then  three  times  a  week,  and  a  complete  cure  is  to  be 
expect  0(1. 

Si'intir  Xcurititt. — The  d'Arsonval  apparatus  is  used,  giving  a  bipo- 
lar high-frequency  but  comparatively  low-tension  discharge.  One  wire 
passes  to  a  sheet  of  lead  or  tin  applied  directly  to  the  lumbar  region 
and  tlie  other  to  a  similar  electrode  fastened  to  the  le^  below  the  calf. 


•  nib  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

The  milliamperemeter  should  indicate  a  current  of  300  or  400  or  more  ma. 
and  the  application  should  last  about  ten  minutes.  Bordier  recom- 
mends this  met  hod  very  .-!  roiigly. 

The  mildest  application  of  a  glass  vacuum  electrode  connected 
with  a  monopolar  (luilleminot  .-piral  and  with  an  adjustmenl  of  appara- 
tu-  i:ivim:  a  discharge  of  l"»(l  ma.  with  scarcelv  anv  spark-effect  has 
given  wonderful  re.-ult-  ill  the  hands  of  the  author.  One  case  of  two 
years'  standing  was  cured  in  seven  application.-  and  remain.-  well  now. 
three  years  later. 

I n*uniniti.-  \\hen  this  condition  occurs  as  a  >ymptom  of  any  dis- 
ea-e  in  which  high-frequency  currents  are  indicated,  it  is  usually  cured 
\iy  -uch  treatment.  Tliis  happened  in  a  case  of  gast  ric  atony  treated 
liy  the  author.  The  application  was  by  a  vacuum  electrode  connected 
with  the  (  hidin  resonator,  the  electrode  being  passed  over  the  abdomen 
and  along  the  upper  |iart  of  the  dorsal  region  of  the  spine.  But  where 
insomnia  is  the  chief  symptom  and  almost  constitutes  a  disease  it  is  not 
always  best  to  treat  it  by  high-frequency  currents.  In  an}'  case  the 
method  of  application  must  be  carefully  studied.  Somerville,1  using 
'•aiffe's  transformer  and  high-frequency  apparatus  with  MM)  to  1000 
milliamperes  passing  through  the  autocondensation  couch,  has  succeeded 
with  such  cases  after  fifteen  to  thirty  treatments.  Drowsiness  is  not 
always  one  of  the  results  of  high-frequency  currents  and  improvement 
in  regard  to  sleeplessness  comes  as  the  result  of  a  number  of  treatments. 
The  application  does  not.  like  hypnotic  drugs,  induce  an  unnatural  sleep. 
but  rests  and  invigorates  the  patient,  and  >o  brings  about  natural 
sleep.  Too  lonu  or  too  strong  an  application  of  high-frequency  currents 
i-  liable  to  cause  sleeplessness  by  its  effect  upon  the  circulation  in  the 
brain.  The  application  of  a  glass  vacuum  electrode,  with  a  current 
of  !.")()  milliamperes,  to  the  back  of  the  neck  and  head  for  about  five 
minutes  will  almost  always  have  a  reflex  soothing  effect.  This  will 
tend  to  produce  sleep  through  an  effect  on  the  nervous  system. 

I'niniu!  (  'onilitioii*  .\<>f  /if  \irri  Orir/in.-  I'll  iiritir  JHII'HX  are  well 
treated  bv  the  gla.-s  electrode  with  L'lid  milliamperes  from  the  Oudin 
resonator  for  t en  minute.-  every  ot  her  day. 

I'liinfiil  /fnf-ftxil  is  one  of  the  condition-  m  which  the  application 
'•••  tin  vacuum  electrode  i-  of  the  tireatest  benefit.  A  current  of  b~>0 
milhampere-  i-  applied  for  fifteen  minutes  to  the  toot  and  leg  three 
time-  a  week.  The  apparatus  may  be  either  the  d'. \r-onval  t  rails- 
•  or  t  he  (  ludiii  re-onat  or  or  the  vacuum  elect  rode  may  be  connected 
directly  ui'h  one  pole  of  an  r-ray  coil.  I'owiler  should  be  used  and 
Dill  the  -lightest  -park-effect  allowed.  There  may  be  some  advan- 
:.  i.-iiiL:  the  d"Arson\"al  transformer  and  having  I  he  patient  hold 
the  •••;.•'  metallic  electrode.  In  the  author's  cases  llu-  has  seemed 
a  hn]e  more  ionic  effect  than  the  unipolar  ajjplication. 
it  plate-  are,  of  course,  a  necessity  in  these  cases.  When  the 
eaknes.-,  as  shou  11  b\'  pain  and  the  characteristic 
the  combined  electric  treatment  and  mechanic  support: 
verv  promptly,  and  eventually  effect  a  complete 
li'-i  -;  '•  di.-ease  i-  of  lom:  duration  and  there  is  deformity 
-  iriiieal  operation  ma\'  be  nece.-c^U'\  before  electricity  is 


HIGH-FKKQtENCY    CURRENTS  597 

High-frequency  Currents  in  the  Treatment  of  Cicatricial  and 
Fibrous  Conditions. — Dupuytrcn's  Contraction. —  This  is  a  condition 
which  occurs  in  middle  or  advanced  life  and  is  due  to  u  contraction  of 
the  palmar  fascia,  with  adhesions  to  one  or  more  of  the  flexor  tendons 
and  to  the  skin.  It  is  evident  on  looking  at  the  hand,  and  especially 
so  when  an  attempt  is  made  to  fully  flex  or  extend  the  finders.  Herd- 
man1  has  treated  these  cases  successfully  by  high-frequency  currents  and 
calls  attention  to  the  fact  that  the  trouble  is  not  a  contraction  of  the 
tendon,  for  it  is  the  proximal  phalanx  of  the  finder  that  is  flexed,  and  no 
position  of  the  hand  will  permit  it  to  be  extended.  Then,  again,  con- 
traction of  the  tendon  would  not  cause  the  prominence  of  the  tendon 
which  is  seen  in  these  cases.  A  rheumatic  or  gouty  tendency  is  usually 
found  in  such  cases  and  sometimes  neuritis  of  the  ulnar  nerve.  The 
local  condition  is  a  chronic  inflammatory  process  due  to  the  systemic 
state,  and  bearing  no  distinct  relation  to  the  use  which  may  be  made 
of  the  hand  in  the  patient's  daily  life.  The  role  of  high-frequency  cur- 
rents in  the  treatment  is  to  cure  the  constitutional  tendency.  A  suitable 
application  is  made  by  means  of  the  autoconduction  cage  or  the  auto- 
condensation  couch.  The  author  has  more  frequently  used  the  vacuum 
electrode,  applying  a  current  of  150  to  200  over  about  a  quarter  of  the 
surface  of  the  body  during  fifteen  minutes.  The  surface  is  powdered 
and  the  electrode  kept  in  motion.  The  use  of  the  tissue  oscillator 
over  the  hips  and  lower  part  of  the  back  for  a  couple  of  minutes  is  a  most 
desirable  addition.  The  galvanic  current  with  negative  electrolysis, 
using  only  a  few  milliamperes,  has  cured  the  local  condition. 

High-frequency  Currents  in  the  Treatment  of  Certain  Con- 
stitutioual  Diseases. — Diabetes. — Static  electricity  and  high-frequency 
currents  are  both  of  value  in  diabetes,  but  should  probably  be  lim- 
ited to  cases  in  which  metabolism  is  slowed.  They  may  do  harm  in 
cases  where  there  is  exaggerated  denutrition  and  the  examination  of 
the  urine  shows  a  nitrogenous  coefficient  higher  than  the  normal. 
DeRenzi  and  others  have  seen  the  return  of  sugar  caused  by  high- 
frequency  applications  in  such  cases. 

Conflicting  reports  have  appeared  in  regard  to  the  efficacy  of  the 
treatment  in  this  disease.  D'Arsonval  reported  2  successful  cases  as 
long  ago  as  1S9(>.  Both  feet  rested  in  a  bath  to  which  one  electrode 
went:  and  the  other  electrode,  a  forked  one.  was  held  by  both  hands. 
Apostoli,  at  the  Twelfth  International  Medical  Congress,  reported 
success  in  over  500  cases.  Autoconduction  cages  or  autocondensation 
couches  were  used  and  the  average  number  of  treatments  was  twenty- 
five.  Following  Apostoli,  several  of  his  pupils  and  assistants  have  re- 
ported successful  results.  Some  others  who  have  succeeded  with  it  are 
Williams.-  Allen;1  and  the  present  author.  On  the  other  hand,  Boedeker, 
Colin.  Loewy,  Douiner,'1  and  more  recently  Halfon/'  have  reported  that 
high-frequency  currents  produced  no  reduction  in  the  amount  of  urine, 
r'reund  i"  Radiotherapy")  does  not  express  an  opinion. 

The  author  knows  that  in  certain  cases  the  sugar  will  not  dis- 
appear, but  believes  that  even  in  these  cases  the  general  strength 

1  Archives  of  Physiologic  Therapy.  l-Vl>ruary,  MM)."). 

-  Iliph-frcquoncy  Currents  m  the  Treatment  oi  Some  Diseases. 

3  Radiotherapy,  etc. 

'  Annal.   d'elertrobiolotrie.   vol.   iii. 

'^  11  pro^resso  medico.  No.  :},  1903. 


O9S  MEDICAL    ELECTRICITY    AND    RONTGEN"    RAYS 

I 

and  the  cutaneous  and  other  disagreeable  symptoms  are  so  much 
benefited  as  to  make  high-frequency  currents  a  necessary  part  of  the 
treatment  of  every  case.  That  there  are  manv  other  cases  in  which 
the  sugar  disappears  in  a  most  wonderful  manner  is  equally  certain. 
It  ha>  not  been  the  author's  habit  to  ask  for  a  discontinuance  of  med- 
icinal treatment,  and  so  his  own  cases  can  hardly  be  cited  as  absolute 
proof  that  the  electric  treatment  alone  would  have  been  effective. 
Hut  what  he  is  able  to  say  is  that  cases  which  have  been  doing  very 
badlv  under  medicinal  treatment  alone  have  done  very  well  under  the 
combined  medicinal  and  electric  treatment.  One  such  case  was  that 
of  a  lady  about  forty  years  old  who  was  passing  about  .l(i  ounces  of 
urine  daily,  and  this  contained  10  per  cent,  of  suirar.  She  had  dis- 
tressing abdominal  symptoms  consisting  mostlv  of  pain  and  diarrhea. 
Three  weeks'  combined  treatment  by  medicines  and  the  .r-ray  and 
high-frequency  currents  reduced  the  amount  of  urine  to  ")•!  ounces  a 
day  and  the  sugar  to  less  than  1  per  cent.,  and  the  patient  left  for  her 
home  in  I'ortn  Uico  feeling  entirely  well  Another  similar  case  was 
that  of  a  gentleman  of  fifty-five  who  had  suffered  from  asthma  and 
dyspnea  for  a  month  or  two.  and  progressive  and  terrible  emaciation 
and  loss  of  strength.  He  had  lost  l2~)  pounds  in  six  weeks  and  the  urine 
if)1  ounces  a  day)  contained  10  per  cent,  of  sugar,  or  127-11  grains  per 
diem.  He  was  so  weak  that  his  wife  had  to  dre-s  him.  and  lie  was 
apparently  hurrving  toward  a  fatal  termination.  In  his  case  also  the 
x-ray  was  used  in  conjunction  with  high-frequency  currents,  and  the 
administration  of  arsenical  preparations  was  continued.  During 
the  next  two  and  a  half  weeks  there  was  practically  no  loss  of  weight 
—only  4  pounds — and  by  the  end  of  that  time  a  change  for  the  better 
set  in.  He  began  to  gain  weight  and  strength,  and  it  was  evident 
that  his  life  was  saved.  After  one  or  two  weeks  more  of  treatment 
by  high-frequency  currents  without  the  .r-ray  he  was  again  placed  in 
the  hands  of  his  regular  physician  for  treatment  by  static  electricity, 
and  made  a  irood  recovery. 

As  indicated  above,  the  French  operators  have  generally  made  use 
of  the  methods  of  general  electrification  which  employ  the  autocon- 
duction  caire  or  the  autocondensat  ion  couch,  and  if  either  of  these  are 
used  a  current  of  at  least  .100  to  800  milhamperes  should  be  applied;  and 
-hould  last  ih'teen  or  twenty  minutes  and  be  repeated  every 
The  author's  own  preference  is  for  the  .r-ray.  rays  \o.  5 
.  applied  over  the  abdomen  twice  a  week  with  the  anticathode 
ies  from  the  skin  and  the  applications  long  and  strong  enough 
luce  Mime  tanning  of  the  skin  in  three  weeks,  but  no  redness. 
half  the  normal  exposure  described  on  p.  L 1 .10  is  suitable  for 
The  vibratory  currents  in  both  ot  the  foregoing  cases  were1 
vacuum  electrode  connected  with  one  pole  of  ;tn  .r-ray 
'iirreni  of  about  1200  milliamperes  was  applied  over  the 
nd  down  the  -pine  (or  about  twenty  minutes  three 
The  skin  must  be  powdered  to  allow  the  electrode  to 
••urtace  \\nfioiit  sparking.  The  Oudin  resona- 
lent  when  as  heavv  a  current  as  this  is  desired 
equally  .u'ood  results.  Kven  in  cases  where 
d  I  he  percentage  o|  sugar  are  not  reduced  the 


HIGH-FREQUENCY    CURRENTS  599 

bly  the  disease  is  actually  cured  or  whether  the  patient  is  only  made 
practically  well.  Some  preparation  of  arsenic  seems  to  be  the  medic- 
inal agent  for  use  in  conjunct  ion  wit  h  the  electric  t  real  men t. 

Hhi'unititisni. — Jones'    considers    this    treatment    contraindicated    in 

acute  rheumatism  and  says  that  it  gives  good  results  in  chrome  rh<  u- 
matism.  but  requires  a  large  number  of  treatments,  twenty-five  to 
thiriv  at  least,  and  sometimes  two  or  three  hundred  (Apostoli  and 
Laqucrriere).  There  is  no  difference  of  opinion  in  regard  to  its  being 
of  value  in  chronic  rheumatism,  but  some  operators  think  that  it  has 
not  yet  been  shown  to  possess  any  advantages  over  other  forms  of 
electricity,  such  as  electric  baths  and  static  electricity.  The  conveni- 
ence of  application  and  the  ease  and  certainty  with  which  the  appli- 
cation can  be  regulated  make  this  the  ideal  method  of  treatment  if  it 
be  shown  to  be  effective.  Here,  as  in  other  constitutional  disorders, 
many  operators  employ  autocondensat  ion  or  autoconduct  ion,  but 
the  author  finds  the  application  of  the  glass  vacuum  electrode  to  the 
affected  joints  or  other  localities  and  then  over  the  abdomen  and 
along  the  spine  or  in  some  other  way  to  apply  it  to  a  large  part  of 
the  body  very  effective.  The  cases  which  have  been  treated  in  this 
way  have  been  referred  by  their  family  physicians  after  medicines, 
massage,  and  baths  had  failed  to  give  relief.  The  results  are  perma- 
nent, not  mere  temporary  stimulation  or  analgesia,  and  a  healthy 
action  of  the  tissue  cells  throughout  the  body  is  inaugurated  which 
results  in  continued  improvement  after  the  treatment  is  all  over.  In 
many  cases  there  will  be  wonderful  improvement  within  a  few  hours 
after  the  first  treatment,  and  this  improved  level  is  maintained  but 
not  materially  surpassed  for  about  three  weeks.  At  the  end  of  this 
time  a  gradual  and  uniform  improvement  begins  which  continues  as 
long  as  the  treatment  is  kept  up  and  for  some  time  afterward,  so  that 
often  the  patient  feels  better  a  year  after  the  treatment  was  stopped 
than  he  did  immediately  afterward.  Some  of  the  cases  which  have 
been  successfully  treated  have  had  pain  and  enlargement  and  stiffness  of 
several  of  the  large  joints  and  of  some  of  the  smaller  ones,  but  without 
serous  effusion.  The  symptoms  have  entirely  disappeared  except 
that  perhaps  some  one  finger  joint  may  remain  a  little  enlarged,  though 
painless.  Cases  with  rheumatic  synovitis  of  almost  every  joint  in 
the  body  and  of  many  years'  duration  may  be  very  much  benefited, 
although  in  some  of  these  a  cure  is  not  to  be  hoped  for.  The  benefit  is 
shown  by  the  prevention  of  the  acute  exacerbations  which  every  change 
of  weather  and  certain  other  conditions  bring  on.  There  is  also  a  return 
of  the  joints  to  about  the  normal  appearance  and  the  deposits  about 
the  sheaths  of  nerves  and  in  the  region  of  the  joints  is  removed  or 
diminished.  The  patient  becomes  able  to  sleep  and  his  general  con- 
dition improves  very  much.  From  being  sick  in  bed  from  a  tenth  to  a 
quarter  of  the  time,  such  a  patient  may  often  be  transformed  into  a 
condition  of  apparent  robust  health.  An  expert  examination  may 
show,  however,  that  the  synovial  membrane  of  nearly  evorv  joint  is 
still  thickened,  and  an  occupation  involving  prolonged  exposure  to 
cold  and  wet  would  be  liable  to  bring  on  an  acute  exacerbation. 

There  are  many  cases  which  other  means  have  failed  to  cure  and 
which  high-frequency  currents  will  cure   either   completely  or  practi- 


000  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

cally.      Other   cases   must    be   classed    as   incurable,    though    the}'    mny 
be  very  much  relieved  by  t  his  t  real  men  t. 

The  author's  method  of  treatment  has  been  published1  and  consists 
in  the  application  of  vacuum  electrodes  from  the  d  \\rsonval  trans- 
former or  Oudin  resonator  to  the  affected  joints  and  to  a  considerable 
portion  of  the  bodv:  tor  instance,  over  the  abdomen  and  along  the  spine. 
The  current  is  about  L'OO  milliamperes  and  the  application  requires 
from  one-quarter  to  one-half  hour.  With  this  is  applied  mechanic 
vibration  along  the  spine  and  perhaps  over  the  abdomen.  In  occasional 
cases  the  .r-rav  is  applied  to  remove  some  obstinate  and  painful  swelling 
about  one  particular  joint.  The  high-frequency  current  has  a  strength 
of  about  L'OO  milliamperes;  and  severe  cases  with  several  large  joints  to 
be  treated  require  an  application  of  about  one-half  hour.  A  certain 
amount  of  spark-effect  is  desirable  over  the  joints,  but  this  should  be 
only  the  fine  crackling  that  comes  when  a  <  onvex  electrode  is  in  good 
contact  with  only  a  portion  of  its  surface1  touching  the  skin.  The  skin 
should  be  powdered  and  the  electrode  kept  in  motion.  Treatment 
three  times  a  week  is  best,  but  twice  or  even  once  a  week  will  often 
accomplish  a  cure,  though  a  longer  time  may  be  required.  The  result 
is  due  partly  to  a  local  stimulant  and  counterirritant  effect  and  partly 
to  a  const  it  utional  effect .  By  t  he  lat  ter  the  defect  ive  processes  of  met- 
abolism are  corrected.  Nitrogenous  substances,  for  example,  leave  the 
bodv  completely  oxidized  as  urea,  instead  of  partly  oxidized  as  uric  acid. 
Whether  or  not  it  is  correct  to  regard  uric  acid  as  the  cause  of  rheuma- 
tism, it  seems  to  be  a  fact  that  it  is  present  in  the  tissues  and  excreta 
to  an  abnormal  extent  in  1  hese  cases,  and  t  hat  measures  which  result  in  its 
diminution  have  a  curative  effect  upon  the  disease.  Williams2  observed 
in  one  case  that  the  proportion  of  uric  acid  to  urea  in  the  urine  was  at 
first  I  to  ">]  and  gradually  changed  to  1  to  70.  then  gradually  changed 
all  t  lie  way  back  to  the  normal  ratio  of  1  to  ;;>.">.  The  change  accompanied 
the  recoverv  of  the  patient  from  a  case  of  chronic  rheumatism.  The 
symptoms  had  been  "rheumatic  fever  at  twenty-six  years;  now  at 
forty-eight  there  are  dyspepsia,  rheumatic  pains  all  over,  but  especially 
in  the  lumbar  region,  and  history  of  several  big-t  oe-jomt  attacks. 
Small  joints  all  more  or  less  enlarged.  Appetite  nil  and  sleep  bad." 
He  was  treated  bv  aut  ocondensat  ion  ten  minutes  dailv  with  a  current 
of  :;.">()  milliamperes;  and  in  seven  weeks  made  a  complete  recovery 
and  Drained  (>  \  pounds  in  weight . 

In  'he  majority  of  cases  treated  there  is  no  special  change  in  the 
daily  excretion  of  urea,  and  very  otten  the  examination  of  the  urine 

lie  rheumat  ism. 

al    Record  "  are 

with    a   family   history   in 
her  s  case  a  t    t  hirt  v-nme) , 
paralvsis    of    the  throat,  and  apoplexy,  on 
male    paternal    ancestors  bemjj;  laru'e  men. 


in 
10M.X0    F.     His 


HIGH-FKKQUENCY    CURRENTS  001 

present  trouble  dated  from  nti  attack  of  lumbago  two  years  afro.  He 
was  not  sick  in  bed,  but  any  movement  was  very  painful  in  the  morning, 
with  gradual  improvement  through  the  day.  The  symptoms  disappeared 
in  two  months.  Status  pnesens:  (J  feet  4  inches  in  height,  weight 
17")  pounds;  some  flat-foot  and  consequent  unusual  breadth  to  the  ball 
of  the  foot.  The  right  great  toe  joint  is  swollen  and  stiff  and  then-  is  a 
gouty  pain  in  it,  especially  on  awakening.  The  middle  toe;  of  the  right 
foot  has  a  sensation  as  of  slipping  out  of  joint.  Then1  is  a  rheumatic 
pain  in  the  right  hand.  These  symptoms  have  remained  so  aggra- 
vated, in  spite  of  medicinal  treatment,  as  to  threaten  to  incapacitate 
him  for  business.  Shortly  after  beginning  treatment  he  had  a  fall 
which  produced  a  severe  ecchymosis  of  the  left  thigh  and  stiffness  of 
the  knees  and  an  added  rheumatic  pain  in  the  left  hand.  The  treat- 
ment consisted  in  the  application  of  high-frequency  currents  and 
vibratory  massage  according  to  the  author's  uric-acid  tcchnic  and  the 
administration  of  10  grains  of  salophen  three  times  a  day;  the  avoid- 
ance of  tea,  coffee,  and  tobacco,  and  the  application  of  flat-foot  plates. 
At  the  end  of  a  month  the  gouty  pain  in  the  right  great  toe  had  almost 
disappeared;  only  a  trace  remained  of  the  rheumatic  pain  in  the  right 
hand,  and  the  rheumatic  pain  in  the  left  hand  brought  on  by  the  fall 
had  been  reduced  three-fourths.  After  another  two  weeks'  treatment 
the  patient  reported  himself  so  well  in  every  way  that  it  seemed  proper 
to  discontinue  the  treatment. 

The  very  marked  effect  of  the  first  treatment  was  produced  before 
he  had  begun  taking  salophen,  but  the  latter  is  a  valuable  adjunct 
in  these  cases.  The  patient  came  a  year  later  to  report  his  condition, 
which  was  excellent.  This  patient  and  the  next  one  were  in  private 
practice  and  were  cultivated  people,  but  accustomed  to  simple  rather 
than  luxurious  living. 

Another  patient  was  a  lady  of  fifty-four,  weighing  2S7  pounds,  and 
with  a  family  history  of  rheumatic  gout,  making  them  chair  invalids 
for  years.  Personally  she  had  always  been  careful  about  diet,  but  had 
gradually  become  more  and  more  affected  by  a  rheumatic  or  gouty 
condition  which,  in  spite  of  medical  treatment,  had  finally  crippled 
her.  For  some  time  previously  she  had  not  been  able  to  walk  more 
than  two  or  three  blocks  and  on  coming  to  a  curbstone  would  hesitate 
for  some  time  before  attempting  to  step  up  those  2  or  3  inches.  The 
knees  were  badly  swollen,  the  joints  of  both  feet  were  stiff  and  swollen, 
as  was  also  the  middle  finger  of  the  light  hand.  The  day  following  the 
first  treatment  she  was  walking  any  number  of  blocks,  going  up  and 
down  stall's,  and  "feeling  like  a  bird."  'Phis  was  before  she  had  begun 
taking  salophen.  The  original  brilliant  improvement  remained,  but 
was  not  surpassed  until  after  two  or  three  weeks  of  treatment  applied 
two  or  three  times  a  week.  Then  a  stead}'  advance  began.  The  local- 
ities exhibiting  the  slowest  progress  were  one  knee,  which  she  had 
strained  some  time  previously,  and  the  middle  linger  of  the  right  hand. 
'[  o  these  several  applications  of  the  .r-ray  were  made.  For  this  an 
s-inch  coil  was  used  with  a  Caldwell-Simon  interrupter  and  a  M filler 
heavy  target  tube  which  was  encased  in  a  localixing  shield.  The  holes 
111  the  interrupter  were  small  and  gave  a  primary  current  of  4  amperes 
with  rapid  interruptions,  rays  \o.  I  Henoist.  The  anticathode  was 
at  a  distance  of  9  inches  from  the  skin  with  exposures  for  two  min- 


t)()2  MKDICAL    ELKCTKICITY     AND     H(")NT(;EN     RAYS 

ute-  twice  a  week.     The  beneficial  effect   was  immediately  evidenced 
by  prompt   improvement    in  the  knee  and  finder. 

A  rilirtitnr  u.-ed  in  these  cases  was  made  by  Wappler.   of  Xew   ^  ork, 
it    has    a    ^.-hor.-e-power  motor,    a    flexible   shaft,    and    a    ball   extrem- 


ity in  which  an  exceiitric  weight  revolves.  The  ball  is  applied  lat- 
erally so  as  to  produce  1  he  effect  of  pressure  and  release  with  short 
rapid  strokes,  but  without  loss  of  contact.  The  speed  and  the  length 
of  the  stroke  i.-  regulated  for  each  case.  The  effect  is  to  stimulate 
any  nerve,  it'  il  is  applied  lightly  and  fora  ,-hort  time;  and  to  depress 
or  produce  a  sedative  effect  on  ativ  nerve  over  which  it  is  applied  with 
heavy  pressure  and  for  a  lom_r  time.  The  effect  of  vibration  in  rheu- 
mati.-m  i-  partK'  one  of  stimulation  of  the  general  metabolism,  and 
partly  also  an  effect  upon  the  trophic  center.-  in  the  spine,  which 
influence  all  the  tissues  of  the  different  joints  ihev  supplv.  Kven 
without  electric  or  other  special  devices  the  author  has  for  many 
year-  prescribed  m.i--a'_re  ot  the  posterior  roots  of  the  spinal  nerves 
for  cases  oi  rheumatism  of  the  knee,  for  example,  which  did  not  vield 
tc  medicine-  and  local  applications.  This  was  verv  successful  and 
mad--  it  ea-\  tor  him  to  believe  some  ot  the  claim.-  of  osteopathy  when 

..:-   promulgated. 

The  patient    -.'.a-   under  treatment     by  hmh-t  re<|iiencv    currents   and 

rnerliainc     vibration     for    four    month-,    and     at     the   end   of   that    time 

-'•<:;;•    1    i  el),    'hou'jh    ihere    remained    a     little     enlargement     of 

tin     joint    "i    the  middle  finder.      Manx     month-  afterward  she  reported 

health  and  siren;:!  h,  and   thinks  that    the  ^reate.-t 

benelii   came  'I'eainient    \\"a-   finished.      At    the   present    time, 

.     h'        more  eut  husia-t  ic  than  ever  about   it.    The  treat- 


HIGH-FREQUENCY    CURRENTS 


603 


ment  produces  a  permanent  change  in  the  system,  not  a  mere  temporary 
stimulation. 

()l>cxitij. — Arthritic  and  gouty  patients  suffering  from  obesity  are 
benefited  by  autoconduction  or  autoeondensation  or  by  the  general  ap- 
plication of  a  glass  vacuum  electrode  while  the  patient  holds  a  metallic 
electrode  connected  with  the  other  pole  of  the  d'Arsonval  Iran-former. 

Then1  is  sufficient  evidence 
that  autoeondensation  or  auto- 
conduction  will  reduce  the  size 
of  fat  people  by  stimulating  the 
processes  of  metabolism.  It  is 
uncertain,  however,  whether  a 
reduction  in  weight  may  be  regu- 
larly expected,  or  only  a  certain 
reduction  in  bulk.  Quite  exten- 
sive applications  with  the  vacuum 
electrode  proved  only  moderately 
successful  in  the  case  of  a  patient 
who  weighed  210  pounds,  though 
only  5  feet  4  inches  in  height, 
and  who  had  the  marked  som- 
nolence which  would  naturally  be 
expected.  He  would  go  to  sleep 
while  reading  the  newspaper,  or 
on  the  street  car  on  his  way  to 
be  treated,  or  in  the  reception 
room,  and  invariably  upon  the 
operating  table.  He  lost  G  pounds 
in  six  weeks'  treatment  and  im- 
proved materially  in  regard  to  the 
drowsiness.  It  seems  probable 
that  the  treatment  by  high-fre- 
quency currents  is  not  the  first 

choice   in   cases  of  obesity  unless  they  present    some 
for  it   in  addition  to  mere  weight. 

A  more  effective  method  of  treatment  is  by  mechanic  means,  and 
the  best  apparatus  is  a  tixsuc  oscillator.  This  has  a  powerful  electric 
motor,  the  speed  of  which  is  regulated  by  a  rheostat.  A  heavy  iron 
pillar  supports  a  revolving  shaft  and  the  pulleys  on  the  motor  and 
shaft  may  be  so  adjusted  as  to  give  from  .'$00  to  2  K)0  revolutions  a 
minute.  Close  to  each  end  of  the  shaft  is  fastened  a  pin  which  may 
be  adjusted  more  or  less  excent rically.  Two  handlebars  are  thus 
given  a  back-and-forth  motion,  the  length  of  stroke  being  set  at  from 
zero  to  an  inch  or  more.  For  certain  purposes  the  handles  mav  be 
held  in  the  two  hands  and  pulled  while  the  machine  is  put  in  very 
moderate  motion.  An  acute  attack  of  stiff  neck,  or  of  myalgia  about 
the  shoulder,  is  relieved  bv  three  or  four  minutes  of  this  application. 
For  most  [imposes  a  belt  is  attached  to  the  two  handlebars  and  passed 
around  the  patient,  who  steadies  himself  by  the  handles  and  lean-  all 
his  weight  against  the  belt.  For  obesity  the  belt  is  applied  over  the 
buttocks  for  five  minutes,  the  patient  facing  the  machine:  then  over 
the  abdomen  and  over  the  shoulders.  The  stroke  should  be  about 
\  inch  and  must  be  exact  Iv  even  on  both  sides.  The  adjustment  is 


special  indication 


604 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


such  that  one  side  pulls  as  the  other  relaxes.  If  the  proper  adjust- 
ment be  made  and  a  suitable  speed  <dven,  usually  about  1200  revolu- 
tion- a  minute,  the  patient  rests  quite  steadily  against  the  belt  and  is 
tiot  jolted  back  and  forth  at  all.  At  the  same  time  the  ilesh  under  the 
belt  is  moved  to  and  fro  laterally  and  there  is  a  general  tremor  <riven 
to  the  whole  body.  The  local  effect  is  to  brin<:  the  blood  to  the  sur- 
face and  to  create  intense  itching,  which  lasts  for  1  wo  or  three  minutes 
after  the  cessation  of  the  treatment.  Masses  of  fat  fairly  melt  away 
under  this  treatment  and.  as  indicated  above,  the  application  can  be 
made  where  it  is  most  required.  In  some  cases  the  author  has  effected 
a  reduction  of  11  pounds  a  treatment,  three  times  a  week,  without  any 
other  exercise  and  with  onlv  ordinarv  care  about  diet.  Patients  who 


are  HinpK  In  I'm-  but  not  fat  are  not  apt  to  yield  much  in  weight  to  this 
1  n-at  incut .  and  perhap-  could  not  be  expected  to  do  so  without  a  bad 
effi-cl  ,  •  I  heir  general  health.  Hu'  even  these  mav  sometimes  be 
impro\  ,'.  A  man  .-  abdomen  or  a  woman  ,-  shoulders,  bu>t ,  or 

hi  p.-   n  ••'  i]  by  this  mean.-  ju.-t   as  by  the  more  natural  means 

of  outdoor  e\<-rcjv. 

I  In    I       «   <  >.  i  i  i  /it/*//'  in   (  /'n'-uiii/  <  '</M >.-    In  ^out.  rheumatism,  or 
in    .:.':-.    or      '  •     'a    the    many    conditions    likely    to   occur   in    men    and 
n    who  cut    und    drink   an   abundance  ol    rich    lood  and  wines,  and 
v/ho.  while  |"  loin.:;  plenty  of  menial  work,  ^ei    very  little  physi- 

cal ev-rci-1-.  ,  nt   i--  i,t'  the  Lrreate.-t   value.       It   nives  the  neces- 


HIGH-FREQUENCY    CURRENTS  605 

sary  stimulus  tu  digestion  and  circulation,  and  is  a  valuable  adjunct  to 
electric  treatment. 

(lout. — High-frequency  currents  applied  by  autoconduction  or 
autocondensation  —  or,  in  the  author's  practice,  especially  by  vacuum 
electrodes — give  excellent  results  in  this  disease.  Most  writer.-  do 
not  recommend  this  treatment  for  acute  attacks,  and  some  even  say 
that  it  may  precipitate  an  acute  attack.  The  author's  experience 
leads  him  to  believe,  however,  lliat  the  treatment  affords  relief  at  any 
stage  of  the  disease  and  that  any  case  may  be  treated  with  a  view  to 
producing  a  cure  after  a  complete  course  of  treatment.  If  the  auto- 
conduction  cage  or  the  autocondensation  couch  is  used,  the  current 
should  be  500  milliamperes  or  more,  and  the  application  should  last 
fifteen  minutes  and  be  given  three  times  a  week.  If  the  vacuum  elec- 
trodes are  used  they  should  be  exhausted  to  the  degree  which  will  give 
the  richest  lilac-colored  glow  and  the  greatest  amount  of  ultraviolet 
radiation,  as  detected  by  the  fluorescence  caused  in  a  piece  of  Willemite. 
The  current  should  be  about  200  milliamperes  from  either  the  d'Arson- 
val  transformer  or  the  Oudin  resonator  and  should  be  applied  over 
the  whole  of  the  affected  limb  for  fifteen  minutes,  keeping  the  electrode 
in  motion  and  avoiding  spark-effect.  The  current  should  be  reduced 
to  150  milliamperes  over  any  ec/ematous  areas  and  over  acutely  inflamed 
joints.  The  treatment  should  be  applied  three  times  a  week.  The  patient 
ought  to  feel  entirely  well  in  six  weeks,  but  to  consider  the  treatment 
finished,  two  or  three  courses  of  treatment  lasting  six  weeks  each  should  be 
ii'iven  separated  by  intervals  of  about  two  weeks.  The  tissue  oscillator  is 
applied  with  the  belt  around  the  hips  and  the  patient  facing  the  machine. 
A  mild  application  is  made  for  two  or  three  minutes.  In  this  disease. 
as  in  rheumatism,  the  effect  of  the  first  Treatment  is  often  wonderful. 
The  author  has  had  patients  who  expressed  doubt  as  to  its  being  due 
to  the  treatment  at  all.  They  said  it  must  have  been  a  coincidence, 
but  the  subsequent  course  of  events  convinced  them  that  it  was  the 
result  of  the  electric  applications.  After  the  first  treatment  the  im- 
provement is  no  longer  by  jumps,  but  is  gradual  and  uniform,  and  is 
much  more  rapid  than  in  rheumatism.  The  same  vacuum  electrodes 
completely  heal  the  chronic  or  subacute  ecxema  which  is  present  in  so 
many  of  these  cases.  This  is  accomplished  in  the  first  few  weeks. 

('.only  deposits  about  different  joints  are  often  removable  by  the 
high-frequency  application  called  thermopenetration  (page  031). 

.1.  \V.  Torbett1  treats  high  blood-pres>ure  (above  150)  without  a 
trace  of  sclerosis  by  hot  blanket  pack,  autocondensation,  or  electric- 
light  bath  cabinet,  both  followed  by  alternating  hot  and  cold  shower, 
cold  mitten  rub,  or  Scotch  douche  carefully  iriven. 

Arteriosclerosis. — Every  case  calls  for  an  .r-ray  examination  of  all 
the  teeth.  The  disease  is  often  caused  by  dental  infection  and  certainly 
will  not  yield  to  electric  treatment  until  the  infection  is  discovered  and 
cured.  The  application  of  high-frequency  currents,  especially  by  the 
autoconduction  cage,  has  a  marked  effect  in  reducing  functional  arterial 
hypertension.  This  effect  will  be  described  in  greater  detail  in  the 
paragraph  upon  neurasthenia  with  high  arterial  tension,  and  its  suc- 
cessful employment  in  that  disease  has  led  to  the  use  of  this  treatment 
in  arteriosclerosis.  In  the  early  stage-  of  this  disease  the  high  arterial 

1  AnuT.  Jour.  Ekvtrothcrupy  and  Hailiolo^v,  vol.  xxxvi.  No.  1,  January.  l*Mv 


()()()  MEDICAL    ELECTRICITY    AND    RONTUEN    HAYS 

tension  is  due  to  vasomotor  spasm  caused  by  the  same  auto-intoxication 
which,  acting  through  many  years,  is  likely  to  cause  structural  changes 
in  the  walls  of  vessels  and  in  every  organ  of  the  body.  The  auto- 
intoxication alluded  to  is  often  the  effect  of  a  sedentary  life,  with  or 
without  the  influence  of  alcohol,  and  is  especially  the  result  of  mental 
strain  in  business  or  professional  life.  It  develops  during  middle  or 
late  life,  and  is  a  condition  in  which  irritant  substances,  analogous 
to  those  in  uremia,  circulate  in  the  blood  and  produce  the  functional 
and.  finally,  the  increasing  structural  changes  referred  to.  Many 
of  the  ailment-  of  later  life—  rheumatic,  hepatic,  gastric,  and  nervous — 
are  the  natural  results  of  arteriosclerosis.  In  the  early  stages  this 
disease  can  probably  be  cured,  and  one  of  the  best  methods  of  treatment 
is  by  high-frequency  currents.  They  not  only  promptly  reduce  the 
blood-pressure  but  al-o  cure  the  condition  of  defective  metabolism  and 
elimination  which  is  the  cause  of  the  trouble.  During  the  treatment 
the  patient  may  be  completely  clothed  as  he  sits  inside  the  large  sole- 
noid, called  the  autoconduct ion  cage,  or  lies  upon  the  insulated  cushion 
ot  the  autocondensation  couch.  Hither  apparatus  is  connected  with  a 
d'. \rsonval  lu'uh-frequency  apparatus  actuated  by  an  .r-ray  coil,  a  trans- 
former, oi'  by  a  powerful  static  machine.  A  current  of  ">(!()  milliainperes 
or  more  passes  through  the  cage  or  the  couch,  the  patient,  with  the  cage, 
not  being  in  direct  connection  with  the  apparatus  at  all.  but  receiving  an 
electric  induction.  The  electric  effect  upon  the  patient  is  analogous  to 
the  induction  of  a  powerful  current  in  a  secondary  coil  bv  the  passage 
of  a  current  through  a  primary  coil  with  which  it  is  nowhere  in  contact 
and  from  which,  in  fact,  it  i-  most  carefully  insulated.  The  applications 
la-t  fifteen  minutes  and  should  be  given  every  other  day  for  about  three 
weeks.  In  an  early  staue  of  arteriosclerosis  each  treatment  may  be  fol- 
lowed  by  a  fall  in  arterial  pressure  amounting  to  2(1  or  more  millimeters 
of  mercury.  Before  the  next  treatment  the  pressure  rises  ana  in,  but 
not  to  its  original  level,  and  gradually  the  normal  level  is  r<  ached  and 
maintained.  In  advanced  eases  of  arteriosclerosis  this  treatment  is 
al-=d  to  be  recommended,  and  the  author's  experience  with  it  has  in- 
cluded  ca-es  in  which  -Mine  one  effect  such  a-  rheumatism,  neuras- 
•'.  embnhis.  or  hcmianopsia-  has  required  treatment.  Hlectric- 
hnht  baths  also  li'ive  excellent  results  in  arteriosclerosis. 

Autocondensation  with  a  thick  dielectric  and  small  amperage  are 
considered  by  \V.  T.  Johnson'  to  give  better  therapeutic  effects.  lie 
te-  Dr.  Mat  hew  Steel's  report  of  a  fall  in  blood-pressure  of  4  to  10 
.  and  an  increase  in  pulse-rate  of  2  to  S  in  a  normal  man,  and  an  in- 
crease  ,,f  :;iil)  c.e,  in  the  volume  of  urine  and  an  increase  of  .")  or  10  grams 
in  the  daily  urinary  solids.  And  the  autocondensation  with  a  thin 
dii  >  ctrie.  while  producing  a  sensation  of  warmth  and  also  excessive  per- 
s  pi  rat  ion,  reduces  the  volume'  of  urine,  increase-  t  he  urinary  solids  about 
2  irram-,  and  lia-  little  effect  upon  the  blood-pressure. 

' //    in    'in.   nn.     A.  L.  ( lordon,- treats  early  cases  by  diathermy 
I'd  i-u-hion  on  a  couch  and  KM)  to  ")()()  ma.  for  fifteen  or  twenty 

and   later  every  other  day.      Inactivity  of  the  liver  is 
t  he  static  wave  current .  larne  metal  elect  rode  to  lower  mar- 

:   a-    -iron"   a   current    a-   patient    \vill  take  for  fifteen  or 

'.  r'..   M.  -1    .1     n 

ml   K:nli<>loiry.  vol.  \\xvi.  X<,.   1.  .I;iiiu:irv.  191S, 


HIGH-FREQUENCY    (TRKKNT.S 


607 


twenty  minutes;  or  by  the  slow  sinusoidal  current  with  one  lar<ie  pad 
over  the  lower  border  of  the  liver  and  another  at  the  back,  as  strong  as  he 
will  stand  for  fifteen  or  twenty  minutes.  Constipation  is  most  ef- 
fectively treated  by  slow  sinusoidal  lar^e  pad  over  abdomen  and  back. 

High-frequency  Currents  in  Diseases  of  the  Lungs.-  flrmirju'tix 
nnd  iixtlnnn  may  be  relieved  by  the  application  of  high-frequency 
currents  to  the  chest-wall,  preferably  using  a  vacuum  electrode 
with  a  current  of  l.">0  milliamperes,  although  the  "French  writer-  use 
the  effiuve  with  some  direct  sparks.  In  either  way  a  revulsive  and 
tonic  effect  is  obtained  which  would  certainly  be  of  benefit  in  these 
oases. 

Tuberculosis  is  certainly  susceptible  of  wonderful  benefit  by  hiirh- 
frequency  currents,  but  as  with  every  other  form  of  treatment,  some 


mercury  vapor  lijrht,  and  mali-frcqucncy  currents. 


eases  iret  only  moderately  well  and  eventually  die  of  the  disease.  Other 
cases  apparently  net  entirely  well  and  may  or  may  not  have  a  return  of 
the  trouble  at  some  future  time.  And  in  these  cases  who  can  say  just 
what  role  the  treatment  has  played  in  the  process  of  recovery?  The 
author'.-  own  technic  in  these  cases  include-  the  use  of  t  he  .r-ray  and  t  he 
mercury  vapor  electric  ligh.1  besides  the  hi<rh-frequency  currents.  But  it 
is  interest  n m'  to  note  that  do/ ens  of  apparently  complete  cures  have  been 
reported  by  means  of  hi«;h -frequency  current-  alone  (I)oumer.  (landil. 
Oudin,  A\  ilhams,  Bowie,  etc.).  The  method  employed  has  usually 
been  by  the  ,-IIluve  from  an  Oudin  resonator  applied  over  the  chest  for 
five  or  ten  minutes  dailv.  especially  to  the  supraclavicular  regions. 
Tlie  strongest  possible  discharge  was  used  and  a  certain  number  of 

to    pass    tn    the   surface   of   the   bodv.      The 


t)l)S  MKDICAL    KLKCTKICITY    AND    HONTdKN     HAYS 

sequence  of  events  has  been  improvement  in  the  general  health,  dis- 
appearance or  reduction  in  the  number  of  bacilli,  diminution  in  cough 
anil  expectoration,  and,  finally,  improvement  in  physical  siirns. 

An  instructive  case  in  the  author's  practice  was  that  of  a  young 
woman  with  tulxTculosis  of  the  lungs  and  larynx.  The  throat  specialist 
could  see  an  ulceration  below  the  true  vocal  cords.  She  had  no  voice 
at  all  and  was  unable  to  swallow  anything  but  liquids.  The  expec- 
toration wa-  -o  profuse  as  to  choke  her  and  it  was  full  of  tubercle  bacilli. 
Treat  men  t  was  begun  in  December,  1903,  and  consisted  in  1  he  application 
of  the  .r-ray,  the  mercury  vapor  light,  and  high-frequency  currents. 
The  ./'-ray  was  used  once  in  live  days,  the  anticathode  ot  the  Tube  being 
15  inches  from  the  nearest  surface  of  the  chest  and  the  time  of  exposure 
four  minutes  in  front  and  four  minutes  behind  the  chest.  A  10-cm. 
heavy  anode  (lundlach  tube  was  used  and  an  s-mch  Ruhmkorfl  coil 
with  a  Caldwell-Simon  interrupter.  The  rays  were  about  Xo.  1  of  the 
Walter  or  Benoist  scales  and  the  current  passing  through  the  primary 
•  •oil  was  about  I  amperes.  Immediately  after  this  application  a  Morton 
treatment  tube  similar  To  the  author's  special  .r-ray  Tube,  described 
under  the  treatment  of  diseases  of  the  mouth  by  high-frequency  cur- 
rents, was  applied  To  the  outside  of  the  larynx.  The  extremity  of 
the  tube  was  in  com  act  with  the  skin  and  a  total  exposure  of  two  minutes 
was  made  over  different  aspects  of  the  larynx.  Xo  other  treatment  was 
applied  on  these  days.  Between  each  two  .r-ray  treatments  a  treatment 
by  the  mercury  vapor  light  and  high-frequency  currents  was  given.  The 
Cooper  Hewitt  lamp.  100-candlepower.  was  placed  within  o  inches  of 
the  bare  chest  for  ten  minutes  in  front  and  ten  minutes  behind.  This 
mad-'  the  skin  feel  hot  to  the  touch,  but  occasioned  no  redness  or 
perspiration.  The  lamp  was  so  arranged  That  the  patient's  eyes  were 
shielded  from  the  light.  Immediately  after  this  a  glass  vacuum  elec- 
trode was  applied  all  over  the  chest  and  neck.  The  electrode  was  con- 
nected directly  with  one  pole  of  the  .r-ray  coil,  about  .'>  amperes  of  pri- 
mary current  were  used,  and  care  was  taken  To  have  a  good  contact 
and  avoid  a  spark-effect.  The  result  was  extremely  encouraging.  In 
t hree  weeks  her  voice  became  good  enough  to  Talk  over  the  telephone  and 
the  ex  pectoral  ion  ceased.  In  t  hree  months  t  he  t  hroat  specialist  reported 
that  nothing  remained  of  the  ulcer,  but  in  its  place  there  was  a  white 
>i  ciratrix.  She  was  able  to  eat  everything  and  had  gained  -1  or  "> 
eight.  1  his  was  the  condition  of  things  when  the  progress 
a-e  was  reported  at  a  meetiim  ot  the  Medical  Association 
of  New  York.  March.  Idol.  She  continued  to 
'.Mil.  when  the  treatment  was  stopped  on  account 
)  u  rim:  the  following  winter  t  here  was  a  gradual 
ion.  but  she  did  not  again  conn-  under  .r-rav 
did  1  >et  ter  while  under 
i  it  herwise  and  in  ml  it 
•n  cotit  mued. 
1  >a  rnu n i1  bv  the  use  oi 
li  i'^h-t  rei  ii;ency  currents  from 
pa  rt  of  the  t  i  eat  meni  consist  - 
i L;  chair  or  couch  \\hich  is  m  circuit 
ion  i-  made  with  the  patient 
•-cnl  >es  the  effect  s  as  an  imme- 
AuL'U-t.  I'tK.'i. 


HKJH-FRKQUKXCY    CURRENTS  00'.) 

diate  rise  of  temperature  of  at  least  1°  I-',  during  the  time  of  treatment 
and  a  sense  of  exhilarat  ion  last  ing  for  twenty-four  to  sevent  v-t  \vo  hours. 
He  uses  an  unusally  po\vei1'ul  high-frequency  apparatus  consisting  oi' 
very  large  beyden  jars  and  an  Oudin  resonatoi1.  \'2  inches  in  diameter 
ami  '.]  feet  high,  and  regularly  applies  from  2000  to  :>000  milliamperes. 
Some  ot  his  cases  were  apparently  cured.  The  treatment  \vas  carried 
on  in  connection  with  tent-life  in  Los  Angeles,  California. 

High-frequency  Currents  in  Diseases  of  the  Larynx.—  -Tnlx-r- 
cidoxix  of  the  lari/n.r  is  a  disease  in  which  high-frequency  currents  and 
the  .r-ray  afford  relief  with  a  possibility  of  cure.  The  method  of  appli- 
cation lias  been  described  in  the  preceding  paragraph.-. 

Cancer  of  the  larynx  is  favorablv  influenced  I>v  high-frequency 
currents  in  conjunction  with  the  r-ray  applied  in  the  same  way  as  for 
tuberculosis.  In  a  general  way  the  effect  of  the  ./--ray  is  alterative: 
that  ot  the  high-frequency  current  eliminat  ive.  The  x-ray  causes 
molecular  death  of  a  neoplasm  and  high-frequency  currents  cause  the 
rapid  removal  of  the  waste  products. 

Chronic  Laryngitis. — Here  the  indication  is  for  the  vacuum  electrode 
or  the  effluve  over  the  outer  surface  of  tin 
t  rode  of  ball   shape  should  be  used  which   w 
even  with  the  electrode  in  good  contact    witl 
should  !;-;•  I'bout   100  milliamperes. 

High-frequency  Current*  in  Dixcaxt:*  of  tin  Stomach  and  Intextincs  — 
Aton a  of  thi  Stomac/i  vith  or  irf  thoi.it  dilatation  is  promptly  and  favor- 
ably influenced  by  high-frequency  current.-.  Such  a  case  was  that  of 
a  retired  naval  officer  who  was  invalided  home  from  t  he  Philippines 
during  the  Spanish-American  AVar  with  the  nervous  breakdown  which 
affected  so  many  of  our  officers  there.  In  his  case  the  trouble  was 
chiefly  gastric,  and  all  t  he-e  seven  years  or  so  he  had  suffered  from  mom- 
mi;  vomiting  and  abdominal  pain.  These  symptoms  had  become  worse 
of  late,  and  when  he  came  for  electric  treatment  lie  was  unable1  to  keep 
anything  on  his  stomach,  and  the  question  arose  as  to  whether  any 
malignant  trouble  was  developing.  After  a  test-meal  an  examination 
was  made  by  the  late  Dr.  Kemp,  the  gastro-intestinal  specialist.  lie 
found  that  the  stomach  extended  to  2  inches  above  the  umbilicus  and 
that ,  therefore,  there  was  no  dilatation.  Atony  was  evidenced  by  marked 
splashing.  Free  hydrochloric  acid,  L'O;  combined  hydrochloric  acid, 
o">;  total  acidity,  00.  Some  lactic-acid  fermentation.  The  patient 
was  placed  upon  the  usual  medicinal  treatment  for  such  a  condition: 
resorcin,  hydrochloric  acid,  mix  vomica,  and  cinchona;  and  peptonoids 
in  place  of  his  customary  whisky.  The  electric  treatment  consisted 
in  the  application  of  a  vacuum  electrode  over  the  stomach  and  adja- 
cent regions  for  ten  minutes  with  a  current  of  loO  amperes  and  without 
spark-effect;  this  being  followed  by  the  same  application  along  both 
sides  of  the  spine  from  the  upper  to  the  lower  limits  of  the  scapula. 
In  this  region  some  spark-effec.  was  cautiously  applied.  It  had  to  be 
slight'  because  of  the  tendency  of  the  skin  to  become  covered  with  inu- 
red >pots.  The  high-frequency  currents  were  begun  about  seven  or 
eight  days  before  it  was  convenient  for  him  to  begin  taking  the  medicine. 
Improvement  began  immediately  and  lie  did  not  have  a  single  attack 
of  vomiting  after  tin?  electric  treatment  was  begun.  During  the  course 
of  the  treatment,  which  lasted  two  months,  he  did  not  have  a  single 
one  of  the  frequent  attacks  of  vomiting  and  pain  which  used  to  incapaci- 


MKIHCAL    ELECTRICITY    AND    RONTGKN    RAYS 

late  him  for  a  day  at  frequent  intervals.  Quite  early  in  the  treatment 
he  was  rejoiced  to  find  that  he  could  brush  his  teeth  before  breakfast 
without  being  nauseated.  He  was  apparently  entirely  cured  at  the 
end  of  the  course  of  treatment. 

Constipation  may  often  be  cured  by  treatment  with  high-frequency 
currents,  as  in  the  ca.-e  of  a  young  lady  who  had  been  operated  on  for 
hemorrhoids.  The  constipation  which  originally  brought  on  the  trouble, 
was  nut  relieved  by  the  operation  and  did  not  yield  to  ordinary  medic- 
inal treatment.  The  electric  treatment  was  given  by  means  of  a 
glass  vacuum  electrode  whose  conducting  cord  was  connected  directly 
with  one  pole  of  an  .r-ray  coil.  A  primary  current  of  about  3  amperes 
was  used  with  a  Caldwell-Simon  interrupter.  The  electrode  was  passed 
all  over  the  abdomen  and  some  contraction  was  visible  as  first  one  and 
then  another  muscular  mass  was  influenced  hy  the  current,  (liven 
in  thi-  way  it  is  desirable  to  avoid  a  spark-effect,  and  if  a  strong  current 
is  used  derided  muscular  contractions  may  be  produced.  The  result 
of  a  fe\v  weeks'  treatment  was  a  cure  which  has  continued  for  the  two 
year-  which  have  elapsed  since  that  time.  Similar  results  have  been  re- 
ported hy  l-'leig  and  Friinkel.1  High-frequency  currents  are  so  easily 
applied  and  with  the  proper  equipment  so  readily  measured  and  con- 
trolled that  they  may  occasionally  be  tried  in  a  case  in  which  the  com- 
bined galvanic  and  faradic  current  might  possibly  he  better.  Noth- 
ing hut  benefit  is  to  be  expected  from  the'  high-frequency  currents, 
however,  and  if  they  are  not  effective  a  change1  may  be  made  to  the 
other  form. 

A  certain  number  of  cases  depend  upon  a  spastic  condition  of  the 
sphincter  ani.  and  for  these  a  rectal  vacuum  electrode  from  either  the 


d'Ar.Minval  transformer  or  the  lower  polo  of  the  Ondin  resonator  Is  held 
in  the  rectum  while  a  current  of  150  milliamperes  is  allowed  to  How 
through  it  lor  three,  four,  or  five  minutes.  It  is  necessary  to  stop 
occasionally  to  allow  the  electrode  to  cool  off.  Suitable  electrodes  are 
1 '  wit  h  all  insulatei  1  stem. 

. —  High-frequency    currents    are    ahno-t     a    specific    in    this 

ihe  first    report   to  be  made  upon   the  subject   was  bv  the 

']',     ami   .-nice  that    time  he   has   treated   many  cases,   of 

y  Jx-  cited  as  examples.     One  patient  was  a  large,  strong 

""oi  •  had  >uffered  ironi  coin  is  for  four  years  in  spite  of 

eatmenl    by   her  brother  who  has  for  many  years  been  a 

'  '  '•'    1-oard  of  Health  physician.     The  trouble  was  always  worse 

.'    ".  <  '.'.  and  during  the  summer  of  J'.KKi  it  had  assumed  a  dvsen- 

She  had   twentv-five   bloodv   movements  a   dav  for  a 

'!:,«    medicine,  whatever  it    may  have  been   before-,  was 

and   catechu,   and   an   electric   treatment   was  given 

1     •      ni£.     She  pa»ed  a  comfortable  night  and  the  following 

riicr;i))cuti(|Uc  I'liy-inur;  Arch,  of  tin-  Hont^rii  K.-iy,  June, 
ti.-.  N'cu  York  Medical  .Journal.  .July  1  1 ,  I'.tli:-;. 


HIGH-FREQUENCY    CURRENTS  611 

day  had  only  one  movement.  Ten  treatments  were  given  during  the 
next  throe  weeks  and  resulted  in  an  entire  cure,  from  which  there  has 
been  no  relapse  during  the  four  years  that  have  ensued.  The  treatment 
employed  in  this  case  was  a  combination  of  the  x-ray  and  vibratory 
currents.  A  tube  of  moderately  high  penetration  was  used,  rays  about 
No.  0  Benoist,  with  the  anticathode  at  a  distance  of  about  12  inches 
from  the  bare  surface  of  the  abdomen.  An  S-inch  Ruhmkorf'f  coil 
was  used  with  a  Calchvoll-Simon  interrupter,  a  primary  current  of  about 
3  amperes,  and  an  exposure  of  four  or  five  minutes.  This  was  followed 
by  the  application  of  a  glass  vacuum  electrode  all  over  the  surface  of 
the  abdomen,  but  especially  over  two  or  three  painful  spots.  The 
conducting  cord  was  attached  directly  to  one  pole  of  the  a>ray  coil. 
As  little  spark-effect  was  produced  as  possible. 

The  other  case  is  typic  of  a  more  numerous  class.  The  patient  is  of 
a  highly  neurotic  type  and  has  had  many  tilings  to  worry  and  excite  her. 
Before  coming  under  treatment  she  had  for  a  number  of  years  been 
almost  daily  passing  a  largo  gelatinous  mass,  which  looked  as  if  it  could 
be  straightened  out  into  a  thick  cord  or  ribbon  or  tube  many  yards  in 
length.  It  looked  like  some  new  and  strange  kind  of  worm.  As  the 
patient  had  a  marked  family  history  of  tuberculosis  a  pathologic  exami- 
nation was  made,  the  report  being  that  the  discharge  contained  essen- 
tially mucus  and  granular  epithelial  detritus.  There  was  always  severe 
abdominal  pain  preceding  these  movements.  Reliance  was  placed  upon 
the  .r-ray  and  a  vibratory  current  given  in  the  same  way  as  for  the  other 
case.  A  cure  was  promptly  brought  about  and  for  the  last  two  or 
three  years  there  has  been  no  tendency  to  a  permanent  return  of  the 
trouble.  When  she  gets  terribly  excited,  however,  there  are  attacks 
of  the  same  nature  lasting  for  one  or  two  days.  If  she  is  in  the  city 
and  receives  a  treatment  the  pain  is  immediately  relieved  and  the 
attack  brought  to  an  end.  The  subsequent  occasional  single  treatments 
have  been  by  vibratory  currents  alone  through  the  vacuum  electrode, 
The  benefit  produced  in  these  cases  is  due  as  elsewhere  to  what  can  only 
be  termed  the  intense  vitalizing  action  of  this  current,  not  to  any  direct 
bactericidal  effect. 

L'ttlnrrhal  Appendicitis. — A  certain  number  of  chronic  cases  in  which 
this  seems  to  be  the  condition  are  permanently  cured  by  the  same 
technic  that  is  so  effective  in  colitis.  This  has  been  used  by  the 
author  not  with  a  view  to  the  avoidance  of  a  surgical  operation  where 
that  was  indicated,  but  as  the  best  method  of  treatment  where  an 
operation  is  not  required  or  when  it  has  been  performed  and  there  are 
still  adhesions  mid  infiltrations  to  b<  eliminated.  JKxcellent  results 
have  been  obtained  when  the  vacuum  electrode  from  the  Oudm  resona- 
tor is  applied  over  all  the  affected  portion  ot  the  abdomen  for  about 
twelve  minutes' with  a  current  of  loo  to  '-'no  niilliamperes.  A  good 
contact  is  desirable  and  the  electrode  should  be  in  constant  motion. 
High-frequency  Currents  in  Diseases  of  the  Rectum. — Doumer. 
in  1  V»7,'  was  t  he  first  to  publi-h  any  larire  number  of  rectal  cases  1  reated 
by  high-frequeiiey  currents,  and  his  success  was  quickly  corroborated 
by  the  reports  of  Sudnik.-  Stembo.:i  Tschdanow."1  and  more  recently 

1   \nn.  .rKlcM'trnhiolnuMf. 

-  [hiil.,  ivt'.i. 

:;  Dontra.  Mc<l.  Woch.,  No.  ^  1<»<V_>. 

Miotkin's  Hospital  Zciluni:.  N~o.  •"•().   15)00. 


012  MKDICAL    KLl-XTKK  ITY    AND    K(")NTCKN     HAYS 

by  Bilinkin1  aiul  Marque-.-  Hundreds  of  cases  have  been  reported 
altogether  and  fairlv  accurate*  conclusions  may  be  drawn  from  them. 
I*' is*  it  re  of  tin  «/////>•  is  in  about  one-half  the  cases  cured  by  from  three* 
to  nine  applications  and  there  is  prompt  disappearance  of  the  accom- 
panying spasm  of  the  sphincter.  Other  cases  require  many  more 
treatments  and  some  do  not  get  well  till  the  sphincter  is  stretched. 
//,  'tiorrhn'nl*.  Simple  vascular  masses  of  recent  development  show 
about  .")ii  per  cent,  of  complete  cures  and  decided  benefit  in  almost  all 
the  others.  The  number  of  applications  is  from  four  to  eleven.  Inter- 
nal and  external  vascular  masses  with  occasional  acute  exacerbations, 
bin  without  hype-rtrophic  changes,  are  almost  alwavs  greatly  benefited 
and  one-third  of  the  cases  are  completely  cured. 

In  all  the  above  cases  the  accompanying  constipation  is  usually 
cured  at  the  same  time  as  the  local  lesion. 

I 'lii'nii if  Ht'Hini'i'himix  ii'it/i    I  Ini'kt  iniii/  urn',   Irntdhiltti/  nj  tlic  Folilx  <>J 
>      •  .    '/<//     11  ///unit    Mu /•/,•<  <l    \'<  nniix    ('o)Hji'stinn.—   .\<me    ot    these    cases 
•  been  entirely  cured,,  but  all  are  improved  in  seven  to  fifteen  treat- 
ments, and  ")()  per  cent,  are  very  greatlv  benefited. 

1. iii-ili  Vtmntx  Hi  nini'i'finidiil  Mtissis.  K.rh  run!  mi<l  I titiDtiil .  —  Bilin- 
kin treateel  Itl  cases,  irivinii'  twelve  to  thirty  applications,  with  amelio- 
ration in  7  cases  and  failure  in  !)  cases.  Two  of  these'  1(1  cases  were1 
recurrences  after  operation  and  almost  all  were  lonu'-standing  cases 
complicated  bv  chronic  Castro-intestinal  disorders.  In  such  case's 
electricity  applied  locallv  does  not  give  be'tter  results  than  other  non- 
operative  forms  of  treatment.  Success  could  doubtles-  be  obtained, 
however,  bv  a  long  course  oi  treatment  in  which,  according  to  my  own 
vie-  .  the'  local  treatment  should  be  supplemented  by  the  application 
ot  liiuh-t'requi  ncy  currents,  the  galvanotaradic  cnri'ent,  or  the  sinusoidal 
furrein  over  the  abdomen  and  perhap.-  to  the  corresponding  spinal 
centers.  The  treat  me-nt  t  hu>  directed  to  t  he  cause  of  the  t  rouble  would 
be  «\  the'  greatest  value  also  m  cases  which  we're  operated  upon  and 

.'    be  used  either  before  or  after  the  operation. 

/',, .•,,-,,•.'  ,  l/cmnri-lioiilx  (J'rolitjixi  irilli  1 ! ', ,//,-//,  ssn/tlu  S/>lu'iicti  r]  .— 
liiliukin  treated  (i  cases,  eight  to  nineteen  applications,  -1  were  cured, 
'_'  much  improved;  m  everv  case  the  general  tunic  effect  was  verv  great. 
i  in  'I  i-ii  i  ni  1,-nl  ni/is  to  II  ii//i-/'/'n/u<  nrij  Currint*  in  lit  nioriiiotda. — 
I'ln  had  re-tilts  in  exi-eptional  cases  are  an  increase  in  swelling,  con- 
r-ldi-i  •  '  .  ;il)il  -nine  lieliiorrhage ;  in  others  all  acute  exacerbation 

"I    the'    condr  lein.      \\heii    this    takes    jilace    this    line   of    t  re-at  ine-nt    had 
bel  tep  be  a  1  .a  1  idolied  .;; 

I  In  rtmifu  tn  triitniH  /x  a  nn  lln>tl  nl  //'in// ni/  h<n/»/'/'!ini(/x,  \\~hich  is  con- 
-idi'i'ed  tin  -eparnte  .-ertion  eleveited  to  that  form  of  high-fre([Uency 
application. 

//'/  .    Truth rlhij  Hifih-frcf/iHiicii  I)(xi(T<it/on.-    \\'m.  I..  Clark4 

il-i--   the    ctiri'etil    from   an  (  )ndin   resonator.      An  ordinarv  steel   needle' 

i-  u-ed  le»  apply  the  high-frequency  current  directly  to  the  h(vmorrhoid, 

^'d    at    its   base.      The   current    is   no!    stmnu'  enough    to 

le  .    but    merely    t"   coaiiulate   and    de>iccate    them.      The 

liemorrhnid   i-  cut   off  \\ith   the  scissors  close  to  the  clamp. 


HKill-FKKQrKNCY    CL'UKENTS 

Pruritus  Ant  trith  3foi*t  Eczcnui. —  Bilinkin  treated  lo  cases,  ioui 
to  seven  applications,  \vith  a  cure  in  ('very  case.  The  present  author, 
however,  has  encountered  certain  cases  of  pruritus  ani  which  would 
not  yield  to  this  or  any  other  form  of  treatment,  operative  or  non- 
operative.  local  or  general,  except  the  .r-ray,  which  seems  to  be  a 
specific.  There  is  nothing  magic  about  the  high-frequency  current.-, 
though  they  are  very  effective  in  most  cases  of  rectal  disease. 

Pnralysu,  of  the  Sphincter  An!.- — The  most  difficult  cases  to  cure 
are  those  resulting  from  overstretching  in  the  operation  for  hemorrhoids 
or  fissure.  One  such  patient  who  was  treated  by  the  author  had  been 
operated  on  for  ulcers  of  the  rectum  by  one  of  the  foremost  rectal 
surgeons.  The  cast1  had  been  one  of  spasmodic  stricture  of  the  urethra 
or  spasm  of  the  sphincter  vesiea-.  and  the  patient,  a  man  under  forty, 
had  frequently  been  entirely  unable  to  urinate.  After  waiting  a  few 
hours  he  could  do  so.  A  stricture  of  large  caliber  was  diagnosed  and  he 
was  operated  on.  There1  was  temporary  relief  from  the  retention  of 
urine,  but  on  the  return  of  the  trouble  the  ulcers  in  the  rectum  were 
discovered  and  were  regarded  as  having  in  a  reflex  way  produced  the 
difficulty  of  micturition.  The  operation  had  consisted  in  stretching 
the  sphincter  ani  and  applying  a  Paquelin  thermocautery  to  the  ulcer- 
ated surface.  This  was  of  temporary  benefit  as  far  as  urination  was  con- 
cerned, but  it  resulted  in  a  relaxed  condition  of  the  anus  and  paralysis 
of  the  sphincter.  For  two  whole  years  the  patient  had  to  wear  a  sort, 
of  plug  made  of  cotton  and  on  many  different  occasions  soiled  his 
underwear  through  his  inability  to  restrain  a  movement  for  a  minute 
after  the  desire  was  felt.  He  had  to  regulate  his  diet  so  as  to  avoid 
soft  movements,  which  were  especially  liable  to  cause  trouble.  Then- 
was  a  return  of  the  difficulty  of  micturition  and  a  development  of  abso- 
lute impotence,  no  erectile  power  remaining  at  all.  A  Xo.  o(i  (French) 
sound  could  be  passed  into  the  bladder.  There  was  a  certain  amount 
of  ulceration  in  the  rectum.  Treatment  consisted  in  the  occasional 
passage  of  a  Xo.  )•>()  sound  and  the  application  of  high-frequency  currents 
in  the  rectum,  over  the  genitals,  and  along  the  spine.  About  fifteen 
treatments  were  iriven.  The  impotence  was  cured  and  his  wife  became 
preirnant.  The  anus  lost  its  relaxed  look  and  he  ceased  to  be  troubled 
by  incontinence  of  feces,  although  the  sphincter  did  not  regain  its  full 
power.  He  became  able  to  urinate  whenever  he  wished  to.  The  rectal 
ulcers  healed.  From  this  condition  then1  has  been  very  little  back- 
sliding during  the  year  that  has  elapsed  since  the  course  of  treatment 
was  finished. 

I-'tx/uln  has  been  reported  by  Doumer  as  cured  by  high-frequency 
currents,  in  several  different  patients,  and  the  method  is  certainly 
wort  h  a  t  rial  when  an  operation  is  undesirable  for  any  reason.  The  cases 
in  which  it  is  most  likely  to  be  successful  are  those  in  which  there  is 
no  apparent  reason  why  the  sinus  will  not  heal, 
sive  undermining  and  multiple  tracts  are  not 
high-frequency  currents  as  a  resolvent  would  be  a  valuable  adjunct  to 
surgery. 

i'li'rr  and  stricture  of  the  'rectum  are  benefited  by  high-frequency 
currents,  but  perhaps  not  as  much  as  by  the  galvanic  current,  with  or 
without  copper  elect  roivsis. 

A  glass  vacuum  electrode  with  an  insulated  stem  of  the  type  illus- 
trated on  pau;e  5S1  is  introduced  into  the  rectum  and  its  tip  pressed 


tilt  MEDICAL    KLKCTKICITY    AND    KONTCKN    RAYS 

into  the   narrowed   lumen.     A   current    of   1">0  milliamperes  from  the 

Oudin  or  the  d'Arsonval  is  applied  for  ten  minutes  every  other  day. 
The  current  should  he  turned  off  tit  intervals  to  allow  the  tube  to  cool. 
A  successful  case  has  been  reported  by  Crane.1  in  which  the  trouble 
appeared  to  be  cancerous.  He  concludes  that  it  was  not  malignant 
because  it  yielded  completely  to  the  treatment. 

The  nntlinil  of  a i>jili<-iitii)/i  in  till  these  rectal  diseases  may  be  by  a 
metallic  rectal  electrode  connected  with  a  d ' Arson val  transformer  and  a 
verv  hetivv  current  :  o(H)  to  4.">()  milliamperes  may  be  applied  without  tiny 
sen -at  ion  except  of  m  i  Id  warmth ;  or  a  id  ass  vacuum  electrode  connected 
with  the  upper  pole  of  an  <  )udin  resonator  may  be  used.  It  is  desirable 
that  this  should  have  an  insulated  stem  and  that  it  should  be  exhausted 
to  quite  a  hiirh  degree  of  vacuum.  This  means  a  higher  degree  of 
vacuum  than  is  present  when  the  tube  gives  a  rich  lavender  colored 
liirht.  the  li-ht  being,  on  the  contrary,  a  ste<  1  blue  or  gray.  And  when 
the  current  is  turned  in  the  right  direction,  so  that  with  the  d'Arsonval 
transformer  the  u'lass  electrode  connected  with  what  ma}"  be  termed 
the  cttthodal  or  negative  pole  of  the  coil  a  decided  admixture  of  the 
yellowish  green  ( indicating  the  impact  of  cathode  rays  and  giving  origin 
to  .r-rays)  is  visible;.  As  a  rule,  vacuum  electrodes  are  used  only  with 
Tesla  and  <  hidin  currents  and  metal  elect  rodes  with  d  'Arsonval  currents. 
According  to  Bilinkin.  the  latter  is  more  agreeable  to  the  patient  and  more 
effective.  The  shape  of  the  electrodes,  whether  conic  or  practically 
cylindric,  is  not  important.  They  should  be  of  such  a  size  and  shape 
that  they  can  be  introduced  readily  and  that  they  will  make  a  good 
contact  with  the  entire  mucous  membrane  of  the  part  of  the  rectum 
in  uhi'-h  they  are  placed.  \Yhen  vacuum  electrodes  tire  used  the 
current  ought  to  be  1'J")  to  !">()  milliamperes  and  the  time  of  application 
from  five  to  fifteen  minutes.  The  electrode  is  not  moved  about,  but 
it  i-  necessary  to  stop  several  times  to  prevent  it  from  getting  uncom- 
fortably hot.  With  a  metallic  electrode  the  current  may  be  stronger 
'_'IID  to  l.")i)  milliamperes)  and  the  time  of  application  is  about  the 
same.  The  author's  special  handle  (Fig.3(i3,  page  .~i.~>(.h  for  the  vacuum 
eli  ctrodes.  i-  completelv  insulated,  the  metal  socket  into  which  the  glass 
electrode  screws  bein-j;  protected  by  tin  extension  of  the  hard-rubber 
handle  1  inch  beyond  the  metal.  The  patient  cannot  receive  a  current 
iroin  contact  with  anv  part  of  the  appliance  except  the  glass  electrode. 
-  more  neci-.--.arv  in  the  case  of  the  different  cavities  of  the  body 
than  when  applvmg  the  electrode.-  to  ,-ome  convex  surface,  but  when 

-    :.<'".'.    disagreeable   the  .-park.-   troin   anv  exposed   metallic 

itindle  would  be,  it   is  easy  to  see  why  the  fully  protected 

I'  Trei  1  in  pract  icallv  all  cases. 

lit    may  be  (  1  j   in  a  dor-a!  posit  ion  with  the  t  highs  veil  ical 
oiled    bv   crutches   attached    to   the    table   at     1'J   to    11 
it-  level;  or  <'_')  he  may  lie  upon  his  side  in  the  Sims  gyne- 

lon;  or   i-'i)   he  mav  he  upon   his  back  with   legs  and  thighs 
ro.-sed.    and    knees    far   apart.      The    (n-t    position    is 
n  '1  unless  there  i-  some  reason  lor  not   u.-ing  it.      Jt 
I'ecium.  buttocks,  ihighs.  and  genital  and  hypogastric 
the    regular   operating    or   examining    tables    may    be 
iper   crutches    for    this    po.-ition.      The   ordinary 

iched    '''     i    Lrynecologic    table   are    unsatisfactory    for   elec- 
h.rt  V.    vn<    Mc,!ic;tl  .Journal  M:ijr:i/inc,  Man-li.  l!»o:,. 


HIGH-FREQUENCY    CURRENTS 


01") 


trothcrapy  about  the  rectum.  The  position  they  jnve  is  an  extremely 
uncomfortable  one,  which  no  patient  should  be  compelled  to  endure 
for  a  quarter  of  an  hour,  and  the  anus  is  not  brought  into  view,  but 
is  down  close  to  the  table.  One  reason  why  the  first  position  miirht 
not  be  selected  in  any  individual  case  is  that  the  operator  inijiht  not 
have  a  table  with  the  proper  crutches.  Another  reason  nii<i'ht  be  that 
the  patient  is  a  youn<i  woman  requiring  only  a  rectal  application  and 
the  Sims  position  would  be  preferable  because  of  the  less  exposure. 

It  is  important  when  usinji'  a  unipolar  electrode  connected  directly 
with  one  pole  of  the  .r-ray  coil  to  prevent  contact  between  the  patient 
and  any  metallic  parts  of  the  table.  The  top  of  the  crutches  may  be 
protected  by  throwing  a  folded  piece  of  rubber  sheeting  over  them. 

High-frequency  Currents  in  Diseases  of  the  Mouth. — /sVY/f/* ' 
l)ixc(ix( .  or  I\i/orrlic(i  Ali'cola'rix.—  This  is  a  disease  which  is  often  fatal 


f  pyorrhoa  alvcolaris. 


to  the  tooth  which  it  attacks.  The  symptom-  are  pain  and  tenderness 
and  sensitiveness  to  heat  and  cold.  An  Knirlish  medical  man  who 
suffered  from  it  said  that  he  had  to  warm  his  beer  and  cool  his  tea. 
The  u'um  about  the  affected  tooth  is  red  and  swollen  and  may  be  ulcer- 
ated. It-  margin  is  separated  from  the  tooth  and  a  pocket  is  produced 
in  which  black  concretions  are  often  found  as  hard  as  stone  and  only 
to  be  ["('moved  from  the  root  of  the  tooth  by  the  dentist's  tool-.  Pres- 
sure upon  the  u'um  causes  ;l  drop  of  pus  in  exude  from  this  pocket  and 
the  suppuration  is  so  active  that  another  drop  can  be  expressed  five 


CtH)  MKD1CAI.    KLKCTKlriTY    AM)    K(  >NT(i  K.N     HAYS 

minutes  later.  The  aKeolus  or  bony  socket  in  which  the  tooth  sets  is 
partly  or  completely  absorbed.  The  affected  teeth  become  loosened 
and  eventually  drop  out  unless  the  process  is  arrested.  The  teeth 
themselves  are  more  apt  to  be  sound  than  to  be  decayed,  and  many 
of  them  are  of  ivory  hardiness.  So  much  has  been  written  about  the 
probable  causation  of  this  disease  that  its  determination  need  not  be 
attempted  here.  The  general  condition  which  may  be  termed  the 
uric-acid  diathesis  has  been  said  to  be  the  cause  of  the  trouble.  Hy 
other-  it  i-  attributed  to  a  local  infection,  most  probably  by  a  variety 
of  yeast  fungus.  The  present  author  has  treated  a  large  number  of 
these  cases  and  has  studied  the  reports  of  cases  treated  elsewhere,  and 
it  does  not  seem  probable  that  it  is  due  to  any  single  specified  cause. 
The  etiology  seems  to  present  more  or  less  analogy  to  that  of  chronic 
ulcers  of  the  legs.  (  lo  into  any  clinic  and  look  at  these  poor  leg  cases 
and  you  will  see  fat  and  thin,  anemic  and  plethoric,  people  with  varicose 
veins,  but  a  greater  number  without  them,  men  and  women.  There 
is  only  one  striking  fact  about  them,  and  that  is  that  the  percentage 
of  chronic  ulcers  of  the  leg  among  clinic  cases  is  many  times  greater 
than  in  private  practice.  Of  course1,  the  leg  is  exposed  to  injury  and 
its  circulation  is  peculiarly  liable  to  interference,  but  the  constitutional 
condition  which  causes  an  ulcer  to  develop  and  remain  open  for  half 
a  lifetime  must  be  brought  about  in  many  different  ways.  Similarly. 
in  a  case  of  Higgs'  disease,  there  may  be  found  some  definite  constitu- 
tional condition,  like  uric  acid,  diabetes,  or  anemia,  which  should  be 
remedied.  More  often,  however,  the  cause  is  indefinite  and  the  best 
that  can  be  done  constitutionally  is  to  recommend  fresh  air,  exercise, 
suitable  diet,  and  possibly  tonics.  Locally,  the  services  of  the  dentist 
.-hould  precede  those  of  the  elect  rot  herapeut  ist .  All  the  stony  deposits 
-hould  be  scraped  away  and  an  application  such  as  peroxid  of  hydrogen, 
glacial  acetic  acid  properly  diluted,  t irchloracet ic  acid  properly  diluted, 
nitrate  of  -ilver  of  the  proper  strength,  or  tincture  of  iodin. 

The  electric  application  which  the  author  has  found  successful  in 
cases  of  pyorrhea  alveolaris  is  a  combination  of  the  .r-ray  and  high- 
frequency  currents.  For  these  cases  an  ordinary  .T-ray  tube,  such  as  a 
")0-cin.  heavy  target  Miiller  tube,  is  encased  in  a  locali/ing  shield  having 
a  2',-inch  opening.  The  rays  should  be  about  No.  1  of  the  Walter  or 
of  the  |'etioi-t  -cale.  the  resistance  equal  to  a  parallel  spark  of  about 
2  inches,  the  primarv  current  about  '.'>  amperes,  with  a  12-inch  coil  and 
\\elinelt  interrupter  and  a  current  of  1  or  2  miHiamporos  passing  through 
the  .r-ray  tube.  The  anticathode  of  the  tube  is  about  10  inches  from 
the  face,  the  lip-  are  open,  exposing  the  teeth  and  gums,  and  the  time 
-ure  i-  fn.m  one  to  two  minute.-.  Treatments  are  given  twice 
and  are  -o  retaliated  as  to  produce  no  redness  ol  t  he  skin  and  no 
iiit  of  the  moustache.  A  special  .r-ray  tube  may  be  used  which 
entirely  of  lead  'j.la-.-  except  at  the  end  of  a  prolongation  to  be 
directly  to  the  u'lims.  The  tube  ha-  an  insulated  handle  and 
in  po-itioii  by  the  hand.  It  i-  necessary  to  have  conducting 
>  completely  in-ula  ted  as  not  to  give  a  spark  to  pat  i  cut  or  opera  - 
toi  il  accidentally  touched.  The-e  are  made  of  I'mlit  weight  and  are 
al  convenience  in  other  cases  be-ide-  thi<  particular  one.  The 
li'_:ht-  up  with  a  blue  radiance,  showing  the  u-ual  line  of  demarca- 
•  ii  between  tin  li'jiit  and  dark  hemi-phere-.  when  the  current  is  of 
the  niilit  polarity.  No  .r-rav  e-cape-  from  the  tube,  however,  except 


HIGH-FREQUENCY    CURRENTS 


017 


at  the  end  of  the  prolongation;  and  the  piece  of  ordinary  glass  present 
at  this  point  shows  the  ordinary  yellowish  radiance  of  an  x-ray  tube. 
The  time  of  exposure  is  about  the  same  with  this  tube  in  contact  with 
the  gums  as  with  t  he  regular  .r-ray  tube  at  the  usual  distance  because 
the  strength  of  application  is  about  one-eighth  as  great  as  with  an  ordi- 
nary .r-ray  tube.  In  use  this  tube  will  stand  only  a  very  moderate  current 
for  two  reasons:  first,  that  from  its  small  size  it  heats  up  readily,  and 
second,  that  its  resistance  is  much  less  t  han  t  hat  of  an  ordinary  x-ray  tube, 
and  with  the  same  adjustment  of  the  x-ray  coil  this  tube  will  transmit. 


Fiir.  3S4.—  El 


1  or  o  milliamperes  while  the  ordinary  tube  will  transmit  only  1  or  2  with 
1  he  same  degree  of  vacuum.  This  latter  Fact  contributes  very  largely 
to  t  he  rapid  overheating  of  the  tube.  The  t  ube  should  not  be  run  much 
more  than  half  a  minute  continuously,  and  then  should  be  allowed  to 
cool.  The  redness  of  the  anticathode  furnishes  the  guide  to  this. 

Immediately  after  the  .r-ray  treatment  the  high-frequency  currents 
are  applied  by  means  of  vacuum  electrodes  placed  in  direct  contact 
with  the  gums.  These  are  made  with  an  insulated  stem  with  double 
glass  walls,  so  that  the  lips  receive  none  of  the  current,  and  this  also 
enables  the  patient  to  hold  the  electrode.  For  this  purpose  a  very 
light  conducting  cord  is  attached  to  the  electrode  by  a  light  clamp. 
The  electrodes  are  made  in  different  shapes  for  application  to  lingual 
or  buccal  aspect  of  the  gums  (Fig.  oS-1).  The  proper  strength  of  cur- 
rent is  about  7")  milliamperes.  The  electrode  is  held  against  one 
part  of  the  gums  for  thirty  seconds  and  then  changed  to  some  other 
part.  It  is  not  kept  in  motion  as  is  necessary  with  the  stronger  appli- 


bib  MEDICAL    ELECTRICITY    AND    KoNTCiEN    KAYS 

cations  that  are  made  upon  the  surface  of  the  body.  The  application 
is  entirely  painless.  The  moment  the  current  is  turned  on  a  strong 
taste  of  o/.one  or  of  nitrogen  pentoxid  is  noticed. 

This  combined  method  of  treatment  is  given  three  times  a  week. 
The  results  are  very  prompt  relief  of  pain  and  improvement  in  the 
ulceration.  so  that  in  three  weeks  the  dentist  almost  always  reports 
that  the  teeth  are  better  than  for  six  months  previously.  The  teeth 
gradually  tighten  up  and  the  tenderness  disappears.  At  about  this 
time  the  trouble  -eeins  to  have  been  narrowed  down  to  one  or  two 
teeth  and  these  are  not  at  all  bad.  Just  at  this  stage  the  patient  is  only 
too  apt  to  consider  himself  practically  well  and  to  discontinue  treat- 
ment. This  i-  a  irrave  error  and  is  sometimes  followed  by  a  return 
of  the  trouble.  The  cases  in  which  the  results  are  most  brilliant  are 
those  with  ragged  looking  ulceration  of  the  gums.  Tho.-e  which  appear 
to  be  susceptible  of  only  a  moderate  amouet  of  benefit  are  those  with 
rather  a  clean  giimival  border,  but  with  a  pale  cartilaginous  appearance, 
looking  as  if  the  gums  would  not  bleed  if  cut  with  a  knife.  These  cases 
are  often  dependent  on  anemia  and  the  indicat  ion  is  for  fresh  air,  exercise, 
and  tonics  rather  than  for  local  applications.  It  appeal's  probable 
that  many  of  the  cases  of  this  disease  can  be  permanently  cured  and  the 
teeth  saved  by  this  treatment  combined  with  proper  care  by  the  dentist. 

Action  of  (In  :c-li<i>/  in  Pi/orr/na  Alrtoluri*. — The  author  has  many 
time-  >een  positive  results  in  the  cure  of  cases  which  had  resisted  the 
u-ual  treatment  by  the  dentist,  so  that  his  confidence  is  not  shaken  by 
the  theoretic  objections  which  he  has  heard  urged  against  it.  Thus,  it 
ha-  been  said  that  the  .r-ray  is  filtered,  and  so  altered  in  character  by 
pa--ing  through  the  soft  and  bony  tissue.-  as  no  longer  to  produce  the 
effect  which  it  might  if  the  lesion  were  in  the  superficial  tissues.  The 
answer  to  thi.-  argument  is  that  a  profound  effect  takes  place  in  the 
treatment  of  leukemia  by  .r-radiation  of  the  marrow  of  the  long  bones 
through  the  skin  and  flesh  and  bone.  If  the  blood-forming  cells  in  the 
bone-marrow  can  be  so  affected  as  to  produce  a  radical  change  in  the 
con-iit  ut  ion  of  t  he  en  t  ire  blood  in  The  body,  it  is  easy  to  comprehend  that 
nidi  a  radiation  can  produce  an  effect  niton  the  cells  lining  the  alveoli, 
and  experience  has  abundantly  j (roved  that  this  effect  is  a  beneficial  one. 

High-frequency  Currents  in  Diseases  of  the  Eye.-  Trm-hot/m. 
or  granular  lids,  has  been  treated  successfullv  bv  a  combination  of  the 
./•-ray  and  hiu'h-trequency  currents.1  A  vacuum  electrode  was  applied 
to  both  the  inner  and  outer  surfaces  of  the  lid.- 
three  times  a  week.  A  current  of  about  ~>() 
effi  ••  :  -mi  able.  A  cure  was  et'lect  ed  m 
b-'in-  from  three  weeks  to  three  months. 
met  hoi  L-  i  if  !  real  im-m  for  t  hi-  affect  ion. 

.  1  '•"••.          •  •    iifttic  in  rn    i-  a  disc 
'  :.•      ,  •    oi    hiLih -frequency   currents. 
d   to  the  temple  by   a 
1  ::  111:11  !<•  wit  h  t  he  skin 

The    elect  rode     W<  Mild     be    kept     m     mot  \( 

'  empie  a  milder  applicat  ion  of 
o'.  ei    tl  e  Hosed  eyelids. 

iii'n/1/.- 1 .-•  ni  tin    iH-nlnr  nnixc.h'*  ha-  been  considered  under  the 
I'  I  )i-e;i-<--  of  the  Nervous  System. 
'<;.'\    'T.  .I'.'innl  MI    \.lv;inri-il  Therapeutic-.  New    York.  May,  l'."H. 


HIGH-FKKQrKXC'Y    CURKKNTS  619 

High-frequency  Currents  in  Diseases  of  the  Nose.—  (Jzcna. — Suc- 
cessful cases  have  been  reported1  in  which  the  crusts  and  the  offen- 
sive odor  disappeared  and  the  mucous  membrane  assumed  a  healthier 
aspect.  In  about  an  equal  number  of  cases  (10)  treated  by  other 
observers-  the  results  have  been  less  promising.  Even  in  these  cases 
there  was  a  feeling  of  relief  for  twelve  or  twenty-four  hours  after  each 
treatment,  with  less  crusts,  greater  freedom  of  the  nostrils,  more  liquid 
discharge",  and  less  dryness  of  the  throat.  There  was  a  return  of  the 
symptoms,  but  in  the  long  run  there  was  decided  improvement.  This 
consisted  in  a  lessened  production  of  crusts,  the  nasal  mucus  became 
more  fluid,  there  was  less  offensive  odor.  Objectively,  the  mucous 
membrane  appeared  but  little  changed ;  the  atrophy  of  the  turbinates 
was  about  the  same.  The  treatment  is  not  unpleasant  and,  as  may 
be  seen  above,  even  the  less  favorable  results  show  appreciable  improve- 
ment. Returning,  however,  to  the  successful  cases,  a  complete  cure 
was  not  obtained,  but  such  great  improvement  as  to  get  rid  of  the  offen- 
sive symptoms. 

The  method  of  application  is  by  means  of  a  metal  rod  with  an  insu- 
lated handle.  The  part  which  .is  introduced  into  the  nose  is  covered 
with  sealing  wax  or  hard  rubber.  When  the  current  from  the  Oudin 
resonator  is  turned  on  an  effiuve  of  fine  sparks  escapes  from  the  rod 
through  the  hard  rubber.  These  fine  sparks  are  applied  to  ever}'  bit  of 
the  affected  mucous  membrane.  After  a  few  minutes'  application  the 
electrode  is  removed  and  if  the  patient  blows  his  nose  all  the  crusts  will 
usually  come  away.  The  application  lasts  about  fifteen  minutes  and 
should  be  made  every  other  day;  50  to  To  milliamperes  is  the  proper 
strength  of  current.  Xo  cocain  or  other  local  anesthetic  is  needed. 

Unij-fcrcr. — The  author  suggests  the  use  of  a  glass  vacuum  electrode, 
insulated  by  a  double  wall  except  at  its  extremity,  which  may  be 
applied  to  all  parts  of  the  nasal  mucosa,  but  especially  to  the  inferior 
and  middle  turbinated  bones.  It  is  very  easy  to  get  a  spark-effect 
from  an  electrode  of  this  size  even  if  the  contact  is  pretty  good:  and 
this  seems  to  be  the  indication  in  these  cases.  This  vacuum  electrode 
will  give  one  all  the  benefit  of  the  high-frequency  currents  combined 
with  the  influence  of  the  ultraviolet  radiation  from  the  tube.  A 
similar  application  mav  be  made  to  the  outer  surface  of  the  nose,  at 
the  sides  halfway  from  the  root  to  the  tip.  The  strength  of  current 
fin1  the  interior  of  the  nose  is  from  oO  to  7")  milliamperes.  And  for  the 
outside  a  current  of  75  to  12o  milliamperes,  applied  by  a  somewhat 
larger  electrode  with  an  uninsulated  stem  and  terminating  in  a  ball. 
This  shape  gives  the  spark-effect  desired  in  these  cases. 

Sinn*ifin.-  Chronic  inflammation  in  the  frontal  sinus,  the  ethmoid 
cells,  and  the  antrum  has  yielded  to  high-frequency  applications  at  the 
author's  hands.  A  small  glass  vacuum  electrode  has  been  connected 
with  the  Oudin  resonator  and  is  passed  over  the  surface  of  the  affected 
parts  of  the  face  by  the  patient  herself  (Fig.  oS-">\  The  strength  of  cur- 
rent i-  -uflicient  to  redden  the  skin,  but  not  to  cause  pain. 

High-frequency     Currents    in    Diseases    of    the     Ear. —  Tinnitus 


MEDICAL    KI.KCTRien  Y    AND    KONTCKN     KAYS 


Aitrinin. — The  etfluve  from  an  <  hulin  resonator  is  applied  by  means  of 
an  elect  rode  consisting  oi'  a  bundle  of  fine  wires  surrounded  by  a  "'lass 
cylinder.  The  ulass  can  be  made  to  project  anv  required  distance 
beyond  the  wires;  the  object  lieinu'  to  secure  ail  effllive  of  fine  violet 
-parklets.  This  is  applied  to  the  skin  behind  the  affected  ear  for  three  to 
six  minutes;  it  is  practically  painless  and  is  alwavs  easily  borne.  There 
is  some  redness  of  the  .-kin  and  even  a  slight  burn  if  the  application  has 
been  too  vigorous.  The  patient's  sensations  are  not  a  reliable  guide, 


a-  even   entirely  too  -Iron^r  an  applicat  ion   would  not   be  really  painful. 

\   currenl    oi    ;iboul     KM)    rnilliamperes    with    the   end-  of  the  wires  well 

led    \vithin    the   "la.--  cuff  would   be  proper  for  a   starting-point. 

!     ..  •!<•").   p.  .")M».   -how-   the  proper  elect  rode. 

I  he    application    -hould    be   made  three    time-  a    week  and    mav  be  to 

ears  according    to    the   case.      Iinbert1   ha-  treated  a  larti'e 

•  r   'it    ea-e-    lit    tinnitus   aiirium    due    to    a    \'ariet\p   <i|    eaii,-es,   and 

found  tho-e  \\ithout    antecedent   ,-uppurat  ion  were  alwavs  readilv 

Jo  it  M.il  i|c.-   I'l'.-ict  icieiis,    I  )'•('.    17,    I'.tn.",. 


Hi(;i[-Fiu-:QrK\rY  (.TKKKNTS  021 

and  permanently  cured,  \\hcthcr  the  lack  of  success  in  cases  flue 
to  suppurative  middle-oar  disease  indicates  absolute  failure  of  this 
method  in  those  cases  or  simply  that  they  respond  much  more  slowly 
is  a  question  which  has  not  yet  been  decided. 

When  the  noises  in  the  head  are  not  of  too  long  standing  or  too 
intense,  improvement  is  usually  not  iced  by  the  fifth  or  sixth  treatment. 
In  one  severe  case  (Dr.  Maquez)  there  was  no  improvement  for  a  whole 
month,  and  then  it  was  only  slight  and  temporary,  nevertheless  a  cure 
was  ultimately  obtained.  Then1  is  then  no  definite  time  during  which 
the  treatment,  should  be  tried.  The  improvement  which  takes  place  is 
not  uniformly  progressive.  During  the  course  of  the  treatment  there 
may  be  many  relapses,  but  the  noises  are  not  so  loud  and  they  soon 
e-ease  again.  It  is  very  necessary  to  continue  the  treatment  for  a  month 
after  the  patient  seems  entirely  cured.  According  to  Imbert 's  ob.-er- 
vations,  this  treatment  does  not  result  in  any  improvement  of  hearing 
if  that  has  been  impaired.  He  considers  the  beneficial  effect  to  be  due  in 
some  cases  to  a  revulsive1  action  and  to  the  reduction  in  arterial  tension, 
which  is  one  of  the  constitutional  effects  of  high-frequency  current-. 

High-frequency  currents,  according  to  Imbert.  Denoyes,  and  other-. 
constitute1  the  best  treatment  for  vascular  tinnitus  aurium.  The  treat- 
ment is  directed  to  the  general  vascular  condition  and  not  devoted 
alone  to  local  applications. 

Marage  reports  good  results  from  the  autoconduction  cage  about 
the  head  and  shoulders,  and  vibration  applied  to  the  temporoparietal 
region. 

Skin  Diseases. — A  method  which  is  very  generally  useful  is  by  t  he- 
application  of  an  cffluve  from  the  Oudin  resonator,  or  similar  high-ten- 
sion high-frequency  apparatus  for  ten  or  fifteen  minutes,  followed  by  the 
application  of  a  few  sparks  from  a  lower  tension  apparatus.  The  latter 
effect  may  be  obtained  by  having  the  patient  hold  a  metallic  electrode 
connected  with  the  lower  terminal  of  the  Oudin  resonator,  and  drawing  a 
few  sparks  from  the  affected  part  of  the  body  by  means  of  the  operator'- 
hand  or  a  damp  sponge1.  A  metal  key  or  coin  will  do  this  effectively, 
but  less  agreeably  to  the  patient.  All  the  different  skin  lesions  referred 
to  as  amenable  to  static  electricity  yield  still  more  readily  to  high-fre- 
quency currents. 

Sonii'  special  applications  >/iai/  be  mentioned:  Tclangiectatic  rcrlm**  oj 
llt<  nos<  may  be  treated  by  the  effluve  or  spark-  from  the  Oudin  reso- 
nator, or  by  the  application  of  a  condenser  electrode  and  d'Arsonva! 
currents.  The  same  applications  are  useful  for  liipitx  I'lilt/arix  and  ery- 
ihi  t/Kifni/i  N.  The  effluve  is  valuable  in  acne,  itn/x-tit/o,  Inrpc*  zoxter, 
furunciiloxis,  and  xi/coxi*.  Alopecia  sometimes  yields  to  the  effluve.  but 
more  often  requires  sparks. 

The  application  of  high-frequency  spark-  of  different  strength-  i-  a 
wonderful  resource  in  epithelioma  and  in  carcinoma  and  lupus. 

Freund  and  Fabroz/i1  find  that  high-frequency  sparks  applied  to  the 
normal  skin  produce1  inflammation  of  the  mo-t  -uperficial  laye-rs,  givat 
dilatation  of  the  veins,  extravasations  of  Mood,  and  vacuolization  of  tin.1 
walls  of  the1  arteries.  There'  may  be1  destruction  of  the  entire  epithelial 
layer.  Oudin  regards  these  results  as  partly  due  to  the  ultraviolet 
radiations  which  accompany  the  product  ion  of  the-e  spark-. 

U'a/'/.v,  xninll  epithcliomata,  and  molt*  may  be  destroyed  bv  the  u-e 
1  Annali  di  cllctricitii  mnlira,  1 '.«):>.  No.  11. 


(>22 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


of  high-frequency  currents  as  a  cauterizing  agent.  For  this  purpose  a 
metal  electrode  or  small  glass  vacuum  electrode  is  held  upon  the  spot 
to  he  treated  and  a  current  of  !;">()  milliamperes  is  sent  through  it  by  the 
(  Hulin  resonator  or  the  d'Arsonval  transformer  for  ten  or  twenty  seconds. 
Histologic  investigations  hy  Arienzo  and  Fahrozzi1  show  that  tlie  epithe- 


lial elements  of  the  skin  are  most  powerfully  influenced,  active  hyper- 
emic  changes  taking  place  in  the  .surrounding  area,  with  exfoliating 
scabs  as  an  end-product.  The  repair  of  the  lesions  produced  by  the 
treatment  lakes  place  by  a  process  of  leukocytosis  and  phagocytosis  in 


'!:'  -ubfutam-iiu-  ti.--.ucs.  rc.-ulting  in  the  complete  regeneration  of  the 
'•pit  he!i;d  -trata  of  the  -kin.  The  resulting  ciratrix  i-  preferable  to  that 
produced  l.y  the  operation  of  chemic  can-tic.-  or  exci-ion  and  the  appli- 
••at  ion  i-  ctinipa  ra  '  ivl  v  |  >ainle-s. 

I-  in  i  n  i  •-  os'  i   ;;vs  -how  an  ex  t  feme  case  t  real  ed  1  >v  t  he  a  ut  hot'.      Tin 're 
1  .I'-ur.  A.iv;inri><l  Thcrnp.,  April.   !'.«)-}. 


HKiH-FKKQrK.NCY    <  TKKKNTS 


was  a  flat   warty  surface  almost   surrounding  the  h^  near  the  man's 
ankle.      It   had  existed  for  about  two  years  in  spite  of  medicinal  appli- 


Fip.  3SS.1 — Another  view  of  the  same  rase  as  Fig.  3XG. 


cations.     A  shower  of  lonji  white  spai'ks  wa>  applied  at  different  point? 
over  the  entire  surface,  not  lonu;  enouirli  at  one  place  to  produce  necrosis 


(124 


MKIHCAI,     KLK(TKl<ITY     AM)    KoNTOKN     KAYS 


Karh  treatment  was  followed  by  visible  improvement  and  in  a  few 
week-  the  surface  had  become  normal. 

Figure  :>S',t  shows  a  cavernous  epit  helioma  or  endot  helioma  of  t lie  face 
which  re-i-ted  .r-ray  treatment  and  which  was  completely  destroyed  by 
a  -iniile  ap])lication  of  -park<  from  a  metallic  electrode  connected  with 
one  pole  ( it  t  he  refloat  or. 

Figure  :•!'.»( i  i-  of  a  case  of  flat,  scaly,  pigmonted  keratosis,  apparently 
threatening  to  liecome  epithelioma,  which  made  such  slow  progress  under 


.'  tieiitment   that   a  sinu'le  application  of  hifi'h-frequency  sparks  wa- 
•  with  complete  removal  of  the  lesion. 

fie  author's  hijih-frequency  -park  elect  i-od<-  and  ,-pecial  technic  are 
iftalit   unle--  the  patient   i<  under  a  general  ane-t  het  ic. 
'hey  render  the  application  painless  fsee  p.  ."*().'>  J. 

':. '•-'•   are   practicallv    th'1  onK"   case.-;   \\\    \\hlch    ;m    irnlatr/e  ('ffect    i.- 

••  <\.      (".-ually  the  application  of  hiirh-fi'equency  currents  i-  so 

ev<  n    witli    verv  sti'on^  current-   no   irritation   of  the  skin   is 

i'-i-d.       I  hi-   i-  !_;cnerallv  afcompli.-hed  b\'  maintaining  a   uood  con- 

-l.in    ,-ind    b\"   keepini;'  the   \'aciium    I'lcct  rode   iii   constant 

in.      I   mpolar    applications    of    L'.~»0    milliamperes    may    be    ^i\'en 

ithoin    irritation.      If.   for  any   reason,   it    is   necessary  or 

':>.'    to  •         •    '};<•  application  through  \}\<-  clothes  or  bandage.-,  the 

:    be   pressed  quite  firmlv,    it    should   be   kept    in   motion, 

;    be   moderate,    not    over    1  ">0   milliamperes,   and    the 

\vhole  hii£li-fre()uency  a])jKtratus  ,-hould  be  such  as  to 

ni   rather  than    ten-ion.     Tin.-  difference  manifests 

une  r-a.-e  b\-  -iMi|ilc  warmth  \\hen  the  electrode  is  in  contact 

hen    the    appal'alu-    I-    adju.-ted    lor   tension    there 


N'CY    CUllUKNTri  025 

are  disagreeable  sparks  passing  down  from  the  outer  surface  of  the 
vacuum  tube  even  when  the  latter  is  in  good  contact  with  the  skin. 
Increase  in  tension  is  produced  principally  by  lengthening  the  spark-gap 
between  the  Leyden  jars.  The  volume  of  current  is  increased  by  using 
greater  self-induction  in  the  primary  coil,  arranging  the  interrupter 
so  as  to  give  rapid  interruptions  and  a  strong  current,  and  using  a  large 
number  of  turns  in  what  may  be  termed  the  primary  part  of  the  Oudin 
resonator  or  the  d'Arsonval  transformer.  It  is  also  increased  by  the 
use  of  vacuum  electrodes  having  leading-in  wires;  and  especially  by  the 
use  of  metallic  electrodes.  The  eifluve  is  increased  by  a  combination 
of  the  elements  which  increase  both  tension  and  volume. 

Acne  is  benefited  by  the  local  application  of  high-frequency  cur- 
rents, either  theeffluve  or  by  a  vacuum  electrode.  The  latter  is  more 
useful.  The  electrode  should  be  dome  shaped  and  at  least  1  inch  in 
diameter,  the  flat  surface  being  applied  to  the  skin.  The  use  of  talcum 
powder  is  desirable  to  secure  a  good  contact  while  the  electrode  is  kepi 
in  rapid  motion.  A  current  of  about.  100  milliamperes  should  pass 
through  the  glass  electrode  for  about  ten  minutes  and  sparking  should 
be  avoided.  The  applications  should  be  made  three  times  a  week. 
The  beneficial  effect  is  largely  due  to  simple  stimulation,  but  there  is 
also  a  germicidal  effect  from  the  ozone  generated  in  the  tissues  by  elec- 
trolysis and  from  the  ultraviolet  ray  produced  around  the  vacuum  tube. 
The  electrodes  best  adapted  to  almost  all  high-frequency  applications 
are  those  which  produce  the  greatest  amount  of  ultraviolet  light.  Its 
presence  is  demonstrated  by  \Villemite,  the4  same  mineral  that  is  used 
as  a  test  for  radium  rays.  The  x-ray  and  high-frequency  currents  may 
be  combined  in  the  treatment  of  these  cases.  It  is  easier  to  get  a  per- 
manent cure  in  these  cases  by  using  in  addition  to  the  electrotherapy 
the  author's  treatment  by  tar-soap  friction,  xinc  and  salicylic  ointment, 
and  rhubarb  and  soda  internally.  This  is  given  in  detail  on  p.  1172. 
Treatment  by  incision  and  curetting  is  to  be  avoided.  It  often  results 
in  the  most  frightful  scarring.  Success  ma}' be  confidently  expected  in 
these  cases,  but  it  requires  months  of  treatment.  Special  sources  of 
reilex  irritation  like  phimosis  should  be  remedied. 

Alopecia.  -The  application  of  a  vacuum  electrode  carrying  a  cur- 
rent of  100  to  150  milliamperes  is  an  excellent  stimulant  to  the  hair- 
follicles  and  is  a  very  convenient  form  of  treatment.  The  prognosis 
varies  in  different  cases.  In  ordinary  cases  of  a  tendency  to  baldness 
high-frequency  currents  are  used  alone,  but  in  alopecia  areata  the.r-ray 
is  required  as  an  adjuvant . 

Treatment  of  Alopecia  Are«ta  hi/  Hii/h-frcqucnry  Sparks. — Bordier, 
Bordet.  and  others  have  reported  successful  cases.  Bordier 's  technic 
employs  for  recent  mild  cases  an  Oudin  spark  electrode  with  a  glass 
sleeve1.  This  is  connected  with  one  pole  of  a  large  d'Arsonval  trans- 
former, the  other  pole  of  which  is  grounded.  A  shower  of  tiny  painless 
sparks  are  applied  in  this  way  over  one  p;irt  after  another,  long  enough 
in  each  place  to  produce  intense  redness,  but  not  vesication.  It  requires 
only  a  few  seconds  in  each  place.  Bordet'  cured  a  case  which  had 
resisted  all  sorts  of  treatment,  including  the  above  technic.  He  applied 
the  same  fine  sparks  for  twenty  or  thirty  seconds  at  a  time  in  each 
place.  The  entire  seal])  became  very  red  and  the  fifteen  or  twenty 
separate  places  to  which  the  sparks  had  been  applied  until  the  skin 

1  Arch,  d'clcotricitc  innlicalc,  Sept.  2.1.  1907. 
in 


b'2()  MEDICAL    ELEC'THK'ITY    AND    KONTGEN    KAYS 

turned  white  each  time  became  blistered.  This  latter  condition  was 
succeeded  in  a  day  or  two  by  thick  crusts,  sometimes  moist,  resting  on 
an  indurated  and  very  congested  base.  It  took  fifteen  days  for  a  very 
superficial  slough  to  separate,  leaving  a  superficial,  flexible,  pink  cicatrix 
which  became  brownish  about  the  thirtieth  day.  This  was  followed  by 
the  appearance  of  fine  hairs.  The  treatment,  which  was  a  painful  one, 
was  repeated  every  eight  days  until  two-thirds  of  the  hairy  scalp  had 
been  vesicated  in  this  way.  The  hair  was  completely  restored  in  about 
nine  month-. 

A  case  now  under  treatment  by  the  author  is  shown  in  Fig.  391.  A 
glass  vacuum  electrode  connected  with  the  Oudin  resonator  is  lightly 
rubbed  over  the  bald  areas  with  as  considerable  spark  effect  as  can  be 
borne  without  much  discomfort.  This  treatment  causes  redness,  of  the 


scalp,  but  no  blisters  or  scabs.  The  same  t  reat  merit  may  be  applied  so  as 
to  produce  the  more  severe  ef'iecl  above  described  if  the  vacuum  elec- 
trode i-  held  ;tt  a  little  distance  from  the  surface  and  a  shower  of  tiny 
-pa  rk-  i-  a  Mowed  to  f;i II  upon  1  he  same  -pot  for  t  went y  or  1  hirt  v  seconds. 

('hilhluitix  are  benefited  by  the  analgesic  and  vasomolor  tonic  effect 
of  the  hiidi-freqiiency  current  -.  A  vacuum  electrode  is  used  with  a 
current  of  about  1  (K)  milliampcres.' 

l:<'-.i  inn  in  practically  everv  form  i-  benefited  by  the  application 
of  hi(_rh-t  requencv  current-.  A  local  application  of  the  effluve  or  by 
vacuum  elect  null  -  i-  u-uallv  be-t .  This  should  not  be  confined  to  the 
region  of  the  le-ion,  but  should  extend  to  a  third  of  the  surface  of  the 


HIGH-FREQUENCY    CURRENTS  027 

body.  For  instance,  for  eczema  of  the  legs  the  application  should  be 
made  to  the  whole  of  both  lower  extremities.  The  vacuum  electrodes 
should  be  applied  over  smooth  dry  bandages  or  underclothes.  A  current 
of  50  to  7")  milliarnperes  with  scarcely  any  sparking  effect  even  through 
the1  clothes  is  applied  directly  over  an  acute  eczema,  while  about  150 
milliamperes  with  as  little  .sparking  as  possible  is  applied  over  the  un- 
affected skin.  The  applications  should  last  about  fifteen  minutes, 
during  which  the  electrode  is  kept  in  constant  motion;  and  should  be 
made  three  times  a  week.  As  the  case  improves,  stronger  applications 
are  made  over  the  lesion.  The  benefit  is  due  partly  to  the  local  effect, 
but  very  largely  also  to  a  systemic  effect,  by  which  all  the  processes  of 
metabolism  are  stimulated  and  the  condition  of  suboxidation  which 
causes  so  many  of  these  cases  is  remedied.  There  are  certain  cases  in 
which  the  skin  of  the  whole  of  both  lower  extremities  is  thickened, 
indurated,  and  brownish  red.  This  is  accompanied  by  annoying  pruri- 
tus and  seems  to  be  caused  by  the  uric-acid  diathesis.  High-frequency 
currents  produce  a  favorable  effect  applied  locally  or  generally.1 

Furuncle*  are  favorably  influenced  by  the  local  application  of  high- 
frequency  currents;  vacuum  electrode,  100  milliamperes  for  ten  minutes, 
with  the  electrode  moving  over  the  entire  region.  Sometimes  they 
are  aborted;  sometimes  made  to  heal  more  rapidly  after  incision.  This 
is  the  case  also  with  felons  and  cellulitis;  the  current  having  an  indirect 
bactericidal  effect.  A  local  application  of  high-frequency  currents 
immediately  before  an  operation  for  cellulitis  or  abscess  acts  as  a  local 
anesthetic. 

Herpes  zoxtcr,  with  its  half-girdle  of  eruption  and  severe  pain  and 
its  subsequent  depression  of  all  the  vital  forces,  is  successfully  treated 
in  this  way.  There  is  perhaps  no  better  analgesic  in  zoster  and  inter- 
costal neuralgia  than  the  application  of  high-frequency  currents  of  100 
milliamperes  by  vacuum  electrodes.  And  if  the  application  is  made 
not  only  along  the  course  of  the  nerve  but  also  along  the  spine  and  over 
the  abdomen,  the  disappearance  of  the  eruption  and  the  improvement 
in  the  general  condition  are  very  prompt.  Herpes  in  other  regions 
and  of  other  types  rarely  requires  this  treatment  and  generally  there 
is  some  underlying  cause  whose  treatment  is  more  important  than 
that  of  the  cutaneous  lesion. 

Impetigo,  again,  is  a,  disease  favorably  influenced  by  the  local  appli- 
cation of  high-frequency  currents  freely  over  all  the  affected  regions; 
100  milliamperes  is  the  proper  strength  of  current  with  the  Oudin 
resonator  and  glass  vacuum  electrodes  with  leading-in  wires. 

Indurated  cicatrices  yield  to  treatment  by  high-frequency  currents; 
vacuum  electrode  100  milliamperes  for  about  five  minutes  three  times 
a  week,  keeping  the  electrode  in  motion.  The  .r-ray  has  the  same  effect 
of  causing  the  disappearance  of  the  induration  by  a  process  of  absorp- 
tion and  the  two  methods  of  treatment  may  be  combined.  Kach  ses- 
sion would  consi>t  of  a  mild  application  of  the  .r-ray  followed  by  the 
use  of  t  he  vacuum  elect  rode. 

Kcloul  has  been  treated  by  the  .r-ray  and  high-frequency  currents 
and  often  successfully. 

1  A-  medicinal  agents  in  these  rases  the  best  effects  are  obtained  from  boric  arid 
ointment  externally  and  two  .">-<;rain  tablets  of  salophen  three  or  four  times  a  <lav 
internally.  The  latter  is  entirely  innocuous  and  may  be  taken  for  a  number  of 
months  even  by  the  most  delicate  old  lady. 


MEDICAL    ELECTRICITY    AND    KONTGEN    HAYS 

Keloids  may  sometimes  be  made  to  disappear  and  remain  away  by 
applications  of  a  high-frequency  high-tension  electrode,  at  first  directly 
in  contact  and  then  slight  ly  separated,  so  as  to  produce  a  shower  of  short 
sparks  distributed  over  the  surface.  A  sort  of  crust  is  produced  which 
falls  off  in  a  week  or  so.  Thirty  or  forty  treatment-  are  required  to 
effect  a  cure.  A  case  of  wide-spreading  keloid  of  t  he  interscapular  region 
was  treated  in  thi-  way  at  St.  Bartholomew's  ( 'linic  and  returned  a  year 
later  completely  cured. 

Keloid  appears  to  the  author  to  be  so  distinctly  due  to  a  constitu- 
tional tendency  that  local  applications  are  as  likely  to  result  in  disap- 
pointment as  are  surgical  operations  unless  accompanied  by  systemic 
treatment.  Thiosinamin,1  a  drug  introduced  by  the  author  in  ls!)l 
for  the  treatment  of  this  diathesis,  has  given  good  results  when  com- 
bined with  these  or  other  local  applications.  It  may  be  given  inter- 
nallv  in  a  o-uTain  capsule  every  night  ju.-t  before  getting  into  bed.  and 
should  be  taken  more  or  less  continuously  for  six  months  or  so. 

I. n/ui*  Ki'iitln  n/ntoxHx. — A  large  number  of  cases  have  been  treated 
by  Bisserie.  Jacot.  and  others,  with  a  complete  cure  in  over  ">()  per  cent. 
The  application  is  a  local  one.  either  by  the  effluve  or  by  means  of  vacuum 
electrodes.  Iii  the  latter  case  a  current  of  about  100  milliamperes 
should  pass  through  the  electrode  for  about  ten  minutes,  the  electrode 
being  kept  in  motion.  There  are  cases  which  sometimes  do  not  yield 
to  r-ray  or  ultraviolet  ray  treatment,  but  in  lupus  vulgaris  either  of 
these  methods  seems  preferable  to  the  treatment  by  high-frequency 
current  -. 

M  nil  usi'ii  1,1  rontri(jiosnni  is  one  of  the  disease-  in  which  a  cure  has 
been  reported  from  the  local  application  of  high-frequency  currents 
'irlass  vacuum  electrodes  with  a  current  of  100  milliamperes). 

I'rnrit us.  —  -For  this  symptom  in  almost  any  locality  high-frequency 
currents  are  almost  a  specific.  Pruritus  ani  is  considered  under 
the  head  of  Rectal  Diseases.  p'J.-ewhere  the  application  should  be  by 
the  effluve.  taking  care  not  to  give  many  act  ual  sparks,  or  by  the  vacuum 
electrode.  In  the  latter  case  there  should  be  a  good  contact  with  the 
skin,  facilitated  by  the  use  of  powder,  the  current  should  produce  very 
decided  warmth  with  hardly  any  sparking,  about  b">0  milliamperes 
Relief  i.-  usually  apparent  at  once.  The  production  of  a  slight  rash 
like  "  pnckl  v  heat  "  bv  high-frequency  i  real  men  t  is  usually  unnecessary 
and  in  thi-  case  would  be  <|uite  undesirable. 

/'."W/'/N/x   yield-   to   high-frequency    treatment    just    as    it    does   to   so 

other   stimulating   local    application-,   and   some   cases   have   been 

reported    where    the    re.-iills    appeared    to    be    permanent.      The   effluve 

or  t  he  Lrlas.-  vacuum  elect  rode  is  applied  over  the  <  ht't'erent   lesions  wit  h  a 

:|i    o|     7")    to    1 1  H  i    milliamperes   and    -ome   slight    .-park-effect    cau- 

pli<  d.      The  latter  had  better  be  more  of  the  nature  of  a  loose 

con'act    with    the    skin    than  ot    .-park-   trom    an   electrode  held    at    any 

•  ce   from    the  surtace.      I  In-   treatment    certainly  has 

i  he   general    system    and    so  will    probablv    vield    a 

:•  ,,:'.•.'  ,  rcentage  oi  cures  than  the  ordinary  medicinal  local 


ivc   in  simple   in- 


HHlH-FKKQrFAVY    CUKKKXTS  ()29 

selves.  The  preferable  method  is  to  have  some  thin  dry  covering  over 
the  surface  and  then  to  apply  the  vacuum  electrodes  with  a  current  of 
not  more  than  100  milliamperes.  Have  very  little  spark-effect  and 
keep  the  electrode  in  motion. 

Here,  as  in  psoriasis  and  ec/ema,  the  application  is  much  more 
cleanly,  agreeable,  and  convenient  than  any  local  medicinal  application. 
And  to  the  local  effect  is  added  the  beneficial  influence  upon  the  sys- 
tem at  large. 

Skin-grafting. —Dr.  -I.  Sherman  \Yight  of  Brooklyn  has  used  the 
high-frequency  currents  in  the  surgical  operation  of  Thiersch's  skin- 
graft in»;.  The  surface  of  the  ulcer  is  freshened  by  cutting  away  a  very 
thin  layer.  The  usual  slow  process  of  checking  hemorrhage  by  pres- 
sure is  dispensed  with,  the  large  skin-grafts  being  at  once  applied. 
Sparks  from  a  high-frequency  apparatus  are  then  applied  To  arrest 
hemorrhage  by  causing  coagulation.  The  pointed  metallic  electrode 
is  held  about  I  cm.  above  the  surface  of  the  graft.  The  grafts  are  said 
by  Dr.  Rushmore.  another  surgeon  who  has  used  the  method,  to  adhere 
better  and  be  more  successful  than  if  the  electric  application  had  not 
been  made. 

Ulcers. — Chronic  ulcers  anywhere  and  of  any  nature  are  quickly 
and  favorably  influenced  by  high-frequency  currents.  Many  recom- 
mend the  efHuve,  but  as  may  have  been  noted  alreadv  the  author's 
favorite  method  is  by  rubbing  a  vacuum  electrode  over  a  light,  dry 
covering.  Tsing  this  method,  the  current  should  at  first  be  less  than 
100  milliamperes  with  as  little  spark-effect  as  possible.  After  the  ulcers 
are  practically  healed,  a  stronger  current  may  be  applied,  and  when 
there  is  no  raw  surface  at  all,  loO  milliamperes  will  be  found  to  have  a 
good  effect  upon  the  swelling  and  induration  so  often  present,  but 
even  then  care  should  be  taken  not  to  have  any  appreciable  sparking, 
and  at  the  appearance  of  a  little  red  punctate  eruption  the  strength  of 
the  application  should  be  materially  reduced. 

1'crforatinij  L'lcer  of  the  Foot. —  Oudin1  treated  such  a  case  successfully 
with  the  resonator  current  applied  through  a  metal  probe  covered  with 
:-otton  wet  with  a  solution  of  cocain. 

Xanthoma  Multiplex. — Cases  of  this  disease  have  been  treated 
successfully  with  the  .r-ray  alone'-'  and  by  a  combination  of  the  .r-ray 
and  high-frequency  currents. s  The  patches  treated  by  high-frequency 
currents  disappeared  if  the  application  was  severe  enough  to  blister 
the  skin,  otherwise  they  were  not  affected. 

In  all  these  cases  where  a  local  action  upon  the  skin  is  desired  tin- 
glass  vacuum  electrodes  seem  to  be  the  most  effective.  This  is  attrib- 
utable in  part  to  the  ultraviolet  ray  generated  by  the  tube.  The 
presence  of  this  invisible  light  can  be 
fluorescence  excited  in  a  piece  of  Wil 
elect  rodes. 

High-frequency  Currents  in  Periostitis,  Cellulitis,  Phlebitis, 
and  Varicose  Veins,  etc.—  \\  rioxtitix.—  Bilinkin*  gives  a  description 
of  1  1  cast's  treated  by  high-frequency  currents;  s  of  them  were  tuber- 
iti  (  Mlicid  ilc  la  Snrirtr  francaiso.  il'i-lcctrothcnipie.  .Ian.,  I'.'H.  vol.  \i\. 


Kvan- 


1  Hullo 
I'.HU.  abstract cil  in  Arc! 


()30  MEDICAL    ELECTRICITY    AND    HOXTGEK    HAYS 

cular,  and  all  were  cither  cured  or  very  much  improved.  Tho  appli- 
cations were  by  condensing  electrodes,  a  type  in  which  a  metal  rod 
passes  down  almost  the  full  length  of  the  hollow  glass  electrode,  being 
separated  from  the  glass  wall  cither  by  a  partial  vacuum  or  by  oil.  The 
discharge  from  such  an  electrode  is  unusually  rich  in  the  spark  element. 
The  applications  were  of  five  minutes'  duration  three  times  a  week. 
A  case  of  extensive  tubercular  periostitis  of  the  tibia  was  apparently 
entirely  cured  by  twenty  applications.  A  tubercular  affection  of  the 
metacarpophalangeal  joint  of  the  thumb  with  entire  loss  of  motion  and 
atrophy  of  the  thenar  eminence  and  involvement  of  the  skin,  with  the 
formation  of  five  sinuses,  was  likewise  treated.  Twenty  seances  resulted 
in  diminution  in  the  size  of  the  swollen  osseous  extremity  and  the  motion 
in  all  directions  had  begun  to  improve.  Dr.  Bilinkin  observes  that 


1  IL'.  •'•>'.!'_'. — Condensing  eU'rtrodi-  lor  surface  application. 

"in  rases  where  the  process  had  advanced  to  suppuration  and  sinus 
formation  the  response  to  treatment  was  quicker  than  when1  the  skin 
was  intact."  This  agrees  with  the  author's  view  that  the  beneficial 
effect  of  high-frequency  currents  in  suppurative  diseases  is  due  to  their 
fa  von  MIT  the  process  of  elimination.  An  (  hi  din  resonator  or  a  d  'Arsonval 
transformer  should  be  used  with  either  vacuum  electrodes  or  condensing 
electrodes,  applving  a  cm-rent  of  lo()  to  !?()()  milliamperes  for  five  or 
Ten  minutes  three  times  a  week.  If  the  skin  is  broken  the  author  pre- 
fer- 10  make  the  application  over  dry  dressings.  The  .r-ray  is  often 
of  service  in  combination  with  high-frequency  currents  in  these  cases. 

(',!',  ul it!.<  and  abscess  may  be  very  quickly  disinfected  after  incision 
and  caused  to  heal  promptly.  The  best  method  of  application  is  over 
a  moi.-t  dressing,  using  a  vacuum  electrode  from  the  <  hidin  or  the 
d  'Arsonval,  and  applving  a  current  of  1  .">(")  milliamperes  for  five  minutes. 
\Yhere  there  are  sloughing  tendons  or  ot  her  tissues  which  have  to  come 
away  bv  .-low  process,  healing  cannot  take  place  at  once,  but  even  here 
the  application  is  distinctly  worth  while  because  of  its  analgesic  and 

ant  isepl  ic  effect  S. 

I'lili  liifift  inn!  VnrirnKc  Veins.—  This  treatment  is  effective  in  reducing 
the  swelling  and  induration  remaining  after  an  attack  of  phlebitis  or 
periphlebit is.  Thi-  is  accomplished  by  its  eliminative  effect;  and  then 
if  the  treatment  is  continued  the  circulation  becomes  normal  and  the 
patient  is  -uved  from  the  consequences  oi  such  t  roubl<  —  ulcer  and 
vein.-.  In  a  case  referred  to  the  author  by  l)r.  Charles  McHur- 
circuniference  of  the  affected  leg  was  1  ,;  inches  greater  than 
he  sound  I'-tr.  There  were  characteristic  brownish-red  spots 
f  a  silver  dnllar  or  twice  that  -i/.e.  Over  i  he.-e  the  epidermis 
thin  ;ind  at  times  there  was  a  serous  discharge.  There  was 
sitv  as  vet.  The  treatment  by  high-frequency  currents  (ultra- 
vi  ilet  li-ht  the  patient  called  it  at  fi 
the  :.:•-!  aear;mcr  nf  the  trouble. 


HIGH-FREQUENCY    CURRENTS  631 

the  present  writing  the  case  has  remained  cured  for  two  years  after 
cessation  of  treatment.  The  swelling  disappeared  and  the  spots  on 
the  skin  are  normal.  The  treatment  consisted  in  the  application  of  a 
glass  vacuum  electrode,  connected  with  the  Oudin  resonator,  to  the 
whole  surface  of  the  limb.  Powder  was  used  upon  the  skin  and  the 
electrode  was  kept  in  motion.  The  current  was  at  first  1  oO  milliamperes, 
and  even  less  over  the  chronic  inflammatory  spots.  Later  it  was  grad- 
ually increased  until  200  milliamperes  were1  applied  to  all  parts  of  the 
limb.  While  under  the  author's  care  the  patient  was  taking  10  grains 
of  salophen  three  times  a  day  and  applying  an  ointment  of  salicylic  acid 
and  C'heeseborough  zinc-oxid  ointment  to  the  chronic  patches,  and  an 
elastic  stocking  was  worn.  The  treatment  was  given  three  times  a  week 
for  two  whole  winters. 

Cases  with  varicose  veins  require  a  very  much  longer  time  to  cure 
and  the  author's  belief  that  they  can  be  completely  cured  is  founded 
upon  the  marked  benefit  experienced  in  a  short  time  by  some  severe 
cases.  The  technic  suggested  is  the  glass  vacuum  electrode  with  a 
current  of  150  to  200  milliamperes  from  the  Oudin  resonator  for  ten 
minutes  three  times  a  week.  Of  course,  an  elastic  stocking  should  be 
worn  until  a  cure  is  effected. 

Ernest  Zueblin1  treats  acute  and  chronic  arthritis  by  the  electrodes 
connected  with  an  x-ray  coil  and  giving  a  form  of  wave  current. 

DIATHERMY,  OR  THERMOPENETRATION 

These  names  have  been  applied  to  the  application  of  high-frequency 
currents  of  many  hundred  milliamperes  or  even  over  an  ampere,  genera- 
ting a  great  deal  of  heat  in  their  passage  through  the  tissues  of  the  human 
body.  Their  frequency  must  be  about  a  million  oscillations  per  second 
in  order  to  avoid  sensory  and  motor  effects,  but  their  voltage  is  rela- 
tively low;  and  for  many  purposes  their  currents  .are  applied  by  metal 
electrodes,  either  ban1  or  covered  with  wet  cloth,  in  direct  contact  with 
the  surface  of  the  body. 

Thermopenetration  or  Diathermy. — Nagelschmidt  has  been  chiefly 
instrumental  in  developing  this  line  of  high-frequency  treatment.  Essen- 
tially, it  consists  in  the  application  of  high-frequency  currents  of  com- 
paratively low  voltage1  and  great  milliamperage,  and  very  often  em- 
ploys two  metal  electrodes,  with  or  without  a  covering  of  wet  cloth  and 
connected  with  the  ends  of  a  d'Arsonval  coil. 

The  original  d'Arsonval  high-frequency  apparatus,  with  two  elec- 
trodes applied  to  the  surface,  generated  a  demonstrable  amount  of  heat 
in  the  body. 

At  each  Leyden  jar  discharge  across  the  spark-gap  a  short  series  of 
exceedingly  rapid  oscillations  was  set  up.  which  very  quickly  died  out. 
just  as  the  vibration  of  a  guitar  string  may  be  arrested  by  the  pressure 
of  the  hand.  The  currents  flowed  for  only  a  small  fraction  of  the  time 
between  successive  discharges,  and  it  was  impossible  to  transmit  a  suffi- 
cient quantity  of  electricity  through  the. bodily  resistance1  without  using 
an  excessive  voltage. 

Three1  different  methods  are  available  for  producing  the  stronger 
currents  required  for  diathermy.  One  employs  an  ordinary  induc- 

1  New  York  MM.  Jour..  January  i_V,.  1<UX. 

-  !•".  Nuticlschiuidt,  Lchrbuch  <!<T  Diathermic,  1913. 


032  MK1MCAL    Kl.KCTKK'ITY    AM)    KOXTCKX    KAYS 

tion  coil  with  condensers,  D'Arsonval  solenoid,  and  a  scries  of  sometimes 
as  many  as  nine  very  short  spark-gaps.  This  results  in  a  very  rapid 
succession  of  discharges,  each  of  which  produces  its  series  of  damped 
oscillations.  The  apparatus  is  based  upon  the  Telefunken  Company's 
apparatus  for  wireless  telegraphy  and  is  very  effective. 

A  </i«'tich«l  xfHirk  is  one  in  which  the  hot  gases  are  immediately  re- 
moved and  the  current  flow  stopped,  just  as  an  ordinary  arc  may  be 
blown  out  by  a  strong  current  of  air.  Spark-gaps  with  such  a  character 
make  possible1  a  much  more  rapid  succession  of  sparks  than  when  the 
conductivity  of  the  hot  gases  defeats  the  very  object  of  the  gap.  This 
can  be  done  very  well  by  having  the  terminals  on  revolving  wheels,  so 
that  the  hot  gases  are  carried  away  mechanically  and  new,  cool  metal 
surfaces  are  constantly  presented.  A  spark-gap  of  this  character  could 
be  used  for  diathermy,  but  the  Telefunken  type  is  simpler  and  sufficiently 
effective.  Another  uses  a  !-.>  kilowatt  transformer  with  the  same  series 
spark-gap  condensers  and  d'Arsonval  solenoid.  These  two  methods 
produce  damped  oscillations,  differing  from  the  ordinary  high-frequency 
currents  in  having  lower  voltage  and  greater  milliamperage.  The 
third  method,  which  was  the  first  to  be  employed,  uses  the  undamped 
oxci[lii(i(»i*  produced  by  the  singing  arc  (page  h'40\  but,  instead  of  being 
applied  directly  to  the  patient  as  with  the  DeForest  needle,  the  current 
for  thennopenet ration  is  taken  from  the  two  ends  of  a  secondary  coil 
which  surrounds  the  self-inductance  of  the  singing  arc  circuit.  The 
direct  electric-light  current  supplies  a  current  of  about  (>  amperes  to  an 
arc  lamp  which  has  an  inductance  in  shunt  to  it.  The  current  becomes 
an  oscillatory  one,  and  the  arc  emits  a  musical  note'  from  the  rapid 
alternation  between  greater  and  lesser  expansion  of  the  hot  gases  between 
the  electrodes.  The  currents  supplied  to  a  patient,  also  in  shunt,  con- 
-i-t  of  undamped  oscillations  of  a  sufficient  frequency,  about  1,000,000 
per  second,  and  lasting  a  large  part  of  the  time  between  one  stronger  flow 
of  current  at  the  electrodes  and  the  next.  Theoretically,  this  seemed  to 
.-olve  the  problem,  but  it  was  very  soon  found  that  a  lack  of  uniformity 
in  the  operation  of  the  arc  lamp  of'fr-et  all  the  advantages  of  the  un- 
damped oscillations,  except  the  quantity  of  electricity.  Surrounding 
the  arc  with  an  alcohol  flame  improved  matters  somewhat,  and,  for 
certain  -uruical  applications,  this  is  a  satisfactorv  method  of  thermo- 


The  electrodes  for  diathermy  may  be  of  bare  metal  when  applied 
to  MIMIC  m-en-itive  ,-urface,  with  a  good  area  ot  contact,  as  when  the 
electrode-  ;ire  held  in  the  hands  and  sometimes  when  they  are  applied 
to  opposite  -ide-  of  a  limb.  Very  often,  however,  it  i-  bet  ter  to  cover  the 
electrode-  thickly  with  cloth  wet  through  and  through  with  a  weak  solu- 
tion of  .-odium  bicarbonate.  Diathermal  currents  are  also  applied  in 
auloeonden.-at  ion,  u>itm  the  same  large  iiiMilated  metal  .-heets  employed 
\\  it  h  the  d'Aix  nival  current.-. 

It  i-  e>-ential.  except  in  autocondensation,  that  there  >hall  be  a  good 
contact  when  'he  current  i-  turned  on  or  ott  and  during  the  entire  dura- 
tion of  it-  flow.  !  )i-reu-;ird  of  thi>  precaution  re-ult-  in  very  hot.  pain- 
ful -)>;irk-. 

The  effects  of  diathermy,  which  are  mo-t  important .  are  due  to  t  he 
production  ot  heat  in  the  ii--ue-  caused  \>\  the  -a me  ohmic  or  frictional 


HIGH-FREQUENCY    CURRENTS 

resistance  to  the  passage  of  a  current  of  great  milliamporage,  us  in  the 
ease  of  a  flatiron  heated  by  an  electric  current. 

If  electrodes  about  2  inches  in  diameter  are  applied  at  opposite 
sides  of  a  piece  of  raw  meat,  the  latter  may  bo  cooked  all  the  way  through 
along  a  direct  path  between  the  two  electrodes.  Placed  a  little  di.-tanco 
apart  upon  the  same  side  of  a  piece  of  meat,  the  latter  is  cooked  to  only 
a  certain  depth  between  the  electrodes.  Applied  to  opposite  sides  of  a 
patient's  joint  there  should  at  first  be  no  sensation:  if  there  is,  it  means 
that  the  contact  is  imperfect,  the  metal  not  completely  covered  by 
the  wet  cloth,  or  that  there  is  an  abrasion  of  the  skin  which  should 
bo  covered  by  adhesive  plaster,  or  that  the  current  is  too  strong,  or. 
more  often,  that  the  cloth  is  not  wet  all  the  way  through.  After  the 
proper  current  has  been  turned  on  for  a  very  few  minutes  a  sense  of 
warmth,  and  later  of  intolerable  heat,  develops  inside  the  joint.  The 
stage  of  marked  discomfort  is  an  indication  for  stopping  and  applying 
the  current  to  some  other  part  of  the  joint.  The  best  guide  to  the  right 
amount  of  current  for  local  use  is  the  sensation  of  the  patient,  and  one 
would  hesitate  to  apply  it  to  an  unconscious  person  or  one  with  sensory 
paralysis.  It  ought  to  feel  uncomfortably  hot.  but  not  really  painful. 
The  electrodes  nuixt  be  in  cloxe  contact  with  tin  */,•///  tchiie  the  current  is 
being  turned  on  or  off,  otherwise  very  hot.  painful  sparks  are  produced. 

A  thermometer  may  show  that  the  temperature  of  the  skin  at  the 
place  of  application  is  higher  than  the  normal  temperature  of  the  blood, 
and  animals  have  been  killed  by  the  application  of  2300  milliamperes 
for  an  hour.  There1  was  high  temperature  without  microscopic  lesions. 

The  therapeutic  importance  of  thermopenetration  lies  in  the  fact 
that  heat  is  developed  in  the  depth  of  the  tissues,  and  not  merely  upon 
the  surface,  as  with  ordinary  hot  applications.  The  beneficial  result  is 
from  an  increased  blood  and  lymph  circulation  and  increased  activity  of 
tissue  metabolism.  ( louty  deposits  often  disappear,  sciatica  and  other 
cases  of  neuritis  are  often  cured:  asthma  is  often  relieved  as  by  no  other 
electric  means.  Traumatic  and  inflammatory  swellings  and  deposits 
are  benefited.  ( Jonorrheal  rheumatism  is  benefited  by  a  bactericide 
action  of  the  high  temperature  produced  inside  the  joint. 

Nagelschmidt's  autocondensation  couch  for  diathermic  currents  is 
of  wood  with  a  metal  plate  under  and  a  hard-rubber  plate  over  it:  and 
entirely  covering  the  patient  is  a  flexible1  sheet  of  metal  netting  with  a 
flexible  rubber  covering.  Schittonhelm's  is  like  the  one  used  by  the 
author  ( page1  60S). 

Monopolar  applications  of  diathermic  currents  are  made  with  the 
same  condenser  electrodes  (glass  vacuum  electrodes  and  glass  or  hard 
rubber  electrodes  filled  with  graphite),  as  for  ordinary  high-frequency 
currents,  and  also  with  the  same  eflluvers. 

Bipolar  applications  of  diathermic  currents  sometimes  employ  one 
or  more  large  metal  cylinders  to  be  held  by  the  patient,  but  very  com- 
monly metal  plates  of  a  nature  to  be  somewhat  moulded  to  the  surface, 
-till  with  sufficient  rigidity  to  allow  of  firm  pressure  being  exerted  by 
a  wooden  handle  or  by  a  bandage.  Some  plate  electrodes  include  a 
resistance  thermometer,  connected  with  a  separate  electric  apparatus, 
which  indicates  the  temperature  attained  at  the  place  of  contact  with 
the  skin.  (  M  hers  are  made  with  an  insulated  backing,  and  the  tempera- 
ture mav  be  determined  bv  touching  with  the  finger.  Six  thicknesses 


034  MKDICAL    KLKCTHK  ITY    AND    RONTOEN    KAYS 

of  \vct  gauze  form  a  suitable  covering  for  the  electrodes.     Water  elec- 
trodes, like  the  shallow  four-cell  hath,  are  sometimes  useful. 

The  marginal  effect,  which  is  to  he  avoided,  is  a  concentration  of  the 
current  when  two  electrodes  are  close  together  and  the  skin  is  unduly 
heated  at  the  closest  points. 

Special  Effects  of  Diathermy. — There  is  no  electrolysis  in  the  ordi- 
nary polari/ation  sense,  and  the  tolerance  of  the  tissues  to  warmth  is  the 
only  limit  to  the  strength  of  the  current.  In  transverse  penetration  the 
greatest  rise  of  temperature  occurs  in  the  skin,  less  in  the  hone,  muscle, 
fat,  and  least  in  nerve.  In  longitudinal  or  parallel  conduction  the  condi- 
tions are  exactly  reversed.  In  the  use  of  the  atitocoiiduction  cage  the 
current  traversing  the  solenoid  is  measured  by  a  hot-win1  milliampere- 
meter,  between  one  pole  of  the  generator  and  one  terminal  of  the  sole- 
noid. Xo  important  rise  of  temperature  occurs  in  the  body.  A  small 
solenoid,  through  which  passes  a  high-frequency  current  of  10  or  12 
amperes,  warms  an  arm  held  inside  it,  and  a  ball  of  tin-foil  becomes  hot 
instantly  and  will  melt  in  a  few  seconds.  A  finger-ring  becomes  danger- 
ously hot. 

In  both  autoconduction  and  autocondensation  the  therapeutic  effect 
of  diathermic  currents  is  due  to  the  heating  of  the  body. 

With  bipolar  electrodes  300  or  400  ma.  or  more  causes  art  ('rial  hyper- 
emia  of  the  skin  \vith  reflex  stimulating  effects,  such  as  perspiration 
and  a  sense  of  heat.  There  is  a  sedative  effect  upon  itching  or  pain  and 
also  a  derivative  effect,  as  well  as  a  temporary  increase  in  blood-pressure 
consequent  upon  skin  irritation. 

The  regular  bipolar  diathermy  produces  no  motor  or  sensory  effect 
except  thai  of  warmth.  The  skin  and  blood  and  living  bone  are  chiefly 
wanned.  The  local  temperature  is  raised  by  therapeutic  applications 
of  40°  or  4.">°  ('.  Higher  temperatures,  even  45°  to  ~)(f  ('.,  which  are 
below  the  temperature  of  coagulation,  may  injure  the  tissues  by  prccipi- 
tat  inir  globulin.-.  A  tempera!  ure  of  S()°  ( '.  coagulate-  albumen  and  sepa- 
rate.- llie  skin  into  two  layers,  a  blister  externally  and  leathery  beneath. 
l>oiie  retain-  its  consistence,  and  the  other  tissues  form  a  soft  coagulum 
removable  with  a  sharp  spoon.  The  final  effect  is  complete  carboni/a- 
t  ion. 

The  wcoiiddri)  pfn/xioloyic  r//Vr/N  of  (lidthcrniy  result  from  increased 
cellular  activity  from  warmth  reaching  the  intimale  structure  of  differ- 
ent organs.  Dialhermy  through  the  hear!,  with  the  active  electrode 
over  the  .-lernum.  in  therapeutic  doses  in  healthy  animals,  increases  the 
pulse-rate  and  raises  the  blood-pressure  temporarily  without  any  effect 
on  the  respiration.  Transversely  through  the  chest  there  is  a  similar 
ettect  upon  respiration,  but  HOIK*  upon  the  circulation.  A  condenser 
application,  as  from  a  glass  vacuum  electrode,  raise-  the  general  blood- 
pre-.-ure  by  -l  imulat  ing  the  surface  vasoconstrictors.  Diathermy 
through  the  body,  as  by  the  four-cell  bath,  lower-  the  blood-pressure 
bv  relaxat  ion  of  t  he  -plan clinic  vasomotors,  and  t  he  same  is  true  to  some 
extent  with  autoconduction  and  autocondensation. 

'1  he  local  etled  of  diathermy  by  contact  application  is  evidenced  by 
an  experiment  of  Nagelschmidt.  An  incision  in  which  hemorrhage 
ha-  been  .-topped  hy  pressure  begin-  to  bleed  freely  if  diathermy  is  ap- 
plied from  elect  rode-  at  eit  her  side  of,  but  at  a  distance  from,  the  incision. 
After  an  ordmarv  treatment  the  place  of  application  remains  hyperemic 
considerably  lonuer  than  if  the  electrode  had  been  pressed  upon  the  skin 


HKiH-FHEQUENCY    CURRENTS  035 

without  any  current,  and  for  quite  a  while  afterward  the  skin  is  hyper- 
sensitive and  in  a  dermographic  condition.  Another  of  his  experiments 
shows  that  diathermy  of  a  part  of  a  forearm  in  a  blue  condition  from 
Bier's  hyperemia  will  become  a  bright  arterial  reel  on  the  application  of 
a  diathermic  current. 

The  effect  of  these  currents  upon  nerves  is  to  produce  a  sense  of 
warmth,  and  also  to  stimulate  those  which  are  distributed  to  glandular 
organs  and  increase  the  secretion  of  the  latter.  The  effect  upon  the 
vasomotor  and  cardiac  and  respiratory  nerves  has  already  been  referred 
to,  and  so  has  the  lack  of  effect  upon  motor  nerves  by  the  currents  and 
the  very  great  effect  by  the  spark.  The  indirect  high-frequency  spark, 
applied  to  a  metal  electrode  already  in  contact  with  the  skin,  is  exceed- 
ingly active  in  exciting  muscular  contraction,  and  is  a  valuable  improve- 
ment upon  galvanic  and  faradic  currents  for  this  purpose.  The  effect 
of  diathermy  through  the  brain  is  to  produce1  a  sensation  of  compression, 
which  passes  off  as  soon  as  the  current  is  stopped.  Diathermy  increases 
the  secretion  of  the  thyroid  gland. 

Kxcept  for  the  gonococcus,  which  is  killed  by  a  very  slight  rise  of 
temperature,  diathermy  cannot  be  depended  upon  as  a  bactericide  in  liv- 
ing tissues;  in  fact,  it  is  sometimes  doubtful  whether  or  not  these  cur- 
rents may  actually  increase  the  vitality  of  the  germs  as  well  as  that  of 
the  tissue  cells  in  certain  diseases. 

The  strength  of  current  to  be  applied  bears  a  certain  relation  to  the 
size  of  the  electrode,  to  the  diameter  of  the  limb  when  the  current  must 
traverse  its  length,  and  to  the  nature  of  the  internal  organs  traversed. 

Strength  of  Diathermic  Current  and  8ize  of  Electrode*  for  Bipolar  Application 

(After  Xagelschmult) 
Electrodes.  Milliutnperes. 

Hand  to  hand ' ! 3f>0  to    500 

Foot  to  foot ")()()  to     TOO 

2  cm.  (  [*u-  inch)  diameter 1~>0  to    200 

4  cm.  (1T-,T  inch)  diameter 300  to    400 

*)  cm.  C5,'1,  inch)  diameter 900  to  1000 

10  by  12  cm.  (4  by  8  inches) about    2000 

If  the  skin  becomes  too  hot  before  the  treatment  is  finished  the  cur- 
rent may  be  turned  off  and  the  electrodes  dipped  in  cold  water.  The 
patient's  sensations  should  not  be  taken  as  the  sole  guide,  because  some- 
times a  degree  of  tolerance  is  established  to  currents  strong  enough  to 
blister  the  skin. 

The  duration  of  the  application  usually  varies  from  three  or  four  to 
ten  or  fifteen  minutes. 

The  application  rctjuirex  expert  attention  even,  moment  of  the  time, 
and  should  not  be  entrusted  to  a  nurse  or  an  untrained  physician.  There 
is  the  danger  of  overheating  the  surface  tissues,  and  faintness  or  col- 
lapse from  tin1  passage  of  too  strong  a  current  through  the  heart  or  the 
brain. 

Diathermy  in  Circulatory  Diseases. -The  conditions  in  which  the 
treatment  is  chiefly  useful  are  classified  by  Xagelschmidt  as  high  arterial 
tension,  relaxation  of  peripheral  vessels,  cardiac  hypertrophy,  cardiac 
dilatation. 

Anomalies  of  Khi/thm  atnl  Frcf/Hcnci/.—  A  large  electrode  is  applied 
between  the  shoulder-blades  and  another  over  the  front  of  the  chest. 


MKD1CAL    KI.K<  TKK   1TY    AM)    HONTCKN     KAYS 

This  stimulates  the  heart  muscle  and  relaxes  spasm  in  the  coronary 
arteries,  and  is  useful  in  cases  of  myocardial  degeneration,  some  valvular 
lesions,  and  angina  pectoris.  Aneurysm  of  the  aorta  shows  subjective 
improvement,  and  a  case  of  coronary  disease  which  resists  treatment  by 
diathermy  is  regarded  by  Xagelschmidt  as  indicative  of  beginning  aortic 
aneurysm.  Arteriosclerosis  of  the  brain  is  treated  by  a  bipolar  applica- 
tion or  by  a  small  solenoid  surrounding  the  head.  Local  asphyxia, 
intermittent  claudication,  and  Raynaud's  disease  are  all  treated  by  a 
bipolar  application. 

Kflluves  and  condenser  applications  are  indicated  in  low  arterial 
tension  from  relaxation  of  the  peripheral  arteries,  and  I  have  obtained 
remarkable  results  in  cases  of  phlebitis. 

\\  .  Martin1  in  a  case  of  pseudo-angina  pectoris  used  a  ^  x  4  inch  metal 
electrode  in  front,  and  one  measuring  4  x  f)  inches  near  the  spine  at  the 
-ame  level,  applied  thermopenetration,  SOO  ma.,  for  thirty  minutes. 
\  ibration  was  applied  at  the  seventh  cervical  and  first  dorsal  interspace*, 
alternating  with  percussion.  Also  for  intestinal  stasis  a  slow  surging  sinu- 
soidal current  was  applied  from  front  and  back  electrodes.  Later  neuritis 
of  the  shoulder  was  tested  by  the  static  wave  current,  and  ?,-inch  gap 
caused  pain,  so  the  same  was  used  for  treatment,  also  indirect  sparks. 
I  )e  Kraft  considers  painful  muscular  cramps  in  elderly  people  as  due  to 
local  arteriosclerosis,  and  reports  great  benefit  from  diathermy,  very 
mild  at  tir-t.  applied  by  small  disk  electrodes. 

Diathermy  in  Respiratory  Diseases.-  The  bipolar  application. 
through  the  chest  from  side  to  side,  is  excellent  in  acute  and  chronic 
bronchitis  and  pleurisy,  and  applied  at  the  upper  and  lower  extremities 
of  the  sternum  it  is  a  specific  in  asthma.  It  often  has  a  beneficial  effect 
in  pulmonary  tuberculosis,  but  sometimes  causes  an  exacerbation  and 
had  probably  better  be  combined  with  the  .r-ray  in  this  disease. 

Diathermy  in  Other  Internal  Diseases.-  Applied  to  the  kidney  in  a 
number  of  different  diseases  it  increases  not  only  the  water  but  also  the 
solids  of  the  urine,  pathologic  or  normal,  and  eventually  leads  to  a 
healthy  activity  and  seems  to  be  indicated  in  chronic  Bright 's  disease, 
where  it  -eems  likely  to  afford  a  means  of  more  permanent  relief  than 
the  opeiation  of  decapsulation.  It  is  especially  indicated  in  cases  of 
hiirh  arterial  tension  when  the  primary  cause  lies  in  the  kidneys.  It  is 
of  the  same  doubtful  value  in  bacterial  diseases  of  the  kidney  as  of  the 
luni:.  1  )e  Kraft  quotes  ("arro"  regarding  gastric  ulcer.  Three  cases 
twenty  or  t  hirty  minute-  daily  for  a  course  of  eight  tot  went  v  t  reatments. 
<  MJC  case  of  dysenteriform  colitis  of  ten  years'  -landing  showed  very 
•ults.  I  )e  Kraft  counsels  caution  because  of  the  danger  of 
but  agree-  with  Fur.-tenberg  Scheme!  that  two  S  x  10  inch 
electrodes,  one  over  the  back  and  one  over  abdomen,  produce  a  higher 
temperature  in  interior  of  the  stomach  with  i>00  ma.  than  with  2000 
ma.;  I  )e  Kraft  think-  strong  currents  excite  reflex  surface  action  which 
may  protect  the  interior  and  relieve  engorgement  of  it  instead  of  causing 
iivperemia.  l)iathermy  ha-  an  excellent  effect  in  colitis,  intestinal  ad- 
he-ions.  and  chronic  appendicitis,  but  will  aggravate  the  latter  disease 
if  -uppurat  ion  i-  p  re-en  t.  This  may  be  excluded  by  a  count  of  t  he  white 
I'll  la  r\  and  renal  colic  a  re  benefited,  except .  of  course,  cases 


\tn>]    .I"-:     Kli    tpithcnipy  Mini    R;ii!i<>l<ijry.  vol. 
. 

M.    :  '•  •  '       M.'MJrirl     Murdi.  7  I'.MX. 


HKiH-FKKQrKNCY    CTUKKN'TS  h'37 

requiring  operation.  Achylia  gastrica  is  benefited,  hut  the>  oppeisite 
condition  of  hyperacidity  is  ml  her  a  contraindication,  because  of  the 
possibility  of  a  latent  ulcer  which  would  be  aggravated  by  diathermy. 
Nervous  gastralgia,  dyspepsia,  and  disturbances  of  mot ility  are  benefited. 
Xagelschmidl  distinguishes  the  cases  of  exophthalmic  goiter  due  to 
hyposecretion,  and  which  should  be  treated  by  diathermy,  from  those 
due  to  increased  secretion  and  which  should  be  treated  by  the  .r-ray.  A 
single  test  administration  of  iodid  aggravated  a  case  calling  for  dia- 
thermy. Hypert hvroidism  is  benefited  by  tincture  of  iodin,  nyij,  in 
a  little  milk  a  half-hour  before  meals,  increased  to  itpiij  or  v.  Hypo- 
thyroidisin  is  aggravated  by  iodin. 

Diathermy  in  Gynecology.^  The-  best  results  are  from  a  large  indif- 
ferent external  electrode  and  an  active  vaginal  electrode.  Suppurative 
processes  are  a  contra-indication,  but  outside  of  them  the  current  is  of 
the  greatest  value  in  adhesions,  uterine  displacements,  old  exudates,  and 
ovarian  neuralgia.  A  strong  application  tot  he  entire  mucous  membrane 
of  the  uterus  is  advised  in  acute  or  chronic  gonorrhea!  endometritis. 
Sterility  from  infantilism  is  an  indication  for  this  treatment. 

Genito-urinary  Diseases  in  the  Male.— Gonorrhea  is  curable,  but 
thi1  application  is  by  no  means  a  simple  one.  A  special  electrode,  with 
a  temperature  indicator,  must  be  used  which  will  reach  each  portion  of 
the  urethral  mucous  membrane  in  turn  and  raise  the  temperature  of  the 
tissues  to  4)U°  or  46°  C.  Santos  has  succeeded  in  producing  a  complete- 
cure  in  a  single  application,  lasting  ninety  minutes.  Chronic  gonorrhea! 
areas  and  indurations  and  strictures  are  all  curable  by  the  same  current 
applied  in  the  urethra.  Incontinence  of  urine  as  a  symptom  of  sexual 
neurasthenia  is  treated  by  diathermy  intra-urethrally  if  possible,  and. 
otherwise,  with  one  electrode  in  the  rectum  and  the  other  on  the  peri- 
neum. Impotence  of  a  psychic  type  yields  to  bipolar  diathermy  of  the 
penis,  scrotum,  and  perineum,  and,  if  due  to  hypo-esthesia  of  the  glans, 
the  condenser  application  of  a  glass  vacuum  electrode  rubbed  over  the 
surface1  is  exceedingly  effective.  1  have  had  a  number  of  cases  in  which 
the  application  of  a  strong,  hot  current,  but  with  a  good  contact,  so 
as  to  avoid  a  spark  effect  from  the  glass  vacuum  electrode,  has  produced 
the  most  vigorous  erections  during  the  application  and  the  most  gratify- 
ing results  after  a  course1  of  treatments.  Other  cases  have  responded  to 
the  first  applications,  and  have'  shown  a  diminishing  effect  from  the  sub- 
sequent ones  and  the  impotence  has  remained:  a  guarded  prognosis 
should,  therefore,  be  given.  Acute  prostatis  should  not  be  treated  by 
diathermy,  but  chronic  prostatitis  and  prostalic  hypertrophy  arc1  bene- 
fited by  it.  Xagelschmidt  advises  energetic  bipolar  diathermy  in  every 
case  of  acute  epididymitis  and  funiculitis,  in  which  he  says  it  is  extra- 
ordinarily successful  if  applied  long  enough  and  strong  enough,  and  ha> 
the  greatest  tendency  to  prevent  occlusion  of  the1  seminal  ducts.  Too 
weak  or  too  short  applications  only  aggravate1  the1  condition. 

Diathermy  in  Joint  Diseases. —  The1  bipolar  contact  method  is  used 
and  a  sense1  of  warmth  should  be1  felt  in  the  joint  itself.  1  have1  seen 
gouty  deposits  disappear  from  the'  finger-joints  undeT  this  tivatment. 
and  it  is  effective1  also  in  many  other  forms  of  acute'  and  chronic  arthriti- 
and  in  tenosynovitis. 

Among  diseases  of  the  nervous  system  >ciatica  is  treated  succe<- 
fully  by  e-neM'getic  diathermy  of  each  separate  part  of  the  nerve,  but.  ot 
course,  the1  effee-t  will  be  only  palliative'  if  the  pain  is  secondary  to 


(io8  MEDICAL    ELECTRICITY    AND    KONTCEN    HAYS 

disease  of  some  internal  organ  which  remains  undiscovered  and  un- 
treated. Supra-orbital  neuralgia  and  many  others  are  cured.  The 
result  in  herpes  /.oster  is  more  uncertain.  Trigeminal  neuralgia  some- 
times yields  to  heavy  diathermic  currents  applied  externally,  and  in 
some  of  the  cases  in  which  this  has  failed  Nagelschmidt  has  made  an 
exceedingly  valuable  observation.  He  finds  that  in  these  cases  the 
attacks  of  pain  are  excited  by  any  contact  or  change  of  temperature  or 
movement  of  the  mucous  membrane  of  the  mouth,  and  that  this  hyper- 
esthesia  can  be  cured  by  the  application  of  a  vacuum  electrode  to  every 
part  of  the  mucous  membrane.  Very  weak  currents  have  to  be  used  at 
first,  as  the  application  itself  may  bring  on  an  attack  of  pain;  then 
stronger  and  stronger  currents.  During  a  ten  or  fifteen  minute1  applica- 
tion the  current  must  lie  turned  off  several  times  and  the  glass  electrode 
cooled.  Chorea  minor  in  children  may  be  cured  by  diathermy.  S.  C. 
Damoglous1  treated  2  cases  of  recent  hemiplegia  supposed  to  be  due 
to  cerebral  embolism  by  general  diathermy.  He  reports  complete  re- 
covery. 

An  important  application  of  diathermy  is  in  the  treatment  of  loco- 
motor  nta.ria.  Improvement  takes  place  in  a  great  majority  of  cases, 
chiefly  in  the  lightning  pains,  the  hyperalgia,  and  the  incontinence. 
The  patient's  general  condition  is  also  better.  My  experience  has  not 
led.  however,  to  the  belief  that  a  cure1  for  the  disease  has  been  discovered. 
General  treatment  by  the  vacuum  electrode  is  important.  The  effhive 
is  suitable  for  the  lancinating  pains  and  the  vacuum  electrode  for  the 
girdle  sensation.  The  latter  application  is  to  be  very  weak  at  first,  but 
gradually  increased  on  different  occasions.  Some  cases  which  are  not 
benefited  by  weak  are  by  very  strong  applications.  Small,  very  painful 
areas  are  treated  by  the  bipolar  contact  application,  which  may  at  first 
employ  electrodes  at  opposite  sides  of  the  painful  area  in  cases  where 
direct  contact  would  excite  pain.  Gastric  crises  yield  to  the  efrluve. 
Vesical  crises  are  treated  with  a  metal  catheter  in  the  bladder  full  of 
water  and  an  indifferent  electrode  held  in  the  patient's  hand  and  a  dia- 
thermic current  of  50  to  100  ma.  By  a  course  of  treatment  of  this  kind 
the  muscular  tone  of  the  bladder  and  of  the  sphincter  may  be  restored, 
although  sensation  and  the  normal  impulse  to  urinate  are  still  lacking. 
The  patient  is  directed  to  urinate  every  three  hours,  and  is  enabled  to 
almost  or  quite  empty  the  bladder.  Another  effective  application  is 
with  a  higher  voltage  and  indirect  sparks;  an  indifferent  electrode  is  held 
in  the  hand  or  upon  the  lower  part  of  the  abdomen,  another  metallic 
electrode  extend-  into  the  bladder,  and  sparks  are  applied  to  its  external 
end.  This  last  treatment  is  also  applied  to  the  rectum  for  lack  of  mus- 
cular lone.  Painful  art  hropat  hies  are  benefited  by  energetic  bipolar 
dial  hermy. 

Diathermy  as  Means  of  Epilation. —  It  has  t  he  advantage  of  requiring 
only  a  second  to  destroy  a  hair  bulb  and  requires  a  very  small  amount  of 
<  'ne's  apparatus  may  be  such  that  the  weakest  current  is  too 
i\\}\  by  action  along  the  entire  length  of  the  needle  in  the 
if  merely  at  the  point,  and  coagulation  and  perhaps  a  little 
In   tlii-  case  a  water  resistance  may   be  used  to  reduce  the 

i  if  current . 

of  a   chronic  type  recurring  in   the  same  spot    may  be  treated 
nic  current   applied   through  a  needle. 

iur.   Kli-ftrotlii-rujiy  ami   Hitdinlo^y,  vol.  \x\vi,   No.  .'>.  June,  19 IS,  p. 
175. 


HIGH-FREQUENCY    CURRENTS  039 

Warts  are  treated  in  the  same  way,  and  the  test  of  complete  coagula- 
tion is  that  the  wart  has  become  entirely  movable  upon  the  underlying 
tissues.  No  anesthetic  is  required,  and  as  many  as  thirty  have  been  re- 
moved at  one  sitting. 

Xanthelaxma  has  often  been  permanently  removed  in  this  way  by 
Xagelschmidt.  The  weakest  diathermic  current  is  used  and  the  needle 
should  enter  a  little  beyond  the  yellow  area.  The  patient  should  be  in- 
formed that  some  edema  of  the  eyelid  will  occur,  but  will  not  do  any 
harm. 

In  all  these  cases,  and  also  in  small  papillomata,  fibromata,  athero- 
mata,  and  cysts  the  patient  holds  an  indifferent  electrode  in  his  hand 
and  the  needle  is  inserted  before  the  current  is  turned  on. 

For  small  superficial  telangiectases  the  needle  is  not  to  puncture  the 
blood-vessel,  but  just  to  be  pressed  against  the  surface  during  the  second 
that  the  current  flows.  There  should  be  enough  space  between  the 
several  points  treated  to  prevent  the  confluence  of  the  little  sores 
caused  thereby. 

Surgical  diathermy,  in  its  different  forms,  employs  very  much  stronger 
currents  than  the  above,  and  is  described  elsewhere  (page  640).  An 
important  method  is  a  bipolar  application  of  low  tension,  high-frequency 
currents  of  sufficient  milliamperage  to  coagulate1  and  devitalize  the 
tissues  in  the  neighborhood  of  the  active  electrode  or  electrodes.  The 
maximum  high-frequency  current  required  is  400  volts  and  2  or  3  amperes. 
For  most  purposes  both  electrodes  are  active  and  are  thrust  into  the 
tissue  to  be  destroyed,  but  for  some  delicate  work  there  is  one  large  indif- 
ferent electrode  and  another  small  active  one.  The  effect  is  one  of  co- 
agulation-necrosis. The  heat  sterilizes  the  eschar,  which  may  be  left 
to  separate  naturally,  or  may  be  cut  away  if  the  operation  must  be  carried 
deeper  into  the  tissues.  This  is  better  than  thrusting  the  electrodes  so 
deeply  into  the  tissues  that  the  effect  cannot  be  observed.  There  is  no 
hemorrhage.  Many  varieties  of  tumors  are  treated  by  diathermy,  and  it 
is  said  to  be  very  much  the  best  means  of  operating  upon  hypertrophied 
tonsils.  It  is  suitable  for  some  inoperable  cases  of  cancer,  and  some- 
times as  a  preparation  for  an  operation  by  closing  the  lymphatics  and 
lessening  the  danger  of  absorption  from  the  cut  surface.  Hemorrhoids 
and  large  or  small  benign  as  well  as  malignant  tumors  may  be  treated 
in  this  way. 

Prostatic  obstruction  due  to  small  growths  of  various  kinds  has 
been  successfully  treated1  by  the1  direct  application  of  high-frequency 
currents  by  a  wire  passed  through  a  cystoscope.  The  wire  is  insulated, 
except  for  an  extremity  of  ',  inch,  which  is  pressed  against  the  tissue  to 
be  destroyed  or  cut  through. 

Technic  of  Diathermy  for  Hemorrhoids. — This  is  suitable  for  large* 
bleeding  internal  ones.  Move  bowels.  Allow  hemorrhoids  to  pro- 
trude. Cocainize.  A  large'  dispersive  electrode  is  under  the  patient's 
side.  A  small  active  electrode1  is  applied,  and  the1  henmrrhoid  is  held 
with  forceps  if  there  is  a  tendene'v  to  recede.  Turn  on  e-unvnt  slowly 
until  patient  says  it  is  hot:  turn  off  instantly.  Current  about  oOO  ma. 
Apply  several  time's  to  eliflVivnt  aspects,  illumphris,  "Electrothera- 
peutics.") 

Electrocoagulation,  employee!  by  Doyen  and  others  as  a  preliminary 

1  Henry  ('. .  Bimbee.  New  York  State  Journal  of  Medicine,  vol.  xiii,  Xo.  S,  August, 
1913,  p.  410. 


1)40  MKIMCAL    KU-XTHU  ITY    AM)    R(">XT(iKN    HAYS 

to  excision  of  uterine  and  other  cancers,  may  have  one  small,  active, 
possibly  puncturing  electrode,  and  a  large  indifferent  electrode  or  two 
small  active  electrodes.  In  either  case  the  thermopenetration  current  is 
used,  and  the  tissues  are  fairly  cooked  before1  they  are  cut  with  the  knife. 
Dissemination  through  the  lymph-channels  and  blood-vessels  is  pre- 
vented. 

Win.  L.  Clark1  successfully  treats  hypertrophied  tonsils  by  high- 
frequency  desiccation  when  surgical  removal  is  impracticable  and 
especially  when  a  part  only  of  the  tonsil  requires  destruction.  Too 
hot  a  current  is  painful  in  spite  of  local  anesthesia:  it  burns  the  tissues 
instead  of  desiccating  them  and  tends  to  produce  cicatrical  contraction. 
There  must  be  no  air  space  between  the  metal  point  and  the  tonsil. 
There  is  no  smoke  or  odor  of  burning  flesh,  but  steam  is  seen  rising  from 
the  tissues.  The  correct  depth  of  action  is  obtained  by  gradually  push- 
in  ii  the  point  into  the  tonsil;  200  or  300  ma.  is  possible  in  this  way. 

Undamped  Oscillations,  Duddell's  Singing  Arc,  and  the  DeForest 
Needle.-  High-frequency  currents  with  damped  oscillations  are  analo- 
gous to  the  quickly  suppressed  oscillations  of  a  tuning-fork  in  water, 
while  the  long-continued  series  of  oscillations  of  uniform  extent,  when 
only  the  obstruction  of  the  air  is  encountered,  gives  a  better  idea  of 
undamped  oscillations.  One  use1  of  these  oscillations  is  in  connection 
with  the  DcForcxt  needle  or  cold  cantcri/.  This  is  like  a  small  platinum 
blade,  which  has  a  handle  insulated  by  glass  or  hard  rubber.  The  direct 
electric-light  current  passes  through  an  arc  lamp  in  which  the  electrodes  are 


Fin.  'MX.  -DcForcst    i 

broad  and  close  together;  the  electrodes  of  the  lamp  are  connected  with 
a  -elf-inductance  and  a  condenser.  Mewed  in  a  revolving  mirror,  the 
arc  liu'ht  may  be  seen  to  fluctuate  with  the  alternate  charge  and  dis- 
charge of  the  condenser;  these  oscillations  are  superimposed  upon  the 
direct  current  forming  the  arc,  and  the  alternate  greater  and  less  heating 
of  the  aii'  may  produce  a  musical  note  [Duddell's  singing  arc).  The 
1  oscillatory  current  free  from  the  direct  current  may  be  taken, 
:  a  monopol;ir  discharge,  fn  tin  eit  her  end  of  t  he  self-inductance. 
•  insulated  wire  carries  this  current  to  the  DeForest  needle, 
•lit  has  oscillations  of  the  usual  high  frequency,  but  of  very 
!<•.  ii-u.-iHy  not  more  than  100.  No  long  sparks,  therefore,  can 
t  lie  needle  to  t  he  pat  ient .  The  needle  itself  remains  cool,  while 
ers  much  li'reater  resistance  in  the  tissues,  which  are 
In  one  met  hod  it  does  not  touch  the?  surface,  but  is 
mil  Ha'linlouy,  vol.  \\xvi,  No.  <»,  September, 


HICH-FKMQrKXCY    (TKHKNTS  (i 41 

drawn  along  a  straight  line  near  t  he  surface,  the  sharp,  Iio1 .  almost  noise- 
less spark  cuts  the  flesh  like  a  knife  and  leaves  a  clean  red  surface,  nol 
charred  or  blackened,  but  without  any  capillary  hemorrhage.  The  cut 
surface  is  sterile.  This  makes  an  ideal  method  for  many  sorts  of  surgical 
cutting,  incising  abscesses,  and  especially  excision  of  tumors,  where  it 
has  the  great  advantage  over  the  knife  that  it  seals  the  capillaries  and 
lymphatics  against  infection  from  the  tumor  elements.  It  is  not  suited, 
however,  to  such  work  as  freeing  a  nerve  or  a  tendon  from  adhesions. 
It  would  not  be  a  desirable  means  of  operation  upon  an  artery. 

The  other  application  of  the  DeForest  needle,  by  which  it  is  plunged 
into  the  tissues,  produces  a  regular  coagulation-necrosis  of  greater  or 
less  extent ,  depending  upon  the  dept  h  to  which  t  he  needle  penet  rates  and 
the  length  of  time  for  which  the  current  is  applied.  It  is  suited  to  the 
destruction  and  sterilization  of  a  tumor  of  any  size  or  nature.  The 
entire  outfit  may  be  portable. 
41 


PHENOMENA  ACCOMPANYING  THE  TRANSMISSION  OF 
ELECTRICITY  THROUGH  GASES 

IT  is  only  static  or  other  very  high-tension  electricity  which  can  be 
transmit  ted  through  gases,  and  the  general  consideration  of  the  subject 
may  be  entered  upon  at  this  place.  Under  ordinary  conditions  the  air 
or  any  other  gas  in  contact  with  a  charged  body  does  not  become 
charged  and  is  not  a  conductor  of  electricity.  If  it  did  so.  of  course1,  the 
body  would  soon  lose  its  charge  by  a  process  of  convection;  each  por- 
tion of  the  air  as  it  became  charged  being  repelled  and  giving  place  to 
another  portion,  whi'-h  would  in  turn  take  away  a  certain  portion  of  the 
charge.  Since  gases  do  not  ordinarily  become  charged  in  this  way.  it 
is  interesting  to  note  some  of  the  ways  in  which  it  can  be  accomplished 
and  in  which  they  can  be  rendered  conductors  of  electricity. 

(lases  in  contact  with  the  surface  of  liquids  in  which  splashing  or 
even  quiet  waves  occur  become  electrified.  One  of  the  practicable 
forms  of  static  machine  is  dependent  upon  the  charge  acquired  by  a 
jet  of  steam.  These  are  some  of  the  ways  in  which  a  gas  ma}'  be  ionized, 
a  condit  ji  m  which  will  be  explained  later. 

<  Mher  means  of  ionixing  gases  and  rendering  them  capable1  of  receiv- 
ing and  transmitting  electricity  are  of  greater  interest  in  electrotherapy, 
annum  them  are  especially  exposure  to  the  r-niy.  the  ultraviolet  ray, 
and  some  of  the  rays  from  radio-active  substances,  also  by  the  passage 
of  a  spark  from  an  induction-coil.  This  is  the  \\av  in  which  the  current 
i-  started  through  the  mercury  vapor  in  some  forms  of  the  Cooper 
I  lewit  t  and  similar  lamps. 

IONIZATION  OF  GASES 

By  some  one  of  t  he  above  processes,  or  of  several  others  which  might 

be   mentioned,   some  of   the   molecules  oi    the   gas   are   dissociated   into 

positively  and  negatively  charged  ions.      An  excess  ot  positive  ions  in  a 

f  course,  cause  the  "-as  to  have  a  char^-  of  positive  electricity. 

\n  exampl'    of  the  way  in  which  this  may  com''  about    is  seen  when  a 

tras  becomes  electrified   by   contact    with   an    incandescent    metal  or  by 

the  pa-'saLrc  of  an  electric  arc  through   it.      In   consequence  of  the  high 

tempe]  itiin-  some  of  the  molecules  of  the  ira.-  become  dissociated  into 

positive   and    negative    ions.      SOUK-   of   these    combine   with    the   incan- 

de-ci  nt   met;       ,     with  the  terminals  of  the  arc.      In  the  resulting  com- 

llie  electropositive  element    and    will    take  negative 

•      'r  '     _ra-   and  leave  the  latter  with  an  excess  of  positive  ions. 

The   Atom   According  to   Sir   J.   J.   Thomson.      It    is   composed   of 

electroi  -      •  live  particle-  grouped  in  approximately  co-planar  and 

and   in  active  revolution,   the  >vstem   heimr  within  a 

-phere  oi  >  iectricity.      The   number  of  electrons  in  an  atom   is 

ited    to   ti  I  hues   its  atomic    weight  .' 

/'-/       are  '".MM!    by    electrons    which    are    -nppo-ed    to    be 

II      \     \\  ll-.,li,    I'l.ll.    M:,-   .   \\1,   p.   7K    I'.M  I. 


TRANSMISSION    OF    ELECTRICITY    THROUGH    OASES  043 

-joV<»  about  the  size  of  a  hydrogen  atom.  A  positive  ion  is  a  group  of 
particles  surrounding  a  positive  charge;  a  negative  ion  is  a  group  of 
particles  around  an  electron.  In  a  vacuum  tube  such  as  an  r-ray  tube, 
electrons  travel  at  an  average  rate  of  20,000  miles  a  second,  and  under 
certain  other  conditions  they  may  travel  as  fast  as  oO, ()()()  miles  a 
second.  Xo  matter  how  complex  the  chemic  formula  of  a  gas  may  be, 
each  ion  is  usually  a  particle  of  one  or  other  of  the  single  elements  which 
make  up  the  gas. 

The  ionizution  of  a  gas  by  the  ultraviolet  ray  takes  place  only  when 
the  light  is  reflected  from  a  fluorescent  substance  or  from  the  surface 
of  a  metal  immersed  in  the  gas,  and  the  gas  is  only  able  to  discharge; 
a  charged  body  in  its  neighborhood  which  is  not  illuminated  by  ultra- 
violet rays  when  the  charge  on  the  body  is  positive.  The  r-ray,  on 
the  other  hand,  makes  the  gas  through  which  it  passes  a  conductor 
of  electricity,  independently  of  any  reflection  of  the  rays,  and  the  gas 
thus  made  to  assume  a  conducting  state  is  able  to  discharge  negative!}' 
as  well  as  positively  charged  bodies  when  it  conies  in  contact  with  them. 
Air  ionized  by  the  .r-ray  retains  this  property  if  blown  through  a  bellows 
or  if  heated,  but  it  loses  its  condition  of  ionization  if  it  is  made  to 
bubble  through  a  liquid  or  to  pass  through  a  plug  of  mineral  wool,  or 
if  a  current  of  electricity  is  passed  through  it.  A  gas  ionized  by  the. 
.r-ray  rapidly  Iqses  that  property  by  contact  with  either  non-conductors 
(insulators)  or  conductors. 

Electropositive  metals  lose  negative  charges  to  the  air  when  exposed 
to  ordinal1}"  light  and  do  not  require  the  presence  of  ultraviolet  rays. 

A  gas  which  has  been  ionized  and  rendered  a  conductor  of  elec- 
tricity will  transmit  electricity  at  a  certain  maximum  rate  which  is  not 
exceeded,  no  matter  how  much  the  potential  or  voltage  may  be  in- 
creased. The  most  satisfactory  hypothesis  is  that  each  ion  of  gas  can 
carry  only  a  certain  charge  of  electricity,  and  with  a  definite  number 
of  ions  liberated  in  the  gas  only  a  certain  rate  of  transmission  of  the 
current  is  possible.  An  ion  which  has  performed  us  function  of  carry- 
ing an  electric  charge  apparently  becomes  neutralized  or  bound  again 
and  is  no  longer  capable  of  carrying  electricity.  Hence,  a  layer  of 
ionized  gas  ceases  after  a  time  to  transmit  the  current,  and  a  thin  layer 
ceases  sooner  than  a  thick  layer.  The  maximum  rate  at  which  a  gas 
will  transmit  electricity  is  different  in  various  gases  and  is  called  their 
saturation  current.  That  of  mercury  vapor  is  about  twenty  times  the 
saturation  current  of  air.  It  is  interesting  to  note  t  hat  the  absorption  of 
the  .r-ray  by  different  gases  is  in  proportion  to  their  saturation  currents. 

There  are  two  different  ways  in  which  the  extent  to  which  air  has 
been  ionized  is  used  in  practical  therapeutic  measurements.  One 
method  is  by  observing  the  time  which  an  electroscope  requires  to 
become  discharged  after  having  received  a  standard  charge  and  being 
to  ionized  air.  This  method  has  been  used  in  the  measure- 
t he  amount  of  r-ray  applied  in  therapeutics,  the  electro-cope 
being  placed  at  a  certain  distance  from  the  r-ray  tube  and  exposed 
to  the  direct  rays  from  it  at  the  same  time  that  the  patient  is  being 
treated.  The  rapidity  with  which  the  electroscope  becomes  discharged 
certainly  docs  indicate  t  he  degree  of  ion iz at  ion  of  t  he  surrounding  air, 
but  whether  this  is  due  exclusively  to  the  influence  of  the  r-ray  or  even 
bear.-  such  a  practical  relation  to  it  as  to  form  a  reliable  mean-  of  r-ray 
dosage  is  a  serious  question.  Another  method  of  measuring  the  electric 


(>44  MEDICAL    KI.F.CTRICITY     AND     RtiNTGEN    RAYS 

conductivity  of  ionized  air  is  by  having  a  thin  layer  of  air  between  metal 
plates  which  are  kept  at  a  constant  difference  of  potential  by  a  galvanic 
battery,  and  ionizing  the  air  by  exposure  to  radium  or  other  rays.  The 
ionization  ot  the  air  allows  a  current  to  pass  across  the  air  space  and 
complete  the  circuit.  The  strength  of  this  current  a>  shown  by  a  gal- 
vanometer indicates  the  decree  of  ionization  of  the  air.  This  method  is 
in  constant  use  for  measuring  the  radio-activity  of  uranium,  polonium, 
thorium,  and  radium. 

The  c<n  '  ,  of   mni/ed   air  is  influenced  by  pressure,  but  varies 

either  as  the  pressure  or  as  tlie  square  root  of  the  pressure. 

Her;/  discovered  in  1  ^N?  that  when  ultraviolet  light  falls  u])on  a 
spark  gap  the  discharge  i.-  facilitated.  This  was  the  basis  of  photo- 
electric signalling.  The  artificial  light  richest  in  the  ultraviolet  rav 
u  as  found  io  1  )c  an  arc  light  of  which  one  pole  was  zinc  or  cadmium. 

Cathode.  Lenard.  and  ./'-rays  all  render  ui.y  gas  through  which  they 
]  iass  a  <•!  inductor  of  elect  ricity. 

An  ionized  gas  is  an  electrolyte,  /'.  c,,  a  substance  through  which 
electricity  mav  pass  ami  in  which  the  current  i-  formed  by  the  motion 
of  positively  charged  ions  in  one  direction,  and  negatively  charged  ions 
in  the  other  direction.  In  the  case  of  a  liquid,  which  is  really  the  most 
characteristic  electrolyte,  the  accumulation  of  electropositive  ions  at 
one  pole  and  of  electronegative  ions  at  the  other  pole  is  so  great  that 
there  is  a  demonstrable  change  in  molecular  composition.  'The  libera- 
tion nt  hydrogen  gas  at  one  pole  and  of  oxvgen  ii'as  at  the  other  when 
elect  ricity  i.-  passed  t  hrouu'h  water  is  an  example  of  this:  t  he  water  being 
an  electrolyte,  and  the  chemic  change  bemu  called  electrolysis.  The 
motion  ot  the  ions  toward  one  pole  or  the  other  mav  be  called  phoresis. 
Cat aphorcsis.  or  the  motion  of  electropositive  ions  through  an  elcc- 
trolvte  toward  the  negative  pole,  has  important  uses  in  elect  rothera- 
peutic>. 

I'his   same   process  ot    electrolysis   take-   place   m   solids   and   gases, 

t  hoi '.nl  i    the    molecular   change   or   the  change  demonstrable  bv   chemic 

analysis  i.-  of  t'ar  less  importance  than  is  the  transmission  of  electricity 

l.~  secondary  effects,  radiant  and  oth<  rwise.  produced  by  the  trans- 

missi    :    of  t  he  ci  irrent . 

If  a   platinum  wire  is  heated  red  hot    in  hydrogen  gas.  the  platinum 

I-  r-oi    '  -    po-itive]v.  and    the   hvdrogen   negativelv.  chai'ged.      The  same 

i-  trui    of  iron  or  palladium  wires.      Air  and  all  oilier  gases  differ  from 

hydrogen   in   being  positively  charged,  except    mercun   vapor,  which  is 

tall. 

I '  ;i i  '  '  •••!'•  a rc  i-  passed  t  h rough  o\ v  ^en  v_a>  t  he  oxygen  becomes 
po^jt  •  .  .d  and  \\ill  dischai'ge  a  negatively  charged  body,  or 

\ri  .  •'•  .  ,     charge   to  an   uncharged   bodv.      Tin-   reverse  effect 

i-  prod  ici          •  .      ;in  elect  ric  arc  is  passed  t  h  rough  hydrogen. 

l'i,    !     ,   ninl   \<tjutii'<    Ii>n*<illh<  Sunn    l)iwfni)'tjin(i  I'uint.—,].   Zeleng1 

find.-  that   ioi  -  of  both  -iun-  can  be  detected  near  a  point    from  which  a 

stati'1  current   of  unvarviim  polarity  pa>ses  through   the  air  ton    plate. 

1  •  •  _:•   ol  7  micro-amperes  and  t  he  point  po^it  ive,  the  number 

of  positivi  -  'J.'iH  time-  more  than  the  neu.ati\"e  ion- 

'  i ••-'  -    .'.  ari-e    from    llames    are   electrified    and    are   conductors 

of  i  [)o-itive  and  negative  ions  are  to  !><•  found  in  a  flame; 

1  he.-e  make  a   Halm    all  excellent   conductor  ot   electricity. 
I'hv-.   I'cv.,  xxxiii.   I'M  I .  TO. 


TRANSMISSION    OF    ELECTRICITY    THROUGH     (iASKS  045 


Steatn  arising  from  electrified  water  is  not  electrified.  Vapor 
arising  from  boiling  mercury  is  not  electrified,  no  matter  how  strongly 
the  liquid  mercury  may  he  charged. 

When  a  jet  of  hydrogen  is  burned  in  the  air  the  unburned  hydrogen 
in  the  jet  is  negatively  charged.  Lavoissier  and  Laplace  as  long  ago 
as  1~S-?  noted  the  fact  that  hydrogen  rapidly  liberated  by  the  action 
of  sulphuric  acid  upon  iron  possesses  a  strong  positive  charge. 

According  to  J.  J.  Thompson's  observation,  the  presence  of  an 
electric  charge  upon  a  drop  of  water  tends  to  prevent  the  evaporation 
of  the  water.  C'rookes,  on  the  other  hand,  has  found  that  evaporation 
takes  place  more  rapidly  from  the  surface  of  water  which  is  negatively 
electrified  than  when  the  water  is  not  electrified.  Mascaret's  observa- 
tion is  that  either  positively  or  negatively  charged  water  evaporates 
faster  than  water  which  is  uncharged.  The  possibility  of  error  in  these 
observations  lies  in  the  lack  of  uniform  conditions  as  to  the  humidity 
and  the  temperature  of  the  surrounding  air  and  as  to  mechanic  cur- 
rents in  it  and  in  the  lack  of  uniformity  in  the  conditions  which  would 
ionize  the  air  and  influence  its  electric  conductivity.  If  the  air  in  con- 
tact with  the  surface  of  the  water  were  ionized  it  would  receive  a 
charge  of  electricity  from  the  water  and  be  repelled  from  it,  giving 
place  to  a  fresh  portion  of  air.  which  in  its  turn  would  be  charged  and 
repelled.  Kach  portion  of  air  would,  of  course,  absorb  more  or  less 
water  and  the  result  would  be  a  more  rapid  evaporation  than  the  nor- 
mal, just  as  if  a  current  were  produced  in  the  air  in  any  other  way. 
Then1  are  many  ways  in  which  the  air  might  become  accidentally  ion- 
ized to  a  sufficient  extent  to  affect  the  result  in  an  experiment  of  this 
kind. 

THE    PASSAGE     OF    ELECTRICITY    THROUGH    A    VACUUM 

If  the  air  or  any  other  gas  in  a  glass  tube  be  partially  exhausted  by 
means  of  an  air-pump,  and  there  are  two  wires  leading  into  it,  the 
phenomena  observed  on  connecting  it  with  the  source  of  high  potential 
electricity  may  vary  with  the  degree  of  exhaustion. 

Before  the  tube  has  been  exhausted  a  discharge  will  take  place 
through  it  as  a  xigxag  spark  passing  through  it  from  one  wire  to  the 
ot  her.  and  t  lu1  same  is  true  of  a  tube  in  which  t  he  ii'as  has  been  exhausted, 
but  into  which  air  ha>  entered  in  consequence  of  a  leak  or  a  puncture. 
Such  a  stale  of  things  sometimes  occurs  with  an  .r-ray  tube,  and  it 
indicates  the  presence  of  so  larire  a  \>  ak  :! .::;  no  amount  of  regulation 
of  the  vacuum  will  be  effective  until  the  opening  has  been  found  and 
sealed  up.  The  discharge  through  a  tube  in  'his  condition  does  not 
differ  illy  from  that  which  takes  place  through  the  open  air, 

and  as  in  the  latter  case  the  distance  across  which  the  discharge  will 
pass  is  strictly  limited  to  the  number  of  inches  which  corresponds  to 
the  voltage  or  the  difference  of  potential  o!  the  two  poles.  '1  lie  spark 
length  which  certain  voltages  will  produce  is  variously  estimated  and 
depends  partly  upon  the  .-hape  and  material  of  the  discharging  sur- 
faces. A  spark  1  inch  loirj;  throuuh  the  open  air.  or  in  a  lube-  tilled 
with  air,  requires  ai  the  least  a  potential  of  10.000  volts. 


r>4»i 


MEDICAL    ELECTRICITY    AM)    RONTGEN    KAYS 


A  vacuum  tube  exhausted  to  the  C I  eissler  degree  of  ,  ,l\,(.  atmosphere 
does  not  become  luminous  on  the  passage  of  a  continuous  current, 
no  matter  ef  what  tension.  The  moment  the  current  is  made  inter- 
mittent or  alternating  the  tube  lights  up.  The  illumination  also  takes 
place  if  tin1  tube  contains  mercury  vapor  or  certain  other  gases. 

A  tube  exhausted  to  this  slight  degree  becomes  filled  with  reddish, 
bluish,  or  violet  liirht  when  the  high-tension  interrupted  current  is 
turned  on,  there  bein^r  no  visible  or  audible  spark  passing  through  it, 
and  this  li^lit  is  more  or  less  st  rat  if  led,  seeming  to  pass  1  h  rough  the  tube 
in  waves.  <  leissler  tubes  (Fiir.  394')  of  different  shapes  were  favorite 
laboratory  toys  and.  were  the  forerunners  of  the  Crookes  tube  and  of  a 
modern  focus  .r-ray  tube.  A  tube  which  becomes  filled  with  bluish  or 
re  1 1  4;sh  liii'hr  allows  the  cathode  si  ream  to  pass  directly  from  the  cathode 
to  the  anode  and  does  not  present  as  great  resistance  to  the  passage  of 
electricity  as  one  with  a  higher  degree  of  vacuum,  i,  c.,  from  which  the 
iras  has  been  more  completely  removed,  and  it  does  not  generate  a 
useful  quantity  of  .r-rays.  The  study  of  all  the  phenomena  caused  by 
the  cathode  rays  has  been  more  successfully  performed  upon  the  tubes 
with  a  higher  vacuum. 

A  Crookes'  tube  is  a  glass  tube  containing  an  almost  complete  va- 
cuum of  about  f7]i,yUOQ  atmosphere. 

Crookes'  theory  in  regard  to  a  tube  exhausted  to  this  degree  was 
that  the  molecules  were  so  few  and  far  between  that  they  could  move 
from  one  wall  of  the  tube  to  the  other  without  encountering  other 

molecules.  This  is  the  ultragaseous  state  of 
matter.  It  was  formerly  believed  that  the 
cathode  ray  consisted  of  molecules  of  the 
residual  gas,  but  it  is  now  thought  to  consist 
of  particles  of  matter,  perhaps  only  one- 
thousandth  the  sixe  of  an  atom  torn  from 
the  atoms  and  thrown  from  the  surface  of  the 
cathode. 

Such  a  tube  offers   great    resistance  to   the 
passage  of  electricity,  and  even   with  a  source 
of  very  high  potential  will  transmit  a  current 
of  roily  a  few  milliamperes.      If  its  two  termi- 
nals are  simple  wires  leading  into  the  tube  not 
much  change  may  be  noted,  on   turning  on  the 
current.     There   may   be   a    little  fluorescence1 
of  the  glass  around  the  negative  pole  and  this 
mav  be  of   the    greemsh-vellow  tint    which    is 
excited  in    ordinal'}'  lilass   bvthe  cathode  ray. 
This  is  apt    to   be   greatest   around  the  cathode 
or  negative  wire.      The   rest   01    the   tube   may 
present    little   or  no   color,  there  will  be  some 
heating  of  the   glass   near   the    two  wires,  and 
•  t      near     the     cathode, 
es'     lube    of    this    con- 
inena  t  akmg  place  m  it 
i  li.-covery  ot  the   ,r-ray. 
|  ihi  'in  imena    produced 
.-•  in))'1  a  re  p-sult  s  of  t  he 
material    particles    much 
at    a    nuhl    amde    to    its 


The    Cathode    Rav.- 


this     is     often     greate 
While    a   simple   Crool 

I'V    UnUSUal,    1  lie    plielK  i 

their  Mud;/  led  to  the 
I-  most  important 
icii  v  t  hroi  i-h  a  (  rookes 
ij-obably  a  Stream  < 
ven  from  the  cat  i  10 


TRANSMISSION    OF    ELECTRICITY    THROUGH    GASES  647 

surface  and  carrying  a  negative  charge  of  electricity.  The  other  hypoth- 
esis that  the  cathode  ray  consists  of  vibrations  in  the  hnniniferous 
ether  does  not  explain  many  of  the  phenomena  as  well  as  this  corpus- 
cular theory. 

According  to  the  theory  adopted  in  the  present  work  the  cathode 
stream  of  material  particles  proceeds  from  every  part  of  the  cathode 
at  a  right  angle  to  its  surface,  and  without  regard  to  the  position  of 
the  anode.  The  cathode  stream  is  invisible,  but  its  presence  can  be 
readily  demonstrated  to  the  eye  by  the  fluorescence  which  it  will  excite 
in  various  gaseous,  liquid,  or  solid  substances  placed  inside  the  tube 
and  by  the  mechanic  motion  which  it  will  produce.  Sometimes  in  an 
.r-ray  tube  if  t  lie  vacuum  becomes  very  low  the  visible  fluorescence 
produced  by  the  passage;  of  the  cathode  ray  through  the  gas  can  be  seen 
as  a  bluish  streak  passing  from  the  cathode  to  the  anticathode.  If 
the  cathode  consists  of  a  straight  rod  or  wire  pointing  toward  the  anode, 
the  cathode  stream  will  proceed  chiefly  from  the  lateral  surface  of  the 
rod.  since  that  is  of  greater  extent  than  its  end.  It  will  cause  motion 
in  a  little  wheel  made  up  of  several  vanes  or  fan-like  disks  revolving  on 
an  axle  in  the  same  way  that  a  current  of  air  or  water  produces  motion 
in  a  wind-mill  or  a  water-mill.  The  best  arrangement  is  to  have  one 
surface  of  each  vane  covered  with  polished  metal  foil  and  the  other 
surface  roughened,  or  a  shield  may  be  placed  so  that  the  cathode  stream 
can  strike  only  the  vanes  on  one  side  of  the  wheel.  The  unopposed 
impact  causes  the  wheel  to  rotate.  The  same  motor  effect  can  be  pro- 
duced in  a  tube  in  which  the  cathode  is  formed  by  a  disk  or  a  concave 
circle  of  metal,  as  is  the  case  in  an  .r-ray  tube.  This  directs  the  cathode 
stream  toward  the  particular  spot  desired  to  influence. 

The  luminous  effects  of  the  cathode  ray  are  seen  in  the  fluorescence 
it  excites  in  the  glass  wall  of  the  tube,  and  this  is  of  different  colors  with 
glass  of  different  composition;  for  instance,  glass  containing  a  large 
percentage  of  lead  changes  to  a  beautiful  blue,  while  the  ordinary  glass 
assumes  a  yellowish-green  tint.  If  a  solid  object  such  as  a  glass  or 
metal  disk  or  cross  is  placed  in  the  path  of  the  cathode  stream,  a  dis- 
tinct shadow  is  cast  upon  the  wall  of  the  tube.  Beautiful  effects  are 
seen  when  various  substances  are  introduced  into  such  a  tube.  Under 
the  influence  of  the  cathode  ray  the  following  substances  show  phos- 
phorescence with  the  specified  colors: 


CuSO, 

CuSO     -  MnSO 


St-SO,    •-  MnS<  ),  ......... 

M:iS()  ..................... 

HiiSO,    f   MnSO,   . 

M-So't  ................... 

M--M  \    -   1  PIT  cent.  MnS<  >, 
Y.n>(  ),  .................... 

\a,S(  )(    -•  ()..")  per  cent.  MnS(  ) 
(MSO,  .......... 

CaFl  .......... 

Cnl-T    i    Mull, 


upon  what  Thomson   ca 


MEDICAL    ELECTRICITY    AND    RONTC.KN    RAYS 


df  electricity  is  due1  to  the  published  works  of  Professor  J.  J.  Thom- 
son of  Cambridge  University.  England  (The  Discharge  of  Electricity 

t  hrouu'h  (  lases)  .  These  "solid  solutions"  arc  formed  \vhcn  two  salts,  one 
greatly  in  excess  of  the  other,  are  precipitated  simultaneously  from  a 
liquid  in  which  both  are  held  in  solution,  the  familiar  barium  platino- 
cyamd  of  the  lluoroscopic  screen  for  x-ray  work  is  an  example  of  a 
"  solid  sohll  l<  HI." 

The  cathode  stream  travels  at  the  rate  of  about  'JO.  000  miles  a 
second  and  in  a  straight  line,  from  which,  however,  it  may  be  deflected 
in  a  variety  of  ways.  It  is  arrested  by  the  glass  wall  of  the  tube,  and 
a  thin  sheet  of  glass  placed  within  the  tube  and  across  the  path  of  the 
cathode  stream  casts  a  very  dark  shadow  contracting  with  the  fluores- 
cence  of  the  wall  of  the  tube.  Gold-leaf  is  less  opaijiic.  A  sheet  of 
aluminum  O.OO'Jti")  millimeters  thick  forming  a  window  in  the  wall  of 
the  tube  will  allow  the  cathode  ray  to  pas-;  through  it  in  sufficient 
amount  to  produce  visible  light  and  to  cause  phosphorescence  in  bodies 
outside  of  the  tube.  Experiments,  with  a  great  variety  of  substances 
have  shown  that  the  most  phosphorescent  substance  is  a  piece  ot  tissue 
paper  soaked  in  a  solution  of  pentadekylparatoleketon, 

The  cathode  rays  suffer  diffuse  reflection  when  they  fall  upon  a 
surface,  whether  it  be  of  an  insulator  or  of  a  conductor.  Cathode  rays 
start  in  all  directions  from  such  a  surface,  especially  if  the  rays  have 
struck  it  obliquely.  And  the  substance  struck  generally  becomes  itself 
a  cathode  and  emits  cathode  rays,  principally  normal  or  perpendicular 
to  it.-  surface.  These  reflected  or  secondary  cathode  rays  occur  inde- 
pendently ,,]'  ilu.  existence  of  x-rays,  the  latter  are  ethereal  vibrations, 

while  the  cathode  rays  con- 
sist of  particles  of  matter. 
The  cathode  stream  under- 
goes no  regular  refract  ion.  but 
it  may  be  deflected  from  its 
si  raight  pat  h  by  a  magnet  . 

1)>  /!«•/,'(,//  of  /he  (  'aUiotlc 
S(t'<tit/i  I///  it  Miit/tnl.  —  The 
cathode  stream  is  deflected 
toward  a  magnet  (Fig.  o9~)  > 
atn  1  1  his  is  t  he  case  wit  h  t  he 
]  »  tsit  ive  (  ir  neirat  ive  pole  or 
I  n  it  li  poles,  as  in  t  he  case  of 
a  hi  >rsesh<  >e  magnet  . 

-covered  a  magnetic  spectrum  in  the  cathode  stream, 
mi;  more  deflected  than  other.-,  and  the  result  being 
ho-phorescence  instead  ot  a  single  spot. 
;  that  tin-  was  due  to  inequalities  in  voltage  in  suc- 
t'rom  an  induct  ion-coil,  a  n<  1  that  it  does  not  occur  with 
tatic  machine  or  troni  a  large  batterv  of 


th    1  \\  o    cathode-    so 
heti    they    leave    the 

-1  re  a  Ills    will     I  •'•    found     to    repel    each 
iveri:<nt     curve.-.       1  hi-    seems    almost 


TRANSMISSION    OF    ELECTRICITY    THROUGH    OASES  049 

conclusive  evidence  that  the  cathode  stream  consists  of  particles  of 
matter  charged  with  negative  electricity.  The  particles  in  both  streams 
are  similarly  charged  and  consequently  repel  each  other.  This  propertv 
is  taken  into  account  in  the  construction  of  an  .r-rav  tube,  the  platinum 
disk  or  anticathode  upon  which  the  cathode  stream  is  to  be  focused  is 
no!  placed  at  the  center  of  curvature  of  the  cathode  mirror,  but  at  a 
point  considerably  further  away,  the  repulsion  between  the  particles 
of  the  cathode  stream  deflects  them  so  that  thev  meet  at  a  point  beyond 
what  would  be  the  focus  if  each  particle  proceeded  in  a  straight  line 
at  a  right  angle  to  the  part  of  the  surface  of  the  cathode  from  which 
it  started. 

Lenard  Rays. — The  cathode  rays  which  have  passed  through  an 
aluminum  window  and  so  have  escaped  from  the  vacuum  tube  present 
very  similar  characteristics  to  the  cathode  rays  inside  the  tube,  but  are 
given  the  distinguishing  name  of  Lenard  rays,  after  their  discoverer. 
They  spread  out  very  diffusely  and  cast  .-hadows  of  solid  object.-  which 
are  larger  than  the  geometric  ones  or  larger  than  would  resuit  from 
ray-  traveling  in  a  perfectly  straight  line  from  a  single  point.  They 
cause  photographic  effects,  but  since  the  ./'-rav  is  also  present  under 
these  conditions  it  is  hard  to  say  just  what  part  the  Lenard  rays  play 
in  this.  These  rays  are  arrested  by  quart/  crystal,  but  pass  through 
alum.  They  discharge  bodies  charged  with  either  positive  or  negative 
elect  ri city  as  do  t  he  .r-rays.  These  rays  and  all  t  h  •  propert  ies  attributed 
!<i  them  were  discovered  before  the  .r-ray,  and  some  of  these  properties 
may  be  due  to  the  latter;  still,  the  discovery  of  the  x-ray  has  not  thrown 
any  doubt  upon  the  existence  of  Lenard  rays.  There  is.  however, 
some  doubt  as  to  whether  the  Lenard  rays  cons'sl  of  material  particles 
or  of  vibrations  in  the  luminiferous  ether.  Their  passage  through  solid 
bodies  gives  some  ground  for  the  latter  theory,  but  J.  -I.  Thomson 
believes  that  they  are  corpuscular  in  nature.  The  cathode  rays  lose 
about  10  per  cent,  in  velocity  in  passing  through  an  aluminum  window 
and  emerging  from  a  ( 'rookes  tube  as  Lenard  rays. 

Channel  Rays  i  Kanalstrahlem. — (iold.-tein1  discovered  the  pre— 
enee  of  the<e  rays  in  a  vacuum  tube.  They  are  produced  with  a  per- 
forated cathode,  are  found  only  neat  the  cathode  and  behind  it,  and  are 
not  deflected  bv  a  magnet,  and  their  only  known  property  is  that  of 
beiim-  accompanied  bv  luminosity.  Possibly  they  are  jets  of  phosphor- 
escent gas  emitted  from  the  perforations  m  the  cathode  by  a  sort  ni 
explosion.  They  are  made  tip  of  positively  charged  particles  of  matter. 

Lodge's  Theory  of  the  Transmission  of  Electricity  Through  Gases.-- 
Lodge  considers  that  the  principal  part  is  played  by  positive  ions  pa-s- 
ing from  the  anode  to  the  cathode  along  the  path  of  least  resistance. 
The  role  of  the  negative  electrons  projected  from  the  cathode  normally 
to  it-  surface  he  regard-  as  subsidiary,  not  contributing  directly  to  the 
tran.-portation  of  electricity.  The  electrons,  however,  are  emitted  with 
ureat  force  and  velocity  and.  according  to  l.odue  -  theory,  they  may  col- 
lide with  the  positive  ions  and  so  interfere  with  their  access  to  the  cathode, 
and  under  certain  circumstances  prevent  the  flow  of  the  current,  lor 
instance,  in  a  valve  tube  the  -i/e  and  position  of  the  electrodes  is  such 
that  with  an  alternating  potential  only  current-  in  one  in-tance  can 
casilv  net  through.  The  current  can  easilv  pass  in  such  a  direction  that 


050 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


the  lartiv  electrode,  with  free  access  to  its  surface,  is  the  cathode,  and 
is  uTeatly  impeded  when  the  -mall  electrode  in  a  narrow  part  of  the  tube 
is  the  cathode. 

Magnetic  Rays  or  Magnetocathodic  Rays.^  Righi1  distinguishes 
these  from  ordinary  cathode  rays  by  the  fact  that  in  the  former  some 
of  the  electrons  unite  with  poMtive  ions,  forming  systems  analogous  to 
a  planet  and  its  -atellite  the  rotation  of  which  is  controlled  by  the  magne- 
ti-  current.  The-e  rays  result  from  the  action  of  a  magnetic  iield 


--—  . 

A 

VVVV^VVp                                                                            _  — 

^>  + 

y 

c           ^\ 

.< 

upon  a  cathode  stream.     They  are  repelled  to  a  portion  of  the  tube  where 
the   magnetic   held   is   weakest;    there  they  become  dissociated  and  an 

accumulation  of  positive  ions  is  demonstrable. 

The  .r-Ray. — When  the  cathode  ray  as  a  stream  of  material  particles 

traveling  at   the  rate  of  20.000  miles  a  second  strikes  any  solid  object. 

such  as  the  glass  wall  of  the  original  ( Yookes  tube  or  the  platinum  disk 

in   the  modern /on/s  .r-ray  tube,   the  impact   gives  rise  to  the  ethereal 

vibrations  known  as  the  r-ray.      Were  particles  as  large  as  pebbles  to 

bombard  any  hard  surface  at   a  tremendous  velocity   the  effect   would 

b<-  vibrations  in  the  air  which  would  be  perceptible  as  a  deafening  noise. 

In  a  vacuum  tube  the  moving  bodies  are  only  one-thousandth  the  size 

oi  an  atom  and  the  <peed  at  which  ihev  strike  is  inconceivably  great. 

The  result  is  eijiiaily  beyond  the  range  of  the  human  senses;  vibrations 

in   the  luminiferous  ether  five  or  ten  times  as  rapid  as  the  most   rapid 

vibrations  of  vi-ible  li^lit.  and  million-  of  times  as  rapid  as  ihe  highest 

'li'oie   sound-waves.      A    special    part   of  the   present    work   is 

I   i'-  t'li.    consideration  of  the  .r-ray.      It    is  mentioned  here  only 

if  '  :.'•  :  henomena  produced  by  i  lie  passage  of  electricity  t  h rough 

i  mi  '  ibe  and  for  the  purpose  of  detailing  the  differences  between 

t  he  cat  hode  ray. 

Iliiinai  tin   Cdlliafli  ////'I  .r-I\'<i //.-•.—  The  cathode  rays  differ 

ts     ilial     they    carry    a    charge   of   negative1   electricity 

a]    ;  •'..••    ih'-;    an    deflected  from  their  straight   pal  h  by  the  influence  of 

or  of  a  magnet.     Cathode  rays  consist   of  particles  of 

./•-ray   i-  a   form  of  motion   like  liidit   and  heat.     The 

-    e--(.]]t  jally    a    phenomenon    occurring    m-ide   a    Crookes 

little   penetrating   power,    while   the  .r-ray   is  chieflv 

-  outside  of  the  tube  and  ha-  great  penetrative  power. 

HI  tin  tH  ('iithni/i    titnl  .r-li'n  i/.--.      Tliey   boi  h   iolii/.e  the  air, 


TRANSMISSION    OF    ELECTRICITY    THROUGH    CASKS 


051 


rendering  it  a  conductor  of  electricity,  net  on  photographic  plntos, 
produce  fluorescence,  and  arc1  incapable  of  regular  reflection,  refraction, 
or  polarization.  They  both  give1  rise-  to  cathode  rays  and  ./'-rays  when 
they  strike1  a  solid  substance. 

Passage  of  Electricity  Through  a  Practically  Perfect  Vac-innn. —  Kxperi- 
nients  by  Coolidge  with  .r-ray  tubes,  exhaustc-d  far  beyond  the  ordinary 


loot) DOC)  Atmosphere,  show  that  no  current  passe- 
voltage  while  the1  electrodes  are1  cold,  but  that  it  will  do  so  if  the  cathode1 
e-onsists  of  tungsten  wire1  and  is  heated  by  a  e'urrcnt  passing  through  it. 
In  that  case  even  as  low  a  voltage1  as  220  may  send  a  current  through  this 
vacuum.  A  Rontgen.  ray  tube1  constructed  upon  this  prine-iple-  is  de- 
scribed  on  page  774. 

Special  Forms  of  Geissler  Tubes. — Vacuum  tube-s  which  are  not 
exhausted  to  the1  .r-ray  degree1  have  already  been  spoken  e>f.  In  Un- 
original type  there-  were  two  leading-in  wires  and  the-  whole  bulb  became- 

filled  with  colored  liirht  which  was  more  or  less 
stratified.  This  light  could  be1  concentrated  at 
one  spot  if  the  finger  was  applied  to  the-  side 


Fig.  397. — A'-rav  tube. 


Fig.  3!)S.-    t.ieissler  tube,   showing   cathode 
stream. 


of  the-  bulb  (Fig.  398)  and  the  finger  then  received  a  slight  discharge 
of  electricity  from  the  surface1  of  the  glass,  from  this  early  type  have 
been  evolved  the-  vacuum  electrodes  which  form  such  an  important  part 
of  high-frequency  apparatus.  A  glass  bulb  with  a  suitable  stem  (Fig. 


.  309. — Cieissler  tube  for  use  as  a  vacuum  electrode.      Insulated  handle. 


;W.>';  and  e'xhausted  to  the  proper  decree  may  be  excited  by  connection 
with  one  pole  of  a  static  machine,  .r-ray  coil,  or  high-frequency  apparatus. 
This  does  not  re-quire-  the1  presence  of  any  wire1  at  all  leading  into  the  tube1, 
and  if  there  is  none,  the  elect  rifica  t  ion  of  the1  enclosed  gas  must  take 
place1  by  a  sort  of  condeMise-r  action.  The  metal  handle  is  charged  from 
the1  static  machine1,  we  will  say.  and  induevs  in  the1  gaseous  c-onte-n;,-  a 


ti.Y2  MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

charge  through  the  u1a<s  wall  of  the  tube.  The  gas  becomes  luminous 
with  a  violet  light  and  with  a  certain  degree  of  vacuum  such  a  tube  will 
be  found  to  give  out  liuht  which  contains  an  appreciable  amount  of 
the  ultraviolet  rays,  the  invi.-ible  actinic  rays  beyond  the  violet  end  of 
'he  solar  spectrum.  The  presence  of  the  ultraviolet  ray  is  most  readily 
demonstrated  bv  the  fluorescence  it  excites  in  a  piece  of  \\  illemite  held 
near  the  tube.  The  activity  of  the  tube  is  greatly  increased  by  making 
some  additional  connection,  for  instance,  by  touching  the  other  end 
with  the  hand.  When  there  is  a  leading-in  wire  passing  through  the 
glass  \vall  of  the  tube  the  visible  ef'feci  is  the  same,  but  it  doe-  not  take 
>o  -troiiii  a  charge  of  electricity  to  excite  it.  The  color  of  such  a  nibe 
varies  with  the  degree  of  exhaustion,  the  kind  of  gas  contained  in  it. 
and  the  composition  of  the  glass.  Such  a  tube  may  be  made  long  and 
;  into  a  flat  -piral  (Fig.  400)  with  leading-in  wires  connected  with 
the  two  poles  of  an  .r-ray  coil,  and  gives  a  beautiful  violet  and  ul'ra- 
violet  radiance  with  very  little  discharge  of  electricity  to  the  patient. 


Vacuum  Tubes  for  Electric  Illumination. — The  first  electric  light 
on   record  was  reported  bv  Hawksbee  two  hundred  years  ago.      It    was 
•  .uiii  tube  which  when  connected  with  one  pole  of  a  frictional  static 
machine  {rave  sufficient  light  to  read  large  print  by. 

lh''  pract  icable  vacuum  tube  lights  at  the  present  da\'  all  depend 
lorescence  exciter]  in  the  residual  gas  by  the  passage  of  an 
eject  ri'1  current  through  it.  In  the  ('ooper  llewitt  lamp  the  current 
i-  of  the  direct  110  volts.  In  the  Moore  lamp  an  alternating  current  of 
~>00i)  volts  i>  ii-i.-cl.  In  the  Tesla  h'Lili!  the  yolta.ire  has  been  raised  by  a 
: . .  •  '  i  ransfi  irmer. 

The  '  <>":     i-   //•-//•///  Itit/ifi     \"]'^.  401  •  consists  of  a   vacuum  tube  about 

1  .  ler  and   from   '_'  to    I   feet    long.      It    contains  a  certain 

•<:    metallic    mercury   and.    of    course,    i-    filled    with    mercury 

Her  i-  M  very  pool'  con d  net  or  of  elect  ric it  v  when  cold,  and 

•    ii    i-  necessary  either  to  tip  (he  lube  and  make  a 

ction    ot    liquid    mercury   Irom   pole   to  pole,   or  else  to 

current    of  at    least    IMDii   volts   through   it    fi'om   an 

!  '       I'll  he;-      ca-e     I  he      I  10-Voll      ci  in'  inuoits     CU  ITi  'li  I      l.- 

.     •  •          .  ore>c(-lice. 

'•  >i  ii  i  and    ;  i  ii     la  t'L;er  -;  /« •   7'H  i  <  ;,  IM  i  h  •-[  <  >\\  er. 

i .  but  not  nen        •      •     ,   '    •     • ;  •    power  is  con- 

lical       '      •       II1    dec!  I'jc         .      •  '    .  ;      •     :  ,       a  n  .peri   - 

I    -    elli'Mi  nc;\     i-    ci  tri'i  '-poi  hi'jh,    in    fact . 

'     .  '     require.-    oiil\      i     \\  at  1     pel     cahdle-pi  i\\  (•]',    \\  hlle 

:  '  '.  a  n ;  p  e  re  a  n  d    1  1 0  \-  o  1 1  s , 

•  i     \\  a't-  per  candh  -power.      Tin    cat  hode  terminal 

'     I  In      :!       •    '  end    o|'    t  he    I  ilbe.       The    ]  lo.-il  ive 
Tin      I     iopcr    !  Ie\     I  :      (.;,-    about     t  he 

Tin    lidii 


TRANSMISSION    OF    ELECTRICITY    THKOl.'GH    CASKS 

Drills  the  spectrum  of  incandescent  mercury  vapor,  it  is  rich  in  violet 
rays,  and  almost  entirely  lacking  in  red  rays.  It  is  not  especially  rich 
in  ultraviolet  rays,  as  tested  l>v  \\illeniite.  A  verv  interesting  observa- 
tion may  he  made  with  the  spectroscope  in  connection  with  this  lamp 
described  m  the  next  paragraph. 

Nature  of  Fluorescence.  Fluorescent  substances  have  1he  prop- 
erty of  intense  absorption  of  light  at  their  surfaces  and  of  slowing  tin- 
rate  of  vibration  of  light  falling  upon  them.  In  the  case  of  the  mercury 
vapoi1  light  a  piece  of  cloth  saturated  with  a  solution  of  a  fluorescent 
substance  like  rhodamin,  and  dried,  mav  be  wrapped  around  i  he  luminous 
Tube.  Red  lines  and  others  not  in  the  mercury  spectrum  \vill  immediately 
be  seen  with  the  spectroscope.  It  is  in  t  he  same  way  that  \\  ill  emit  e  slows 
up  the  vibrations  of  invisible  ultraviolet  light  and  changes  it  to  a  bril- 
liant green.  Something  of  an  analogous  nature  must  take  place  in  con- 
nection with  the  ionization  of  the  air  by  the  ultraviolet  ray.  It  will  be 
remembered  thai  the  ultraviolet  rav  ionixes  a  u'as  and  renders  it  a  con- 


ductor  of  electricity  and  capable  of  discharging  a  cliarged  body  onh 
when  the  light  is  reflected  from  a  fluorescent  substance  or  from  a  metal 
immcrsei  lint  he  gas. 

The  Cooper  Hewitt  light,  of  course,  does  not  give  the  natural  color 
to  objects  illuminated  by  it.  lied  objects  appear  blue  or  purple  and 
every  little  capillary  in  the  skin  and  the  entire  mucous  surface  of  the 
lips  appears  bluish.  The  visible  effect  is  as  it  the  person  were  dead  and 
decomposition  had  begun.  While  it  is  not  suitable  for  general  illu- 
mination, excellent  photographs  may  be  made  by  it.  either  originals 
or  reproductions  from  others.  It  is  made  up  almost  exclusively  of  the 
most  aclinic  ravs  of  visible  light  and  on  ihis  account  has  seemed  of  value 
to  the  present  author  in  the  treatment  of  tuberculosis  by  light  baths. 

The  uviol  lamp  is  made  of  glass  which  transmits  a  greater  percent- 
age of  ultraviolet  rays.  The  eyes,  however,  should  be  protected  from 
a  light  so  rich  in  ultraviolet  rays. 

Moore's  Vacuum-tube  Light.-  Tube.-  of  an}-  length  ma}-  be  used 
and  passed  from  room  to  room,  distributing  the  light  just  like  the  steam- 


054  MEDICAL    ELECTRICITY    AND    KONTGEN    RAYS 

or  iias-pipes.  They  are  connected  at  a  central  box  in  the  cellar  or  else- 
where with  the  alternating  current  of  110  volts,  or  with  the  110-volt 
direct  current  modified  by  the  use  of  a  vacuum-tube  rotator,  producing 
extra  currents  by  its  sudden  breaks  in  passing  through  an  electromag- 
netic coil.  Kit  her  of  these  currents  is  passed  through  a  step-up  trans- 
former, raising  it  to  5000  volts.  Any  kind  of  vapor  may  be  used  in 
the  tubes  and  light  of  any  desired  color  and  spectrum  may  be  produced. 
Daylight  may  be  imitated  very  closely.  The  light  is  accompanied  by 
very  lit  t  le  heat . 

The  Nikola  Tesla  Vacuum-tube  Light. — This  is  produced  in  a 
vacuum  tube  of  any  length  by  charging  and  discharging  a  condenser 
and  passim:  the  discharge  through  the  primary  of  an  induction-coil. 
The  secondary  current  thus  obtained  is  of  very  high  voltage  and  fre- 
quency and  can  be  used  with  tubes  with  or  without  leading-in  wires. 

Disruptive  Nature  of  Vacuum-tube  Transmission. — A  discharge 
of  electricity  through  a  gas  which  has  been  ionized  can.  it  is  true,  take 
place  by  simple  conduction,  as  in  the  apparatus  employed  for  testing 
the  radio-activity  of  radium  salts,  or  in  testing  the  quantity  of  the  .r-ray 
bv  the  rapidity  with  which  a  charged  electroscope  becomes  discharged, 
but  such  a  transmission  of  the  current  is  as  free  from  any  special  phenom- 
ena as  if  the  charge  were  conducted  by  an  equal  length  of  copper  wire. 
The  discharges  through  1  he  vacuum-tubes  which  have  just  been  described 
are  essentially  of  the  nature  of  sparks  or  disruptive  discharges  breaking 
through  the  gas.  not  carried  bv  it.  Still  the  same  ionixed  gas  will  also 
transmit  electricity  in  the  silent  and  invisible  manner  characteristic  of 
true  conduction.  A  Cooper  Hewitt  lamp,  for  experiment,  may  have  a 
couple  of  leading-in  wires  at  opposite  sides  near  the  middle  of  the  length 
of  the  tube,  and  these  two  opposite  wires  may  be  connected  with  wires 
leading  from  a  galvanic  batterv  of  one  or  two  cells.  A  galvanometer 
placed  in  the  circuit  will  show  that  no  current  passes  through  the  battery 
circuit  until  the  Cooper  Hewitt  light  is  turned  on.  and  the  rarefied  gas 
In-'  ween  i  he  t  wo  wires  coming  from  the  bat  t  cry  and  leading  into  the  tube 
is  ionixed  and  becomes  a  conductor  of  electricity. 

A  cln  i/iiciill//  (ictirc  fur-in  of  in'tro'icii  is  produced  when  pure  nitrogen 
ga-  i-  u>ed  in  a  (  ieissler  tube  and  an  elect  ric  discharge  takes  place  through 
it. 

The  explo.-ive  distance  in  vacuum  tubes  is  increased  in  a  magnetic 
held  parallel  with  the  space,  and  there  is  a  best  .Mrength  for  the  field.1 

A  tube  may  light  up  in  a  field  of  1  KM)  gauss  and  become  dark  in  a 
field  of  ill  Hid  gau>s  (electromagnet  with  a  current  of  1(1  amperes). 

Cc.uv.r.  H.  <lc  la  Sor.  do  Biol.,  i:,(l,  1!)1(),  l.V.'J,  an<l   lf>l.  l!H(),  i:;20. 


PHOTOTHERAPY 

LIGHT  as  a  therapeutic  agent  has  become  very  prominent  during  the 
past  few  years,  and  its  action  is  due  to  the  luminous  rays,  the  cheinic 
rays,  and  the  heat  rays.  It  was  thought  at  one  time  that  the  heat  rays 
were  confined  to  the  infra-red  and  red  of  the  spectrum,  but  it  is  now 
known  that  there  are  heat  rays  through  the  entire  spectrum.  The 
cheinic  rays  were  at  one  time  thought  to  be  confined  entirely  to  the 
blue  and  violet-blue  portion  of  the  spectrum,  but  it  is  now  known  that 
they  also  are  found  throughout  the  entire  visible  spectrum.  The  heat 
rays  found  in  the  infra-red  part  of  the  spectrum  are  invisible. 

Temperature  oj  Incandescence. 

DKCKKKS 
FAHRENHEIT. 

1000 Kod  rays. 

1200 Orange  rays. 

1300 Yellow  rays. 

1.100 JMuc  rays? 

1700 Indiiro  rays. 

2000 Violet  rays. 

2i:!0 All  colors  =  white  lipht 

The  intensity  of  the  light  increases  faster  than  the  temperature.  IMat- 
inum  wire  at  2000°  F.  gives  out  fortv  times  as  much  liu'ht  as  at  11)00°  F. 


The  temperature  of  the  voltaic  arc  is  about  3000°  C.  for  the  positive 
carbon  and  L'oOO0  ('.  for  the  negative. 

In  addition  to  the  ordinary  cheinic  rays  which  accompany  the  visible 
rays  of  light,  there  are  what  are  known  as  the  ultraviolet  rays:  these 
are  beyond  the  violet  and  are  also  invisible.  An  illustration  of  what 
are  known  as  infra-red  rays  is  The  heat  effect  noticed  when  the  hand  is 
brought  near  a  stove  in  which  then1  is  a  fire.  These  rays  are  more  pene- 
trating than  I  he  visible  rays  of  the  spectrum.  The  strength  of  light  varies 
inversely  as  the  square  of  the  distance;  this  is  an  important  law  to 
remember:  t  lius.  if  at  a  distance  of '.}()  inches  t  he  candle-power  is  ")()(),  then 
at  a  distance  of  (10  inches  the  candle-power  will  be  only  one-quarter, 
or  r_'.~>  candle-power.  The  usual  distance  from  the  filament  at  which 
the  candle-power  of  an  incandescent  lamp  is  measured  is  .'->0  inches,  so 
that  it"  the  patient  is  at  this  distance  from  the  filament,  the  full  rated 
candle-power  of  the  lamp  is  being  used.  Another  point  to  remember 
is  that  liirht  is  most  effective  when  it  strikes  the  surface  at  right  angles. 
In  order  to  compare  different  lamps  an  actinometer  such  as  is  used  by 
photographers  can  be  placed  on  the  patient.  In  order  to  use  this  cor- 
rectly, all  other  light  must  be  excluded. 

655 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAY8 

TIII:  ro.Mi'LKTi:  SIM-XTRTM  OF  LICHT 


Hrat    J 
liavs.  1 


'I'ri-ultra-rcd. 
Wave    I.ciitilli:   Very  lonj. 


Tri-ultru-rcd. 

\\  ;i\'c  Lcntit  h  :    is  micniM>. 


(ELECTRICITY    ?) 


ritra-rcd. 

\\  avc   Lentil  h  :   s  micron.-. 


Rod. 

\\avr    Lcnglli:   .71  micron 


\\  avc   Length  :   .(>(>  micron. 

Yellow. 

Wave   Length :   .()!_'  micron. 

(  irceii. 
\\'ave    I,en<it  li :    .'','.',  micron. 

Blue. 


in  ten  tlinu.-atnl  millioni  li-  jiart  ol  a 

I .     -  '  ' 

r  ailiuin  i  .  . 


Finson 
Rays. 


PIK/roTHEKAPY 


057 


Practical  Units  of  Light.  1  Candle-power  (British  and  I'.  S.  stand- 
ards) is  the  light  of  a  spermaceti  candle  £  inch  in  diameter,  burning  120 
Drains  an  hour;  1  meter  candle-power  is  the  illumination  produced  by  1 
candle-power  at  a  distance  of  1  meter.  This  is  useful  as  a  unit,  but  the 
light  varies  so  much  under  different  conditions  (hat  more  exact  stand- 
ards have  been  devised  for  making  the  actual  measurements. 

1  Hcc  Carer/  (French  standard,  equal  1o  9.5  British  standard  candle- 
power)  is  the  light  of  a  Cared  lamp  burning  42  "Tains  of  pure  Col/a 
oil  per  hour  with  a  flame  40  mm.  high,  under  conditions  fixed  by  Dumas 
and  Ke*gnault. 

1.  Hefner  is  the  light  from  a  standard  amyl-acetate  lain]),  burning 
under  conditions  prescribed  by  the  late  von  I  leaner  Alteneck,  and  equals 
0.88  British  standard  candle-power. 

1.  Lux  is  the  illumination  produced  by  1  Hefner  at  a  distance  of  1 
meter  and  equals  0.88  meter  candle-power. 

1   LIUHCH  is  the  unit  of  flux  of  light  in  a  beam  subtending  unit  of 


Fi<:.  40L*.  — F.  Tildon  Brown's  cystoscopo. 

solid  angle  where  the  source*  has  an  intensity  of  1  Hefner;  1  hemi- 
spherical lumen,  for  instance,  is  the  light  radiating  through  a  hemisphere 
of  space1  from  a  source  of  1  Hefner. 

The  Legal  Standard  of  Light.1-  The  unit  of  each  simple  light  (blue, 
green,  etc.)  is  the1  quantity  of  the  light  of  the  same  kind  emitted  in  the 
normal  direction  by  a  square  centimeter  of  surface  of  molten  platinum 
at  the  temperature  of  solidification.  The  practical  unit  of  white*  light  is 
the  total  quantity  of  light  emitted  normally  by  the  same  surface*. 

The  Author's  Units  of  Light  Measured  Photographically. — 1  Touxcij 
is  a  light  or  otheT  radiation  which  will  produce  the  same1  e*t'fe*ct  upon 
Kodak  film  as  1  candle-power  of  carbon  filament  incandescent  light  of 
the  standard  brightness. 

1  Tan*!  i/  >//<((>•  xccuml  equals  tin*  effect  produced  as  above*  in  one 
second  at  a  distance*  of  1  meter. 

X.  1).  In  applying  this  photographic  measurement  to  .r-rays  or 
radium  rays,  in  comparison  with  incandescent  electric  light,  the  film 
.-hould  be  developed  in  the  regular  i  ray-developing  solutions  for  ten 

and  in  complete  darkness. 
The   Tests   Which   are   Applied   to   Electric   Lights,   Either   Arc   or 


058 


MKDICAL    KLKCTHICITY    AND    RONTGEN    KAYS 


Incandescent  Lamps.-  In  the  case  of  an  incandescent  lamp  it  is  of 
importance  to  test  its  resistance  when  cold.  For  this  purpose  the 
\Yheatstone  bridge  and  the  current  from  one  or  two  voltaic  cells  are 
employed. 

The  process  of  testing  a  lamp  at  work  employs  a  voltmeter  on  the 
principle  of  an  amperemeter  of  very  high  resistance  for  measuring  the 
difference  in  potential  between  the  lamp  terminal-.  The  lamp  may 
be  any  sort  of  an  electric  lamp:  incandescent,  arc,  or  vacuum  tube.  An 
amperemeter  is  also  required  for  measuring  the  strength  of  the  current, 
which  inay  be  turned  on  or  off  by  the  key.  A  storage-buttery  or  a  large 
batt'Ty  of  voltaic  cells  may  be  used  instead  of  the  dynamo. 

Thi-  number  of  candle-power  produced  by  the  lamp  must  be  tested 
by  a  suitable  photometer.  One  of  the  simplest  and  most  accurate  is 
familiarly  known  as  the  grease-spot  photometer.  A  sheet  of  paper 
with  a  grease-spot  in  the  center  is  held  up  b<  tween  the  standard  candle 
and  tin'  liirht  to  be  tested.  Looking  at  one  side  of  the  paper  the  spot, 
which  has  been  made  partlv  transparent,  appears  bright  if  the  light 
falling  upon  it  from  behind  is  more  powerful  than  the  light  falling  upon 
the  front  of  the  paper  around  the  spot.  The  paper  is  moved  back  and 
forth  between  the  two  lights  until  the  grease-spot  appears  neither  darker 

nor  lighter  than  the  sur- 
rounding paper.  Both  sides 
are  examined  to  make  sure 
of  this.  Then  the  distances 
from  the  paper  to  the  stand- 
ard candle  and  to  the  lamp 
are  measured  and  the  num- 
ber of  candle-power  varies 
directly  as  the  square  of 
the  distance  at  which  equal 
illumination  is  produced. 
Thus,  if  the  paper  is  four 
t  lines  a-  far  from  the  lamp 
as  it  is  from  the  standard 
candle,  the  lamp  is  giving 
a  huhi  of  If)  candle-power. 
Knowing  the  tuonf/cr  af 
\  he  termi- 
t  he  following: 


Th  •    ber  of  \\  ;;•  •  -  per  candle-pov  •  •:•.  I  he  higher  i-  the 

.   and    I"!'   I  he   same   ly]  «•  <  •!'  !a  mp   I  he   ]e>s  heal    is 
iial  i1  ill. 

lor  cyst oscopic  and  ot  her  endoscopic  work 

rip-  of  hliih   efficiency. 

•' ric    h^ht    bulbs    have    very    hi^h   efficiency;   for 

1  "  'V.  >    '      !'.  i|'      1<  l<  I     c.-|  ).     ;,  till     (  I.  !.")     Wat  t      per 

This  j,  because  the  filament    i-  ;it   a   hiirher 
temperature    '  ordmarv    electric    Imlit    buli>.      The   <^a~    retards 


PHOTOTHERAPY 


859 


the  evaporation  of  the  tungsten  and  convection  currents  carry  particles 
to  the  top  where  they  do  no  harm.  The  filament  is  in  a  compact  coil 
so  as  not  to  he  cooled  much  !>y  gas  currents. 


Fitl.  404. — Treatment  of  patient  with  100-candIe  power  lamp  and  paraholie  reflcrtor. 

Incandescent  Electric-light  Therapeutic  Lamps, — The  most  com- 
mon type  of  apparatus  for  the  application  of  light  is  an  incandes- 
cent lamp  mounted  in  some  sort  of  a  reflecting  device.  Figure  403  shows 


can  he  easily  adjusted  to  any  lamp  outlet,  and  can  l>e  held  either  by 
the  physician  or,  in  some  cases,  by  the  patient.     This  style  is  useful 


100.  —  Showing  u  .-houldcr  treatment   liv  clcctric-lijrht   h:ith. 


PHOTOTHERAPY 


GUI 


in  muscular  pains  due  to  cold,  such  as  what  is  commonly  known  as 
muscular  rheumatism.  It  is  also  useful  in  mild  cases  of  neuralgia.  Dif- 
ferent sixes  of  lamps  of  this  type  are  made  with  incandescent  bulbs  of 
various  power,  and  may  be  used  with  or  without  color  screens  and  with 
different  colored  bulbs. 

Figure  -t()")  illust  rates  a  slight  ly  more  elaborate  device  for  applying  t  he 
light  over  a  much  larger  area.  In  this  device  there  are  ten  incandescent 
lamps  each  of  Hi  candle-power.  It  is  hinged  at  the  central  part  so  that 
it  can  be  easily  placed  around  a  limb  or  over  the  shoulder.  On  the  top 
of  it  is  a  selector  switch,  so  that  five  or  ten  lamps  can  be  used,  accord- 
ing to  the  requirements  of  the  case. 

Figure  -107  shows  an  electric-light  bath  cabinet.  This  is  arranged  so 
that  the  entire  body,  with  the  exception  of  the  head,  is  subjected  to 
the  influence  of  from  forty  to  eighty  incandescent  lamps.  On  the  outr- 
side  of  the  cabinet  is  a  switchboard  so  that  various  sets  of  lamps  can  bo 
used.  Although  the  illustration  does  not  slow  it,  there  should  be  an 
arrangement  holding  two  strips  of  colored  glass,  one  of  red  and  one  of 
blue,  so  arranged  that  either  color  can  be  turned  in  front  of  the  rows  of 


incandescent  lamps,  or,  if  desired,  turned  out  of  [he  way  entirely  so  that 

1  he  phut  white  iiirht   is  used. 

I  igure  !'.".'  show>  a  di Herein  style,  in  u Inch  1  he  patient  is  placed  in  a 
reclining  position.  The  number  of  lurht-  is  ivu-ulated  by  mean-  of  selec- 
tor switches  on  the  outside  of  the  cabinet. 

Figure  IK)  illustrates  a  portable  elect  ric-liirht  cabinet  having  a  folding 
frame  and  curtains.  Thi-  makes  a  very  convenient  arrangement,  as 
when  noi  in  use  it  doe-,  not  take  up  am  space.  To  thi-  can  be  ea-ily 
added  the  red  and  blue  glass  screens.  The  patient  feel>  much  more  com- 
fortable than  with  his  head  fastened  by  a  \vooden  or  iron  cabinet. 

Figure  111  shows  a  combination  cabine!  m  which  are  placed  a  number 
of  incandescent  lamp-,  and  on  the  outside  are  mounted  three  arc  lights, 
the  object  of  this  arrangement  beinir  to  obtain  whatever  benefit  there 


MKDK   AL     i;i.i;<  TKKTi'Y     AM)     Ro.NTCiKX     KAYS 


PHOTOTHERAPY 


663 


may  bo  from  the  increased  (luautity  of  chcmic  rays  which  conic  from  an 
arc  light. 


I0v.or220vo!h 


lamp  \\'ith  non-focusing  reftortor. 


Figure    112  shows    an    arrangement    lioldmjz;  four   12o-cjin(llo-po\voi 


imps,  so  as  to  make  up  a  total  of  ">()()  candle-power.     It  is  also  arranged 


004 


MKDICAI.    KI.K(  THK  ITY    AND    HONTCKX    KAYS 


>o  that  in  place  of  usinu;  all  the  liirhts,  any  one  or  a  combination  may 
be  used  as  desired. 

I  itrures  }  \.)  and  414  illust  ra1(>  an  an'anji'enient  by  which  a  500-candlc- 
po\\'er  lamp   is   placed   in  a    horizontal   position  so   that   the  patient  re- 


PHOTOTHERAPY 


Colored  Screens.-  "When  colored  screens  arc  used,  ihev  are  generally 
made  <>!'  narrow  pieces  of  glass  held  together  in  a  metal  frame  (Fig.  -11")). 
The  object  of  this  is  to  prevent  breakage,  as  the  amount  of  heal  ab- 
sorbed in  the  glass  would  break  it  if  it  was  made  of  one  piece. 

Isolation  of  Calorific  Rays  of  Great  Wave-length  by  Quartz  Lenses.' 
-  The  hot  light  from  a  Fintsch  lamp  passes  through  a  circular  opening 
in  a  metal  screen,  then  2(5  cm.  further  through  a  quart/  lens  and  another 
diaphragm  and  a  second  quart/  lens,  all  at  the  same  distance  apart. 
The  lenses  have1  a  focal  length  of  27. :>  cm.  for  visible  rays:  their  diameter 
is  7.f>  cm.,  thickness  at  edge,  0.3  cm.,  and  at  middle,  O.S  cm.;  diaphragms 
are  1">  mm.;  the  central  parts  of  lenses  are  covered  with  black  paper 
2.")  mm.  The  greatest  wave-lengths  are  more  highly  refracted,  and  pass 


through  the  dit'l'erent  diaphragms  and  may  l>e  demonstrated  l>y  a  radi- 
omei  er. 

\-'.\\  remely  great  wave-leniil  hs  up  to  )•>()()  mm.  have  been  isolated  by 
!!.  Rubens  and  ( >.  \'on  Baeyer  from  the  light  produced  by  a  merciiry 
va])or  l.-mrp  filtered  through  black  paper. 

Electric  Arc  Therapeutic  Lamps.-  Fi<r.  Hii  illustrates  the  original 
Kin-en  arc-lamp  arrangement.  In  order  to  pr.'tccl  the  eye-  of  the 
assistants  from  the  irritating  effect  of  \\\>-  chemic  rays,  they  use  blue 
glas-e~.  Th"  appai'atus  contniiKMl  an  electric  arc  which  used  SO  am- 
peres; this  has  been  improved  and  Hinplifi''d.  the  mo>i  important  modi- 
iication  being  one  in  v/hich  practically  all  (lie  heal  rays  ar<  absorbed, 
-0  that  the  action  i-  due  entirely  to  luminous  j'ays.t  lie  cliemic  ray ;;  which 
actMni))a.ny  luminous  ray-,  and  some  ultraviol  '  rays.  The  condenser  is 
made-  of  (|uart /.  \\  hich  allows  practically  all  of  the  ull  ra  violet  rays  to  pass. 
The  metal  section  i-  filled  with,  water;  the  si  ctioli  nearest  to  the  arc  is 
arranged  fora  continual  circulation  of  water.  In  addition  to  this.  I  )r. 
Finsen  had  s]>ecial  compres>or>  made  of  ()ua!'t/.  which,  were  in  iirm 

1  II.  i;ul>ms  an.l  I!.  VV.  Wood,  Lc  Hn.liiiin,  Caris  Feb.,  I'.M  I.  p.   I  1. 
-'  J.c  UjuHuin,  A])ril,  I'.tlt.  p.  i:;<.'. 


606 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


contact  with  the  diseased  area.  These  compressors  were  also  either 
filled  with  water  or  arranged  for  a  continual  circulation  of  water.  With 
a  lamp  such  as  is  shown  in  Fig.  417  and  which  requires  2o  amperes  of 
current,  the  time  required  for  a  single  treatment  is  one  hour  and  ten 
minutes,  and,  as  a  rule,  improvement  is  not  expected  in  less  than  three 
months. 

Numerous  modifications  of  this  lamp  have  been  made;  with  the  idea 
of  increasing  its  efficiency. 

1'ig.  117  illustrates  the  latest  improvement  in  the  Finsen  ray  lamp. 
This  is  known  as  the  Finsen-lleyn  lamp.  With  this  apparatus  only 
one  case  can  be  t  reated  at  a  time,  but  instead  of  using  SO  or  100  amperes 
for  the  arc,  the  apparatus  requires  only  20  or  2">  amperes.  It  has  an 
automatic  arrangement  for  maintaining  the  arc  and  an  adjustment, 


so  that  the  length  of  the  arc  can  be  regulated.  It  is  mounted,  on  a 
heavv  iron  pedestal  ;md  arranged  with  a  counterweight,  so  that  it  can 
!>'•  ca.-ily  raised  or  lowered  and  brought  into  the  most  convenient  posi- 
tioti.  In  'hi-  apparatus  the  lenses  are  made  of  quart/,  so  lhat  all  the 
ultraviolet  ravs  which  are  generated  ]>v  the  arc  are  transmitted  to  the 
pat  iciil  v.  ii  h  vi-rv  lit  i  le  loss. 

1'i'j.    11s    illustrates    one    of    I  he   best    form-    of    arc-light    apparatus 

mad'    in  tin-  country;  all  the  adjustments  are  easilv  made.      The  auto- 

inatic    arratiL'i  ment    for    maintaining    the   arc    is    particularly    nice,    and 

v  no  attention  upon  the  part   of  the  operator.      There 

ndow  so  that    the  arc  can   be  readilv  seen   without   dis- 

oh-er\  er.      This   lamp    is    made    to    lake   from    10   to  )•>() 

an  i  pi  •'•  - .  'j  '  •  >  t  lie  special  requirement  s  of  the  case. 

I  In  •       illustrate  the  three  wavs   in    which   the,  rays  can 


PHOTOTHERAPY 


0(57 


bo  refloc'tod :  Fi^.  419,  a,  shows  the  arrangement  for  focusing  tlio  rays 
upon  a  particular  point;  Fia;.  41'.),  l>,  sliows  the  arrangement  to  cause  the 
rays  to  diverge;  Fia;.  419,  c,  to  throw  all  of  the  rays  into  one  parallel 
beam. 


TIL'.    117.— 


Iron  Electrode  Lamps.  -—It  was  found  that  by  employing  electrodes 
which  we're  made  of  iron  instead  of  carbon  the  proportion  of  ultraviolet 

rays  was  very  much  increased,  and  a  lamp  of  this  style  is  shown  by 
Fius.  I'JO  and  l'21  This  was  devised  by  Dr.  Bam:,  and  in  order  to 
operate  it.  it  was  found  necessary  to  luive  the  electrodes  and  the  entire 
casing  arranged  foi  a  cont  inual  circulation  of  water.  \\  hile  this  deyico 
is  yerv  efiicient,  it  is  a  rather  inconvenient  one  to  use. 


MiX 


MKDICAL   KI.KI  TKKITY    AND   KONTCKN    HAYS 


PHOTOTHERAPY 


009 


Fig.  422  illustrates  a  modification  of  the  Bang  lamp.  This  \vas 
devised  by  Dr.  Henry  (!.  Pil'fard,  of  \<>\v  York  City,  and  its  const  rue'tion 
is  such  that  no  water  circulation  is  required.  Owing  to  the  fuel  that  the 
arc:  is  only  o  inches  away  from  the  tissue  to  be  treated,  it  makes  a  most 
efficient  apparatus.  Iron  elec- 
trodes, however,  cannot  be  used  3 
on  an  alternating  current,  so  that 
in  order  to  use  this  lamp  on  an 
alternating  current  carbon  elec- 
trodes which  have  iron  filings  in 
them  are  used. 

The  carbon  arc  is  not  nearly  so 
rich  in  ultraviolet  rays  as  the  iron 
arc,  and  this  is  very  prettily  demon- 
st  rated  by  the  following  experiment : 
Place'  a  piece  of  solio  paper  in 
front  of  the  carbon  arc1  for  one 
minute.  You  will  notice  that  it 
will  become  slightly  discolored ;  now 
place  another  piece  of  solio  paper 
in  front  of  the  iron  arc,  and  in  the 
same  time  you  will  find  that  the 
paper  has  become  absolutely  black, 
this  indicating  that  with  the  iron 
arc  a  greater  proportion  of  chemic 
rays  are  generated. 

Tungsten  Electrode  Arc  Lamps. 
violet  light  treatment  then1  is  no  form  of  apparatus  which  for  cheapness, 
durability,  simplicity,  and  efficiency  can  in  any  degree  compete  with  a 


.. 

t 
•-cooled 


-W.  .1.  Turrell1  savs:  ''For  ultra- 


adjustable  arc  lamp  capable  of  carrying  20  amperes,  fitted  with 


rods  about  7  inches  long  and  ]  inch  square,  of  pure1  highlv  compressed 


1  .  \IIHT.  Jour.   Eloctrotheranv  and  Radiology,  vol.  xxxvi,   No.  4,  April.   1918. 


(170 


MEDICAL    KI.KCTHU  ITY    AND    ROXTGEN    KAYS 


Condenser  Spark-gap  Lamps.  One  therapeutic  and  physiologic 
use  of  condenser  discharges  is  in  the  production  of  visible  and  ultraviolet 
ray-.  A  Leyden  jar  '2  inches  in  diameter  and  with  a  total  length  of  10 
inches  may  have  one  armature  connected  with  one  pole  of  an  induction- 
coil  or  transformer  regulated  to  give  a  spark  about  4  inches  long.  The 
other  armature  of  the  jar  is  connected  with  the  other  pole  of  the  coil  or 
transformer.  Besides  the  above  connections  an  insulated  conducting 
cord  passes  from  each  pole  of  the  coil  or  from  each  of  the  Leyden  jar 
armatures  connected  with  it  to  each  terminal  of  a  series  spark-gap  made 
up  preferably  of  iron  knobs.  The  sparks  are  very  much  louder  and 
mure  brilliant  than  they  would  be  if  the  discharge  from  the  coil  passed 
through  the  series  gap  unmodified  by  the  condenser.  The  light  is  very 
rich  in  ultraviolet  rays. 

Such  a  lamp  has  been  made  with  magnesium  knobs,  but  this  metal 
vnlatili/es  readily  and  a  constant  shower  of  <parks  is  produced  which 
unfits  ir  for  this  use.  although  the  light  produced  is  especially  rich  in 
ultraviolet  rays. 

About  the  time  that  the  iron  arc  devised  by  Dr.  Hang  was  introduced. 
Dr.  ( lorl  described  a  lamp  based  upon  this  principle-  for  the  production 
of  ultraviolet  rays.  A  lamp  of  this  character  is  the  richest  source  of 
ultraviolet  rays,  that  we  have  at  the  present  time. 

As  originally  constructed  it  was  rather  inconvenient  to  use,  and  Dr. 
Henry  (1.  Piffard,  of  Xew  York  City,  devised  an  improvement  in  its 
construction.  Fig.  423  illustrates  this  improvement,  which  consists 
in  inakinir  the  spark-gap  so  that  the  distance  between  it  and  the  patient 
is  adjustable.  In  addition,  there  is  a  handle  on  the  side  of  it.  so  that 
the  operator  can  easily  and  safely  handle  it.  Dr.  Piffard  now  uses  this 


hoijt   the  quart/  window,  as  was  used   in    the  original  lamp,  as 

-  verv  much   more  active  wiihoul    the  quart/   window. 

it    in   this  way  by  noting   the  difference  in  time  that 

charges   when    the   ravs  from   tin-    lamp  are  directed 

.  i;  rt/  window  i-  in  front   of  the  lamp  it   discharges 

•  '  !'•'  owlv:  when   the  quart/   window   is  removed  the  elec- 

;   in-taiitly.  thu-  >howim_!  that    I  here  i.-  a   radiation 

the  quart/  doe-   not    transmit.      An  expo.-ure  of 

1    ,'•        ,   '  -  lamp  produces  a   very  mten-e  hyperenna. 

Ultraviolet    Kays    of    Exceedingly  Short   Wave-length.      I1,    l.enard 

and    ('.    Ham-  <   ive    di-eoven-d    rav-   of    les-    than    !»()   mil.    wave- 


PHOTOTHERAPY 


071 


length  in  the  light  from  a  condenser  spark-gap  with  a  tremendously 
powerful  current.  They  use  an  induct  ion-coil,  in  which  the  primary  is 
of  copper  wire  3  mm_  in  diameter,  around  an  iron  core  110  cm.  lonii  and 
',)  mm.  diameter.  There  are  three  layers  of  IWO  turns  each.  The  second- 
ary is  divided  into  four  sections,  in  each  of  which  are  32  layers  of  copper 
wire  1  mm.  in  diameter,  and  there  are  00  turns  in  each  layer.  The  pri- 
mary will  stand  a  current  of  00  amperes  for  fifteen  seconds.  The  primary 
condenser  has  a  variable  capacity  of  G  microfarads.  There  is  a  Wehnelt 
interrupter  with  a  nickel  electrode  and  a  jar  holding  GO  quarts  of  liquid. 
There  is  a  secondary  condenser  in  shunt  to  the  spark-gap.  The  spark- 
gap  has  aluminum  terminals  7  mm.  in  diameter  and  are  only  O.X  mm. 
apart.  The  current  regularly  employed  is  GO  amperes  and  200  volts. 
The  energy  at  each  discharge  is  1000  times  that  of  the  uniform  flow  of  an 
arc  lamp. 

The  light  from  such  an  apparatus  is  relatively  weak  in  visible  rays. 


bui  very  rich  in  ultraviolet  ray-,  especially  those  of  the  shortest  wave- 
length, even  as  short  as  00  mu. 

i  Uraviolei  rays  have  the  properly  of  causing  certain  chemicals 
and  minerals  to  fluoresce.  The  most  con  mon  test  for  the  presence  of 
ultraviolet  rays  is  the  fluorescence  they  produce  when  falling  upon  a 
piece  of  Y\  illemite.  When  the  tilt  ra violet  rays  strike  a  piece  of  \V:.'.<  - 
mite,  thev  cause  a  nm-t  beautiful  u'i'een  fluorescence.  In  order  to 


0*2  MKIHCAL    KI,i:<  TKMITY    AM)    KONTCiKN    KAYS 

determine  whether  the  fluorescence  is  due  to  ultraviolet  rays,  it  is  only 
necessity  to  place  a  piece  of  irlass  between  the  \Villemite  and  the  source 
of  radiation.  If  the  fluorescence  is  due  to  ultraviolet  rays,  the  <ilass 
will  cause  the  fluorescence  to  disappear  entirely:  if,  however,  the  appar- 
ent fluorescence  is  due  to  the  blue-violet  color  of  the  lili'ht,  then  the 
putting  of  the  piece  of  ida--  between  the  source  of  Ii»-h1  and  the  Wille- 
inite  will  not  cause  the  apparent  fluorescence  to  diminish.  Another 
simple  wa  v  of  test  nm'  is  to  take  a  piece  of  so  ho  paper  and  put  a  piece  of 
irlass  over  part  of  it  and  expose  the  covered  and  uncovered  portions  to 
the  source  of  liiiht.  If  the  radiation  is  principally  ultraviolet,  the 
.-olio  paper  uncovered  by  the  ,u'lass  will  blacken  in  a  .-hort  tune,  whereas 
the  paper  under  the  <dass  will  be  hardly  discolored.  Now  in  place 
of  the  Li'la.-,-  put  a  piece  of  quart/,  and  YOU  will  find,  if  the  radiation  is 
principally  ultraviolet,  that  the  paper  under  the  quart/  will  be  nearly 
a-  black  a.-  the  paper  not  covered  by  the  quart/. 


Kit:' tire  I'J  1  illust  rates  a  Cooper  Ilewitf  mercury  vapor  lamp  as  used  by 
the  author.  The  liuht  from  this  lamp  contains  no  red  rays.  It  is  a 
l.~>l)-c;indl<-po\\  er  liiiht  when  run  bv  the  110-voll  direct  current  with  a 
rheo-tat  to  reduce  the  current  to  1  or  ~>  ampere-. 

I'iu'Ut'e  !_'.")  -hows  this  lamp  in  use  in  the  treatment  of  a  case  of 
p  u  1  m  o  1 1 ;  1 1  • ; ;  I >  i  - 1  - . 

A  IIP  il  this  1,-mip  i-  what  i-  known  as  the  uviol  lamp  (Fiu1. 

1'J1'  .     Tlii  l-o  :i  mercury  vapor  lamp,  but  in-lead  of  iis'mo'  ordinary 

-    one    which    will    Iran-mil    higher   freipiencies  of 

lion  and  in- of  llie  ull  raviolel  ray  1  haul  he  ordinary  <rlass. 

Tlii-  !  n  I .  i  rope,  but  it  is  loo  early  to  stale  \vha1  it  -  I  hera- 

peljt  lc    '.    ;      . 

Kromayer's    Mercury    Vapor   Therapeutic   Lamps.      Professor    Kro- 


PHOTOTHERAPY 


073 


mayor,  of  Berlin,1  has  devised  mercury  vapor  lamps  of  suitable  form 
and  dimensions  for  contact  application  in  the  treatment  of  the  skin  or 
of  the  mucous  membrane  of  the  mouth,  urethra,  etc.  The  tube  carrying 
the  incandescent  mercury  vapor  is  made'  of  quartz,  so  as  to  tnuir-mit 
the  ultraviolet  rays  freely.  This  is  enclosed  in  a  metal  case  or  a  glass 
tube,  according  to  the  use  to  \vhich  the  lamp  is  to  be  put.  In  either 
case  there  is  a  circulation  of  water  between  the,  lamp  and  the  outer  case; 
and  the  portion  through  which  the  light  is  to  be  applied  to  the  patient 
is  also  made4  of  quartz.  Two  types  of  lamp  are  made;  one  is  of  high 
voltage  (120  to  150)  and  low  amperage  (3  to  4);  the  other  is  of  low 
voltage  (150  to  200)  compared  with  its  amperage  (2  to  20).  The 
advantages  claimed  for  it  are  that  it  has  from  three  to  five  times  as  great 


penetration  as  the  Finsen  (arc  lamp  with  carbon  electrodes")  and  a  greater 
superficial  action  than  the  dermo  arc  lam])  with  iron  electrodes. 

Therapeutic  Lamps  for  Internal  Use.-  Vacuum  light  tube-  have 
been  devised  by  St  rebel-  for  introduction  into  the  cervix,  the  urethra, 
or  the  mouth  for  the  therapeutic1  effect  of  iinhi. 

The  Nernst  Lamp.—  Figure  42',)  shows  the  latest  high-efficiency  incan- 
descent lamp,  which  was  discovered  by  l)r.  Nernst.  Thi>  differs  from 
the  usual  incandescent  lamp  in  that  the  incandescent  filament  is  not 

1  Miinrh.  Mcil.  Work.  I'M  id.  Xo.  in.  p.  ,377,  reviewed  in  Le  Radium.  April.  I'.inti. 
-  Dermatol.  Zeit.-fhrit't,  vol.  xi,  p.  77. 


074 


MEDICAL    ELECTRICITY    AND    KONTGEN    KAYS 


1  i_'.    i_',. — The  Kromayer  lamp:  n,  Lamp  ronnertion-pluK;  1>.  current  dirpetion-indi- 


[iluu  c'iniic<'tii)ii;  '/,  tube  connect  ion;  «,   winucd   nut    for  fixiiiL'  lamp  in  fork  ij;  f, 


luniii;  '/.  fork  luinp-lloldfT  (iii;i\    !»•  fixcil  in  an\    iio.-itioii) ;  h ,  i.  in-  and 


i'l'-i  foi  r-n    linn  ivui IT;    •'.  switi-li;  /.  rhc-ostal  lever;    m,  line  connection;  /(.  rlieostat  i  Han- 


.    ui'l   .Manufacturiim  Co.,   Newark) 


PHOTOTHERAPY 


075 


enclosed  in  a  vacuum,  but  exposed  to  the  air.  Apparently  this  lamp  is 
going  to  be  one  of  the  most  efficient  of  the  incandescent  style  used  for 
therapeutic  purposes,  as  the  actinic  power  is  great  and  the  heat  is  very 
much  less  in  proportion  than  when  the  usual  incandescent  lamps  are  used. 
As  this  is  also  a  new  type  of  lamp,  it  has  not  been  used  sufficiently  to 
give  an  idea  as  to  what  its  ultimate  therapeutic  value  will  be;  the  only 
disadvantage  is  that  it  can  only  be  operated  satisfactorily  on  the  alter- 
nating current  at  the  present  time.  The  heater  coil  of  platinum  wire 
alone  transmits  current  at  first  and.  becoming  incandescent,  heats  the 
glower,  which  is  a  small  rod  of  such  materials  as  zirconium  and  thorium. 


This  becomes  a  conductor  of  electricity  when  hot,  but  though  its  resist- 

ance is  diminished,  it  is  still  so  great  that  it  becomes  incandescent  itself. 

Ultraviolet  rays  are  generated  by  a  Crookes  tube  or  an  ./'-ray  tube, 

and  a  special  construction  has  been  devised  by  II.  Bierry,  Victor  Henri, 
and  Albert  Kane.1  The  tube  has  a  sort  of  pocket  of  quartz  tubing  in 
which  substances  may  be  placed  very  near  the  anticathode.  Carbo- 
hydrates undergo  the  same  changes  as  when  exposed  to  the  ultraviolet 
rays  from  a  mercury  vapor  lamp.  A  burn  appearing  within  twenty-four 
hours  after  an  .r-ray  exposure  is  doubtless  due  to  ultraviolet  rays  gene- 
rated by  the  .r-ray  tube.  This  source  of  injury  may  be  suppressed  by 
interposing  any  screen  opaque  to  ordinary  light. 

Effects  of  Ultraviolet  Rays  Upon  Gases.-  1.  There  are  produced 
uncharged  centers  of  condensation  which  are  due  to  impurities  in  the  gas. 

2.  P>oth  positive  and  negative  ions  are  produced  in  the  gas. 

3.  There  may  be  changes  in  the  gas  itself,  as  when  oxygen  is  changed  to 
ozone. 

The  effect  upon  chlorin  has  been  especially  studied  by  Ludlam.-  who 
finds  that  the  presence  of  a  trace1  of  chlorin  increases  the  ionixation  of 
the  air  under  the  influence  of  ultraviolet  ray-,  but  that  above  1  per  cent. 
the  more  chlorin  is  added  the  feebler  the  ioni/ation  becomes. 

The  t((trdrii>l(  (  rni/x  /'/<  x>/nluj/il  io)u'z(  tin  air,  rendering  it  a  conductor 


1  ('.  H.  <lrl;i  Sorirtr  dr 
'-  1'liil.  Mat:,  we,  I'.HL'. 


lx\.  .V-':1.,  April  1.  1<U1. 


07(1 


L    KI.KCTKICITV    AND    RiiXTCiEX    KAY* 


of  electricity,  and,  a-  might  be  expected,  Dember1  has  found  that  this 
effect  was  proportionately  greater  at  a  mountain  top  where  the  dust  in 
the  air  has  had  much  less  chance  to  reduce  the  amount  of  ultraviolet 
radiation. 

(  Itruiialet  Knifx  lonizt  Dielectric  Liquid*  and  Sonic  Dielectric  Solid*. — 
Soft  rubber,  which  is  ordinarily  such  a  good  insulator,  is  immediately  dis- 
integrated and  censes  to  be  a  non-conductor  of  high-frequency  currents; 
it  is.  therefore,  useless  for  insulating  wires  transmitting  these  currents. 
"J  lie  ultraviolet  ray.-  in  this  case  come  from  the  shower  of  sparklets 
covering  the  surface  of  the  wire  and  which  may  be  seen  if  the  outer  sur- 
face i-  touched  with  the  finger.  The  same  sparklets  may  be  drawn 
from  a  irlass  insulated  covering,  but  glass  is  not  affected  by  the  ultra- 
violet ray. 

The  li<rht  from  a  (Jeissler  tube  ionixes  neighboring  gases. 

An  insulated  sheet  of  aluminum  acquires  a  positive  charge  when  ex- 
posed to  the  ultraviolet  ray. 

PRINCIPLES    OF    PHOTOTHERAPY 

Sunlight  is  universally  recognized  as  a  powerful  bactericide.  Tuber- 
cle bacilli  were  destroyed  in  Bang's  experiments  by  a  .-ix-minute  expo- 
sure to  the  non-concentrated  light  from  a  iiO-ampere  arc  lamp  at  a  dis- 
tance of  :•)()  cm.  (12  inches),  and  Jansen  and  Bu.-ch  and  Xagelschmidt 
have  shown  the  destructive  effect  of  ult  ra violet  rays  upon  tubercular  and 
pneumonia  germs  inoculated  in  the  living  skin  or  cornea.  Klingmuller 
and  Halberstadter  found,  however,  that  small  pieces  of  lupus  tissue  ex- 
posed to  t  he  Fin.-en  lamp  for  seventy  minutes  still  produced  tuberculosis 
if  injected  into  a  rabbit '-  peritoneum. 

The  effect  of  phototherapy,  which  is  the  most  striking  modern  dis- 
covery, is  in  the  cure  of  lupus  vulgaris.  It  is  not  probable  that  the 
effect  is  due  simply  to  a  direct  bactericide  effect.  <)ther  factors  are  the 
generation  of  hvdrogen  peroxid,  ozone,  and  oxygen  in  tissues  exposed 
to  ultraviolet  Hid  it  and  the  development  of  new-formed,  connective  tissue 
whose  fibers  compress  and  destroy  the  tubercular  foci. 

The  til(nttl-/trf**nre  is  low  in  the  tropic-,  due  probably  to  a  va.-odila- 
tation  from  the  heat.  This  has  an  important  bearing  upon  tropical 
pathology.  ' 

Effect  of  Variously  Colored  Lights.  -Colored  lights  have  different 

effect-.       The    red    liu'lit.    t'o r    instance,    is    Stimulating,    whereas    the    blue 

li_dit    is  depressing.      Dr.  Nils  I!.   Finsen,  who  proposed   the  use  of  the 
arc  lamp  for  the  treatment   of  certain  .-kin  diseases,  called  attention  to 
.  l>v  I  Met  on,  of  .\  i  'W  Orleans,  almost  a  cent  urv  previously, 
i  i  very  much  better  when  the  ordinary  luminous 
i!    the   patient.      Till.-   was  accomplished   by   mean-  of 
al-o  cut  off  most  ot  tin   ordinary  chennc  ray.-.      In  order 
he    '•••'if    of   different    color-    the    iilass    of    \\hich    the  mcan- 
ratl    be    of    the    desired    ci  >1<  if.    -  if    a    glass   of    the 
placed  in  fn  ait    of  the  incain  le-cenl    lamp,  which  is 

inal  light  :  it  simply  cuts  off  all  ot  her  color-.      It 

doi      no'    io  tely.  but   it  does  -o  for  all  pract  ical  purposes,  and 

tin-  a'''i  ii       -  i--  placed    in    front    of   the   li-ht    \vill    be  just    the 

same  a-  thoiiu'h  '!.'    incandescent   lamp  \\ere  made  o|  blue  gla-s. 
1  i'i,\  -   /.  •  .-I  ,•  .  i:;,  I'.u:;.  L'UT. 

-  \\  .  [;.  Mn   _•    •         'I',',-       ill     I1), i  itm  :.<    J.Hir.  f.l  Sci,  ncc,  v,  L'1-'."),   1010. 


PHOTOTHERAPY  677 

It  is  a  well-known  fact  ihat  light  favors  oxidation  outside  of  the 
body,  and  as  it  penetrates  the  body  it  should  and  undoubtedly  does 
promote  oxidat  ion  and  chernie  changes  in  the  fluids  of  the  body.  Ac- 
cording to  Freund,  light  is  capable  of  changing  a  passive  congestion 
in'o  an  active  one.  so  that  light  is  indicated  in  chronic  congestive  con- 
ditions where1  the  light  can  be  applied  in  sufficient  power. 

Chemic  Effects  of  Ultraviolet  Rays.-  I'ltnivielet  rays  bring  about 
loss  of  nitrogen  in  certain  cheiuic  compounds  and  in  others  the  reverse, 
changing  nitrates  to  nitrites  or  vice  versa.1 

I'll raviolet  rays  change  starchy  solutions  into  maltose  and  dex- 
trin ''  and,  according  to  the  same  experimenter,  inulin  is  changed  into 
glucose  and  levulose. 

Ultraviolet  rays  destroy  the  properties  of  diastase  in  solution. 
Kay-;  of  a  wave-length  greater  than  M022  Angstrom  units  do  not  have  this 
effect,3 

Effect  of  Ultraviolet  Rays  Upon  the  Digestibility  of  Milk.— A  short 
exposure  has  no  effect,  a  longer  exposure  lessens  tryptic  digestibility,  and 
a  still  longer  expo-mv  restores  it.1 

ritraviolet  rays  change  saccharose  into  glucose  and  levulose: 
their  more  prolonged  action  produces  formaldeliyd  and  carbonic  oxid." 

I'll  raviolet  rays  from  a  (juartz  mercury  vapor  lamp  change  a  .-mall 
proportion  of  chlorophyll  dissolved  in  alcohol  and  water  into  urobilin- 
ogen." 

I  hraviolet  rays,  thi'ee  hours  and  a  half  exposure,  destroys  the  hemo- 
lytic  action  of  saponin.' 

I 'It  raviolet  ray-  destroy  amylase  and  invertase  :"m  malt  and  yeast  i ; 
the  formei1  is  more  sensitive,  and  in  a  mixture  it  may  be  destroyed  and 
the  invertin  be  only  attenuated." 

Biochemic  Effects  of  the  Ultraviolet  Ray.-  {'lira violet  rays  in 
thirty  minute-  to  two  and  one-half  hour.-  reduce  the  toxicitv  of  Stro- 
phant  ines. ' 

I  Itraviolet  rays  ([iiickly  destroy  the  venom  of  the  cobra,  but  have 
much  less  effect  upon  ant ivenomous  serum.1" 

I  Itraviolet  rays  have  an  effect  upon  the  \\a--ermann  reaction  for 
syphilis  analogous  to  their  effect  upon  tuberculin.  They  do  not  effecl 
the  properties  ot  -era  rich  in  antibodies,  hut  antigen--;  and  antibodies  no 
It  inger  lix  alexins." 

ISaeteria  killed  by  ultraviolet  i-ays  preserve  their  agglutinins  intact, 
and  can  be  used  for  serodiagnosis.12 


•  ]..  Ma>«>!,  I!,!.]..  902.  March  27    I!.H1 

'  II.  Aiiiilhon,  [hiil.,  :!9S.  |Vh.  |:;.  i<u  i. 

-  •'    T.-l:mVi>,  C.  i;.  ,!«•  I;,  >,»-.  dc  [iinl.,  Ixix.  :i21.  Xov.  .'.  I'.UM. 

H'-nri  lii   rr.     Victor  II,  mi.  and  Allu-n    H.-IIK-.  lijid.,  lx\.  000,  .!uti«'  3,  1911.  nii-l 
C.  1!.  'i"  I'Ac.Mil.  i!cs  Sciences,  [(>2U.  Juno  li.  191  1 

(;  II.  P.ierry  .uni  ,).  L-irfi'iiii  r  des  li'incel-.  C.  \\.  <]<•  I'Acrul.  <lc<  Scinioi  s.  cliii.  124, 
July  !0.   1911. 

7  'I  r.  Solacolu,  <    .  I!    ilc  hi  Soc.  r!e  Mi-!..  l\xi.  'Jill. 

'A.  ClijHiclianl   and    \\.  Maxonie.  C.   \l.  iii    '      I'Acad.  dcs  Scinu-es.   c-lii.  17H9. 
Juni     12,    I'M  1. 

'  1  '•  Hanii'luiH-hi.  c.  i;.  ,!,-  la  SOP.  d,    I'.ii  ]  .  Ixxi.  200,  July,  1911. 
1..  Ma.-til,  Ibid..  Is:!.  July  2:5,   I'.M  i. 
M:iurice  Breton.  I!. id..  1\\.  ,107,  April   1 .  191  1 . 

II.  Stussaiio  and  L.  Lain:iti«'.  (  ' .  i! ,  .i>   1"  \cadi  inir  des  Scienci  s,  rlii.  t ',2:1.  March. 
191  1. 


078  MEDICAL    ELECTRICITY    AM)    KONTGEN    RAYS 

I  Itraviolot  rays  destroy  the  antitryptic  properties  of  human  blood- 
serum.' 

Effect  of  Ultraviolet  Rays  Upon  Anaphylaxis.— Horse  serum,  ex- 
posed to  the  radiation  for  two  and  one-half  to  three  and  one-half  hours, 
shows  a  destruction  of  its  antisensibilitins  without  lo.->  of  its  precipitoge- 
nous  proper!  ies.- 

Effect  of  Ultraviolet  Rays  Upon  Tubercle  Bacilli  and  Tuberculin.— 
A  short  expo-ure  attenuates  the  bacilli  in  a  culture  and  a  lonti  exposure 
kill:-  them.  Tuberculin  lo-e-  its  properties,  and  this  effect  is  more 
rapidly  produced  in  the  air  than  in  a  vacuum/' 

Effect  of  Ultraviolet  Rays  Upon  Tuberculin  and  Antitubercular  Sera. 
-  It  render-  tubeivulin  inactive,  but  does  not  modify  its  precipitogenous 
property.  Serum,  however,  quickly  loses  its  precipitant  property.4 

Influence  of  Light  in  Causing  Hyperglobuly  at  High  Altitudes. — 
The  accumulation  ot  Mood-cell-  in  the  peri  pin  ml  vessels  which  ordinarily 
take.-  place  at  hi<di  altitudes  may.  according  to  T.  ( iayda's  experiments 
upon  rabbit-,  be  prevented  by  exclusion  of  1'mht." 

The  effects  of  ultraviolet  rays  upon  micro-oiganisms  have  been 
exhau.-tivelv  -tudied  by  Mine.  V.  Henri  ( 'ernovodeanu  and  Victor  Henri, 
at  the  phv-iolo^ir  laboratories  of  the  Sorbonne  and  of  the  Pasteur 
In-tit  ute.' 

A>  tar  back  as  1S77  Downes  and  Blunt1  experimented  upon  the  bac- 
tericide  effect  of  liirht  and  found  that  the  mo>t  refrangible  was  the  most 
active.  Ainonu'  other-  Houx.  (  leis.-ler.  and  Mar-hall  pursued  further 
studies,  which  preceded  Fin-en's  \vork.  The  latter  in  IS',)'.*  to  190"),  with 
hi-  ])upils.  S.  Baiiir.  V.  Bie.  A.  I.arsen.  ('..  Dreyer.  II.  .Ian-en.  ().  .Jensen, 
('..  Bu-ck.  Schmidt-Nielsen,  A.  Heyn.  and  K.  Kol-ter.  -tudied  the  effect 
u])on  yeasts.  fun«ii.  ameba'.  infusoria,  and  different  animal  tissue's. 

I  in-en  and  hi-  pupil-  -howed  .that  our  >unli^ht  i-  quite  ]>oor  in 
ultraviolet  rays,  due  to  absorption  by  the  air.  The  arc  li^ht  is  rich  in 
ultraviolet  ray-,  and  \\ilh  the  positive  carbon  21  and  the  negative  12 
mm.  in  diameter  and  M5  to  SO  amperes,  \\ith  an  average  of  50  volts. 
the  liul.t  beinu'  concentrated  upon  a  Mirface  12  mm.  in  diameter  by  a 
quart/  !cn-  7  cm.  in  diameter,  and  with  the  heat  filtered  out  by  a  layer 
of  water  in  a  vessel  with  quart/  walls,  tin-  liuht  kills  the  Bacillus  prodijji- 
o-u-  iii  two  or  three  seconds.  Arc  lamps  with  metallic  electrodes,  espe- 
cially iriiii.  are  maiiv  time-  more  effective  than  1  hose  with  carbons. 

The  interpo.-it ioii  of  even  a  thin  -heel  of  ula--.  and  the  admixture 
of  bouillon,  pepton.  albumin,  uelalin.  or  any  other  oruanic  colloids  to 
the  water,  anv.-ts  the  maior  ])ail  of  the  ultraviolet  rays,  while  perhaps 
perfei-tly  ti'an-jjarent  to  the  visible  rav>.  \ariou-  nerm-  >how  different 
d<'Ui'ee>  of  -u-cepl  ibilit  y  youiiu  culture-  are  more  sensitive  than  old 
OIK-.  ;iiid  the  -pure-  ,-u-c  three  to  five  time-  a-  re-i-tant  a-  the  u'erm-. 
I'.i,;  culture-  of  any  of  them  may  be  -terili/ed  by  exposure  to  the  ultra- 
violet ray.  The  time  required  i-  from  a  few  seconds  to  a  few  minutes. 


PHOTOTHERAPY 


079 


Those-  oxporiments  also  showed  that  the  effect  was  due  directly  to  the 
light,  and  takes  place  in  the  absence  of  heat  or  oxygen. 

A  later  development  dates  from  100"),  with  the  discovery  of  the  sen- 
sibilization  of  animal  tissues  by  means  of  substances  like  anilin  dyes 
containing  iodin  or  bromin,  which  is  liberated  in  the  tissues  by  the  ultra- 
violet ray  and  adds  to  the  effect.  For  example,  a  hypodermic  injection 
of  2  milligrammes  of  hematoporphyrin  into  a  white  mouse  produces  no 
inconvenience  while  in  the  dark,  but  kills  in  three  hours'  exposure  to  arc 
light. 

And  the  final  process  consisted  in  the  introduction  of  the  mercury 
vapor  arc  in  a  tube  of  quartz,  like  Kromayer's,  generating  the  ultraviolet 
ray  much  more  powerfully  than  any  of  the  open  arc  lamps. 

The  therapeutic  use  of  the  ultraviolet  ray  is  due  to  Finsen,  Preisz, 
Seiffert,  and  others,  who  applied  it  to  the  sterilization  of  milk,  and  ( 'our- 
inont  and  Nosier  to  the  sterilization  of  considerable  quantities  of  water. 

It  has  long  been  known  that  the  most  rapid  vibrations  among  the 
ultraviolet  rays  are  the  most  active,  and  Thiele  and  Wolf1  proved  this 
by  the  use  of  a  screen  of  blue  rock  salt,  which  arrested  the  heat  rays,  the 
visible  rays,  and  the  ultraviolet  of  a  wave-length  greater  than  330  mu., 
but  which  was  perfectly  transparent  to  ultraviolet  rays  of  a  wave- 
length from  380  to  210  mu. 

Measurement  of  the  Intensity  of  the  Ultraviolet  Rays. — The  in- 
tensity of  the  different  wave-lengths  generated  by  an  ultraviolet  lamp 
may  be  measured  by  a  delicate1  thormopylc  and  a  quartz  lens  or  differ- 
ently absorbent  screens.  A  relative  measure  of  the  entire  ultraviolet 
radiation  is  obtained  by  measuring  the  ionization  of  gases  and  electrifi- 
cation of  metallic  surface-;  very  much  as  radio-activity  is  measured. 
Becquerol's  method,  modified  by  Kder,  is  based  upon  the  amount  of 
calomel  precipitated  from  a  mixture  of  ammonium  oxalate  and  bichlorid 
of  mercury.1' 

The  sterilizing  effect  upon  a  twelve-  or  twenty-four-hour-old  culture 
of  colon  bacilli  upon  agar  is  employed  by  Henri  (  Vrnovodeanu  and  Henri 
(1.  i'.).  The  bacilli  are  carefully  scraped  off  without  any  lumps  of  agar 
and  are  emulsified  in  distilled  water  and  exposed  at  a  distance  of  20  cm. 
from  the  lamp.  This  reaction  is  almost  exclusively  limited  to  the  invis- 
ible ultraviolet  rays,  .and  the  interposition  of  a  shoot  of  colorless  glass  1 
mm.  ( ,,'.-,  inch)  thick  makes  it  take  1000  or  2000  times  as  long  to  sterilize 
the  emulsion  of  bacilli.  An  exposure  of  one  second  with  a  certain  mer- 
cury vapor  lamp  with  140  volts  and  4.7  amperes  produces  complete 
storilizat  ion,  while  300  seconds  are  required  wit  h  23  volts  and  2.3  ampere-. 
The  photographic  effect  upon  nitrate  of  silver  paper  (solio  matt'  is 
employed  by  the  same  authors.  This  paper,  when  exposed  to  the  light 
from  a  mercury  vapor  lamp,  is  chiefly  acted  upon  by  the  ultraviolet 
rays,  only  one-eighth  of  the  effect  boinu  due  to  the  visible  rays. 

The  time  required  to  produce  an  equal  discoloration  is  inversely 
proportional  to  the  bactericidal  activity.  A  moans  of  arriving  at  the 
proper  color  of  the  paper  is  by  comparison  with  the  action  upon  iodid  of 
potassium.  Ilonri-(  'ernovodeanu  and  Henri  place  0  c.c.  of  .">  per  cent, 
solution  of  2.1  per  cent .  sulphuric  acid  in  a  gla>s  dish.  3  cm.  in  diameter,  at 
a  distance  of  20  cm.  below  the  lamp,  and  determine  the  time  required 
to  liberate  0.1")  milligramme  of  iodin. 


080 


MEDICAL    ELKCTHICITY    AND    RONTCEN    KAYS 


\\ater  is  very  transparent  to  the  ultraviolet  ray.  even  more  so  than 
air.  and  through  cither  medium  the  time  required  to  produce  an  equal 
effect  increase-  about  as  (lie  -quare  of  the  distance  from  the  lain]). 

The  bactericidal  effect  i-  neither  slowed  nor  hastened  materially  by 
the  temperature  at  \\hich  the  ultraviolet  ray  is  applied.  In  this  it 
follow-  ( ioldl  >eru'-  law  reuardiim'  true  photochemic  reactions.1  This  is 
entirely  contrary  to  ordinary  cheinic  reactions,  which  art'  many  times 
more  act  ive  at  hi^h  tempera t  ure. 

The  bactericidal  effect  of  ultraviolet  ray-  i-  the  -anie  whether  the 
enml-ion  i-  a  liijiiid  or  is  fro/en  into  ice.  providhm  the  latter  is  trans- 
parent . 

h  was  formerly  -uppo-ed  that  the  bactericidal  effect  of  the  ultra- 
*  rays  wa-  due  to  peroxid  of  hydrou'en  uvnerated  by  the  rays,  but 
bacteria  are  killed  just  a-  quickly  in  the  al»en<v  of  oxygen  or  even  in  a 
vacuum,  and  Henri-C'ernovodeanii  and  Henri  ha\'e  mea.-ured  the  quan- 
tity i'!  peroxid  ot  hydrogen  uenera'ed  during  the  few  >ecoiids  required  to 
/e  an  emul-ion  of  (:oioii  bacilli  and  iind  it  to  be  an  infinitesimal 
trace. 

I  )i  fie  rent  ( 'manic  substances  are  variously  susceptible  to  change  under 

the  influence  of  ultraviolet  rays.       (duco-e  is  much  more  resistant  than 

levulose.  and  >ome  fatly  acid-  are  more  quickly  -aponified  than  other-. 

•ancer   cell-   in   mice  are  more  susceptible   than   The   normal   cells. 

[(.  VniovodeailU   and    Xe^re.)      The   \'isible   effect    iwith    the   ultramicro- 


in.       M  icn  IH  ii'ii-anHins  ot  consider- 


:  •          "       i  in  M  o)!a-m   i-  c<  (aiiuia  i  H 


-!/>  .      ra nieces,   and  I  lie  while  Mood-cell-  and  I  lie  white  ol  eu;! 


all   show   thi-  effect    \\hen   expo-ed   to   the  ultra- 


mal    cell-   it)'   all    kind-   are    tixed    by    exposure   to 

Thil-,  the    red    blood-cell-  no  lonuer  lo-e  their  heino- 

ii   of  wa ' er.      The   mien  >he-   are   n H  >re  difficult    to 

•'••in-:  and  it   the  expo-ure  ha-  been  prolonged,  the 

'    ilai    di-intenrat  i' MI.      'Irani'-    -taimnji    no   longer 

1    '       rid   re-i-1  ance  of  nil  M  T<-|I  •  i  lacilli  i-  li  >-i . 

Sterilizatirin  of  Water  and  Milk    bv  the  Ultraviolet  Rays.     Water, 
red    ]  icrfeci  |\     t  ran-parent     1  iy    iilterintr,    can    be 


PHOTOTHERAPY  G81 

completely  sterilized  by  passing  through  ;ui  apparatus  in  which  it  must 
come  in  contact  three  separate  limes  with  the  quart/  plate  separating 
it  from  the  space  in  which  a  mercury  vapor  quart/  lamp  is  in  operation. 
The  lain])  in  the  apparatus  shown  in  Fig.  430  requires  a  current  of  72") 
watts  ami  will  sterili/e  loO.OOO  gallons  of  water  ])er  day.  Milk  cannot 
be  sterili/ed  by  the  ultraviolet  rays  exce])t  in  such  thin  layers  as  to  be 
t  ransj)arent ,  and  no  very  practicable  apparatus  is  yet  in  use  for  thi- 
purpose. 

The  Physiologic  Effect  of  a  Local  Application  of  the  Ultraviolet 
Ray. — The  effort  is  chiefly  confined  to  the  skin,  and  consists  of  an 
erythema  with  a  papular  swelling  which  often  develops  into  a  blister 
in  t  he  course  of  twelve  to  twenty-four  hours.  The  blister  dries  and  when 
the  crust  falls  off  no  scar  is  found.  Meironsky1  finds  that  the  ultra- 
violet light  stimulates  epithelial  cells  and  increases  their  metabolism, 
but  strong  applications  cause  degeneration  and  blistering.  There  is  a 
congestion  of  the  blood-vessels  with  emigration  of  leukocytes  and 
extravasations  of  blood  into  the  tissues.  There  is  the  increase  in  fibrous 
tissue  cells  already  noted  and  a  swelling  of  the  connective-tissue  si  roma. 
A  deposit  of  pigment  granules  may  take  place  in  all  the  different  layers 
of  epit  helia. 

( iranulating  surfaces  heal  much  faster  li  treated  by  ult  ra violet  light . 

Blood  circulating  in  the  tissues  limits  the  effect  of  the  ultraviolet 
ray  to  the  most  superficial  layers  of  the  skin.  Fin-en  blanched  the 
skin  by  pressing  a  quart/  lens  upon  it,  and  other.-  have  injected  adre- 
nalin or  introduced  the  latter  by  electrolysis. 

Ultraviolet  Light. — Palms,  soles,  and  scalp  will  stand,  according  to 
(  'ora  Smith  King.-  about  twice  as  much  as  more  sensitive  parts.  For 
treatment  the  scalp  must  be  entirely  denuded  of  hair  by  shaving  or  de- 
pilation.  ('rusts  and  scales  have  to  be  removed.  The  therapeutic 
effects  are  to  activate  normal  cell  growth  and  function,  inhibit  ab- 
normal cell  UTowth  and  function:  also;  1,  bactericidal:  2,  oxidi/ing; 
o,  analgesic:  I,  ant  iprurit  ic:  •")  soporific:  (>,  stimulating  to  granulating 
wounds;  7.  markedly  helpful  to  metabolism.  Also  1,  sens*1  of  "genial 
irlow"  even  through  a  water-cooled  burner  that  would  feel  icy  to 
the  skin.  Therefore  the  physical  effect  inn--;  in1  warming:  2,  they 
"warm"  to  hyperemia  and,  with  intensive  dosage,  even  to  the  bli-ter- 
inn;  point,  yet  without  a  -ensation  of  heal  radiation.  Ilyperemia  de- 
velops in  i  wo  to  -ix  hours  and  blister  in  seventy-two  hours,  luslowly 
declines,  with  desquamation,  always  without  scarring,  leaving  new  epi- 
dermis more  delicate  t  han  before,  and  hence  i-  popular  t<  >r  co-met  ic  el'leci . 
ivjinmir  the  skin  and  causing  coarse  pores  io  contract  and  empty.  This 
doe-  not  agree  with  the  observed  fact  that  a  lady  -  -km  may  be  of  finest 
and  permanently  coarsened  and  somewhat  reddi  tied 
sun-burn  which  is  due  chiefly  to  ultraviolet  ray-, 
brown,  coppery  brown,  and  finally  mahogany:  this 
is  accompanied  bv  bactericide  effect,  curmu  acne  and  boils. 

Sensibilization  of  the  Tissues  to  Light.  The  tissues  may  be 
rendered  more  sensitive  to  liu'ht  ravs  bv  the  injection  of  substances 
like  ervthrosin.  This  substance1  render-  the  tissues  sensitive  to  the 
rays,  from  the  greenish-yellow  to  the  yellow-orange  inclusive,  which 
ordinarilv  do  not  affect  t  hi1  tissues.  The  effect  of  a  Fin-en  treatment  is 


6S2  MKDK  AI.    KI.KeTKK  1TY    AND    RoNTCF.N     HAYS 

thus  obtained  in  one-fourth  in  one-thud  the  ordinary  time.  Dreyer1 
introduced  the  use  of  this  substance  following  the  experiments  of  Tap- 
peiner  and  Kaah  upon  proto/oa  and  animal  tissues.  The  value  of  the 
method,  however,  ha.-  lieeii  -eriou.-lv  (juestioned. 

Ko-in  has  been  u-ed  in  ihe  same  \vav  as  er\'thi'osin 2  with  favorable 
results  in  tubercular,  syphilitic,  and  cancerous  conditions  of  the  skin. 
Siraiib'.-  theory  is  that  rosin  generates  hydrogen  peroxid  under  the 
influence  of  light . 

Morton's  nieihod  of  sensibili/at  ion  of  the  tissues  to  light  and  other 

radiations  by  the  internal  administration  of  <|uinin   or  fluoresein  is  still 

•  .  and  i  he  author'.-  own  observations  do  not   confirm  its  value. 

Sonvntino  paint-  the  surface  of  the  lupus  with  an  ar.-eniate.  which 
seem-  to  allow  the  rays  to  penetrate  the  tissues, 

Forschhammer*  used  the  following  solution: 


Ti  was  injected  ;}.">( I  times  altogether  in  I'M  cases  of  lupus  under 
phototherapy  at  Copenhagen.  It  produced  no  discomfort  until  the 
expo.-ui'e  to  the  powerful  li^ht  took  place,  four  to  eight  hours  after 
the  injection.  The  reaction  to  Finsen  hidit  was  very  violent,  more 
lik>'  a  case  of  phlegmon  than  like  the  ordinary  reaction  after  a  similar 
exposure .  Kxperiments  with  different  dose-  produced  either  no  effect 
or  a  most  violent  one.  The  therapeutic  effect  seemed  to  be  bad. 

The  Effect  of  Ultraviolet  Rays  Upon  the  Eye.  This  is  a  subject 
which  has  been  studied  in  detail  by  Birch-Ilirschfeld.8  The  rays  in 
hi-  experiment-  were  from  a  variety  of  sources;  a  powerful  arc  lamp 
with  carbon  electrodes;  a  dcrino  lamp  with  iron  electrodes;  sparks 
from  an  electrostatic  induction  apparatus;  sunlight.  Quart/  lenses 
were  used  to  concent  rate  the  ra v.-  in  the  eye. 

Tin-    ultraviolet    ray.-    are    laruelv    arrested    bv    the    crystalline    lens, 

(his    protects    the    retina    from    anv    marked   effect.      An    e\  e   from 

which  the  crvstalline  lens  has  been   removed,  for  experiment   or  for  the 

cure  DI    cataract,   loses  this    natural   protection.      The  especial  changes 

from   exposure   to  a    powerful   aic   lamp   under  these  cir- 

•i  -    an-    ;i    loss   of    chroma!  in    in    the   ganglionic    cells   ami    the 

•  tit   of  vacuoles  in  the  protoplasm  oi   these  cell.-.      The  nuclei 
-    me    ci  I).-    are    large   and    clearly   defined    and    have   a    vaeuolar 

a    verv   di-tiiici    nucleolu.-.      l.verv   other  part    of  the 

I'e'    :.••  cted    to    a    .-Ilidit    extent.        Ihese    change.-    ma\'    be    noticed 

a'  oi     i  tak<    i  wenty-lour  hours  to  develop.      They  are  recovered 

I .  . !  H  i-  ,  •  oi  ill1  normal  eve  to  I  he  powerful  a  re  lamp-  used  in  phot  o- 
'  : . '  ;  '•  e  -  a  I  -  o  important  change.-  i  n  all  (lie  ocular  1 1 1  e  <  h  a  except 

':c-  hicli    remain.-    ;  r.-i  i.-pa  rent .       I  here   are   conjunc- 

cli  iiidine--    of    the   cornea    and    part  la  1   de-quaniat  ion   and   soine- 

I).  I         '    •      /•    I-r-li.,   iV.    N'.,.    Id. 

'!     :  ii.l   I<-ionek,  Miincl,.  M,, I.  \Yncl,..   mo:!,  \,,.   17. 

-•  III     m;i]  itti   V.-li'T.   i   ilf||:i    pi-lie,    lilllti,    No.    1 

•  I  )•    ;'    cl,.    M,  ,|     \\orli.,  Sept.    I,',.    I'.KIi. 

•  An-li.  i.  Ht.I.tl  u'ic.  vol.  Iviii    n    Ifi'.i. 


PHOTOTHKKAl'Y  083 

times  karyokinesis  and  vacuoli/at  ion  of  Its  epithelium;  iritis  and  fibrinous 
exudation  in  the  anterior  and  posterior  chambers  of  the  eye.  These 
conditions  disap|)ear  after  a  few  days,  but  slight  corneal  trouble,  hypere- 
mia,  and  the  vacuoli/ation  of  the  ganglionic  cells  of  the  retina  may 
remain  for  a  long  time. 

Sunlight  is  very  rich  in  ultraviolet  rays  under  certain  special  con- 
ditions. The  reflected  idare  from  snowfields  upon  high  mountain.-  in 
winter  affords  an  example,  and  the  eves  often  suffer  in  consequence. 

The  ultraviolet  rays  in  the  blinding  flash  of  light  to  which  electri- 
cians are  sometimes  exposed  from  accidental  short-circuiting  produce 
important  effects  upon  the  eye.  There  is  often  temporarv  blindness 
lasting  a  few  minutes  or  a  few  hours,  and  sometimes  there  is  ervthrop- 
sia:  all  objects,  ('specially  bright  ones,  appear  red.  After  a  few  hours 
the  conjunctiva  becomes  red  and  swollen  with  a  feeling  as  if  the  eyes 
were  full  of  sand.  Keratitis  and  iritis  develop.  These  conditions  all 
disappear  in  a  few  days,  but  in  some  of  t  hese  cases  t  here  are  also  changes 
in  the  retina  which  may  last  for  a  Ion::  time  or  even  be  permanent,  and 
which  are  perhaps  not  due  to  the  ultraviolet  rays  alone. 

The  effect  of  a  stroke  of  lightning  upon  the  eye  is  often  very  seven  — 
the  crystalline  lens  may  become  opaque  (cataract),  and  there  mav  be 
atrophy  of  the  optic  nerve  or  slighter  nervous  changes.  These  do  not 
appear  to  be  due  to  the  influence  of  light  alone. 

Ordinary  eyeglasses  protect  the  eye  perfectly  from  the  rays  which 
are.  strictly  speaking,  ultraviolet  (beyond  the  visible  extremity  of  the 
spectrum),  but  some  of  the  visible  rays  near  the  violet  end  of  the  spec- 
trum produce  similar  effects.  These  rays  may  be  guarded  airainst  by 
smoked  glasses  or  yellow  glasses,  but  not  by  blue  glasses. 

The  ultraviolet  rays  destroy  bacteria  in  the  eye  either  in  front  of  or 
behind  the  crystalline  lens,  but  the  eye  would  be  badly  injured  by  the 
necessary  length  and  strength  of  exposure. 

Cnnjiinctiritix  Due  to  Electric  Lit/hi. — This  occurs  quite  frequently 
amonii1  those  who  regulate  or  repair  arc  lamps,  and  under  conditions 
which  make  it  evident  that  the  trouble  is  caused  by  the  light  and  not 
bv  the  heat  rays.  We  believe  also  that  it  is  due  to  the  rays  at  the  violet 
end  of  the  spectrum  and  to  the  ultraviolet  rays.  The  affection  is  only 
temporary  and  the  treatment  is  by  cold  affusions  of  boric  acid  solution. 

More  serious  cases  have  been  observed  by  Fuchs  and  are  complicated 
bv  myosis.  slight  opacities,  and  erosions  of  the  cornea,  but  these  also 
are  recovered  from  in  a  few  davs.  Harold  (Jrimsdale1  has  given  detailed 
report-  of  several  cases.  One  case  was  in  a  workman  who  had  profuse 
lachrymation  and  redness  and  edema  of  the  conjunctiva  with  several 
little  papules,  \ision  was  notablv  diminished.  He  had  repaired  an 
an-  lamp  which  remained  lighted  while  he  was  working  at  it.  Photo- 
phobia and  i  he  other  symptoms  enumerate!  1  above  had  come  on  within 
a  few  hour-.  Rapid  recovery  followed  the  use  of  cocam  and  cold 
at'fu.-ions  of  boric  acid  solution.  Smoked  glasses  had  to 
sonic  t  nne  afterward. 

Another  <>/  (rmnxduU  '*  CIIHCH  followed  an 
An  engineer  was  arranging  some  incandescent  ', 
occurred.  There  was  a  Hash  of  light  lasting  an  exceedingly  short  time. 
The  man  felt  blinded,  but  was  able  to  see  directly  afterward.  There 
was  severe  pain  lasting  for  a  few  minute-,  but  toward  night  all  the 
1  I'IV>M-  Medicale,  April  •_'•_',  \W2. 


!)M  MKDK  Al,    K!.K«TKI<  ITY    -VXD    HoNTCEN    KAYS 

.-ymptoms  had  disappeared  for  the  time.  He  awoke  in  the  niidit, 
h'  '•.'.  ever,  with  ail  intolerable  it  chin.U  of  the  eyelids,  as  if  their  mUCOUS  sur- 
face \vere  covered  wit  ll  salld.  There  Was  lachrymal  ion.  1)111  no  blepha- 

ro>pa>m  or  marki  d  photophobia.  The  palpebral  conjunctiva  was  con- 
Li'eMed  and  covered  \\iih  papules.  Yi-ion  was  iKH'iiuil.  ( 'ocain  and 
cold  affusions  of  lioric  acid  solution  ei't'ecie,)  ;i  cure  1!:  I  \vn  da\'S. 

I']  e  p resell i  author  oner  pel-formed  an  experinieni  in  which  a  heavy 
the  hand  was  used  to  -hurl  circuit  the  110- 

Ili'ect    current.        I'li'i'i     \\'as   a    wonderful    lla-h  ot   liLi'ht   and  about 

f   tin      sh-el    \v:  l;  lly  consumed :    not    merely    melted,    but 

[  di.--ipat  ed.      'I  he  aut hor  's  face  was  about    15  in  dies  from 

:  [iroduced.    but     thei'e    \\;;-    no    pel'Ceptible    effect 

eves.      I'nfortunat el\'.   he  is  unable  to  recall  \vliether  lu-  had 

at    i  he  time  or  not.      Plain   irla.-s  doe-   not    arrest    mucli 

ibje  li^'li? .  but    11    does  si  op  a  ,i:reai    pal'!   of   she  iin'isible  ultra- 

t  rays.  :,!L  hly  act  inie. 

Physiologic  Effects  of  Ultraviolet  Ray  Baths.-  Those   baths  in 

.  :  '      :    e  the  si  Mii'ce  of    illuminai  ion    ui\  e    the    patient    the 

•    oi    t!n     ultraviolet   rays   as   well   as  of  the    liLiht    rays   and   the 

•  at. 

The  ei'fecl   i-  a  vasodilator  one  upon  the  -kin  and  a  reduction  in  li'en- 

•<urc,  which   i-  of  >ufhcient   duration  to  make  the  apjilica- 

tinii  valuable  in  many  cardiovascular  diseases,  including  angina  pect(jris. 

Tin-     I'jVct   of  an  electric  arc-liu'hl   bath  has  been  studied,  principally 

in  -elf.    by    lla.-.-elbach   of   the    Finsen    Institute  of  Copenhttli'en.1 

•  .  Abril.    r.MHi.  formulate^  the  i-e-ult-  of  tliese  observations  as 


_'.    Ti    -    ma}'   be   c;ru>ed   by   partial    paral\>is   of   tlie   muscular  walls 

•  i.     I  '  ••    -     wnes-    of    tlie    I';  spil'atrivy    moven  ents    is    tjff>et     by    then' 
i  h.   -o    that     the    amount     o!  per    minute    is 

the 


-  i!,c:''-a-i  ICIM  1  in  o;  :H  !'-. 

ilat  ion. 

much  moi'e  i  i  e-  at  2 1  inchi's 

! ront  and  1  >ack  < >\' 

"iik  '       •    . '         •     con-i  it  u'  ioiial    -ympt<  im-, 

.    '  ormal   t  en  i  pi  i  a- 
'   on.  a  HOP 


PHOTOTHKKAl'Y 


Fi«.  4:U.— Straight 
filament  incandescent 
lamp  with  parabolic 
reflector  for  concen- 
trated electric  -  liulit 
bath-  f \Vulffs  patent. 
Reini-rer,  Gilbert  A: 
Scliall,  Elaugen). 


The    Physiologic    Effect   of   Incandescent    Electric-light    Baths.— 

The  most  marked  effects  are  profuse  sweating  and  superficial  va-odila- 
talion  which  increased  tissue  changes  and  lowered 
arterial  pension.     As  commonly  applied  the  effect  is 
due  chiefly  to  the  radiant   heat,  but   there  is  suffi- 
cient evidence  that  the  light  itself  is  a'so  beneficial. 

The  Temperature  of  Incandescent  Electric-light 
Buthx. — The  statement  is  sometimes  made  that 
elect ric-light  baths  at  about  the  temperature  of  the 
body  will  cause  profuse  perspiration  in  five  or  ten 
minutes.  Experiments  by  Pariset1  with  different 
kinds  of  thermometers  show  that  thermometers  ex- 
posed to  radiant  heat  in  the  open  air  register  very 
differently  (a  difference  of  31°  ('.),  according  to 
whether  the  mercury  bulb  is  a  dull  black  or  is  of 
the  usual  polished  glass.  Even  after  fifteen  minutes 
in  a  closed  electric-light  bath  the  two  thermometers 
showed  a  difference  of  9°  ('.  (about  17°  F.).  It  is 
essential  that  the  temperature  the  patient  is  exposed 
TO  should  be  known  and  that  the  thermometer  bulb 
should  be  blackened  and  should  be  exposed  to  the 
direct  rays  of  the  light  at  the  same  distance  as  the  patient.  Sweating 
may  be  produced  by  dark  heat,  but  it  requires  a  higher  temperature  and 
lacks  the  other  effects  produced  by  the  penetration  of  radiant  heat  from 
a  luminous  source.  It  is  not  always  necessary  or  desirable  to  have  the 
electric-light  bath  closed  up  practically  air-tight.  It  is  sometimes  pleas- 
anter  to  the  patient  to  have  the  light  bath  ventilated  so  that  the  patient 
is  not  in  as  hot  an  air  bath  as  in  the  other  case.  To  make  this  equally 
effective  the  light  should  be  concentrated  upon  the  patient  and  not 
wasted  in  heating  the  walls  of  the  cabinet  and  the  air  contained  therein. 
An  incandescent  lamp  with  a  long  straight  filament  placed  along  the 
focus  of  a  parabolic  mirror  (Fig.  431)  yields  parallel,  not  divergent,  rays, 
which  are  directed  toward  the  nearest  surface  of  the  body.  All  the 
light  from  a  sufficient  number  of  such  lamps  distributed  uniformly  over 
the  surface  of  the  body  will  produce  the  effects  of  light  and  radiant 
heat  without  the  disagreeable  effects  of  a  hot-air  bath. 

The  temperature  of  the  air  in  the  ordinary  closed  electric-light  bath- 
cabinet  is  about  SO0  ('.  or  177°  F. 

The  concentrated  electric-light  bath  with  ventilation  causes  perspira- 
tion to  begin  at  a  temperature  of  77°  F.,  and  the  maximum  temperature 
of  the  air  need  not  be  over  112°  F.  A  thermometer  with  a  blackened 
bulb  placed  at  the  surfac0  of  the  body  and  directly  exposed  to  the  ravs 


Hill 


higher   temperature. 


probably  about  177°  V. 

Treatment     by     Concentrated     Incandescent     Electric     Light. 

Five  hundred  candle-power  applied  locally  for  about  fifteen  minutes 
is  verv  effective  in  sciatica,  lumbago,  dyspepsia,  colitis,  pruritus  vulva1, 
rheumatoid  arthritis,  and  cases  upon  the  border-line  between  gout  and 
neuriti^.  Sonic  of  the  latter  have  finger-joints  which  are  red  and  shiny 
and  >\vollen  and  exquisitely  lender.  The  application  should  be  Mrouu: 
enouuli  to  redden  the  skin  and  cause  the  patient  to  move  about  to 
prevent  overheating,  but  not  strop  L:  enough  to  bli>ter.  Static  elec- 
tricity is  a  valuable  adjunct  in  the  treatment  of  these  conditions. 
lt'.  H.  ilo  la  Stic.  <!••  Uiol..  Julv  3.  l'.)<)7. 


tiSt)  MEDICAL    ELECTRICITY    AND    RONTOEX    RAYS 

Radiant  light  and  heat  induce  hyperemia  and  increase  the  number 
and  activity  of  the  phagocytes  and  in  this  way  they  are  valuable  for 
local  infections.  Before  suppuration  they  may  prevent  it  or  may 
hasten  it  if  it  is  inevitable,  and  after  suppuration  they  may  hasten  res- 
olution. 

In  the  treatment  of  war  wounds,  radiant  light  and  heat  applied  for 
one  or  two  or  more  hours  a  day  promote  healing,  and  tend  to  prevent 
fibrous  cicat  rices.1 

Infected,  sloughing,  and  sluggish  wounds  are  successfully  treated 
by  ordinary  incandescent  light  applied  over  a  dressing  wet  with  boric- 
acid  solution  and  covered  with  rubber  cloth,  and  good  results  are  ob- 
tained after  laparotomy  for  appendical  abscess,  perforated  gall-bladder; 
also  in  tuberculous  and  gonorrheal  joint  infections,  carbuncles  and 
furuncles,  .r-ray  burns,  and  frozen  extremities.  Infected  war  wounds, 
(  ieorge  \\".  ('rile  says,  do  better  in  this  than  any  other  way.- 

R.  Tait  McKen/ie:i  has  found  that  radiant  heat  and  massage  will 
almost  always  soften  and  loosen  up  cicatrices  of  war  wounds. 

Philip  Jordan'  reports  ;•>  cases  of  apparent  mastoiditis  cured 
by  radiant  light  and  heat. 

A  few  treatments  by  incandescent  light  removed  the  symptoms  of 
pseudo-angina  of  his  own  heart  ((!.  Betton  Masscy). 

Treatment  by  Red  Light. — This  is  effective  in  smallpox,  where 
it  prevents  pitting,  and  in  scarlet  fever,  measles,  erysipelas,  and  noma. 
It  is  ordinarily  applied  by  keeping  the  patient  in  a  room  where  only 
red  light  is  admitted.  There  seems  to  be  reason  to  think  that  the 
.-ame  results  would  not  be  obtained  in  complete  darkness,  that  they  are 
not  due  alone  to  the  exclusion  of  the  other  colors,  but  that  the  red  light 
has  a  specific  effect  upon  the  skin  and  renders  n  resistant  to  bacterial 
and  other  morbific  agents. 

The  cure  of  recurrent  sunburn  by  wearing  a  red  veil/1  and  of  ec/.ema 
by  sunlight,  while  the  affected  parts  are  covered  by  red  cloth,  are 
along  the  same  lines,  freckles,  seborrheic  ec/.ema.  and  rosacea  seborr- 
hu-ica  have  been  treated  by  ointments  containing  a  red  pigment  ( I'nna). 

Blue-light  Anesthesia.  The  claim  is  made  that  blue  light  exerts 
a  calmative  and  sedative  influence  and  produces  a  sense  ot  well-being, 
and  that  fixation  of  the  eyes  upon  this  light  for  a  few  seconds  produces 
insensibility  of  the  face.  This  is  said  to  permit  of  the  painless  perform- 
ance of  minor  operat  ions,  part  icularly  the  extract  ion  of  teet  h. 

The    patient's    face    is    covered    with    a    ll^llt    blue    veil;    and    there    IS 
a    Hi-candle-power  incandescent  electric-light   In 
distance  of  aliout    7  inches.      The  patient    looks 
or  t  h 
coin  lit  i<  in 

t  \v<  i-t  hir 
t  hin 


and  at  the  end  of  that   time  i.-  usually  t'< 


PHOTOTIIKHAPY  ()S7 

Blue-light  Treatment. — Blue  spectacles  have  long  been  used  for  the 
protection  of  normal  eyes  from  the  excessive  sunlight  at  the  sear-bore 
and  for  the  protection  at  all  times  of  eyes  rendered  sensitive  by  some 
disease.  Smoked  glasses  seem  to  do  equally  well  and  it  seem.-  pr<  ibuble 
that  the  effect  is  due  to  the  obstruction  of  a  large  proportion  of  the 
light,  including  practically  all  the  ultraviolet  rays  rather  than  to  the 
particular  color  of  the  glass. 

The  effect  of  blue  glass  windows  upon  the  growth  of  plants  and 
the  health  of  persons  in  rooms  thus  illuminated  were  studied  some  year* 
ago,  but  the  method  lias  been  abandoned. 

The  Minin  Lamp. — This  is  an  incandescent  lam])  with  a  blue  glass 
bulb  and  a  reflector.  Its  effect  is  almost  exclusively  due  to  heat  and  is 
favorable  in  joint  injuries  and  inflammations,  and  in  eczema,  superficial 
dermatoses,  neuralgia,  and  rheumatism. 

Kaiser's  method  of  blue-light  (Ji<  ra/n/1  employs  a  carbon  arc  lamp 
actuated  by  a  direct  current  of  15  amperes  and  110  volts,  with  a  para- 
bolic reflector  and  a  screen  of  strips  of  blue  glass  or  a  screen  made  of  a 
glass-walled  cell  full  of  water  in  which  methylenc-blue  and  a  little  alum 
are  dissolved.  The  latter  makes  the  best  screen  because  it  arrests 
most  of  the  heat  rays.  The  patient  is  at  the  focus  of  the  rays  about 
2  meters  ((>  feet)  from  the  lamp,  (lood  results  are  reported  in  tuber- 
culosis of  the  joints  and  of  the  skin  (lupus). 

Itlnc-lit/ht  iritfi  moderate  Jietit  has  been  used  by  the  author  in  the 
treatment  of  pain  and  swelling  of  the  face  from  irritation  of  the  nerve 
leading  to  a  tooth.  Such  a  condition  may  occur  after  a  crown  is  applied, 
and  if  it  is  simply  from  mechanic  and  chemic  irritation  without  infec- 
tion the  author  has  seen  it  subside  under  this  treatment.  The  lamp 
employed  was  a  32-candle-power  incandescent  blue  glass  bulb  with  a 
parabolic  reflector.  The  face  was  protected  by  cardboard  with  a  hole 
o  inches  in  diameter  which  exposed  the  swollen  cheek.  The  rays  were 
not  brought  to  a  sharp  focus,  but  concentrated  upon  the  area,  and 
the  heat  was  entirely  endurable,  but  still  sufficient  to  redden  the  skin. 
Only  one  application  was  made,  lasting  ten  minutes.  The  case  did 
not  progress  beyond  the  stage  at  which  the  light  treatment  was  applied, 
and  in  a  short  time  the  irritation  subsided  without  having  to  remove 
the  gold  crown.  How  much  the  light  treatment  had  to  do  with 
securing  this  result  is  a  matter  which  the  dentist  (Dr.  Gillett)  is  unable 
to  decide.  The  patient  herself  did  not  think  the  light  had  produced 
much  effect. 

Ill a< -lit/lit  Butli*. — ( leneral  baths  of  blue  liirht  at  a  temperature  of 
from  lot0  to  122°  F.  and  lasting  for  twenty  or  twenty-five  minutes 
may  be  given  every  day  at  first  and  later  every  two  or  three  days  and 
each  light  bath  may  be  followed  by  a  hath  in  tepid  water.  They  have 
a  sedative  and  analgesic  effect  in  such  cases  as  neuralgia  and  rheuma- 
tism. 

Local  baths  of  blue  light  in  the  open  air.  not  a  cabinet,  have  been 
found  very  effective  in  different  cases  of  neuralgia.  Albert -\Yeil'-'  re- 
ports the  cure  of  a  case  of  severe  intercostal  neuralgia  of  two  months' 
duration  by  fifteen  treatments  lasting  ten  minute-  each:  and  in  a  ease 
of  sciatica,  in  which  other  means  had  failed.  Mue-liu'lit  baths  effected  a 
cure  in  fifteen  days.  The  apparatus  required  is  a  -^-candle-power  blue 
glas-  incandescent  lamp  with  a  large  parabolic  reflector. 

No.  4. 

!.">,   190."). 


MKDH  AL    i:i.]:(  THK  ITV    AND    KON'TOKX    HAYS 

EXAMPLES  OF  THE  THERAPEUTIC  USE  OF  ELECTRIC  ARC  LIGHT 

I'ltraviolet  liii'ht  has  been  used  in  the  t  real  nit-nt  of  ulceration  of  the 
cornea  ami  of  conjunctivitis,  and  in  treating  .r-ray  dermatitis. 

Tin  ritmri.tli  t  l\u  /  in  Lnconiotnr  Ata.rin.  Liebermann  has  reported 
beneficial  effects  from  the  ulti'aviolet  ray  applied  alternately  to  the 
cervical,  lumbar,  ami  the  sacral  regions.  Improvement  took  place  in 
1  he  pain  am  1  1  he  coon  liliat  n  m. 

It*  f*.s<  ///  /.<//»>/*.— This  is  extremely  important  ami  is  described 
on  pa<:e  (122. 

Elii'tric-lii/ltt  htitlix  with  either  incandescent  or  arc  lamps  are  among 
the  best  means  of  treating  rheumatism  and  gout  and  a  variety  of  cardio- 
vascular affect  ions. 

Ani/inn  I'trla/'ifi.-  Fifteen  patients  treated  by  .Tacobaous*  showed 
the  h  'Mowing  results:  1  very  grave  cases  showed  some  improvement, 
but  latiT  succumbed  to  the  progress  of  the  disease;  :•>  old  severe  cases 
were  improved  and  the  severity  of  the  attacks  was  reduced;  in  o  milder 
cases  the  attack.-  of  precordial  pain  disappeared  entirely,  and  this  was 
tin-  case  also  in  •!  moderately  severe  cases.  That  the  effect  was  due 
to  the  treatment  is  shown  by  the  recurrence  of  pain  in  '2  cases  when 
the  treatment  was  stopped  and  its  disappearance  when  the  treatment 
was  resumed. 

Ila--elbach  and  .Tacobaeus2  have  pursued  the  same  line  of  treatment 
somewhat  further.  They  use  powerful  carbon  arc  lamps  in  the  baths 
and  obtain  a  dermatitis  which  from  repeated  applications  becomes 
a  chronic  hyperemia  lasting  perhaps  as  long  as  a  year  and  ma}'  be  accom- 
panied by  a  la-ling  effect  in  relieving  internal  congestion  and  the  like. 
Respiration  exchanges  are  unaltered,  but  respirations  become  less  fre- 
quent  and  deeper,  inspiration  being  prolonged.  A  patient  with  cardiac 
distress  breathes  much  more  freely.  Arterial  pressure  begins  to  dimin- 
ish after  the  third  treatment.  Both  the  diastolic  and  the  systolic 
pressures  are  reduced,  but  the  difference  between  the  two  becomes 
greater  than  before.  The  pulse-rate  is  unaffected.  Dilatation  of  the 
'  is  iisiiallv  reduced  during  a  course  of  treatment. 

Fifty   ca.-es   of   various  neuroses   treated   in    this  way  showed   great 

'   lent . 

'  hie  hundred  and  thirty-one  patients  with  chrome  or  organic  heart- 

ii-easi     \\ere    treated.      In    some    case-    the    valvular   insufficiency    was 

ed.    but    even    then    the   sense   of   fulness   and   tension   was 

•    hi'-ed      nd  so   ,vere  the  dyspnea  and  pal  pit  at  ion  on  exertion.      Cardiac 

-   M-nalh    reduced;    !  !    cases  of  true  angina    pectoi'is  ga\'e 

.'.::i\    fa\'orab!e  results  \\iiich  were  (piite  lasting. 

Combined    Electric  light    Baths    and    Hydro-electric    Baths    in 

Obesity.      The  elect  ric-liu'ht   bath  is  followed  by  a  general  warm  water 

.  •  •  --P.  ei\    cooled,  whili    a  '    '  e  i  ime  a  sinusoidal 

i       '  '          '. ' |(  i   'o    I  _'( i   ma.    i-  ajiplied   through   it    for  twentv   to  thirty 

'       of  I  In     im  i-1    effect  ive   modes   '  if   t  :vat  incut.       I'att}' 

•    heart   i-  a  cont  ra-indicat  ion  to  this  treatment. 

Example-  of  the  Use  of  the   Mercury  Vapor  Lamp.-   The  author 

•'  •    Cooper  llev.i't    lamp  with  benefit    in  a   case  of  laryn- 

i  uberculosis.      A    lamji    of     l.'n    candle-jiowei'.    to 

i-  added  the  influence  of  a   reilectoi'  back  of  it.  is  placed  horizon- 

bare  che-1    at    a   di-taiice  of  ,"   or  li  inches  from   the 


TOTHF.KArY 


skm.  An  exposure  of  ten  minutes  reddens  the  skin  temporarily.  The 
treatment  was  combined  \vith  the  use  of  the  ./'-ray  and  high-frequency 
currents  and  resulted  in  the  healing  of  the  ulcerated  vocal  cord.-  and  a 
marked  increase  in  weight,  appetite,  and  strength.  I-'inaiicial  diflicitl- 
1  ies  then  caused  the  patient  to  discontinue  the  treatment  and  she  died 
of  pulmonary  tuberculosis  about  a  year  later. 

Xogier  and  Thevenot  have  shown  bv  1  heir  experiments1  that  applied 
111  this  way  the  light  from  the  Cooper  He\vitt  lamp  does  not  kill  or  ap- 
parently  influence  bacteria  with  an  exposure  of  seventy-five  minutes. 
But  in  a  more  highly  concentrated  form  the  mercury  vapor  light  lias  a 
bactericidal  effect  and  may  be  used  in  the  treatment  of  lupus  ( Kromayer) , 

As  an  electric-light  bath  the  light  from  the  Cooper  Hewitt  mercury 
vapor  lamp  produces  a  general  tonic  effect,  improving  the  appetite  and 
digestion  and  removing  insomnia.  .Voider  has  seen  long-standing  cases 
of  amenorrhea  become  normal  under  the  treatment.  He  obtained  satis- 
factory results  in  cases  of  anemia  and  chlorosis  by  combining  this  treat- 
ment with  general  measures. 

Locally,  it  has  the  usual  analgesic  effect  of  radiant  heat  com- 
bined with  light,  and  relieves  gouty  and  rheumatic  and  muscular 
pains. 

Pelvic  pains  of  various  natures  are  often  relieved  by  applying  this 
or  similar  lights  over  the  hypogastrium. 

Xogier  has  shown  by  actual  dynamometric  measurement  in  12 
patienis  that  there  is  an  increase  in  muscular  power. 

Vttfuuin  Jlul/ix  of  I'ui'c  Qnnrtz. — These  can  be  made  up  to  about  2 
inches  in  diameter  by  fusing  quart/  .-and  with  scarcely  any  other  admix- 
ture. They  transmit  the  ultraviolet  ray  perfectly  and  mercury  vapor 
lamps  so  constructed  are  very  active  physiologically. 

The  uriol  lam])  is  practically  the  same  as  the  Cooper  Hewitt   lain]). 


hiii'h  rates  of  vibration  and  hence  more  of  the  ultraviolet  rays.  The 
effect  of  the  uviol  lamp  has  not  been  fully  tested,  but  it  has  been  found 
to  be  very  active  superficially,  and  Pelli/.ari  has  not  found  it  to  produce 
as  deep  an  effect  upon  lupus  as  the  Finsen  lamp. 

Dinijiiosfif  {' si  .•<  /if  tin  ('OOJHT  Hnn'tt  Lit/lit. — The  normal  face  pre- 
sents a  strikingly  unnatural  appearance  by  this  hirht  which  is  devoid 
of  red  rays.  Kvery  red  blood-vessel  looks  almost  black  and  the  lips 
are  a  dark  purple.  The  skiii  of  the  chest  and  abdomen  may  be  examined 
in  cases  of  suspected  syphilis  before  the  eruption:  the  latter  beinu' 
visible  bv  this  light  several  days  before  it  is  perceptible  by  ordinary 
liidit.  In  the  same  way  at  a  later  stage  the  eruption  may  be  found 
after  it  is  no  longer  noticeable  bv  ordinary  u^'lit.  The  Cooper  Hewitt 
mercury  vapor  lamp  may  also  be  used  to  watch  for  the  earliest  evidence 
of  Kontgen  dermatitis. 

Therapeutic  Uses  of  the  Kromayer  Lamp.— This  light  may  be 
applied  to  the  treatment  of  recent  trachoma. 

(  >ne  end  of  a  quart/  rod  is  in  clo-e  contact  wit  h  the  quartz  tube  of  the 
lamp,  and  all  the  liirht  passes  to  the  other  end  of  the  rod  and  affect-  the 
ti--ue-  without  any  lateral  diffusion.  Thi-  i-  a  successful  method  of 
t  reat  ment. 

With  the  lamp  at  a  distance  of  at  least  -1  inches  from  the  -kin.  an 
application  of  live  to  fifteen  minute-  i-  effective  in  a  wide  raime  of  -kin 
di<ease<.  Alopecia  areata.  alopecia  pityroides.  pityria-is  ro-ea.  super- 
ficial myco-e-.  pruritu-,  vitiliuo.  acne,  furuncle,  carbuncle,  lupus  ery- 

1  Si^oncl  C'onjiri-ss  of  Phy>iotli<T:ipy.  Home.  Oct.  \'.\.  l!»n7. 
it 


090 


MKDICAL    ELECTRICITY    AND    KONTCKN    HAYS 


themato-us,  folliculilis  decalvans  capitis,  folliculitis  barluv,  cutaneous 
tuberculosis,  ulcers  may  be  treated  in  this  way. 

\\ith  the  lamp  in  close  contact  and  the  tissue.-  blanched  by  com- 
pression or  by  adrenalin,  but  protected  from  excessive  heat  either  by  the 
water  circulating  in  the  lamp  itself  or  by  a  blue  screen  of  uviol  glass  to 
arrest  the  superficially  acting  chemic  rays,  the  effect  is  a  penetrating  one, 
and  the  longer  applications  should  only  be  made  after  considerable 
personal  experience  with  the  milder  ones.  The  dosage  for  lupus  vulgaris 
is  {ifteen  to  forty-five  minutes;  lupus  eryt  hcmatosus.  one  to  thirty 
minutes:  epithelioma,  thirty  to  sixty  minutes,  lupus  erythematosus.  one 
to  thirty  minutes;  epithelioma,  thirty  to  sixty  minute's:  nevus  vasculosus. 
thirty  to  sixty  minutes:  telangiectasis,  five  to  thirty  minutes;  acne  rosacea, 
live  to  thirty  minute.-:  ulcer.-,  live  to  thirty  minutes. 

A  quart/  mercury  vapor  lam]'),  suggested  by  Ihic/i  «n<l  Xayelschmidt,  is 
intended  for  aj)plication  at  a  distance  of  20  inches  or  so  for  a  reflex  effect 


-  Wall  Plug 


Ozone  Exit 


Rheostat 


Lamp  Connection 
1m.    \'.','2.      Miniature  alpino  .-un   dlanovia  ("'hcmiral   aii'l   Manufacturing  Co.,   Newark). 

upon  blood-pressure  and  for  the  treatment  of  a  long  ii-t  of  skin  diseases: 
lupus,  chancroid,  lipoma.  ne\'us.  alopecia  areata.  acne  vulgaris  and 
rosicea,  ec/ema.  frost-bite-,  intertrigo.  erythrasma,  chronic  ulcers, 
p-oriasis,  ec/ema  -el  mrrhoica,  falling  of  the  hair,  vitiligo.  The  dosage 
for  a  const  it  ut  ional  el  fed  is  t  hree  minute-  t  roiit  ami  back  at  a  distance  of 
2s  indie-  for  t  he  tir-t  treatment,  gradually'  increased  at  subsequent  t  reat- 
ment-  a-  the  -km  become-  tanned.  Finally,  the  exposures  may  be  as 
lony  as  twenty  minute-  at  a  di -lance  of  \~>  indie-.  The  dosage  in  ec/ema 
i-  one  minute  ,-it  1  il  indie-,  gradually  increased  at  subsequent  treatments 
to  ;i  maximum  i  >t  five  minute-  at  a  distance  of  .s  inches.  Acne,  ec/ema, 
and  other  di-ea-e-  of  the  face  ,-hould  receive  at  fir-t  one  minute  at  20 
indie-  Mini  gradually  increa>ed  to  a  maximum  of  three  minutes  at  the 
same  di-tancc.  ('In-mu:'  the  eyes  protect:-  them  -ufliciently. 

M  :i  M\'  uf  the  UK  he;  1 1  ii  in-  for  elect  ric-liiihl  t  real  men  t  in  medical  uyne- 
and  -1 : !  'j  II'M  i  ca-e-  are  met  hv  this  lamp. 

Examples  of  Ultraviolet  Ray  Therapy.  ( 'ora  Smith  Kirm  re|)ort>< 
cure  of  lupu-  eryt  heniatosiis,  tubercular  inland-  tor  \\-hidi  it  is  combined 
with  diathermy  through  the  neck  laterally;  chronic  acid  headaches 
with  vomit  niii ;  dccji  ero-ion  oi  cervix  u-ini:  t  lie  Kroma  ver  lamp  t  hroimh 
a  speculum  and  al-o  directly  to  cer\-|\  throu^li  applicator  on  a  long 
metal  tube,  ;d-o  . \lpiin  Sun  Lamp  to  \\liolc  trunk.  Shmule-  or  herpes 


1MIOTOTHKKAPY  (>(.)1 

zoster  were*  cureel  by  twenty  minutes  of  1000  watt  Ma/da  and  then  two 
minutes  of  Alpine  Sun  Lamp  at  24  inches.  Four  treatments  were  given 
in  a  week,  but  one  treatment  seemed  to  finish  the  disease;.  Herpes  o-f  the 
cheek  near  the  mouth  and  over  the  antrum  yielded  to  one  treatment  of 
one  minute  with  the  Kromayer  lamp  ?,  inch  from  lesion.  Acne  was 
cured  by  general  ravin"'  of  t  he  body  with  Alpine  Sun  Lamp  and  close  ray- 
in  g  of  lesions  with  Kromayer  lam])  twice  a  week,  also  colon  irrigations  for 
enormous  retention  stools,  in  a  case  previously  treated  by  an  expert 
with  £-ray.  Neurasthenia  was  Driven  three  treatments  weekly  Alpine 
Sun  gene'ral  raying  of  trunk,  at  first  two  minutes.  24  inches,  at  each  treat- 
ment one  minute  longer  and  one  inch  nearer,  until  fifteen  minutes  held 
there  preceded  by  hot  lamp  to  produce  hyperemia,  also  colon  irrigations. 
Bunion,  three  treatments  in  one  week,  Kromayer  lamp,  five,  ten,  and 
fifteen  minutes.  Pressure  neuritis  with  callus  at  base  of  little  toe,  one 
treatment  Kromayer  lamp,  2  inches,  five1  minute's,  another  ten  minutes 
thive  days  later.  He'inorrhoids  were1  treate'd  by  a  2-inch  quartz  appli- 
cator insertenl  into  rectum  and  pre>sseel  against  the  he-metrrhoidal  arch, 
treating  about  one-third  erf  the  circumfereone,  four  treatments,  all  to 
the1  same  area,  totaleel  thirteen  minutes,  burn  subsieled  in  ten  days. 
Insomnia,  with  mental  dulness  and  baldness.  Alpine1  lamp  15  inches  at 
first  five  minutes,  but  ineTcascd  three  minutes  eae'h  time  (every  three 
e>r  four  days)  to  keep  scalp  in  a  state  of  hype'ivmia,  alse>  gvneral  raying 
erf  trunk  two  minutes,  24  ine'hes,  increaseel  later.  Balelness,  case1  erf 
complete1  alopen-ia  oevurring  within  one  memth.  Eczema  erf  leg,  quartz 
window  of  Kromayer  lamp  presseel  against  skin  for  te*n  te>  sixty  minutes, 
total  ninety  minutes,  almost  to  stage  erf  blistering:  this  was  the  total  erf 
five  treatments  in  a  few  weeks,  Care-inemia  erf  breast,  lump  four  years' 
eluration,  no  ulceration,  but  some  enlargement  erf  the  axillary  glands, 
e-olon  irrigatiem,  Alpine  Sun  whe)le  trunk.  Kremiayer  lamp  in  contact 
with  the  bivast  over  the1  lump  anel  ?,  inch  te>  each  siele.  The  lump  was 
tivated  only  once  a  week  at  first,  five  minute's,  ine-reaseel  one  to  five1 
minutes  up  to  thirty-five*  minute's  a  sitting,  blistering  and  exudation 
three1  days  afteT  eae-h  treatment,  not  painful,  and  patie'iit  felt  they  we're 
doing  ge>e)d;  twenty  treatments  in  all. 

Donalel  McCaskey1  says  that  a  generalized  ejiiartz  light  sun  bath  erf 
8000  c.-p.  for  two  minute's  at  20  ine-hes  etver  the  entire1  nakenl  boely  as  a 
first  treatment  would  cause1  prostration,  chills,  and  fever,  anel  the  patient 
would  be1  unwilling  to  have  any  more  tivatnuMits. 

A  sample1  local  applicatiem  from  a  (jiiartz  mercury  vape>r  lamp  [it  a 
distance  <rf  10  ine'hes  from  the  skin  is  a  two-minute  treatment: 
distance  of  20  inche's,  te'n  minutes  once  a  wee'k.'2 

Heliotherapy  is  alse>  ivporteel  by  Campbell3  as  having  cuivd 
infee-tious  osteomyelitis  after  ivmoval  of  >eMjiie>tra  anel  war 
with  pus  and  -inuses  involving  boners,  joints,  or  ce'llular  tissue. 

Sunlight  in  the  Treatment  of  Tuberculosis.  A  host  of  observations 
show  that  exposure  of  the  part  to  the1  direct  rays  of  the'  sun  produe-es 
benefit  in  tuberculosis  of  the'  bones  and  joints.  Make  a  general  ex- 
posure for  three'  to  seven  hours  daily,  watching  the1  ef'lVct  upon  the 
hemoglobin  and  red  and  white  blood-cell-.  Campbell4  report-  the  cure 
of  an  apparently  hopeless  tuberculous  spine  and  hip-joint. 

1  Mc.l.  Rroonl,  October,  Hi.  l'.H7 

2  Jour.  Ainer.  Mr,l.  ASSOP.,  vol.  7'_>,  No.  !'_'.  March  22.  I'.U!). 

3  I, <><•.  cit  . 

4  Amrr.  .lour    Siir^..  ,lulv.   I'.il^. 


THE  A'-RAY 

Disn  iVKKKH  by  IIontLM'ti.  in  \\ur/buri:.  April  :>u.  IVi.').  the  .r-ray 
vvas  something  cm  irdy  new  and  not  foreshadowed  by  anything  else. 

I  Ibnt  _:••  -n  was  siudving  tin1  ("rookes  tube  and  the  cathode  rav  and 
had  the  tube  sn  thoroughly  covered  with  black  cardboard  that  no  visible 
!l;j.'ht  could  escape  into  tile  darkened  room.  lie  noticed,  none  the  less. 
thai  a  sheet  of  paper  coaled  with  tmmstale  of  calcium  be-all  to  emit 
liuht.  He  had  discovered  the  .r-ray.  a  form  of  radiation  which  will  pass 
'::•'';_,'!  substances  opaque  to  ordinary  light  and  produce  luminous 
effects  uj  ii  m  cert  all)  object  s  beyond. 

It  is  a  form  of  motion  similar  to  light,  tun  with  some  trillion.-  of 
vibrations  a  second  and  a  wave-length  a.-  shun,  sometimes,  a.-  ',  cm. 
It  penetrates  solid  bodies  opaque  to  lidit  waves  and  causes  brilliant 
fluorescence  in  certain  cheinic  substances  beyond. 

'The  /-ray  itself  i.-  invisible.  Our  perception  of  it  is  due1  to  the 
luminosity  of  fluorescent  substances  which  it  shines  upon. 

Differences  in  the  Penetrating  Power  of  Ordinary  Light  of 
Different  Colors.  —  F.ven  weak  blue  light  will  <j:t>  through  a  blue  solu-. 
lion  and  illuminate  objects  bevond.  while  the  strongest  blue  liu'ht  will 
be  -topped  by  a  solution  of  bichromate  of  pota.-h.  The  reverse  i.-  true 
of  yellow  li-'ht. 

Tlie  ruby  coloi-ed  ^lass  which  forms  the  window  of  a  photographic 
dark-room  transmits  the  red  rays  of  ordinary  linht  in  sufficient  abun- 
daiice  to  enable  one  to  see  object.-  distinctly,  but  if  a  blue  li.uiit  were 
user!  outside  of  the  dark-room  practically  none  of  it  would  penetrate' 
l!i'  ruby  n'lass  and  the  interior  of  the  dark-room  would  be  in  complete 
obscurity.  There  are  many  other  examples  of  substances  which  are 
t  r;  nsparent  to  ordinary  liulit  vibrations  of  a  certain  wave  length  and 

.    ,'•    io   others, 

Maiiv  lances  which   are   not    transparent,   still   ai'e   translucent. 

Th     -1  if  the  hand  i-  readily  -ecu  through  a  piece  of  porcelain  or  a 

-hee;    o!      ','hite    paper.       Neither   of    these    substances    would    serve    as    a 
for    a    sensitized    photographic    plate.     The    li^hi    goes    right 
A'ould  fo.i!  the  plate-.      1  \  \  a  i  •  k  pajier,  however,  absorbs 
lii    •       liiihl    and  serves  lo  protect  photographic  plates 
..'.'.      Transpai'eiic\-   io  ordinarx'   liLiht    is   like   color,  m 
ipon  the  arrangement  of  the  molecule-  of  the  substance 
mate   r  •  h e n  i  i c  or  atomic  composition.     Coal 
iamond.  con.-istiim  of  aliout   i-i|iially  pure  carbon. 
ireni    to  ordiiiar\'   li^ht.      A    transparent    solution   of 
•.  it  h  a  transparent  nil  will  form  an  opaque  emulsion. 
-    tittle  nr   no    part    in    n-^ard    lo    t  rans]  larency    1 1  < 
nd  1  ilack  i  ia|  iei  a  re  opai]  n  .  \'  hile  Lilass.  \\  hi'-h  is 
-   •  ra  n-i  ia  rent  . 

'lien    thai    certain    -ilbstatice-    which    are   opaque   to 
be  transparent    in    the  /-ray.   which   has  quite  a 

Difference    Between    the    x-Ray    and    Ordinary    Light.     The   ./-ray 

ter-     '     -•  vend   v  n  ordinar\    hull!    m   regard   io  it-  penetrating 


'!  UK    ./'-KAY 

power.      In  ilic  first  place  it  is  no!  influenced  by  molecular  arrangement , 

bill  probably  depends  entirely  upon  the  atomic  composition  of  ihe  sub- 
glance,  and  livnerailv,  the  jjrealer  the  specific  u'ravitv,  'he  more  opaque 
the  substance  is  to  the  .r-ray.  Hooks  ;md  aluniinuin  and  vulcanized 
hard  rubber  are  very  transparent.  (!lass  is  I  ransparenl .  but  le<s  so  if 
it  contain.-  lead.  The  human  hand,  \vater,  and  bisuiphate  of  carbon  are 
transparent.  ( 'opper.  silver,  lead.  <iold.  and  platinum  are  transparent 
if  not  in  too  thick  plates;  0.2  mm.  of  platinum  is  transparent.  All  these 
object-,  of  course,  are  opaque  to  ordinary  liu'ht.  Silver  and  copper  may 
be  decidedly  t  dicker :  !  .">  in  in.  of  lead  is  quite  opaque.  The  .-all  -  of  1  he 
different  metals  u'ive  very  similar  re-ult.-.  whether  solid  or  in  solution. 

Absorption  of  x-Rays  by  the  Air.  Air  ab-orbs  about  1  per  cent,  of  tho 
,r-ray  per  decimeter  H  inches).  Kveand  Day1  findtliat  rays  i'rom  a  very 
hard  .r-ra  v  tube  show  mi  absorpt  ion  of  a  I  tout  0.0002">  lor  each  cent  i  met  er 
of  air,  a  medium  tube  0.000  1.  and  a  very  soft  tube  I'rom  0.001  to  0.00  IN. 
These  figures  were  true  at  distances  of  from  (  to  10  meters.  The  rays 
reaching  beyond  I  he  latter  distance  showei  1  a  lessened  rate  of  absoiption. 

Tin'  opacity  i-  not  in  direct  relation  with  the  density  or  specific 
gravity  of  the  objects.  If  ii  were  so,  a  shee!  of  aluminum  l>  inches  square, 
and  thick  enough  to  be  as  opaque  as  a  sheet  of  platinum  t>  inches  -quare 
ouii'ht  to  have  the  same  weight.  This  is  \-ery  far  from  beinir  the  case. 
In  one  series  oi  experiment-  by  libntuen  sheets  of  platinum.  /me.  lead, 
and  aluminum  were  rolled  until  they  appeared  to  be  of  almost  equal 
transparency.  The  following  table  <rives  the  thickness  in  millimeters  of 
t  he  layer.-  relai  ive  to  I  he  plat  i num  and  their  density: 


In  this  experiment  a  sheet  of  alinniiin.ni  would  have  to  be  200  limes 
as  thick  as  a  sheet  of  platinum  in  order  to  have  the  same  opacity,  and 
a.-  its  density  i.-  about  one-eighth  that  of  platinum,  the  sheet  of  aluminum 
would  weiiih  twenty-five  times  as  much  as  one  of  platinum  equally 
opaque  to  thf  .r-rays. 

The  relation  between  density  and  opacitv  to  the  ./'-ray  varies  under 
different  condition-  of  the  .r-ray  tube.  When  the  tube  is  trivin1.:1  out 
mostly  hard  or  liiuhly  penetrating  rays  a  pieci  of  aluminum  I '2  mm. 
thiik  has  the  same  opacity  a.-  a  shed  of  silver  o.ll  mm.  thick: 
while  with  a  very  lo\\'  decree  of  vacuum  in  the  .r-ray  tube  1  mm.  oi 
aluminum  ha-  t  he  same  opacity  as  i  >.  1  1  mm.  of  silver.  Tin-  i-  the  ba-ic 
;  rinciple  of  the  Benoisi  radiochroniometer.  an  instrument  for  measur- 
i':_-  the  quality  of  the  ./--ray.  Color  has  no  influence  upon  transparency 
to  i  he  .r-ray.  and  neither  has  the  fact  that  the  substance  is  opaque  oi 
t  ransparenl  lo  ordinary  li^ht.  (llass  i-  much  less  transparent  to  ilu; 
.r-rav  than  black  paper,  wood,  or  aluminum. 

Lcntird'x  !.<n/'.  Different  substance-^  impinged  upon  by  .r-rays  of 
the  same  wave-length  ab-orb  them  e([uall\~  for  equal  weights.  7"A  ;x 

l'i    '(llililij   tint  x    >ni/   tl i/fii  ill'   In  In     : 

.r-Hays  are  not   perceptibly  refracied  by  Li'la--  ]>n-m-  or  b\-  water  or 
carbon  bi-ulphite.      1'owdei'eil  substances  are  quite  as  transparent  to  tlu^ 
1  I'lui.  Mai: .  -'•'>,  I'.iiL'.  r,s:;. 


MEDICAL    KLF.rTHiriTY     AM)     H()\T(iKN     HAYS 

x-ray  as  are  solid  ho  lies  of  equal  mass.  The  x-ray  cannot  be  concen- 
trated by  lenses.  No  appreciable  regular  reflection  occurs. 

Rood's  observations  in  regard  to  the  reflection  of  x-rays1  seemed  to 
indicate  that  ,,,',-,,,  of  the  x-ray  was  reflected  from  a  metallic  surface 
which  it  strikes  at  an  angle  of  4")  degrees.  In  the  light  of  our  present 
knowledge  it  seems  probable  that  this  small  fraction  of  x-ray  found  in  a 
region  which  it  seemingly  could  only  reach  by  reflection  gets  there  either 
by  secondary  radiation  or  hy  direct  penetration  through  the  interven- 
ing objects. 

Ordinary  light  may  he  made  up  of  a  mixture  of  different  colors,  but 
if  separated  by  a  prism  each  such  colored  beam  of  light  is  produced  by  a 
succession  of  uniform  waves. 

The  reflection  and  refraction  of  light  are  supposed  to  depend  upon 
this  property  of  regularity  of  vibration  which  is  lacking  in  x-rays  to  a 
very  great  extent.  A  stone  dropped  into  water  starts  a  wave  or  eleva- 
tion of  the  surface  of  the  water  which  forms  a  circle  of  constantly  increas- 
ing size,  and  if  this  were  only  followed  by  other  waves  when  other  pebbles 
of  various  sizes  were  thrown  into  the  water  with  different  speeds  the 
resulting  waves  would  be  analogous  to  those  of  the  x-ray.  Each  wave 
of  the  x-ray  requires  a  separate  and  distinct  impulse  and  may  have  a 
different  velocity  from  the  one  preceding  or  following  it. 

Another  reason  why  x-rays  are  not  ordinarily  reflected  is  that  the 
vibrations  are  so  much  smaller  than  those  of  light  that  an  ordinary  mir- 
ror is  as  coarse  to  them  as  the  surface  of  this  paper  is  to  ordinary  light, 
which  it  partly  transmits,  partly  absorbs,  and  partly  diffuses.  Diffusion 
in  the  case  of  the  x-ray  is  by  secondary  rays.  It  has  recently  been  ob- 
served that  the  x-ray  is  reflected  to  some  extent  from  the  cleavage  planes 
of  certain  crystals  which  are  smoother  than  most  Mirfaces  can  be  made 
art  ificially. 

The  x-ray  spectrum  is  measured  by  reflection  from  a  rocksalt 
crystal  toward  a  photographic  plate  or  an  utilization  chamber  which 
can  be  placed  at  different  angles  to  receive  and  measure  the  intensity 
of  different  wave  lengt  hs. 

Tip'  intensity  of  the  illumination  of  the  fluoroseopic  screen  varies 
inversely  with  the  square  of  the  distance.  The  x-ray  is  not  deflected  even 
1  iy  a  very  st  r<  >ng  magnet . 

Sir  George  Stokes'  Theory  of  the  Nature  of  the  x-Ray.-  The  rays 
are  due  io  a  succession  of  independent  pulsations  in  the  luminiferous 
ether  >?artmu  I  rom  the  points  ot  impact  ol  the  cathode  particles  upon 
the  ant  icat  hode.  These  are  not  con  t  unions  vibrations  like  t  hose  of  ordi- 
nary h^ht  ;  they  are  i-olated  and  extremely  short.  They  are  transverse 
like  I  ho-e  o|  huht  and  have  1  he  same  velocity .  According  to  Sir  Joseph 
'I  hom-on  Lord  Kelvin  ihese  pulsations  are  electromagnetic  waves. 

Corpuscular  Theory  of  the  x-Ray.  It  i-  believed  by  Bragg.  Porter, 
and  others  thai  the  ./'-ray  consists  of  material  particles  traveling  at  a 
very  '  iuh  rate  of  -peed.  Most  observers,  however,  believe  that  it  con- 
si-t-  oi  •.  •  :  lion-  of  i  he  iuminiferous  ether.  It  i-  interesting  to  note 
connection  that  ordinary  light  is  deviated  by  gravitation.  The 
h<_rhi  trmn  a  -tar  pa--mir  near  the  sun  deviates  about  O.s  second. 

PROPERTIES  OF  THE  RONTGEN  RAY 


THE    X-RAY  095 

causes  the  nil1  through  which  it  passes  to  become  a  conductor  of  elec- 
tricity, and  in  this  way  discharges  a  positively  or  negat  ively  charged  body. 
It  is  itself  invisible  and  does  not  produce  the  sensations  of  heat,  light,  or 
sound.  When  it  encounters  a  solid  substance  it  gives  rise  to  secondary 
x-rays  and  to  cathode  rays,  and  while  it  does  not  itself  carry  an  electric; 
charge,  one  is  secondarily  produced  in  bodies  exposed  to  it.  This  is  due 
to  the  ionization  of  the  air,  as  explained  later.  The  x-ray  is  not  subject 
to  ordinary  refraction  or  reflection. 

Polarization  of  ./'-Rays. — ('.  C.  Barkla  has  shown  that  primary  x-rays 
and  heterogenous  secondary  x-rays  are  partially  polarized  for  certain 
directions  of  propagation. 

Some  of  the  x-rays  from  the  anticathode  of  an  ordinary  x-ray  tube 
are  proved  to  be  polarized  by  an  experiment  which  shows  that  the 
secondary  rays  arising  from  the  impact  of  the  primary  rays  are  of  a 
different  quantity  and  quality,  according  to  whether  they  lie  in  the 
plane  of  the  cathode  stream  or  at  a  right  angle  to  it.  The  entirely 
polarized  rays  from  an  ordinary  x-ray  tube  have  the  property  of  gener- 
ating especially  rapid  cathode  rays.  The  non-polarized  part  differs 
only  in  degree  about  this.  An  aluminum  screen  increases  the  polariza- 
tion slightly. 

As  far  as  our  present  knowledge  goes  the  x-ray  travels  in  perfectly 
straight  lines,  but  on  striking  any  solid  substance  a  portion  of  the  rays 
is  absorbed,  another  portion  goes  straight  through,  and  a  third  por- 
tion, or  perhaps  an  effect  of  the  other  two,  causes  a  diffusion  of  x-rays  and 
cathode  rays  in  every  direction,  so  that  everything  in  the  x-ray  room  is 
affected  by  it.  The  only  way  to  prevent  a  photographic  plate  in  the 
x-ray  room  from  being  fogged,  for  instance,  is  to  keep  it  in  a  closed  box 
of  thick  metal.  The  x-ray  consists  of  many  different  wave-lengths  and 
these  have  different  degrees  of  penetration.  Different  substances 
present  more  or  less  resistance  to  the  passage  of  the  x-ray  and  this  ab- 
sorption is  very  closely  related  to  the  atomic  weight  of  the  substance. 
The  greater  the  atomic  weight  the  greater  the  resistance  to  the  passage 
of  the1  x-ray,  and  this  is  true  regardless  of  the  transparency  or  opacity 
of  the  substance  as  regards  ordinary  light.  Wood  is  very  transparent 
to  the  x-ray,  and  so  is  aluminum,  while  glass  is  much  less  transparent 
and  is  more  or  less  opaque  in  any  thickness  greater  than  -J,  inch.  The 
same  difference  in  the  amount  of  absorption  is  shown  by  the  different 
tissues  of  the  body.  The  lungs  are  almost  perfectly  transparent,  and  the 
.superficial  fascia  with  its  layer  of  fat.  the  muscles  and  solid  organs,  the 
bones  and  the  teeth  absorb  the  x-ray  to  a  greater  degree  in  the  order 
gi'ven.  The  different  degrees  of  absorption  cause  the  x-ray  which  has 
passed  through  any  part  of  the  body  to  produce  a  visible  image  upon  a 
fluorescent  screen  or  a  photographic  plate.  \\  e  shall  see  further  on 
that  an  x-ray  picture  is  a  chart  of  densities  of  the  different  tissues  trav- 
ersed, and  that  next  to  safety  the  desiderata  in  radiography  and 
fluoroscopy  are  great  intensity  of  radiance  and  a  quality  of  x-ray,  which 
shows  the  greatest  difference  in  the  decree  of  absorption  in  passing 
through  different  tissues. 

\'t  /•//  suft  X-/Y///X  are  produced  by  an  x-ray  tube  which  is  so  constructed 
as  to  be  excited  by  a  potential  of  only  '.'Oil  volts.  W.  Sent/1  finds  that 
different  gases  absorb  these  rays  in  different  proportions,  but  not  in  any 
direct  proportion  to  their  atomic  weight.  For  instance,  for  rays  pro- 
duced by  1400  volts  oxygen  is  very  opaque  and  vapor  of  sulphur  very 
transparent. 

1  Phvs.  Zcit.,  i:',.  lUl'J.   I7t>. 


b!»t)  MKD1CA1.    Kl.Kc   IKHri'Y    AND    RONTGEN     HAYS 

The  secondary  rays  ari-ing  when  t  he  .r-ray  st  rikes  any  solid  object,  or 
even  when  it  pa.-.-e-  i  h  rough  tin-  air,  show  evidences  of  being  polari/able. 
llaga:  find-  that  under  appropriate  condition-  the  secondary  rays  are 
five  time-  a-  -t  roiig  in  one  plane  as  in  another  at  right  angle.-  to  it .  This 
tend-  to  the  conclusion  that  the  .r-ray  is  due  to  transverse  vibrations  in 
the  luminiferous  ether. 

Characteristic  Homogeneous  Rontgen  Rays.-  These  form  part  of 
the  .r-radiation  from  the  anticathode  of  a  ('rookes'  tube  and  have  a 
uniform  wave-length  which  is  dependent  upon  the  >pecific  gravity  of 
the  anti-cathode.  The  heavier  metals  produce  the  more  penetrating 
characteristic  Kr>ntgen  rays. 

Influence  of  Material  of  Anticathode  Upon  Character  of  Rontgen 
Rays.  Tin1  lo\\er  the  specific  gravity,  the  more  ab-orbable  are  the 
characteristic  homogeneous  .r-rays.  There  are  always  heterogeneous 
./•-ray-  in  add  it  ion  which  are  not  affected  by  t  he  nat  ure  of  t  he  anticathode 
except  as  to  quantity,  being  less  abundant  with  a  low  specific  gravity. 

Secondary  ./--Rays  and  Homogeneous  ./--Rays.— A  metal  impinged 
upon  by  .r-rays  gives  out  several  kinds  of  .r-rays:  Two  kinds  of  .r-rays, 
one  heterogeneous  of  the  same  wave-lengths  as  the  primary  .r-rays,  and 
one  homogeneous,  characteristic  ol  the  metal  impinged  upon  and  only 
excited  by  primary  .r-rays  of  more  rapid  vibration^:  also  there  are 
cathode  particle-. 

They  do  not  continue  to  be  emitted  for  even  ;,,',,,,  second  after  the 
expi  i-un '  cease-. 

The  characteristic  homogeneous  secondary  .r-rays  are  more  abun- 
dantlv  generated  by  impact  upon  substances  oi  high  atomic  weight  and 
are  independent  of  whether  it  is  a  pure  element  or  a  compound. 

,).  (  '.  (  'hapmaif  has  shown  that  the  same  characteristic  homogeneous 
secondary  .r-rays  are  produced  when  the  substance  is  m  ga>eous  form. 

The  impact  ot  homogeneous  .r-rays  produce's  homogeneous  and  hetero- 
geneoiis  -econdary  .r-rays,  and  al-o  secondary  cathodic  corpuscular  rays. 
\\  hen  .r-ra  vs  are  sufficient  ly  hard  to  produce  a  secom  lary  homogeneous 
characteri-t  ic  radiation  in  one  ot  the  element-  pre-ent  in  a  ga-.  there  is 
always  an  increase  in  the  emission  of  secondary  corpuscular  rays,  in  the 
ab-orbent  power  of  the  gas  for  the  ray-  in  que-tion  and  m  the  utilization 
product  d  by  i  hem  in  the  ga-.:  It  is  uncertain  \\helher  the  major  part 
oi  1 1  n  •  i  on  i /a  t  ion  o|  a  sias  is  produced  by  l  he  .r-rays  I  hem  selves  or  by  t  he 
secondary  cofpn-ciilar  rays.  Barkla  and  >imons'  conclude  from  their 
experiment  -  t  ha  t  it  i-  chiefly  due  to  t  he  .r-rays. 

Produc1":--,!!  of   Characteristic  ./--Rays.'     The  cathode   ((',  Kig.  I '.',:}> 

i-  plane.      The  cathode  mv-  are  about    parallel  and  pass  through  a  per- 

I oral  ion  ni  tli'-  anode  into  a  -pace  /,  where  t  hey  a  re  deviated  to  different 

I'jin  iic  held.      /  is  a   bra>s  cylinder  around  which  turn- 

it  la  1 1 -i        |  ,t  K. i   \\ire  carry  a  current  in  one  fixed  direct  ion.  producing 

;  <        aiitu  'ic   field   indicated  by  M    N.      The  voltage  is  varied  until  the 

\\  ill  excit  e  Us  cha  ract  en.-l  ic  rays,  reach  \  .  an  an  1 1- 

iterial    to   be   le.-ted.      Through    the   window    i  V\ ')   of 

-    practically   exclusively    the   characteristic   .r-rays.     .lie 

• ;  c  •  o!i  (m  -   i. '(iii! red  are  for: 


THK    X-RAY 


LM'.OO    volt: 

<),-_'()()     •• 
10,000     •• 


representing  velocities  of  the  cathode  particles  '2.X  x  1();|  cm.  per  second  for 
;diiininuin.  5.7(1  x  10'  for  iron,  ;md  (5.18  x  10'  for  copper. 

Characteristic  Absorption  of  Heterogeneous  ./'-Rays  by  Different 
Materials.— Charles  A.  Sadler  and  A.  -I.  Steven1  show  that  with  an 
aluminum  anticathode,  a  window  of  aluminum,  0.(HK>(>7  em. t  hick  arrests 
the  characteristic  homogeneous  x-rays  while  transmitting  the  hetero- 
geneous .r-rays  which  may  prove  to  have  a  certain  penetration.  Xow, 
increasing  the  thickness  of  the  aluminum  window,  they  find  that  the 
emergent  heterogeneous  rays  have  become  softer,  not  more  penetrating 
by  the  increased  thickness  of  the  aluminum.  I'sing  screens  of  different 


LT.    !•'>•'!. — Separation  of  .r-ray-  into  different  wave-lentiths  l>y  a  mairnet  ic  field,  M  to 


iiidarv  u'-ruvs  ai   the  accessory  anti- 


X.  and  production  ol  characteristic  homojreiieou 


ii  li.  ide,  V.      \\    i.-  an  aluininuiii  window  I  ivvond  \\  Inch  an  electroscope  detects  1  liese  ra\ 


materials  they  find  that  heterogeneous  rays  which  have  passed  through 
ii'oii  have  become  more  absorbable  or  softer  for  aluminum  than  the 
heterogeneous  rays  from  1  he  same  tube  without  tin-  interposition  of  the 
iron  screen. 

The  theory  is  that  substances  absorb  especially  the. r-rays.  which 
would  form  their  characteristic  homogeneous  radiation  if  they  were  used 
as  ant  ical  hodes. 

The  characteristic  x-rays  from  iron  are  highly  penetrating  to  alumi- 
num, and  if  these  are  especially  absorbed  the  average  penetration  to 
aluminum  is  reduced.  An  aluminum  screen  iiist'  increases  the  pene- 
tration to  an  iron  screen  beyond. 

This  does  not  mean  that  more  x-ray  u'et<  through  the  iron  screen 
1  han  if  the  aluminum  screen  were  not  t  here  also.  It  means  that  a  greater 
percentage  of  ray-  which  reach  the  iron  screen  get  through  it. 

Other  Ways  of  Photographing  Without  Light.  Electrophotography. 
-  An  ordinary  photographic  [date  wrapped  in  black  paper  is  laid  upon  a 
small  sh'vt  of  metal  about  the  same  si/e.  The  latter  is  connected  with 
the  negative  pole  of  a  small  spark  coi!  -  1  iii!'li  .  The  film  -ide  i-  upper- 
most and  a  coin  is  laid  on  top  of  the  envelope.  Over  the  coin  another 
sheet  of  metal  is  laid  which  is  connected  to  the  positive  terminal.  A 
single  spark  is  passed  across  the  spark-^ap.  I'pon  developing  the  plate 


698  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

a  perfect  image  of  the  coin  will  be  obtained.     Around  the  periphery  of 
the  coin  a  ring  or  bonier  of  minute  sparks  will  be  seen. 

Bi-ch'i'troijrnphx.—A  coin  is  placed  between  two  dry  plates  with  the 
same  result,  the  best  results  being  obtained  when  the  plates  are  bare-  in 
a  dark  room. 

MiiifiHtoyrnphn. — The  plate  is  wrapped  in  light  proof  paper  with  the 
coin  on  top,  laid  directly  on  the  film  side  of  the  plate.  A  piece  of  card- 
board i-  laid  upon  the  pole  terminals  of  a  powerful  horseshoe  or  electro- 
magnet ;  the  plate  facing  the  magnet  is  laid  upon  it.  The  armature 
i.-  then  gently  presented  to  the  glass  side  of  the  plate  and  allowed  to 
remain  as  attracted  by  the  magnet  for  a  few  minutes — five  to  ten. 
The  plate  is  developed  and  the  negative  obtained  will  show  a  shadow  of 
the  coin.  The  result  is  due  to  magnetism,  not  to  .r-ray. 

Tin  rmnijrn jihs. — The  plate  is  placed  in  water  for  a  very  short  time; 
the  coin  is  then  laid  upon  it  and  pressed  somewhat.  The  coin  is  to  have 
a  different  temperature,  either  hotter  or  colder  than  the  film.  Copper 
coins  should  be  used,  as  silver  will  not  give  the  effect.  The  developer  is 
then  poured  into  a  tray  with  the  coin  .-till  in  position.  The  coin  is  then 
removed  and  the  development  is  continued.  After  ten  or  sixteen  min- 
ute.-' development  or  even  half  an  hour,  we  find  an  image  of  the  coin 
there.  The  experiment  should  be  made  in  complete  darkness.  Even 
ruby  light  would  vitiate  the  result. 

lonization. — The  .r-ray  ionizes  a  gas  through  which  it  passes,  and 
therefore  causes  insulated  positively  or  negatively  charged  bodies  to 
lose  their  electric  charge.  Air  through  which  the  .r-ray  has  passed 
remains  ionized  for  some  time,  and  if  aspirated  through  a  tube  this 
ionized  air  will  discharge  an  electrified  body  which  has  itself  never  been 
exposed  to  the  .r-ray.  A  plug  of  cotton  wool  or  several  layers  of  very 
fine  wire  screen  will  remove  the  ionization  from  air  passed  through  it. 
Tossing  about  a  large  object,  whether  electrified  or  not.  in  ionized  air 
quickly  deprives  the  air  of  this  property.  It  is  gradually  lost  under  any 
circumst  ances. 

A'-rays  ionize  di-eleclric  liquids  as  well  as  gases. 

A  pencil  of  homogeneous  .r-rays  from  copper  or  silver  passes  through 
a  window  of  aluminum  into  the  interior  ot  a  cylmdric  condenser,  which 
metal  liive-  out  hardly  any  secondary  rays  under  the  influence  of  rays 
characteristic  of  copper  or  silver. 

\V.  Hratnr  ha-  made  certain  observations  upon  the  ;'-rays,  or  sec- 
ondary cathode  particles  excited  by  the  impact  of  .r-rays  upon  solid 
substances,  ;tnd  has  found  that  the  ionization  of  the  surrounding  gas  is 
no  more  than  would  be  accounted  for  by  these  secondary  cathode  rays. 
He  coii-ider.-  it  doubtful  whether  the  .r-ray  itself  ionizes  gases  directly. 

^•imill  inn*  are  -udi  as  are  produced  by  the  pas-age  of  the  .r-ray  or 
ot  t  he  hecquerel  ra  v-  1  h rough  t  he  air.  They  move  t  h rough  a  distance  ot 
about  1  cm.  /.' / /•'/»  iniiK,  ( lisc<  >vered  by  Langevili,  are  .">()  t  lines  more  num- 
eroii-  m  i  he  normal  at  mosphere.  but  t  heir  mobility  i-  about  '2000  1  hues  less. 

An  electrically  charged  body  with  a  solid  non-conductor  like  paraffin, 
i-  tran-parent   to  the  .r-ray,  interposed,  loses  it-  charge  when  ex- 
1 10 -i  i  i  iii  t  hi    ra  v,  1  iiit  t  his  doe-  not  take  place  if  1  here  is  a  complete  outer 
onnected  with  the  earth.      The  discharging  effect   is 
,-  mixed  air. 

iinot    be  concentrated   by   len-e-.      An  ./'-ray  picture  is 
t   -hadow,  hence  the  name  xlciu<ir<i/)!i. 
l'li\  -.  Zcit-clir.,  1'J.   I'.'l  I.   Msl. 


THK    T-HAY 


THE  PRODUCTION  OF  THE  *-RAY  IN  A  GAS -FILLED  TUBE 

A  glass  bulb  has  two  wires  entering  and  fused  into  it  and  is  ex- 
hausted to  the  proper  degree  of  vacuum,  about  1 1)(){)  ()()()  atmosphere, 
and  the  wires  are  made  the  positive  and  negative  terminals  of  an  elec- 
tric circuit.  When  a  current  of  very  high  potential  is  passed  through 
such  a  tube  a  stream  of  molecules  is  repelled  from  every  part  of  the  sur- 
face of  the  cathode  or  negative  terminal,  and  normally.  /.  e.,  perpendic- 


Fijj;.  -134. — Simple  form  of  x-ray  tube:  7",  Target  or  anticathode. 

ularly,  to  this  surface.  This  cathode  stream  on  striking  any  solid  sub- 
stance, like  the  glass  wall  of  the  tube,  gives  rise  to  the  form  of  motion 
called  the  .r-ray.  The  greatest  improvement  in  the  construction  of 
.r-ray  tubes  since  the  original  discovery  was  in  giving  the  cathode  a 
concave1  surface  and  focusing  the  cathode  stream  upon  a  disk  of  plati- 
num or  other  metal  with  a  high  melting-point,  called  the  target  or  ami- 
cathode.  This  causes  the  .r-ray  to  radiate  from  a  very  small  point  and 


Fig.  435 


permits  of  much  heavier  currents  being  used  than  was  possible  when 
the  cathode  stream  was  directed  against  the  more  easily  fused  glass 
wall  ot  thi'  tube.  There  has  consequently  been  a  wonderful  u'am  in 
intensity  and  clearness  of  definition. 

Directions  for  Successfully  Operating  an  x-Ray  Tube  Excited  by 
Either  a.  Static  Machine  or  an  x-Ray  Coil.  Before  proceeding  to  des- 
cribe the  methods  of  using  .r-ray  tubes,  it  is  first  essential  that  the 
operator  should  know  the  names  of  the  different  parts  of  a  tube.  Fig- 
ure 4i>4  illustrates  the  most  simple  form  of  .r-ray  tube  at  the  present 


1 00  Mini'  vi.   i.i.i.'  'i  !'i<  ITY   AND   HO.NTCKN   KAYS, 

time.  T  represents  tin-  target,  «r  anticathode,' which  may  bo  of  an> 
shape,  tun  which  \\ill  almoH  always  he  placed  neai'  the  center  ot  the 
h  ,'h.  and  at  an  anu.le  of  I."  decrees  to  the  iomr  axis  of  the  tube.  .1  is 
t  lie  external  connection  of  the  aiiticathodo;  11  i.-  tlie  external  connec- 
tion iif  the  al  ,  cup  or  cathode.  The  aluminum  cup  and  the 
taruvi  are  ciimm<>M  in  all  ordinary  ,r-ray  tnhes.  and  are  practically 
alwavs  placed  in  the  aho\'e-descrihed  portions. 


The  next  most  common  type  of  tube  i-  shown  by  I-'iir.  -1  ;•>.">.  As  you 
will  notice,  the  target  and  aluminum  cup  are  in  the  same  relative  posi- 
tion- as  in  !•  iu..  \:\\.  There  is.  however,  an  additional  connection  O, 
having  :i  flat  aluminum  di-k  in-ide  of  the  main  liulli.  Sometimes  it  is 
a  flat  di-k  as  -hown.  and  au'ain.  it  i-  -imply  a  suai^ht  aluminum  rod 
which  may  be  -harp-pointed.  In  a  recent  (iroene  and  Bauer  tube  the 
accessory  anode  consists  of  a  sheet-iron  cylinder  which  is  supposed  to 
certain  deleterious  <iases.  but  in  the  author'-  hand-  this  has  not 


diflerence.      Instead   of    placing    thi-   di-k    in    the 

i    I'i'j.    1:;.")    it    may  be  placed  a-  -hown  in   I'ii:.    K!ti.  ihc 

\-   thai    the  fiat    di-k   i-   placed   hack  of  the  target 

It    i-  -i  i  place.  |  a-  a   mat  tef  ol   ci  ill  veil  ieiice  ill  Ilia  II U- 

I'alile  in  ca-e  there  i-  any  inver-e  discharge. 

'uhr-,  illustrated  by    I-PJ.   i;;7,  i-  one  in    u'hicli    ihe 

lie   regulated.       I'   I'epre-en1~  a    -tmrt    piece  i  if 

Mili'mjr.  which  i-  <ealed  into  the.r-ray  tube  and 

red.      \\hen   the  palladium  or  platinum   tubing 


01 


is  heated  1o  a  bright  red,  it  allows  gas  to  pass  through  it   into  th 
tube,  and  in  this  manner  renders  the  inside  of  the  Imll)  a  belt 
ductor  than  before  heating.     The  particular  caution  in  u.-ing  tin 
of  regulator  is  to  pay  attention  to  t  he  color  of  t  he  metal.      Do  not 
to  a  white  heat  and  do  not  apply  the  heat  too  close  to  the  glass. 
metal  is  overheated,  the  tube  becomes  what  is  known  as  a  leak 
can  only  be  remedied  by  putting  in  a  new  regulator.      If  the  heat 
plied  too  close  to  the  idass  it  is  very  liable  to  crack  it. 


Figure  -loS  illustrates  a  self-regulating  tube.  When  a  spark  passes 
between  the  brass  pointer  7J  (patented  by  Queen  and  Company)  and  the 
negat  ive  connect  ion  />  it  causes  a  gas  to  be  liberated  from  1  he  mica  disks, 
and  in  this  manner  lowers  the  resistance  of  the  tube.  If  a  connection 
from  the  positive  pole  of  the  apparatus  is  made  to  the  terminal  I),  it 
causes  the  fine  metal  wire  which  is  wound  around  a  small  u'lass  rod  to 


c 


. 

Fiirure    l:!(.>    illustrates    another    type    of    self-rejjulatinj!    tube.      Thi 
acts  in  the  -ante  manner  as  the  one  above  described,  excepting  that    it 
does  not   have  any  device  for  increasing  the  resistance  of  the  tube. 

A   u'reat    manv   tube-  are  bein^'  put    on   the 


702 


MKDICAI.     KI.KCTHICITY    AM)    KOVH.KN     KAYS 


apparatus,  ami  the  aluminum  cup  •with  tin-  negative  pole  of  your  ap- 
paratus, you  are  certain  to  have  it    connected  properly,  and   whatever 


NO8. 


NO  11 


N04 


/htciiin<i   device    mi    regulator    or 


anode   surface:    2,    cathode 
1    cap    of    anti- 
cap  of  anode 
rv  aiiticathode 
on  regulator 
main    hull)    ti 


other  connect  ions  may  he  on   the  tube  are   usually   for  regulating  its 
resistance  in  some  manner. 

Figure  440  depict-  the  different  parts  of  a  gas-filled  .r-ray  tube. 

Production  of  the  x-Ray  in  an  Electron  Discharge  Tube,  for  Exam- 


pie, the  Coolidge  Tube.     Such  ;i  tube  i-  exhau-ted  to  ,-i  prad  ically  per- 

cuum  -A    ic!i  will  not  permit  the  passage-  of  even  100.00(1  volts  be- 

.  inch  apart.      The   cnthode  consists  of  ;i  tungsten 


TIIK  r-K 


spiral  which  when  rendered  incandescent  by  ;i  current  of  about  4 
amperes  and  12  volts  liberates  electrons.  These  under  the  influence  of  a 
high  voltage  form  the  cathode  stream  and  by  their  impact  upon  the; 
anticathode,  originally  a  solid  mass  of  tungsten,  generate  .r-rays.  In- 
creasing the  strength  of  the  low  tension  current  sent  through  the  fila- 
ment increases  its  incandescence  and  the  numbers  of  electrons  liberated. 
This  has  the  same  effect  as  lowering  the  degree  of  vacuum  in  a  gas- 
filled  tube.  The  (  'oolidge  tube  is  very  largely  used  at  the  present 
writing  (1!)19).  (See  also  page  774.) 

The  first  thing  to  know  about  a  tube  is  to  have  a  clear  understanding 
as  to  what  is  meant  by  a  soft  or  low  tube,  a  medium  and  a  high  or  hard 
tube,  and  in  connection  with  this  Fig.  441  shows  an  rr-ray  tube  con- 
nected directlv  to  the  sliding  rods  of  a  static-  machine  or  the  secondary 


l-'ij:.  44J. — Spark-sap 

terminals  of  an  .r-ray  coil.  Assume  that  it  is  connected  with  the  ter- 
minals of  a  static  machine  whose  discharging  rods  1  and  2  are  in  con- 
tact, then  upon  slowly  separating  them  a  spark  will  appear  which  ceases 
when  they  are  separated  I  inch,  and  the  tube  lights  up.  This  would  be 
termed  a  soft  or  low  tube,  having  a  parallel  spark-gap  of  .',  inch.  By 
the  parallel  spark-gap  is  meant  that  having  a  tube  connected  as  per 
illustration,  and  1  and  2  in  contact,  then  the  distance  which  it  is  neces- 
sary to  separate  them  to  stop  the  spark  from  passim:  between  them  i.- 


known  as  the  parallel  spark-gap.      A  parallel  spark  from    I   inch  to   11 
inches  on  the  static  machine  would  mean  a  medium  tube;  from   11   to 


21  inches,  a  high  tube,  and  a  tube  should  nol  be  used  having  a  parallel 
spark-gap  of  more  than    1   inches  on  the  Matte  machine.      (  )n  a  coil  a 


parallel  spark-gap  of  :>  inche 


nves  about   the  same  ray  as  the    ',-inch 
machine.      A   ">-inch  parallel  spark-nap 

ui  the  static  machine,  and  an  s-inch 

parallel  spark-gap  on  the  coil  the  same  as  t  he  :}-ii  id  i  on  the  static.  A  t  ube 
that  has  a  parallel  spark-gap  of  '.»  inche-.  should  have  the  adjlistor  so 
i-t  stops  the  spark  from  appearing  bet  ween  the  terminals  of  the 


(Ill  MK1MCAL     Kl.Kt  TKHTIY    AND    KONTCKN     HAYS 

mil.  Wlicn  a  tulu'  has  a  parallel  spark-gap  of  le-s  than  \  inch  on  a 
static  machine,  then  hy  means  of  what  is  known  as  a  wicx  spark-yci])  or 
Uiilit-nijuhttor,  a-  -hown  in  Kin.  111.  a  very  much  I  letter  ray  can  he  oh- 
tained  from  the  tuhe  hy  separating  o  and  -1,  so  that  a  spark  appears  he- 
tween  them.  If  the  tuhe  is  very  low.  having  a  parallel  spark-gap  ahout  J, 
inch,  then  it  mav  he  necessary  to  separate*  •>  and  1  on  each  side  from  1 


to  2  inches.  AYhen  this  is  the  case,  a  multiple  -park-gap,  as  shown 
in  Fi«r.  11.").  gives  a  more  steady  ray.  This  is  due  to  the  fact  that  the 
row  of  hrass  halls  keeps  the  spark  in  line,  and  it  doe-  not  tend  to  fly 
oft.  as  when  a  single  spark-gap  of  the  same  total  length  and  resistance 
is  used.  The  action  of  the  series  spark-gap  in  conned  ion  with  the  static 
machine  is  to  allow  it  to  generate  more  current.  A  static  machine  on 


ry    low    resi-tance.    -uch    as    i-    the    e;ise    when    all 
parallel  .-park-nap  of   1   indi  i-  used,  \\ill  genera te  a 
amount    ot    current,    whereas,    when    a    resistance 
e  rurcmt.   it   uenerate-  more  current,  and,  in  fact. 
:  rod  need  in  the  curciiit ,  the  more  current  the  ma- 
1   i"   i'-   capacity.      A-ide   iVom    the  -hurt    parallel 
il-aiion    that    a    tulie   is   lo\v    or  -oft    i-   the  appear- 


THE    .f-UAY 


anco  of  a  blue  stream  hot  ween  the  target  and  the  aluminum  cup  (Fig. 
441)-  The  majority  of  the  .r-rays  are  generated  on  the  target  at  the 
point  at  which  this  blue  stream  strikes,  and  this  blue  stream  is  called 
the  cathode  stream.  Prof.  S.  P.  Thompson  has  demonstrated  the  fact, 
that  the  .r-rays  are  given  off  in  equal  numbers  in  all  directions  from  the 
anterior  surface  of  the  target ,  and  not  a  maximum  number  at  right  angles 
to  the  (-(Miter  of  the  target.  Caution:  When  a  tube  is  to  be  used  do  not 
separate1  the  secondary  terminals  of  the  apparatus  more  than  1  inch 
beyond  the  parallel  spark-gap  of  the  tube;  and  if  it  is  used  on  a  static 
machine,  and  has  a  parallel  spark-gap  of  more  than  '•*>  inches,  then  use 
the  regulator  just  sufficiently  to  obtain  a  3-inch  parallel  spark-gap, 
and  if  on  a  coil,  an  S-  or  9-inch  parallel  spark-gap  at  the  most.  The 
.shorter  the  parallel  spark,  the  less  will  be  the  penetrating  quality  of  the 
rays. 

When  a  tube  of  the  type  shown  in  Fig.  444  is  connected  as  follows: 
C  to  the  positive  terminal,  H  to  the  negative  terminal,  then  if  this 
is  a  incdinni  tube,  those  connections  will  give  the  least  parallel  spark- 
gap  of  this  particular  tube.  If  the  positive  connection  is  made  on  the 
terminal  .1.  the  parallel  spark-gap  of  the  tube  will  be  Non/ctrltat  higher, 
and  if  ('  and  .1  are  connected  and  then  connected  to  the  positive  ter- 
minal, this  will  give  the  lii</hcxt  parallel  spark-gap  of  this  particular 
tube,  and  it  does  not  make  any  difference  whether  the  positive  connec- 
tion is  then  attached  to  C'  or  -1.  This  difference  applies  to  tubes  which, 
when  connected  as  last  described,  have  a  parallel  spark-gap  of  1  inch 
or  less  on  a  static  machine  and  5  inches  or  less  on  an  .r-ray  coil. 

The  I'iffard  safety  .r-ray  tube  (Fig.  445)  was  designed  for  the  pur- 
pose of  doing  away  with  the  enclosing  shields  which  have  been  made 
for  .r-ray  tubes.  This  tube,  which  consists  of  two  4-inch  lead  glass 
bulbs  (two  bulbs  being  used,  as  it  was  found  impracticable  to  obtain 
a  large  bull)  of  the  same  opacity  as  the  smaller  bulbs),  was  made 
this  way  in  order  to  obtain  a  comparatively  large  space  inside  the 
tube,  so  thai  its  degree  of  vacuum  would  not  change  too  quickly. 
It  has  in  front  of  the  target  a  small  extension,  into  which  is  fused  a 


window  of  soda 


extensions  made  to  fit  on  this  projection,  so  that  the  rays  can  h< 


with  the  .r-rav 


was  intended  primarily  for  the  tro; 


but  it  can  also  be  used  for  light  ihioi'oscopic  work  and  radiography. 


MKD1CAL    ELECTRICITY    AND    HONTCKN    HAYS 


so  that  the  spark 
the}'  be  separated 
should  the  pointer 

In  usinu1  this  tube 


When  used  with  a  static  machine,  the  terminal  .1  is  connected 
to  the  positive  pole  of  the  machine.  Terminal  B  to  the  negative. 

The   pointer  is  placed   about    1'.    inches  away   from    the  connection  B. 

l"nder  no  circumstance  should  it   be  placed  more  than  '2  inches  awav 

from    B.      The   sliding   rod.-    1    and   '2   are   separate' 

just    disappear-.      I'nder    no    circumstance    should 

more   than    '•*>   inches,    and    under   no   circumstance 

be  brought   nearer  than   1    inch  to  the  terminal  B. 

for  treatment  purposes  the  exposure  is  usualh   much  shorter  than  when 

the  usual   tube  is  used,  owing  to  the  small  diameter  of  the  bulb,  and 

consequently,  the  part   treated  being  closer  to  the  target. 

When  used  on  an  .r-ray  coil,  the  connections  and  applications  above 
described  apply,  with  the  exception  that  the  terminals  on  the  coil  can 
be  separated  1  or  •">  inches,  never  more  than  that.  The  current  to 
excite  this  tube  should  not  be  very  strong  If  an  electrolytic  inter- 
rupter is  used,,  a  current  of  4  or  ">  amperes  is  all  sufficient;  if  a  mercury 
jet  interrupter  is  used,  a  current  of  '2  amperes  will  be  sufficient.  The 
point  to  be  specially  careful  about  is  bringing  the  pointer  too  close  to 
the  negative  terminal,  as  if  this  is  done  it  is  possible  to  release  so  much 
gas  that  it  will  be  necessary  to  have  the  tube  re-exhausted.  This, 
however,  cannot  occur  if  the  pointer  is  at  least  1  inch  away  from  B, 
and.  if  the  current  *ti'<  n</tlix  above  indicated  are  not  exceeded. 

Regulation  of  ./'-Ray  Tubes  for  Radiotherapy. — In  using  the 
.r-ray  for  therapeutic  purposes  the  most  important  point  to  pay  at- 
tention to  is  to  so  adjust  your  tube  that  the  maximum  number  of  rays 
generated  will  be  absorbed  in  the  tissue  under  treatment. 

At  the  present  time  no  standard  has  been  universally  adopted 
the  measurement  of  the  .r-ray,  and  until  such  i<  the  case  there  will 
a  ureat  difference  in  the  results  obtained  by  different  operators. 
a  general  way.  a  ray  that  when  the  hand  is  held  in  front  of  the 
iroscope  shows  the  outline  of  the  hand  distinctly,  but  not  the  bones, 
would  be  the  proper  one  for  the  treatment  of  all  superficial  skin  lesions. 
I-'oi  the  treatment  of  a  small  or  beginning  epithelionia  a  ray  that  would 


or 


how  the  bone-  of  i  he  hand   black,  but    very  di-tinctly.  would  be  the 

»e-t ,   ;md    for   internal    le-ions.  one   which   would   .-how   the   bones   very 

,  real   penetration,  but   the  screen  liiihtinu'  up  very 

irilliautlv.      The    1-1    of  the  hand  as  a   te.-l -object    wa-  formerlv  a  com- 


TIIK    .T-RAY 


707 


jnon,  though  an  exceedingly  dangerous,  custom.  It  is  responsible  for 
the  deaths  of  many  .r-ray  operators  from  cancer.  A  safe  substitute  is 
a  preserved  and  mounted  hand;  but  the  Benoist  radiochromometer 
affords  a  better  means  of  measuring  the  quality  of  the  .r-ray.  An  .r-ray 
filter  may  be  used  to  arrest  the  less  penetrating  rays.  Xot  a  single 
treatment  should  be  given  until  the  operator  has  learned  the  erythema, 
dose,  or  the  time  and  distance  which  will  produce  an  inflammation  of 
the  skin  with  his  apparatus  and  strength  of  current.  There  are  several 
different  ways  of  measuring  this,  including  the  author's  own.  Some 
diseases  are  most  favorably  influenced  by  fractional  doses  of  1  II.  (5 
Ilol/knecht  units  produce  a  mild  and  7  a  severe  dermatitis,  and  much 
more  than  7  H.  cause  ulceration  if  applied  at  one  time)  or  less  two  or 
three  times  a  week.  Other  cases,  notably  of  epithelioma,  are  best 
treated  by  massive  doses  of  7  II.  or  more,  either  at  one  session  or  divided 
in  two  sessions  not  more  than  a  day  or  two  apart.  Exact  dosage  is  con- 
sidered on  ]).  1154.  Good  results  have  been  obtained  from  the  use  of 
the  .r-ray  in  various  chronic  skin  diseases,  skin  cancers,  chronic  ulcers, 
enlargement  of  the  lymphatic  glands,  uterine  fibromyomata.  and  fre- 
quently a  great  deal  of  benefit  when  applied  for  internal  cancers;  in 
fact,  the  .r-ray  lias  been  used  for  many  chronic  conditions  with  vary- 
ing success,  which  will  doubtless  increase  with  the  adoption  of  exact 
methods  of  dosage.  When  a  tube  is  used  with  a  coil,  if  a  milliampere- 
meter  and  a  valve  are  used  and  the  parallel  spark-gap  of  the  tube 
noted,  one  can  form  some  idea  of  the  particular  ray  used.  However, 
this  does  not  tell  the  tale  exactly,  owing  to  the  number  of  interruptions 


in  the  primary  and  the  construction  of  the  .r-ray  coil  itself:  still,  it  is  a 
great  help  and  is  practically  the  best  guide  for  the  individual  operator 
himself,  for  if  he  notes,  in  addition  to  the  above  facts,  the  number  of 
amperes  in  the  primary  and  the  position  of  the  rheostat,  he  can  then 
duplicate  his  result  on  the  following  day.  When  using  a  tube  or  a  coil, 
one  of  the  greatest  sources  of  trouble  is  the  inverse  current,  which  not 
only  sets  up  a  great  number  of  wild  .r-rays.  but  al>o  apparently  shortens 
the  life  of  the  .r-ray  tube  itself.  This  bad  feature,  however,  can  now 
be  eliminated  by  means  of  the  Yillard  valve.  This  has  been  improved 
on  and  made  self-regulating. 

Figure  4-lf)  illustrates  an  .r-ray  tube  having  considerable  inverse  cur- 
rent. This  is  shown  in  the  first  place  by  the  green  ring,  and  in  the 
second  by  a  more  intense  green  at  11  .  \\hile  this  tube  would  light  up 
a  tluoroscope  very  well,  yet  for  taking  a  picture  it  would  not  be  a  very 


708 


MKDICAL    KI.KCTKIC1TY    AND    H()NT(iKN     KAYS 


good  tube,  owing  to  the  fact  of  the  cathode  stream  from  the1  inverse 
current  striking  the  glass  at  11"  and  causing  wild  .r-rays  to  he  generated 


B 


B 


IP     A 


Fi<_r.  440. — Osrillosropp  with  utiidin-ctional  current. 


THK    .r-KAY  709 

at  this  point.  Those  rays  interfere  with  the  clearness  of  the  picture. 
Inverse  current  is  most  pronounced  with  very  high-resistance  tubes 
when  excited  by  an  x-ray  coil.  This,  however,  is  done  away  with 
by  (lie  use  of  the  improved  Yillard  valve  (Fig.  4-17).  The  inverse  cur- 
rent can  also  bo  demonstrated  by  a  little  instrument  known  as  the 
oscilloscope  (Fiji.  44S).  When  placed  in  circuit  with  a  source  of  high- 
tension  current,  if  the  current  is  one  direction  only,  then  it  shows  a 
broad  violet  band  on  the  end  which  is  negative  (Fig.  449).  If  connected 
with  an  oscillating  current  of  high  tension,  it  shows  a  violet  band  of 
equal  width  on  both  sides  (Fig.  4oO).  If  connected  with  an  alternating 
current  of  high  tension,  but  the  alternations  being  stronger  one  way 
than  the  other,  then  it  shows  a  broad  band  on  one  end  and  a  smaller 
band  on  the  other  end,  as  in  Fig.  4">1.  This  device  is  especially  useful 
in  connection  with  the  Yillard  valve,  as  it  will  show  whether  the  valve 
is  in  good  working  order  and  cutting  off  all  of  the  inverse  current,  in 
which  case  the  oscilloscope  will  have  the  appearance  as  shown  in  Fig. 
i  ID. 

When  a  tube  has  boon  punctured  or  broken,  so  as  to  admit  a  con- 
siderable amount  of  air  at  atmospheric  pressure,  this  fact  is  indicated 
by  a  spark  passing  from  the  aluminum  cup  to  the  target.  If,  however, 
the  regulating  device  has  been  used  with  too  strong  a  current  or  for 
too  long  a  time,  then  the  tube  shows  a  violet  color  throughout  the  entire 
bulb,  and  this  is  also  the  appearance  when  a  tube  has  become  a  leaker. 
In  both  these  conditions  the  only  thing  to  do  is  to  send  the  tube  to  the 
maker  and  have  it  re-exhausted.  If  it  is  an  expensive  tube  it  will  very 
likely  give  better  satisfaction  if  you  send  the  electrodes  to  the  maker 
and  have  a  new  tube  made,  using  the  old  electrodes. 

Figure  452  illustrates  the  way  to  connect  an  .r-ray  lube  in  circuit 
with  an  oscilloscope  and  a  ventril  tube. 

Care  of  the  Fluoroscope.—  A  fluoroseopo  (Fig.  4oo)  requires,  in  the 
first  place,  to  be  kept  in  a  moderately  cool  place.  It  should  also 


Fiji.  4~>3. — Oryptosropc  <>r  l>ox  fluoroscopp. 

have  a  cover  made  to  go  over  the  eye-piece1,  so  that  when  not  in  use 
no  dust  or  dirt  can  fall  on  the  screen,  as  the  screen  is  made1  of  one  of 
the  most  sensitive  salts  and  a  very  little  dust  will  cause  it  to  decom- 
pose, thus  losing  its  fluorescent  property.  A  -hoot  of  lead  glass  over 
the  screen  protects  this  and  also  the  observer's  eyes.  After  a  varying 
,Vni:th  <>f  time  the  screen  begins  to  deteriorate  at  the  edge.  This 
tlctrriordlinn  is  indicated  by  a  change  of  folnr.  \\hen  the  screen  is  new 
and  in  Li'ood  condition  it  will  have  an  apple-green  color;  as  it  begins  to  de- 


/  1U  MEDICAL    ELECTRICITY    AND    HONTCKN     RAYS 

teriorate.  the  edge  will  begin  to  turn  color,  and  this  will  extend  finally 
over  the  entire  screen,  it  being  an  orange  brown.  This  change  is 
gradual,  and  as  it  occurs  the  fluorescence  of  the  screen  diminishes; 
however,  it  does  not  cease  entirely,  so  that  it  frequently  happens  that 
a  physician  finds  that  he  is  not  able  to  see  as  well  with  the  fluoroscope 
as  formerly .  and  he  will  imagine  that  there  is  something  the  matter  with 
the  tube  or  the  machine.  He  most  often  concludes  that  the  trouble 
is  with  the  tube,  and  will  order  a  new  tube,  but  he  fails  to  get  a  better 
result .  owing  to  the  fact  that  the  trouble  lies  with  the  screen  and  not  with 
the  apparatus.  A  hand-guard  of  zinc  protects  the  operator's  hand. 

An  operating  fluoroscope  is  made  with  the  enclosed  box  fastened 
over  the  operator's  eyes,  but  with  the  fluorescent  screen  hinged  so  that 
it  can  be  turned  back.  Part  of  the  time  the  operator  is  looking  at  the 
x-ray  image  and  part  of  the  time  directly  at  the  field  of  operation.  It 
may  be  provided  with  an  orthodiascopic  feature. 

Fluoroscopy. — In  the  first  place,  remember  that  the  .r-rays  are 
inii*ihl<-  and  that  the  green  fluorescence  of  the  tube  is  due  to  the  cathode- 


Fit',    l.Vt,— Tin     John-ton    finoro.-cope.      The  operator  stands   at    one   side   instead   of  in   n 


rays  and  r-rays  which  strike  against  the  glass,  causing  it  to  fluoresce^ 
A  tube  made  of  lead  glass  instead  of  fluorescing  yrcni,  fluoresces  blue. 
'I'h'-  platinobarium  cyanid  crystals  when  struck  by  the  .r-ray  fluoresce, 
:::  ;  it  is  'hi-  effect  that  we  see  ;in<l  not  the  .r-ray  itself.  The  more 
in  ,n  frnfi mi  the  rays  are.  the  more  hriUiunt  will  usually  be  the  screen. 
'he  hand  i-  held  on  one  side  of  the  screen  then  the  .r-rays  act  as 
;  illows:  Part  of  them  strike  the  screen  directly.  This  causes  the 
.  ,  .  :  •  :  i!  ,  in-sce  at  its  maximum.  The  rays  that  are  in  line  with  the 
soft  parts  of  the  liand.  part  of  them  are  absorbed  and  part  pass  through 
;md  strike  the  screen,  so  that  the  screen  directly  under  the  soft  parts 
does  ),,,!  iiuore-.cc  us  briirhtlvas  where  there  has  been  no  absorption  of 
the  rays;  con-equently,  this  portion  of  the  screen  appears  somewhat 
The  rays  that  are  in  line  with  the  bones  are  practically  all 
ali-orbed.  _;  'hat  we  have  a  very  soft  tube,  and  consequently 

the   -en-en   directly   under  the  bones  does  not    fluoresce  at    all.   so  that 
i'    at  'I  iears  black. 


THK    .T-IIAY  711 

From  this  description  yon  will  appreciate  the  fact  that  using  the 
screen  amounts  practically  to  transillumination;  consequently,  in  order 
to  do  the  best  fluoroscopic  work  it  is  absolutely  necessary  to  have  a  practi- 
cally dark  room,  and  to  be  in  the  room  for  at  least  five  minutes  before 
attempting  to  use  the  fluoroscope.  The  tube  should  be  one  in  which  the 
penetration  of  the  rays  can  be  varied  '.  In  order  to  obtain  the  best  detail, 
rays  of  the  least  penetration  that  will  be  sufficient  to  go  through  the  part 
to  be  examined  will  give  the  yrt'otcxt  amount  of  contrast.  A  32-candle- 
power  ruby  lamp  in  a  large'  room  or  a  Hi-candle-power  ruby  lamp  in  a 
very  small  room  will  give  ample  light  to  work  in  an  otherwise  perfectly 
dark  room  and  interferes  very  little  with  the  use  of  tin-  fluoroscopic 
screen.  For  the  most  exact  work,  however,  the  rooms  should  be  en- 
tirely dark  when  an  uncovered  screen  is  used,  or  if  this  is  impracticable, 
the  usual  box  fluoroscope  must  be  used.  In  any  case  daylight  should 
be  excluded. 

Cathode  Rays.  —  The  cathode  stream  has  certain  properties  which 
it  is  necessary  to  explain  in  connection  with  those  of  the  x-ray.  Every- 
thing points  to  the  conclusion  that  it  is  a  stream  of  material  particles 
traveling  at  the  rate  of  about  20,000  miles  a  second.  This  is  only  the 
average1  velocity.  Each  particle  travels  at  a  rate  of  speed  depending 
partly  upon  its  size  and  partly  upon  the  voltage  under  which  it  is  im- 
pelled. Many  of  the  cathode  particles  encounter  ions,  atoms,  and 
molecules  which  arrest  their  motion  toward  the  anticathode. 

Some  of  the  particles  forming  the  cathode  ray  are  probably  electrons 
and  carry  the  same  amount  of  negative  electricity  as  hydrogen  atoms  in 

an  electrolytic  liquid  electrostatic  units,  or 


ooo.oooooo.ooo.ooo 

coulombs),  and  their  size  is  about  j—  ^  or  .)()U()  that  of  a  hydrogen  atom. 
Other  cathode  particles  are  probably  aggregations  of  electrons  and 
others  molecules  or  aggregations  of  molecules.  The  particles  start 
perpendicularly  from  every  point  on  the  front  surface  of  the  cathode  and 
proceed  in  straight  lines  until  they  strike  some  solid  substance1.  They 
are  deflected  toward  a  horseshoe  magnet  and  exercise  a  certain  amount 
of  mutual  repulsion.  Consequently,  in  an  .r-ray  tube  the  focus  point 
upon  the  anticathode  is  much  further  from  the  cathode1  than  would 
be  the1  case1  if  the1  e-athode  rays  starting  perpendicularly  fre>m  its  front 
surface1  proceeded  in  perfectly  straight  line^  and  therefore  met  at  its  cen- 
ter of  curvature1.  The1  impact  of  the1  cathode1  stream  produces  mo- 
tion.  and  will  turn  a  pimvhcel  plae-ed  inside1  the1  vacuum  tube.  It  pro- 
eluces  sufHe-ient  heat  te>  melt  the1  platinum  or  even  the1  tungsten  elisk  in  an 
.r-ray  tube.  It  produce's  fluorescene-e  of  the  glass  wall  of  the  tube  and  of 
many  other  substances;  some  of  the  phosphorescent  colors  produced  are1: 
with  sulphate  of  copper,  a  faint  green;  with  >ulphate'  of  coppeT  containing 
a  trace  of  sulphate  of  manganese1,  a  bright  gree-n:  none1  with  sulphate 
of  strontium;  with  sulphate  of  strontium  containing  a  trace  of  sulphate 
of  manganese,  a  bright  red:  with  barium  sulphate,  a  faint  dark  violet; 
with  barium  sulphate  containing  a  trace  of  sulphate  of  manganese, 
a  dark  blue-:  with  magnesium  sulphate,  a  red;  with  magnesium  sul- 
phate and  a  trace1  of  sulphate  of  manganer-e.  an  intense  dark  red:  with 
sulphate-  of  zinc,  a  bluish  color;  with  sodium  sulphate1  containing  A 
of  1  per  ce'iit.  of  sulphate  of  manganese,  an  intense-  brownish  yellow; 
with  cadmium  sulphate',  a  yellenv:  with  iluorid  of  cak'ium.  a  faint  blue; 
with  Huoriel  of  calcium  with  a  trace'  of  hydrid  of  manganese1,  an  intense 
blue.  The  most  striking  effects,  as  may  be  seen  above1,  are  on  "solid 
solutions."  These  are  termed  bv  two  salts,  one  iiivatlv  in  exce'ss  of  the 


,  12  MKDICAL    KLI-XTKK'ITY    AM).   HONTCKN    KAYS 

other,  precipitated  simultaneously  from  a  watery  solution.  The 
cathode  rays  produce  upon  the  glass  wall  of  the  tube  shadows  of  any 
-olid  body  which  may  intercept  their  path  through  the  vacuum.  They 
render  any  gas  through  which  they  pass  a  conductor  of  electricity. 
They  carry  a  charge  of  negative  electricity  and  any  solid  substance 
which  they  strike  gives  out  generally  diffused,  not  alone  perpendicular, 
cathode  ray.-,  and  also  .r-rays.  Cathode  rays  do  not  emerge  from  a  glass 
vacuum  tube  in  any  appreciable  amount  unless  a  thin  sheet  of  aluminum 
is  hermetically  sealed  into  an  opening  in  the  glass.  The  aluminum 
is  tran-parent  to  these  rays  and  acts  as  a  sort  of  window  if  placed  at  the 
spot  where  the  cathode  rays  impinge. 

Iler/'s  discovery  that  the  cathode  rays,  as  he  thought  them  to  be, 
would  penetrate  gold-leaf,  was  made  by  covering  a  small  piece  of  ura- 
nium irlass  with  gold-leaf,  leaving  an  uncovered  edge  of  glass  exposed 
all  round.  Bringing  this  piece  of  glass  near  the  tube  and  opposite 
the  cathode  pole,  he  found  that  the  piece  of  glass  which  was  uncovered 
became  fluorescent  and  that  it  increased  the  vacuum  still  more  within 
the  tube,  even  the  glass  back  of  the  gold-leaf  was  rendered  fluorescent. 
This  apparently  was  an  effect  of  the  x-ray,  but  at  that  time  (1892)  it 
was  not  recognized  as  such.  Lenard,  a  couple  of  years  later,  in  his 
experiments  with  the  rays  that  go  by  his  name,  found  that  phosphores- 
cence was  sometimes  caused  even  beyond  substances  like  aluminum. 

If  the  aluminum  is  .00265  millimeter  thick  the  rays  pass  through  in 
sufficient  amount  to  cause  visible  light  and  produce  phosphorescence. 
The  most  phosphorescent  substance,  according  to  Prof.  ,1.  ,L  Thomson 
(now  Sir  Joseph  Thomson),  whose  book  on  the  "Transmission  of  Electric- 
ity through  Oases"  is  a  recognized  source  of  information,  is  tissue-paper 
soaked  in  pentadekylparatoleketon.  These  cathode  rays  outside  the 
tube  are  called  Lenard  rays.  They  spread  out  very  diffusely  and  pro- 
duce shadows  larger  than  should  occur  geometrically.  They  cause 
photographic  effects,  are  arrested  by  quart/,  but  alum  is  transparent 
to  them.  But  some  of  these  effects  may  be  due  to  the  presence  of  the 
.r-ray.  Lenard  rays  discharge  negatively  or  positively  charged  bodies, 
a-  do  t  he  x-rays. 

Cathode  rays  may  be  shown  in  an  ordinary  electric-light  bulb  by 
connecting  one  wire  with  a  piece  ot  tin-foil  pasted  on  the  outside  of  the 
bulb  at  a  distance  from  the  metal  part  of  the  bulb.  The  latter  is  con- 
nected with  the  other  electric-light  wire.  This  experiment  and  the 
other,  of  making  the  same  connections  between  the  bull)  and  the  wires 
from  an  .r-ray  coil,  u'enerally  resul'  in  burning  out  the  incandescent 
filament  and  spoiling  the  lamp.  The  vacuum  in  electric-light  bulbs  is 
too  1< iw  ti i  <retiernte  ;r-rays. 

Kanalstrahlen,  or  channel  rays,  were  discovered  by  (ioldstein  in 
lxyt>.  who  found  that  with  a  perforated  cathode  <  Fig.  }.">.">)  certain 
ra\>  occurred  behind  the  cathode  which  did  not  seem  to  be  deflected 
!;\  a  maunet,  and  whose  only  known  proper1  v  i-  that  ot  bemti  accom- 
panied li\-  lumino-itv.  Thomson'.-  explanation  ot  these  is  that  they 
are  lets  of  phosphorescent  u'as  produced  bv  a  sort  ot  explosion  at  the 
cathode. 

le  cent  experiments  bv  \\  ien  and  bv  .1.  .1.  Thomson'  have  shown  that 

the    kanal-t  rahlen    of    (ioldstein    are    charged    with    po-itive   electricity. 

ire  deviated  b\    a  mau'tieti'1  field  or  bv  an  electrostatic  field  in  the 

oppo-ite  direction    from    that    followed    by    the   cathode   rays.      But    the 


TIIF.    .r-HAY 


713 


magnetic  field  must  be  very  much  more  powerful  and  the  means  of 
observation  much  more  exact  than  in  the  latter  case. 

Channel  rays  may  be  studied  by  having  an  enlargement  of  the  tube 
back  of  the  cathode,  containing  a  fluorescent  screen.  They  carry  a 
positive  charge  of  electricity,  and  their  deflection  by  a  magnetic  field  is 
evidenced  by  the  displacement  of  the  fluorescent  spot  on  the  screen. 

ClKinncl  ra//.s  ionixe  gases  through  which  they  pass. 

lonization  by  Cathode  and  by  Channel  Rays.1-  The  cathode  rays  in 
passing  through  an  atom  repel  or  attract  the  corpuscles  which  are  eon- 


Kanalstrahlen  or  channel  ray?. 


tained  therein  and  communicate  kinetic  energy  or  motion  to  them. 
If  this  energy  reaches  a  certain  value,  a  corpuscle  escapes  from  the  mole- 
cule in  such  a  way  that  there  is  a  production  of  a  free  corpuscle  and  of  a 
positively  charged  atom. 

A  Wehnelt  cathode  is  one  covered  with  lime  and  heated  and  has  a 
hole  in  it.  It  affords  channel  rays  in  abundance,  and  is  suited  to  the 
production  of  very  soft  .r-rays  with  a  current  of  1000  volts  or  less. 

Positively  Charged  Particles  in  a  Vacuum  Tube.  —  As  intimated 
in  the  last  paragraph,  it  seems  moderately  certain  at  the  present  writing 
that  there  are  such  things  as  positively  charged  particles  in  motion 
inside  a  (leissler  tube  which  has  a  vacuum  of  about  y^o  atmosphere 


If  this  be  really  so,  it  does  not  necessarily  interfere  with  our  conception 
of  the  cathode  stream,  but  it  may  to  a  certain  extent  cause  us  to  revise 
our  idea  that  the  latter  is  practically  the  sole  factor  in  the  transmission 
of  electricity  through  gases  and  that  the  current  i>  unidirectional,  from 
t  he  cathode  to  the  anode. 

The  energy  of  the  .r-rays  is  ^  that  of  the  cathode  rays  which 
produce  i  hem  '  M.  Wien)  . 

The  energy  of  the  x-ray  is  proportional  to  the  energy  of  the  cathode 
ray-  producing  it.  The  energy  of  a  cathode  particle  is  proportional  to 
the  fourth  power  of  its  velocity. 

Conversion  of  ./-Rays  into  Heat.-  The  absorption  of  the  .r-ray 
in  passing  through  a  sheet  of  metal  causes  a  certain  amount  of  energy 
to  be  converted  into  heat.  Adams-  has  measured  this  amount  of  heat 
by  very  delicate  apparatus. 


714  MF.IMCAI.    KLKCTUICITV    AND    RONTdKN    HAYS 

Sonic  of  liis  results  agree  with  observations  made  upon  the  x-ray 
by  other  workers  with  different  methods.  These  are:  the  percentage 
of  .r-ray  absorbed  is  independent  of  the  intensity  of  the  radiation; 
there  is  very  little  surface  effect  like  that  which  reflects  or  disperses 
or  absorbs  ordinary  light  :  a  smaller  proportion  of  the  .r-ray  is  absorbed, 
by  a  second  similar  metallic  sheet  than  by  the  first  one;  but  this  dot's 
not  hold  good  in  the  case  of  .r-rays  passing  first  through  aluminum 
and  then  through  silver;  they  are  less  penetrating  for  silver  than  nor- 
mally. 

An  observation  made  by  Adams'  thermometrie  method  which  differs 
from  that  supposed  to  be  shown  by  other  methods  is  that  the  amount 
and  quality  of  radiance  which  passes  through  two  sheets  of  different 
metals  is  the  same  no  matter  in  what  order  the}'  are  placed.  Accord- 
ing to  this  observation  the  ./--ray  undergoes  no  change  in  quality  in  pass- 
ing through  different  metals. 

The  original  radiation  consisting  of  rays  of  less  penetrating  power 
and  rays  of  more  penetrating  power  encounter  a  sheet  of  metal  which 
.-lops  a  greater  proportion  usually  of  the  less  penetrating  rays.  The 
rays  which  pass  to  the  second  metallic  sheet  penetrate  this  in  greater 
proportion,  not  because  they  are  rays  which  have  been  rendered  more 
penetrating  by  passage  through  the  first  metal,  but  because  they 
are  the  original  more  penetrating  rays  from  which  the  less  penetrating 
ray?  have  been  separated  by  the  first  sheet  of  metal. 

Assuming  his  observation  about  the  different  metals  to  be  correct, 
we  <hould  draw  the  following  conclusions: 

While  it  is  true  that  some  metals,  like  silver,  absorb  different  wave- 
lengths of  the  .r-ray  from  other  metals,  like  aluminum,  there  is  no  change 
in  the  ./"-ray,  and  the  total  portion  arrested  is  the  same  no  matter  in 
which  order  the  metals  are  placed  and  in  which  order  the  different 
Wave-lengths  are  arrested. 

The  present  author  has  always  felt  that  this  was  probably  true.  but. 
of  course,  to  be  theoretically  modified  by  the  consideration  of  secondary 
ravs.  usually  of  low  penetration. 

A'-rays  Within  the  Vacuum  Tube. — Experiments  by  Battelli1 
showed  that  a  photographic  plate  in  a  light-proof  envelope  was  not 
affected  \vhen  inside  an  /-rav  tube  in  operation.  This  would  indicate 
that  with  the  tube  employed  the  .r-rays  radiated  chiefly  if  not  alto- 
gether from  the  external  surface  of  the  glass  tube.  This  experiment 
should  he  repeated  by  a  number  of  observers  because  t  he  result  appears 
parad<  ixic. 

Measurement  of  Velocity  of  ./--Ray.-  K.  Marx's  method-  employs 
the  same  current  to  excite  two  vacuum  tubes,  one  an  ordinary  x-ray 
tube  ;nid  the  other  a  tube  exhausted  to  an  extremely  high  vacuum. 
The  /-ray  Chines  upon  this  second  t  ube.  and  if  t  he  .r-rays  strike  upon  the 
cathode  df  this  tube  it  excites  secondary  x-rays.  The  combined  effect 
df  the  primary  and  secondary  /-rays  in  the  -econd  tube  is  greatest  when 
the  impact  of  the  exciting  cathode  particles  and  of  the  exciting  /-rays 
from  the  other  tube  are  synchronous.  A  series  of  experiments  is  made, 
varyinir  the  lei  mi  h  of  the  conducting  wire  between  the  two  tubes  without 
altering  the  di-taiice  between  the  tube-  themselves.  The  result  shows 
that  the  velocity  of  the  /-ray  in  the  air  is  the  same  as  that  of  electricity 
1n  copper  wire,  about  1  *.").()()()  miles  a  second. 

;  Nu< iv  i  ( 'inicnti 
'-  IM,v-.  /..-it..  No. 


THK    X-KAY  715 

Discharge  Rays  (Gorman  F.ntladungs  Strahlen). — An  electric  spark, 
even  in  the  upon  air,  gives  origin  to  radiations  which  produce  thermo- 
luininescence  and  also  ioni/e  gases.  rrh(\v  have  something  like  the  pene- 
trating properties  of  the  x-ray.  Laird1  finds  that  those  rays  originate 
chiefly  from  the  vicinity  of  the  cathode  and  that  they  do  not  deviate 
under  the  influence  of  a  magnetic  field.  They  resemble  the  x-ray  in 
the  fact  that  they  are  discontinuous  vibrations,  not  a  uniform  succession 
of  waves  like  those  of  light. 

FORMS  OF  ELECTRIC  GENERATORS   ADAPTED  TO  EXCITING  AN  X-RAY  TUBE 

The  Static  Machine. — The  simplest  form  of  apparatus  is  a  static 
machine,  and  any  large  and  powerful  one  will  produce  quite  a  good 
re-radiance.  The  static  machine  produces  directly  currents  of  very  high 
voltage  and  very,  very  low  amperage,  continuous,  or  with  series  gaps 
rapidly  interrupted,  all  in  the  same  direction,  and  of  very  uniform  in- 
tensity. All  that  is  necessary  is  to  connect  the  prime  conductors  of 
the  static  machine  with  the  corresponding  electrodes  of  the  x-ray  tube. 
Multiple  spark-gaps  should  be  ready  for  use  upon  each  of  the  cords 
leading  to  the  tube,  and  a  very  useful  bit  of  apparatus  is  a  pole-changer, 
by  means  of  which  the  polarity  of  the  conducting  cords  may  be  changed. 
The  polarity  of  the  static  machine  cannot  be  changed  at  will  and  the 
polarity  of  the  x-ray  tube  cannot  be  changed  at  all.  Sometimes  it  is 
inconvenient  to  place  the  tube  in  such  a  position  that  a  cord  can  pass 
directly  from  its  negative  pole  to  the  negative  pole  of  the  static  machine, 
and  in  such  a  case  the  connection  is  made  indirectly  by  means  of  the  pole- 
changer.  To  do  satisfactory  work  a  static  machine  must  have  at  least 
eight  revolving  plates,  30  inches  or  more  in  diameter;  and  a  motor,  either 
water  or  electric,  by  means  of  which  the  plates  may  be  made1  to  revolve 
250  or  more  times  a  minute.  The  larger  and  more  powerful  the  machine, 
the  better  x-ray  work  can  be  done  with  it.  \Yilliams  states  that  tin- 
static  machine  used  for  x-ray  work  at  the  Massachusetts  General 
Hospital  in  Boston  has  revolving  glass  plates  whose  combined  weight 
is  a  ton  or  '2000  pounds.  The  static  machine  has  certain  limitations: 
it  is  not  suitable  for  warm  or  damp  climates;  it  is  uncertain  in  action 
iu  i lamp  weather,  although  this  may  be  obviated  by  care  in  construc- 
tion and  maintenance,  the  author's  machine  having  never  refused 
to  work  winter  or  summer,  rain  or  shine.  It  usually  gives  a  relatively 
small  amperage  and  so  takes  about  five  times  as  long  to  make  a  picture 
as  a  coil  does;  it  is,  in  that  case,  unsuited  for  radiography  of  the 
thicker  portions  of  the  body.  It  gives  a  steady  brilliant  radiance  which 
is  excellent  for  fhioroscopic  examinations  and  produces  less  of  the  photo- 
chemic  rays  than  the  coil,  and  is  less  likely  to  produce  dermatitis 
in  either  patient  or  operator  during  such  examinations.  It  is  less 
suitable  for  radiotherapy  because  of  the  longer  exposures  required;  and 
it  is  especially  necessary  to  note  that  SOUK-  of  the  worst  accidental 
burns  that  have  conn-  to  the  author  for  treatment  have  been  produced 
by  the  static  machine.  It  can  be  used  in  places  where  tin-re  is  no  electric 
current  obtainable.  Its  cost  for  equally  good  radiographic  results  is 
very  much  greater  than  that  of  a  coil. 

The  Baker  static  machine  has  revolving  plates,  made  of  a  dozen  sheets 
of  linen  paper  soaked  in  shellac  and  compressed  into  a  disk  as  hard  as 
iron,  but  without  its  brittleness.  The  plates  may  be  made  larger  anc 
1  Phvs.  Rev.,  33,  1911,  512. 


7l()  MKDICAI.    KLKCTHinTY    AM)    H(")\T<;KN    HAYS 

revolve  at  a  much  higher  speed  than  glass  plates.  The  machine  produces 
an  excellent  .r-ray.  but  not  so  powerful  as  that  from  a  transformer  or  an 
unfluctuating  converter. 

The  static  machine  gives  a  more  uniform  discharge  and.  according 
to  some  observations,  it  may  witli  a  tube  of  a  certain  degree  of  vacuum 
give  .r-rays  of  much  more  nearly  a  single  rate  of  vibration  than  the 
induction-coil  with  its  discharge  varying  at  every  instant.  Piffard1 
and  others  conclude  from  this  that  the  static  machine  is  preferable  to 
the  induction-coil  for  radiotherapy. 

Millia ////»raac  of  a  Static  Machine  When  l's<d  far  .r-Rnij  Work. — 
Contrary  to  what  is  commonly  the  case  with  an  induction-coil,  the 
milliamperemeter  shows  more  current  passing  from  a  static  machine 
when  the  resistance  of  the  .r-ray  tube1  is  great  than  when  the  vacuum  is 
low  and  the  resistance  small.  Two  factors  are  concerned:  one  is  that 
the  output  of  thi'  static  machine  is  at  its  .Maximum  when  its  prime 
conductors  are  far  apart  and  the  resistance  is  as  great  as  possible; 
another  is  that  static  electricity  is  of  such  high  voltage  that  a  brush  dis- 
charge from  the  terminals  of  the  tube  or  any  other  metal  points  in  the 
circuit  allows  more  current  to  go  through  the  milliamperenieter  than 
gets  through  the  tube  if  the  vacuum  is  high. 

Increasing  the  resistance  in  the  circuit  by  raising  the  degree  of 
vacuum  in  the  tube  increases  the  output  of  the  st at  ic  machine,  but  much 
of  this  increase  is  wasted. 

Increasing  the  resistance  in  the  circuit  by  the  introduction  of  a 
spark-gap  increases  the  output  without  increasing  the  resistance  of  the 
tube,  and  consequently  the  increased  output  is  directly  available  for 
increasing  the  intensity  of  the  x-ray. 

Parallel  Spark  Ba<-k<d  Cp  hi/  an  .c-Raij  Tuhc  Actuated  (>;/  a  Static 
Mar/, int. — The  same  .r-ray  tube  which  will  back  up  a  spark  of  about 
")  inches  with  an  induction-coil  will  back  up  one  of  only  about  1  inch 
with  a  static  machine.  The  author  regards  this  as  attributable  to  the 
greater  loss  of  high-tension  static  electricity  by  a  brush  discharge 
from  the  terminals  of  the  tube  and  from  metallic  points  about  the 
ords. 

'arunt/i  aj  an  x-Raij  Tnhc  far  [  *<  irit/i  a  Static  Machine. 
a  static  machine  the  tub'1  employed  should  be  one 
manufacturer  in  good  condition  for  use  with  this 
oubtless  remain  in  perfect  condition  for  a  very  long 
discharge  does  not  usuallv  heal  up  the  tube  and  so 
Miles  of  gas.  A  lube  for  Use 


1    of  use.       If  the  1  ube  i 
d  be  used  very  rarely  indeed 
Lowering   the   vacuum   a   very   little   too   much 
Use  with  the  static  machine,  because  the  current 
iii^h    to    scatter   panicles  of    metal    through    the 
excess  of  gas.      It'  there  is  one  of  the  spark  regu- 
found    necessary   to   connect    the   negative   wire 
im    reducer  and    no]    depend    upon    leaving    the 
:d    attached    to    the    cathode    and    turning    the 
Iven  with  a  direct   connection   it   mav  be  found 
York  Mc<l.  Jour..  Sept.  i:>.  I'M).-,. 


TIIK    .r-RAY  717 

that  the  amperage  of  the  current  is  insufficient  to  liberate  the  necessary 
amount  of  gas. 

If  one  lias  an  induction-coil  as  well  as  a  static  machine,  it  is  an 
extremely  easy  mutter  to  regulate  the  vacuum  in  the  tube  by  the  use  of 
the  induction-coil  and  then  to  use  the  static  machine  to  run  the  lube. 
This  might  be  done  for  some  treatment  or  experiment  where  a  lonu, 
mild,  uniform  exposure  was  desired. 

If  LCI/I  lot  /V//'.s  are  used  to  act  uute  an  .r-ray  t  ube  with  a  static  machine 
they  should  not  be  larger  than  pint  bottles.  The  internal  armatures  un- 
connected with  the  prime  conductors  and  the  external  armatures  with 
the  poles  of  t  he  .r-ray  tube. 

The  voltage  from  a  xtatir  ui/ir/i/'/n  is  very  high  and  is  measured  by  tin- 
distance  across  which  a  spark  will  pass  between  the  two  poles  or  by  an 
electrostatic  voltmeter  or,  indirectly,  by  an  electrometer.  The  latter  is 
a  refinement  of  the  simple  electroscope,  in  which  the  two  gold  leaves 
separate  when  they  both  become  charged  with  the  same  kind  of  elec- 
tricity bv  bringing  a  changed  body  near  the  rod  from  which  they  are 
suspended.  The  electrometer  shows  the  density  of  the  electric  charge 
at  any  part  of  the  apparatus  or  of  the  patient,  and  this  varies  with  the 
voltage  of  the  source  of  electricity  and  is  also  greatest  upon  the  surface 
and  (-specially  upon  sharp  projections  from  the  surface.  The  voltage 
produced  by  a  good  static  machine  is  100. 000  or  more.  The  amperage 
is  very  small  indeed,  but  is  still  demonstrable  by  means  of  a  milliam- 
peremeter  of  the  movable  wire  coil  variety  (d'Arsonvul  milliumpere- 
meter)  or  by  a  pole  detector  in  which  the  electrolytic  effect  of  the 
current  produces  a  red  color  in  the'  liquid.  The  physical  and  physiologic 
effects  of  the  static  discharge  are  due  almost  entirely  to  its  tension  or 
voltage  and  scarcely  at  all  to  its  intensity  or  current  strength  or  am- 
perage. It  has  polarity,  however,  and  the  proper  direction  of  the  cur- 
rent is  necessary  for  the  excitation  of  an  .r-ray  tube. 

An  Induction-coil  Operated  by  a  Galvanic  Battery. — The  battery 
should  be  the  equivalent  of  30  to  (>0  Leclanchi'-  cells  (8  to  16  cells  will  do) 
connected  in  series,  and  the  current  from  this  should  pass  through 
the  primary  coil  of  thick  copper  wire  surrounding  a  core  of  soft-iron 
rods.  The  primary  coil  is  slipped  inside  the  secondary  coil,  to  which  it 
is  not  connected  in  anv  way.  The  secondary  coil  consists  of  thousands  of 
turns  of  very  fine  copper  wire  carefully  insulated  and  terminating  in  two 
poles  from  which  the  conducting  cords  are  to  lead  to  t'he  .r-ray  tube. 
Each  time  that  the  current  begins  to  flow  through  the  primary  coil 
a  wave  of  electricity  is  induced  in  the  secondary  coil,  and  again  when 
the  current  is  turned  off.  The  break-current  induced  in  the  secondary 
coil  is  stronger  and  in  an  opposite  direction  from  the  make-current. 
The  primary  current  is  turned  on  and  off  very  rapidly  by  a  vibrator. 
\\hen  the  current  is  turned  on,  the  primary  current  causes  the  soft- 
iron  core  to  become  a  temporary  mairnet  and  this  attracts  the  iron 
armature,  whose  motion  toward  the  core  btvak<  the  contact  and  the 
current  ceases.  The  iron  core  ceases  to  be  a  magnet  and  the  arm-Mure, 
which  is  upon  a  spring,  returns  to  its  original  position  and  the  contact 
is  airam  made.  Such  a  coil  requires  a  condenser  of  many  sheets  of 
lead  toil  separated  by  sheets  of  mica  or  paper  to  take  up  the  extra 
currents  occurring  in  the  primary  coil. 

The  value  ot  a  condenser  for  an  induction-coil  used  to  excite  an 
.r-ray  t  ube  except  wit  h  an  electrolytic  interrupter  is  easily  demonstrated. 
The  interrupter  works  more  steadily  and  the  fluoroscopic  and  radio- 


71S 


MKD1CAL    KLKCTUK  1TY    AM)    RONTGEN    HAYS 


uraphic  results  arc  much  l>cttcr.  rrrcatincii1s  and  the  lighter  forms 
of  fluoroscopic  and  radiographic  work  may  he  very  \vcll  done  with  such 
a  coil.  Kiirure  -I")!)  \vas  made  with  a  coil  and  galvanic  hattery  in  1800 
hy  Dr.  T.  W.  Kilmer,  then  one  of  my  assistants  at  St.  Bartholomew's 
clinic. 

An  Induction-coil  and  Storage-battery.-  The  100- volt  storage- 
hattery  of  an  electric  aiitomohile  will  operate  any  kind  ot  a  coil  and 
interrupter.  The  storage-hat  tery  itself  need  no!  he  carried  into  the 
room  in  which  the  coil  is  placed.  It  is  only  necessary  to  run  a  douhle, 
heavily  insulated  wire  from  the  charging  plug  of  the  aiitomohile  to  the 


./•-ra\  apparatus.  The  .-mailer  portahlc  storage-batteries  in  which  each 
'••  1!  \veitih.~  about  10  pound.-  operate  an  s-inch1  coil  with  a  mechanic 
interrupter  very  u<-ll.  About  six  sucli  cells  are  re<iuire(l  and  (hey  have 
'<i  be  -cut  ''i  a  power-house  to  he  recharged  when  exhausted.  This 
hi  nn  nf  apparat  us  has  given  me  sal  is  fact  ory  service  in  the  t  reat  meiit  of 
Ip  ts'  homes  where  there  \\-as  no  electric  current.  In  such 

ca-c-  i'  i-  much  more  practicable  than  a  galvanic  battery.  The  rent 
1  'I  -uch  ;i  ba  n  i  t  v  , ,)'  <jx  (.(-Us  i-  oiilv  about  ten  dolla  rs  a  month,  including 
fi-chai  '  •  may  be  obtained  in  everv  town  where  electric 

powei    i-    ii-i-d.      Tlieii    capacity   i-  .'!0  ampere  hours.      The  efficiency  is 


THE    .r-KAY 


719 


not  grout  enough  for  the  heavier  kinds  of  radiography  and  it  would  not 
he  selected  for  office  work  if  an  elect  ric-light  ing  current  were  available. 
It  forms  the  best  practicable  portable  source  of  current  for  .r-ray  work 
where  there  is  no  electric  light. 

Some  rheostat  resistance  should  always  be  used  with  a  storage-bat- 
tery because  of  the  possibility  that  the  interrupter  may  stick  and  a  con- 
tinuous heavy  current  burn  out  the  .r-ray  coil  or  damage  the  storage-bat- 
tery. The  plates  in  the  latter  may  "buckle." 


An  Induction-coil  Operated  by  the  Electric-lighting  Current. — 

This  is  one  of  the  most  practicable  and  satisfactory  methods  (Fig.  457, 
.1).  The  current  generally  used  is  the  1  10-volt  direct  current, 
though  the  alternating  current  may  be  used  witli  a  slight  change  in  the 
apparatus.  The  apparatus  is  connected  at  any  ordinary  electric-light 
socket,  the  current  passing  through  an  interrupter  which  makes  and 
breaks  t  he  current  several  hundred  or  several  thousand  t  imes  a  minute. 
Some  interrupters  used  are  mechanic,  depending  on  an  electromagnetic 
vibrator,  or  on  the  making  and  breaking  of  the  contact  between 
mercury  and  a  solid  metal.  The  metal  may  dip  into  the  mercury  and 
be  withdrawn  or.  what  is  much  more  satisfactory,  a  whirling  jet  of 
mercury  may  Mrike  against  metal  plate-  fixed  in  the  insulated  wall  of 
the  vessel  surrounding  the  mercury  turbine.  Kitherof  these  mercurv 
interrupters  requires  a  motor  to  operate  it  and  requires  a  greater 
amount  of  attention  than  the  electrolytic  interrupter. 


720  MKDICAL    KLKCTHiriTV    AND    HONTCiKN    HAYS 

Electrolytic  interrupters  (Fig.  457,  .ft)  depend  upon  a  principle 
enunciated  by  Spottiswood.  in  Is7(>,  that  when  a  current  of  electricity 
is  passed  through  a  liquid  and  one  of  the  metallic  electrodes  is  very 
small  t  he  surface  of  t  his  elect  rode  becomes  covered  with  a  laver  of  heated 
gas  or  vapor  which  interrupt  s  the  flow  of  the  current .  The  current  stop- 
ping, the  gas. or  vapor  is  dissipated  and  the  current  begins  to  flow  again 
with  the  same  re.-ult . 

These  depend  upon  the  thermal  effect  of  an  electric  current  when  it 
passes  through  a  liquid  path  with  a  very  small  cross-section.  The 
current  will  not  cause  excessive  heating  if  it  passes  from  one  large  metal 
plate  to  another  submerged  in  a  liquid  which  is  a  good  conductor  of 
electricity.  But  when  all  the  current  has  to  pass  through  the  small 
amount  of  liquid  represented  by  a  pin-hole  in  a  porcelain  jar  or  by  the 
fluid  in  contact  with  a  small  platinum  point,  the  resistance  of  a  1'ric- 
tional  character  becomes  so  great  that  the  liquid  not  only  boils,  but  is 
converted  into  a  mass  of  incandescent  gas.  This  effectually  destroys 
the  electric  contact  between  the  liquid  and  the  platinum  point  in  one 
type  of  interrupter;  or  between  the  two  bodies  of  liquid  in  the  other 
type.  In  either  case  the  good  conducting  path  afforded  by  the  dilute 
acid  liquid  is  broken  by  the  introduction  of  a  mass  of  gas  which  arrests 
the  whole  or  a  very  large1  part  of  the  current.  Xo  sooner  has  the  current 
ceased  to  How  than  the  incandescent  gas  disappears.  It  partly  collapses 
under  the  pressure  of  the  liquid  or  rises  to  the  surface  in  bubbles.  The 
flow  of  the  current  is  no  longer  obstructed,  but  its  reestablishment  is 
attended  by  the  formation  of  a  fresh  mass  of  incandescent  vapor  and  a 
new  arrest  of  the  current.  In  this  way  interruptions  are  produced  at 
regular  intervals  and  of  a  character  extremely  well  suited  to  .r-ray  and 
high-frequency  currents.  The  smaller  the  surface  of  platinum  exposed 
in  the  Wehnelt  and  the  smaller  the  holes  in  the  Caldwell-Sinion  inter- 
rupter1 the  more  rapid  the  interruptions  and  the  weaker  the  primary 
current,  and.  generally  speaking,  the  weaker  the  .r-ray  or  high-frequency 
current  excited  by  the  secondary  current. 

Electrolysis  takes  place  in  either  of  these  interrupters  with  the 
liberation  of  hydrogen  gas  at  t  he  negative  and  oxygen  gas  at  the  positive 
electrode,  and  there  is  some  liability  to  an  explosion  if  the  two  gases  are 
allowed  to  minule  in  a  confined  space  and  then  become  ignited  by  a 
at  some  loose  electric  contact.  The  result  is  more  disagreeable 
erous.  the  cover  of  the  box  being  thrown  a  few  inches  into  the 

•  dilute  acid  being  spattered  over  neighboring  objects.     There 
i-  of  absolutely  preventing  such  an  explosion,  but  ifs  occur- 

de  very  unlikely  by  certain  precautions.  The  inter- 
not  be  tighllv  closed.  If  it  is  covered  at  all.  there 
pie  opening  for  the  escape  of  hot  sulphurous  fumes 
cm-rent.  This  results  in  a  general  diffusion  of  the 
pin 'ii  in  the  air  of  the  room  instead  of  their  being 
•filtrated  and  explosive  form  in  a  small  space.  The 
ins  fume-  thus  allowed  to  escape  from  the  interrupter 

[well. 'in    \!neric:i,  mid  Simon,  in  Kun>|>e,  invented  (hi-  tvpe  of   interrupter 

•V-   in     i   '!:::  j  'hr.iLTin   bet  \\  ceil   t  he   t  \vo   h:dve-  i  if  , ;\     vessel    coll  t  M  i  I]  i  Iltr    the    elec- 

!  nd  I      Idwell  ;ils(i  figure  in   their   excellent    book   :in    interrupter   in 

/•     'I  i  he  communication  is  r<'<MiI:ite(l  by  a  c<mir  point    pushed   tlirouirh 

•  u'l'i    it'  r  or  |i—   di-t:ilice.      The  prc-ent    unthor  believes  thiit    lie  \v:is   the 
fir-t  to  p.ibli-h     Medic. d  Ilecord.  N'e\v  York.  October  L'l.    mo:!     :m; 

type  o]     ••,'-.;•,       •      •       imple-t   ;md    lie-t    form,    "  t  he    l'e;d\er    Int  i 

II I  like-     ]|i  i    e!  •:  ,  M  dit  V. 


THE    Z-RAY  721 

arc  disagreeable,  and  so  it  will  he  found  desirable  either  to  place  the 
interrupters  in  another  room  or  in  the  fireplace  and  cover  them  by  a 
wooden  cabinet  open  behind  to  allow  the  fumes  to  pass  up  the  chim- 
ney. Liquid  interrupters  may  be  placed  at  any  distance  from  the  x-ray 
coil,  but,  of  course,  it  is  necessary  to  have  them  where  they  will  be 
accessible  for  purposes  of  regulation  during  the  operation  of  the  appa- 
ratus. The  liquid  gradually  becomes  heated  and  after  it  has  reached  a 
certain  temperature  the  interruptions  become  irregular.  There  will  be 
a  scries  of  interruptions,  then  a  complete  pause  for  a  time,  and  then 
the  regular  interruptions.  The  .r-ray  flickers  in  consequence  and  be- 
comes less  effective.  A  stronger  current  must  be  turned  on  in  order 
to  secure  regular  interruptions  and  a  good  therapeutic  or  diagnostic 
effect,  bul  after  a  temperature  of  about  S()°  C.  is  reached  the  interrupter 
will  be  apt  not  to  work  at  all.  If  the  current  is  to  be  used  for  a  long- 
time, as  for  a  series  of  treatments  by  high-frequency  currents,  some 
arrangement  must  be  made  to  prevent  overheating  the  liquid.  The 
author  uses  five  independent  interrupters,  the  current  being  changed 
from  one  to  the  other  by  a  switch  right  at  the  .r-ray  coil,  although  they 
are  in  another  room.  Or  a  very  large  jar  can  be  used  holding  2  or 
3  gallons  of  liquid  which  will  heat  up  very  slowly.  Or  a  coil  of 
tubing  may  be  placed  in  the  liquid  and  a  current  of  cold  water  sent 
rhrough  it  to  keep  the  electrolyte  cool.  Having  several  interrupters 
accomplishes  the  result  very  well  and,  in  addition,  gives  one  a  great 
variation  in  quality  of  current,  and  the  wearing  out  or  the  accidental 
destruction  of  one  of  the  interrupters  leaves  the  other  interrupters  to 
fall  back  on.  In  the  author's  outfit  there  are  two  Caldwell-Simon 
interrupters  with  holes  of  different  sizes,  two  AYehnelt  interrupters  with 
platinum  points  of  different  thicknesses  and  with  a  different  electro- 
lyte in  each,  and  a  mechanic  interrupter  of  the  irhcrl  type1.  The  differ- 
ent Cakhvcll-Simon  interrupters  yield  a.  uniformly  interrupted  current 
of  from  4  to  10  amperes,  according  to  1  he  amount  of  resistance;  in  the 
rheostat  and  of  self-induction  in  the  primary  coil.  The  electrolyte  in 
these  two  interrupters  is  the  sam<  —  1  part  of  sulphuric  acid  and  (i  of 
water,  making  a  solution  with  a  specific  gravity  of  about  !.'_'.  The 
Wchnelt  interrupters  are  adjustable  as  to  the  length  of  the  platinum 
point  exposed  ami  transmit  a  uniformly  interrupted  current  of  from 
2  to  2~>  or  30  amperes  under  varying  conditions.  The  electrolyte  is 
sulphuric  acid  1  part  to  (i  parts  of  water.  A  substitute  may  be  1 
part  \valer  and  1  part  saturated  solution  of  Hochelle  salt  in  water,  a 
small  amount  of  sulphuric  acid  having  been  added.  The  Rochelle  salt 
alone  in  the  electrolyte  does  away  with  the  disagreeable  fumes,  but  its 
solution  is  not  nearly  as  good  a  conduct  or  of  electricity  as  dilute 
sulphuric  acid,  and  consequently  the  current  is  weakened  and  much 
more  heating  of  the  liquid  occurs;  and  it  becomes  quite  a  task  to  fre- 
quently (i pen  the  jar  and  pour  in  water  to  make  up  for  the  rapid  evapora- 
tion. The  plat  inum  in  each  is  a  cylindric  rod  about  f  mm.  in  thickness, 
and  a  greater  or  less  length  is  protruded  from  its  porcelain  sheath  by 
turning  an  insulated  knob  at  the  top  of  the  hard-rubber  tube  in  which 
it  is  held. 

\\ith  the  Caldwell-Simon  interniptei  the  polarity  of  the  current 
makes  no  difference;  but  with  the  \Yehnelt  interrupter  it  is  essential  that 
tlu>  positive  battery  wire  should  lead  to  the  platinum  point:  and  if  tin 
wrong  connect  ion  is  made.  1  he  interrupt  ions  are  irregular  and  the  sound 
is  rough  and  deep  and  the  platinum  i.-  much  more  rapidly  worn  away. 

4ti 


722 


MEDICAL    ELECTKICITY    AND    RONTGEN    RAYS 


The  cause  of  this  is  probablv  the  formation  of  a  sheath  of  hydrogen  gas 

upon  the  surface  of  the  platinum  when  it  is  connected  with  the  negative 
wire,  and  this  sheath  presents  great  resistance  to  the  electric  current. 
This  hydrogen  sheath  forms  a  barrier  even  when  a  large  portion  of  the 
platinum  is  exposed,  and  it  produces  more  continuous  resistance  than 
the  intermittent  disconnection  which  is  desired.  This  electrolytic- 
effect  is  separate  from  and  additional  to  the  thermal  effect  due  to  the 
Miiallness  of  the  liquid  conducting  path  at  that  point  and  the  conse- 
quent ohmic  resistance  or  friction. 

The  Wehnelt  interrupter  is  the  only  one  which  may  be  directly 
connected  with  and  will  partly  rectify  an  alternating  current.  It  works 
fairly  well.  but.  of  course,  the  platinum  point  has  an  undesirable  polarity 
half  of  the  time  and  wears  out  much  sooner  than  it  would  if  it  were 
connected  with  the  positive  wire  all  the  time. 

All  the  other  types  of  interrupter  for  induction-coils  require  that 
alternating  currents  shall  be  rectified  or  made  unidirectional  in  order 
that  they  can  be  used,  and  it  is  better  to  do  so  even  with  the  Wehnelt 
The  different  means  of  rectifying  the  current  will  be 
described  in  another  part  of  this  book. 
The  \YcJnuil  int< rntptcr  (Fig.  458) 
is  exactly  on  this  principle,  the  fluid 
being  sulphuric  acid  diluted  with  six 
1  hues  as  much  water,  the  large  electrode 
is  of  lead  and  the  small  one  is  of 
platinum  wire  enclosed  in  very  tough 
porcelain.  By  means  of  a  screw  ad- 
justment a  larger  or  smaller  amount 
of  the  platinum  may  be  caused  to 
project  beyond  the  porcelain  and  the 
electric  impulses  made  small  and  rapid 
if  little  of  the  platinum  is  exposed; 
and  heavier  and  less  rapid  if  a  greater 
length  is  exposed.  The  platinum  should 
always  be  connected  with  the  positive 
wire.  Such  an  interrupter  works  well 
with  the  direct  110-volt  current  and 
over  a  range  of  from  5  to  '.*>()  or  even 
10  amperes.  It  does  not  work  after 
the  fluid  becomes  overheated,  so  it  iq 
necessary  to  have  1  wo  or  more  if  the 
apparatus  is  used  continuously. 

C1fil//n(l/  or  Simon  Interrupter.  —  The  other  type  of  electrolytic  inter- 
rupter is  exemplified  hy  the  Caldwell  or  Simon  interrupter,  in  which 
then'  are  t  wo  large  lead  elect  rodes  dipping  into  dilute  sulphuric  acid,  the 
vessel  containing  which  is  divided  by  a  vertical  partition.  The  current 
through  pin-holes  in  this  partition  and  the  liquid  conductor  at 
narrow  plate.-,  of  course,  presents  great  resistance,  the  liquid  is 
i.  and  a  mass  of  vapor  cuts  off  the  current. 

e  most   practical   interrupter  of  this  type  is  a  beaker  interrupter 
lor  me  I iy   Wappler.  under  Caldwell's  [latent,  and  first   published 
Ye   in    tny  article  of  October  L' I.    IDO.'i   (Medical    llecord).      "This 
-  of  a   large  porcelain  jar,  partly  filled  with  dilute  sulphuric  acid 
i''h    i-   set    a    -mailer  jar  with   a   pin-hole    (three   holes  are   better) 
near  the  bottom.      One  conducting  wire  terminates  in  a  leaden 


i!itcrrii]>t(T 
.'{'.»    inch 


THE    X-RAY  723 

ring  resting  in  the  acid  in  the  outer  jar.  The  current  passes  through  the 
liquid  and  the  punctured  jar  to  the  leaden  plate  resting  in  the  acid  in 
the  inner  jar,  from  which  it  passes  by  a  conducting  wire  to  the  rheostat, 
and  then  through  the  primary  coil  and  thence  back  through  the1  negative 
wire  to  the  wall  socket." 

The  Wehnclt  interrupter  works  with  an  alternating  current,  but  not 
so  well,  and  with  more  rapid  wear  of  the  platinum  than  with  the  direct 
current.  The  platinum  really  ought  to  be  the  positive  pole,  and  with  an 
alternating  current,  of  course,  it  is  the  negative  pole  half  the  time. 
For  .r-ray  work  with  an  interrupter  of  the  Caldwell  type  the  alternating 
current  must  usually  first  be  changed  to  a  direct  current.  This  can  be 
done  by  means  of  a  motor  generator,  which  is  really  a  dynamo  run  by 
an  electric  motor,  or  of  a  mercury  arc  rectifier,  in  which  the  current 
passes  through  mercury  vapor  which  permits  the  passage  of  the  currents 
in  only  one  direction,  the  alternate  currents  being  suppressed.  Either  of 
these  means  is  effective'  and  would  be  chosen  for  an  office  outfit,  but 
for  an  outfit  at  a  patient's  home  the  simple  and  inexpensive  aluminum 
cell  in  which  the  fluid  is  a  0  per  cent,  solution  of  Rochelle  salt  or  of 
sodium  bicarbonate,  and  one  electrode  is  of  lead  and  the  other  of 
aluminum  or  carbon,  suppresses  the  alternate  current  perfectly  well 
for  treatment  and  for  all  but  the  heaviest  and  most  rapid  radiography. 

Aluminum  Cell  Electrolytic  Rectifier. — It  transmits  about  !)()  per  cent, 
of  the  currents  passing  in  one  direction  and  very  little  of  the  currents 
in  the  other  direction.  The  jar  should  be  capable  of  standing  a  certain 
amount  of  heat.  This  enables  one  to  use  the  YVehnelt  interrupter  with- 
out undue  consumption  of  the  platinum  point;  and  either  the  Wehnelt 
or  tin'  Caldwell  interrupter  with  good  functional  results  in  the  illumina- 
tion of  an  .r-ray  tube.  It  has  been  described  in  the  preceding  para- 
graph. 

Crookes's  Jilm  is  a  layer  -i^Vo  m('n  thick  which  forms  upon  the  lead 
surface  in  the  electrolytic  rectifier  and  acts  as  an  enormous  resistance1 
to  the  flow  of  current  in  the  wrong  direction. 

The  current  can  only  flow  freely  when  the  lead  electrode  is  con- 
nected with  the  positive  pole  of  the  source  of  electricity. 

The1  lead  in  the  electrolytic  rectifier  should,  therefore,  be  connected 
with  the  lead  in  the  Wehnelt  interrupter. 

(Vr/xxo/r.s-  rectifier  is  an  aluminum  cell  in  which  the  other  electrode  is 
of  iron  or  some  other  indifferent  metal.  When  the  aluminum  is  positive 
it  is  covered  by  bubbles  of  oxygen  and  a  layer  of  aluminum  hydrate, 
which  greatly  impedes  the  flow  of  the  current. 

HY//m//'.x  Rectifier  for  Alternating  Current*. — This  is  a  vacuum  tube 
in  which  the  cathode  is  made  of  platinum,  gas-carbon,  or  tantalum, 
and  c-onsequently  does  not  melt  when  heated  to  incandescence.  The 
cathode  is  coated  with  a  metallic  oxid.  The  rarefied  gas  offers  very 
little  resistance  to  the  passage  of  a  current  in  one  direction,  but  if  the 
current  is  reversed,  so  as  to  make  the  elect  rode  coated  with  oxid  the 
anode  instead  of  the  cathode,  the  current  is  almost  completely  arrested. 
The  effect  is  supposed  to  be  due  to  ionizution  of  the  rarefied  gas  in  the 
tube  by  the  incandescent  metallic  oxid. 

The  Mercury  Dip  Interrupter  (Fig.  4f>9). — One  of  the  wires  carrying 
the  primary  current  leads  into  the  bottom  of  a  glass  vessel  containing 
a  certain  amount  of  liquid  metallic  mercury.  The  other  wire  is  connected 
with  a  vertical  metal  rod  which  is  moved  up  and  down  by  a  small  elec- 
tric motor  and  ulternutelv  dips  into  and  is  withdrawn  from  contact 


724 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


with  the  mercury.  The  contact  is  thus  made  and  broken  and  the  alcohol 
which  covers  the  surface  of  the  mercury  prevents  the  formation  of  an 
arc.  The  interruptions  are  of  u'ood  character  and  may  be  regulated  as  to 
rapidity  by  varying  the  speed  of  the  motor. 


The  Mercury  Jet  Interrupter  (I'i£.  460). — One  of  the  primary  win 


ti-rmmates  in  the  liquid  mercurv.  the  other  in  a  sonos  of  metallic  sec- 


tions separated  by  insulated  spaces  which  form  a  horizontal  bolt  lining 


if  the  alcohol  reservoir  a  certain  distance  above  the  sur- 

A  M  elect  ric  mot  ( ir  causes  the  rr'volul  ion  of  a  vert  i- 

into   the  metallic  mercury.      V>v  centrifugal   force 

dt        '      iti  into  a  i  u  be  m  tin-  .-halt  and  1  hr<  >\vn  out  1  hrouidi 


THE    .C-RAY 


725 


11  horizontal  nozzle.  The  jet  of  mercury  pusses  through  tlic  alcohol  to 
conic  in  contact  with  one  of  the  metal  segments  and  complete  the;  metallic 
circuit.  At  the  next  part  of  the  revolution  the  mercury  jet  is  ;lirecte<l 
against  one  of  the  insulated  spaces  and  no  electric  current  flows.  The 
interruptions  may  be  made  faster  or  slower  by  varying  the  speed  of  the 
motor  and  arcing  is  prevented  by  submersion  below  the  surface  of  the 
alcohol. 

Kopiquet's  Mercury  Turbine  Interrupter. — The  new  features  of  this 
interrupter1  are  that  the  jet  of  mercury  does  not  form  one  of  the  elec- 
trodes, but  simply  a  conducting  bridge  between  them,  and  that  the 
contact  is  broken  partly  by  the  interposition  of  a  non-conducting  barrier. 
The  complete  apparatus  is  shown  in 
Fig.  401.  There  is  a  small  "lectric 
motor  which  is  run  by  the  110-  or 
2'_>0-volt  direct  current  and  the  speed 
of  which  can  be  regulated  by  means 
•jf  a  rheostat.  A  leather  belt  con- 
nects this  motor  with  the  vertical 
axis  of  the  interrupter  and  causes  it 
to  revolve.  Two  conducting  wires, 
one  from  the  wall-socket  of  the 
110-  or  220-volt  electric-light  cir- 
cuit and  the  other  leading  to  one  ter- 

,      ,.     .  .  ''    .      .         .  ]•!"•   4(;i.»—Ropiqupts  mercury  turbine 

minalot  the  primary  of  an  induct  ion-  mti-rrupter. 

coil,    are  fastened  to  vertical  metal 

rods  which  can  be  raised  or  lowered  "by  insulated  screws.     These  ] 


of 


but  do  not   reach  the  level  of 


the  s  pounds  of  mercury  in  the  bottom  of  the  interrupter.  At  their 
lower  extremity  these  rods  expand  into  triangular  -nirfaces,  large  above 
and  pointed  below.  The  lower  part  of  the  revolving  axis  is  hollow 
and  contains  a  pump,  on  the  principle  of  the  turbine  or  a  sort  of  cork- 
screw motion,  which  draws  the  mercury  up  through  the  hollow  shaft  of 
the  vertical  axis  and  out  through  two  horizontal  tubes.  These  two 
tubes  also  revolve  with  the  vertical  axis  and  centrifugal  force  is  added 
to  that  produced  by  the  pump.  Two  jets  of  mercury  are  thrown  out 
through  the  alcohol  in  a  horizontal  direction  and  as  the  axis  revolves 
ihe>e  jets  also  make  complete  revolutions.  In  a  certain  position  the 
two  jets  impinge  upon  the  two  metal  electrodes  and  form  a  complete 
conducting  path  of  metallic  mercury  between  the  two  electrodes.  As 
the  jets  continue  to  revolve,  they  pass  the  point  at  which  they  are  in 
contact  with  the  metal  electrodes  and  the  circuit  is  thereby  broken, 
but  besides  this  they  strike  against  hard-rubber  or  other  insulating 
barriers.  These  are  placed  obliquely  and  as  the  mercury  strikes 
one  of  them  it,  of  course,  is  prevented  from  going  out  as  far  as  the  metal 
electrode.  The  breaking  of  the  electric  contact  is  rendered  much  more 
complete  and  sudden  than  when  the  sole  dependence  is  placed  upon  the 
circular  sweep  of  the  mercurv  jet.  lu  the  latter  case  the  break  spark  is 
of  considerable  volume  because  the  mercury  docs  not  get  far  enough 
away  from  the  metal  electrode  for  quite  an  appreciable  length  of  time 
and  there  is  also  a  perfectly  straight  path  between  them.  "\Yith  this  new 
improvement  the  mercury  jet  is  instantly  stopped  at  a  considerable 
distance  from  the  metallic  electrode  and  the  formation  of  an  arc  is 
1  L'uolishc.'d  March  10,  I'lni.i,  Archive-  dVh'Ctricite  Mrdirale,  Bordeaux,  l-'ranc-j. 


726  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

further  prevented  by  the  oblique  direction  of  the  hard-rubber  barrier, 
As  the  mercury  jet  passes  over  this  surface  the  break  spark  would  have 
to  turn  quite  an  acute  angle  in  order  to  pass  from  the  electrode  to  the 
mercury.  The  rupture  is  so  complete  that  no  condenser  is  required  to 
suppress  the  break  spark  for  safety  to  the  apparatus  or  for  securing  a 
good  quality  of  induced  secondary  current.  This  interrupter  also 
enables  one  to  dispense  with  a  rheostat  or  a  volt  controller,  because  the 
strength  of  the  current  can  be  regulated  from  1  to  1">  amperes  by  ad- 
justment of  the  interrupter  alone.  The  way  in  which  the  current 
strength  is  increased  is  by  lowering  the  metal  electrodes  and  thus  pre- 
senting a  wider  surface  for  the  mercury  jet  to  sweep  across  and  increasing 
the  fraction  of  each  revolution,  during  which  the  current  flows.  The 
average  strength  of  the  current  is  what  is  meant  when  we  say  that  a 
primary  current  of  a  certain  number  of  amperes  is  used.  This  is  de- 
termined by  the  proportion  between  the  time  that  the  current  is  flowing 
and  the  time  that  it  is  interrupted.  There  is  a  very  small  total  resist- 
ance in  the  circuit,  1  or  2  ohms  resistance  from  friction  in  the  primary 
wire  and  not  much  more  additional  resistance  from  self-induction  and 
practically  no  resistance  in  passing  through  the  conducting  jet  of  mer- 
cury in  the  interrupter.  At  any  time  that  the  current  is  flowing  it 
may  encounter  a  total  resistance  of  only  2,  o,  or  4  ohms,  and,  according 
to  Ohm's  law.  the  current  strength  would  be  from  50  to  20  amperes 
with  100  volts  or  100  to  40  amperes  with  200  volts.  The  strength  of 
the  current  in  amperes  is  equal  to  the  number  of  volts  divided  by  the 
resistance.  Such  a  strength  may  actually  flow  for  fractional  periods 
of  time  during  the  passage  of  the  current  through  this  interrupter,  but 
the  periods  of  time  during  which  there1  is  no  current  at  all  brings  the 
average  down  to  a  much  smaller  number  of  amperes.  This  is  regulated 
at  somewhere  between  1  and  15  amperes  for  most  therapeutic  purposes. 
There  is  no  possibility  of  the  interrupter  stopping  in  such  a  position  as 
to  produce  a  stationary  mercury  bridge  across  the  space  between  the 
metallic  electrodes  and  permit  a  continuous  flow  of  the  current  which, 
of  course,  would  be  destructive  because  of  its  strength.  The  mercury 
bridge  is  only  formed  when  the  axis  is  in  rapid  rotation;  when  the  shaft 
is  stationary  there  is  no  turbine  pump  force  at  work  to  raise  the  mercury 
in  the  hollow  axis  and  no  centrifugal  force  to  impel  it  out  horizontally 
and  cause  it  to  strike  against  the  two  electrodes.  The  amperemeter 
which  measures  the  strength  of  the  primary  current  indicates  the 
average  number  of  amperes.  Kven  if  the  instrument  were  made 
with  a  needle  which  would  pass  back  and  forth  from  the  zero  to  the 
.">()  or  ]()()  ampere  mark  on  the  dial  scores  ot  times  a  second  it  would  be 
useless.  The  eye  could  not  follow  its  motions,  and  even  if  it  could  we 
should  not  obtain  the  information  that  we  require. 

\n  obturator  may  be  adjusted  to  prevent  the  two  opposite  mercury 
jets  from  strikinij.-  the  metal  electrodes  in  one  position  while  they  still 
continue  to  do  so  when  in  the  opposite  position.  This  permits  of  the 
passage  ot  the  current  onlv  once  for  each  complete  revolution  of  the 
a\is  instead  of  twice,  as  is  the  case  when  the  obturator  is  not  used. 
I.;i''!i  tiny  traction  of  a  second  that  the  current  (lows  produces  practi- 

•  the  same  effect  upon  an  .r-ray  tube,  whether  this  occurs  once 
or  twice  for  each  revolution  of  the  axis.  The  visible  effect  and  the 
Huoro-cn  ill  I,,'  about  the  same  in  both  cases.  The  obturator 

and  the  :••  ite  of  current  How  may  be  used  for  fluoroscopic  ex- 


THE    X-RAY  727 

animations  and  will  avoid  wear  and  tear  upon  the  x-ray  tube  and 
reduce  by  one-half  the  effect  upon  the  patient.  It  will  be  found  best 
to  dispense  with  the  obturator  and  thus  secure  the  double  rate  of 
current  How  for  making  radiographs,  the  same  quantity  of  radiation 
being  produced  in  half  the  time.  Kither  the  single  or  the  double  rate 
may  be  used  for  x-ray  treatments,  due  allowance  being  made  for  the 
difference  in  the  amount  of  radiance.  This  may  be  made  clearer  by  an 
example  in  ordinary  photography.  If  we  have  a  100-candle-power  arc 
light  which  is  only  turned  on  for  one-sixth  of  every  small  fraction  of  a 
second,  it  will  illuminate  the  interior  of  the  room  to  the  full  1000-candle- 
power  extent  each  time,  and  the  persistence  of  the  effect  upon  the  retina 
of  the  eye  may  enable  one  to  see  objects  practically  the  same  as  if  there 
were  two  such  periods  of  illumination  for  one-sixth  of  the  time  or  a 
total  of  one-third  of  each  small  fraction  of  a  second.  The  effect  regis- 
tered upon  a  photographic  plate  or  its  physiologic  effect  upon  plants  or 
animals  would  be  twice  as  great  with  the  double  as  with  the  single  rate 
of  exposure. 

Somewhat  similar  variations  in  the  current  may  be  obtained  with 
the  \Vehnelt  interrupter  by  having  different  sixes  of  platinum  rods  and 
means  for  regulating  the  length  of  the  platinum  rod  exposed;  by  using 
a  variety  of  electrolytes  of  greater  or  less  conductivity  and  by  the  use 
of  a  rheostat. 

Ropiquet's  interrupter  supplies  the  desiderata  of  a  mathematic  regu- 
lation of  the  average  strength  of  the  current ;  a  uniform  strength  of  current 
while  the  contact  is  made  and  a  very  sharp  and  perfect  break;  the  regula- 
tion of  the  number  of  contacts  per  second  and  of  the  relation  in  time 
between  the  duration  of  each  contact  and  the  interval  between  them. 

Kither  a  rheostat  or  a  volt  controller  may  be  used  with  this  inter- 
rupter and  will  supply  useful  though  not  essential  modifications  of  the 
current.  It  will  enable  us,  for  instance,  to  modify  the  strength  of  the 
current  without  changing  the  duration  of  each  contact,  as  is  done  when 
the  strength  is  regulated  by  adjustment  of  the  electrodes  in  the  inter- 
rupter itself. 

Care  of  Mcrcnnj  Interrupters. — There  is  a  small  amount  of  sparking 
as  the  contact  is  broken  in  all  these  mechanic  interrupters,  and  this 
corrodes  the  metal  surfaces  and  the  alcohol  becomes  muddy  and  has  to 
be  changed.  A  scum  which  forms  upon  the  surface  of  t  he  mercury  must 
be  washed  off  occasionally,  so  that  a  certain  amount  of  expert  care  is 
required  at  short  intervals.  Fortunately,  the  motor  is  not  likely  to  get 
out  of  order  frequently.  The  alcohol  does  not  often  take  fire  from  the 
sparks  at  t  he  making  and  breaking  of  the  contacts  because  the  latter  are 
below  the  surface  and  no  free  oxygen  is  present  to  combine  with  the 
alcohol.  But  when  this  does  happen  there  is  danger  of  fire.  These 
mechanic  interrupters  are  excellent  for  x-ray  and  other  extremely  heavv 
elect  rot  herapeut  ic  work,  but  they  are  more  expensive  and  more;  com- 
plicated than  electrolytic  interrupters. 

77/r  ( 'oiri  in  iitittnr  T/ip<  of  I  ntrrrii  ptcr. — One  of  the  best  of  these 
is  the  Johnston  interrupter,  made  by  the  \Vestinghouse  Company.  It 
is  an  electric  motor  whose  shaft  dips  obliquely  below  the  surface  of 
alcohol  in  a  metallic  reservoir,  and  upon  this  shaft  is  mounted  a  series 
ot  metal  contacts  alternating  with  insulated  spaces  of  mica  or  indurated 
fiber.  As  this  revolves,  a  stationary  metal  brush  comes  in  contact  first 
with  a  metal  section,  making  the  current,  and  then  with  an  insulating 


<2N  MKIMCAL    KLKCTHICITY    AND    RONTGEN    KAYS 

section   breaking   the   current.     Submersion   below    the   sui'face  of  the 
alcohol  prevents  the  format  ion  of  an  arc  as  the  current  is  broken. 

The  Conlrcniulin  itihrrnphr  (Fig.  402),  made  by  (laitfo,  of  Paris, 
i<  another  of  the  commutator  typo.  A  small  electric  motor  causes  the 
revolution  of  a  disk  of  insulating  material  in  which  are  inlaid  strips  of 
metal  as  in  Fig.  402.  Four  strips  of  metal  separated  by  portions  of  the 
insulating  substance  form  the  rim  of  the  disk  and  separate  metal  strips 
connect  the  opposite  strips;  so  that  there  are  two  independent  pairs  of 
metallic  conductors  separated  by  non-conducting  sections.  The  cur- 
rent passes  through  metallic  brushes  which  are  at  opposite  sides  of  the 
revolving  di-k  and  press  upon  its  periphery.  At  times  the  brushes  are 
pres.-im:  airamst  the  surfaces  of  one  pair  of  metal  strips  and.  of  course, 
the  current  i>  transmitted.  At  other  times  the  brushes  are  in  contact 
with  i  he  insulating  material  and  then  the  current  ceases  to  flow.  Then 
the  disk  revolving  to  another  position  brings  the  other  pair  of  metal 
.-trips  in  contact  with  the  brushes,  completes  the  electric  connection. 
and  allows  the  current  to  How  again.  The  number  of  interruptions  per 
second  is  varied  according  to  the  speed  of  the  motor,  and  then  again  the 
apparatus  may  be  made  with  more  than  two  pairs  of  conducting  strips. 
and  this  will  increase  the  number  of  interruptions  produced  by  each 
revolution.  This  is  a  really  excellent 

type    of    interrupter   for   currents   of  p 

anv    moderate   strength.       Its    action 


i-  positive  each  make  and  break  beinir  perfect  without  any  ineffectual 
contacts,  as  with  a  vibrating  interrupter,  but  arcing  i-  liable  to  occur 
\\i;h  the  heaviest  r-ray  currents  and  it  should  be  submerged  in  alcohol 
if  U-cd  for  that  ]  nil')  >ose. 

( '/iri'<  nfii  r's  *  nil  rr  n  jilt  r  i  Fig.  40)-$)  is  of  the  atonic  or  <i/><  r/txlir  tvpe. 
The  hammer  \\lnch  is  to  be  attracted  bv  the  magnetized  mm  core  of 
the  primary  coil  i-  upon  a  ri^id  stem  which  is  drawn  away  from  the  core 
11-1  the  point  of  a  screw  bv  the  traction  o|  a  spiral  spring. 
1 ::  no  p.  >-ii  in  1 1  doe-  i  he  ha  in  n  HT  or  its  -lei  M  t  ran -mil  the  current.  \\  hen 
the  current  i-  turned  on  the  mm  core  becomes  an  electromagnet  and 
at  t  ra''t  s  the  hammer,  v.  Inch,  moving  forward,  presses  against  a  straight 
spring  v.hich  ha-  been  t  ran-nut  t  mi:  the  current,  but  now  has  its  end 
pu-hei]  from  the  point  of  contact.  Tin-  stops  the  current;  the 

ha  n  iiner  i<  ilra  \\  n  back  to  it  -  original  posit  ion  by  the  act  ion  of  1  he  spiral 
sprmtr:  the  con;  aci -bearing  -prnm'  iroes  back  to  its  po.-ition.  where  an 
electric  contact  i-  a^ain  made  between  a  platinum  surface  on  the  spring 


THE    .r-RAY  729 

and  the  platinum  point  of  a  screw  placed  there.  The  current  flows 
again  ami  the  same  interruption  is  produced.  The  limits  of  the  use- 
fulness of  such  an  interrupter  for  .r-ray  work  arc  an  s-inch  coil  with  a 
current  of  10  volts  and  an  average  of  (i  or  7  a mperes  and  .'!'_'  ml errupt  ions 
per  second;  or  1  volts  and  an  average  of  10  amperes  and  '.'>  interruptions 
a  second.  \\  ith  the  first  speed  of  interruption  good  hut  not  the  most 
rapid  .r-ray  work  can  be  done,  lor  instance,  with  a  battery  ol  0  storage- 
cells  giving  1  -  volts  a  radiograph  of  the  pelvis  can  be  made  in  H\  min- 
utes. 1  Hull-frequency  apparatus  also  works  well  with  such  a  current. 
A  condenser  is  necessarv  with  a  coil  supplied  with  such  an  interrupter. 
The  rapiditv  of  the  interruptions  is  partly  self-regulating;  depending 
upon  the  strength  of  the  electromagnet  and  hence  upon  the  strength 
of  the  current  and  the  amount  ot  self-induction  in  the  primary  coil;  and 
partlv  adjustable  by  changing  the  tension  of  the  spiral  spring  connected 
with  the  hammer,  and  by  turning  the  screw  against  which  the  hammer 
presses  when  at  rest.  Advancing  thi>  point  makes  a  shorter  excursion 
or  to-and-fro  path  for  the  hammer  and  makes  the  interruptions  more 
rapid.  The  adjustment  of  the  screw  which  bears  the  point  of  contact 
is  not  particularly  for  the  regulation  of  -peed,  although  it  may  affect 
the  speed  incident  allv.  and  the  other  speed  adjustments  may  have  to 
be  altered  to  correct  the  change  made  by  it.  This  screw  is  intended 
to  be  turned  when  the  contacts  seem  to  be  imperfect. 

The  Carpentier  interrupter,  like  all  others  of  the  vibrating  type, 
must  be  used  in  the  air.  and  is  limited  to  a  strength  of  current  which 
will  not  produce  an  arc  between  the  points  of  contact  when  thev  are 
separated.  It  cannot  be  submerged  m  anv  liquid.  To  use  such  an 
interrupter  with  the  110-  or  220-volt  current  a  motor  generator  or 
rotary  transformer  would  be  required  giving  a  current  of  is  volts  and 
s  amperes.  A  voltaic  battery  of  0  or  s  large  bichromate  of  potash 
cells  may  be  used. 

A  storage-battery  of  0  or  S  cells  would  also  operate  an  .r-ray  coil 
provided  with  a  Carpentier  interrupter. 

A  condenser  is  a  necessity  with  this  type  of  interrupter,  and  an  ad- 
ju.-table  resistance  or  rheostat  affords  the  most  convenient  means  of 
regulating  the  strength  of  the  current. 

Other  interrupters  are  described  at  p.  854,  in  the  section  on  Radiog- 
raphy. 

REGULATION  OF  THE  PRIMARY  CURRENT 

The  strength  of  the  current  varies  directly  and  the  rapidity  of  the 
interruptions  inversely  as  the  sixe  of  the  pin-holes  in  the  Caldwell 
interrupter,  and  it  is  necessary  to  have  a  rheostat  to  reduce  the  strength 
of  the  current  in  cases  in  which  the  full  current  transmitted  by  the 
mt errupt er  is  not  required. 

The  greater  length  of  platinum  point  exposed  in  the  YVehnelt  inter- 
rupter the  heavier  current  is  transmitted.  Other  interrupters  also 
regulate  t  he  current  st  rengt  h  to  a  cert  a  in  extent .  It  is  always  desirable, 
however,  to  have  a  separate  regulator,  called  a  rheostat. 

The  Rheostat. — Two  general  types  of  rheostat  are  suitable  for. r-ray 
apparatus.  (  )ne  is  made  of  rather  fine  iron  wire  wound  upon  a  long  insu- 
lated cylinder,  a  rack  and  pinion  movement  chanties  the  point  of  contact 
to  different  turns  of  the  iron  wire.  The  current  in  this  way  may  be 
allowed  to  pass  with  scarcely  any  resistance  or  gradually  the  whole 


730  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

resistance  of  the  25  yards  of  iron  wire  may  be  turned  on.  This  type 
may  be  called  a  drum  rheostat.  The  other  type  consists  of  an  insulated 
iron  plate  across  the  back  of  which  an-  fastened  1")  strips  of  sheet  iron 
or  of  (ierman  >ilver.  each  several  feet  long,  but  crimped  so  as  to  be 
fastened  between  binding-posts,  only  !)  or  10  inches  apart.  With  the 
insulated  handle  turned  all  the  way  over  the  contact  is  made  between 
points  which  permit  the  current  to  pass  with  more  or  less  resistance. 

Khcuxtdt  i  >•('/  //•(///  tin  Author' m  l~-inch  Induction-coil. — The  rheostat 
has  a  number  of  different  steps.  Xearesi  the  short-circuit  position  or 
the  position  where  no  rheostat  resistance  is  introduced  there  is  a  step 
with  a  resistance  of  0.4  ohms.  Following  this  there  are  three  other 
steps  of  0.4  ohms  each:  2  of  0.5  ohms  each;  2  of  0.7  ohms  each:  2  of  1 
ohm  each:  2  ot  1.75  ohms  each,  and,  finally.  2  of  2  ohms  each. 

For  radiograph}'  with  a  Wehnolt  interrupter  the  author  cuts  out  all 
the  resistance  from  the  rheostat;  but  with  the  Wapplor  mechanic  inter- 
rupter he  employs  a  rheostat  resistance  of  about  (i  ohms. 

For  radiotherapy  0  or  S  ohms  rheostat  resistance  are  employed  with 
the  Wehnolt  interrupter  and  12  or  14  with  the  Wapplor  mechanic  inter- 
rupter. 

The  rheostat  resistance'  required  for  high-frequency  currents  is 
usually  Hi  ohms  if  the  Wapplor  mechanic  interrupter  is  used,  or  12  or  14 
ohms  with  the  Wehnolt  interrupter. 

Turning  the  handle  back,  the  current  must  pass  through  one  or  more 
lengths  of  crimped  iron,  and  is  reduced  in  strength  by  the  resistance 
encountered.  The  further  the  handle  is  turned  in  this  direction  the 
irreator  is  the  resistance  and  the  less  the  strength  of  the  current  which  is 
allowed  to  pass. 

Fither  kind  of  rheostat,  depending  on  the  fact  that  iron  is  a  poor 
conductor  of  electricity,  becomes  heated  in  consequence  of  the  friction 
encountered  by  the  current  in  passing  through  it.  The  greater  the 
resistance  introduced  the  greater  the  heat,  but  this  does  no  harm,  pro- 
vided the  capacity  of  the  rheostat  is  not  exceeded.  The  gridiron  rheo- 
stat i-  made  to  carry  the  heaviest  current.-. 

The  primary  coil  is  of  heavy,  well  insulated  copper  wire  (Xo.  12, 
B.  W.  S.i.  and  is  wound  around  a  core  consisting  of  many  rods  of  soft 
iron  (Xo.  :>0.  B.  W.  S.).  The  iron  core  is  about  2  inches  in  diameter 
for  a  12-inch  coil.  It  become.-  a  powerful  electromagnet  and  adds  very 
much  to  the  amount  of  induction.  The  wire  should  be  wound  like 
thread  on  a  -pool,  all  the  turns  being  in  the  same  direction,  but  in  two 
or  three  01-  more  layers,  depending  on  iho  si/o  of  the  coil,  and  it  should 
be  provided  with  several  binding-posts,  by  mean.-  ot  which  the  conduct- 
inLi  curd-  may  be  attached  in  such  a  way  as  to  vary  the  path  that  the 
ciHTenl  must  pa--  through.  Thus  the  current  mav  be  made  to  pass 
through  the  entire  length  of  the  wire  in  the  primary  coil  as  a  single 
continuous  skein,  or  it  may  pass  through  all  the  layers  but  one  or  two. 
or  perhaps  onlv  through  one  layer.  In  a  portable  outfit  designed  by 
'  'al<  I  well  and  made  by  \  an  I  lout  en  and  Ten  Broeck .  the  variation  is  onlv 
from  one  continuous  skein  to  four  \ 
produce  v.  hat  i.-  known  as  variable  si 
n  will  be  -een  later  that  the  mamp 
import  ance  in  rai  liography. 

Sell         •  m  from  a  i  lirect  or  coi 

onh  iviii'_r  an  iron  core. 


THE    X-RAY  731 

According  to  Alltcrs  Schoenherg,  the  primary  coil  fora  50-cm.  coil, 
that  is.  one  designed  to  give  a  heavy  discharge  across  a  space  of  50  fin. 
(17  inches),  should  consist  of  six  layers,  giving  a  variation  of  from  1(30  to 
1000  turns. 

The  vibrating  interrupter  of  an  .r-ray  coil  may  be  placed  in  air 
compressed  to  2  or  3  atmospheric  pressures  and  this  will  prevent 
arcing,  according  to  Januszkiewicz  (IMiys.  Zeit..  \o.  12,  I'.)OG). 

A  condenser  is  required  for  an  .r-ray  coil  when  any  kind  of  mechanic 
interrupter  is  used.  It  is  made  up  of  sheets  of  tin-foil  about  s  inches 
square  separated  bv  paraffin  paper  or  mica.  It  is  necessary  that  the 
insulation  between  the  two  sets  of  50  to  100  sheets  should  be  perfect, 
because  otherwise  the  primary  current  would  be  short  circuited  and 
would  flow  through  the  condenser  instead  of  through  the  primary 
coil.  To  secure  this  perfect  insulation  it  is  best  to  boil  the  condenser  in 
melted  paraffin  until  every  bubble  of  air  escapes. 

The  secondary  coil  is  built  up  around  a  hollow  cylinder  of  mica 
acting  as  an  insulator,  into  which  the  primary  coil  may  be  slipped  and 
which  has  walls  from  }  to  \  inch  thick,  depending  upon  the  sixe  of  the 
coil.  The  copper  wire  is  as  fine  as  a  hair  and  is  all  wrapped  with  thread. 
It  is  coated  with  melted  paraffin  as  it  is  wound  on  bobbins,  each  of 
which  contains  thousands  of  turns.  In  the  author's  S-inch  portable 
coil  there  are  12  pounds  of  No.  34  wire.  The  bobbins  are  in  the  form 
of  thin  circular  disks  with  a  hole  in  the  center.  They  are  all  strung 
on  a  mica  cylinder  and  are  separated  from  each  other  by  disks  of  hard 
rubber.  The  number  of  these  bobbins  may  vary  from  S  to  SO,  depend- 
ing upon  the  sixe  of  the  coil  and  upon  the  labor  that  the  manufacturer 
puts  into  it.  The  whole  coil  is  sometimes  kept  permanently  immersed 
in  oil  as  an  insulator,  but  the  more  usual  practice  is  to  pour  melted 
paraffin  over  it,  which  on  cooling  forms  one  solid  mass.  The  secondary 
coil  terminates  in  two  brass  binding-posts  to  which  are  attached  the 
variable  spark-gaps  leading  to  the  conducting  cords  of  the  x-ray  tube, 
and,  what  is  very  important,  rods  for  determining  the  spark  resistance 
of  the  tube. 

The  Sprintremeter. — This  consists  of  two  rods  attached  to  the  two 
poles  of  the  coil,  and  if  they  are  approximated  while  the  .r-ray  tube  is  in 
operation  the  distance  at  which  a  spark  will  leap  between  them  is  called 
the  sparking  length  of  the  tube  and  indicates  its  resistance  to  the  passage 
of  the  current.  This  is  one  of  the  elements  in  determining  the  condition 
of  the  vacuum  in  the  tube  and  its  fitness  for  various  radiographic  and 
therapeut  ic  purposes. 

The  author's  office  .r-ray  apparatus  consists  of  a  12-inch  coil  with 
amperemeter  on  the  primarv  wire,  two  Wehnelt  and  two  modified  ('aid- 
well  interrupters,  a  \\appler  wheel  interrupter,  gridiron  rheostat, 
primary  coil  with  variable  self-inductance,  secondary  coil  with  the 
author's  adjustable  spark-gaps,  combined  with  a  d'Arsonval  appara- 
tus tor  high-frequency  currents,  which  is  connected  with  the  coil  by 
simply  t  urn  ing  t  wo  brass  rods  into  contact  wit  h  the  poles  of  the  secondary 

Cl  111. 

Portable  x-ray  outfits  for  use  on  the  electric  light  circuit  should  not 
contain  any  single  piece  weighing  more  than  50  pounds.  The  author's 
own  outfit  for  use  with  110  volts  direct  current  consists  of  a  secondary 
coil  measuring  S.\  X  S*,  X  17  inches  and  weighing  50  pounds,  a  separate 
primary  coil  with  three  different  windings  weighing  17  pounds,  a  Wehnelt 


<••>-  MKD1CAL    KI.K<  TKiriTY    AM)    H()NT(iEN    HAYS 

interrupter  in  a  box  measuring  S  X  S  X  '•  inches,  with  an  additional  3 
inches  for  its  screw  adjust ment  of  the  platinum  point  and  weighing  13 
pounds  without  the  fluid,  which  is  added  at  the  patient's  home,  and  a 
carrying  case  for  two  ./'-rays  tubes  and  four  .r-ray  plates  in  envelopes. 
This  case  weighs  111  pounds  and  measures  S.\  X  bV>  X  20  inches.  The 
tubes  are  clamped,  inside  and  the  plates  may  lie  any  size  up  to  1-4  X  17 
inches,  and  are  in  an  entirely  separate  compartment.  This  carrying 
case  was  made  for  me  l>y  Mr.  Percy  Russell,  of  New  York.  The  tube 
holder  is  fastened  to  an  upright  which  screws  into  one  pole  of  the  coil. 
The  use  of  the  \\ehnelt  interrupter  enables  us  to  dispense  with  a  rheo- 
stat and  an  amperemeter.  Tests  made  at  the  oflice  show  that  when 
the  apparatus  is  set  up  complete  with  a  oO-cm.  heavy  target  Miiller 
tube  and  connected  with  the  1  10-volt  direct  current  and  the  point  of 
platinum,  which  is  of  '2  mm.  cross-section,  is  just  flush  with  the  porce- 
lain the  current  is  \\  amperes,  regardless  of  what  primary  winding  or 


hal    'I'-Li!'*1'-  'it   vacuum   may  be  used.      K.-trh   complete  turn  of  the  in- 

-ulated  knob  which  regulates  the  \Yelmelt   adds   1   mm.  to  the  length  of 

|ioiii1    exposed,    and    by    I'eference    to    a    written    table    the 

ra'_;e  i,\   the  curi'eiit  with  various  primai'v  \\'indiim~.-  and  with  tubes 

nl   ditlefent    ile^rees  ot    vacinui)   ina\'  be  read  at    a   U'laiice. 


Tiii.-    i-    svitli    a     r-incii    tung.-ten     target     tube    with    medium    high 
vacuum. 


THE    X-RAY 


733 


With  the  same  tube,  but  with  the  lowest  vacuum  suitable  for  .r-ray 
work  and  with  the  same  conditions  as  to  primary  winding  and  interrup- 
ter, the  amperage  is  found  to  be  about  one-fifth  "Tenter  than  the  figures 
given  above.  At  a  patient's  house  or  hotel  it  will  be  found  wise  not  to 
employ  more  than  about  12  amperes  for  the  thicker  parts  of  the  body, 
and  (i  or !)  amperes  with  Xo.  3  winding  would  be  excellent  for  radiograph- 
ing the  extremities,  and  even  a  weaker  current  would  be  used  for  treat- 
ment . 

If  there  is  no  electricity  in  the  house  to  which  you  are  going  the 
current  may  be  supplied  from  an  electric  automobile,  or  the  above  outfit 


Portable  .r-rav  and 


i -frequency  apparatus  of  t  he  Tola  type  (Hyfrex  Xo.  1). 


can  be  modified  by  omitting  the  Wehnelt  interrupter  and  taking  one  or 
more  storage-battery  ceils  and  a  vibrating  interrupter  and  condenser. 

The  Wappler  mechanical  interrupter  and  a  rheostat  make  a  desirable 
substitute  for  the  Wehnelt  interrupter  in  a  portable  outfit. 

A  desirable  portable  ilcftric  <i<  >/<  rotor  I'm'  .r-rni/  m >/•/,•  consists  in  part 
of  the  I  )elco  light  set.  comprising  a  gasoline  engine  and  a  dynamo  which 
is  to  be  specially  constructed  so  as  to  give  an  alternating  current,  an- 
other unit  comprising  a  high  tension  transformer  for  .r-ray  and  a  low 
tension  transformer  for  (he  filament  current  of  a  Coolidge  tube.  This 
was  used  by  the  [' .  S.  Army  in  the  World  War. 

Portabh    x-Ii(i\i  Outfit  of  thi    Tt*!<i  Hiyfi-fri'tjuencij  TI//H   i  Fig.  4(i.V. — 


"34 


MEDICAL    KLKCTRlflTY     AM)    KONTCKN     HAYS 


An  apparatus  of  the  above  type1  when  closed  measure's  22  inches  in 
length.  12  inches  in  width,  and  t>  inches  in  thickness.  It  weighs  38 
pounds  complete.  The1  discharge1  is  an  alternating  one  and,  therefore, 
does  not  exe-ite  an  ordinary  .r-ray  tube1  as  we'll  as  if  a  KuhmkoriT  coil 
we're1  useel.  A  high-fivqiiency  .r-ray  tube1  (Fig.  4(it'>),  however,  give1? 
an  exevlle-nt  radiance,  suitable  for  all  therapeutie-  purposes  and  for  the 
lighter  forms  of  radiography.  The  apparatus  is  made  for  either  the 
alternating  or  direct  e-urrent. 


Hi:.  -liiO. — Minn-frequency  .r-ray  tube  for  use  when  the  secondary  current   has  an  altcr- 


Voltage  of  Different  Secondary  Spark  Lengths. —  Walter1  reports 
the  following  voltages  with  alternating  currents,  induction  spark 
length,  in  the  open  air: 

Maximum  Voltage. 

10  fin.  20  rni.  30  cm.  40  cm.  5()cm. 

t)4,()00          IDS, (MM)          14S.OOO          ItiS.(MM)         21f'»,()()0 

My  own  observations  with  the  Cabot  direct  current,  high  potential 
converter  were  made2with  a  gap  between  two  loops  of  wire,  (laps  of  1 
and  2  cm.  showed  less  than  10  kilovolts,  the  first  graduation  on  my 
voltmeter,  (laps  of  3  and  4  cm.  showed  about  10  kilovolts,  and  gaps  of 
.")  and  ('•  <«m.  15  and  40  kilovolts.  (laps  of  7,  8,  9,  and  10  cm.  did  not 
permit  a  spark  to  pass  until  the  voltage1  had  been  raised  to  (>4,  70,  72,  and 
*0  kilovolts.  In  every  case  there  was  a  drop  to  less  than  one-half  the 
Voltaire  durinir  the  passage  of  the  spark. 

Spark  lengths  with  a  transformer,  measured  between  moderately 
sharp  points,  are  usually  about  as  follows: 


. 

Volt- 

Kiovolt- 


, (MM) 


•If).(MM) 
15 


"), urn 


6 

rn.(MM) 
70 


Power   Apparently   Generated   in   the   Secondary   Current.- -Based 

upon  the  calculation  of  100,000  volts  and  2  milliamperes  the  power 
irenerated  by  an  .r-ray  coil  would  be  .">00  watts,  and  with  100.000  volts 
and  1 ."»  milhampercs  the  apparent  result  would  be  1 .")()()  watts.  As 
the  power  ot  thf  primary  or  exciting  current  passing  through  the  coil 

1  I  'nri -<-li n't,    ;.ul '  (li'in  (  Icliicte  -li-r  Kocnt  p-n>t  ralili  n,  <  let.  L'."),  l'.M)4. 
-  Mav  •>    ll»i:i. 


THE    X-KAY  735 

may  bo  only  about  500  watts  and  1500  watts  respectively,  and  since  we 
know  that  nearly  half  of  the  power  in  the  secondary  is  wasted  in  the 
form  of  inverse;  discharge  which  must  be  suppressed,  there  is  apparently 
a  greater  output  than  intake;  of  power.  Of  course  this  would  be  an 
impossibility,  and  the  explanation  is  found  in  the  fact  that  the  meters 
indicate  the  maximum  of  the  successive  currents  rather  than  their  average 
strength. 

A  transformer,  with  a  primary  current  of  15  amperes  and  220  volts 
or  3-2  kilowatts,  may  yield  a  secondary  current  of  10  milliamperes,  and 
approximately  1  horse-power  or  740  watts  is  delivered  to  the  Coolidge 
tube  when  the  factors  are  5-inch  spark,  5(5,000  volts,  and  10  milliamperes. 
And  with  this,  characteristic  radiographie  exposures  at  23  inches  and 
using  a  Seed  x-ray  plate  would  be:  hand,  one  second;  elbow,  two;  ankle, 
two;  knee,  four;  shoulder,  eight;  chest,  ten;  hip,  twenty;  head,  laterally, 
twenty-five;  frontal  sinus,  fifty  seconds. 

The  energy  delivered  to  an  x-ray  tube1  increases  in  direct  proportion 
to  the  milliamperage  and  also  to  the  voltage1;  but  the  intensity  of  the 
resultant  x-ray  measureel  by  fluoroscopie-  brightness  and  photographic 
e'ffee't  varies  directly  in  proportion  to  the*  milliamperage  and  to  the 
square  of  the  voltage.  In  e^ae'h  case  the  high  tension  current  delivered 
to  the  x-ray  tube  is  referred  to. 

If  erne*  has  apparatus  which  allows  a  constant  direct  current  to  pass 
through  the  x-ray  tube1  anel  maintains  the  resistance*  or  spark  equivalent 
or  voltage  at  the  desired  value,  then  the  number  of  milliamperes  shows 
exactly  the  strength  of  the  x-ray  generated.  Without  these  factors  the 
milliamperemeter  is  useless  anel  the  whejle  application  of  the  x-ray  be- 
e'omes  a  matter  of  long  experience  or  e>f  dangerous  guesswork. 

Amperage  of  the  Secondary  Current. — The  currents  generated  by 
the  large  induction-coils  for  x-ray  and  high-frequency  currents  in  medical 
apparatus  anel  for  wireless  telegraphy  in  commercial  apparatus  have 
very  high  voltage  and  also  very  appreciable  amperage.  A  12-inch  spark 
means,  according  to  some  calculations,  100,000  to  300,000  volts,  anel  the 
strength  of  the  current  which  such  a  coil  will  send  through  the  enormous 
resistance  of  an  x-ray  tube  is  from  1  to  15  milliamperes.  The  currents 
are  rapidly  alternating  and,  like  most  other  induced  currents,  consist  of 
waves,  each  of  which  has  a  maximum  anel  a  minimum  strength.  The 
meter  shows  approximately  the  maximum  amperage  without  very  much 
regarel  to  the  average  strength,  either  of  the  impulses  alone  or  of  the 
impulses  anel  pauses  combined.  Hot-wire  meters  inelicate  the  current 
strength  regarelless  of  its  alternating  polarity,  while  electromagnetic 
meters  (galvanometers)  are  of  greatest  value  when  the  conditions  are 
such  that  the1  impulses  in  one  eliree-tion  are  prae'tically  suppressed. 

The  amperage  on  short-circuit  is  much  greater,  anel  when  the  poles 
are  brought  within  a  certain  number  of  inches  of  each  other  the  scries  of 
sparks  becomes  an  actual  flame  which  will  readily  set  fire  to  paper.  The 
length  of  the  flame  varies  with  different  makes  of  coil,  anel  its  am- 
perage is  about  equivalent  to  that  of  a  continuous  current  of  about  10 
or  20  milliamporcs.  The  maximum  of  each  impulse1  of  which  the  short- 
circuited  secondary  consists  is  probably  very  much  greater  than  10  or 
20  milliamperes  and  the  current  will  fuse  a  fine  wire  which  is  not  per- 
ceptibly warmed  by  a  voltaic  current  of  thai  amperage1.  When  the  two 
poles  are1  disconnected  a  spark  will  pass  to  a  person's  hanel  held  near 
either  pole  and  it  gives  quite' a  sharp  sensation  accompanied  by  a  reflex 


<•>!)  MKDICAL    KI.KCTHiriTY    AND    H()NT<iKX     KAYS 

contraction  which  causes  the  hand  to  he  jerked  away.      It   is  not  at  all 

dangerous  nor  actually  painful,  hut  is  Hither  disagreeable,  like  any  other 
electric  shock.  The  same  result  is  obtained  from  either  pole  or  from 
either  conducting  cord  when  the  coil  is  actuating  an  .r-ray  tube,  and  to  a 
less  extent  when  actuating  a  high-frequency  apparatus.  Precautions 
must  be  taken  not  to  allow  the  cords  to  come  too  near  the  patient  or 
operator  or  any  metallic  object,  like  part  of  the  tube-stand  or  table, 
through  which  a  shock  might  be  conducted.  For  the  same  reason  the 
induction-coil  and  all  the  connections  of  the  secondary  circuit  should  be 
at  an  ample  distance  from  other  wires  or  pipes  or  other  metallic  objects. 
Allowing  the  secondary  current  to  spark  across  to  the  \  10-volt  wires 
will  burn  out  all  the  fuses  along  that  line,  even  a  oO-ampere  fuse,  and 
ruin  the  socket  and  its  key  if  the  wires  have  come  from  an  ordinary 
electric-light  receptacle.  An  undesirable  and  somewhat  hazardous 
experiment  consists  in  holding  both  poles  of  an  ./'-ray  coil  while  the 
current  is  turned  on.  It  has  been  performed  a  sufficient  number  of 
times  without  any  bad  effects,  however,  to  show  that  there  is  no  danger 
of  serious  injury  from  accidental  contact  even  with  both  of  the  wires 
connected  with  an  .r-ray  coil.  Such  an  accident  should  be  guarded 
against,  however,  as  it  would  probably  produce  more  or  less  of  a  burn 
from  an  imperfect  contact  before  the  current  could  be  turned  off,  in 
addition  to  the  electric  shock.  These  currents  will  not  lea])  across  a 
space  of  more  than  a  very  few  inches  from  one  wire  to  sonic  uncharged 
body  when  the  .r-ray  is  in  operation.  This  is  because  the  .r-ray  circuit 
performs  the  function  of  a  volt  controller  and  the  free  potential  at  either 
pole  ot  the  coil  or  along  one  of  the  conducting  cords  is  only  half  of  the 
remainder  lelt  when  the  original  difference  in  potential  between  the  two 
poles  of  the  coil  ha-  been  diminished  by  the  conductivity  of  the  .r-ray 
tube.  And  when  an  ./'-ray  coil  is  used  to  actuate  a  high-frequency 
apparatus  the  length  of  spark  that  can  be  drawn  from  either  pole  of  the 
coil,  is  strictly  regulated  by  the  length  of  the  spark-gap  in  the  high- 
frequency  apparatus.  In  other  words,  if  the  two  poles  arc  brought 
so  close  together  by  an  electric  connection  that  thev  are  separated  bv 
an  air-gap  ot  only  \  inch,  no  amount  of  generating  power  will  increase 
difference  in  potential  beyond  that  which  is  required  to  flash 
the  -pace  of  ',  inch.  Additional  power  will  add  to  the  volume  of 
li-chargc  across  that  space,  but  cannot  increase  the  difference  in 
potent  ial.  The  fact  that  a  cert  am  resistance  is  necessarv  to  t  he  develop- 
:  a  certain  voltage  is  the  reason  why  a  spark  is  often  required 
n  one  cr  both  poles  of  a  static  machine  and  the  terminals  of  an 


The  conducting  cords  for  .r-ray  currents  should  belong  to  one  of  two 

those   which   frankly  admit    the  inability  of  their  insulation   to 

prevent    the  escape  of   the  current,   and   second,    those   which   have  an 

in'ch  actually  doe-  retain   the  current    sufficiently  to  permit 

-  bi-ing  handled  and  even  to  come  in  contact   will!  each  other 

The  best  cords  of  the  fir-t  kind  are  /,  jm.|,  j,,  diameter, 

:    in  "  •'•  •'•  insulating  layer  of  woven  silk  which  surrounds  a 

bundle  ol   _!.">  or2(;  parallel   copper  thread-.      Tlie   -ilk   insulation    keeps 

'Vires   in   a    flexible  cord   which   has   no  tendency   to  kink  or  tangle. 

I  I"-'1  <'"fd-  -hoiil.1  be  wound  upon  suitable  spring  reels  for  attachment 

«'"  l>"l«;s  "'  ;|"  •''-|';|V  <•"''  [!•'»>£•    "'"-      The  cords  may  he  drawn 

'""   '"  •'"'.'•   desired  distance,  remain  taut,  and  are  wound  up  automatic- 


THK    X-HAY 


737 


ally  whon  unfastened  from  (he  .r-ray  tube.  These  wires  should  be 
kept  from  contact  with  other  conduct  in"'  substances  because  the  current 
will  pass  right  through  the  insulation  and  damage  the  cord  by  burning 
a  hole  in  the  silk.  Such  an  occurrence  does  not  ruin  the  cord  at  all. 
because  the  insulation  was  never  intended  to  be  relied  upon,  and  a 
few  holes  in  it  do  not  matter.  Perfectly  bare  wires  in  the  form  of  a 
spiral  spring  are  cheap  and  convenient  as  to  stretching  out  to  any 
desired  posit  ion  of  the  tube,  but  t  hey  get  tangled  up  in  a  most  aggravating 
manner  and  are,  therefore,  not  to  be  recommended.  Flat  steel  tapes 
in  an  automatic  reel  are  serviceable,  but  not  so  easily  managed  in  all 
positions  of  the'  tube  as  the  covered  wires  above  described. 

The  ordinary  insulated  conducting  cords  covered  with  gutta-percha 
and  cotton  or  silk  are  not  suited  for  high-tension  currents.  They  are 
heavy  and  comparatively  lacking  in  flexibility  and,  worst  of  all,  they 
will  not  stand  the  electric  strain  for  an  instant  if  the  two  wires  happen  to 
cross  or  if  one  comes  into  contact  with  a 
good  conductor,  and  they  cannot  be 
handled  by  the  operator  or  be  allowed  to 
come  in  contact  with  the  patient.  They 
cannot  be  wound  upon  an  automatic  reel 
and  the  manipulation  of  the  tube  with 
reference  to  them  becomes  quite  a  study. 
Rubber  and  woven  silk  or  cotton  will  not 
resist  perforation  by  these  currents,  and 
after  having  once  touched  another  wire 
in  operation  with  the  .r-ray  such  a  cord 
loses  its  insulation  at  that  point  and  is 
destroyed  for  any  useful  purpose  it  might 
have  served  as  an  insulated  wire  for 
primary  currents  of  110  volts  or  less. 
These  wires  are  clumsy  and  their  in- 
insulation  is  useless  for  the  higher 
voltages. 

The  second  good  class  of  conducting 
cords  for  .r-ray  work  are  those  made  with 
a  sufficient  coating  of  shellacked  cloth  or 

plaster  of  Paris  to  be  impervious  even  to  these  high-voltage  currents 
from  small  .r-ray  coils.  They  have  an  outer  covering  of  woven  silk 
and  measure  about  \  inch  in  diameter.  They  are  comparatively  light 
for  cords  of  such  large  diameter  and  slightly  flexible,  enough  to  bend 
into  a  circle  4  inches  in  diameter,  but  should  not  be  bent  at  a  sharp 
angle  for  fear  of  breaking  the  insulation,  \\hen  connected  with  an 
.r-ray  coil  and  tube  in  operation  they  may  be  held  in  the  hand  or  may 
even  be  crossed.  /.  c.,  allowed  to  come  in  contact  with  each  other. 
The  latter  is  productive  of  a  sort  of  static  bree/e  discharge  between  the 
two  cords  accompanied  by  a  rustling  noise  and  violet  light.  It  is  not 
destructive,  but  it  is  unwise  to  allow  it  to  continue.  The  author  used 
to  employ  t  he>e  conducting  cords  in  all  cases  where  special  treatment 
.r-ray  tubes  were  held  in  the  hand.  The  small  cords  on  the  automatic 
reels  are  so  convenient  that  they  are  now  used  for  nearly  all  purposes, 
the  heavily  insulated  cords  being  reserved  for  application  of  the  .r-ray 
in  the  vagina  where  there  would  be  danger  of  the  wires  touching  some 
part  of  the  patient.  This  could  not  be  allowed  to  happen  with  the 
lightlv  insulated  wires,  but  with  these  other>  it  is  not  annoying.  It 


.— A'-ray 


<M  MEDICAL    KLKCTKICITY    AND    HOXTCKN    KAYS 

the  insulut  ion  becomes  broken  in  any  way.  that  port  ion  of  the  wire  would 
have  to  be  kept  t'rom  contact  with  any  conductor,  but  a  break  is  not  apt 
to  occur  in  ordinary  use. 

Other  methods  of  measuring  the  voltage  of  an  .r-ray  current 
besides  that  of  the  spin!  reniet  er  or  spark  distance  meter  are  by  means  of 
an  electrostatic  voltmeter  dependent  upon  the  attraction  of  two  op- 
positely charged  wires;  and  of  an  electrometer  such  as  is  used  in  measur- 
ing the  density  of  a  static  charge.  In  using  the  latter  there  is  a  metallic 
connection  between  one  pole  of  the. r-ray  coil  and  a  metal  surface  con- 
nected with  a  rod  to  which  a  pointer  is  hinged.  I'lider  the  repulsion 
caused  by  the  rod  and  the  pointer,  being  both  charged  with  the  same 
kind  of  electricity,  the  pointer  is  deflected  a  certain  distance.  The 
gradual  ions  on  the  dial  represent  certain  voltages  which  have  been 
determined  by  the  use  of  the  electrostatic  voltmeter  or  by  the  measure- 
ment of  a  current  from  a  transformer  whose  voltage  is  a  matter  of  matli- 
emat  ic  calculat  ion. 

The  voltage  and  amperage  of  the  high-frequency  currents  from  such 
an  apparatus  as  the  Oudin  resonator  actuated  by  an  ./'-ray  coil  are  both 
very  great.  They  present  a  much  greater  apparent  inconsistency 
between  the  amount  of  power  applied  to  the  apparatus  and  the  amount 
yielded  than  has  been  noted  in  the  case  of  the  .r-ray  coil.  The  high- 
frequency  current  often  has  a  power  of  10. 000  volts  and  250  milliam- 
peres.  indicated  by  the  distance  of  an  inch,  across  which  it  will  produce 
a  continuous  line  of  white  sparks,  and  by  a  hot  wire  milliamperemeter. 
This  apparently  possesses  a  power  of  10.000  volts  X  0.250  amperes  = 
25(K)  watts:  while  the  power  of  the  primary  current  in  the  .r-ray  coil 
may  be  only  100  volts  X  5  amperes  =  500  watts.  The  explanation  is 
the  same  as  in  the  case  of  other  induced  currents.  The  effect  registered 
by  i  lifferent  meters  is  rat  her  the  effect  of  1  lie  maximum  of  each  successive 
discharge  than  the  effect  of  the  averau'e  power  yielded  by  the  apparatus 
in  a  certain  length  of  time.  The  physical  effects,  like  fusing  fine  wires 
and  even  penetrating  several  inches  of  glass  by  fusing  a  path  for  itself 
through  ihe  solid  glass,  are  explained  on  the  same  ground.  The  mild 
character  of  the  physiologic  effect  is  altogether  astonishing  and  can 
be  explained  only  on  the  assumption  that  an  electric  discharge  with  al- 
ternations above  5000  to  the  second  lose-  its  power  to  excite  muscular 
contraction  and  certain  other  physiologic  effects.  This  applies,  of 
course,  only  to  the  case  in  which  the  body  forms  a  conductor  for  the 
high-frequency  current  produced  in  the  body  either  by  induction  or 
by  perfect  electric  connection  with  the  electrode  or  electrodes.  The 
-park  from  a  high-frequency  apparat  us  produce-  phy.-ical  and  physiologic 
effects  -inuiar  to  those  from  other  sources  of  high-tension  electricity. 

The  Method  of  Studying  the  Very  High-tension  Currents  from 
an  A'-Ray  Coil.  The  most  effective  apparatus  and  one  which  gives 
a  graphic  representation  of  the  strength,  direction,  and  duration  of  the 
impul-es  generated  bv  one  of  these  extremely  powerful  induction-coils 
i-  called  the  o-cil]<i-cope.  fSee  also  page  700.) 

It-  construction  is  shown  in  Fig.  HV  A  glass  tube  into  which 
wire-  are  .-ealed  at  each  end  is  sometimes  separated  into  two  halves  by  a 
thin  transverse  partition  of  glass  or  mica  and  .-oiuet  lines  has  no  parti- 
tion, [t  \<  exhau-ted  to  the  degree  of  vacuum  u-ual  in  (  ieissler  tubes. 
1  he  leading-in  wire.-  reach  to  within  a  -hort  distance  of  the  -eptum  and 
each  terminate-  in  a  -mooth  rounded  ext  remit  v.  Such  a  tube  mav  be 


THE    .r-KAY 


introduced  into  the  circuit  by  connect  ing  one  of  its  wires  to  a  conducting 
cord  trom  one  pole  of  the  x-ray  coil  and  the  other  of  its  wires  to  a  con- 
ducting cord  leading  to  the  proper  terminal  of  the  x-ray  tube.  In  this 
arrangement  the  currents  to  the. /'-ray  tube  all  pass  through  the  oscillo- 
scope. \\  hen  these  induced  currents  are  passing  there  will  be  a  play  of 
violet-colored  light  between  the  ends  of  the  leading-in  wires  and'the 
intercepting  diaphragm.  The  reflection  of  this  light  in  a  rapidly 
revolving  mirror  shows  that  it  develops  in  a  series  of  waves  in  alter- 
nate directions  and  separated  by  a  pause.  The  general  character  in 
one  of  Lewis  Jones'  experiments  (Fig.  4(iS)  was  similar  to  that  of 
the  secondary  currents  in  a  faradic  coil  without  an  iron  core.  If  the 
inverse  discharge  is  sunnressed  hv  the  proper  adjustment  of  spark- 

il'l 


gaps  or  ventril  tubes  or  self-induction  the  corresponding  inverse  portion 
of  the  wave  will  be  absent  from  the  tracing.  This  is  made  by  throwing 
the  reflection  of  the  spot  of  violet  light  from  the  revolving  mirror  upon 
a  photographic  plate.  Looking  at  the  reflection  in  the  revolving  mirror 
the  violet  light  does  not  look  like  a  simple  spot,  but  like  patches  of 
light  of  definite  shape,  most  probably  of  the  character  shown  in  Fig. 
h>S,  where  t  he  inverse  discharge  or  make  current  in  the  secondary  coil  is 
above  the  neutral  line  and  the  direct  or  break  current  is  below  it.  The 
rate  of  revolution  of  the  mirror  being  known,  we  may  calculate  from  the 
tracing  the  number  of  inverse  and  direct  discharges  per  second.  The 
proportion  of  the  time  occupied  by  each  as  compared  with  the  total  of 
each  period  or  cycle  is  indicated  and  also  the  relative  strength;  but  this 
method  does  not  directly  measure  the  voltage  or  amperage  of  these  cur- 
rents. 

Thi<  method  is  applicable  also  to  the  study  of  high-frequency  cur- 
rents. 

The  following  is  quoted  from  the  first  edition  of  this  work  (1910): 
"A  thought  has  occurred  to  the  present  author  that  this  method  of 
studying  induced  currents  will  ultimately  lead  to  the  discovery  of  a  per- 
fect apparatus  for  the  production  of  the  .r-ray.  The  ideal  current, 
according  to  my  view,  is  one  which  will  maintain  a  constant  difference 
of  potential  between  the  two  poles  of  the  .r-ray  tube  instead  of  the  rapid 
change  from  high  to  low  potential  or  even  to  an  inverse1  potential  as 
produced  by  present  methods.  The  ideal  chart  according  to  this  view 
would  show  a  uniform  elevation  instead  of  the  waves  in  the  present  chart. 
This  might  occur  from  each  individual  direct  discharge  being  length- 


740 


MKDICAL    KLK<  TKKITY    AND    H(  ).\T(  JKN     HAY 


ended  by  self-induct  ion  or  by  add  it  ional  capacity  in  t  he  primary  or  in  t  he 
secondary  circuit,  or  by  increased  rapidity  of  interruptions;  and  in 
either  case  it  pre.-uppn.-e-  the  complete  suppression  of  the  inverse 
discharge.  The  additional  capacity  might,  for  example,  be  a  con- 
denser, ot  which  1  he  t  wo  s urtaces  or  sets  of  met  al  sheet  s  were  of  enormous 
extent.  And  it  such  a  condevnser  were  placed  in  the  secondary  circuit 
the  insulating  plate.-  between  the  two  sets  of  armatures  would  have  to 
be  of  mvat  thickness  and  impenetrability.  The  only  ideal  generator 
of  r-rays  is  possibly  radium.  The  .r-rays  and  other  radial  ions  seem  to  be 
sent  out  from  radium  under  the  influe-nce-  of  a  constant  and  uniform 
force,  just  as  heat  and  light  ray-  or  waves  are  sent  out  from  a  body  that 
has  been  heated  while  hot  and  is  kept  at  that  temperature  bv  a  uniform 
source' of  heat.  *  >f  course,  the  heat  is  given  out  as  vibrations,  but  these 
are  millions  ot  times  a  second  and  are  like  the  r-ravs  from  a  tube  in 
which  the  two  electrodes  were,  according  to  the  author's  ideal  concep- 
tion, maintained  at  a  uniform  difference  of  potential.  Let  us  imagine 

a  hollow  metal  ball  (Fig.  liiid  with  such  thin 
walls  that  it  will  respond  to  the  very  slightest 
imaginable  variations  in  temperature  acting 
for  the  shortest  time,  and  have  this  heated 
by  a  gas-jet  the  pressure  of  which  varies 
from  its  maximum  down  to  zero,  or  which 
may  even  be  replaced  by  a  blast  of  cold  air. 
Then  the  heat  vibrations  would  be  sent  out 
in  varying  quantities,  and  if  the  variations  in 
the  source  of  heat  were  very  great  and  rather 
slow  there  would  IK-  perceptible  changes  in 
the  liu'lit  and  heat  given  out  by  the  hot  metal 
halL  ball.  We-  know  that  the  wave  lengths  of 

the  liii'ht  and  heat  vibrations  would  also  vary  with  the  temperature.  If 
the  variations  were  very  rapid  and  uniform  they  might  be  imperceptible 
and  the  metal  sphere  might  seem  to  be  giving  out  a  uniform  amount  and 
quantity  of  heat  and  light,  although  in  this  imaginary  case  of  a  metal 
re-ponding  instantly  to  every  variation  in  the  source  of  heat  the  light 
was  rapidly  varying  from  its  maximum  quantity  to  y.cvo,  and  its  wave 
I'-nu'h  was  al.-o  varvmi:'.  and  the  variations  in  the  heal  sent  out  were 
[er.  Su'-h  an  apparent  uniformity  of  heat  and  li^ht  emission  in 
•nee  of  extreme  rapidity  and  umionmtv  of  variations  is  atialo- 
best  conditions  we  are  at  present  able  to  secure  in  the  pro- 
he  r-rav.  At  present  the  radial  ions  from  an  .r-ray  tube  are 
vibrations  of  a  u'l'eat  man  v  different  wave-lengths  and  phys- 
•-iolotric  properties.  \\  ith  the  ideal  condition  of  a  uniform 
ifference  in  potential  between  !  he  two  electrodes  of  an 
e  -!  1011  Id  surely  be  able  t o  secure  a  uniform  production  of  rays 
probablv  be  able  to  produce  r-rays  all  of  tin-  same  \vave- 
.  ate  tin-  vvave-lenii't  h  according  to  the  de^ri-e  of  pene- 
rtie-  desired.  This  would  correspond  to  a  metal 
isolutelv  unitnrm 


ion  '  >f 
a  mix'  ire  i 
ical  and  pi 
and  ;i 

an   ;  ::.:.:  i 

' 
-Tihen 


an  un\"ar\'ing  gas- 
roin  a  lube  a!  the  present  lime  may  be  regulated 
ponderance  i>i  ray-  ni  a  certain  wave-length,  but 
lid  of  :  In-  scale  to  t  he  ot  her, 
'  |  >a  -s  (  hfoiigh  a  -licet  of  some 
rav.-  of 


Tin:  .r-KAY  741 

another  quality.     This  would  not    bo  necessary  if  it   were  possible  to 
excite  a  tulie  so  thai  all  the  rays  were  of  the  desired  quality." 

These  pages  wore  read  l>y  Messrs.  Sewall  ('a hot  and  Joseph  T. 
Shaw,  who  were  seeking  an  improved  ./-ray  u'onerator,  and  after  SOUK; 
yea;'-  <>l  experinietitat  ion  and  many  consultations  with  the  author  they 
have  produced  a  generator  of  a  direct  current  of  high  potential  and  of 
practically  unfluctuating  voltage.  This  is  described  on  page  7"j(). 

Induction-coils  for  Very  Heavy  Currents.- Coils  have  been 
constructed  (1!H)7)  by  the  Voreinigte  Kloktrotochnische  Institute, 
Frankfort  and  Aschafl'onburg.  producing  an  abnormally  powerful  second- 
ary discharge.  They  are  said  to  be  capable  oi  forcing  20  to  40  milliam- 


and  through  which  the  usual  type  of  "oil  will  onlv  send  .',  to  1  milliam- 
peres.  They  are  guaranteed  to  produce  a  chest  radiograph  in  from  one 
to  ten  seconds  without  an  intensifying  screen  and  are  said  to  produce 
pelvis  pictures  m  two  or  three  second-  under  favorable  circumstances. 
These  figures  are  for  a  coil  in  which  the  primary  spool  is  -10  inches  long 
and  the  distance  between  the  secondary  terminals  is  about  b'5  indies. 
It  weighs  about  1")0  pound.-.  1:  is  very  important  to  remember  that 
a  powerful  current  may  be  passing  through  the  primary,  as  indicated  by 
the  amperemeter,  and  a  relatively  heaw  current  through  the  tube,  as 
indicated  by  l  he  mi  11  (amperemeter,  and  st  ill  produce  no  ./'-radiance  at  all, 
or  so  defective  a  radiance  that  only  the  poore-t  sort  of  picture  could  be 
made,  and  that  would  require  an  excessively  lonir  exposure.  It  is  easv 
for  the  experienced  eye  to  note  the  defect  either  with  or  without  the 
fluoroseopo.  To  determine  the  cause  and  how  to  remedy  it  are  some- 
time- matters  of  great  technical  difficulty  and  it  is  to  assist  in  this  that 
the  many  details  in  this  chapter  have  been  written. 

Radiography  with  a  Single  Impulse.—  The  current  through  a  coil  or 
tran-former  is  turned  on  and  is  immediately  cut  off  by  the  blowing  out 
of  a  cartridge  fuse.  A  single  break  discharge  is  thus  produced  which 
excites  the  .r-ray  tube  for  an  instant.  The  Polyphos  ( 'o.  have  a  patent 
upon  an  outfit  in  which  there  is  so  little  resistance  that  at  the  single 
contact  there  is  a  tremendous  flow  of  current  and  an  extraordinary  de- 
velopment of  .r-ray  power  at  the  break.  It  is  thus  possible  to  take  a 
radiograph  of  a  crying  child.  YVappler,  in  this  country,  is  about  to 
manufacture  a  coil  or  transformer  of  this  type. 

Rapid  Radiography  with  Several  Parallel  Wehnelt  Interrupters.— 
This  method  is  said  to  have  been  devised  by  (iroedel.  of  Xauheim.  It 
is  applicable  to  an  ordinary  induction-coil  and  consists  in  connecting  the 
positive  electric-light  wire  with  three  large  platinum  points,  which  may 
be  in  a  -ingle  large  jar  or  in  three  separate  one-.  There  would  be  a  sin- 
gle !ar<re  lead  electrode  forming  the  negative  pole  of  the  interrupter  if  a 
single  large  jar  was  u.-ed,  or  in  the  other  case  the  three  lead  electrodes 
in  the  separate  jars  would  all  be  connected  with  a  single  wire  leading 
to  the  .r-ray  coil. 

The  direct  electric-liuht  current  of  110  to  2.~>0  volts  is  used  and  a 
primary  current  of  (10  to  (.H)  ampere-,  -ending  a  secondary  current  of  20 
to  .')()  ma.  through  the  .r-ray  tube.  An  exposure  of  one-fifth  to  one-half 
second  produces  an  excellent  radiograph  of  the  chest  when  all  the  con- 
dition- are  favorable.  A  heavy  anode  tube  is  required  and  a  quick  break 
-witch  to  prevent  arcinu  when  this  very  -it'onii  current  is  turned  off.  An 
automotic  circuit-breaker,  cuttinu'  off  the  current  alter  the  proper  time, 
i-  a  vorv  desirable  addition  to  the  outfit. 


(4'2  MKlMt  AI.    KI.KeTKHlTY    AND    KoXTCKX    KAYS 

The  coil  has  to  be  specially  adapted  to  this  purpose,  in  order  to  secure 
much  increase  in  .r-ray  power  by  the  addition  of  one  or  more  extra 
AVehnelt  interrupters. 

The  Tesla  High-frequency  Coil  for  x-Ray  Production.-  Any  alter- 
nating electric-light  current  may  be  connected  directly  with  the  pri- 
mary of  a  Tesla  transformer,  and  two  small  condensers  highly  insu- 
lated by  immersion  in  oil  have  a  spark-gap  between  the  two  primary 
armatures  and  their  secondary  armatures  are  connected  with  the 
primary  of  the  spark  coil.  A  small  .r-ray  apparatus  of  this  type  would 
have  about  tiO  turns  of  ]\o.  IS  gutta-percha-covered  copper  wire  for 
the  primary  and  about  MOO  turns  of  No.  MO  silk-covered  "magnet" 
wire  for  the  secondary.  The  terminals  of  the  latter  are  connected 
wit  h  t  he  .r-ray  t  ube. 

If  the  alternating  elect  ric-litrht  current  is  not  available  the  direct 
electric-light  currents  may  be  changed  by  a  rotary  transformer,  and  the 
alternating  current  thus  produced  may  be  used  to  actuate  a  Tesla  coil. 

An  .r-rav  tube  lights  un  with  the  discharge  from  a  Tesla  or  high- 


wire-  le.-id  ID  this  frnm  :HI  indil'-tioti-eoi]  whieli  is  n<>1  >ln>wr 


higli-l're(]iieiicy   apparat  u.-.   but    they      o   no     gve 
ratus  of  the  -nine  urade  upon  the  oilier  principle. 

The    reason    for   this    i-   the   alternating   chara  . 

Neither  pole  «\   the  apparatus  can  be  considered  the  negative  pole,  and 


hi-  means  a   very  ureat    \\a.-te  of  po\\er  a-  compare 


induction-coil.       The  latter  i 


more  pmvertul  at    the  moment    that    the  pnmar\'  current    i-  l)l'oketl  that 
the  Huhmkortt  coil  ha-  distinct   polarity,  and  one  pole  can  be  considered 
e     ce  o  -' 


Vi  •  and   t  he  older   I  he   pi  >-\\  ive  t  el 


THK    .T-HAV 


743 


Fig.  471.—  Step-up 
former:  P,  primary;  >',  ? 
arv. 


An  ordinary  .r-ray  tube  with  its  cathode  only  connected  with  the 
( hulin  resonator,  adjusted  to  give  a  4-inch  eflluve,  produces  a  moderately 
good  .r-ray.  No  other  connection  is  made  with  the  tube.  The  current 
traverses  the  tube  not  by  leakage  from  its  anode  extremity,  but  by 
back-and-forth  surging.  The  gas  in  the  .r-ray  tube  acts  as  a  condenser. 
Unrectified  Transformer  as  x-Ray  Generator.— The  construction  is 
simply  that  of  a  step-up  transformer  without  moving  parts,  if  one  ha? 
the  alternating  electric  light  current,  and  it  requires  only  tin 
a  motor  generator  if  one  has  the  direct  elec- 
tric current. 

Some  .r-ray  tubes,  notably  the  radiator 
type  of  Coolidge  tube  and  the  Renifar  gas- 
filled  tube,  are  so  constructed  as  to  trans- 
mit current  in  the  proper  direction  and  to 
suppress  the  inverse  current  more  or  less 
completely.  The  portable  outfit  described  in 
the  I".  S.  Army  .r-Ray  Manual'  and  used  by 
our  Army  consists  of  an  unrectified  trans- 
former and  a  radiator  type  Coolidge  tube. 

The  High-tension  Transformer. — A  pioneer  apparatus  of  this  form 
for  the  production  of  the  .r-ray  was  introduced  by  (laiffe,  of  Paris.  To 
make  a  transformer,  we  take  a  soft  iron  ring  (Fig.  471 )  and  wrap  a  part 
of  it  in  several  turns  of  insulated  wire"  through  which  passes  the  primary 
current,  and  wrap  another  or  the  same  part  of  the  ring  with  a  number  of 
turns  of  insulated  wire  in  which  the  secondary  current  is  to  be  generated. 
Fvery  time  the  current  starts  or  stops  in  the  primary  turns  of  a  wire  a 
current  is  induced  in  the  secondary  turns  of  wire  and  the  voltage  of  the 
t  wo  currents,  primary  and  secondary,  is  directly  proportional  to  t  he  num- 
ber of  turns  that  each  wire  makes  around  the  iron  ring.  This  is  a  matter 
of  ("very-day  use  in  electric  engineering,  and  if  the  transformer  is  one  for 
changing  from  a  low  to  a  high  voltage  the  appliance  is  called  a  "*t< p- 
iiji"  Irtntxfnrnifr.  The  appliance  for  changing  from  a  high  to  a  low  volt- 
age is  called  a  "step-down"  transformer.  Transformers  made  for 
practical  use  in  electric  welding  and  lighting  and  electric  power  genera- 
tors in  factories  are  so  perfect  that  the  voltage  is  changed  either  up  or 
down  with  the  loss  of  only  )]  per  cent,  of  the  power. 

( lail'fe's  transformer  for  .r-ray  and  high  frequency  use  must  be  run  on 
an  alternating  current,  and  where  only  a  direct  current  is  available  this 
must  be  changed  to  an  alternating  current  by  means  of  a  dynamo 
machine  known  as  a  motor  generator.  The  primary  current  is  regulated 
by  a  choke  coil,  or  inductance,  or  a  liquid  rheostat",  and  is  measured  bv 
an  amperemeter  and  a  voltmeter.  From  the  transformer  secondary 
wires  pass  to  the  pules  from  which  t  he  connect  ion  is  made  wit  h  t  he  ./'-ray 
tube.  ['he  strength  ot  the  current  passing  through  the  .r-rav  tube  i> 
indicated  by  a  milliainperemeter  placed  directly  in  the  circuit  supplying 
.r-ray  tube.  The  discharge  from  the  transformer  being  an  alternat- 
one.  two  vent  ril  tubes  are  introduced  on  t  he  secondary  circuit  to  take 
all  the  discharges  in  one  direction,  A  ventril  tube  is  attached  to 
i  pole  ot  the  secondary  and  these  two  tube-  are  connected.  They 
s  form  a  -hum  circuit  through  which  one  set  of  discharges  pass,  while 

.r-ray  t  ube.     A  vent  ril  t  ube.  it  \\  ill  be 
lavinir  much  the  same  character  as  an 


744 


MKDICAL    KLKCTUiriTY     AND    KONTt ;  K\     HAYS 


-ray  tube,  but   with  a  simple  cathode  and  anode  and  no  anticathodo. 

t  is  neci'ssary  that  it  should  l>e  provided  with  a  regulator  of  its  degrees 

f  vacuum,      \\ith  (  iail't'e's  apparatus  it    is  necessary  to  have  a  set   of 

ondensers  insulated  by   compressed  air,  and  there  is  also  a  liquid  re- 

-tance  on  each  of  t  he  secondary  wires.      In  l  hese  resistances  t  lie  current 

a-  to  pa-s  between  a  platinum  and  a  lead    point    through    dilute    sul- 

hunc  acid.       The  condensers  and  these  liquid  resistances  product1  uni- 

nnity  of  discharge  by   preventing  self-induction   in   the  turns  of  the 

condary   wire   in   the   transformer  from  a   sort    of  backing  up  action 

hich  would  occur  especially  in  connection  with  a  high-frequency  sole- 

'  !'.<  {  i  >r  resonal  or. 

The  principle  of  the  transformer  for  actuating  an  .r-ray  tube  is  not  a 


;ie\v  one.  but  it  gives  Mich  uniform  and  powerful  currents  that  with 
1110*1  manulad  urer-  it  has  now  n(.'2l)i  displaced  the  more  uncertain 
ou'fiis  thai  depend  upon  an  interrupter  and  an  induct  ion-coil. 

fi.iiffe's  tran-1'ormer  apparatus  i  Fig-.  172  17  I1,  tor  high-frequency 
current-  and  the  .r-ray,  depend-  partly  upon  the  use  of  compressed  air 
or  ii;i-  as  a  dielectric  or  insulating  medium,  and  partlv  upon  the  intro- 
duction ot  re-!-tance-  or  inductance-  in  the  prmiarv  circuit,  or  derived 
ir'om  the  -econdary  circuit  to  prevent  the  formation  of  an  arc  at  the 

["he  fir-1  i-  ba-ed  upon  the  supposed  lad  that  compressed  air  or 
other  Lra-  i-  a  better  iion-condudor  ot  eflluves  or  disruptive  discharges 
I  han  ua-e-  a '  i  u'd  nri  r\  pressures,  and  thai  it  has  t  he  advantage  over  solid 
m.-ulation  like  parailin  or  liquid  in-ulation  like  pet  roleum  oil,  that  it  is 
neou-,  whereas,  a  local  delect  m  these  others  might 
i  ice  M]-.  Tin-  po-Moihi  v  o]  a  change  occurring  in  the  pressure  of  air  inside 


THE   X-ltAY 


the  ease  containing  the  transformer  produces  ;i  danger  to  (ho  apparatus 
from  a  reduction  in  the  insulation  which  is  guarded  against  by  a  safety 
device.  There  is  an  orifice  at  a  certain  part  of  the  case  which  is  closed 
either  by  a  flexible  membrane  or  else  by  a  piston.  If  a  leak  occurs 
the  reduction  in  pressure  will  produce  motion  in  the  diaphragm  or  in 
the  piston,  and  this  motion  actuates  a  quick  break  switch  which  turns 
off  the  primary  current.  'The  connection  between  the  piston  or  the 
membrane  and  the  switch  may  be  a  purely  mechanical  one,  the  motion 

l 


in  which  motion  produced  by  th 
elect  ric  contact .  and  the  current 
so  turned  on  operates  a  relay 
which  causes  the  circuit  breaker 
to  act  and  cut  off  the  primary 
current . 

Tin*  suppression  of  the  arc 
which  tends  to  form  at  the 
spark-gap  is  a  matter  of  experi- 
ment with  different  combina- 
tions of  inductance.  (Col 


e    owern 


of  the  pressure  makes  an 


\vhoso  self-induction  produce  a  counter-electromotive  force  at  the 
proper  moment  to  oppose  the  break  spark,  capacities  whose  function  is 
like  that  of  the  condenser  of  an  induction-coil  to  receive  the  charge 
generated  by  the  increased  electromotive  force  when  the  current  is 
broken  and  which  without  a  large  capacity  to  receive  it  would  over- 
charge1 the  two  poles  of  tho  spark-uap  and  maintain  an  arc.)  These 
capacities  are  connected  with  the  secondary  circuit.  Resistances  may 
be  placed  in  the  primary  circuit  of  a  transformer  which  v.  ill  have  a 
similar  eifcet .  The  mag;  lit  udo  of  the  capacities  and  of  tho  inductances  to 
be  introduced  varies  ;ieeording  to  the  nrecise  conditions,  and  in  some 


7-lli  MKDICAL    KLKlTKK  ITY    AND    K(")NT(;  KN    HAYS 

cases  of  a  transformer  with  suitable  resistances  the  other  two  means  may 
be  dispensed  with  altogether. 

Malaquin  and  Charbonncau  have  constructed  a  transformer  giving 
200,000  volts.  It  has  two  secondary  circuits  around  a  closed  magnetic 
ring.  Provided  with  a  rectifier,  it  is  said  to  excite  S  .r-ray  tubes  in 
series. 

Alternating  Current  Generator  with  High-tension  Rectifier  for  x- 
Ray.  At  the  present  writing  (101!))  this  seems  to  be  one  of  the  most 
desirable  types  of  .r-ray  generator.  A  transformer  is  used  which  pro- 
duces an  alternating  current  of  10.000  to  100.000  volts  and  is  actuated 
by  from  2  to  10  kilowatts,  depending  upon  the  amount  of  primary  cur- 
rent. This  is  from  20  to  100  amperes  of  110-volt  alternating  elec- 
tric-light current.  This  is  the  generator  in  Snook's  apparatus,  made  by 
the  Roentgen  Manufacturing  Company.  Many  others  manufacture 
similar  apparatus.  If  one  has  the  direct  electric-light  current  a  motor 
generator  is  required  to  produce  an  alternating  current.  The  current 
is  rectified  by  a  commutator  in  such  a  way  that  the  top  of  each  wave 
in  the  right  direction  is  utilized.  No  ventril  tube  or  spark-gap  is  re- 
quired. The  amount  of  cm-rent  sent  through  an  .r-ray  tube  may  be 
50  ma.  or  more.  The  author  has  seen  excellent  radiographs  of  the 
chest  which  were  made  by  the  late  Dr.  Leonard  in  an  estimated  time 
of  one-half  second,  and  pelvic  radiographs  made  with  an  exposure  of 
two  seconds.  I)0th  of  these  were  without  an  intensifying  screen.  The 
thorax  pictures  showed  the  diaphragm  and  heart  with  clear  outlines  ap- 
proaching those  obtained  when  a  dead  person  is  radiographed;  they 
also  showed  the  space  between  the  heart  and  the  diaphragm,  which  is 
usually  demonstrable  only  by  the  fluoroscope.  It  is  now  practicable 
to  make  gastro-intestinal  radiographs  in  one-fifth  second. 

The  greatest  difficulty  in  the  use  of  enormously  powerful  currents 
is  going  to  be  with  the  ./'-ray  tubes.  A  continuous  discharge  of  50  ma. 
or  more  will  develop  a  temperature  of  2000°  or  :>000°  K.  at  the  focus  of 
the  .r-ray  tube  and  fuse  even  iridoplat inum  in  a  short  time.  Solid 
copper  targets  with  tungsten  buttons  are  excellent,  and  solid  tungsten 
targets,  as  in  the  original  <  'oolidge  tube,  are  still  more  heat  resistant. 

Secondary  Rays  from  a  Tube  Actuated  by  Such  a  Transformer.— 
It!  a  personal  communication  to  the  author  I  )r.  Leonard  expressed 
thi'  belief  that  the  unidirectional  character  of  the  discharge  through 
I  he  .r-ray  tube  results  m  a  radiance  tree  from  secondary  or  vagabond 
rays,  ;it:d  that,  therefore,  no  diaphragm  would  be  necessary  to  cut  off 
the-e  rays  ;,ij(|  secure  nood  definition.  lie  ~.-j\<\  that  in  renal  calculus 
case-  the  amount  of  definition  was  so  great  as  even  to  be  confus- 
ing. This  prediction  has  not  been  verified  with  gas-filled  tubes,  but 
is  partiallv  true  with  the  ('oolidge  tube.  At  the  author's  request  1  )r. 
Leonard  tried  the  author's  experiment  in  which  a  silver  dollar  was 
interposed  between  the  ./'-ray  tube  and  a  penny,  so  that  the  latter 
vva~  IM  the  shadow  of  the  former.  The  pennv  was  readily  visible  with 
thi-  fluoroscopi  and  in  a  radiograph.  This  was  also  the  case  when  the 
dollar  was  -imported  upon  a  sheet  of  paper  \\hich  Dr.  Leonard  thought 
would  cut  of]  -econdary  rays  arising  from  the  tube.  Hi-  conclusion  was 
that  the  ima'_[c  (,t  i  he  penny  was  produced  bv  rays  which  had  passed 

-liver    dollar.       A    piece   of    heaw 

the    s;,||]e    result    a*    the    -i!ver   dollar,    but    with    more    HI 
U'ed    to    the    greater    dil'lUs'ioii    of    the    .r-ra  v    bv    the    lead 


TIIK    X-RAY 


747 


in  each  case  \vas  7  inches  from  the  plate  and  its  image  showed  no  hala- 
tion. 

The  author  has  made  a  number  of  very  interesting  experiments, 
from  which  he  draws  the  conclusion  that  the  vagabond  rays  are, 
most  of  them,  not  arrested  by  paper  or  even  by  heavy  sole-leather, 
and  that  they  arise  under  ordinary  circumstances  for  all  practical  pur- 
poses from  the  glass  walls  of  the  illuminated  hemisphere  of  the  x-ray 


tube.  Hi-  experiments  do  not  enable  him  to  say  whether  these  second- 
ary rays  are  due  to  cathode  rays  or  x-rays  from  the  focus  on  the  anti- 
cathode  striking  the  glass  wall  of  the  illuminated  hemisphere,  but  hi- 
belief  is  that  they  are  due  chiefly  to  the  impact  ot  cathode  rays.  In- 
verse discharge  causes  cathode  rays  to  strike  the  iila-s  wall  of  the  tube 
and  give  rise  to  disturbing  x-rays  from  parts  outside  of  the  illuminated 
hemisphere,  and  in  this  way  add  the  blurring  due  to  the  secondary  ray> 


7-1S  MEDICAL    KLK(  THiriTY    AND    KONTCJKN    HAYS 

from  the  illuminated  hemisphere  alone.     Xo  amount  of  rectification  of 

the  current  i<  going  to  remove  the  latter  source  of  secondary  rays.  The 
most  practicable  ways  to  deal  with  this  are  by  the  use  of  a  diaphragm 
to  cut  oft  1  he  -eciiinlary  ra\'s  and  by  1  he  use  of  an  .r-ray  1  ube  wit  h  a  very 
-mall  active  bulb  communicating  with  a  larger  one  acting  sim])ly  as  a 
gas  container.  The  author's  cellular  radiating  diaphragm  gives  good 
definition  over  a-  wide  an  angle  as  mav  be  desired.  It  may  be  con- 
strticted  to  illuminale  almost  a  hemisphere.  Xo  limitation  as  to  the 
Mivngth  of  current  and  the  consequent  intensity  of  the  radiance  results 
Iron i  t  lie  use  of  a  diaphragm.  1 1  is  contact  diaphragm  is  especially  useful. 

The  use  ot  an  .r-ray  tube  with  only  a  small  surface  for  the  radiation 
of  secondary  ray--  while  permitting  of  the  radiation  of  direct  rays 
through  almost  a  hemisphere  is  also  believed  to  be  original  with  the 
author.  Hut  the  gla>s  i-  so  near  the  anticalhode  that  it  would  soften 
if  heavy  currents  were  used. 

The  (  'oolidii'e  or  electron  discharge  .r-ray  tube  obviates  this  difficulty 
by  producing  practically  no  .r-rays  from  its  glass  wall. 

Kny-Scheerer  "Interrupterless"  x-Ray  Apparatus.-  The  Kny- 
Scheerer  "interrupt erloss"  apparatus,  developed  from  Snook's  inven- 
tion Fig.  \7~>t.  comprises  a  small  stand  upon  which  are  mounted 
the  necessary  switches  and  rheostats  and  a  cabinet,  in  which  is  a 
motor  generator  (  (',  Fig.  47(i),  a  step-up  transformer  (T  and  h  <i). 
and  a  high-tension  commutator  (bey,  etc.),  which  is  mounted  upon 
the  same  .-halt  us  the  motor  generator.  This  high-tension  ivciilier  is, 
therefore,  synchronous  with  the  alternating  current  furnished  by  the 
motor  generator  to  the  step-up  transformer. 

\\heii  n  is  the  positive  secondary  pole  of  the  step-up  transformer, 
the  positive  current  passes  through  //  and  the  metal  strip  N  to  the  ter- 
minal '  .  t  hen  to  t  he  anode  ol  1  he  ./'-rav  1  ubc.  and  I  roin  t  he  cat  hod  e  of  the 
.r-ray  tube  to  the  terminal  /.  from  hen-  it  passes  through  the  metal 
-t  rip  .\  and  '/  to  //,  the  negat  i  ve  pole  ot  t  lie  t  raiisformer. 

]  )  i  ring  this  time  t  he  po-it  i  ve  current  cannot  reach  the  cat  h  ode  of  t  he 

r-ray   tube   because   the   insulated   part    ot    the   right    ['evolving  disk  is 

•      posed.      The    insulated    part    of   the   left    commutator  disk    is   also 

in'erposed  in  the  path  from  the  negative  pole  to  the  anode  ol  the  ./--ray 


At    the   other   pha.-e  of   the   high-tension   current    both   commutator 

h-k.-  have  performed  a  half-revolut  ion,  so  thai  a  complete  metallic  pat  h 

ti  i  shed  by  h .  which  i-  now  the  posit  ive  pole,  t  h  rough  v  and  >',  and  c 

'  o   t  he   liliode  of   the  .;'-I'a  V   til  be.         1  "rolll   the  ca  t  hoi  le  of  1  lie  J'-I'aV   t  llbe  1  lie 

it  i'  e  current  passes  to  /'and  .S'.  which  is  now  in  :i  line  bet  ween  /'  and  /^,, 
•  h   it    passes  to  '/,  which  i-  now  the  negat  ive  pole  of  t  he  t  rails- 

The  ••',,','.  lit  delivered  to  the  r-ray  tube  is  unidirectional  and  pulsat- 
ing I  iu.  1 77  .  and  is  much  less  dest  n  let  ive  ol  I  ubes  than  t  he  all  ernat  ing 
discharge  from  an  ordinarv  induction-coil,  as  in  !•  ig.  !7<V 

The  simplc-1  type  of  this  apparatus  i-  I  he  one  made  lor  use  will) 
reel  electric-light  current,  because  the  high-tension  commutator  is 
made  ab-oluie)\  synchronous  with  the  alternating  current  supplied  to 
'he  transformer  by  mouminu'  the  commutator  upon  i  he  -ame  shaft  as 
the  motor  Lienerator.  The  alternating  electric-light  current  and  triple 
ami  other  polvpha-e  current-  could  be  supplied  immediately  to  the 
traii-forme)  except  for  i  he  diflieulty  of  securing  absolute  synchronism 


THK    X'-KAY 


749 


-Transformer  and  high-tension  commutator  of  Knv-Scheerer  "  interrupted*: 


— Current  delivered  to  .r-rav  tube  bv  t  raiisfonni-r  with  hisih-ti-nsion  coiniuut  :ii 


Jjia.p'ram  af  flie  currenf  m  CL  tu.bt 
Ay   <xn.  /natucfia/i    COL/ 


750  MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

in  the  separate  motor  which  would  be  required  to  run  the  commuta- 
tor. This  synchronism  will  probably  be  attained  in  the  future,  but  for 
the  present  the  most  reliable  method  for  employing  the  alternating 
electric-light  current  or  multiple  phase  current  is  to  use  it  to  run  a  motor 
generator  with  the  high-tension  commutator  mounted  upon  its  shaft. 

Waitc  and  liurthtt  and  \Vapplcr  an'  among  the  American  manufac- 
turers who  make'  excellent  transformers  for  .r-ray  work. 

Open  or  Closed  Core  Transformers  for  ./-Ray  Work. — There  is  an 
impression  that  a  transformer  in  which  there  is  not  a  complete  iron  ring 
gives  a  better  quality  of  .r-ray  for  such  subjects  as  the  frontal  sinus. 
This  be  should  determined  by  the  manufacturers. 

A  0-inch  transformer  is  excellent  for  "instantaneous"  Kontgenography 
and  for  telerfmtgenography.  The  maximum  capacity  of  such  an  ap- 
paratus is  4  kilowatts  and  the  output  can  be  regulated  for  the  mildest 
radiotherapy  and  for  exciting  high-frequency  apparatus.  They  are 
made  up  to  11  kilowatt  capacity,  which  of  course  is  much  better. 

Direct  Current  Motor  Generator  for  .r-Ray  Work.  An  apparatus 
of  this  kind  was  under  construction  by  the  Baker  Klectric  Company  at 
the  publication  of  the  first  edition  of  the  present  work,  and  was  de- 
signed to  develop  a  continuous  direct  current  of  50.000  volts  and  an 
energy  of  4\  kilowatts.  This  means  the  use  of  about  50  amperes  of  110- 
volt  direct  current  to  run  the  motor.  Seven  or  eight  horse-power  are 
generated  and  a  shock  from  this  current  will  be  a  much  more  serious 
matter  than  one  from  an  ordinary  coil  or  static  machine.  Klectric 
engineers  had  up  to  that  time  considered  10,000  volts  the  practical  limit 
in  generating  direct  currents.  It  has  not  been  brought  to  perfection. 

Unfluctuating,  High  Potential  Constant  Current  Generator  for  Excit- 
ing an  .r-Ray  Tube.— In  the  first  edition  of  this  work  (page  G03)  the 
author  expressed  the  opinion  that  neither  the  induction-coil  or  the  static 
machine  or  the  transformer  with  a  high-tension  rectifier,  or  the  Cirisso- 
nator  with  its  series  of  impulses  in  the  right  direction,  was  the  ideal 
generator  for  .r-ray  purposes,  and  that  a  generator  of  a  constant,  and,  of 
course,  unidirectional  high  potential  current  which  could  be  regulated 
to  any  voltage  would  be  preferable  for  the  following  reasons: 

The  discovery  of  this  apparatus  came  about  from  the  perusal  of 
these  paragraphs  by  Messrs.  Cabot  and  Shaw,  electric  engineers 
engaged  in  the  manufacture  of  high-tension  apparatus  for  wireless 
telegraphy  and  other  purposes,  and  Air.  Cabot,  having  already  been  at 
work  upon  a  means  of  generating  high-tension  direct  current  for  electro- 
metallurgy,  they  decided  to  apply  their  invention,  in  the  first  place, 
to  the  generation  of  current  for  .r-ray  purposes.  Their  first  apparatus, 
the  heterodyne,  consisted  of  a  transformer  in  which  an  alternating  cur- 
rent of  '2'20  volts  was  <tepped  up  to  a  current  of  many  thousand  volts, 
which  wa<  made  unidirectional  and  practically  constant  by  means  of 
condensers  of  verv  great  capacity,  and  inductances  acting  as  choke1  coils 
for  >uppre>sing  currents  in  the  wrong  direction. 

This  wa>  an  advance  over  the  (iris.wttntoT,  which  gave  a  series  of 
-econdary  currents  in  the  right  direction,  but,  of  course,  with  a  voltage 
varying  from  /ero  to  a  certain  maximum.  The  Cabot  heterodyne,  on 
the  i •(![ it  rary .  furnished  a  constant  difference  of  potent  ial  at  the  terminals 
ot  I  he  ./'-ray  t  ube.  An  oscilloscope  in  series  with  t  he  .r-ra  v  t  ube  showed  a 
continuous  luminous  band  in  a  revolving  mirror  instead  of  the  series  of 
tla-he-  seen  with  anv  previous  generator.  The  .r-rav  tube  itself  showed 


THK    .T-KAY 


751 


continuous  luminosity  in  a  revolving  mirror,  and  the  .r-rays  were  believed 
to  l>e  approximately  homogeneous,  all  being  produced  by  electrons 
traveling  at  about  the  same  speed  under  the  impulse  of  an  unvarying 
voltage.  It  was  at  this  stage  that  the  author  was  first  visited  by  Messrs. 
( 'abot  and  Shaw,  and,  while  this  was  recognized  as  a  distinct  step  toward 
his  ideal,  it  seemed  to  him  that  too  much  power  was  wasted,  and  that  the 
correlation  of  the  various  capacities  and  inductances  was  a  complicated 
matter,  and  probably  not  subject  to  accurate  regulation  for  the  different 
voltages  and  amperages  required  for  all  radiographic  and  treatment  work. 


l-'iir.   li't. — ( 'alxit    high-potential  direct   current  converter.      Delivers  t 


nfluctuating, 


VisiMe  in  t  lie  glass  case  is  a  lo\v  volume  triple-phase  generator,  the  currei 
is  Mepped  up  i>y  t  hree  transformers,  one  for  each  phase,  concealed  in  t  he  ha.-  '.  The  high- 
tension  triple-phase  current  reaches  the  .r-ray  terminals  through  a  connnut:  tor  visihle  in 
the  glass  ca.-e. 

In  another  glass  case  on  top  the  author  has  a  high-tension  interrupter  and  condenser, 
hy  mean:-  of  \vhifh  the  current  is  catised  to  flow  through  the  tuhe  only  half  or  only 
one-tenth  of  the  time.  This  is  for  use  in  fluoro-<-opv  and  radiotherapy. 


The  final  development  is  the  Cnhnf  high- potential  nnixfunt  rnltage 
<l<'/irr<ifnr,  which  ret  mi  res  the  use  of  no  condensers  or  choke  coils,  and 
transforms  a  direct  current  of  220  volts  into  a  continuous  direct  current 
of  from  10,000  to  1  1-0.000  volts,  with  the  loss  of  about  1  or  2  per  cent,  of 
energy.  This  is  accomplished  wit  hoi  it  t  he  use  of  condensers  or  induct  ive 
resistances.  The  220-volts  direct  current  operates  a  rotary  transformer, 
producing  triple-phase  currents.  These  pass  through  the  primary  of  a 
>et  of  three  transformers,  connected  in  such  a  way  as  practically  to  torm 
a  (Iramme  ring,  and  if  the  same  strength  of  triple-phase  current  is  used. 


7.V2  MKDICAL    KLK(   rUICITY    AM)    HO.VRiKX    RAYS 

of  course  the  soconciary  winding  at  opposite  ends  of  :iny  diameter  shows 
a  certain  difference  in  potential  equal  to  that  of  any  other  opposite  points. 
If  the  current  were  taken  from  any  two  fixed  points  of  the  secondary 
winding  it  would  he  a  hiidi-tension  alternating:  current:  hut  collecting 
this  secondary  current  from  portions  hy  hrushes  which  advance  at  the 
same  rate  as  the  variation  in  the  current  secures  an  unrliietuating  sec- 


^£    £%  t 

•»"-*«**• 

,  HK®g 


.        *•».  r»-     ^«  f 

"        «.«,  *tk 


I:'     !--'i       i   niitpi!   |i:incl  fur  Caliot   Inch  pfitcnti:il  direct  current   converter:     A,  Mil- 

1  '.  nvolt  inet-T:     < ',    primary    iitiiliicter;     I-.,    nuality    ;  r:it  in  of  t  ran>fonii:ition1 

:    •,    :.    •'  i-    h  •      ihandotied;     I).   i|iiatitit>'    ire-i~t:uice   reirul.'tinr     li-\-cr:    !•'.   (iperatinn 

irn  nl    -witi-li;    II.   -t'irtiiiiz   '»>\:    I.   automatic  o\  rrload   circuit    breaker. 

•  :     not   -iiown.      It   may  l.e-.-t  for  expo-ure-  of  frum  one-tliirty-scfond  to 

i]  \  ,-r^ion  <  '«>.,  lirookline.  Ma—.). 

ondai'y  t'Ui'i'i-nt.      The  voltage  is  so  ln<ih  thai   the  lirushes  are  applied  at 
flu'  outside  instead  of  near  the  axle,  a-  in  ordinary  dynamos. 

\\hile  i:  i-  equivalent  to  a  (Iramme  rmu'.  the  Iran-former  looks 
more  like  three  ordinary  "step-up"  transformers.  The  <erondary  is  in 
many  ditleivni  di-k  -ections,  so  that  anv  part  that  hreak<  down  can  he 
ea-ily  rephu-i'd.  There  i-  a  rheostat  to  regulate  the  amperau'e  of  the 


THE    X-KAY  7f>3 

primary  current,  and  consequently  thai  of  the  secondary  current,  but, 
of  course,  with  a  certain  adjustment  of  the  apparatus  the  voltage  at- 
tained will  be  higher  the  »Teuter  the  decree  of  vacuum  in  the  tube,  and 
the  number  of  milliamperes  passing  through  the  tube  will  be  corres- 
pondingly less. 

(ienerally  speaking,  with  an  unfluctuating  voltage,  each  10,000  volts, 
corresponds  to  1  degree  Benoist,  so  that  90,000  volts  indicate  x-ray  of 
about  No.  9  Benoist,  and  the  greater  the  number  of  milliamperes  sent 
through  the  tube  at  this  voltage  the  more  quickly  a  radiograph  will  be 
produced  or  a  given  therapeutic  effect  obtained.  Cabot's  experiments 
show  that  with  this  voltage  an  exposure  of  3400  milliampere  seconds,  at 
10  inches  from  the  skin  equal  1  Sabouraud-Xoire  dose.  According  to 
this  estimate,  if  the  anticathode  were  10  inches  from  the  skin  and  there 
were  34  milliamperes  passing  through  the  x-ray  tube,  an  exposure,  or  a 
series  of  exposures,  amounting  in  all  to  one  hundred  seconds,  would 
produce  a  Sabouraud  dose.  And,  again,  if  there  were  3.4  milliamperes 
passing  through  the  tube  at  the  same  voltage,  representing  the  same 
degree  of  vacuum  and  the  same  quality  of  x-ray,  an  exposure  of  one  thou- 
sand seconds  at  10  inches  from  the  anticathode  to  the  skin  would  pro- 
duce a  Sabouraud  dose  of  /H  Holzknecht  units. 

Currents  sent  through  the  x-ray  tube  by  such  a  generator  must  be 
prevented  from  undergoing  oscillations  analogous  to  those  shown  by  the 
1 10-volts  direct  current  when  supplied  to  an  electric,  arc  with  a  condenser, 
and  known  as  the  singing  arc,  page  640.  Oscillation  stoppers  an1,  there- 
fore, provided,  which  consist  of  spirals  of  fine  wire  wound  over  hollow  card- 
board cylinders.  One  of  these  is  in  circuit  at  each  secondary  terminal. 
An  x-ray  tube,  with  the  proper  degree  of  vacuum,  excited  by  this  appara- 
tus, shows  no  inverse  discharge  at  all  in  the  oscilloscope,  and  no  spark- 
gaps  or  ventril  tubes  are  required  for  radiography  or  Rontgenotherapy. 
But  a  tube  with  too  high  a  degree  of  vacuum  shows  rings  indicative 
of  inverse  discharge,  and  this  is  confirmed  by  the  oscilloscope.  These 
last  two  sentences  apply  also  to  its  use  with  the  Coolidge  tube,  inverse 
being  shown  by  green  streaks  near  the  cathodal  prolongation  of  the  bulb. 

The  apparatus  consists  of  several  different  parts.  At  the  bottom 
there  is  the  transformer,  or  rather  then1  art1  three  transformers  for  pro- 
ducing the  high-potential  current  from  the  triple-phase  primary  current. 
This  section  may  be  enclosed  in  wood  and  requires  no  attention.  As 
originally  constructed  there  was  a  variable  ratio  of  transformation,  but 
I  have  abandoned  this  in  favor  of  a  fixed  relation  between  the  number 
of  turns  in  the  primary  and  secondary  windings.  The  section  above 
this  contains  a  motor  generator  of  triple-phase  currents,  having  hard- 
rubber  revolving  disks  mounted  upon  its  axle,  and  pressing  against 
the  outer  edge  of  each  disk  are  metal  springs  acting  as  collecting  brushes 
for  the  high-tension  current.  This  part  of  the  apparatus  had  better  be 
enclosed  in  glass,  so  that  one  may  see  that  these  contacts  are  all  right. 
There  are  t  wo  oil-wells,  which  should  be  kept  full  to  lubricate  the  bearings 
ot  t  his  mot  or  generator. 

There  is  a  milliamperemeter  through  which  the  high-tension  current 
passes.  There  is  also  a  voltmeter  upon  the  switch-board  winch  in- 
dicates upon  a  dial  the  voltage  at  the  terminals  of  the  x-ray  tube. 
This  does  away  entirely  with  need  for  measuring  the  parallel  spark- 
gap.  The  voltage  may  be  somewhat  varied  by  changing  the  strength 
of  the  current  applied  by  the  generator,  but  may  be  varied  from  le>s 
4S 


754  MKDH'AL    ELKCTRICITY    AND    RoNTGKN    RAYS 

than  5000  volts  to  more  than  100,000  volts  by  regulating  the  resistance 
of  the  .r-ray  tube. 

A  number  of  fuses  and  an  automatic  circuit -breaker  protect  the  ap- 
paratus from  too  heavy  currents. 

All  movable  pails,  including  the  motor  generator  of  triple-phase 
currents,  are  fastened  upon  the1  same  shaft  and.  of  course,  move  syn- 
chronously. The  multiplicity  of  wires  and  of  fixed  and  movable  con- 
tacts gives  such  a  perfect  result  that  the  oscilloscope  detects  no  inverse 
current,  and  if  tin1  oscilloscope  is  viewed  in  a  revolving  mirror  the  image 
of  the  light  is  drawn  out  into  a  ribbon,  not  separated  into  a  series  of 
flashes,  as  is  the  case  with  an  induction  coil  with  or  without  a  ventril 
tube,  or  with  a  transformer  with  a  high-tension  rectifier. 

The  author's  generator  has  been  in  daily  use  for  several  years,  making 
thousands  of  exposures  for  treatment  and  therapy.  It  employs  the 
220  volts  direct  current  controlled  by  a  rheostat.  The  original  trans- 
former unit  was  provided  with  means  of  varying  the  voltage  by  selecting 
the  number  of  turns  of  primary  winding,  but  this  feature1  has  been  dis- 
carded in  the  present  transformer.  On  open  circuit,  without  an  .r-ray 
tube1,  even  the  weakest  primary  current  produces  a  secondary  voltage 
of  about  HO  kilovolts;  stronger  primary  currents  increase  this  voltage 
and  a  very  strong  primary  current  would  produce  a  secondary  voltage 
in  excess  of  100.000  with  danger  of  breaking  down  the  insulation  in  some 
part  of  the  transformer. 

With  about  three-quarters  of  the  rheostat  resistance  and  a  high 
degree  of  incandescence  in  the  filament  this  generator  will  produce  about 
10.000  volts  and  send  about  20  ma.  through  the  ( 'oolidge  tube.  Chang- 
ing the  degree  of  filament  incandescence  alone,  we  can  readily  secure 
70  kv.  and  H  ma.,  suitable  for  deep  radiotherapy  or  for  fluoroscopy. 
With  a  certain  degree  of  filament  incandescence  produced  perhaps  by 
1.2  amp.  one-quarter  of  the  total  rheostat  resi>tance  may  result  in  55 
kv.  and  i-Ul  ma.,  suitable  for  radiography  of  the  extremities  and  varying 
only  the  rheostat  resistance  to  about  one-eighth  of  1  he  total  we  may  have 
t'»5  kv.  and  oO  ma.,  suitable  for  gast ro-intest inal  radiography.  And 
with  only  the  last  two  or  three  buttons  of  the  rheostat  we  may  have* 
with  the  same  filament  incandescence  produced  by  4.2  amp.  SO  kv. 
and  DO  ma.,  suitable  for  very  rapid  gastro-intestinal  radiography.  (On 
occasion  the  author  has  made  radiograph-  with  150  or  200  milliamperes 
pasHn<:-  tlirouuh  the  standard  ('oolidge  tube,  but  this  is  unwise.) 

Smt/t     M  ill i/n// j><  r<i<!<     in    Proportion    to   x-h'di/   dcncrotnni    with    the 
/i    \'<illu<i< .-    It    is   found   that    about    the   same   milliamperage 
d  to  produce  the  same  intensity  of  j-radiation  as  with  the  im- 
rrent  delivered  to  the  .r-ray  tube  by  an  induction  coil  or  by  a 
r  with  a  high-tension  rectifier.     Tins  results  in  tin1  same  heat- 
ode   and    about    the   same    number   ot    milhampere 
equal  ./'-ray  exposure?-,   the  voltage1  being  the  same1 
d    the   heating  effect    upon    the   .r-ray   tube  makes    it 
to    use  the  ( 'oolidn'c  tube,  and    if  a    series  of  body   or 
ion  to  change  to  a  not  her  ( 'oolidge 
e  with   a    tungsten   button   in  a 
irable    because    ot    a    chane    in 


THE    a'-RAY  i  OO 

jury  would  certainly  be  a  vory  severe  one.  The  author  guards  against 
such  an  occurrence  by  having  a  strong  though  thin  sheet  of  aluminum 
fastened  in  the  bottom  of  the  shield  enclosing  the  .r-ray  tube,  and,  of 
course,  by  being  careful  not  to  overheat  the  tube.  This  is  indicated  in 
the  case  of  the  standard  Coolidge  tube  by  the  anticathode  becoming 
white  hot . 

The  radiator  type  of  Coolidge  tube  may  be  run  on  this  generator 
for  a  great  many  of  these  exposures  30  ma.  or  less,  fifteen  seconds  on 
and  sixty  seconds  off. 

There  is  one  vory  marked  advantage,  however,  in  the  fact  that  the 
continuous  current  does  not  roughen  and  disintegrate  the  focus  spot 
even  with  prolonged  overheating.  The  ordinary  impulsive  current 
does  so  with  the  customary  strength  of  current. 

Radiographic  Exposures  with  the  Cabot  High-potential  Direct 
Current  Generator. — Turning  the  rheostat  to  a  point  where  only  3  or 
•\  buttons  of  the  resistance  are  still  in  series,  and  adjusting  the  ratio  of 
transformation  to  produce  90,000  volts,  an  exposure  of  one-fourth  second 
will  produce  a  radiograph  of  the  stomach  and  intestines  with  intensifying 
screen  and  radiographs  of  the  hands  without  a  screen.  A  tungsten  target 
tube  will  stand  a  number  of  these  exposures  at  intervals  of  a  second. 

Turning  the  rheostat  to  a  point  where  only  one-fourth  of  the  entire 
resistance  is  in  circuit,  and  adjusting  the  resistance  of  the  lube  for  b'0,000 
volts,  an  exposure  of  about  two  seconds  is  suitable  for  screen  radio- 
graphs through  the  body  and  about  fifteen  seconds  without  an  intensi- 
fying screen.  The  same  intensity  will  make  radiographs  of  the  extremi- 
ties in  two  to  seven  and  one-half  seconds  without  a  screen.  The  longer 
and  weaker  exposure's  have  more  effect  upon  the  vacuum  in  the  tube,  and 
require  a  change  of  tube  from  overheating  sooner  than  the  short,  strong 
exposures  which  produce  an  equal  effect  upon  the  photographic  plate. 

These  two  strengths  of  current  are  sufficient  for  many  practical  pur- 
poses in  radiography. 

The  f nt>c,  if  <j(tx  Jillcd,  /A-  /-('(juldtcd  l><  forehand  with  a  low-tension  cur- 
rent until  it  transmits  a  current  of  5  ma.  or  a  little  less  with  a  pressure  of 
about  30,000  volts.  This  may  be  done  while  the  patient  and  plate  are 
in  position,  as  the  exposure  is  so  slight  as  not  to  affect  the  picture  which 
is  made  by  turning  on  the  suitably  increased  power.  The  Coolidge 
tube  had  belter  be  regulated  before  patient,  tube,  and  plate  are  all  ar- 
ranged for  the  picture.  We  may  regulate  the  resistance  of  the  tube 
by  varying  the  filament  current  so  that  with  a  certain  power  indicated 
by  a  certain  rheostat  contact  (3  p.  M.  on  the  dial)  we  produce  (10.000 
volts  and  30  milliamperes.  Then  turn  off  the  current  and  change 
the  position  of  the  rheostat  contact  to  2  p.  M.  on  (lie  dial.  We  know  by 
many  previous  observations  that  this  will  produce  SO, 000  volts  and  an 
increased  number  of  milliamperes,  suitable  for  gastro-intestinal  radiog- 
raphy. <  )r  we  may  know  how  to  regulate  the  Coolidge  tube  without 
turning  on  the  high-tension  current,  but  simply  adjusting  the  strength 
of  the  filament  current.  For  instance.  1.2  amperes  is  about  right  for 
producing  (10.000  volts  and  30  milliampcres  with  the  rheostat  of  the  .r- 
ray  generator  at  3  p.  M.  or  70,000  volts  and  an  increased  milliamperage 
with  the  rheostat  at  2  p.  M.  It  is  not  best  to  depend  upon  placing 
the  separate  rheostat  of  the  filament  current  at  a  certain  position  if  this 
method  is  employed. 

For    rontycnothfrapy  (10,000    volt    ratio    is  excellent,  and  for  many 


75l>  MKDK'AL    KLKCTKICtTY    AND    HONTCKX    RAYS 

ruses  either  all  the  rheostat  resistance  may  be  used  or  about  nine-tenths 
of  it.  Current  values  of  57.000  volts  and  4  ma.  correspond  to  about  (> 
Benoist  and  produce  an  erythema  dose  of  5  H.  in  twenty  to  forty  min- 
utes at  a  distance  of  1M.\  inches  from  the  anlicalhode  to  the  skin. 

A  new  gas-filled  tube  will  commonly  light  up  at  a  tension  of  20  kilo- 
volts  and  pass  a  few  milliamperes.  After  a  little  use  it  may  require 
40.000  volts  and  pass  5  ma.  The  tube  in  the  first  condition  will  pass 
perhaps  200  ma.  if  sufficient  power  is  turned  on  to  maintain  a  tension  of 
!»0  kilovolts  at  tin  tube  terminals,  while  in  the  second  condition  a  voltage 
of  00.000  will  send  perhaps  only  about  30  ma.  through  the  tube. 

A  tube  which  has  been  used  a  number  of  times  requires  a  higher  and 
higher  voltage  to  light  up  and,  unless  the  vacuum  is  regulated,  will 
eventually  reach  the  crank  stage,  where  100.000  volts  may  be  required 
to  break  down  the  resistance  of  the  tube,  and  where,  with  an  unfluctua- 
ting voltage  generator,  a  great  rush  of  current  may  take  place  with  an 
undesirable  effect  upon  the  tube.  The  moral  is  to  test  the  condition  of 
thi'  tube  with  small  current  values  and  use  the  regulator  rather  than 
extremely  high  voltages  for  overcoming  crankiness. 

The  time  of  exposure  with  any  of  these  voltage's  will  lie  shorter 
the  greater  the  number  of  milliamperes  passing  through  the  tube.  The 
best  current  with  medium  and  high  voltages  is  20  to  50  milliamperes. 

Within  reasonable  limits  it  may  be  said  that  with  any  particular 
voltage  or  penetration  factor  the  same  number  of  milliampere  seconds 
will  produce  the  same  radiographie  result. 


3")  to  40  kv.     For  great  contrast  in  general  work  and  not  too  thick  region!5. 

40  to  4")  kv.  For  bone  work  where  thickness  of  tissue  is  under  2  inches,  for  chest 
work  on  100-pound  subjects,  and  for  general  tissue  detail  using  tin 
intensifying  screen. 

4.1  to  ."iO  kv.  Suitable  tor  bone  work  on  the  extremities  and  chest  work  on  1~>0- 
pound  subjects. 

"0  to  HO  kv.  Best  for  kidney  work  on  light  Mibjeets.  May  be  used  for  bismuth 
work  on  light  subjects.  Hood  for  general  bone  work  on  the  extrem- 
ities. 

tin  to  70  kv.     Same  as  above  with  increasingly  heavy  subjects. 

TO  to  SO  kv.  Only  suitable  for  hip.  frontal  .-inus.  all  bi.-muth  work  unless  contrast 
between  details  is  unnecessary. 

Mv  own  best  results  are  obtained  with  55  kv.  as  the  lowest ;  for  teeth, 
except  upper  molars;  for  fin  tiers;  with  (>5  kv.  for  kidney,  gall-bladder,  and 
general  bone  and  lung  work;  and  with  SO. 000  volt-  for  Castro-intestinal 

a nd  | nit'iima*  K-  -mil-  work. 

I'.. i'n rn /ill  .->•  nt  li'nfl  i/>ii/'<i /i/i  ic  hxiHixin'cv  n'ltli  an  (  >/ fluct unfitly  \  oltotjc. 
A  -mal!  <-!iild'-  hand  may  be  radiographed  with  50  kv..  the  thymus 
Lrland  with  till  kv.;  a  thin  adult  fool  with  n'5  kv.  and  MO  ma.  exposure, 
three  seconds  at  2s  inche.-.:  a  laru'er  ISO-pound  woman's  abdomen  with 
'is  kv.,  10  ma  ..  and  five  or  six  second-.  l'i-mut  h  expo-lire-  are  made  with 
so  kv.,  Mil  nia..  an  ml  en-it  ymg  screen,  and  an  expo-ure  of  one  -econd  or 
more,  ilep  'ndiim  upon  the  -i/e  of  ;he  person.  A  very  thick  adult  hip 

rei  mire-   si  i  i  H  H  i   \-{  ,||  <_ 

I  he  "fhioro-ropic  at  tachment ."  by  means  of  which  t  he  current  passed 
throuirh  the  .  -ray  tube  onl\"  one-tenth  of  the  total  time  of  expo-tire,  ac- 
coinpli-hed  •  tnore  than  the  mere  attenuation  of  the  radiance.  It 


THE    X-RAY  <o7 

made  it  possible  to  decidedly  increase  the  voltage,  and,  consequently, 
the  penetration,  without  increasing  the  milliamperage  or  the  total  x- 
radiance  to  which  the  patient  was  exposed  in  the  course  of  a  treatment  or 
a  tluoroscopic  examination.  This  lias  been  discarded,  as  all  these 
desiderata  are  easily  obtained  with  the  Coolidge  tube. 

The  tube  in  a  certain  condition  may  transmit  5  ma.  with  a  voltage 
of  40,000  and  an  all-time  current,  and  show  current  factors  of  2  ma.  and 
54  kilovolts  with  one-tenth  time  current.  This  means  an  increase  of 
almost  one-half  in  penetration  and  deep  effect  in  radiotherapy  and  safety 
in  fluoroscopy. 

Sabouraud  Dose  of  About  51  H.  iritJi  the  Cabot  Transformer. — Cabot 
and  Dodd,  experimenting  at  the  Massachusetts  General  Hospital,  found 
that  with  a  penetration  of  4  Benoist  this  standard  erythema  dose  was 
applied  by  an  exposure  of  3400  milliampere  seconds  at  a  distance  of  10 
inches  from  the  anticathode  to  the  skin.  For  example,  a  current  of  3T\ 
ma.  would  require  an  exposure  of  one  thousand  seconds,  and  an  exposure 
of  two  thousand  seconds  with  1 T70  ma.  and  five  hundred  seconds  with  6yV 
ma. 

My  own  observations  go  to  show  that  milliampere  seconds  do  not 
form  a  reliable  measurement  of  x-ray  dosage,  but  that  it  is  necessary  to 
standardize  the  conditions  as  to  voltage  and  milliamperage,  so  that 
these  may  be  duplicated  for  each  treatment  of  the  same  character  with 
the  same  x-ray  tube;  and  then,  by  means  of  a  record  of  the  effects  upon 
patients  or  test  exposures  upon  Sabouraud  pastilles,  or  the  author's 
method  of  comparing  the  photographic  effect  of  the  x-ray  with  that  of 
incandescent  electric-light,  we  may  attain  an  accurate  measurement  of 
the  power  of  the  x-radiance  itself. 

Absorption  of  x- Rays  of  Different  Degrees  of  Hardness  by  the  Human 
Tissues. — Cabot's1  results  with  an  unfluctuating  voltage,  shown  in  the 
table  below,  agree  with  my  own  with  both  fluctuating  and  unfluctuating 
voltages,  but  with  given  readings  of  the  Benoist  radiochromometer,  1 
Benoist  for  each  10  kilovolts. 

Voltage  on  tube  terminals.  Thiokne??  (inohesi  of  tissue 

Kilovolts.  absorbing  90  per  cent,  of 

x-ray. 

w "...  if 

40 2| 

•><> 2f 

00 3J 

70 3f 

NO 4| 

«>() 4* 

100 ol 

X-ray  Tube  l\efushi<j  to  Transmit  Currnit. — One  important  fact  is 
that  a  tube  which  will  not  light  up  with  any  reasonable  application  of 
power  in  the  form  of  an  unfluctuating  voltage  may  very  likely  light 
up  under  the  impulsive  discharge  from  an  induction-coil,  and  imme- 
diately afterward  operates  nicely  with  the  unfluctuating  voltage.  The 
possession  of  even  a  small  induction-coil,  and  its  use  for  such  contingencies, 
will  often  save  a  tube  from  being  punctured  or  having  its  vacuum  reduced 
below  a  useful  limit  in  the  effort  to  pass  a  current  of  unfluctuating  volt- 
age through  it.  these  remarks  apply  also  to  the  use  of  the  ordinary 
1  Arc-hives  of  the  Kimtin-n  Kuv,  AUK.,  1"1 1- 


7o8  MEDICAL    KLKCTRICITY    AND    KO.NTGF.X    HAYS 

spark  regulator  for  lowering  (he  vacuum  in  the  tube:  it  is  sometimes  diffi- 
cult to  scud  an  unfluctuating  voltage  current  through  the  regulator  of  a 
cranky  tube. 

It  is  not  to  be  supposed,  however,  that  such  troubles  are  entirely 
avoided  by  the  mere  use  of  an  induct  ion-coil  or  of  a  transformer  giving 
an  impulsive  current.  There  comes  a  time  with  every  gas-filled  tube 
when  a  further  attempt  to  send  a  current  of  any  kind  through  it  will  re- 
sult in  ruin.  The  tube  should  not  be  forced,  but  sent  to  the  maker  to 
have  a  new  regulator  applied  and  re-exhausted.  The  author  has  had 
one  ( 'oolidge  tube  get  into  this  condition  after  a  great  deal  of  hard 
service. 

An  apparatus  designed  by  Hull  and  depending  upon  the  use  of 
transformers  and  condensers  has  been  made  by  the  ( leneral  Electric 
Company,  and  t  heir  observations  show  that  t  he  unidirectional  unvarying 
high-tension  current  has  the  advantage  of  producing  much  less  rough- 
ening of  t  he  focus  spot  and  t  hus  prolonging  th"  life  of  t  he  ( 'oolidge  1  ube. 
Thi-  is  confirmed  by  my  own  experience  with  the  Cabot  generator. 
They  found  that  t  he  .f-ray  s  pec  t  rum  was  t  he  same  as  t  hat  of  the  ordinary 
transformer  with  a  high-tension  rectifier.  This  does  not  confirm  my 
hope  in  regard  to  securing  homogeneous  .r-ravs.  They  report  that  a 
tunii'sten  target  produces  very  much  the  same  spectrum,  regardless 
of  momentary  fluctuations  of  voltage.  They  also  found  that  the  milli- 
amperau'e  at  a  certain  voltage  was  less  than  was  required  to  produce 
the  same  ./'-ray  effect  with  a  transformer  and  rectifier.  This  contributed 
to  the  preservation  of  the  anticathode. 

Potrer  factor  is  the  ratio  of  true  watts  to  apparent  watts  in  an  al- 
ternating current  circuit.  When  there  is  only  ohmic  resistance  in  the 
circuit  1  he  power  factor  is  lor  100  per  cent .  Inductance  always  reduces 
the  power  factor.  For  example,  some  transformers  for  re-ray  generation 
have  a  power  factor  of  about  50  per  cent .  and  ot  hers  of  about  75  per  cent . 
It  is  not  necessarily  the  case  that  the  transformer  with  the  highest  power 
factor  excites  an  ./:-ray  tube  best.  It  is  true  with  the  Henifar  self-rectify- 
ing 1  ube. 

THE    TYPE    OF  TUBE 

When  an  x-ray  tube  is  spoken  of  as  a  50-rw.  tube  it  means  that 
the  tube  is  intended  for  use  with  a  current  strong  enough  to  spark 
across  a  space  of  50  cm.,  and  for  general  radiographic  work  this  is 
about  the  best  si/e  of  tube  to  use.  A  tube  of  25-cm.  rating  is  about 
the  smallest  useful  size,  and  one  as  large  as  100  cm.  is  to  be  considered 
as  a  curiosity.  Recently  tubes  have  been  designated  as  7-inch  bulbs 
if  t  heii-  diameter  is  7  inches,  and  this  is  the  most  useful  si/e.  The  bulb 
of  a  50-cm.  tube  is  about  (i  inches  in  diameter  and  t  he  distance  from 
the  cathode  to  the  anticathode  is  about  o  inches,  and  usually  the  anode 
and  anticathode  are  connected  by  a  wire  outside  the  tube,  so  that  the 
anticathode  i-  also  an  anode.  The  resistance  to  the  passage  of  the 
current  throuuh  the  tube  i-  very  slight  when  the  vacuum  is  low  and  al- 
most any  strength  of  current  may  be  sent  through  it,  but,  of  course, 
not  lontr  enough  to  overheat  the  tube.  When  the  vacuum  is  medium, 
however,  the  resistance  is  such  that  if  a  current  of  more  than  a  suitable 
strength  i-  turned  on  only  a  portion  of  the  current  can  be  carried  across 
by  the  cathode  -tream  and  the  rest  will  spark  across  the  air-space  be- 
tween the  positive  and  negative  tips  of  the  tube  with  verv  great  danger 
of  punct  urn  in  the  1  ube.  This  is  the  wa  v  t  ha  t  most  punct  ures  occur,  t  he 
spark  pas-'mu:  perhaps  from  the  negative  tip  toward  the  anticathode, 


PL  ATK    10 


THE    £-RAY  759 

penetrating  the  glass  in  its  attempt  to  effect  the  discharge  along  the 
shortest  path.  Of  course,  other  punctures  occur  from  allowing  one 
of  the  conducting  cords  to  hang  too  near  the  bulb,  and  it  is  partly  to 
avoid  this  possibility  that  the  various  points  of  an  .r-ray  tube  are  made 
so  long.  A  tube  in  which  the  vacuum  is  very  high  would,  of  course,  be 
sure  to  punct  are  if  a  powerful  current  were  t  urned  on.  With  any  suitable 
degree  of  vacuum  a  oO-cm.  tube  will  transmit  the  discharge  from  any 
of  the  coils  or  static  machines  ordinarily  used  for  x-ray  work,  but.  of 
course,  a  LM-cm.  tube  would  not  stand  the  full  current.  Some  tubes  are 
liable  to  become  hard  or  develop  a  high  degree  of  vacuum  during  the 
exposure,  and  it  is  often  wise  to  have  the  positive  and  negative,  arms 
of  the  .r-ray  coil  only  a  little  farther  apart  than  the  spark  resist- 
ance of  the  tube  so  as  to  act  as  a  safety  valve.  If  the  vacuum  in 
the  tube  and  consequently  its  resistance  become  too  high,  the  cur- 
rent will  then  leap  across  between  the  terminals  of  the  coil  instead  of 
puncturing  the  tube.  The  same  safety-valve  arrangement  is  almost 
always  a  wise  precaution  against  accident  in  the-  event  of  an  excessive 
current  from  burning  out  or  short  circuiting  some  part  of  the  rheostat. 
In  such  a  case  if  the  current  can  harmlessly  jump  across  a  space  of  o  or 
4  or  even  •">  or  S  inches  between  the  arms  of  the  coil  it  may  prevent  injury 
to  the  lube  and  alarm  to  the  patient. 

The  most  satisfactory  gas-filled  tubes  are  the  bianodal,  in  which  the 
anticathode  and  the  anode  may  be  connected  by  a  wire  outside  the 
bulb  and  really  form  a  double  anode.  Such  a  tube  does  not  blacken 
as  quickly  as  one  in  which  there  is  only  one  anode,  and  this  feature  is 
especially  valuable  while  the  tube  is  being  exhausted  on  the  air-pump. 
It  must  be  remembered  that  a  gas-filled  .r-ray  tube  consists  essentially 
of  a  bulb  containing  a  partial  vacuum  with  a  positive  and  a  negative 
wire  carrying  to  it  a  current  of  very  high  potential  and  very  rapid  inter- 
ruption-. The  current  is,  of  course,  said  to  be  carried  from  the  positive 
to  the  negative  pole,  no  matter  what  their  relative  positions  may  be: 
but  as  a  result  of  the  current  the  cathode1  rays  start  perpendicularly 
from  every  point  on  the  front  of  the  cathode1,  which  is  commonly 
made  concave  so  as  to  focus  these  rays  upon  a  metal  disk  called  the  anti- 
cathode,  where  their  impact  causes  the  vibrations  called  the  .r-ray.  It 
is  not  necessary  that  the  anticathode  should  be  connected  in  any  way 
with  the  electric  current.  In  fact,  in  some  tubes  used  especially  for 
treatment  there  is  no  anticathode  .at  all,  the  .r-ray  originating  from  the 
impact  of  the  cathode  stream  upon  the  glass  wall  of  the  tube.  This  was 
originally  the  case  in  all  .r-ray  tube's.  The  essential  functions  of  the 
target  are  so  distinct  from  those  of  the  anode,  which  is  merely  the 
positive-  terminal,  that  it  is  always  preferable-  to  call  it  the  anticathode. 
In  some  tubes  it  forms  also  the  only  anode1,  and  in  others  it  may  be1 
used  jointly  with  another  anoele1.  or  may  be1  usexl  as  the1  only  anode, 
or  may  be  entirely  elise'emnevted  from  the  e'lectric  wire's.  The1  anti- 
cat  he>de  in  any  e-ase  must  be  plac.ed  at  the  focus  eif  the1  cathoele  mirror: 
the  anode,  howeve-r,  may  be1  placed  at  any  part  of  the1  tube  at  a  sufficient 
distance-  from  the  cathoele.  Sometimes  it  will  be-  found  that  a  new  tube1 
has  quite  a  low  vacuum  and  will  give1  better  results  when  the1  anode-  and 
the  anticathode1  are1  disconnected  and  the1  connection  made  only  with  the1 
anticathode'.  As  a  tube-  become-s  harder  fremi  use1  it  will  often  be1  found 
desirable  to  comuM't  the1  anode1  ami  the  anticathode.  This  point  is 
of  some1  practical  importance,  but  it  will  be1  founel  not  te>  be1  of  use1  in  all 
tubes. 


/()()  MKIMCAL    KLKCTHICITY    AM)    RONTGEN    RAYS 

A  very  important  fact,  however,  is  that  the  use  of  the  anode  alone 
will  frequently  induce  the  proper  production  of  the  .r-ray  in  a  tube  which 
is  behaving  badly.  The  latter  may  be  due  to  an  excess  of  inverse1  dis- 
charge. In  the  author's  hands  this  lias  been  most  strikingly  illustrated 
in  the  case  of  a  heavy  anode  (iundelach  tube  of  S()-cm.  rating,  in  which 
no  amount  of  regulation  of  the  vacuum  or  of  the  self-inductance  or  of 
the  interruptions  or  strength  of  the  current  succeeded.  There  was  an 
irregular  green  light  which  almost  filled  the  tube  with  flickering  circles 
here  and  there  and  a  very  poor  .7'- ray  was  shown  by  the  iluoroscope. 
This  was  all  immediately  remedied  by  disconnecting  the  anticathode 
and  using  only  the  anode  for  the  positive1  terminal,  and  the  tube  became 
sharply  divided  into  a  dark  hemisphere  and  a  hemisphere1  fillenl  with 
brilliant  steady  gtve'n  light  with  a  goeul  .r-ray  production.  After  sue'h 
a  tube  has  begun  to  work  properly  the'  aimde  and  anticathode  may  be 
founel  to  work  very  nice'ly  when  reconnected.  As  intimated  above,  there 
are1  several  either  causes  and  as  many  re'menh'e's  feir  this  troublesome 
condition,  so  that  this  disconnection  of  the  anticathode  is  ne>t  always 
the1  thing  neeeled. 

The  line  of  demarcation  in  an  .r-ray  tube'  may  be'  displaced  forward 
by  introducing  a  spark-gap  in  the  e-ircuit.  Charbonneau,1  who  called 
aTtentiem  to  this  fact,  finels  that  the  displacement  is  the  same-  for  any 
length  of  spark  freun  ^  mm.  up.  He'  finels  the  same'  amemnt  of  dis- 
placement, no  matter  whether  the  spark  is  on  the  line  leading  to  the 
ane>de-  or  the-  e-athoele-  of  the'  tube-. 

Charbonneau  finels  that  the-  elegreo  of  penetration  is  reeluced  33  per 
e-ent.  by  any  spark-gap,  however  short,  em  e-ithe-r  line. 

A  ]>erfecTly  continuous  connection  must,  theTefore-,  be  made  without 
the'  smallest  spark-gap  between  the'  peile-s  of  the  .r-ray  coil  in  oreler  to 
se-e-ure  the-  maximum  fie'lel  anel  the-  maxijnum  peiwer  of  radiation. 

Charbonneau  attributes  this  ei'fect  in  part  te>  the  entrane-e1  e>f  hydro- 
gen intf)  the  .r-ray  tube  by  electric  ine-ans.  The  hydrogevn  is  supposed 
to  arise-  freim  the  e'lee-trie-  decomposition  of  wate-ry  vapeir  prese'iit  in 
the  atmosphere.  He' puts  this  To  practical  use  in  reducing  the1  vacuum 
in  an  .r-ray  tube  which  has  ne>  regulateir.  The  connections  are  maele 
in  the  regular  way  e-xe-e-pt  that  the-re  is  a  small  spark-gap  on  the  line' 
leading  to  one  pole  of  the-  ce>il.  A  moderate  e-urrent  allowed  to  flow 
through  the  tube  for  half  an  heiur  results  in  a  material  reduction  in  the' 
decree  of  vacuum  as  indicated  by  the-  spintremeter  and  the  Benoist 
ttidiochrornometor. 

The  ''hi-avi/  anode"  (meire  properly  "heavy  anticathode")  (1  mid  cinch 
1'ihc  was  an  excelle'nt  erne,  the  glass  being  eif  the  very  best  quality  fe>r 
r-nty  work,  the-  eismo-re-gulator  being  first  class,  and  the1  anticathode 
being  shaped  like  a  horse's  hoof  and  presenting  such  a  large  mass  of 
metal  as  to  stand  the  heaviest  curre-nt  without  fusing.  ( Fig.  1X1  shows 
Then-  is  no  perfect  r-ray  tube,  however,  and  one1  of  the1 
this  tube  was  that  the  shadow  of  the  anticathode  was 
dire-die)!!  in  which  the  picture'  is  gene-rallv  taken.  This 
•  fact  that  the  anode  was  placed  behind  the  anticathode, 
1  other  tube-,  the  anode  was  in  the  lon<j;  axis  ()f  the  tube1 
the  anticathode  extended  backward  so  that  the  shadow 
e  did  not  fall  in  front  with  lhe>e  other  tubes.  Another 
hared  by  all  "heavy  anode  '  gas-filled  tubes;  the  great 
l.<  !;,-i. lium.  Si -ptcmlxT  I.",.  1  <«>.-,. 


THE    0--KAY 


701 


mass  of  metal  liberated  so  much  gas  when  overheated  that  the  tube  be- 
came temporarily  useless  the  moment  it  got  very  hot.  Some  of  the 
author's  best  radiographs  were  made  with  a  00  cm.  tube  of  this 
type,  but  it  seemed  to  him  that  this  type  of  tube  was  a  little  more 
difficult  to  use  than  some  others.  If  it  was  not  in  just  the  condition  re- 
quired, it  required  all  the  skill  and  patience  one  possessed  to  adjust  it.  It 
has  an  osmo-regulator.  a  thin  metal  tube,  usually  of  palladium,  looking 
like  a  win1,  which  when  heated  by  an  alcohol  lamp  permits  hydrogen 
gas  to  pass  through  its  pores  and  thus  lowers  the  vacuum  (Fig.  482). 


Fig.  481. — Gundelach  heavy  anode  tube. 

Hanging  a  cuff  of  platinum  over  the  osmo-regulator  enables  one  to  raise 
the  vacuum  (Fig.  483).  For  this  purpose  a  loose  cuff  of  platinum  is  put 
over  the  platinum  tube  and  is  heated  on  the  outside  by  an  alcohol  flame. 
The  heat  must  be  intense  enough  to  make  the  inner  as  well  as  the  outer 
tube  red  hot  and,  consequently,  porous  to  hydrogen  gas.  The  excess  of 
gas  in  the  .T-ray  tube  escapes  through  the  pores  in  the  small  red-hot 
platinum  tube. 

A  special  lamp  for  heating  an  osmo-rcgulator  has  been  devised  by 
Paquelin,  the  inventor  of  the  celebrated  thermocautery  which  bears  his 

name.  By  an  arrangement  of  hand- 
bulb  and  container  full  of  naphtha, 
"benzene,  or  gasolene  a  jet  of  carbu- 
retted  air  may  be  ignited  and  when 


Fit 


4S2.—  Villard's  osmo-regulator  lowering 
the  decree  of  vacuum. 


Fig.  -4 S3. — Raising  the  degree  of  vacuum. 


directed  against  the  osmo-regulator  produces  the  desired  effect  very 
rapidly.  As  in  the  case  of  the  cautery,  the  lamp  remains  in  full  blast  as 
long  as  the  current  of  air  is  kept  up  by  squeezing  the  hand-bulb.  It  is 
very  important  never  to  lower  the  vacuum  to  too  great  an  extent.  If 
the  vacuum  is  only  a  little  too  low  it  can  readily  be  brought  up  by  run- 
ning the  tube  for  a  few  minutes  with  a  reversed  current.  A  tube  in 
which  the  vacuum  lias  become1  too  low  from  overheating  bv  the  cur- 


<»>_:  MKDICAL    KLKCTR1CITV    AND    KONT(iKN     HAYS 

rent  usually  returns  to  its  original  condition  if  simply  allowed  to 
cool,  and  can  hardly  be  made  to  do  so  in  any  other  way.  The  "heavy 
anode"  (lundelach  tube  cooled  quickly  and  regained  its  original  decree 
of  vacuum  very  well.  It  seemed  to  be  better  adapted  for  radiography 
than  for  treatment,  and  would  stand  a  secondary  current  produced 
by  o()  ampere-  of  primary  current.  Il  would  have  been  at  that  lime  the 
author'-  first  choice  for  radiography  if  it  were  easier  to  keep  in  order. 
A-  the  vacuum  was  very  likely  to  fall  after  a  long  exposure  it  was  neces- 
sary to  have  two  tubes  if  difficult  pictures  were  to  be  made  in  rapid  suc- 
ce--i<  in. 

The  "I'l/ltt  <iiiiiil<"  Gundclnch  tube  was  one  of  the  best  of  its  kind  and 
wa-  all  r'mht  for  the  lighter  work  in  radiography,  such  as  a  picture  of 
non-union  after  fracture  of  the  radius  and  ulna.  It  had  the  osmo- 
regulator.  This  tube  did  not  lose  its  decree  of  vacuum  like  the  ''heavy 
anode"  tube  and  could  be  run  for  pictures  or  treatment  with  the  anti- 
cathode  red  hot.  ('are  had  to  be  taken  not  iO  burn  a  hole  through  the 
platinum  disk  by  overheating. 

T  n  mjsli  n  T<II'<!<  f  x-L'/ii/  T/il/t  .s.—  The  author's  tendency  i-  to  use  "heavy 
anode"  tube-  altogether  for  radiography  and  radiotherapy,  and  since 


it-  di-cnvery  the  tuttr/*t<n  (ti/'ijif  has  been  exclu-ively  ado])ted.  Tung- 
sten ha-  a  melting-point  twice  a-  high  as  thai  of  plat  in  inn.  and  if  the  anti- 
cathode  consists  of  about  .',  pound  of  copper  into  the  face  of  which  a 
button  of  tunii-ten  is  electrically  welded  it  is  pract ically  indestructible. 
\  ej-y  satisfactory  lubes  of  this  kind  ai'e  to  IK-  had  from  any  of  the 
American  .r-ray  tube  nianufacturers.  They  should  have  a  regulator  for 
re'  lurinu  i  he  degree  of  vacuum. 

Tubes  with  t  he  type  of  regulator  found  on  t  his  one  may  be  Used  with 
the  regulator  so  adjusted  that  the  wire  of  the  reducer  is  a  measured  dis- 
tance  from  the  negative  tip  i  Fig.  1S.~>>.  A  portion  of  the  current  will 
leap  aero--  thi-  -pare  if  the  re-i-taiice  in  the  tube  ri-es.  and  in  this  way 
tra-  u'ill  lie  liberated  and  the  vacuum  reduced.  Acting  a-  an  automatic 
governor,  i  hi-  will  prevent  the  vacuum  from  ri-ing  above  the  level  de- 
termined by  the  ilistaiice  at  which  the  wire  i-  placed.  For  radiography 

-   better  not  to  allow  the  regulator  to  act  automatically. 

A  -mall  pleiluct  of  cotton  moistened  with  water  i-  employed  in  the 
regulator  of  M  tube  recently  constructed  by  l)ean.  of  London,  and  Ber- 
lemot.  of  1'ari-  V\<^.  }^H  .  The  regulator  i-  a  separate  portion  of  the 
/-ray  tube  with  which  M  communication  is  established  by  turning 


T1IK    .T-KAY 


763 


a  stop-cock.     Watery  vapor  from  a  \vct  sponge  in  the  small  prolongation 
then  enters  the  main  hull)  and  lowers  the  decree  of  vacuum. 


Water-cooled  tube*  have  been  made  by  Gundclach,  Miiller,  and 
others  in  ( lennany,  by  Machlett,  of  \e\v  York,  and  by  Friedlander.  of 
(Jermanv  and  Chica.no.  In  them  there  is  a  water-vessel  (Fin;.  4S7 ' 


designed  more  or  less  perfectly  to  prevent  the  anticathode  from  becom- 
ing too  hot.  In  the  original  Friedlander  water-cooled  tube  the  water 
surrounds  the  heavy  copper  stem  of  the  anticathode,  but  the  heat 


<t)4  MKDICAL    KLK(  THH'ITY    AND    KoNTOKN    KAYS 

reaches  the  water  so  slowly  that  it  affords  very  little  protection  in  the 
case  of  short  exposures  with  a  heavy  current.  This  particular  tube  has 
quite  a  heavy  target,  however,  and  retains  its  vacuum  quite  well.  Some 
of  my  best  radiographic  work  has  been  done  with  it.  The  theoretically 
correct  water-cooled  tube  is  one  in  which  the  target  forms  the  bottom 
of  the  water  chamber.  It  has  been  found  that  it  is  better  to  have  the 
disk  or.  rather,  cup  itor  it  forms  the  whole  lower  section  of  the  anti- 
cathode)  made  of  thin  platinum  wit  ha  backing  of  nickel  a  in  1  to  have  a  met- 
allic stem  pass  from  it  to  the  positive  tip  of  the  tube.  A  heavy  pure  plat  i- 
n  u  in  ant  i  cathode  absorbs  so  much  gas.  like  spongy  plat  i  num.  that  the  vac- 
uum becomes  too  high :  and  water  is  too  poor  a  conductor  to  give  the  best 
results  without  a  complete  metallic  connection.  Tubes  on  this  principle 


Fip.  4s~. — Water-cooled  .r-ray  tube  of  the  Muller  type. 

arc  made  by  all  the  firms  mentioned  above,  they  are  expected  to  stand 
the  heaviest  currents,  and  when  in  working  order  produce  beautiful 
pictures.  They  are  so  difficult  to  keep  in  the  best  condition,  however, 
that  at  the  present  writing  they  seem  hardly  to  be  recommended. 

<  >ther  tubes  are  made  in  which  the  reduction  of  vacuum  is  produced 
by  heating  a  prolongation  containing  potash  or  by  passing  a  spark 
through  it.  In  Thompson's  automatic  regulating  tube  this  spark  passes 
to  the  \vire  which  leads  into  the  prolongation  containing  the  potash 
whenever  the  vacuum  reaches  a  certain  degree  of  resistance,  as  deter- 
mined by  the  distance  at  which  the  wire  is  placed. 

The  VnH-Olun  tuht.  has  the  secondary  anode  in  a  bulbous  expansion 
•  if  the  positive  prolongation  of  the  tube.  It  i.-  made  \vith  or  without  a 
.-emulator  and  the  latter  may  be  set  to  act  automatically.  It  is  also 
made  \vith  different  weights  of  anticathode  and  is  in  every  way  a  lirst- 

'•:;i~-  t  ube. 

The  l,nrin  rnnnitn  tuhi  has  the  spark-.irap  lending  to  the  regulator  en- 
\<>"  >\  in  Lard  rubber  to  conceal  the  spark  and  reduce  the  noise,  and  it 
K-  -<  •  to  :t''t  automatically  at  anv  decree  of  vacuum. 

•  i  in  -  are  made  with  a  valve  arrangement  by  which  air  may  be 

'  •  •  •  vacuum  1< i\verei  1. 

•  i  •  •       I  Vied  lander)  are  made  with  an  adjust  able  focus  operated 

•    •  itn    !)•,•  means  ot  a  horseshoe  magnet.      A  heavy  cur- 
:    verv  small  spot  will  fuse  the  platinum,  while  tins 
•    :  lie  i'<  icus  were  less  sharp. 


THE    X-KAY 


7<>r> 


structed  on  the  same  principles,  but,  as  will  be  seen  from  the  illustration, 
on  a  little  different  lines  from  the  retaliating  tubes  of  Friedlander  and 
Miiller. 

Tubes  made  with  an  automatic  regulator,  as  patented  by  Queen   A: 
Company,  may  be  run  continuously  for  a  long  time,  providing  tliut  the 

tube  has  a  tendency  either  not  to  change  in  vacuum  or  to  change  slowly 
toward  a  higher  decree  of  vacuum  with  the  strength  of  current,  that  is 
employed.  The  regulator  is  set  at  such  a  point  that  a  spark  will  leap 
across  to  it  if  the  resistance  of  the  tube  increases  in  consequence  ot  the 
change  to  a  higher  decree  of  vacuum.  The  spark  causes  a  generation  ot 
gas  in  the  tube  and  lowers  the  vacuum  to  the  proper  decree.  Then- 
is  a  certain  loss  of  radiance  during  the  action  of  the  automatic  regulator. 
This  must  be  taken  into  account  in  estimating  the  exposure.  Five 
seconds  is  the  proper  time  for  certain  pictures,  but  this  would  not  be 


with  interior  filter.     An  abandoned  model. 


long  enough  if  a  powerful  spark  were  leaping  across  to  the  automatic 
regulator  all  that  time. 

Helium  (las  in  x-Raij  Tubes. — The  mineral  cleveite  if  purified  over 
calcium  and  carefully  dried  gives  out  helium  gas  when  heated. 

The  purest  channel  rays  or  positively  charged  particle*  are  obtained 
in  a  Crookes'  tube  containing  practically  pure  helium  gas. 

Snook  has  patented  an  x-ray  tube  in  which  the  regulator  consists  of 
a  portion  of  cleveite  which,  when  heated  by  passing  a  spark  through  it, 
liberates  helium  and  so  lowers  the  degree  of  vacuum.  The  claim  is 
made  that  such  an  .r-ray  tube  possesses  the  property  of  giving  out  rays 
of  a  higher  degree  of  penetration  with  the  same  medium  resistance  and 
other  electric  constants  than  tubes  which  contain  other  gases.  The 
author  has  not  been  able  to  note  very  much  difference,  but  the  tube  is  an 
excellent  one. 

A" -re///  tubes  with  on  interior  filter^  are  provided  with  an  arrange- 
ment for  arresting  the  cathode,  soft  .r-ray.  and  secondary  rays.  It 
allows  the  exit  of  only  the  direct  x-rays  which  radiate  from  the  point 
of  impact  of  the  cathode  stream  upon  the  anticathode  i  Fig.  4Ss>. 

1  J.  Koscntluil,  I'hvs.  Zt'it.,  No.  1-',  1900. 


7t)()  MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

Secondary  rays,  however,  arise  from  the  glass  wall  of  the  tube  between 
the  points  marked  .r  and  .r.  This  model  has  been  abandoned. 

A -ray  tubes  have  been  made  by  Yillard  in  1MI7.  and  Herlemont  in 
J'.H>7.1  in  which  an  acc<  xxori/  electrode  of  aluminum  or  magnesium  is 
used  to  reirulate  the  deirree  of  vacuum.  The  vacuum  is  lowered  by 
connecting  the  accessory  electrode  with  the  anticathode.  It  is  raised  by 
connecting  the  accessory  elect  rode  with  the  cathode  and  using  a  weak 
"urrent.  Yillard  abandoned  the  idea  because  the  absorption  or  liberation 
of  molecules  of  gas  was  not  abundant  enough  for  practical  purposes. 

High-frequency  ,r-Ray  Tubes. — The  tube  referred  to  may  not  be 
entirely  original  with  Machlett  A:  Son  of  New  York,  but  they  have  made 
it  so  that  it  gives  very  good  results.  The  new  feature  is  the  construction 
of  the  accessory  anode  in  the  form  of  an  aluminum  concave  mirror  like 
the  cathode,  but  not  quite  so  large.  Cathode  rays  arising  from  this 
accessory  anode  are  focused  into  a  funnel  upon  the  back  of  the  anti- 
cathode  which  prevents  the.r-rays  produced  by  inverse  discharge  from 
reach  in  ir  the  field  to  be  radiographed.  The  accessory  anode  may  be  used 
as  the  only  positive  terminal  of  the  tube  with  the  expectation  that  most 
of  the. r-ray  from  inverse  discharge  will  be  suppressed.  This  arrange- 
ment makes  the  tube  work  excellently  with  a  direct  current  induction- 
coil  which  is  giving  a  irreat  deal  of  inverse  discharge  and  also  with  a 
Te-la  or  high-frequency  transformer  which  gives  practically  an  alternat- 
ing secondary  current.  The  tube  so  connected  may  he  used  with  a  ('aid- 
well  interrupter  upon  the  alternating  electric-light  circuit.  The  tube  has 
no  valve  effect  tending  to  suppress  inverse  currents.  The  author's 
u-e  of  this  tube  has  been  with  a  12-inch  induction-coil,  AYehnelt  interrup- 
ter. 1  ID-volt  direct  cu'/renl.  Is  amperes  primary  current .  and  with  such 
a  decree  of  vacuum  that  the  secondary  current  is  s  milliamperes.  Both 
the  accessory  anode  and  the  anticathode  are  connected  with  the  posi- 
tive wire  from  the  induction-coil.  The  exposure  for  a  radiograph  of  a 
hand  or  of  the  teeth  at  a  distance  of  1<»  inches  from  the  anticathode 
to  The  plate  ;.-  five  seconds  or  less;  and  tor  the  anteropo.-tenor  radiograph 
of  the  frontal  sinus  at  a  distance  of  2">  inches  the  exposure  is  thirty 
seconds.  The  latter  exposure  is  correct  tor  the  abdomen  or  hip.  but  is 
somewhat  Too  long  for  the  chest.  \Yith  the  tube  in  this  condition  we 
find  that  the  fir-i  fifteen  seconds  are  characterized  by  the  presence  of  a 
-teady  apple-green  fluorescence  and  a  sharp  dividing  line  m  the  tube. 

After  the  first  fifteen 
-eiice  ol  an  inverse 
o.-es  it  -  .-harp  dividing 
verv  effect  i  ve  j'-rav  is 


charge  would  produce  a  very 


the  radiograph   if  a  diaphragm   and  cylinder  wer 


or  two  and   in 
required  it   will 

the  current  at  the  end  ot  tnteen  seconds  and 
inder  of  the  exposure  later.  The  author  does  not 
irt  to  the  varioii-  devices  u.-ed  to  .-uppress  the  in- 
as  -park-gaps  and  ventnl  tube-. 

t  ube    i-  of    t  he    type   of    1  he 
i-  a   heavy  piece  of  copper  shaped 

c  la  Sorif'tr   Frun<;:i  l -<•  <!<•   l'liy-l<|Ui'.   April. 


THK    X-KAY  707 

hoof  and  has  a  platinum  surface.  The  regulator  is  a  tube  containing 
])o\vdered  asbestos  mixed  perhaps  with  a  little  potash.  Preparing  to 
take  a  radiograph  with  this  tube  the  regulator  spark  is  placed  at  a 
distance  of  ">  inches  and  a  current  of  11  amperes  with  a  Cald\vell  inter- 
rupter is  turned  on  until  sparks  cease  to  pass.  Then  a  change  is  made 
to  the  \\ehnelt  interrupter  with  a  current  of  1")  amperes  until  sparking 
ceases,  and  finally,  to  the  \\  ehnelt  interrupter  with  Is  amperes  of  prim- 
ary current.  The  whole  process  of  regulation  takes  half  a  minute  or  less 
and  the  picture  is  made  as  soon  as  this  adjustment  is  finished. 

It  must  not  be  imagined,  however,  that  this  or  any  other  type  of 
tube  may  lie  expected  always  to  be  in  a  condition  to  give  the  best  pos- 
sible results  as  above  described.  Such  a  tube  as  we  are  describing 
may  be  found  to  produce  these  results  when  it  is  first  purchased,  and 
if  it  is  used  only  for  radiograph}';  and  only  with  the  specified  strength 
of  current  and  length  of  exposure  it  may  remain  in  this  condition  for  a 
great  length  of  time.  Another  tube  of  the  same  type  may  prove  dis- 
appointing at  first  and  may  gradually  work  into  a  desirable  condition, 
while1  others  may  require  to  be  pumped  out,  exhausted  to  different 
degrees  of  vacuum  a  number  of  times  before  perfection  is  obtained. 
It  is  no  exaggeration  to  say  that  every  x-ray  tube  of  every  type  in  the 
author's  possession  has  been  pumped  out  several  times.  A  tube1  which  is 
absolutely  perfect  and  which  has  not  been  abused  will  eventually  cease 
to  work  properly  because  the  vacuum  regulator  becomes  exhausted. 
A  new  regulator  must  then  be  introduced  and  as  this  involves  opening 
the  tube  the  latter  must,  of  course,  be  reexhausted.  The  same  tube- 
maker  being  patronized  right  along,  he.  of  course,  knows  to  what  degree 
of  vacuum  the  exhaustion  should  be  carried  to  fit  the  tube  for  the  opera- 
tor's apparatus  and  methods. 

Tubes  with  the  same  type  of  anticathode  as  this  Machlett  hi.irh- 
t  reque.ncy  tube1  are  made  by  a  number  of  other  manufact  urers  in  America 
and  Europe,  and  generally  give  excellent  results  with  quite  heavy 
currents  and  short  exposures. 

The  Renifar  Self-rectifying  x-Ray  Tube. — By  surrounding  the  metal 
stem  of  the  anticathode  with  glass,  somewhat  in  the  way  European 
manufacturers  have  long  been  in  the  habit  of  doing,  an  effort  is  made  to 
suppress  inverse  discharge. 

A  test  was  made  by  the  author  with  the  Renifar  .r-ray  tube  in- 
tended to  be  self-rectifying.  In  addition  to  the  appearance  of  the  .r-ray 
tube  and  the  reading  of  the  milliamperemeter  which  showed  the  direc- 
tion and  strength  of  the  prevailing  current,  an  oscilloscope  in  series  was 
a  No  observed.  Xo  spark-gap  or  ventril  tube  was  used.  AVith  an 
ordinary  r-ray  coil,  with  the  correct  polarity  connected  with  this  tube, 
there  \va<  no  inverse  current.  But  connected  with  the  wrong  polarity 
the  current  pacing  from  the  positive  terminal  of  the  coil  to  the  negative 
terminal  of  the  .r-ray  tube  was  not  prevented  from  passing  through  the 
tube.  For  practical  purposes  the  tube  was  self-rectifying. 

A  similar  result  was  obtained  with  the  author's  direct  high-tension 
iienerator.  And  the  manufacturers  report  that  the  current  from  a  step- 
up  transformer  without  a  high-tension  rectifier  will  pass  through  this 
tube  in  one  direction  only.  It  is  hoped  that  this  or  other  self-rectifying 
.r-rav  tube-  may  afford  us  the  advantage  of  an  .r-ray  generator  without 
moving  parts. 

The  Hydrogen  x-Ray  Tube.     The   gas   in    the   tube   is   hydrogen. 


,t),S  MKDICAI.    ELECTRICITY    AM)    RONTGEN    HAYS 

There  is  a  sealed-, tt'f  accessory  bulb  surrounding  an  osmo-regulator  and 
containing  a  sufficient  quantity  of  hydrogen  for  a  great  many  regula- 
tions, lowering  the  vacuum.  Another  osmo-regulator  outside  the  hy- 
drogen bulb  with  a  cuff  of  platinum  raises  the  vacuum  by  withdrawing 
hydrogen.  Hither  regulator  is  heated  by  the  high-tension  current  when 
the  necessary  connections  are  made.  The  anticathode  is  a  block  of 
copper  with  a  tungsten  button. 


MAC  ALASTE  R  -WIGGIN   CO. 


Fi<:.  -ISO. — The  hydrogen  j-ray  tube.     (Macalastor- \Viggin  Co.) 

The  commendable  features  of  the  hydrogen  tube  are  not,  however, 
a  panacea  for  gas-filled  tube  difficulties.  These  are  the  inconvenience 
or  possible  difficulty  of  regulating  the  degree  of  vacuum  back  and  forth 
for  different  kinds  of  work  and  a  temporary  untitness  for  use  when 
overheated.  Both  of  these  drawbacks  are  present  to  a  very  much 
ureater  extent  in  any  gas-filled  tube  than  in  the  Coolidge  tube. 


The  NitroKen  x-Ray  Tube.  The  residual  nas  is  nitron-en  and  this 
i-  al-o  liberated  tn>m  the  material.-  in  the  regulator  when  the  vacuum 
i-  to  be  lowered. 

I'.xperiment  -  by  A.  Mutscheller1  -how  that  nitron'en  shows  the 
I'':'-'  tendency  to  combine  with  the  electrode  metals  most  commonly 

'Principle-    fr,r    the   ("-e   i  if    Rniituen-rMV    Tubes,     \     Mut-i-heller     .\e\v  York 
11)17,  p.   l_> 


THE    X-RAY 


709 


used;  and  it  is  selected  therefore  as  the  residual  gas  for  the  XitroKen 
tube.  This  shows  a  dense  yellowish-green  fluorescence.  Its  regu- 
lator contains  nitrites  of  thorium,  aluminum,  and  barium,  which 
when  heated  liberate  nitrogen;  and  they  tenaciously  hold  other  gases, 
such  as  oxygen  and  hydrogen.  In  regulating,  if  the  vacuum  becomes 
a  little  lower  than  normal  the  current  passes  through  the  vacuum  to  a 
wire  leading  to  the  anode  and  no  longer  through  the  regulating  substance. 
Allow  the  tube  to  cool  fifteen  minutes  and  then  pass  a  moderate  cur- 
rent, such  as  20  ma.,  for  one-tenth  second  Hashes  frequently  repeated 
through  it  to  raise  vacuum  to  normal;  or  3  to  0  ma.  for  longer  times. 

\'act(ittn  Regulator. — The  materials  in  common  use  (asbestos,  char- 
coal, caustic  alkalis,  soda,  lime,  asbestos-wool)  when  heated  by  a  high- 
tension  current  as  a  rule  yield  water  vapor,  carbon  dioxid,  or  hydrogen. 
All  these  tend  to  render  the  vacuum  unstable  as  compared  with  pure 
nitrogen.  There  is  danger  of  overregulation  and  occasional  require- 
ment of  a  new  regulator. 

The  NitroKen  tube  regulator  is  claimed  to  be  practically  inexhaust- 
ible, but  an  inconvenience  is  that  the  vacuum  always  becomes  too  high 
after  exposure  and  requires  reduction  when  used  again.  The  advantages 


Fig.  491. — The  Tousey  single-focus  radiographie  x-ray  tube. 

claimed  are  great  constancy  of  vacuum  during  prolonged  or  heavy  ex- 
posures and  that  no  seasoning  is  required. 

Texts  of  the  NitroKen  Tube  by  A.  Mutscheller, — Six-inch  spark 
04,000  volts,  5  ma.  for  eight  minutes;  target  red  hot,  but  vacuum  un- 
changed. 

Four-inch  back-up,  40  ma.  exposure  of  ten  seconds,  in  steps  of  one 
second  each;  twenty  seconds,  pause;  another  exposure  of  ten  seconds, 
produced  no  change  in  vacuum. 

Reduced  as  far  as  possible  and  also  passing  a  current  of  30  ma. 
through  the  regulator  for  ten  seconds;  then  showed  a  back-up  of  2^ 
inches  with  a  current  of  40  ma. 

After  standing  fifteen  minutes  and  receiving  occasionally  a  few  flashes 
of  20  ma.  it  was  4-inch  back-up  and  40  ma.,  and  fifteen  minutes  later  tin- 
vacuum  was  so  high  as  to  have1  required  reduction  for  use. 

A  few  tubes  have  been  particularly  described,  but  this  is  not  intended 
as  an  implication  that  others  not  alluded  to  are  inferior. 

Sinclair  Tousey's  Tube  for  Radiography. —  77?  r  Xin<ilc-focu$  TI/JH 
(Fig.  4!)n.~  The  author's  idea  is  thai  of  a  heavy  anticathode  situated 
in  a  small  bulb  an  inch  or  two  in  diameter,  made  of  soda  glass,  trans- 
parent to  the  .i'-ray,  and  giving  as  complete  a  hemisphere  of  direct 
41) 


MEDICAL    KLKCTKICITY    AM)    RONTGEN    KAYS 


radiation  as  any  large  tube,  but  a  much  smaller  surface  of  glass  to  emit 
secondary  rays.  This  small  bulb  has  a  number  of  prolongations  which 
arc  made  of  lead  glass  practically  opaque  to  .r-rays,  either  direct  or 
secondary.  Near  the  extremity  of  one  prolongation  is  })laced  the  cath- 
ode for  which  there  is  not  room  in  the  small  bulb  because  it  must  be 
placed  a  distance  from  the  anticathode,  bearing  a  certain  relation  to  the 
voltage  to  be  employed.  Another  prolongation  from  the  small  bull) 
transmits  the  stem  of  the  anticathode.  The  uninsulated  positive  and 
negative  terminals  of  the  tube  must  be  at  such  a  distance  from  each 
other  that  there  will  be  no  sparking  between  them  or  from  either  of 
them  to  the  opposite  electrode  inside  the  tube.  The  latter  occurrence 
would  cause  a  puncture.  By  another  prolongation  the  small  bulb 
communicates  with  a  large  bulb  of  lead  glass.  This  acts  as  a  reservoir 
of  rarefied  gas  and  prevents  the  rapid  change  in  vacuum  which  would 
occur  from  the  passage  of  a  heavy  current  through  a  small  tube.  The 
vacuum  regulator  and  the  accessory  anode  ar"  connected  with  this  large 
bulb. 


till'. — The  Tousry  bifocal   railio^rra 


The  small  bulb  of  soda  glass  permits  of  radiation  of  direct  rays  from 
the  focus  in  every  direction  in  front  of  the  plane  of  the  anticathode  or 
almost  a  hemisphere  of  illumination.  This  is  a  great  advantage  over 
a  large  tube  of  lead  glass  with  a  small  window  of  soda  glass,  which,  while 
it  may  afford  an  equally  small  area  for  the  radiation  of  secondary  rays, 
•lives  only  a  very  limited  angle  of  divergence  of  the  direct  rays,  and 
requires  either  that  only  a  small  picture  be  made  or  that  the  tube  be 
|  ilaci  'd  at  a  un  §at  <  list  ance. 

The  single  focus  type  is  preferable  in  every  case  in  which  a  unidirec- 
tional high-tension  discharge  can  be  obtained  as  with  an  induction-coil 
<>r  a  static  machine  or  a  direct  current  step-tip  rotary  transformer,  or 
an  allernai  my1  current  step-up  transformer  with  some  kind  of  a  rectifier. 

77"  Tnuniif  l>'ii, i, -til  l^in/i/i/inijifiir  1'nlx  ( Fi<r.  -1(,)2K  The  anticathode 
is  wedge  shaped  so  as  to  present  surfaces  of  coiiiact  for  cathode  rays 
iroin  two  different  directions,  and  these  rav-  are  focused  quite  near  the 
aii^le  ni  'lie  wedge,  so  that  the  two  points  from  which  the  direct  .r-ray 
radiate  are  as  close  together  as  practicable.  The  larger  bulb  and  the 
<  ii'i' ':'<Mii  prolongations  are  made  of  lead  glass.  There  are  two  regular 
cathodi  concave  disk.-  at  opposite  extremities  and  to  these  are  attached 
the  two  terminals  of  the  Tesla  coil,  or  the  step-up  transformer  or  other 
source  of  hinh-tensinn  alternating  current.  Neither  wire  is  attached 
to  the  anlicathode.  At  each  impulse  in  one  direction  the  concave 


THK    .T-KAY  771 

disk  electrode  ;it  one  end  is  the  cathode  and  concentrates  a  cathodi 
-tream  upon  the  nearest  surface  of  the  anticathode,  while  at  the  same 
time  the  opposite  concave  electrode  is  the  anode.  At  the  alternate! 
impulses  in  the  opposite  direction  the  other  electrode  becomes  the 
cathode.  Direct  rays  thus  arise  from  the  two  surfaces  of  the  anticathode 
alternately  and  together  they  illuminate  considerably  more  than  a 
hemisphere.  The  rays  from  the  two  separate  foci,  of  course,  produce 


Yip..  493.  —  A'-rays  from  the  two  foci    in  the  Tousey  bifocal  radiographic  tube  are  nearly 

parallel. 

separate  images,  but  if  the  foci  are  near  together  the  images  will  practi- 
cally coincide.  Fig.  493  rather  underestimates  the  approach  to  par- 
allelism between  the  direct  rays  from  the  two  foci  passing  through  any 
object  (a). 

The  nearer  the  object  is  to  the  plate  the  less  is  the  blurring  effect, 
and  if  the  object  is  half-way  from  the  plate  to  the  anticathode  its  two 
images  are  only  as  far  apart  as  the  two  foci. 

Whether  the  tube  shall  be  provided  with  accessory  anodes  to  be 
connected  with  the  two  concave  electrodes  is  a  detail  to  be  worked  out 
by  (Mich  constructor.  The  small  bulb  alone  radiates  secondary  rays, 
and  it  is  so  small  (only  an  inch  or 

two  in  diameter)  that  these  rays  , 

do  not  blur  the  image  produced 
by  the  direct  rays. 

The  object  of  the  Sinclair 
Tonxcy  x-ray  tubcx  for  radiog- 
raph// is  to  secure  the  improved 
definition  which  is  obtained  by 
the  use  of  a  diaphragm  with  the 
increased  range  of  illumination 
produced  by  the  author's  radiat- 
ing cellular  diaphragm,  but  with 
the  great  additional  convenience 
of  being  able  to  dispense  with 

diaphragms  altogether  except  when  simple  protective  ones  of  very  easy 
adjustment  are  required. 

The  Endodiascope. — .1  Tube  which  May  He  Placed  Inside  tin-  Month 
for  Radiography  and  Radiotherapy, — The  tube  (Fig.  494)  has  the 
anticathode  at  the  tip  of  a  prolongation.  The  anticathode  has  no 
electric  connection,  being  independent  of  the  anode,  which  is  at  a 
poll  ion  outside  the  mouth.  There  is  an  osmo-regulator.  The  tube  is 
suitable  for  use  with  a  12-  or  In-inch  induction-coil,  with  a  primary  cur- 
rent of  2  amperes  and  a  secondary  current  of  \  ni:l-<  'llld  will  run  for 
fifteen  minutes  continuously.  The  radiograph  (Fig.  40")).  poorly  re- 
produced from  a  magazine,  was  made  by  IJertollotti,1  with  this  tube 
the  mouth  and  the  plate  outside.  The  exposure  was  two 

acd.,  April  10,  1907. 


MEDICAL    ELECTRICITY    AND    HoNTCEN    KAYS 


I'*in(]  ihi*  T nix  for  Treatment. — The  same  strength  of  current  and 
with  a  degree  of  vacuum  producing  rays  No.  S  or  9  Benoist  and  with 
the  anticathode  at  a  distance  of  2  cm.  fifteen  minutes  exposure  equals 

3  Holzknechl  units.  The  tube  is 
useful  in  treating  cancer  of  the 
tongue  or  tonsils  or  simple  hy- 
pertrophy of  the  latter.  Ber- 
tolloti  has  cured  an  obstinate 
case  of  trigeminal  neuralgia  by 
application  to  the  inferior  dental 
nerve  with  this  tube  inside  the 
mouth.  Cancer  of  the  larynx 
has  been  treated  with  benefit  by 
holding  this  tube  far  back  at  the 
base  of  the  tongue,  the  rays  bc- 

ii:.  -tO.").— Radiograph  of  the  teeth  made     illg  directed   downward. 
.|iiil.uliascope  inside  the  mouth  and  the  The      GlaSS      of      Which      the 

x-Ray     Tube     is     Made. — The 
and  gives  an  apple-green  fluor- 
escence when  the  x-ray  tube  is  in  operation. 

The  Lindemann  x-Ray  Tube. — An  x-ray  tube  patented  in  1907  by 
Fred  A.  and  ('has.  L.  Lindemann  consisted  of  a  bulb  made1  of  glass  con- 
taining lithium  borate  which  does  not  fltioresce.  This  was  claimed  to 
generate  practically  no  secondary  rays  and  to  avoid  the  necessity  for  a 
diaphragm  in  radiography. 

Localizing  or  Safety  x-Ray  Tubes. — These  are  made1  in  part  of 
glass  which  contains  a  large1  percentage1  of  le-ad,  and  which,  while1  per- 
fectly transparent  and  colorless  with  ordinary  light,  becomes  a  beautiful 
deep  blue  when  the  x-ray  tube  is  in  operation.  This  glass  is  very 
opaque  to  the  x-ray,  and  all  parts  of  the1  operator  and  the1  patient,  are 
shielded  except  opposite  a  window  of  soda  glass,  which  forms  part  of  the 
tube  and  permits  the  passage  of  x-rays  in  one  direction.  Many  different 
forms  of  tubes  like  this  have1  been  made  for  therapeutic  uses. 


glass   is  usually  German  soda  gla> 


A'-ray  Tubes  Without  an  Anticathode.  —  Kontgen's  original  .r-ray 
tube-;  were  made  without  an  unt  icat  hode.  'I  lie  x-rays  arose  from  the 
impact  nf  the  cathode  rays  upon  the  glass  wall  of  the  tube.  'There  were 
two  objections  to  thi-  for  radiography:  the  x-ray  radiated  from  many 
different  points  of  ;i  larire  surface  and  hence  the  shadows  were  very 
vairue  as  compart-d  with  those  produced  by  rays  radiating  from  a 
sinirle  point  :  and  the  irlass  wall  of  the  tube  became  overheated  if  a  heavy 
current  \viis  M-'<!.  The  -atne  objections  do  not  hold  as  to  a  tube  that 


THE    .C-KAY 


773 


is  used  for  treatment  if  the  tube  can  be  applied  directly  or  close  to  the 
tissues  and  if  the  current  is  a  weak  one.  Tubes  without  an  ant  icat  liode 
are  usually  made  of  lead  glass  except  for  a  prolongation  which  is  to  be 
inserted  into  some  cavity  of  the  body.  When  in  operation  the  main 
portion  of  such  a  tube  (Fig.  49('»  lights  up  with  a  blue  fluorescence  and 
the  prolongation  shows  the  apple-screen  fluorescence  characteristic  of 
soda  glass  under  the  influence  of  the  cathode  ray.  The  cathode  has 
the  usual  form  of  a  concave  aluminum  mirror  and  directs  the  cathode 
rays  into  the  prolongation,  where1  by  impact  with  the  glass  they  give 
rise  to  .r-rays  which  radiate  from  every  part  of  the 
surface  of  the  prolongation.  The  .r-ray  is  distinctly 
perceptible  if  the  iluoroscope  is  held  close  to  the  tube. 

Unipolar  .r-Ray  Tubes.  —  Tesla.  as  long  ago  as 
IMMi.  devised  an  .r-ray  tube  with  only  one  electrode 
which  was  connected  with  one  pole  of  a  Tola  coil. 
The  lube  had  a  vacuum  of  one-millionth  of  an  atmo- 
sphere and  when  applied  to  the  surface  of  the  body  or 
to  any  other  conductor  acted  in  the  same  way  as  one 
of  the  modern  ultraviolet  vacuum  electrodes.  The 
back-and-forth  surgings  of  the  high-tension  current 
caused  cathode  rays,  when  the  current  was  in  one 
direction,  to  impinge  upon  the  glass  and  j-rays  arose 
there.  The  unipolar  .r-ray  tube  devised  by  .Stern  of 
New  York  in  190o  (Fig.  497)  has  the  additional  feature 
of  a  concave  aluminum  mirror  as  the  electrode,  and 
(hiring  the  periods  when  the  current  is  in  the  right 
direction  this  is  a.  cathode  and  focuses  the  cathode 
stream  upon  the  ant  icathode  which  is  near  the  part 
applied  to  the  patient.  There  may  also  be  a  pro- 
longation for  .r-ray  treatment  inside  the  nose  or  any 
Other  cavity. 

The   ordinary  bipolar  x-ray  tube  may  act   as  a 
unipolar  .r-ray  tube  if  the  cathode  alone  is  connected 
with  the  single  terminal  of  a  high-frequency  apparatus 
capable  of  giving  a  4-inch  effluve.     The  tube  is  not  to  be  in  contact  with 
the  patient.     Its  radiance  is  sufficient  for  fiuoroscopic  work. 

A-ray  Tubes  Without  Any  Internal  Electrodes.  —  Pupin  exhausted 
glass  tubes  to  the  x-ray  degree  of  vacuum  and  connected  the  poles  of  the 
induction-coil  to  two  pieces  of  tin-foil  pasted  on  the  outer  surface  of  the 
bulb.  A  very  good  production  of  .r-rays  took  place. 

Guilloz's  x-Ray  Tubes  (Fig.  498).  —  These  tubes  are  large  bianodic 
tubes  which  allow  the  use  of  very  strong  intensities  and  work  satis- 
factorily on  coils  fed  through  a  YVehnelt  interrupter. 

The  anticathode  is  made  of  chromium,  which  is  just  as  infusible  as 
platinum  and  which  is  not  volatile,  so  that  it  does  not  blacken  the  tubes 
even  with  the  highest  intensities.  Chromium  enables  one  to  get  the 
same  quality  of  rays  as  platinum,  but  necessitate.-  a  more  precise  regula- 
tion of  the  equivalent  resistance  of  the  tube.  In  other  words,  the  same 
variation  in  the  equivalent  resistance'  gives  a  greater  variation  in  the 
hardness  of  the  rays  in  the  case  of  a  chromium  anticathode  than  in  the 
case  ot  a  platinum  one.  Chromium  may  be  platinized  by  electrolysis  as 
well  as  iron,  and  thus  are  obtained  voluminous  anticathodes  as  lasting  as 
platinum  anticathodes  of  the  same  si/.e.  and  having  exactly  the  same 
properties  for  the  emission  of  .r-rays. 


Fi,r  107.  —unipolar 
x-my  tube. 


<(1  MKlMi  AL    KLKCTKH  TfY    AND    RONTGEN    HAYS 

C'hroiniuni  being  hard  and  brittle  and  difficult  to  work,  Dr.  (Juilloz 
has  overcome  t hr  ditlicult y  by  pulverizing  it  and  agglomerating  tlu1 
powder  by  strong  hydraulic  pressure.  A  small  quantity  of  spongy 
platinum  placed  on  the  chi-oiniuiu  before  the  application  of  the  heavy 
pressure  enables  u>  to  obtain  tablets  of  platinixed  chroiniuin  which  are 
hard  and  resistant  enough  to  take  the  place  of  cast  metal.  The  same 
method  ol  agglutiiiixation  of  metallic  powders  enables  us  to  get  anti- 
rathodic  mirrors  formed  by  conglomerates,  the  surface  and  the  body  of 
which  are  respectively  constituted  by  substances  we  know  to  be  desirable 
as  anticathodie  surfaces  or  as  supports  for  ant  icat  hodic  mirrors. 

(iuillo/  has  found  that  metallic  hydrids.  such  as  barium  or  cal- 
cium hydrid.  have  no  appreciable  ten-ion  of  dissociation  in  the 
cathodic  vacuum,  and  that  an  electric  spark  or  ellluve  sent  between 
two  little  electrodes  made  of  these  hydrids  liberate-  hydrogen.  These 
properties  allow  us  to  regenerate  the  gas  necessary  for  the  good  working 
of  a  tube  which  has  become  too  hard.  T<.  that  effect,  part  of  the 
current  is  diverted  to  two  small  accessory  electrode:-  contained  in  the 
tube  and  carrying  (either  one  or  both.<  calcium  hydrid  on  one  of  their 
extremities.  These  electrodes  are  prepared  by  keeping  calcium  hydrid 


Fit:.  49.s.— Tu 


cylinders  in  hydrogen  gas  at  oDO"  ('..  but  not  long  enough  to  have 
1  he  met  a  I  attacked  to  t  he  center;  if  the  time  of  exposure  were  too  long 
t  he  elect  rode  would  be  friable. 

This  regenerator  is  belter  than  that  formerly  used  by  Guilloz,  which 
was  formed  bv  thin  sheets  between  which  a  spark  was  sent.  The  cal- 
cium hydrid  electrodes  have  an  unlimited  regenerative  power. 

Th'-  tube-  harden  m  the  course  of  their  natural  use.  They  may 
b'-come  too  ~otl  n  too  si rong  a  current  ha>  been  used  or  t oo  manv  sparks 
are  -•  '  •  nto  the  regenei'ator.  In  the  latter  case  a  good  vacuum  may 
be  re-tored  !iv  -ending  a  \\"eak  current  t  h  rough  t  he  t  ube  for  a  long  time. 

I  oi  a   toot  h  piclure  or  one  of  a  hand  any  t  ube  will  be  suitable  which 

'.'."ill    give    a    good    brilliant    fluorescence    in    the    fluoroscope    and    whose 

,:M    can    be   adjusted    for   the   work    in     hand,    but     for    the    thicker 

port  i  ,  e    body   one   of   the   heavy    target    tube.-    i.-   alwavs   to   be 

.   lor  the  most    difficult   work   the  operator,  of  cour.-e,  will 

u.-e   rhf   type  o]    tube   which    he   lia-   foiij.d    will   .-land   a    heavy   current 


,'."!'  I  I0l|'      .'      ••'..'',      c|i;jl)<rf  •     (i(      \'aC,.  ,,,... 

The  Coolidge  .r-Ray  Tube.1— This  i.-  a  tube  in  which  there  is  practi- 
cal!\"  a   perti-ci    vacuum.      The  cathode  and  anticathode  are  very  close  to 
-  \\  i;,    IV  (  '.).,li,|jri-.   I'hy.-ica!   K.-VICNV,   [).-f.,   I'.M.1,. 


TIIK    .T-KAY  775 

each  other,  and  the  cathode,  only  ',  inch  in  diameter,  is  formed  of  a  flat 
spiral  of  tungsten  win1,  which,  when  heated  by  t  he  current  from  a  storage- 
battery,  liberates  electrons,  and  these  carry  the  current  across.  The 
short  space  forms  an  absolute  barrier  to  the  passage  of  even  the  highest 
tension  current  while  the  anticathode  is  cold,  but  when  the  electrons  are 
liberated  by  heating  the  cathode  a  potential  of  even  220  volts  will  -end  a 
current  through  the  tube,  and.  according  to  our  accepted  theory,  should 
generate  extremely  soft  .r-rays.  The  hotter  the  cathode  is  made  by 
adjusting  the  rheostat,  so  as  to  send  more  storage-battery  current  through 
it,  the  more  ions  are  liberated  and  the  more  current  is  transmitted  under 
the  influence  of  a  given  potential.  The  quantity  of  .r-rays  produced  in- 
creases in  extent  corresponding  with  the  milliamperage,  but  the  quality 
remains  the  same  unless  the  voltage  also  changes.  Instead  of  220  volts 
electric-light  current  a  high-tension  current  from  one  of  the  regular 
types  of  .r-ray  generators  will  commonly  be  employed  and  the  .r-rays 
are  correspondingly  harder.  I  purposely  use  the  words  "soft"  and  "hard'' 
in  this  description.  Soft  rays  are  those  of  which  a  large  percentage  are 
absorbed  by  a  thin  layer  of  tissue,  while  only  a  small  fraction  of  hard 
rays  are  absorbed  by  the  same  obstacle.  The  tube  may  be  manufac- 
tured so  as  to  have1  either  a  large  or  a  small  focus  spot. 

This  tube  represents  a  very  important  improvement  in  producing 
re-rays  of  approximately  uniform  spectrum,  which  can  be  regulated  for 
various  treatment  and  examination  purposes,  and  of  an  intensity  which 
may  also  be  regulated  within  wide  limits. 

It  presents  some  striking  differences  from  previous  x-ray  tubes: 
The  cathode  is  hot  and  luminous. 

When  actuated  by  a  current  of  25  ma.  from  an  .r-ray  generator  the 
anticathode  soon  acquires  a  cherry-red  heat,  with  50  ma.  a  white  heat, 
and  with  150  ma.  it  looks  as  if  the  anticathode  might  melt  off  and  the 
tube  be  destroyed. 

The  tube  does  not  exhibit  the  illuminated  hemisphere  characteristic 
of  other  .r-ray  tubes.  This  may  indicate  the  absence  of  the  secondary 
.r-radiation  from  the  glass  wall  of  the  tube,  which  I  regard  as  the  chief 
source  of  the  secondary  .r-rays  which  have  a  blurring  effect  in  radiog- 
raphy and  ordinarily  require  the  use  of  a  diaphragm.  This  may  prove 
of  great  advantage  in  not  requiring  a  diaphragm. 

The  ('oolidge  tube  is  self-rectifying  to  a  very  great  extent,  and  the 
radiator  type  ('oolidge  tube  is  especially  designed  to  allow  the  passage 
of  current  in  only  one  direction.  This  enables  one  to  use  the  tube  with 
a  step-up  t  transformer  without  any  rectifier  and  without  any  valve  tubes. 
)r.  ( 'ooiidge  explains  the  fact  that  the  radiator  type  of  ('oolidge 
to  a  irreat  extent  self-rectifying,  on  the  ground  that  the  anti- 
does  not  usually  become  incandescent  nor  liberate  electrons, 
:>1  ordinarily  act  as  a  cathode. 

•uriotis,   however,   that   the  author  has  noted  an  increased  re- 
-hown    by   a    higher   voltage   as   such    a    tube   has   become   hot 
enough  i<>r  the  anticathode  to  be  incandescent. 

The  resistance  of  the  1  ube  is  liable  to  drop  -uddenly  under  very  heavy 
current,  but  will  return  to  the  normal  as  soon  a-  the  current  is  turned  off. 

Experiment  s   by  ( 'ole'   show   that    with   a   current    of  :•>()  ma.   and   a 
resistance  equal   to   that    of  a    parallel   irap  of  5   inches,   an   expo<ure  of 
tit  teen  seconds  is  excellent  for  frontal  sinus  radiography;  5-inch  parallel 
American  .Journal  of  Rontircnnlo'iY,  .Januarv,  1914,  p.  llM. 


<<»)  MEDICAL    ELECTRICITY    AND    RONTe.EN    RAYS 

gap.   100  ma.,  and  .(Hi  second  for  a  screen  picture1  of  the  stomach;  1% 
to  2  inch  parallel  uap.  2">  ma.,  and  two  seconds  for  the  hand. 

An  experiment  by  ( 'ole  shows  that  with  a  parallel  gap,  7:,  inch,  10 
to  S  ma.,  a  total  exposure  of  six  minutes,  with  a  screen  of  o  mm.  of  alum- 
inum, there  was  at  .">',  inches  from  the  anticathode  a  surface1  effect  of 
S  II..  and  at  the  further  side  of  a  piece  of  beefsteak,  2  inches  thick,  an 
effect  of  4  II. 

The  vacuum  is  practically  absolute.  The  tube  is  Invited  as  hot  as 
possible  without  softening  the  glass  while  completely  enclosed  in  an 
oven  for  an  hour  or  two.  This  liberates  most  of  the  air  and  other 
gases  or  vaporizable  substances  in  the  component  parts  of  the  tube. 
Then  with  the  air-pump  -till  in  operation  and  with  the  filament  current 
and  also  the  high-tension  current  turned  on  the  anticathode  is  kept 
brilliantly  incandescent  for  about  an  hour. 

The  cathode  is  essentially  a  small  coil  of  tungsten  wire1  which  when 
traversed  by  a  cunvnt  of  about  12  volts  ;.nd  something  like1  4  am- 
peres becomes  incandescent  anel  liberates  electrons.  These  are  carried 
by  a  high-tension  e-urre-nt  as  the'  cathode1  stream,  whose  impact  upon  the 
antie-athode  produce's  .r-rays.  The-  high-tension  current  cannot  pass 
through  the  Coolidge  tube1  unless  the1  cathode-  filament  is  in  a  state  of 
incandescence.  If  the1  filament  is  broken,  or  the  low-tension  current  is 
not  turned  on.  or  the  low-tension  cire-uit  is  broken  by  a  bad  connection 
somewhere,  then  no  voltage,  however  high,  will  cause'  electricity  to 
traverse  the  space  of  an  inch  or  less  between  the-  cathode1  and  the  anti- 
cathode. 

A  im-ater  degree-  of  incandescence-,  caused  by  gre-ater  amperage 
of  the  filament  current,  lowers  the  resistance  to  passage1  of  the  high- 
tension  current  anel  produce1-  all  the-  effects  of  lowering  the-  vacuum  in 
a  u'as-filled  tube:  vi/..  shorter  parallel  spark-gap,  lesser  voltage-,  greater 
milliamperaue.  lesser  de-give  of  penetration  as  measured  by  Be'iietist 
-rale,  greater  contrast  of  light  anel  shadow  in  a  radiograph  or  upon  the 
fluorescent  screen.  This  can  be-  instantly  varied  e-ven  during  an  ex- 
pi  t-ure  of  a  few  seconds. 

The  ii/i/iciif/Kx/t  in  the  standard  Coolidge-  tube  i-  a  solid  mass  of 
tungsten  which  actively  generates  .r-rays  of  a  useful  spectrum  and  which 
i-  very  resistant  to  heat,  with  a  melting-point  of  MMOO  F.  The  Radiator 
Type  (  'nolidu'e-  tube's  have  an  anticathode  consisting  of  a  block  e»f  ce>p- 
per  with  a  tunu'sten  button  at  the  focus.  The  anticathode  stem  is 
-"lid  and  project-  outside  the-  tube1.  To  this  stem  is  attae-he-el  a  radiator 
fur  the  rapid  di--ipation  of  heat  in  the  air. 

( >/,<  ration-  A  current  of  12  volts  and  about  1  amperes  is  sent  through 
the  filament  from  a  -torau'e-bat tery  or  a  transformer,  anel  cither  of  these 
mu-t  ordinarily  be  in-ulated  so  that  one  wire  may  be  connected  with 
hiuh-tcn-ion  circuit  without  danger  of  grounding.  High-tension 


ale    snows    ad  ive    .r-ra< lia t  ion. 
in   l  he  standard   1  ul  >e  even   1  •  ! 

-pecial  connection  with  the  production  of  .r-rays. 

iated  hemisphere  -mme-is  ab-ence  of  secondary 
the  <ila-s  wall  and  experiment-  prove  this  to  be  the 
"  less  nece--ary  to  u-e  a  -mall  diaphrainn  for  radi- 


THE  ar-itAY  777 

ography  than  with  the  gas-filled  tube,  except  for  reducing  the  amount 
of  secondary  rays  originating  in  the  tissues  of  the  body  by  limiting  the 
area  of  the  body  exposed  to  the  .r-ray  at  all. 

The  absence  of  fluorescence  in  the  glass  wall  of  the  Coolidge  tube 
has  been  studied  in  the  research  laboratory  of  the  General  Electric 
Company,  the  manufacturers.  It  is  considered  due  to  the  inability  of 
secondary  cathode  particles  arising  from  the  focus  point,  on  the  anti- 
cathode  to  traverse  3}  inches  of  perfect  vacuum  and  reach  the  glass 
wall  of  the  tube. 

When  a  Coolidge  tube  is  used  in  the  experiment  with  a  silver  half- 
dollar  midway  between  the  anticathode  and  the  fluoroscope,  and  a 
ten-cent  piece  close  to  the  screen,  the  ten-cent  piece  is  eclipsed  in  t he- 
shadow  of  the  half-dollar  instead  of  being  strikingly  visible  therein,  as 
with  the  gas-filled  tube. 

The  .r-radiation  from  every  part  of  the  tungsten  target  of  the  Coolidge 
tube  as  shown  by  pin-hole  radiographs  the  research  workers  of  the 
General  Electric  Company  consider  due  to  secondary  cathode  particles 
originating  at  the  focus  point  and  unable  to  traverse  8-j  inches  of  perfect 
vacuum  to  reach  the  glass  wall  of  the  tube,  being  in  a  sense;  reflected 
back  upon  other  parts  of  the  target.  There  these  secondary  cathode 
particles  are  thought  to  give  rise  to  secondary  .r-rays.  Pin-hole  radio- 
graphs are  made  by  having  a  small  hole  in  a  large  sheet  of  heavy  lead 
placed  midway  between  the  anticathode  and  the  plate.  They  show  in 
the  standard  tube  active  .r-radiation  from  the  entire  surface1  of  the 
tungsten  front,  back  and  sides,  not  merely  from  the  focus  spot  on  the 
face  of  the  anticathode.  With  such  a  large  source  of  radiation  there; 
is  a  loss  of  definition,  which  is  the  reasem  why  the1  Standarel  Coolidge 
tube  was  regarded  as  insuiteel  for  locating  foreign  bodies.  This  can  be1 
overcome  by  the  use1  of  a  very  small  diaphragm  which,  of  course,  reduces 
the  size1  of  the  picture  to  an  impracticable  extent.  The1  author  suggested 
to  the  General  Electric  Company  the  use*  of  a  copper  target  with  a 
tungsten  button  to  overcome  this  objection. 

In  the1  Radiator  Type  of  Coolidge  tube-  a  tungsten  button  is  em- 
be'dded  in  a  mass  of  copper  which  produce's  so  little1  disturbing  .r-rad- 
iation that  the1  definition  is  very  much  improved. 

Th  Author'*  Suggestion  for  Coolidge  Tube*. — This  consists  essentially 
in  placing  the  anticathode  body  of  the1  standard  tube  at  about  a  right 
angle  to  the'  long  axis  of  the  tube  so  that  its  end  is  directed  toward  the 
plate.  This  rcdue-es  to  a  minimum  the  disturbing  radiation  while-  per- 
mitting the  use  of  a  solid  tungsten  target  with  its  great  heat  resistance. 

The-  Ge-neral  Electric  Company  had  experimentally  made  Coolidge 
tubes  with  the  anticathode  elire-cted  in  this  way,  but  I  believe  its  ad- 
vantage- had  not  be-en  recognized. 

Regulation  of  I  he  Coolitlt/c  Tube. — The  object  to  be-  accomplished  is 
to  adjust  its  resistance  so  that,  with  the  proper  gvnerator  power,  there 
will  be  a  certain  voltage1  or  resistance  or  parallel  spark  and  a  certain 
number  of  milliamperes  of  high-tension  cunvnt.  as  determineel  In- 
experience to  be  suited  for  the-  radiographic  or  therapeutic  expeisure 
which  is  to  be  made1.  The  resistance  of  the  Coolidge  tube  is  reu'ulate-d 
by  varying  the  rheostat  resistance  in  the  filament  circuit.  The  hiu'h- 
tension  current  is  regulated  usuallv  by  varying  the-  rheostat  resistance 
of  the  generator,  but  sometime-  also  by  varying  the  ratio  of  trans- 
formation, which  must  be  done  first  of  all  if  required.  For  instance, 


<<h  MKDICAL    KLK<  TRH  ITY    AM)    KO.NTCKN     KAY.-> 

with  the  author's  generator  as  originally  constructed,  there  was  one 
adjustment  with  which  even  the  full  power  and  the  highest  resistance 
would  not  exceed  til)  kv..  hut  this  would  tiive  an  enormous  milliam- 
peratie  at  that  voltatie.  And  another  adjustment  made  variations  up  to 
above-  100  kv.  an  easy  matter.  The  1  .  S.  Army  portable  outfit1  lias  a 
fixed  ratio  of  tiansformation  of  the  high-tension  current  and  a  fixed  re- 
sistance in  the  filament  current,  so  that  the  only  variable  factor  is  the 
re-istaiice  in  the  primary  of  the  high-tension  generator.  And  for  this 
apparatus  all  the  opera. tor  has  to  do  for  radiography  is  to  adjust  the 
last-named  resistance  so  that  \\  or  .">  ma.  will  pass  through  the  Coolidge 
tube,  knowing  that  this  \\-\\\  automatically  produce  a  parallel  spark  of 
.">  inches.  Ordinarily,  however,  the  filament  current  is  regulable.  It 
is  of  the  greatest  assistance  to  have  a  table  of  adjustments  for  one's 
own  apparatus.  This  can  be  supplied  in  part  by  the  manufacturer, 
but  parts  must  be  worked  out  by  the  operator  himself. 

The  adjustment  of  the  primary  rheostat  of  the  generator  and  of  it- 
ratio  of  transformation  control  the  amount  of  power  applied  to  the 
.r-ray  tube  and  the  limits  of  its  voltage.  The  factorial  division  of  this 
power  into  quantity  or  milliamperage,  and  ten-ion  or  voltage  or 
parallel  spark-gap  is  regulated  by  the  rheostat  of  the  filament  current. 
Thus,  placing  the  handle  of  this  rheostat  in  a  certain  position  auto- 
matically sends  a  certain  number  of  amperes  through  the  cathode 
filament,  causing  the  tube  to  have  a  resistance  equal  to  that  of  a  certain 
parallel  spark-gap  and  to  be  capable  of  transmitting  a  certain  number 
of  millianiperes. 

The  table  should  state  that  with  each  adjustment  of  the  rheostat 
of  the  primary  of  the  high-tension  tienerator  (within  useful  limits") 
and  each  number  'from  r>.S  to  4.:i  by  halves  of  ,',,  •  of  amperes  of  filament 
current,  the  voltage,  parallel  spark,  and  milliamperage  will  be  so  and  so. 

To  determine  these  factors  for  oneself  1ak<s  time  and  patience,  but 
the  author  considers  them  essential. 

Begin,  for  instance,  with  the  determination  of  the  factors  for  a 
deep  therapeutic  exposure  of  '.]  ma.  and  70  kv.  If  the  handle  of  the 
generator  rheostat  moves  around  a  c'.r'-le  with  the  greatest  power  pro- 
duced by  a  1  o'clock  'as  on  a  clock  dial'  and  the  least  by  an  11  o'clock 
position,  probably  a  7  o'clock  position  will  be  about  right.  Set  the 
rheostat  handle  there.  Then  turn  on  the  filament  current  and  regulate 
it  to  :-'..s  ampere-.  Then  turn  on  the  high-tension  current  for  an  in- 
stant. If  the  voltatie  and  milliamperage  are  both  too  high,  reduce  the 
power  by  movinti  the  generator  rheostat  to  S  o'clock,  or  if  they  are 
>w,  move  the  rheostat  to  li  o'clock,  \\hen  we  reach  a  power 
•re  either  the  voltage  is  too  h'mh  and  the  millianiperage  too 
•  voltatie  too  low  and  the  milliamperage  too  great,  we  begin 
inilate  the  amperatie  of  the  filament  current,  and  this,  with  or 
nit  a  -li^ht  further  chantie  of  the  generator  rheostat,  will  enable  us 
cure  exactly  the  hi^h-t elision  current  factors  desired,  \\ith  the 
iwn  tieneralor  and  a  standard  ( 'oolidge  t  ube,  7  o'clock  generator 
>  amperes  filament  current  produce  exact Iv  70. 000  volts 


tho  power  by  moving  the  generator  rheostat  one  hour  mark,  and  find 
out  by  experiment  what  amperage  of  filament  current  corresponds  to 
70,000  volts  and  the  numher  of  milliamperes  which  tlien  flow  through 
the  Coolidge  tube.  Then  gradually  increase  the  filament  current, 
noting  for  its  different  values  the  voltage  and  milliamperage  produced. 
Do  the  same  tiling  at  different  hour  marks  up  to  the  highest  power  that 
the  manufacturer  advises  you  to  use.  At  the  higher  powers  it  will 
not  be  wi-e  to  reduce  the  voltage  below  GO, 000  because  of  the  enormous 
milliamperage  sent  through  the  standard  Coolidge  tube  and  its  conse- 
quent overheating;.  The  Radiator  ('oolidge  Tube  will  not  stand  more 
than  10  or  HO  ma.,  according  to  whether  the  focus  spot  is  small  or  large. 
Also  an  excessive  current  might  overheat  the  generator. 

The  table  should  especially  show  the  position  of  the  generator, 
rheostat,  and  the  filament  amperage  suited  for  deep  and  superficial 
radiotherapy:  for  fluoroscopy;  for  radiography  of  the  teeth  (with  oo 
kv.  and  80  maJ;  for  radiography  of  the. limbs,  chest,  and  kidneys 
(with  55  kv.  and  30  ma.")  and  30  ma.  with  (if)  kv.  for  gastro-intestinal 
radiography;  and  for  frontal  sinus  radiography  (with  (if)  kv.  and 
30  ma.). 

It  is  not  sufficient  to  set  the  rheostat  which  controls  the  filament 
current  at  what  is  considered  the  proper  position,  but  one  should  actually 
see  by  the  meter  that  the  proper  amperage  is  flowing  before  turning  on 
the  high-tension  current.  From  that  time  the  amperage  of  the  fila- 
ment current  is  disregarded  and  one's  attention  is  fixed  either  upon  the 
voltage  or  the  milliamperage  of  the  high-tension  current,  whichever 
meter  is  most  conveniently  placed  for  observation.  Meanwhile  one's 
hand  is  upon  the  rheostat  of  the  filament  current  ready  to  adjust  that 
to  counteract  changes  in  the  high-tension  current  so  as  to  maintain  the 
latter  practically  constant.  This  regulation  during  the  exposure  is 
necessitated  by  the  fact  of  changes  in  the  resistance  of  the  ('oolidge 
tube  which  would  prevent  uniformity  of  results  if  not  counteracted. 

Some  tubes  will  undergo  such  a  rapid  lowering  of  resistance  im- 
mediately upon  turning  on  a  very  strong  high-tension  current  as  to  re- 
quire very  great  regulation  instantly.  If  this  were  not  done  the  picture 
would  lie  ruined  and  the  tube  and  generator  might  be  damaged  by 
overheating.  Such  a  Coolidge  tube  had  better  be  used  only  for  the 
lesser  powers  where  its  variations  are  les-  rapid  and  there  is  more  time 
to  compensate  for  them  by  regulation  of  the  filament  current.  Or  the 
target  may  be  incandescent  to  start  with. 

S/)tirl;-i/ti/>  and  xphitrcniffcr  with  the  ('oolidge  tube.  It  is  quite 
a  useless  performance  to  adjust  the  generator  so  a-  to  produce  a  certain 
parallel  spark  with  the  tube  disconnected  or  its  filament  current  turned 
off.  But  the  value  of  the  spintremeter  is  very  great  for  standardizing 
one'-  voltmeter  with  the  tube  in  actual  operation.  The  voltmeter  on 
an  .r-ray  generator  is  generally  graduated  by  the  manufacturer  by  a 
system  ot  calculation  and  the  graduation-  may  be  quite  far  from  riuht. 
A  spark  between  two  insulated  polished  metal  spheres  a  certain  size 
and  with  a  certain  atmospheric  pres-ure  furnishes  a  very  exact  mea-ure 
of  voltage. 

And  even  the  ordinary  spintremeter  i-  very  useful  to  mark  on  one's 
voltmeter  graduations  corresponding  to  various  lentil hs  of  spark-ii'ap. 
But  the  Cooliduv  tube  can  be  adjusted  more  quickly  and  maintained 
more  easily  at  a  certain  spark  resistance  by  observing  the  voltmeter 


7SO  MKDH'AL    KLKCTHK'ITY    AM)    RONTOKN     HAYS 

than  by  fussing  with  the  spark-gap  itself.  And  one  can  leave  the  gap 
so  far  open  that  slight  variations  in  resistance'  will  not  cause  the  current 
to  Hash  across  the  gap  before  they  can  be  corrected  by  regulation. 

A  Coolidge  tube  -hould  always  have  its  filament  current  turned 
on  before  the  high-tension  current.  Some  tubes  will  show  a  very  marked 
drop  in  resistance  the  moment  that  a  powerful  high-tension  current  is 
turned  on,  as  described  elsewhere'.  This  is  a  disadvantage  which  has 
been  attributed  to  misuse  of  the  tube,  such  as  overheating.  It  certainly 
never  u'ets  better,  and  the  author  would  advise  testing  a  Coolidge  tube 
with  the  strength  of  current  that  is  to  be  used  for  one's  heaviest  regular 
work  before  making  a  purchase.  For  instance,  an  exposure1  suitable 
for  a  trastro-intestinal  radiograph  and  started  with  the'  right  factors 
-hould  not  result  in  a  terrible  drop  in  resistance1  and  voltage  and  a  ruin- 
ous increase  in  milliamperage.  The'  change  does  not  appear  to  be1  due 
entirely  to  a  reduction  in  the1  electric  resistance  of  the  filament.  And 
it  occur-  so  suddenly  on  turning  on  the1  high-tension  current  that  it  does 
not  seem  likely  that  it  is  due  entirely  to  liberation  of  electrons  by  in- 
candescence  of  the  anticathode.  Most  Coolidge'  tubes  require  slight 
regulation  during  an  exposure,  but  the  change  should  not  be'  so  great 
as  that  described  above1. 

The  disadvantage  referred  to  is  more  apt  to  manifest  itself  in  heavy 
radiographic  work  than  in  radiotherapy.  The  same  tube  may  transmit 
a  unifoim  current  of  o  ma.  and  70  kv.  for  ten  minutes  with  only  the1 
slightest  occasional  regulation  of  the  filament  current,  and  that  probably 
only  at  the  commencement  of  the  exposure. 

\\ith  the  standard  type  of  Coolidge'  tube  the'  marked  change  in 
resistance  as  the  anticathode  becomes  incanelescent  can  be'  rendered  less 
disadvantageous  by  starting  the1  exposure  with  the  tube  already  hot. 
The  resistance  remains  quite  uniform  during  even  a  prolonged  period 
of  anticathode  incandescence  provided  that  the  current  is  not  unduly 
strong. 

Making  all  adjustments  to  produce  a  f>-inch  spark  equivalent  and 
Mil  ma.  the  author  sometimes  introduces  all  the  primary  rheostat 
re-i-tance  and  so  reduces  the  power  to  a  minimum.  Doing  this  without 
touching  the  filament  rheostat  changes  the  spark  equivalent  to  a 
fraction  of  an  inch  and  the  milliamperage  to  about  If).  The1  .r-ray 
ha-  so  ii'tle  penetration  that  it  would  not  produce  a  noticeable1  effect 
upon  the  plate  through  a  patient's  body.  And  upon  a  film  covered  with 
thin  aluminum  five  seconds'  exposure  produces  the  same  effect  as  one- 
eiuhth  second  exposure  with  .Vinch  spark  and  MO  milliamperes. 

The  I'lunn  nl  cum  at  may  be  furnished  by  a  storage-battery  such  as 
two  of  the  units  having  three  cells  each  u-ed  in  gasoline  automobiles, 
for  i'j'nii  ii>M  and  liuhthm.  They  yield  12  volts  and  are  provided  with 
a  rheo-tat  bv  which  the  current  -cut  through  the  filament  may  be 
lated  from  about  M1,  to  -I1,  ampere-.  A  convenient  arrangement 
ruinii  con-ists  in  allowing  the  1  10-volt  electric  current  to  pass 
i  two  liO-walt  Ma/da  lamps  parallel  with  each  other,  but  both 
-  with  the  -toraiie-battery.  This  charging  current  of  about  1 
iid  lie  allowed  to  flow  thnnmh  the  -toraue-bat  tery  in  the 
t'i, ,n  after  each  utilization  for  six  or  eight  times  as  long  as 
current  ha- been  turned  on.  The  simplest  way  is  to  turn  on 
rent  in  the  interval-  of  a  -eric-  of  exposures  so  as  not 

end.  The  batterv  must  be 


THE    a'-HAV  781 

on  a  stand  with  insulating  glass  legs.  The  charging  wires  must  bo 
about  10  inches  from  the  battery  whenever  the  high-tension  current  is 
on.  Wai  to  A:  Bartlett  and  other  manufacturers  make  an  outfit  with 
which  one  can  control  the  filament  current  and  also  the  charging  current 
from  inside  the  .r-rav-proof  booth. 

Water  must  be  added  occasionally  to  make  up  for  evaporation. 
The  life  of  a  storage-battery  is  supposed  to  be  about  two  years,  but  it 
will  become  worthless  if  left  unused  and  with  the  acid  in  the  cells  for 
several  months.  It  has  seemed  to  the  author  that  the  very  heav} 
current  demanded  for  the  Coolidge  tube  filament  quickly,  though  tem- 
porarily, reduced  the  voltage  of  a  storage-battery  and  necessitated  an 
excessive  regulation  during  the  exposure.  And  after  a  few  minutes' 
interval  during  which  none  of  the  controlling  appliances  has  been 
changed,  turning  on  the  current  will  often  produce  a  very  different 
voltage  from  the  one  shown  during  the  last  part  of  a  previous  exposure. 
Further  experience  has  shown  the  trouble  to  lie  in  the  Coolidgo  tube, 
not  in  the  storage-battery. 

But  these  considerations  were  sufficient  at  the  time  to  cause  the 
author  to  discard  the  storage-battery  and  to  install  the  following  out- 
fit, which  has  the  advantage  of  requiring  no  water,  acid,  recharging,  or 
renewals : 

Motor  generator  and  transformer  for  furnishing  the  filament  cur- 
rent. Wo  require  a  current  of  12  volts  and  3->  to  -U  amperes,  and  it  is 
immaterial  whether  this  is  alternating  or  direct.  The  necessity  that 
the  wires  leading  to  the  filament  should  also  transmit  the  high-tension 
current  makes  it  ordinarily  impossible  to  make  immediate  use  of  the 
electric-light  current  regulated  by  a  simple  rheostat.  If  the  light  cur- 
rent is  direct,  we  use  this  to  run  a  motor  generator  producing  a  low- 
tension  alternating  current,  the  strength  of  which  is  regulated  by  a 
rheostat.  This  current  passes  through  the  primary  of  a  transformer 
which  is  so  thoroughly  insulated  that  over  100, 000  volts  applied  to  the 
secondary  will  not  occasion  an  escape  of  current  to  the  ground  or  to 
the  primary  wires.  It  is  not  a  transformer  whose  chief  object  is  to 
product1  a  change  of  voltage,  but  especially  to  produce  a  current  of 
electricity  in  a  separate  circuit  completely  insulated  from  the  supply 
circuit.  If  the  light  current  is  alternating  the  motor  generator  is  dis- 
pensed with,  but  the  transformer  for  supplying  the  filament  current  is 
the  same. 

In  some  modern  experiments  the  negative  pole  of  the  high-tension 
generator  has  been  grounded.  The  voltage  becomes  zero  at  the  cathode 
of  the  Coolidge  tube  and  twice  as  high  as  before  at  the  anode.  The 
negative  terminal  can  be  approached  without  receiving  a  shock  and  one 
has  to  keep  twice  as  far  away  from  the  positive  terminal.  The  latter 
fact  may  require  special  insulation  in  the  generator.  The  principal 
object  accomplished  is  doing  away  with  the  high-tension  insulation  in 
the  filament  circuit.  This  makes  it  possible  to  use  a  storage-battery 
with  a  simpler  arrangement  and  especially  to  use  the  electric  light 
current  controlled  by  a  simple  rheostat  instead  of  the  complicated 
transformer  with  high-tension  insulation. 

Dr.  ( 'oolidge1  thinks  that  the  liberation  of  electrons  by  the  immediate 
incandescence  of  the  solid  tungsten  target  accounts  for  the  fact  that 
the  standard  ('oolidge  tube  is  not    self-rectifying  to  anything  like  the 
1  Personal  communication, 


i  M:  MEDICAL    KLEC'TIUC'ITY    AM)    RONTGEN    HAYS 

same  extent  as  the  radiator  tul>e,  in  which  the  anticathode  never  be- 
comes brilliantly  incandescent. 

Very  rarely,  in  fact,  only  once1  in  the  author's  experience,  a  Ooolidgc 
tube  \vill  cease  to  transmit  high-tension  current  though  the  filament 
i>  incandescent.  The  natural  inference  when  this  happens  is  that  one 
has  neglected  to  connect  the  high-tension  wire  \vith  the  positive  ter- 
minal of  the  tube.  This  happens  in  the  best  regulated  families.  Having 
seen  to  this,  the  next  step  is  to  test  the  parallel  spark-gap  resistance 
measured  at  the  actual  terminals  of  the  Coolidge  tube,  not  at  the  gen- 
erator, as  is  ordinarily  sufficient.  It  is  desirable  also  to  test  the  current 
for  exciting  a  gas-filled  .r-ray  tube  which  will  show  by  its  fluorescence 
whether  the  proper  strength  and  direction  of  current  is  being  delivered. 


Fin.  4H9. — Grounding  a  Coolidgc  oxray  tube.     CJroi  nd  wire  from   B  or  D  makes  it 


pOS 


ssible  to  use  the  elect  ric-light  or  storage-battery  currei 

t  without  liigh-tcnsH 

n  insulation 

r   filament    incandescence,      (iround   wire   from    A   or   ( 

would   require    higl 

-tension  in- 

lation    of     storage-battery    or    transfornier    for    f 

iame 

it    i 

icandescence.       I 

using    the 

•ct  ric-light  current   for  a  grounded  Coolidgc  .r-ra 

•  tub 

•  th 

•  ]iath  of  the  fila 

cut  circuit 

ould  be  from  one  terminal  of  the  filament  transfo 

mer 

o  tl 

e  ground  connect 

in  I)  of  the 

nerator   and    the   .r-ray    tube,    to   the   filament    tei 

ninal    15. 

through   the   fila 

cut    to   the 

uncut    terminal    ]•'..  to  the  beginning  of  the  rhco> 

at,  throi 

irh   t  he  variable 

sistance  of 

i    rheor-tat   to  the  other  terminal  of  the  filament   transform 

•r  which  may  be 

'ither  posi- 

These  te.-ts  having  all  indicated  that  the  trouble  was  not  in  the  generator 
or  its  connections  will)  the  Coolidge  tube,  but  with  the  tube  itself, 
the  manufacturers  have  been  unable  to  suggest  any  remedy  except 
remaking  the  tube.  This  means  using  the  same  metal  parts  in  a  new 
glass  bull)  at  an  expense  of  fifty  dollars  and  producing  a  tube  as  good  as 
new. 

( 'ti<,l ;</<i<  I'ulii  fur  l)t  nlfil  h'ti/lnif/rii/iliii.-  A  radiator  type  of  tube  is 
made  with  a  bulb  about  '^\  inches  in  diameter,  a  closely  fitting  lead  glass 
-hield  ;md  having  it-  anticathode  stem  directly  away  from  the  patient 
its  cat hode  stem  very  short.  The  tube  may  be  more  conveniently 
•d  in  proper  po-iiion  for  radiography,  especially  of  the  lower  teeth, 


and  it  s  long  cath- 


THK    X-RAY  783 

odal  and  anodal  prolongations  neither  of  which  must  be  allowed  within 
sparking  distance  of  any  part  of  the  patient.  The  tube  shield  for  the 
standard  Coolidge  tube  is  large  and  heavy  and  the  tube  stand  has  to 
be  correspondingly  ponderous.  The  special  tube  mentioned  has  very 
great  advantages  for  use  at  the  dentist's  ordinary  operating  chair.  It 
makes  it  possible,  but  one  should  not  yield  to  the  temptation,  to  bring 
the  anticathodc  many  inches  nearer  the  skin  than  the  13  inches  which 
the  author  considers  one  of  the  necessary  precautions  against  x-ray 
burns.  And  even  at  that  distance*  it  is  always  desirable  to  use  an 
aluminum  filter  T^n5-inch  thick,  which  may  be  fastened  over  the  orifice 
in  the  shield  to  arrest  ultraviolet  rays  and  the  softest  x-rays. 

Radiator  Type  of  Coolidge  Tube. — Originally,  all  the  intense  heat 
generated  in  the  anticathode  of  the  standard  Coolidge  tube  had  to  be 
gotten  rid  of  by  radiation  through  the  perfect  vacuum  surrounding 
the  anticathode  and  its  stem.  This  is  a  very  slow  process,  and  just 
after  the  current  has  been  turned  off  and  while  the  anticathode  is  still 
brilliantly  incandescent  the  hand  can  touch  the  glass  wall  of  the  tube. 
The  same  proximity  in  the  open  air  would  produce  an  unbearable  burn, 
but  the  vacuum  acts  as  a  poor  conductor  and  keeps  the  heat  in  the 
anticathode  to  a  great  extent.  The  radiator  type  of  Coolidge  tube 
has  means  for  rapidly  conducting  the  heat  from  the  copper  block  with  a 
tungsten  insert  which  forms  the  anticathode  along  a  thick  solid  copper 
stem  which  projects  for  3  inches  beyond  the  glass.  A  separate 
laminated  radiator  fits  over  this  metal  projection  and  with  its  large 
surface  conveys  the  heat  quickly  to  the  surrounding  air.  The  tungsten 
button  is  held  securely  by  the  fact  that  the  copper  was  melted  around 
it,  forming  a  perfect  union.  The  tungsten  button  anticathode  was 
suggested  by  the  author  for  the  purpose  of  securing  improved  radio- 
graphs of  foreign  bodies  by  reducing  the  disturbing;  x-rays  arising  from 
the  side  of  the  solid  tungsten  anticathode  of  the  standard  Coolidge 
tube.  It  had  been  tried  by  the  makers  and  found  impracticable,  but 
later,  with  the  radiation  feature,  it  has  proved  a  success. 

A  heavy  current,  however,  would  fuse  or  even  vaporize  copper 
pinfeed  so  near  the  focus  spot.  So  the  10-milliampere  radiator  tube 
with  a  3 4- -inch  bulb  is  designed  to  carry  only  10  milliamperes  with  a 
5-inch  parallel  spark,  or  any  other  combination  of  milliamperes  and  spark- 
gap  which  multiplied  together  will  make  50.  And  the  30  ma.  radiator 
Coolidge  tube  also  with  3f-inch  bulb  is  intended  for  30  ma.  with  a  5- 
inch  spark  or  any  other  combination  whose  product  is  150;  for  instance, 
25  ma.  with  a  (i-inch  spark. 

These*  are  the  rules  given  to  the  author  by  Dr.  Coolidge.  But  the 
author  finds  it  a  better  rule*  to  consider  the*  spee-ifieel  milliamperage  as 
the'  sole*  guide*,  ami  finds  that  an  increases!  milliamperage  with  a  reeluced 
voltage  means  overheating  with  possible  destruction.  There  is  no  e>b- 
jection  when  an  increased  voltage*  is  use>el.  The*  e-opper  and  tungsten 
target  should  neve*r  be  Iwtter  than  a  e-he*rry  ml  for  fear  of  vaporizing  the 
copper.  \\  he*n  this  exvurs,  a  deposit  of  coppe'r  cove*rs  the  whole  inte*rior 
of  the*  glass  bulb  and  the  tube  is  use'le*ss.  This  type  e>f  tube*  is  inteneled 
for  radiography  alone*.  It  will  not  stanel  the  long-continueel  brilliant 
incandescence  e>f  the*  anticathode  se>  readily  borne  by  the  solid  tungsten 
target  in  ele*e*p  rontgenotherapy.  It  had  better  neve*r  be  incandescent. 

Radiography  of  various  parts  of  the*  head,  trunk,  ami  extremities 
with  the'  radiator  tube  shows  emlv  slight  diftVre'nces  from  those1  maele 


7S4  MKD1CAL    KLK(  THICITY    AND    RONTCKN    RAYS 

with  the  standard  Coolidge  tube  except  that  due  to  the  ability  to  em- 
ploy the  anticathode  with  a  finer  focus.  This  is  doubtless  due  to  the 
fact  that  in  all  these  cases  the  secondary  radiation  from  the  patient's 
tissues  is  such  a  disturbing  factor  as  to  overshadow  the  differences  in 
the  radiation  from  the  tube.  The  way  in  which  the  author  expected 
the  benefit  to  beappanient  was  in  radiography  of  foreign  bodies  especially 
when  combined  with  a  means  of  arresting  secondary  rays  arising  in  the 
tissues. 

The  radiator  tuUe  is  especially  desirable  for  repeated  radiographs 
within  its  capacity  a-  to  current.  It  does  not  undergo  the  accumulation 
of  heat  which  makes  it  necessary  to  allow  a  standard  Coolidge  tube  to 
cool  while  it  is  alternated  with  others  in  making  a  series  of  radiographs. 
With  the  author's  technic  (see  Exposure  Table  p.  H'.Mi)  the  anticathode 
does  not  become  incandescent,  and  any  number  of  radiographs  can  be 
made  at  interval  of  one  minute  or  more. 

There  is  no  good  reason  for  ever  turning  on  the  power  on  open 
circuit.  With  an  .r-ray  tube  in  the  secondary  circuit  the  effect  varies 
according  to  the  resistance  of  the  tube.  An  electron  discharge  x-ray 
tube,  such  as  the  Coolidge  tube,  without  incandescence  of  the  electron 
discharge  filament,  behaves  exactly  like  an  open  circuit,  and  so  does 
a  gas-filled  tube  with  an  excessively  high  degree  of  vacuum.  Both 
varieties  of  x-ray  tube  in  a  condition  to  transmit  the  high-tension 
current  have  a  similar  ef'fectTentirely  different  from  open  circuit.  With 
the  same  control  of  the  primary  current  the,  voltage  of  the  secondary 
current  is  lowered  and  the  milliamperage  increased  by  increasing  the 
conductivity  of  the  x-ray  tube.  This  is  easily  accomplished  with  the 
Coolidge  tube  by  simply  turning  on  more  filament  current  and  so  in- 
creasing the  incandescence  of  the  filament,  and  with  the  gas-filled  tube 
by  lowering  the  vacuum. 

The  simplest  Coolidge  tube  and  generator  technic  is  available  with 
a  generator  with  only  a  single  ratio  of  transformation  and  only  one  ad- 
justment of  power  and  only  one  adjustment  of  the  filament  current  in 
the  Coolidge  tube.  The  x-ray  outfit  recommended  for  dentists  is  of 
this  character:  and  turning  it  on  automatically  produces  x-rays  of  a 
qua  lily  and  intensity  corresponding  with  reasonable  accuracy  to  5-inch 
spark  and  10  rnilliamperes. 

With  the  Coolidge  tube  apparatus  usual  in  x-ray  laboratories,  one 
must  know  the  spark-gap  and  milliamperage  that  are  suitable  for 
the  case  in  hand:  also  what  adjustment  of  transformer  power  and 
ratio  of  transformation  (if  there  is  more  than  one)  will  enable  one  to 
secure  these  factors  by  regulation  of  the  filament  current.  This  power 
and  trail-formation  adjustment  should  be  determined  with  the  Coolidge 
tube  in  operation  and  should  always  be  the  >ame.  say,  at  the  same 
buuon  of  the  rheostat  when  the  specified  sp;)rk  and  milliamperage 
are  dc-in-d.  The  extemporaneous  regulation  should  be  exclusively 
of  the  filament  current  with  one's  eye  UJHUI  either  the  milliampere- 
metcr  or  the  voltmeter,  whichever  is  most  conveniently  located.  If 
either  of  these  i-  correct  the  other  automatically  remains  so,  just  as 
either  end  of  a  U-ver  controls  the  other  end. 

Man  i //I/In/ inn  of  ////  Coolitlijc  TII!>I  irith  tin  Author'*  (',<  aerator  of 
C/in.-t/i  nt  ll/tjli-ti  usiini  Current,  or  irith  ft  Trnnfiformcr  <DI<!  High-ten- 
sion l\'i  ctijii  r.  /•'//•.-/.  t tie  filament  current  is  turned  on  and  regulated 
to  the  amperage  -ho\vn  by  previous  record-  to  produce  the  proper 


THE    X-RAY  785 

degree  of  incandescence  for  the  case  in  hand.  The  danger  to  the  ap- 
paratus from  turning  on  a  strong  current  on  open  circuit  or  with  the 
tube  in  no  condition  to  transmit  the  current  is  the  chief  reason  for 
starting  the  filament  incandescence1  first. 

Second,  the  motor  generator  is  started  and  its  speed  gradually  in- 
creased to  the  maximum  by  a  switch  and  a  rheostat. 

Third,  the  rheostat  which  will  control  the  primary  current  in  the 
transformer  is  set  at  the  proper  resistance  button  for  the  case  in  hand. 

Fourth,  the  primary  current  is  turned  on  by  closing  a  thrce-bladed 
knife  switch;  and  the  secondary  current  at  .once  traverses  the  x-ray 
tube  and  produces  x-rays. 

Fifth,  at  the  end  of  the  required  exposure  the  primary  current  is 
turned  off;  the  motor  generator  stopped,  and  the  filament  current  turned 
off. 

The  high-tension  current  through  the  x-ray  tube  must  always  be 
the  last  thing  to  be  turned  on  and  the  first  thing  to  be  tinned  off.  This 
rule  applies  to  the  use  of  the  Coolidge  tube  with  any  type  of  generator. 

During  an  exposure  of  a  few  seconds  or  more  one  notices  the  volt- 
age of  the  high-tension  current  and  regulates  it  if  it  varies  from  the 
desired  figure.  There  is  no  occasion  for  noting  both  the  voltage  and 
the  milliamperage  because  with  a  certain  adjustment  of  the  generator 
any  particular  voltage  inevitably  produces  a  certain  milliamperage  and 
both  are  simultaneously  regulated,  one  up  and  the  other  down,  by  varying 
the  strength  of  the  filament  current.  One  should  not  move  the  power 
lever  of  the  x-ray  generator,  but  the  filament  rheostat  for  this  purpose. 

Manipulation  of  the  Coolidge  Tube  with  an  Induction  Coil  or  with  a 
Static  Machine. — First,  turn  on  and  regulate  the  filament  current. 

Second,  make  the  exposure  by  turning  on  the  proper  power  from  the 
coil  or  static  machine. 

Third,  turn  off  the  coil  or  static  machine. 

Fourth,  and  last  of  all,  turn  off  the  filament  current. 

Occasion  may  arise  to  change  tubes  without  altering  the  relation 
of  the  tube  to  the  patient  and  with  the  plate  in  place.  It  is  of  advantage 
to  be  able  to  properly  regulate  the  spark  equivalent  of  the  second  tube 
without  turning  on  the  high-tension  current  and  so  exposing  the  plate 
to  the  x-ray.  With  two  standard  Coolidge  tubes  both  warmed  by  recent 
exposures  the  adjustments  may  not  have  to  be  changed.  But  with  a 
standard  Coolidge  tube  and  one  of  the  radiator  type  a  radical  change 
may  have  to  be  made  with  the  filament  rheostat  to  make  the  filament 
current  the  same:  which  will  usually  produce  the  right  effect  upon  the 
spark  equivalent  of  the  tube. 

Destruction  of  a  80-milliampere  Kadiator  Coolidge  Tube  Through 
Orcrhi'dting. — This  occurred  to  the  author  in  making  a  kidney  radiograph 
of  a  l.")0-pound  man,  upon  a  Seed  x-ray  plate  without  an  intensifying 
screen.  Spark  equivalent  .">  inches,  30  milliamperes.  forty-five  seconds. 
The  entire  anticathode  became  red  hot  and  a  considerable  part  of  the 
copper  in  contact  with  the  distal  portion  of  the  tungsten  melted  and 
dropped  down  upon  the  glass  wall  of  the  tube.  At  the  moment  this 
occurred  there  was  a  marked  fall  in  the  resistance  of  the  tube  indicated 
by  an  increase  in  milliamperage.  The  current  was  immediately  turned  oft'. 
The  picture  was  perfect,  showing  calculi  in  both  ureters.  The  tube  had 
been  securely  clamped  at  both  end.-.  Although  the  lower  part  of  the 
tube  was  splashed  all  over  with  copper  the  tube  held  together  until  it 
50 


780  MEDICAL    ELECTRICITY    AND    RONTdEN    HAYS 

hud  been  removed  from  the  shield  and  then  the  hull)  broke  all  to  pieces. 
Evidently  this  exposure  was  a  little  too  long  for  the  tube  to  stand  that 
strength  of  current  without  an  interval  for  cooling.  The  unticathode 
of  the  radiator  Coolidge  tube  should  not  be  allowed  to  get  hotter  than 
a  dull  red  heat.  And  Dr.  ( 'oolidge  advises  a  limit  of  fifteen  seconds 
with  this  strength  of  current. 

The  Author'*  Precaution*  in  Case  of  Brealcai/e  of  the  x-Raij  Tube. — 
An  occurrence  such  as  the  above  might  have  disastrous  consequences 
if  a  part  of  the  tube  still  charged  with  high-tension  electricity  were  to 
fall  upon  the  patient.  And  equally  to  be  avoided  is  the  possibility 
of  the  red  hot  anticathode  dropping  upon  the  patient.  The  tube  is 
always  enclosed  in  a  tube  shield  of  very  thick  lead  glass  and  both  the 
anodal  and  the  cathodal  prolongations  are  securely  clamped.  And 
covering  the  opening  in  the  metal  base  of  the  tube-holder  is  a  sheet  of 
hard  aluminum  1  mm.  thick  which  would  prevent  anything  from  falling 
upon  the  patient.  This  aluminum  acts  also  at  all  times  as  a  filter  to 
protect  the  patient  from  very  soft  x-rays  and  trom  ultraviolet  rays. 

Our  Adrantaye  Claimed  for  a  Gax-fdled  x-h'ai/  Tube. — The  focus 
point  may  be  much  smaller,  and  consequently  it  is  possible  to  secure 
-lightly  better  definition.  This  is  thought  to  be  because  a  cathode 
stream  made  up  of  ions  or  charged  atoms  a  million  times  the  size  of 
the  electrons  which  form  the  cathode  stream  in  the  electron  discharge 
lube  does  not  penetrate  the  target  to  anywhere  near  the  same  extent. 
It  should  be  noted,  however,  that  a  Coolidge  tube  excited  by  a  direct 
constant  high-tension  current  has  the  same  properly. 

Inverse  Discharge.— Some  tubes  will  show  the  effect  of  the  inverse 
discharge  by  lacking  the  sharp  division  into  a  light  and  a  dark  hemi- 
-phere  and  by  an  irregularity  in  the  ray  produced.  This  inverse 
discharge  is  a  current  produced  in  the  secondary  coil  by  the  ''make" 
in  the  primary  current.  Whenever  a  current  begins  to  flow  through 
the  primary  coil  an  induced  current  is  generated  in  the  secondary  coil, 
;md  this  is  much  weaker  than  the  "break"  current  and  in  an  oppo- 
-ite  direction  to  it.  This  inverse  discharge  may  not  produce  a  noticeable 
effect  if  the  vacuum  in  the  tube,  the  nature  of  the  interruptions,  the 
strength  of  i  he  primary  current  and  the  self-inductance  in  the  primary 
coil.  ;ind  the  adjustment  of  the  condenser  are  all  harmonious.  When 
it  does  Liive  trouble,  it  may  be  cut  out  by  a  spark-gap  across  which 
tlic  -econdurv  current  has  to  leap  in  pus.-mg  ironi  each  pole  ot  the 
coil  to  the  corresponding  tip  of  the  tube.  These  are  properly  called 
series  spark-gups  as  distinguished  from  the  parallel  spark-gap  directly 
between  the  two  poles  of  the  coil  by  the  length  of  which  the  resistance 
and  hence  the  degree  of  vacuum  in  the  tube  is  measured.  'The  name 
multiple  spark-gups  is  applied  to  an  arrangement  by  means  of  which 
thi-  '-urn-tit  mav  be  made  to  leap  across  from  one  to  six  or  eight  short 
gaps  on  its  \vay  to  tin-  tube.  It  is  doubtful  whether  this  has  any 
advantage  over  the  simpler  single  gap  of  adjustable  distance;  like  the 
OM<-  devised  by  the  author.  Resides  cutting  out  the  inverse  discharge 
leap  across  a  space  of  over  ;m  nidi  the  spark-gap  has 
vent  overheating  the  tube  and  enables  us  to  use  a 
vacuum  is  a  little  too  low.  It  does  not  raise  the 
oduces  a  ruv  of  a  little  more  penetration  corresponding 
uum, 
penal  wav  of  cuttinu  out  the  inverse  discharge  is,  bv  the 


IM.ATE    ii 


PI.ATH    12 


THE    X-RAY 


787 


use  of  a  ventril  or  valve  tube.  'Phis  is  a  vacuum  tube  of  about  the 
same  size  as  an  x-ray  tube  and  has  a  regulator  for  maintaining  the 
right  degree  of  vacuum.  Its  positive  and  negative  poles  are  differently 
shaped.  One  of  the  wires  from  the  x-ray  coil  passes  to  one  tip  of  the 
ventril  tube;  the  current  passes  through  the  ventril  tube  and  then 
through  a  wire  passing  from  the  other  tip  to  the  x-ray  tube.  This  is 
quite  a  certain  remedy  for  the  inverse  discharge,  but  is  not  an  essential 
part  of  an  x-ray  equipment. 

Ventril  or  Valve  Tubes. — One  pole  of  the  Yillard  ventril  tube  is 
made  of  a  spiral  of  aluminum  presenting  a  very  large  surface;  for  the 
origin  of  cathode  rays.  This  pole  acts  readily  as  a  cathode;  and  the 
ventril  tube  permits  the  passage  of  currents  (lowing  in  such  a  direction 
that  this  pole  is  the  negative  one.  The  other  pole  is  made  of  a  small 
straight  rod  of  metal  almost  completely  ensheathed  in  glass  and  pre- 
senting a  minimum  surface  for  the  origin  of  cathode  rays.  The  tube 
will  hardly  transmit  any  currents  which  pass  in  such  a  direction  that 
this  becomes  the  negative  pole  of  the  tube. 

If  ventril  tubes  are1  used  two  of  them  should  be  provided  and  there 
are  several  different  possible  arrangements.  One  may  be  connected 


Co,  I        


Fig.  ")00. — Single  ventril  tube  connected  in  series  with  the  cathode  of  the  .r-ray  tube. 

with  either  pole  of  the  coil  in  such  a  way  (Fig.  500  or  Fig.  501)  that  the 
spiral  of  the  ventril  tube  is  connected  either  with  the  anode  of  the  tube 


Coil    4- 


Fie;.  .")()!. — Single  vontril  tube  connected  in  series  with  the  anode  of  the  .r-ray  tube. 

or  with  the  negative  pole  of  the  x-ray  coil.     Or  a  ventril  tube  may  be 
interposed   between   each    pole   of   the  x-ray   coil  and  the  appropriate 


Fiji.    ~>0'2. — Ventril    tubes    between 


the  poles  of  the  coil  and  the  tormina! 


Fig.  .")():>. — Ventril  tube  between  the  poles 
of  the  coil.     Two  may  be  used. 


pok1  of  the  x-ray  tube,  as  in   Fig.  ">02,  taking  car*1  to  have  the  correct 
poles  of  the  two  ventril  tubes  directed  as  specified  above. 


788 


MKDICAL    KLKCTHICITY    AND    HOXTdK.N    HAY 


The  third  arrangement  which  should  be  provided  for  is  to  have  one 
or  t\vo  veiitril  tubes  placed  between  the  two  poles  of  the  x-ray  coil,  as 
in  Kit:.  -">()o.  During  the  normal  discharge  of  the  coil  practically  no 
current  passes  through  the  ventril  tube,  but  during  the  in  verse  discharge, 
when  the  polarity  of  the  induction-coil  is  the  reverse  of  that  shown  in 


the  diagram,  practically  all  the  current  pusses  through  the  ventril  tube. 
This  occurs  because  the  resistance  of  the  ventril  tube  to  the  passage 
of  a  current  in  this  direction  is  very  much  less  than  that  of  the  .r-ray 

tube. 

This  arrangement  has  been 
adopted  by  <  I  a  iff  e  for  his  trans- 
former, which  is  actuated  by  an 
alternating  current  without  an 
interrupter.  The  discharge  is 
alternating,  the  impulses  in  OHM 
direction  pass  through  the  ven- 
t  ril  tube  and  t  hose  in  the  other 
and  proper  direction  through  the 
r-ray  t  ube. 

The  Author's  Arrangement 
of     Spark-gaps     and     Ventril 
Tubes.  —  Kach  pole  of  the  .r-ray 
coil  '  Fi^r.  .">(>.">    ha-  a  short  metal 
base     upon     which    is    seciireil    a 
'Jass    roil    about     1    inches   long 
and    at     the    end    of   this    rod    is 
'   •  '  '    "'    '•''••''  •''      a  metal  at  tachment  for  the  con- 
ducting cord  leading  to  one  pole 
metallic   rod   operated  by  an 
1   -'i  as   in   make  a   direct    con- 


THE    X-KAY 


789 


to  the  .r-ray  tube  In'  bridging  across  the  insulated  space  represented 
by  the  "lass  rod.  Or  this  metal  rod  may  be  turned  back  a  little  so  that 
this  space  is  not  quite  bridged  over  and  the  current  has  to  leap  across  a 
spark-gap  in  passing  from  the  coil  to  the  tube.  Or  the  metal  rod  may 
be  turned  back  to  the  connection  that  leads  to  one  of  the  ventril  tubes. 
A  ventril  tube  is  held  over  each  pole  of  the  coil  by  a  wooden  bracket  and 
its  poles  art-  permanently  connected,  one  with  the  metallic  attachment 
at  the  distal  extremity  of  the  glass  rod  and  the  other  with  an  insulated 
attachment  which  can  be  reached  by  the  metal  rod  when  it  is  turned 
in  that  direction.  The  only  way  that  the  current  can  reach  this  pole 
of  the  .r-ray  tube  when  this  connection  is  made  is  by  passing  through 
the  ventril  tube.  The  same  arrangement  is  found  at  the  other  pole  of 
the  coil  and  each  can  be  operated  independently.  The  .r-ray  lube 
may  be  connected  directly  with  each  pole  of  the  coil,  or  through  a spark- 
irap  at  either  or  both  poles,  or  through  one  or  both  ventril  tubes.  It  is 
also  only  the  work  of  a  moment  to  connect  one  or  both  of  the  ventril 
tubes  between  the  two  poles  of  the  .r-ray  coil. 

Yentril  tubes  become  overheated  and  break  if  the  current  is  forced 
through  them  in  the  wrong  direction.  Kven  in  the  right  direction  they 
will  not  stand  the  heavy  currents  often  used  in  radiography.  The  author 


Fin.  507. — Current  in  the  inverse  direction 


resistance  and  longer  spark  equivalent 


finds  them  useful  in  radiotherapy  arranged  in  series  with  the  .r-ray  tube 
it'  the  latter  shows  a  tendency  to  inverse  current,  and  arranged  across 
between  the  poles  of  the  .r-ray  coil  in  radiography,  but  ninety-nine 
times  out  of  a  hundred  they  are  not  required. 

A  ventril  tube  used  in  series  with  an  .r-ray  tube  producing  rays 
Xo.  \  or  o  Henoist  and  consequently  of  proper  condition  for  renal 
radiography  should  present  a  pale  rose  carmine  color  inside  the  alumi- 
num spiral,  the  inside  wf  the  large  part  of  the  lube  should  present  a 
rose-mauve  color  which  becomes  more  pronounced  toward  the  con- 
tracted part  of  the  tube  and  changes  to  a  clear  rose  color.  At  the  anode 
there  is  a  brilliant  pink.  In  the  prolongation  into  which  the  aluminum 
spiral  extends  there  should  be  a  faint  red.  not  a  green  color,  while  the 
tube  is  in  operation. 

Regulation  of  a.  Ventril  Tube. — For  most  purposes  a  ventril  tube 
should  have  a  resistance  in  the  proper  direction  equal  to  a  spark-gap  of 
about  1  or  '2  millimeters  (^-.-  to  -J-.-  inch\  while  in  the  reverse  direction 
its  resistance  should  be  from  1  to  7  centimeters  (\\  to  2  or  3  inches'). 
The  degi'ee  of  vacuum  is  regulated  by  means  of  a  spark  regulator,  as 
in  Fi<r.  .~>(H'>,  or  in  other  ventril  tubes  bv  ln-ating  the  osmo-regulator. 

The  Wehnelt  Valve  or  Ventril  Tube. — This  is  a  vacuum  tube  in 
which  the  cathode  is  composed  of  an  infusible  substance  like  carbon. 


'90 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


platinum,  or  tantalum  covered  with  a  metallic  oxid.  When  such  a 
cathode  is  red  hot  a  difference  of  potential  of  IN  or  '_'()  volts  will  send  a 
current  through  the  tube  in  one  direction,  but  it  takes  ;•>()()  volts  to  send 
a  current  through  in  the  other  direction. 

It  may  be  used  to  rectify  an  alternating  current  to  be  supplied  to  a 
\\ehnelt  interrupter  and  the  primary  of  an  induction-coil. 

Such  a  valve  tube  may  be  used  to  rectify  triphase  currents.  It 
requires  three  anodes  connected  with  the  three  active  wires  and  a  single 
cathode  connected  with  the  neutral  point.  The  current  is  then  con- 
verted into  a  unidirectional  pulsating  one. 

The  Ondoscope  or  Oscilloscope  (Tig.  508  L-  This  is  a  glass  tube 
about  TJ  inches  long  and  about  1  ',  inches  in  diameter,  closed  at  both  ends. 


IML'.  .~>ON.— Hi 


where  electrodes  are  sealed  in  the  glass  and  exhausted  to  the  (ieissler 
degree  ot  vacuum.  This  is  equal  to  :•>  or  I  millimeters  of  mercury  or  a 
pressure  of  -j— MM!  or  T"iV!iT77  °f  an  atmosphere.  The  electrodes  almost 
meet  in  the  middle  of  the  tube,  coming  to  within  r,1^  inch  of  each 
other,  where  the\'  may  be  separated  by  a  vertical  partition  made  of 
porcelain  or  mica,  but  in  which  there  is  a  small  central  hole.  The 
pan  11  ion  is  not  necessary.  Any  voltage.-  above  .'•>()()  cause  the  tube  to 
Imlit  up  around  the  end  of  one  or  both  of  the  electrodes.  The  tube 
does  not  materially  impede  or  affect  the  character  of  any  of  the  high- 
tension  currents  which  it  is  designed  to  studv.  (See  also  page  73S. ) 

It  forms  part  of  the  circuit  which  is  to  be  tested  as  to  the  magnitude 
and  direction  of  high-tension  currents.      Placed  in  series  with  an  .r-rav 


IliJIII  III 


tube  ;i  mass  of  violet  light  is  seen  to  surround  one  electrode,  while  very 
little  is  around  the  other  if  there  is  little  inverse  discharge.  Looking  at 
(lie  viol'-t  liniit  m  a  rapidlv  revolving  mirror  it  is  seen  to  consist  of 
-eparate  flashes  of  li^ht  :  larger  one.-  in  one  direction,  and  alternate 
-mallei  one.-  iii  the  o'tlier  direction.  A  photograph  made  with  the 
ondo-c-)pc  I-'IH.  .")()' ij  furni.-hes  a  chart  which  shows  the  nature  and 
..•••'••  ion  of  i  he  i  lischarges.  l.ediic  and  Morm'  Use  t  he  following  method 
,i;  tnakiim  these  photographs:  A  lens  i-  placed  near  the  ondoscope 
itli  the  openim:  in  a  diaphragm.  The  room  is  absolutely 
md  a  photographic  plate  i-  held  at  siidi  a  distance  that  the  image 
i-  Fnru. -pd  upon  it.  Moving  the  plate  laterally  secures  a  series  of 
linage-  ni  the  successive  flashes  ot  liirht. 


THE    X-RAY  791 

The  ( 'akhvcll-Simon  interrupter  gives  better  tracings  (Fig.  509)  than 
the  Wehnelt  and  most  others. 

A  very  curious  fact  was  brought  out  by  varying  the  conditions  in  a 
mercury  jet  interrupter.  The  currents  from  the  secondary  coil  become 
unidirectional  when  the  duration  of  the  period  of  closure  is  sufficiently 
small  compared  with  the  total  time  of  a  complete  period. 

This  fact  seems  to  the  author  to  be  suggestive  of  the  practicability 
of  so  timing  a  mechanic  interrupter  as  to  secure  unidirectional  sec- 
ondarv  discharges  from  an  .r-rav  coil. 


The  Author's  Method  of  Ondoscopic  Photography. — An  ordinary 
camera  is  placed  upon  a  stand  upon  which  it  may  be  turned  from 
side  to  side.  It  is  focused  upon  the  ondoscope,  placed  in  a  vertical 
position,  before  the  current  is  turned  on.  Then  the  room  is  darkened, 
the  camera  is  turned  to  one  side,  and  its  diaphragm  is  opened.  The 
current  is  now  turned  on  and  the  camera  turned  quickly  around.  Its 
diaphragm  is  closed  as  soon  as  it  has  completely  passed  the  ondoscope. 

SECONDARY  RAYS 

These  are  .r-rays,  usually  of  moderate  intensity,  which  arise  from 
contact  of  the  .r-rays  or  the  cathode  rays  with  any  solid  or  liquid  sub- 
stance. They  radiate  from  all  parts  of  the  .r-ray  tube  and  from  everv 
portion  of  a  solid  or  liquid  substance  traversed  by  the  .r-rays.  Secondary 
rays  from  the  .r-ray  tube  may  be  called  extra  rays. 

The  intensity  of  the  secondary  rays  from  different  substances  has 
been  found  by  .1.  J.  Thomson1  to  be  in  proportion  to  their  atomic 
weights,  except  in  the  case  of  nickel,  which  is  the  same  as  copper  in  this 
regard. 

Secondary  Rays  from  an  Aluminum  Screen  for  Soft  Rays.— 
Secondary  rays  of  slight  penetration  arise  from  an  aluminum  screen 
and  are  absorbed  by  the  skin  and  have  a  tendency  to  create  dermatitis. 
They  may  be  arrested  by  covering  the  surface  of  the  aluminum  screen 
toward  the  patient  with  card-board  or  thick  black  paper. 

Derma  Rays.  --This  is  the  name  sometimes  applied  to  secondary 
rays  of  slight  penetration  arising  from  the  impact  of  the  cathode  parti- 
cles with  the  molecules  of  gas  contained  in  an  .r-ray  tube  or  with  the 
li'lass  walls  of  the  tube.  They  are  rays  of  slight  penetration  and  are 
similar  to  the  secondary  rays  which  are  generated  in  the  skin  from  the 
impact  of  the  .r-rays.  They  expend  all  their  energy  upon  the  skin: 
1  I'roc.  Comb.  Pliil  Sot'.,  vol.  \iv,  1007,  p.  lO'.t. 


792 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


hence  the  name  derma.     These  are  some  of  the  rays  which  are  arrested 
by    protective    filters    for    soft    rays. 

Experiments  Upon  Secondary  Rays. — An  experiment  may  be 
made  in  which  the  photographic  plate  in  its  light-proof  envelopes  is 
held  with  its  uncoated  surface  toward  the  .r-ray  tube  and  with  strips 
of  platinum,  lead,  /me,  and  aluminum  held  at  the  film  side  of  the  plate. 
The  plate  is  much  more  darkened  in  front  of  the  platinum,  lead,  or  /ino 
strips  than  elsewhere.  It  seems  like  a  reflection,  but  is  probably  due 
to  the  development  of  secondary  rays  from  the  metal  surfaces. 
Aluminum  gives  rise  to  hardly  any  such  effect,  but  a  thin  sheet  of 
aluminum  between  the  platinum  and  the  photographic  plate  does  not 
prevent  the  effect  of  the  secondary  rays  which  arise  from  the  platinum. 


u.  .Ml.  —Experiment  in  halation,      rilin  ii] 


Fiu;s.  ~>1  1  and  .~>12,  made  by  the  author  Dec..  !!»()  1,  show  the  results. 
A  pair  of  shears  were  laid  upon  a  photographic  plate  enclosed  in  black 
Mini  orange  envelopes.  In  the  first  the  film  side  of  the  plate  was  up 
Miid  in  the  other  it  was  down.  In  Fig.  511  a  certain  part  of  the 
plate  h;id  a  sheet  of  glass  over  it  and  wood  under  it.  This  part  of  the 
plate  was  lenst  acted  upon  by  the  .r-ravs.  The  other  two  portions  of 
'In-  plale  were  more  acted  upon.  One  had  wood  under  and  nothing 
but  the  paper  envelopes  f»ver.  and  the  third  part  had  sheet  tin  under 
and  n< )'  lnii'j  but  paper  envelopes  over.  The  plale  with  the  film  side 
d'i\vn  Fin'.  .">  \'2  -howed  t  he  least  effect  from  t  he  ./'-rays  at  a  port  ion  with 
uder  and  nothing  over.  The  next  to  the  least  effect  was  where 
there  \va.~  l<-M<l  under  and  nothing  over,  and  the  greatest  effect  was 
where  there  \va-  wood  under  and  nothing  fiver. 

( 'ou  n  ad< ''s  experiment  s.1  with  t  in,  lead,  copper,  and  aluminum  placed 


THE    X-RAY 


793 


under  a  photographic  plate  exposed  to  the  x-ray  show  that'  tin  gives 
much  more  secondary  rays  than  the  others  and  aluminum  gives  practi- 
cally none.  Tin-foil  may  be  spread  over  the  sensitized  surface  which 
is  turned  away  from  the  x-ray  tube  in  order  to  secure  the  effect  of  an 
intensifying  screen.  This  would  succeed  better  with  a  celluloid  film 
than  with  a  glass  plate,  because  with  the  latter  the  glass  would  inter- 
cept a  certain  part  of  the  rays.  Nothing  is  so  good  as  a  lead  screen  for 
the  purpose  of  preventing  secondary  rays  from  reaching  the  plate  from 
objects  behind  it. 

Experiments  by  Kaye1  indicate  that  screens  of  different  metals  are 
especially  transparent  to  rays  originating  from  an  anticathode  of  the 
same  metal  or  of  a  metal  with  a  similar  atomic  weight.  He  also  finds 
that  with  an  aluminum  screen  and  anticathodes  of  different  metals  the 


\-\i:.  ~>\'2. — Experiment   in  halation.     Film  down.      Different  substances  over  and  under 
the  plate  outside  of  its  light-proof  envelopes. 

degree  of  opacity  is  almost  directly  proportional  to  the  density  of  the 
different  anticathodes.  The  theory  is  advanced  that  the  x-rays  arise 
partl\"  in  the  deeper  layers  of  the  anticathode  and  undergo  a  certain 
filtration  in  emerging  from  it.  so  that  the  rays  which  radiate  from  it 
are  largely  those  To  which  the  particular  metal  is  especially  transparent. 

Lead  transforms  x-rays  into  more  absorbable  x-rays.  Aluminum 
does  not:  hence  a  lead  and  an  aluminum  screen  are  more  opaque 
than  an  aluminum  and  a  lead  one.  Observations  throw  doubt  upon 
this. 

This  is  true  of  polonium  rays,  but  hardly  demonstrable  with  radium. 

Diaphragms  for  the  Suppression  of  Extra  Rays. — Rays  originate 
from  almost  every  part  of  the  tube,  and  cause  the  image  to  be  sliulnly 

'Arch.  Rfmtijyn  Hay,  Xo.  M.  April.  I'.ms. 


iy*  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

blurred  as  compared  with  an  ideal  condition  limited  entirely  to  the 
rays  radiating  from  the  focus-point  on  the  anticathode.  And  it  is 
possible  by  means  of  an  ordinary  diaphragm  or  series  of  diaphragms, 
or  by  means  of  Albers  .Schoiiberg's  compression  cylinder  and  diaphragm 
cylinder,  or  by  means  of  the  present  author's  cellular  screen,  to  practi- 
cally do  away  with  the  effect  of  these  extra  rays  from  the  tube. 

An  ordinary  diaphragm  may  be  made  of  .r-rn;/  metal  or  of  lend  or 
zlni-  in  any  suitable1  support  and  with  an  opening  which  may  be  varied 
according  to  the  necessities  of  the  case.  It  may  have  the  somewhat 
complicated  arrangement  called  the  iris  diaphragm,  by  means  of  which 
the  opening  is  varied  from  the  largest  to  the  smallest  by  the  synchronous 
motion  of  a  do/en  different  sections  and  the  opening  always  remains 
circular. 


Aii  ordinary  diaphragm  which  I  find  very  satisfactory  is  that, 
furni-h'-d  by  the  I-'rii  dhmdn-  shii  I/I .  This  is  a  case  which  extends  about, 
two-thirds  around  the  ./'-ray  t  ube.  and  is  made  of  frit  lined  with  white 
lead,  which  i-  opaque  to  the  J"-ravs.  There  is  an  opening  opposite  the 
aniiralhode  to  allow  the  exit  of  rays  emer^in.^  at  a  right  angle  to  the 
loni:  axis  of  the  tube.  The  opening  is  at  a  distance  of  I1,  inches  from 
tin-  anticathode  and  is  '_' ',  inches  in  diameter.  It  may  be  reduced  in 
-i/e  by  the  introduction  of  smaller  diaphragms  or  of  tubular  prolonga- 
tions which  can  be  introduced  into  the  mouth,  rectum,  or  vagina,  and. 
of  cour.-e,  are  especiullv  intended  for  treatment.  The  ./'-ray  tube  is 
securely  fastened  in  the  Krirdlaiider  shield  and  there  is  a  stem  to  the 
shield  by  which  i;  may  be  secured  in  any  desired  position  by  the  .r-ray 
stand. 

The  Fneillandcr  -hield  affords  all  requisite  protect  ion  for  t  he  pat  lent . 


THE    X-RAY 


795 


but  does  not  shield  the  operator  from  the  continued  effect  of  the  second- 
ary rays  arising  from  the  uncovered  part  of  the  tube. 

The  Ripperger  shield  is  an  opaque  box  weighing  60  pounds  and  large 
enough  to  completely  surround  the  x-ray  tube,  and  affords  entire  pro- 
tection except  from  rays  emerging  at  an  orifice  which  can  be  varied  in 
size  by  the  application  of  cylinders  from  1  to  5  inches  in  diameter.  It 
is  suspended  from  a  sort  of  gallows  on  wheels,  so  that  it  can  be  adjusted 
at  any  height  above  or  below  the  patient  and  send  the  rays  in  any 
desired  direction. 

Similar  shield  boxes  have  been  used  by  Albers  Schonberg  and 
others,  but  the  mounting  of  this  one  renders  it  the  most  convenient  of 
all. 

Bergonie's1  method  of  protecting  the  operator  from  the  x-ray  by  having 
the  tube  close  to  the  floor,  so  that  the  operator  is  above  the  plane  of  the 


Fig.  .114. — Compression  cylinder  and  diaphragm. 

anticathode,  is  insufficient.  It  is  true  that  very  few  x-rays  radiate 
from  the  back  of  the  anticathode,  and  that  for  a  single  exposure  a 
person  is  amply  protected  if  he  is  behind  the  plane  of  the  anticathode 
and  consequently  is  not  exposed  To  the  direct  rays.  There  are.  however, 
extra  rays  arising  from  the  illuminated  surface  of  the  tube  and  also 
from  other  parts  of  it  and  from  every  part  of  the  room.  Constantly 
repeated  exposure  to  these  indirect  rays  will  surely  injure  the  operator 
sooner  or  later. 

.\llx-rx  Si'hrinhcrcj's  compression  cylinder  and  diaphragm  (Fig.  514' 
has  a  lube  of  brass  lined  with  sheet  lead  either  4  or  5  inches  in  diameter 
and  1  inches  long.  The  x-ray  tube  is  held  by  clamps  over  a  diaphragm 
of  lead  11  millimeters  thick  at  the  upper  extremitv  of  this  tube  and 
the  lower  end  of  the  cylinder  rests  upon  the  surface  of  the  body.  There 
1  ('.  R.  de  1'Acad.  des  Sciences.  1  10.  1  ,"><>(>.  June  ,">,  1 !)(),"). 


<9b  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

are  supports  by  which  the  apparatus  is  fastened  to  the  table  on  which 
the  patient  lies,  and  clamps  and  levers  by  means  of  which  the  lower 
end  of  the  cylinder  may  be  pressed  firmly  against  the  body  and  in 
exactly  the  best  direction.  It  serves  to  keep  the  part  motionless,  as; 
in  the  case  of  the  elbow  or  ankle,  and  in  addition  to  diminish  the  thick- 
ness of  tissue  in  examination  for  renal  calculi  and  other  radiographs 
of  the  abdomen.  The  effect  of  the  cylinder  is  to  cut  off  the  extra  rays 
from  a  large  part  of  the  .r-ray  tube,  depending.  I  think,  chiefly  upon 
the  position  of  the  diaphragm  at  the  upper  end  of  the  cylinder.  The 
only  direct  rays  that  can  reach  the  plate  are  those  embraced  by  two 
lines  passing  from  the  focus  to  the  opposite  sides  of  the  cylinder, 
but  these  direct  rays  would  require  no  diaphragm  or  cylinder  at 
all.  The  object  is  to  cut  off  the  indirect  rays,  and  as  regards  them 
the  diagram  of  Albers  Schonberg  is  too  optimistic.  My  own  diagrams 
show.  I  think,  that  secondary  rays  reach  every  part  of  the  plate  em- 
braced by  the  widely  radiating  lines  (Fig.  ;">22.  7»  and  that  the  ima.u'e 
of  a  point  p  (Fig.  .">22.  c), consists  of  the  point  produced  by  the  direct 
ray  obscured  more  or  less  by  a  penumbra  from  extra  rays  embraced 
between  the  two  dotted  lines.  The  amount  of  penumbra  about 
each  -point  of  the  image  produced  by  the  direct  focus  rays  is  the  same, 
whether  the  diaphragm  is  supplemented  by  a  cylinder  or  not.  and  is 
regulated  by  the  size  of  the  orifice  in  the  diaphragm  nearest  the  .r-ray 
tube.  The  two  sizes  recommended  by  Albers  Schonberg  for  use  with 
the  two  different  sized  cylinders  are  1  inch  and  H  inches  in  diameter. 
The  diameter  of  the  picture  is  4  or  5  inches  with  the  smaller  diaphragm 
and  5  or  (i  inches  with  the  larger.  All  these  facts  are  recognized  by 
Albers  Schonberg.  showing  the  impossibility  of  obtaining  theoretic  per- 
fection in  the  radiograph,  but  do  not  at  all  impair  the  value  of  the 
compression  cylinder  in  cases  where  the  lesion  can  be  so  definitely 
located  that  a  picture  .">  or  (i  inches  in  diameter  is  large  enough. 

Tht  f.V-  of  Loofah  Sjiouuc  witJi  a  Compression  Diaphragm. — This 
fibrous  material  can  be  made  up  into  a  hemisphere  about  (i  inches  in 
diameter  and  should  be  covered  with  linen.  Placed  over  the  kidney 
region  and  pressed  upon  by  the  compression  cylinder  it  displaces  some 
folds  of  the  intestine  and  empties  others  of  their  contents.  The  pressure 
also  renders  the  tissues  more  or  less  anemic,  and  in  this  way  aids  in  the 
production  of  a  deal1  picture.  This  material  is  suggested  by  St  rater.1 
I'  may  also  be  used  with  the  author's  board  compressor. 

My  own  observations  coincide  with  those  of  Albers  Schonberg.  that 
The  diaphragm,  with  or  without  a  cylinder.  limit:-  the  focus  rays  strictly 
to  those  which  are  to  form  the  .">-  or  (1-inch  picture:  and  that  in  pictures 
through  great  thickness  of  tissue  the  secondary  irradiation  from  the 
iis-ues  i.-  in  this  way  very  much  less  than  if  direct  rays  were  shining 
i  ill)  all  the  neighboring  parts  of  the  body.  The  secondary  rays 
m  the  ii'lass  walls  of  the  tube  are  probably  all  absorbed  in  passing 
'hrouirh  the  tissues,  so  that  his  diagram  may  repre.-ent  more  nearly  cor- 
:  ly  t  han  mine  the  condit  ion  which  actually  occur-  m  a  pict  ure  1  h  rough 
'he  body.  Mr  diagrams  -how  what  would  be  the  result  in  taking  a 
objects  at  a  distance  from  the  plate  but  without  much  of  a 
!  issue.  The  chest  wit  h  t  he  air-filled  luniis  would  be  such  a  case. 

A  -mall  diaphragm,  made  of  non-conducting  material,  so  that  it  may 

1  Xcitschrii't.   I'd)..   I'.Mis. 


a  -- 


THE    X-RAY  797 

be  placed  directly  in  contact  with  the  glass  wall  of  the  x-ruy  tube  and  so 
give  a  conparatively  wide  angle  of  illumination,  is  indispensable. 

The  present  author  prefers  his  own  board-compressor,  with  or  without 
an  air-filled  rubber  bag  or  a  compression  band(page  1051),  for  reducing 
the  thickness  of  tissue  and  for  immobilization  of  the  part.  It  enables  a 
full-sized  picture  to  be  made,  and  will  be  described  in  greater  detail  in 
discussing  the  radiography  of  renal  calculi. 

Cole's  observations1  upon  the  secondary  rays  from  an  x-ray  tube 
are  important  enough  to  be  stated  even  if  the  present  author  does  not 
entirely  agree  with  them: 

1.  A  new  tube  generally  does  not  give  good  radiographs,  no  matter 
what  type  of  apparatus  is  used  to  excite  it. 

'2.  This  does  not  depend  essentially  on  the  degree  of  vacuum. 

3.  A  well-made  tube  is  easily  brought  to  a  stage  where  it  will  make 
a  good  picture  if  this  seasoning  is  done  gradually  and  carefully. 

4.  As   it   improves   in   radiographic    quality   its   vacuum    is   better 
maintained. 

5.  After  considerable  service  it  is  found  difficult  to  lower  the  vacuum 
in  the  tube. 

0.  A  stage  is  finally  reached  where  one  might  suppose  that  the  tube 
would  soon  be  entirely  unserviceable. 

7.  The  tube  is  then  in  the  best  condition  for  radiography  and  will 
produce  good  pictures  for  a  long  time  to  come. 

8.  The  dark  color  of  the  glass  wall  of  the  tube  is,  according  to  Cole, 
not  due  to  a  metallic  deposit,  but   to   a   chemic   change  in  the  glass 
similar  to  that  occurring  in  tubes  containing  radium. 

Edema  of  the  Tissues  as  a  Cause  of  Lack  of  Definition  in  Radi- 
ography.— Radiographs  of  an  injured  elbow  show  the  bones  very 
much  more  clearly  if  they  are  taken  before  swelling  sets  in  or  after  it 
has  subsided.  It  would  seem  from  the  appearance  of  such  a  radiograph 
that  the  fluid  must  disperse  the  rays  to  a  great  extent,  and  not  merely 
impede  their  progress  along  straight  lines.  Lichtenstein's  experiment2 
in  making  a  radiograph  of  an  iron  bar  in  a  jar  of  water  demonstrates 
this  fact.  The  same  author  attributes  the  unsatisfactory  results  in  radi- 
ography of  the  fetus  in  utero  and  in  certain  cases  of  calculi  to  the  pres- 
ence of  the  liquor  anmii  in  the  first  case1  and  of  urine  in  the  second. 

The  following  experiment  by  the  author  shows  that  secondary  rays 
arise  from  various  parts  of  the  x-ray  tube  besides  the  direct  rays  from 
the  antieathode.  This  is  in  spite  of  the  supposed  unidirectional  char- 
acter of  the  discharges  driven  through  the  tube  by  the  static  machine: 

A  silver  dollar  was  held  up  near  to  an  .r-ray  tube  actuated  by  a 
static  machine,  and  looking  through  the  fluoroscope  a  ten-cent  piece, 
held  in  the  shadow  of  the  larger  coin,  could  be  seen  perfectly  well,  unless 
it  \vere  held  very  close  to  the  dollar.  Enough  .r-rays  passed  around 
the  edges  of  fhe  silver  dollar  to  illuminate  the  space,  which  would  have 
been  in  absouite  shadow  if  only  the  direct  ray.-  were  present. 

The  same  result  is  found  with  an  induct  inn -coil  and  either  a  Wehnelt. 
Caldwell,  or  mechanic  interrupter.  It  is  found  whether  ventril  tubes 
are  used  or  not,  and  arranging  them  in  series  at  one  or  both  poles  of  the 
.r-ray  tube  or  in  shunt  or  parallel  between  the  two  poles  does  not  prevent 
the  same  effect. 

1  Arch,  of  the  Rontgon  Ray.  No.  f)"v 

2  Munch  Alcd.  Woch.,  March  f..  lOOti.  p.  4444. 


MKDICAl.    KLKCTKICITY    AXD    KOX'R.KX    KAYS 

The  author's  radiating  diaphragm  prevents  this  while  still  giving  a 
large  field  for  radiography. 

An  ordinary  diaphragm  or  cylinder  will  prevent  it  if  the  opening  is 
very  small  but  this  gives  a  much  smaller  field  for  radiography. 

That  the  effect  is  not  due  to  rays  passing  through  the  silver  dollar, 
and  so  making  the  penny  visible,  is  shown  by  the  fact  that  when  a  large 
sheet  of  the  same  metal  is  substituted  for  the  silver  dollar  the  penny 
ceases  to  be  visible. 

A"-ray  Filter  or  Screen  for  Soft  Rays. — The  author  attaches 
UTeat  importance  to  the  screen  for  protecting  the  .-kin  from  the  less 
penetrating  rays.  It  may  consist  of  a  single  thickness  of  tin-foil  of 
which  100  square  inches  weigh  an  ounce.  A  sheet  of  sole-leather 
is  still  better,  and  the  author  employs  it  for  every  radiographic 
and  most  therapeutic  exposures.  Experiments  show  that  its  absorb- 
ent power  is  equal  to  that  of  about  1  inch  of  flesh,  and  with  a  very 
soft  tube  practically  all  the  rays  are  arrested,  as  they  are  mostly  rays 
of  little  penetration.  With  a  tube  of  medium  vacuum,  the  rays  of 
little  penetration  are  practically  all  arrested,  while  those  rays  which 
will  penetrate  several  inches  of  flesh  all  pass  through.  This  screen 
covers  the  orifice  in  a  Friedlander  or  Ripperger  shield  and  enables  the 
tube  to  be  brought  much  closer  to  the  surface  of  the  body  than  would 
be  safe  without  it.  and  arrests  most  of  the  extra  rays  arising  from  the 
tube.  It  is  a  necessity  for  cases  in  which  the  object  of  interest  is  in 
a  thick  portion  of  the  body  or  head,  but  is  very  close  to  the  plate. 
(  Ordinarily  the  .r-ray  tube  must  be  at  such  a  distance  from  the  plate 
that  the  image  of  the  portion  of  the  body  nearest  the  tube  is  almost 
as  dense  as  that  of  the  object  of  interest,  unless  the  latter  is  very  close 
indeed  to  the  plate.  By  means  of  this  screen  the  anode  is  sometimes 
brought  within  o  inches  of  the  surface  of  the  head  or  body,  and  the 
disproportion  between  the  proximal  and  distal  images  becomes  very 
great  both  in  si/e  and  density.  The  case  in  which  I  find  it  most  useful 
i-  in  radiography  of  a  fracture  of  the  skull  or  in  mastoid  disease.  In 
either  case  the  image  of  the  part  of  the  head  nearest  the  plate  is  clearer 
and  the  amount  of  exposure  to  the  r-ray s  less  than  in  the  other  way 
with  the  tube  at  a  greater  distance.  Some  other  applications  of  this 
-creen  will  be  described  in  discussing  the  radiography  of  special  regions. 

The  use  of  an  aluminum  screen  for  the  purpose  of  protection  from 
.r-rav  burn  has  not  obtained  very  great  favor,  but  probably  the  proper 
thickness  to  secure  equal  absorption  would  be  efficacious  in  the  author's 
-creen  for -oft  rays.  A  piece  of  ordinary  thick  sole-leather,  as  suggested 
by  ['fahler,  serves  admirably. 

There  i-  a  further  reason  for  the  Use  of  the 

-  in  the  fact   that   the  various  methods  of  rai 
U-  to  determine  the  quantity  of  soft   rays  sent  o 
praclicalh    only  the  amount    of  hard   rays.      Tl 

i   tube  occasionally   producing  a  greater  cutaneous   reaction   than 

\\ouid  be  expected  even  from  a  soft  tube.      Benoist's  radiochromometer 

and    the    author's    fluorometer   show    very    plainly    the   amount    of   the 

ratini!  ravs.  but  with  a  certain  amount  of  these  rays  the  amount  of 

•  --  penetrating  ravs  will  vary  between   very  wide  limits.     This  is 

notably   true   when   a   coil   i-   used,   owiuir  to   varying  conditions  in   the 

in'ir-rr  ,:  '•  :.  the  '  ibe,  and  elsewhere;   it    i-    not    true  to  such    an   extent 

of    the  produced   bv  a   -tatic  machine.      The  -creen     tor    soft     ravs 


THE    Z-RAY 


799 


absorbs  them,  whether  they  are  present  in  large  or  in  small  amounts, 
and  acts  as  a  shield  against  an  undesirable  effect  upon  the  skin  when  it 
is  desirable  to  bring  the  tube  quite  close  to  the  surface,  and  the  current 
must  be  a  powerful  one  and  the  vacuum  medium. 

There  is  one  danger  in  the  use  of  the  x-ray  to  which  attention  may  be 
called  at  this  place.  It  has  been  noted  that  with  the  tube  at  a  very 
considerable  distance  from  the  surface  of  the  body,  the  x-ray  appears 
to  act  upon  the  deep  tissues  equally  with  the  superficial  tissues,  and  in 
treating  a  cancer  of  the  breast  a  periostitis  of  the  ribs  has  been  excited; 
so  that  with  the  tube  at  too  great  a  distance  the  less  penetrating  rays 
reach  the  body  with  greatly  diminished  power,  aside  from  their  natural 


iaphragm  uscil  with  the  Ripperger  shield  in 


divergence;  while  the  more  penetrating 'rays  have  suffered  little  loss  of 
power  from  traversing  the  air;  and  any  desired  effect  produced  upon 
the  superficial  tissues  under  these  conditions  will  be  accompanied  by 
an  almost  equal  and,  perhaps,  undesirable  effect  on  the  deeper  tissues. 
This  observation  is  of  especial  importance  in  radiotherapy,  but  must 
be  borne  in  mind  whenever  the  human  body  is  subjected  to  the  action 
ot  the  .r-ray  for  either  examination  or  treatment. 

As  far  as  possible  the  important  particulars  of  every  radiograph  in 
this  book  are  given.  Neither  in  these  nor  in  any  other  ever  taken  by  the 
author,  or  under  his  direction,  has  there  ever  been  any  burn  or  even  a 
redness  of  the  skin,  and  never  any  evidence  of  any  other  undesirable 
ettect.  Accidents  of  the  kind  do  occur,  however,  and  it  seems  to  the 


800  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

author  that  the  hundreds  of  hours  which  he  and  others  have  spent  in 
experiments  with  radiographs  of  inanimate  objects,  and  the  study  of 
apparatus  and  technic,  will  afford  something  of  a  guide  to  others. 

The  use  of  the  author's  screen  for  soft  rays  with  a  Friedlander  or 
Ripperger  shield  enables  one  to  take  a  picture  safely,  does  away  with 
extra  rays  from  the  tube,  very  much  reduces  the  amount  of  secondary 
radiance  originating  in  the  tissues,  and  almost  entirely  prevents  the 
access  to  the  plate  of  secondary  rays  from  the  various  parts  of  the  room 
by  suppressing  the  general  diffusion  from  the  x-ray  tube.  Pfahler's 
leather  screen  is  usually  employed. 

A -ray  Stand,  Protective  Shield,  Diaphragm,  and  Cylinders  Used  by 
the  Author. — This  apparatus  is  made  by  Wappler,  of  New  York,  and 
the  idea  has  been  of  gradual  development.  The  tube  is  contained  in  a 
wooden  box,  coated  on  the  inside  with  a  sufficient  number  of  layers  of 
lead  oxid  to  make  it  so  opaque  to  the  x-ray  that  no  light  can  be  seen  in 
a  fluoroscope  held  close  to  the  box.  Metal  cylinders  enter  the  box  at 
the  two  ends  and  embrace  the  cathode  and  anode  prolongations  of  the 
x-ray  tube,  anil  are  adjustable  so  as  to  bring  the  focal  point  of  the  anti- 
cathode  directly  in  the  axis  of  the  diaphragm.  Electric  connection  is 
made  by  springs  enclosed  in  these  metal  cylinders  pressing  gently  against 
the  terminals  of  the  x-ray  tube,  while  the  conducting  cords  from  the  x-ray 
coil  are  attached  to  the  outer  ends  of  the  metal  cylinders.  A  number 
of  lead-glass  windows  permit  of  observation  of  the  tube1  while  in  opera- 
tion. The  box  measures  about  2  feet  long,  1  foot  high,  and  11  inches 
wide:  there  is  an  opening  4  inches  in  diameter  in  the  bottom  of  the  box, 
and  to  this  may  be  fastened  a  diaphragm  with  cross  wires  for  prelimi- 
nary use  in  placing  the  focus  of  the  tube  exactly  in  the  axis  of  the  dia- 
phragm. After  this  adjustment  the  cross-wire  diaphragm  may  be 
removed,  and  either  the  simple  4-inch  diaphragm  may  be  used  or  a 
cylinder  may  be  attached.  The  different  cylinders  are  7  inches  long 
and  are  1,  2,  3,  4,  and  o  inches  in  diameter,  respectively.  They  arc 
made  of  thick  zinc,  a  metal  almost  as  opaque  to  the  x-ray  as  lead  and 
more  rigid  than  the  latter. 

The  box  as  above  described  was  suggested  by  Dr.  Ripperger.  It 
weighs  (>()  pounds  and  is  held  by  a  stand  which  permits  the  box  to  be 
turned  in  any  direction,  to  be  raised  or  lowered,  and  moved  forward 
or  backward.  The  tube  stand  is  of  the  model  suggested  by  Birckner. 
It  is  of  wood  and  rests  on  a  broad,  flat  tripod;  a  horixontal  arm  holds 
the  box,  and  can  be  moved  back  and  forth  by  turning  the  knob  of  a 
rack  and  pinion.  This  is  useful  in  adjusting  the  tube  for  radiotherapy, 
and  especially  for  stereoradiography.  The  weight  of  the  box  and  hori- 
zontal arm  is  counterbalanced  by  a  weight,  like  a  window-sash  weight, 
which  slides  up  and  down  in  one  of  the  hollow  wooden  columns  of  the 
stand. 

An  improvement  by  the  author  allows  of  regulation  of  the  degree  of 
vacuum  without  opening  the  box.  Two  brass  knobs,  (i  inches  apart  on 
the  outside  of  the  box,  are  connected  by  springs,  one  with  the  cathode  ter- 
and the  other  with  the  regulating  device  of  the  x-ray  tube.  A 
e  wire  i-  fastened  to  one  knob,  and  may  be  bent  so  as  to  make  a 
connection  or  a  short  or  a  long  spark-gap  between  the  regulating 
.  The  cut  ire  a ppa rat  us  weighs  about  150  pounds,  but  it  has  rollers 
enable  one  u,  push  it  over  the  floor.  It  costs  about  8100. 


THE    X-RAY 


THE  AUTHOR'S    CONTACT  DIAPHRAGM 


801 


This  is  made  of  a  double  thickness  of  the  opaque  fabric  used  in  x-ray 
protective  aprons.  It  sufficiently  covers  the  anterior  hemisphere  of  the 
x-ray  tube,  and  has  a  circular  opening  3  inches  in  diameter.  The 
si/e  of  this  opening  may  be  temporarily  reduced  to  2%,  2,  l£,  or  1  inch 
by  an  iris  diaphragm,  or  by  different  sized  rings  of  the  same  material. 
The  opaque  material  employed  is  a  non-conductor  of  electricity  and  does 
not  interfere  with  the  operation  of  the  x-ray  tube  or  cause  it  to  be 
punctured. 

The  advantage  to  be  derived  is  twofold:  portability  and  increased  area 
of  illumination  with  equal  definition. 

The  diaphragm  adds  so  little  to  the  weight  that  the  tube  can  be  held 
in  an  ordinary  tube  stand. 

A  diaphragm,  D-D,  of  material  which  can  be  applied  in  contact  with 
the  wall  of  the  x-ray  tube  will  require  a  smaller  opening  for  the  same 


I'iLT.  ">lii.  — Flexible  contact  diaphragm,  forming  protective  shield  with  opening.-  of  various 

sizes. 

area  of  illumination  upon  the  photographic  plate  than  a  diaphragm, 
D'-D'.  which  must  be  placed  at  a  distance  from  the  tube  (Fig.  .~>17<. 
The  same  illustration  shows  the  smaller  area  of  the  tube  from  which  vaga- 
bond rays  may  pass  through  a  point  A".  There  is  consequently  very  little 
blurring  of  the  image  as  compared  with  that  which  would  occur  with  a 
diaphragm  placed  at  a  distance  from  the  wall  of  the  tube  (Fig.  ">lSi. 
where  the  opening  in  the  diaphragm  is  large  enough  to  give  the  same 
area  of  illumination.  To  secure  equally  good  definition  with  a  dia- 
phragm at  a  distance,  it  would  be  necessary  to  reduce  the  size  of  its 
opening  Fig.  ~>17)  to  that  embraced  at  the  level,  /)'-//,  between  the 
dotted  lines  passing  through  X,  and  marking  the  limit  of  the  opening 
in  the  contact  diaphragm.  The  opening  in  the  diaphragm, ///)'  '  Figs. 
")17  and  .">lSi.  may  be  the  opening  in  a  plane  diaphragm  or  the  proxi- 
mal opening  in  a  conic  or  in  a  cylindric  one.  The  best  effect  with  the 


802 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


latter,   of  course,   is  obtained  when  the  proximal  opening  is  reduced  by 
a  plane  diaphragm  so  as  to  really  secure  the  benefit  of  a  conic  shape. 

It  seems  from  the  foregoing  that  the  diaphragm  applied  directly 
to  the  wall  of  the  tube  enables  us  to  secure  a  wider  field  with  equal 
definition.  In  actual  practice  a  3-inch  diaphragm  allows  the  radiograph 
to  cover  the  whole  of  a  1  1  X  17-inch  photographic  plate,  'J2  inches  from 
the  anticathode,  and  shows  both  kidneys,  ureters,  the  bladder,  and  pros- 
tate; and  a  1-inch  diaphragm  embraces  the  entire  pneumatic  sinus  area 


Fig.   ~>17. — T)-D.  Tousry's   contact   dia-  FIL'.  .",1s. — Large  opening   and   greater 

i  :  .:-.-:Lr::: :  smaller  opening  and  much  less  amount  of  blurring  with  ordinary  dia- 
Nurring  than  with  ordinary  diaphragm  phragm  giving  same  area  of  illumination 
//-//.  as  \\itli  Tousry's  contact  diaphragm  (.com- 

pare   Fig.  .-,17). 

nf  the  face.  The-  hitter  may  be  excellently  observed  in  the  fluoroscope, 
if  the  operator  cares  to  run  the  risk  of  injury,  and  a  radiograph  is  easily 
made  after  centering  the  rays  under  actual  observation.  A  11-inch 
diaphragm  gives  sufficiently  good  definition,  and  as  it  takes  in  the  entire 
face  the  fluoroscope  need  not  be  used  in  centering  the  ravs. 

A'-ray-proof    Aprons,    Gloves,    and    Spectacles. — Sheet     rubber 

containing  baryta  or  lead  oxid   may  be   made  as  opaque  as  desired  to 

the  ./--ray.      It  may  be  cut  into  aprons  or  gloves  to  protect  the  operator. 

or  into  appropriate  sixes  and  shapes  to  limit   the  field  of  exposure  in 

a  j  iy. 

Spectacles  of  flint  gla-s  containing  a  large  percentage  of  lead  are  a 
valuable  protection  for  the  operator's  eyes  in  fiuoroseopic  work.  It 
must  1  ii  remembered,  also,  thai  even  the  reduced  fraction  of  the  radiation 
which  will  pass  through  the  entire  thickness  oi  the  patient's  body  is 
in jurioii.-  to  the  operator,  who  is  often  exposed  to  it. 

A  sheet  of  lead  glass  covering  the  barium-plat inocyanid  surface  oi 
a  fliioroscent  screen  enables  one  to  see  the  image  perfectly  well  while 
it  protect.-  the  operator's  face  from  the  rays. 

A'-ray-proof  Gloves.1 — Soak  thick  leather  gloves  in  a  saturated 
solution  of  bismuth  chlond,  ihen  immerse  them  in  cold  running  water 
fur  an  hour,  drv  them  thoroughly,  and  repeal  the  process  two  or  three 
times.  An  interstitial  deposit  of  o.xychlorid  of  bismuth  is  formed. 

Material  for  A'-Ray-proof  Garments. — An  improved  material 
h;;-  ::.-'  In  en  imported  into  this  country.  It  consists  of  two  sheets  of 
strong  cotton  cloth  between  which  is  a  thick  layer  of  rubber  containing 
:  I  Jr.  Win.  Mitchell.  Arch,  of  Kontjr.-n  Kay,  April,  I'.lOv 


THE    X-KAY  803 

a  certain  percentage  of  lead.  It  is  much  more  durable  than  the  mate- 
rials previously  in  use.  The  outer  surfaces  are  sufficiently  coated  with 
the  same  rubber  composition  to  be  water-proof. 

Xafcti/  to  the  operator  requires  that  he  shall  be  in  an  rc-ray-proof 
cabinet  covered  on  all  sides  and  top  with  sheet  lead  or  x-ray  metal,  an 
alloy  of  lead  and  tin  which  remains  bright  and  does  not  rub  off  on  hands 
or  clothing.  The  metal  should  be  /,-.  or  ^  inch,  depending  upon  how  near 
the  .r-ray  tube  is  going  to  be.  The  necessary  windows  are  of  very  heavy 
lead  glass  transparent  to  light,  but  opaque  to  the  .r-ray.  All  the  meters 
and  switches  should  be  inside  the  cabinet.  If  no  cabinet  is  practicable 
the  operator  should  be  behind  a  brick  wall  or  a  lead-covered  partition 
extending  across  the  entire  height  and  width  of  the  room.  With  these 
precautions  he  can  dispense  with  .r-ray-proof  clothing. 

The  Fluoroscope. — A  fluoroseopic  screen  is  usually  a  sheet  of 
card-board  coated  on  one  side  with  barium-platinoeyanid,  a  chemical 
which  becomes  brightly  fluorescent  when  exposed  to  the  .r-ray.  Tung- 
state  of  calcium  can  be  used  in  the  same  way.  The  hitter  gives  a  white 
and  the  former  a  greenish  light.  In  a  dark  room  the  patient  stands 
between  the  observer  and  the  .r-ray  tube,  and  the  screen  is  held  close 
to  the  patient  with  its  chemically  coated  surface  toward  the  observer. 
Wit  h  t  he  proper  amount  of  radiance  a  pict  ure  is  seen  upon  the  fluorescent 
surface  of  the  screen,  which  is  really  a  shadow-picture,  representing  the 
different  densities  of  the  parts  under  observation.  For  most  purposes 
it  is  more  convenient  to  have  the  screen  form  the  end  of  a  dark  box, 
which  enables  us  to  use  the  screen  without  darkening  the  room. 

The  accessory  apparatus  and  the  details  of  technic  are  considered 
in  the  chapters  on  Radiography,  Fluoroscopy,  and  Radiotherapy. 

A  Home-made  Calcium- tungstate  Screen. — The  materials  required 
are  1  ox.  sodium  chlorid,  1  ox.  sodium  tungstate,  and  t  ox.  calcium  chlo- 
rid.  Powder  these  together  and  put  them  in  a  crucible  with  a  tin  cover 
and  set  right  in  a  fire  with  glowing  coals  heaped  around  it  for  two  or 
three  hours.  The  compound  is  converted  into  a  clear  liquid  which  crys- 
talli/es  into  a  glass-like  mass  on  cooling.  Break  this  up  into  a  coarse 
powder,  put  it  in  water,  which  will  dissolve  out  the  sodium  chlorid.  and 
fine  crystals  of  calcium  tungstate  will  settle  to  the  bottom.  Pour  off 
the  water,  add  more  water,  and  decant.  Do  this  several  times  until 
all  taste  of  salt  disappears.  This  part  of  the  process  takes  twenty-four 
hours.  Pour  the  sediment  on  a  sheet  of  blotting-paper  and  dry  in  the 
sunlight.  Coat  a  piece  of  tracing  paper  or  linen  cloth  with  flexible 
collodion  oi'  glue  and  sprinkle  the  fine,  dry  crystalline  powder  over  it. 
Repeat  the  coating  with  collodion  or  glue  and  the  sprinkling  with 
calcium-tungstatc  crystals  two  or  three  times.  (The  total  cost  of  the 
materials  including  the  crucible  is  only  about  20  cents.  1  (Kolle, 
"  A'- rays.") 

Intensifying  Screens. — If  a  photographic  plate  is  enclosed  in  the 
same  cassette,  or  entirely  enclosed  plate-holder,  with  a  means  of  press- 
ing the  two  chemic  surfaces  close  together,  exposure  to  the  .r-ray  will 
produce  a  double  effect.  First,  there  will  be  the  image  produced  upon 
the  photographic  plate  by  the  .r-ray  and.  second,  the  image  produced 
upon  the  plate  by  the  bright  fluorescent  light  which  occurs  on  the 
screen.  With  the  modern  intensifying  screen,  the  latter  effect  is  three 
times  as  great  and  completely  overshadows  the  direct  .r-ray  effect. 
There  are  some  advantages  connected  with  the  tungstate  of  calcium 


804  MEDICAL    KLKCTKICITY    AND    H(")NT(iEN     HAYS 

screen  for  intensifying,  because  it  give's  a  whiter  light  than  the  barium 
platinocyanid  screen,  which  is  more  generally  used  for  fiuoroscopic 
examinations. 

Intensifying  screens  greatly  shorten  the  time  of  exposure.  The 
best  ones,  like  those  made  by  Dr.  Threlkeld-Kdwards.  of  South  Bethle- 
hem, IVnna.,  I.  S.,  or  made  by  Patterson  reduce  the  time  to  one-third  of 
the  ordinary  exposure.  With  the  increase  in  speed  there  is  some  loss  of 
details,  as,  for  instance,  in  the1  structure  of  the  bones.  As  a  consequence, 
it  would  not  be  desirable1  to  use  an  intensifying  screen  for  making  a  radio- 
graph of  the  hand.  Even  with  a  weak,  portable  x-ray  outfit,  it  is  practi- 
cable to  obtain  a  direct  radiograph  of  the  hand  without  an  excessive 
exposure.  It  is  a  different  matter,  however,  when  the  thigh  or  body  of  a 
large  person  must  be  radiographed  with  a  portable  outfit,  and  also  when 
a  number  of  radiographs  must  be  made  through  the  body,  as  for  an  ex- 
amination of  the  shape  and  position  of  the  stomach  and  intestines,  after 
a  bismuth  meal  or  enema,  even  with  the  most  powerful  apparatus.  In 
these  cases  safety  to  the  patient  and  convenience1  and  economy  of  wear 
and  tear  upon  apparatus,  and  the  desirability  of  snapshots  of  moving 
parts,  e-dl  for  the1  employment  of  an  intensifying  screen.  A  good  intensi- 
fying screen  has  become  an  essential  part  of  the-  equipment  of  a  Rontgen- 
ray  laboratory. 

The  best  screens  are'  exceedingly  fine1  grained,  and  show  very  little 
of  the  structure  eif  the  screen  upon  the1  photographic  plate  if  the  ex- 
posure and  development  have  been  right. 

7'<N//w/  S  peed  of  Intensifying  Screcnx. — One  way  with  the1  screen  be- 
yond the  film  is  to  interpose  black  paper  between  one  half  of  the  film 
and  the  screen  and  then  to  give  different  sections  of  each  half  various- 
exposures  and  develop  the  entire1  film  at  once1.  But  there's  the1  rub. 
The  screen  effect  is  mostly  on  the1  surface1  and  develops  quicker,  and 
according  to  the  time1  of  development,  that  part  may  turn  out  from 
five  to  only  two  times  the  elensity  of  the  part  not  affecteel  by  the  screen. 
I'-insi  such  exposure's  and  such  a  strength  of  developer  that  the1  film 
take-  ten  minutes  in  complete  darkness  to  attain  its  maximum  density 
a  very  good  test.  The  comparison  should  state'  that  equal 
-ult-  from  an  exposure  so  many  times  shorter  with  the  screen; 
the  same  length  of  exposure  produces  so  many  time's  the1 
The  speed  determined  in  this  way  is  merely  a  guide  to  the 
practical  1e-t  of  finding  the  best  expo.-ure  of  the  same'  subject  with  a 
-creen  and  the  best  \\ithout  a  screen:  not  necessarily  giving  the1  two 
-ame  exposure,  but  giving  each  the  development  best  suited 
['hi-  practical  test  will  tell  us  how  much  longer  exposure  it  is 
to  u'i\v  without  than  with  a  certain  intensifying  screen, 
pi-ed  of  a  -ingle  screen  in  front  of  the  plate  is  not  correctly 
-  merely  tnterpo-ing  black  paper,  because  both  parts  of  the 
deprived  of  a  great  deal  of  the  original  .r-ray  by  the  screen, 
have  a  plate  lamer  t  lian  1  he  -creen,  so  t  hat  one  part 
strengthening  from  the  screen  but  also  is  not  weak- 


.r-ray  lilm-  offer  the  temptation  to  place  a  screen  in 
behind,  and  a  te-t  ha-  been  reported  in  which  this 

tive  a-  a  single  screen  behind.  But  Dr.  Threlkeld- 
nvinced  by  hi-  experiment-  that  the  screen  in  front  usually 
uch  a-  it  add-.  The  only  way  to  te-t  the  speed  with  two 


THK    .T-KAY  S().r) 

screens  is  to  have  a  part  of  the  film  entirely  beyond  the  edge  of  the  front 
screen,  not  covered  by  it,  and  shielded  by  black  paper  from  the  back 
screen.  The  speed  with  two  screens  has  seemed  to  the  author  to  be  the 
same  as  with  one  screen  of  the  same  quality  behind  the  film. 

Two  intensifying  screens  could  not  be  used  with  a  plate  because 
the  thickness  of  the  glass  between  the  screen  and  the  sensitized  coating 
would  blur  the  image. 

Ditpliti'zed  Film  irith  Tiro  Intenttifi/ing  Screens. — Two  intensifying 
screens  of  the  Edwards  make,  one  heavily  coated  beyond,  and  one 
lightly  coated  in  front  of  the  film,  have  been  tried  by  the  author  with 
a  duplitized  film  between  them  and  compared  with  a  duplitized  film 
with  only  one  heavily  coated  Edwards'  screen  beyond  it.  The  subject 
was  the  chest  (measuring  34  inches;  of  a  girl  weighing  120  pounds, 
and  the  films  were  developed  for  the.  same  length  of  time.  The 
exposures  had  been  the  same  and  the  finished  films  could  not  be 
told  apart.  Dr.  Threlkeld-Edwards  believes  firmly  that  all  that  can 
be  gotten  out  of  intensifying  screens  and  films  coated  on  both  sides  is 
obtained  by  using  the  heaviest  coating  on  the  screen  beyond  the  film 
and  that  the  screen  proximal  to  the  film  detracts  as  much  by  the  opacity 
of  its  barium  platinocyanid  as  it  adds  by  its  fluorescence. 

An  experiment  by  the  author  consisted  in  covering  the  south  half 
of  the  Edwards  screen  with  black  paper  so  that  only  the  north  half  of  a 
duplitixed  film  laid  upon  it  was  exposed  to  its  radiance.  Black  paper 
was  laid  over  the  west  half  of  the  upper  surface  of  the  film  so  that  while 
the  whole  film  suffered  the  partial  obstruction  of  .r-ray  by  the  thin 
Patterson  screen  laid  over  it,  only  the  east  half  received  the  radiance 
from  the  latter.  The  northeast  corner  received  the  radiance  from 
both  films  and  the  southwest  from  neither,  and  the  southeast  from 
the  Patterson  screen  alone  and  the  northeast  corner  from  the  Edwards 
screen  alone.  The  .r-ray  tube  was  above,  so  that  the  .r-ray  shone 
through  the  Patterson  screen  over  the  entire  duplitized  film  to  the 
Edwards  screen.  A  very  slight  .r-ray  exposure  was  made.  In  develop- 
ment the  surface  that  had  been  toward  the  Patterson  screen  came  up 
with  the  east  half  black  and  the  west  white:  while  the  other  surface 
showed  the  north  half  black  and  the  south  white.  Later,  after  fixing, 
washing,  and  drying,  the  film  was  viewed  by  1  ransmitted  light  and  showed 
the  parts  shielded  from  both  screens  very  thin.  The  parts  exposed  to 
the  radiance  from  the  Edwards  screen  alone  and  the  Patterson  screen 
alone  were  of  about  the  same  density,  which  was  about  equal  to  the 
density  of  a  separate  single-coated  film  exposed  to  the  radiance  of  the 
Ed\vards  screen  without  the  obstruction  of  the  Patterson  screen,  and 
were  only  half  as  dense  as  a  separate  double-coated  film  exposed  like 
the  single-coated  film  just  described.  The  part  of  the  duplitixed  film 
receiving  the  radiance  from  both  the  Patterson  and  the  Edwards 
screen  was  about  twice  as  dense  as  parts  affected  by  radiance  from 
eit  her  screen  separately,  but  weakened  by  the  opacity  of  the  front  screen; 
not  quite  as  dense  as  a  separate  duplitixed  film  exposed  to  the  radiance 
of  the  Edwards  screen  alone,  but  without  the  obstruction  of  the  Pat- 
terson screen. 

There   seems   to    be  some  fallacy   in 
preceding   paragraphs,   for  other  tests 
double   screen   technic  is   about    twice   a- 
author  employ-  it  for  all  abdominal  and  most  head  radiograph- 


MKDICAL    KLKCTHICITV    AM)    UONTCKN    KAYS 

The  author  cannot  corroborate  Dr.  Threlkeld-Edwards'  opinion  that 
two  screens  are  no  faster  than  one  beyond  the  film,  and  that  the  greatest 
speed  is  obtained  with  the  fastest  (according  to  Edwards  this  means 
the  heaviest  coated1  single  screen  beyond  the  film. 

Sliijfit  Loxx  of  Diltiil  in'th  Intensifying  ^crcen* — Author*  Text. — 
The  presence  of  grain  in  a  radiograph  made  with  a  single  screen  placed 
beyond  the  plate  or  film  shows  that  some  detail  has  probably  been  lost 
in  the  object  depicted.  The  absence  of  grain  in  a  radiograph  made 
upon  a  double-coated  film  between  two  intensifying  screens  makes  a 
nice  It. Miking  picture,  but  it  does  not  mean  that  no  detail  has  been  lost. 
Quite  the  contrary  is  the  case.  Each  screen  has  obscured  details  called 
grain  due  to  the  other,  and  each  has  obscured  details  of  the  object. 
The  author's  test  of  this  is  to  make  radiographs  of  wire  netting,  Lionel 
metal.  -4s  meshes  to  the  linear  inch,  Eastman  dupliti/ed  .r-ray  film, 
partly  without  any  intensifying  screen,  partly  with  a  screen  behind, 
partly  with  a  screen  in  front,  and  partly  with  screens  both  front  and 
back.  If  the  last  named  exposure  is  one-quarter  second,  the  others 
would  vary  up  to  one  and  a  half  seconds  without  any  screen  in  order  to 
secure  uniformity  of  exposure.  Of  course  care  must  betaken  that  the 
screen  or  screens  are  pressed  in  close  contact  with  the  film.  The  result 
will  be  a  beautifully  dear  image  of  the  wire  netting  with  microscopic 
detail  when  no  screen  is  used,  and  progressive  though  very  slight  loss 
of  detail  when  screens  are  used  in  the  order  named  above.  In  every  ease 
the  detail-  are  clearly  visible. 

\\'ln  n  lo  ['.-</  Inti-naifijiiKj  Scret  n*  and  \\'hen  \ot  to. —  The  only  reason 
for  u-ing  an  intensifying  screen  i.-  to  secure  a  picture  with  a  shorter  ex- 
po-ure  than  the  same  factors  would  require  without  a  screen.  This  is 
operative  in  the  case  of  objects  movable  or  liable  to  move  and  in  the 
ea.-e  of  objects  of  Mich  thickness  or  density  that  the  exposure  borders 
upon  the  undesirable1.  It  is  also  operative  in  case-  where  such  a  number 
of  expo-ure-  of  the  same  part  of  the  body  are  nece-.-ary  that  the  total 
expo-lire  borders  upon  the  undesirable.  In  all  these  cases  the  slight 
loss  of  detail  i-  disregarded.  It  is  also  operative  in  cases  where  sufficient 
mly  obtainable  with  a  very  short  .-park  equivalent  and  the 
i-ure  i-  greatly  increased. 

or  more  of  the  above  rea.-ons  the  author  uses  an  intensi- 
for  practically  all  gastrointestinal  radiographs,  all  antero- 
•rior  he;id  radiographs,  kidney,  gall-bladder,  -pine,  and  pelvis 
>iLTaphs  in  stout  subjects,  and  most  pictures  of  small  children, 
"he  only  reasons  for  not  always  using  an  intensifying;  screen  are 
act  of  -liidit  loss  of  detail  and  also  the  presence  of  grain  with  a 
e  screen,  the  matter  of  convenience,  and  the  matter  of  lag.  Bone 
.  in  general  and  lung  radiographs  show  better  details  of  structure 
are  u-ually  done  without  a  screen  unles-  there  are  special  reason-; 
to  the  contrary.  (  onveniencc  of  manipulation  i-  sometimes  in  favor 
of  the  screen.  Thi-  i-  mounted  in  a  cassette,  which  i-  the  most  conve- 
nient kind  of  a  plat  e-holder,  and  to  a  void  t  he  etiect  of  i  he  screen  we  have 
a  piece  of  bhick  paper  over  the  latter.  Either  with  or  without 
the  effect  of  the  screen  the  cassette-  is  very  much  more  convenient  than 
black  and  orange  envelope-.  Y\ith  film.-,  however,  such  convenient 
holder-  ;ire  available  'page  MO  that  while  t  he  cassel  te  i-  indispensable 
for  -creen  work,  it  has  no  ureat  advantage  when  the  black  paper  must 


THI-:  X-HAY  807 

without  an  adjacent  dark-room  in  which  to  change  the  plates  or  films 
it  may  he  very  much  more  convenient  to  have  the  latter  in  separate 
envelopes.  A  considerable  number  of  screens  would  accomplish  tin1 
purpose,  but  are  not  always  available  and  are  very  heavy. 

The  Latj  of  Intensifying  Novr//*. — This  is  the  persistence  of  radiance 
capable  of  affecting  a  photographic  plale  after  the  .r-ray  has  been  turned 
off.  After  making  any  radiograph  in  which  part  of  the  screen  is  ex- 
posed without  the  interposition  of  the  patient  that  part  is  found  to  be 
brilliantly  luminous  if  the  cassette  is  immediately  opened  in  the  dark- 
room. And  a  complete  silhouette  of  the  part  depicted  may  be  seen  upon 
the  screen.  This  would  suggest  the  possibility  of  the  picture  becoming 
stronger  if  the  plate  wore  left  in  contact  with  the  screen  until  the  lumi- 
nosity had  disappeared  and  the  possibility  of  the  plate  being  fogged  as 
it  is  removed  from  the  cassette,  and  also  possibility  of  a  new  plate  put  in 
contact  with  the  screen  receiving  an  image  which  would  blur  the  suc- 
ceeding picture.  Intensifying  screens  vary  in  regard  to  lag.  In  an 
experiment  by  the  author  a  lightly  coated  intensifying  screen  in  a 
ca-^ette  was  exposed  to  .r-ray,  o-inch  spark,  30  ma.  ten  seconds  at  23 
inche<.  A  minute  later  the  cassette  was  opened  and  an  East  men 
dupliti/ed  .r-ray  film  was  partly  in  direct  contact  with  the  screen  and 
partly  protected  by  a  piece  of  black  paper.  After  two  minutes'  con- 
tact the  film  was  fully  developed  and  showed  no  trace  of  exposure. 
In  spite  of  the  brilliant  luminosity  there  was  no  lag,  and  another  picture 
could  have  been  made  without  waiting  for  the  light  to  have  faded 
out. 

In  a  similar  experiment  with  another  make  of  screen  the  film  was 
fully  blackened  except  for  a  transparent  image  where  a  lead  letter  had 
been  laid  over  the  cassette  while  the  .r-ray  had  been  turned  on.  This 
screen  had  very  marked  lay;,  although  its  persistence  of  luminosity  was 
no  different  from  that  of  the  other  screen  which  had  no  demonstrable 
lag. 

Visible  luminosity  in  the  part  which  had  been  covered  by  the  patient's 
body  indicates  overexposure.  It  is  only  in  the  part  of  the  screen  un- 
covered in  the  first  picture  but  perhaps  forming  part  of  the  image  in 
the  succeeding  radiograph  that  lag  would  be  apt  to  be  a  disturbing 
factor. 

A  lagless  screen  may,  of  course,  be  used  for  several  pictures  in  more 
rapid  succession  than  one  with  marked  lag.  With  the  latter  several 
screen-  are  necessary  when  pictures  are  to  be  made  in  rapid  succession. 

The  choice  of  the  plate  for  screen  work  is  important.  One  like  the 
Imperial  .r-ray  plate,  with  a  thin  sensitized  coating,  gives  better  results 
for  this  purpose  than  the  thicker  coated  Ilford  .r-ray  plates,  which  are 
so  much  better  for  direct  radiography. 

In  making  the  exposure  the  glass  side  of  the  plate  should  be  toward 
the  .r-ray  tube  and  the  sensiii/ed  surface  toward  the  intensifying  screen. 

For  the  best  detail  the  exposure  should  be  such  that  the  plate  will 
show  the  proper  density  after  fifteen  to  thirty  minutes'  development  with 
the  Threlkeld-Edwards  developer.  More  commonly  a  stronger  exposure 
i>  given  which  requires  only  three  or  four  minute's'  development. 

An  over-exposure  causes  the  image  to  flash  up  so  quickly  that  the 
plate  is  fully  developed  in  about  two  minutes,  and  shows  every  grain 
of  the  intensifying  screen.  It  is  evidenced  at  once  by  the  appearance 
of  the  intensifying  screen  when  the  plate  is  removed  in  the  dark  room. 


s'  MKDICAL    KLK(  THICITY    AND    H(")\T(iKN     HAYS 

Hie  portion  of  the  screen  covered  by  the  thicker  parts  of  the  patient 
should  not  show  a  bright  persistent  fluorescence. 

Thri'lkcld-Edwards  Developer  for  Screen  Plates. 

Water  (distilled) 4S  ounces. 

Sodium  sulphite  ulry) 2  ounces. 

Hydroquinone ">  drains. 

Kikonogen i  drain. 

Potassium  carbonate  (dry) 4}  ounces. 

Potassium  broinid  (25  per  cent,  solution) f>  drams. 

(One  dram  equals  4.0  grammes,  and  1  ounce  equals  '.^'2  grammes.) 

The  loss  of  definition  in  consequence  of  the  granular  character  of  the 
fluorescent  surface  is  not  deceptive  in  any  way,  and  a  reduced  copy  of  a 
picture  made  in  this  way  does  not  show  the  granular  appearance. 
Radiography  of  the  chest  is  a  case  in  which  very  short  exposures  are 
likely  to  be  more  useful  than  those  of  medium  duration.  Even  here 
the  discovery  of  commencing  consolidation  is  better  made  without  an 
intensifying  screen,  seeking  the  element  of  speed  in  a  brilliant  radiance 
and  a  sensitive  plate,  and  having  the  patient  hold  his  breath  during  the 
exposure.  This,  however,  is  also  one'  of  the  cases  in  which  a  fluoroscopic 
examination  would  have  advantages  over  the  radiograph  except  for  its 
danger. 

The  different  factors  have  been  considered  at  length  because  of 
the  assistance  this  may  afford  to  others.  To  learn  the  successful  and 
safe  use  of  the  .r-ray  one  must  try  to  profit  by  the  hundreds  of  hours 
spent  by  others  in  study  and  experiment,  and  must  also  expend  a 
similar  amount  of  time,  money,  and  labor  in  practical  work  with  the 
apparatus. 

THE  SENSITIVENESS  OF  THE  FILM.   PLATE.   OR  PAPER 

The  dry  plates  sold  by  the  various  manufacturers  of  photographic 
supplies  under  the  name  of  .r-ray  plates  have  about  the  best  degree  of 
>ensit  iveness  and  are  often  made  with  a  double  or  triple  coating.  The 
latter  gives  density  to  the  picture,  adds  .-lightly  to  the  speed  of  the 
plate,  but  adds  very  greatly  to  the  time  and  care  required  for  develop- 
ment. For  some  reasons  it  seems  best ,  under  cert  ain  conditions,  to  use 
the  most  rapid  regular  daylight  plates,  of  which  the  Cramer  Crown 
plate  may  be  mentioned  as  an  example.  The  daylight  plates  are  in 
use  in  l;iri:e  numbers  everywhere  and  hence  may  be  more  easily  secured 
m  a  fre-h  condition  than  the  special  .r-ray  plates.  The  kodak  film 
produce-  ;tn  excellent  .r-rav  picture,  but  according  to  mv  own  observa- 
tion-; i-'  about  one-third  as  rapid  as  the  Cramer  (Town  plates.  A 
-eric-  df  experiment-  has  been  made  by  the  author  to  determine  the 
relative  -peed  of  the  .r-ray  and  gaslight.  It  was  found  that  gaslight 
\v;t-  m;iny  time-  more  rapid  than  the  .r-ray.  The  comparison  was  made 
between  a  o-foot  gas-burner  at  a  di-taiice  of  .">  feet  and  a  heavy  target 
Miiller  tube  with  ;i  resistance  of  2',  inches,  1 2-inch  coil  with  large  self- 
inductance:  ('aldwell  interrupter,  (.>  amperes  no  rheostat  resistance: 
.'Hi'l  (  miner  .r-ray  plate  in  black  and  orange  envelopes,  11  inches  from 
il  ode,  ditterent  part-  exposed  fifteen,  thirtv,  sixtv.  and  one  hun- 
dred  and  twenty  seconds.  The  portion  of  a  similar  plate  which  was 
exposed  to  ga-lighl  for  forty  second-  was  as  dense  as  that  exposed  to 
the  .r-ray  for  three  time-  a-  King.  I'oth  plate-  were  developed  in 
exactly  the  -ame  wav  and  for  the  ,-ame  length  of  time.  It  will  be 


THE    X-RAY  809 

soon  that  the  photochemic  offoot  of  the  x-ray  from  a  tubo  giving  a 
brilliant  radiance  is  only  ono-third  as  groat  as  that  of  a  small  gas-jot 
at  five  times  the  distance.  Taking  the  relative  distances  into  account, 
the  difference  in  power  is  about  7-J  to  1  in  favor  of  the  ga.slight.  Sunlight, 
of  course,  is  incomparably  more  effective  than  the  x-ray,  photograph- 
ically. The  wonderful  thing  about  the  x-ray  is  not  the  amount  of 
effect  it  has  on  a  photographic  plate,  but  that  its  effect  is  produced 
even  after  passage  through  great  thicknesses  of  animal  tissues  and  other 
opaque  substances. 

The  Lumiere  Sigma  plates  and  films  are  four  times  as  rapid  as  the 
fastest  made  in  America  and  are  excellent  for  x-ray  work.  Sehleussner's 
x-ray  plates  arc  also  good,  but  not  as  fast. 

The  sensitiveness  of  regular  brornid  paper  is  about  one-fifth  that  of 
a  regular  plate.  This  makes  it  suitable  only  for  the  extremities  and  the 
teeth.  To  make  a  good  picture  of  any  portion  of  the  trunk  upon  this 
paper  would  require  a  dangerously  long  exposure.  Wo  sometimes  use 
one  or  more  pieces  of  bromid  paper  exposed  at  the  same  time  as  the 
film  or  plate  for  pictures  of  the  teeth,  hands,  or  feet.  It  enables  us 
to  got  an  immediate  picture,  not  so  good  as  it  would  bo  if  we  were  to 
give  it  the  longer  exposure  which  the  paper  really  requires,  but  which 
is  useful  as  a  proof.  It  shows  whether  the  position  has  been  a  successful 
one  or  not.  The  bromid  paper  alone  is  splendid  for  cases  in  which  an 
x-ray  diagnosis,  is  required  immediately,  as  for  the  removal  of  a  foreign 
body  or  the  treatment  of  an  obscure  injury.  The  picture  may  be  devel- 
oped at  once  without  a  dark-room,  but  in  a  faint  light,  and  is  made 
upon  the  same  identical  piece  of  paper  which  is  exposed  to  the  x-ray. 
This  exposure  is  a  very  great  deal  shorter  than  is  required  for  a  fluoro- 
seopio  examination  in  a  case  of  any  difficulty  and  prevents  the  possibility 
of  a  burn,  either  of  the  patient  or  the  physician,  and  it  will  frequently 
show  a  needle  or  splinter  which  cannot  be  detected  by  the  fluoroseope. 
Inconsequence,  perhaps,  of  an  article  of  mine  upon  this  method1  its  use 
has  become  generally  known,  and  in  several  instances  physicians  have 
written  me  of  its  successful  application  in  cases  where  the  fluoroseope  had 
tailed  and  where  the  necessary  apparatus  and  tochnic  for  developing  a 
plate  were  wanting. 

Ivdntgen  paper  is  now  made  as  sensitive  as  tho  usual  x-ray  plate 
and  suitable  for  all  kinds  of  radiography.  It  is  a  bromid  paper,  but 
requires  to  be  developed  by  ruby  light. 

The  loss  sensitive  photographic  plates  are  entirely  unsuitod  to 
general  radiography.  An  exposure  which  will  produce  a  good  picture 
on  the  right  kind  of  plate  will  often  not  show  a  trace  of  structure  upon 
one  of  the  less  sensitive  plates.  There  are  many  different  degrees  of 
sensitiveness  in  the  plates  made  by  the  same  manufacturer.  Some  are 
intended  for  one  purpose  and  some  for  another,  but  when  it  is  considered 
that  the  x-ray  is  only  about  ono~soventy-fifth  as  rapid  as  a  moderate 
gaslight,  it  will  readily  be  seen  that  only  plates  of  the  highest  sensitive- 
ness are  suitable.  To  produce  a  good  picture  through  any  thick  portion 
of  the  body  upon  one  of  the  less  sensitive  plates  would  require  a  dan- 
gerous exposure  to  the  x-rav. 

Halation  in  photography  is  supposed  to  be  the  result  of  a  reflection 
of  liiiht  back  from  the  further  surface  of  the  plate.  Its  effect  becomes 

Medical  .Journal.  August 


S10  MEDICAL    KLI-XTRICITY    AND    KOXTUKX    RAYS 

apparent   when  a  photograph  is  taken  of  a  very  brightly  illuminated 

object  \vitli  sharp  outlines.  Such  a  picture  might  be  taken  with  the 
camera  pointed  toward  a  window  with  small  panes  and  with  bright 
daylight  outside.  Instead  of  what  we  are  accustomed  to  speak  of  as 
photographic  sharpness,  we  would  obtain  a  picture  showing  blurred 
outlines  of  the  cross-bars  separating  the  panes,  as  if  the  effect  of  the 
brilliant  light  of  the  panes  had  extended  partly  to  the  dark  portion 
of  the  plate  upon  which  the  image  of  the  cross-bars  is  impressed. 
Yariou-  remedies  have  been  tried  to  prevent  this  reflection,  and  what 
are  known  as  non-halation  plates  are  considered  the  best.  In  effect 
the.»e  are  plate.-  with  a  double  thickness  of  film,  so  thai  almost  all  the 
light  i>  arrested,  and  the  resulting  image  is  so  dense  that  the  slight 
reflection  which  may  still  be  present  does  not  show  upon  the  picture. 
All  the  celluloid  films  are  almost  free  from  halation.  Experiment  ing  as 
to  halation  the  author  has  made  radiographs  of  sharply  defined  metallic 
objects,  such  as  coin.-  and  needle-,  placed  practically  in  contact  with  the 
plate  and  with,  the  ./'-ray  falling  in  some  cases  vertically,  and  in  others 
at  various  angles,  up  to  the  greatest  angle  ever  required  in  practice. 
In  the  entire  series  of  experiments  there  was  no  effect  of  the  nature  of 
halation  produced.  A  lead  marker  in  the  middle  of  the  image,  for  in- 
stance, at  the  umbilicus,  shows  perfectly  clearly,  while  one  near  the  edge 
of  the  image  shows  a  blurred  shadow.  This  is  due  not  to  halation,  but 
to  secondary  rays  from  the  tissues,  more  from  one  direction  than  another. 
The  purpose  of  having  the  objects  as  near  as  possible  to  the  plate  is  to 
eliminate  the  aberration  which  inevitably  occurs  in  the  image  of  an  ob- 
ject at  any  distance  from  the  plate  and  which  has  no  relation  at  all  to  the 
special  condition  produced  by  a  diffuse1  reflection  from  the  back  of  the 
plate.  My  experiments  have  led  to  the  conclusion  that  halation  is  not 
a  disturbing  factor  in  radiography,  and  that  celluloid  films  or  double- 
or  triple-coated  plates  are  not  required  on  this  particular  account 
except  with  an  intensifying  screen.  ( 'elluloid  films,  coated  on  both 
sides  with  an  especially  sensitive  emulsion,  are  made  by  some  of  the 
manufacturers,  expecially  in  Kurope,  for  instantaneous  radiography 
of  the  chest,  and  an1  intended  to  be  used  between  two  intensifying 
screens. 

The  Kastman  dupliti/ed  .r-ray  film  is  coated  on  both  sides  with  an 
emulsion  which  give-  it  the  same  speed  as  the  Seed  .r-ray  plate.  It 
can  t>e  u-ed  without  a  -creen  or  with  either  one  or  two  screens. 

(  >ne  very  great  mlriin/d'jr  nf  jUni*  is  that  they  cannot  be  broken  either 
by  the  weight  of  the  patient  or  during  previous  or  subsequent  handling. 
//, j!« i// i/niin'H/i/  i if  ('<  llnluiil  /-'.'7///N.  A  factor  which  must  be  taken 
account  i-  the  inflammability  of  films,  which  has  led  to  such  fatal 

ident^  in  moving  picture  theatres.  Stringent  laws  require  the 
motion  picture  film-  to  be  enclosed  in  fire-proof  boxes  when  carried  on 
trains  or  when  in  any  building.  One  might  -upjxise  that  the  heavy 
r  deposit  on  both  -ides  of  a  dupliti/ed  film  might  prevent  the  cel- 
d from  catching  fire.  Hut  in  an  experiment  by  the  author,  October 


THE    tf-KAY  81  1 

wrapper  is  simply  folded  over  the  film,  preventing  the  abrasion  marks 
which  would  develop  if  the  film  were  pushed  into  an  envelope.  And 
the  cardboard  prevents  abrasion  marks  in  placing  the  film  under  the 
part  of  the  patient  to  be  depicted.  They  will  hold  one  or  two  films. 

This  would  not  be  suitable  for  use  with  an  intensifying  screen.  The 
latter  requires  a  cassette  in  which  the  film  and  the  screen  are  pressed 
very  firmly  together. 

Artefact*  l']x»i  the  Film. — Abrasion  marks  develop  as  black  lines. 
Another  artefact  develops  wherever  the  film  has  sort  of  crinkled  in 
being  handled.  The  idea  can  be  shown  by  lifting  a  sheet  of  white  paper 
with  the  thumb  over  and  two  finders  under  one  side  or  corner.  The 
paper  may  bend  in  such  a  way  as  to  show  a  distinct  crescent ic  crease 
about  \  inch  from  the  thumb.  Such  a  crease  in  a  film  develops  into 
a  mark  which  might  be  mistaken  for  a  calculus  if  one  were  unfamiliar 
with  its  cause.  Such  an  artefact  is  to  be  avoided  by  holding  the  film 
at  two  opposite  corners  to  prevent  crinkling. 

Relative  Speed  of  Eastman  Duplitized  .r-Raij  Film  and  Seed  x-I\a>j 
JJl<tte.-  In  radiographs  made  by  the  author  in  difficult  subjects,  such  as 
the  kidneys,  a  film  has  been  laid  on  top  of  the  plate,  the  latter  having 
its  sensitized  surface  up  and  the  tube  being  above.  This  has  been  to 
take  advantage  of  any  difference  in  speed  so  as  really  to  have  two  dif- 
ferent degrees  of  effect  made  with  one  exposure  of  the  patient.  The 
idea  was  that  even  the  most  careful  calculation  is  only  approximate,  and 
that  with  two  different  degrees  of  exposure  one  might  be  better  than 
the  other.  The  result,  however,  has  been  that  the  film  and  the  plate 
seemed  just  the  same  while  being  developed  and  also  when  finished. 

The  Duration  of  the  Exposure  with  Induction  Coil  and  Gas-filled 
Tube.-  The  length  of  time  required  to  produce  a  radiograph  is  in- 
fluenced by  the  different  factors  already  discussed.  The  absolute 
safety  of  the  patient  should  be  the  first  consideration,  the  next  con- 
sideration should  be  a  perfect  picture,  and  finally  the  time  of  exposure 
should  be  as  short  as  is  consistent  with  the  first  two  elements  and  with 
economy  of  wear  and  tear  upon  the  apparatus.  (Hher  conditions  being 
the  same,  the  time  of  exposure  is  very  greatly  shortened  by  increasing 
the  strength  of  the  primary  current.  In  some  experiments  of  my  own 
the  result  has  been  that  doubling  the  amperage  of  the  primary  current 
has  reduced  the  time  required  for  a  radiograph  tenfold.  In  the  early 
days  of  tin1  use  of  the  .c-ray  some  operators  adopted  the  plan  of  not 
commencing  to  count  the  time  until  the  anticathode  had  become  red 
hot  "and  the  tube  had  reached  its  maximum  efficiency."  Practically 
ev<Tv  one  of  the  pictures  in  tins  book  was  completed  before  the  anti- 
cathode  became  red  hot,  and  so,  according  to  this  reckoning,  were 
taken  in  less  than  no  time.  In  the  case  of  the  heart,  and  possibly  the 
lungs,  it  is  sometimes  preferable  to  take  a  picture  in  a  very  short  time 
while  ihe  patient  holds  his  breath.  Hy  Using  an  especially  sensitive 
double-coated  celluloid  film  between  two  intensifying  screens  and  a 
primary  current  of  from  20  to  oO  amperes,  such  a  picture  can  be  taken 
in  about  a  second.  On  an  ordinary  .r-ray-plate  and  with  a  current  of 
20  amperes  the  time  for  a  good  picture  would  be  about  twenty  seconds, 
and  with*the  same  conditions  a  picture  of  the  pelvis  \vould  be  made  in 
forty  seconds,  and  of  the  hand  in  one  or  two  seconds,  \arying  the 
conditions  as  to  vacuum  a  little  from  my  standard  as  to  what  produces 
the  best  picture  and  increasing  the  strength  of  the  current,  the  time 


M2  MEDICAL    KI.KCTHIC1TY    AND    H(")NT(;KN    KAYS 

for  a  pelvic  picture  may  easily  be  reduced  to  fifteen  seconds.  The  very 
heavy  currents  required  for  short  exposures  are  a  strain  upon  the  sec- 
ondary coil,  upon  the  interrupter,  and  upon  the  tul>e.  This  is  in  ad- 
dition to  the  less  serious,  hut  none  the  less  annoying,  burning  out  of 
fuses.  Assuming  that  one's  apparatus  is  capable  of  producing  prac- 
tically the  greatest  possible  .r-radiance  with  a  given  strength  of  cur- 
rent, and  that  one  knows  how  to  get  the  best  results  from  it,  the  fol- 
lowing would  be  a  desirable  schedule: 

With  tin  induction-coil: 

Hand  or  teeth .">  to  80  seconds. 

Klbo\v  or  foot 10  to  .")() 

Shoulder,  c-hest,  or  knee  .  .  .  .  1 .">  to  120      " 

IVlvi-;.  head,  vertebra-,  renal  calculi 40  to  200 

The  longer  time  mentioned  under  each  heading  will  suffice  to  make  a  good 
radiograph  with  a  good  coil  and  technic.  but  with  a  moderate  strength  of 
current.  The  shorter  time  given  requires  a  great  deal  more  studv  of  the 
-ubject  and  an  apparatus  which  will  stand  heavy  currents.  Still  shorter 
exposures  may  be  obtained,  either  by  the  sacrifice  of  quality  in  the  radio- 
graph or  increasing  the  size  of  the  coil  and  the  strength  of  the  primary 
current,  about  40  amperes  being  the  limit  of  the  latter.  This  presents 
-till  greater  technical  difficulties  and  increases  the  danger  of  injury  to 
the  tube  or  coil.  In  considering  radiography  of  the  individual  parts  of 
the  body  examples  are  given  which  show  fairly  the  time  required  under 
different  conditions.  Transformers  have  reduced  the  exposures. 

Witli  a  transformer: 

Hand  or  teeth ?,  to  2  seconds. 

Klbow  or  foot 1     to  5 

Shoulder,  chest,  or  elbow l.\  to  7'. 

Pelvis,  head,  vertebra',  renal  calculi 4     to  20 

An  i nti  nxifiii /ifi  xcrccn  reduces  the  above  exposures  to  about  one-t hird. 

The  rays  which  produce  an  effect   on  a  photographic  plate  are  the 

ones  whose  influence  upon  living  tissues  mu.-t    be  taken   into  account. 

With  too  low  a  vacuum  one  might  fail  to  get  a  radiograph  through  the 

lumbar  region,  even  though  the. /'-ray  were  turned  on  long  and  strong 

enough    to    produce    a    severe    burn,    and    the    same    may    be    true   of 

.r-radiance  of  the  riaht   quality  but   from  too  weak  an  apparatus.      In 

either  case  the  little   photochemic  energv   which   does   reach   the   plate 

.'•i   so  -lowly  that  before  the  exposure  \vas  complete  a  dangerous 

effect    would   have  been   produce*  1   upon   the  tissues  of  the  patient.      A 

famous  tnedicolegal  case  was  that  of  a  patient  of  I'rof.   lloffa.  of  Berlin. 

::.    which    case    an    exposure   of    forty-five    minutes    was    required    for   a 

radiograph    of    the    hip-joint,    and    a    burn    resulted.      The    patient    hail 

:<••'  vion-ly    been   exposed   to   the  .r-rav    l>v   some  other   phvsiciaii.      The 

•    ••     '.;:-   dismissed    because   the  exposure    \va-    in    conformity   with    the 

'"--'    technic   available   at    that    time.      Improvements   m   every    part    of 

'  '  •     r-ray  equipment    have  so  much   reduced  I  he  t  ime  of  exposure  as  to 

•    h    possible  to  take  a   irood  picture  of  any  part   of  the  hodv  with 

.'    no    risk    of  any   .-oil    to   the   patient.      This    means   that    the 


TIIK    .T-HAY  Sl!i 

of  the  same  part  at  tho  same  session.  This  is  true  of  the  body,  and 
for  the  teeth  and  hands  several  exposures  may  he  made.  The  element 
of  time  alone  will  not  secure  a  good  picture.  I  have  known  a  man  with 
a  good  N-inch  coil  to  give  an  exposure  of  six  minutes  for  a  kidney-stone 
and  obtain  no  picture,  and  an  exposure  at  another  session  for  sixteen 
minutes  and  find  nothing  on  the  plate.  This  resulted  in  a  severe  burn 
of  the  abdomen.  A  sufficient  time  of  exposure  is  absolutely  necessary, 
but  it  must  be  combined  \vith  correct  details  throughout.  Over- 
exposure  is  undesirable,  but  may  be  corrected  to  some  extent  during 
development,  and  besides,  the  finished  plate  may  if  necessarv  be 
examined  by  a  strong  transmitted  light,  so  that  a  plate  which  would 
be  practically  useless  from  the  standpoint  of  the  daylight  photog- 
rapher may  still  prove  very  good  for  the  diagnosis  and  record  of  the  case. 
The  safe  amount  of  time  during  which  a  patient  may  be  exposed  to  the 
x-ray  is  dependent  upon  the  intensity  of  the  z-radiance  and  slightly 
upon  idiosyncrasy.  At  a  distance  of  9  inches  from  the  anticathode  to  t  he 
surface  of  t  he  body,  and  with  a  tube  of  medium  vacuum  and  an  intensity 
which  permits  the  bones  of  the  li  and  to  be  seen  faintly,  nine  minutes  would 
be  the  maximum  safe  exposure  \vithoutany  previous  experience  with 
the  individual  patient.  Such  an  exposure  might  produce  a  good  picture 
of  an  extremity  or  possibly  of  the  chest,  but  absolutely  nothing  of  the 
pelvis,  and  with  such  radiance  an  exposure  even  twice  as  long  as  would 
be  safe  would  not  result  in  a  picture  of  the  lumbar  region.  The  other 
extreme  would  be  an  .r-radiance  so  powerful  that  a  pelvic  picture  may 
be  made  in  fifteen  seconds  or  less.  There  is.  theoretically,  no  danger 
to  the  patient,  but  practically  it  is  only  in  the  most  expert  hands  that 
success  is  certain  at  the  first  attempt.  The  employment  of  any  such 
powerful  current  is  dangerous  if  the  exposure  is  prolonged,  or  if  the 
exposure  has  to  be  made  repeatedly,  and  this,  of  course,  would  be  the 
case  in  inexperienced  hands.  It  is  very  much  better  To  learn  to  take 
perfect  pictures  with  a  moderate  length  of  exposure,  and  to  consider 
1")  amperes  with  a  110-volt  primary  current  as  the  very  outside  limit, 
until  one  may  fairly  claim  to  know  the '.r-ray  thoroughly  from  personal 
experience.  The  principal  injury  which  may  occur  to  the  tube  trom 
too  strong  a  current  in  the  effort  to  shorten  the  time  of  exposure  is 
either  a  puncture  of  the  glass  wall  of  the  tube  or  fusing  the  platinum 
coating  on  the  anticathode.  A  secondary  coil  which  burns  out  in 
consequence  of  too  heavy  a  current  is  a  total  wreck  and  may  do  con- 
siderable damage  to  its  surroundings.  The  thousands  of  feet  of  fine 
wire  are  insulated  in  a  mass  of  wax.  and  when  the  wire  fuses  from  an 
overcharge  the  wax  melts  and  fairly  explodes.  Of  course,  every  coil 
is  made  to  stand  a  current  of  a  certain  strength  and  for  a  certain  length 
of  time  and  this  limit  should  not  be  exceeded.  An  exposure  of  one 
hundred  seconds  with  a  primarv  current  of  1_  to  !•"">  amperes  may  often 
be  advantageously  divided  into  three  of  about  thirty  seconds.  Several 
exposures  of  fifteen  seconds  separated  bv  intervals  to  allow  the  tube  to 
cool  often  give  the  best  results.  Very  few  tubes  indeed  will  maintain 
the  same  degree  of  vacuum  during  one  hundred  seconds  with  a  charge 
produced  by  a  current  of  12  to  15  ampere.-,  and.  of  course,  alter  a 
marked  change  has  taken  place  the  balance  of  the  exposure  is  worse 
than  wasted.  During  this  time  the  patient  must  repeatedly  be  cautioned 
to  stay  still  and.  of  course,  it  is  gomu'  to  be  best  to  have  the  plate  Hat 
upon  a  table  with  the  part  to  be  radiographed  resting  upon  it. 


814  MKDICAL    KLKCTUICITY    AND    KoNTGKX    KAYS 

Radiographs  of  the  head  or  abdomen  with  a  single  uninterrupted 
exposure  without  injury  to  the  tube  may  lie  made  with  a  heavy  anti- 
cathode  tube,  such  as  the  high-frequency  tube  described  on  p.  7(i(>,  a 
12-inch  induction-coil,  a  primary  current  of  IS  :imperes.  and  an  exposure 
of  thirty  seconds.  This  is  the  time  required  fora  photographic  plate, 
but  it  may  be  reduced  to  1  hree  or  four  seconds  if  a  celluloid  film  between 
two  intensifying  screens  is  used. 

Rapid  radiography  is  obtained  with  alternating  or  direct  current 
transformers.  Pelvic  pictures  in  one  or  two  seconds,  thorax  in  one- 
quarter  second  (see  p.  747;  also  Exposure  Tables,  pp.  S(,MMH)2). 

ililnt'rt  Sj/<<>/  »f  ]  nrinus  .i'-R(!]i  AppordtKK  mifl  Tccfinic. — If  reg- 
ulated to  a  4-  or  .Vinch  spark,  as  the  case  may  be.  while  the  tube  is  in 
operation  and  if  there  is  proved  to  be  no  inverse  discharge  the  milli- 
amperage  forms  a  reliable  direct  measure  of  the  speed.  For  instance, 
as  compared  with  the  author's  exposure  table-,  twice  the  milliamperes 
would  requre  only  one-half  the  exposure:  or  one-third  the  milliamperes 
would  require  three  times  the  number  of  seconds  exposure.  There  is 
no  change  in  the  picture. 

\aryinir  the  spark  equivalent  without  changing  the  milliamperage 
has  such  a  great  effect  upon  the  speed  that  a  h'-inch  spark  equivalent 
has  twice  the  speed  of  a  ">-inch  and  four  tunes  t  he  speed  of  a  4-inch  spark. 
With  the  longer  spark  there  i<  much  less  contrast  in  the  picture. 

Increasing  the  spark  and  reducing  the  milliamperage  without 
changing  the  power  and  the  ratio  of  transformation  increases  the  speed 
and  reduce<  the  contra-t.  It  makes  the  radiation  more  suitable  for 
thick  portions  like  the  head,  anteroposteriorly,  and  less  suitable  for 
thin  portions,  like  the  teeth,  or  for  portions  requiring  great  contrast,  as 
in  examining  for  renal  calculus. 

These  facts  reu'ardinu'  radiographic  .r-ray  exposures  apply  to  both 
electron  discharge  tubes  like  the  Coolidge  tube  and  also  to  gas-filled 
tube-.  And  the  more  closely  one  conforms  in  the  use  of  the  latter  to 
the  -park  and  miliiampere  factors  which  have  been  learned  from  the 
use  of  the  (  'onlidge  tube,  the  better  will  the  radiographs  be  and  the  less 
will  be  the  weai1  and  tear  upon  the  gas-filled  .r-ray  tube. 

Uiln'iri  ,^/itt/i  n]  l)i '  n't  n  //I  I'lutis  //in!  I- *  I  in*  nx  ('cnipnvcd  in'Hi  tin 
,\,i</  .r-lf/ii/  J'lafi*.-  The  Lumiere  .r-ray  plate  is  a  trifle  faster  The 
.r-ray  plate  is  much  faster,  the  maker-  say  about  three  times  as 
h'-  Imperial  ./'-ray  plate  seems  ab«nit  one  and  a  half  times  as 
The  Diagnostic  .r-ray  plate  wa-  formerly  one  and  a  half  times  as 
nd  later  seemed  to  be  only  two-thirds  a-  fast.  The  Kastman 
i/ed  ./--ray  film  i-  -1'mhtly  -lower.  The  Ka-tman  positive  cinema- 
film i-  one-fifteenth  to  one-fifth  as  ta-1.  depending  upon  the 
ci  IIP  lit  i'  m-  i  if  t  he  test. 

The  Nature  of  the  Materials  in  Contact  With  the  Plate.-  The  usual 
pract  in-  u sei]  f  1 1  be  to  place  an  .r-ray  plate  in  a  Mark  envelope  and  outside 
of  tin-  an  orange  envelope.  Tins  mu-t  be  done  m  absolute  darkness  or 
else  in  a  photographer's  dark-room  illuminated  only  faintly  by  a  ruby 
lamp.  The  film-surface  of  the  plate  may  be  recojjni/ed  by  its  dull  re- 
fler-  jon  of  t  he  ru  by  1  i  tiln  .  and  if  necessa  ry  by  I  he  fact  that  a  moistened 
firmer-tip  will  stjck  hidnlv  to  it.  In  placmir  n  in  the  envelopes  care 
should  be  taken  not  to  -cratch  the  film-surface  or  to  touch  it  with  the 
finirei's.  I-'.i' her  of  ihe-e  will  produce  a  mark  upon  the  plate  and  mar 

the   pjct  Ul'e.        The   ]  ila  I  e-   -hoi]  Id    not    be   placed    Hi    t  1  le-e  en  Velopes  1  i\'  t  he 

dealer.   •  !  Im   [iccomes  damaged  and  loured  b\-  lonti'  contact   with 


TIIK    .f-KAY 


815 


the  paper,  and  I  have  rather  frequently  seen  a  line  produced  on  a  plate 
by  the  paste  used  in  making  the  envelope.      This  line  passes  down  the 
center  of  the  plate  and  produces  an  effect  similar  to  that  from  a  streak 
of  daylight    falling  upon  the  plate.      This  effect    is  not  so  ruinous  upon 
a  plate  used  for  taking  a  picture  of  the  hand,  where  the  contrast   may 
be  made  so  brilliant  that  the  slight  fogging  js  not  noticeable.      The  back- 
ground on  such  a  plate  may  be 
made  a  dense  black,  and  even 
if  the  high  lights  are  not  quite 
so  transparent   as  they  might 
be,  the  picture  may  still  prove 
very  satisfactory.     When  such 
a  plate  is  used  for  a  radiograph 
through    the    body,    however, 
the    slight    contrast   produced 
by  the  x-ray,  and  the  prolonged 
development  required,  may  re- 
sult   in   a    plate   which    shows 
principally    the    grain    of    the 
black  envelope  and  the  streak 
of  paste  down  its  center.  These 
black    and    orange   envelopes 
should  not  be  regarded  as  suf- 
ficient   protection   against   or- 
dinary light  except  just  during 
the    manipulations    of    taking 
the  picture,   and   they  are  no 
protection  at   all    against   the 
.r-ray.       The    plates    are    best 
kept   in  the  original  boxes  un- 
til shortly  before  use;  and  be- 
fore  and  after  use  should   be 
wrapped    in    opaque    material 
outside  of  the  black  and  orange  envelopes.     One  curious  plate  of  mine 
shows  all  the  printing  on  the  .r-ray  envelope,  and  this  wa-  probably  the 
effect  of  exposure  to  ordinary  light.     Needless  to  say  the  plate  was  so 
fogged  that  it  was  barely  possible  to  make  out  that  it  was  a  picture  of 
an  ankle.      Fig.  .">!<.)  is  an  example  of  a  plate  ruined   in   tills  way.      The 
ordinary  plate-holders  used  by  photographers  are  excellent  and  produce 
no  deleterious  effect  upon  the  plates,  which  can  be  kept  in  them  as  long 
as  desired.     They  afford  no  protection  against  the  .r-ray,  however,  and, 
therefore,  there  is  no  advantage  in   their  holding  more  than  one  plate 
unless   it    is  desired   to  take  two   pictures  at   the  same  time.     A  simple 
and  effective  )>l(ttc-hol</er  has  been  suggested  by  (.lagnere.1      It   consists 
of  a   box  such   as  a   do/en  or  half  a  do/en  plate-  are  sold  in,  partially 
filled  by  a  board  of  the  same  length  and  breadth  as  the  plate.      The  film 
side  of  the  plate  is  protected  from  contact  with  the  cover  of  the  box  by 
-mall  piece-  ot  cardboard  pasted  on  the  corners  of  the  same.      The  plate 
is  placed  in  such  a  box  without  any  wrapping  and  will  undergo  no  change 
from  a  chemic  effect  due  to  the  container  or  from  exposure  to  ordinary 
Im'lit .      The  presence  of  the  board  backing  inside  of  t  he  box  is  an  element 
of  safety  from  the  very  disagreeable  accident  of  having  the  plate  break. 
To  prevent  the  plate  from  breaking  when  ii.-mg  the  ordinary  black  and 
1  Archives  d'Electricite  Medic-tile.  K<>nirau\.  Dec.  1<>.  UMM 


816  MEDICAL    KI.KCTHH  ITY    AND    KOVHIKX     KAYS 

orange  envelopes,  the  whole  may  bo  placed  in  a  plate-holder  made  of 
wood  with  a  shallow  depression  and  a  thin  wooden  cover. 

Two  plates  face  to  face  in  light-proof  envelopes  remain  in  good  con- 
dition for  a  long  t  hue. 

Aluminum  C/txxtttt*  a*  Plate-holders, — These  are  made  to  hold  a 
plate  or  film  pressed  into  close  contact  with  an  intensifying  screen  and 
protected  from  light  by  a  front  of  aluminum  which  is  very  transparent 
to  .r-rays.  If  the  screen  is  fastened  in  the  cassette,  as  is  very  desirable, 
the  effect  of  the  screen  may  be  prevented  by  covering  the  latter  with  a 
sheet  of  black  paper. 

Cardboard  carriers  for  films  are  made  by  the  Kastman  Kodak  Com- 
pany. They  prevent  the  abrasion  marks  which  would  come  from 
pushing  a  film  into  and  pulling  it  out  of  an  envelope  and  from  irregular 
pressure  by  the  patient  during  the  exposure. 

Stereoscopic  Radiography.-  A  tunneled  plate-holder  is  useful  for 
stereoscopic  radiography,  in  which  case  it  is  necessary  to  take  successive 
pictures  on  two  different  plates  which  are  placed  in  exactly  the  same; 
position  and  without  any  movement  on  the  part  of  the  patient. 
The  .r-ray  tube  is  shifted  a  few  inches  after  the  first  exposure  and  the 
distance  lhat  it  is  moved  corresponds  with  the  thickness  of  the  part  and 
the  distance  of  the  tube  from  the  plate.  The  result  is  two  different 
pictures  which  may  be  optically  fused  into  one  picture  by  examining 
both  original  plates  in  \Yeigd's  modification  of  the  \\heatstone  stereo- 
scope, or  by  examining  reduced  copies  of  both  plates  in  the  ordinary 
hand  stereoscope  with  its  prismatic  lenses.  Ordinarily  in  looking  at 
anv  object  oi1  group  of  objects,  of  course,  each  eye  sees  quite  a  different 
picture,  but  the  brain  combines  the  two  impressions  into  one  picture, 
which  has  the  property  of  perspective.  This  enables  us  to  recognize 
at  a  glance  whether  one  part  of  the  object  is  project  ing  toward  or  away 
from  us.  and  this  without  any  regard  to  the  relative  size  of  its  image. 
Of  course,  skilful  drawing  will  sometimes  cause  an  image  on  a  flat 
surface  to  appeal1  to  stand  right  out.  Theoretically,  the  two  pictures 
in  stereoscopic  photography  or  stereoscopic  radiography  should  be  taken 
from  point-  of  view  just  as  far  apart  as  the  pupils  of  th"  two  eyes,  but 
practicallv  it  has  been  found  desirable,  both  wilh  the  camera  and  with 
the  .r-ray,  to  vary  this  distance  in  accordance  with  the  subject  of  the 
picture.  In  other  words,  it  is  often  necessary  to  exaggerate  or  diminish 
the  stereoscopic  effect  in  order  to  product'  the  best  perspective.  'The 
following  table,  worked  out  bv  Mane  ami  llibaut.1  is  a  useful  guide,  but 
;is  lon.Li  as  the  distance  lhat  the  lube  is  shifted  is  recorded,  the  exact 
d  1st  a  lice  <j,\\  en  in  t  he  t  aide  net  d  not  be  followed : 


I  .'.I  'J  7 

ic.il*'.  H<>nl<'.-ui\.  .lulv  l.~>, 


THE    Z-KAY  817 

This  must  ho  modified  in  certain  cases,  for  instance,  where  we  wish 
to  show  the  relative  position  of  ihe  vertebra1  and  a  renal  calculus  or  a 
bullet  embedded  near  the  spine.  In  these  cases  we  would  use  the 
number  corresponding  to  a  much  less  thickness  of  tissue  than  if,  for 
instance,  we  wished  to  show  the  anatomic  relations  of  the  chest.  In 
general,  the  nearer  the  objects  of  chief  interest  are  to  the  plate,  the 
greater  is  the  distance  that  the  tube  must  be  shifted  between  taking 
the  first  and  the  second  radiograph. 

There  is  required  a  convenient  means  of  removing  the  first  plate 
and  placing  another  in  exactly  the  same  position,  or,  according  to 
Caldwell's  suggestion,  metallic  portions  of  the  plate-holder  projecting 
over  The  edge  of  the  plate  and  by  their  image  indicating  exactly  corre- 
sponding parts  of  the  two  plates.  The  plates  may  be  pushed  into  a 
slot  and  removed  without  any  movement  of  patient  or  stereoscopic  plato- 
holder. 

The  tube-stand  designed  by  Brickner,  of  Xew  York,  serves  a  very 
useful  purpose  in  stereoscopic  radiography.  There  is  an  upright 
hollow  wooden  shaft  in  which  plays  a  counterbalance  like  a  sash- 
weight  of  a  window.  The  saxh-cord  is  attached  to  a  carrier,  which  in 
this  way  may  be  raised  or  lowered,  and  remains  in  position  without  any 
fastening  or  unfastening.  Through  this  carrier  then1  passes  a  hori- 
zontal arm  which  is  also  adjustable  and  self-retaining.  At  the  (Mid  of 
the  horizontal  arm  is  the  tube-holder,  adjustable  in  every  direction 
and  secured  by  heavy  screws.  There  is  a  scale  of  inches  upon  the 
vertical  shaft  and  upon  the  horizontal  arm,  and  the  tube  can  be  moved 
a  measured  distance  in  either  of  these  directions  without  fastening  or 
unfastening  anything.  The  motion  is  made  by  a  rack  and  pinion 
effect  of  friction  wheels. 

Rippcrger's  modification  of  this  stand  includes  a  box  large  enough 
to  enclose  the  .r-ray  tube  and  of  material  that  is  opaque  to  the  .r-ray. 
This  is  an  element  of  safety  for  the  operator. 

The  same  tube-stand  or  its  modification  is  useful  for  most  of  the 
applications  of  the  x-ray  in  diagnosis  and  treatment:  It  makes  it  very 
easy  to  place  the  tube  in  the  exact  position  required;  it  is  also  sub- 
stantial enough  in  construction  to  carry  a  Friedlander  shield;  and  the 
fact  that  there  is  very  little  metal  about  it  makes  the  arrangement  of 
the  conducting  cords  an  easy  matter.  With  a  stand  made  largely  of 
metal,  of  course,  the  Conducting  cords  should  not  be  allowed  to  touch 
any  but  the  appointed  part  of  the  stand,  as  otherwise  there  would  be 
a  spark  and  more  or  less  waste  of  power  and  damage  to  the  cords. 
Whatever  be  the  construction  of  the  stand,  the  clamp  should  grasp  the 
tube  by  its  principal  prolongation  surrounding  the  cathode  stem,  and 
not  by  the  little  projection  from  the  tube,  which  is  made  for  the  principal 
purpose  ot  connection  with  the  air-pump  when  the  tube  is  being 
exhausted.  Care  must  always  be  taken  to  prevent  the  patient  receiving 
a  spark  from  the  conducting  cords  or  from  the  points  of  the  tube. 
There  is  a  disagreeable  but  not  injurious  shock  received,  which  would 
be  accompanied  by  a  burn  if  for  any  reason  the  patient  were  unable  to 
break  the  contact  bv  an  instinctive  or  rellex  movement.  Contact 
with  both  wires  at  once  would  be  productive  ot  a  very  serious  shock. 

I'il/coi/'s  Mirror  N/r/rasro/x'. — This  is  one  of  the  simplest,  least 
cumbrous,  and  best  instruments  for  examining  stereoscopic  radio- 
graphs, prints,  or  negatives.  The  plates  or  prints  are  placed  on  two 


SIS 


MEDICAL    KLECTKK'ITY    AND    RONTGEX    KAY.s 


sheets  of  ground  glass  while  the  observer  looks  directly  at  the  right-hand 
picture,  and  at  the  xinie  time  sees  the  reflection  of  the  other  picture 
in  a  small  triangular  mirror  iFig.  520,  M).  This  is  made  by  Radiguet 
and  Massiot.1 

Stcreoradioyrapfu/  Without  <i  Stereoscope. — This  process,  suggested 
by  (iuillo/..-  consists  in  making  two  successive  pictures  upon  the  same 
plate,  shifting  the  .r-ray  tube  the  proper  distance  after  the  first  exposure. 
A  wire  net  screen  is  used  during  the  exposures  and  also  for  looking  at 
the  completed  picture. 

Sti  n  (ixco/iic  I-'htaroxcopi/. — The  most  practical  method  is  by  having 
two  .r-ray  tubes  excited  at  the  same  time  by  an  alternating  current,  and 
having  a  synchronous  shutter  which  allows  each  eye  to  see  the  fluores- 
cent screen  only  during  the  periods  that  it  is  illuminated  by  the  proper 
tube. 

A   sufficiently   pmve-ful   tran>former  will   do   this   if  there  are   two 


circuits  each  made  up  of  an  .r-ray  tube  and  a  vntril  tube.      The  .r-ray 
•  ut  ies    have   opposite    polarit  ies. 

Ynhn  «f  SttTdn'inlioi/rd/ilit/.  Stereoscopic  radiography  is  useful  in 
depicting  -abject-  like  renal  calculi  and  fractures  of  the  femur,  but  for 
the  location  of  foreign  bodies  better  re-nlts  are  obtained  by  the  com- 
parison of  two  different  radiographs  taken  at  a  very  much  wider  angle. 

The  Nature  of  the  Material  Back  of  the  Plate. — In  using  the 
ordinary  black  and  orange  envelopes  a  distinct  effect  is  often  produced 
on  the  plate  whi"li  r-  analogous  to  a  reflection  trom  l  he  surface  upon 
which  'lie  plate  with  ils  envelopes  rests.  In  reality  this  effect  i>  due 
"  o  -erondarv  ra  vs  caused  bv  t  iie  impact  ot  t  h<-  ./'-ray  upon  t  he  material 

back   o|    the    plate.       The.-e   secondary    l'a\>   fill    the  entire  J'-l'aV    room   alld 

are   difTu-'i-d    in   everv   direction,    and    unless   prevented   bv    something 

opa'jue  to  them  an  extraneous  effect  will  be  produced  on    the  plate  from 
two  sources:    1'irst,   bv    secondary    rays    ari.-m^   trom   the  direct  ./'--ray 


THE    X-RAY  819 

which  has  passed  through  the  plate  and  encounters  wood  or  metal  or 
glass,  etc.,  close  behind  tlie  plate;  and  second,  by  secondary  rays  arising 
from  the  .r-ray  reaching  various  parts  of  the  room  without  having  passed 
through  the  part  to  be  depicted.  Imagine  a  brilliant  electric  light 
out  in  the  open  air  on  a  dark  night  and  an  opaque  body  like  a  thick 
paper-covered  volume  held  so  that  the  light  shines  vertically  upon  one 
cover;  we  should  find  that  the  lettering  on  the  other  cover  was  not 
lighted  enough  to  be  seen.  Hut  now  take  the  same  brilliant  electric 
light  into  an  ordinary  room,  and  the  diffused  light  from  every  part  of 
the  room  will  be  so  bright  that  the  lettering  on  the  shaded  side  of  the 
volume  can  be  read  very  well.  An  analogous  condition  is  produced  by 
the  .r-ray,  but  the  secondary  rays  are  so  much  less  powerful  than  the 
direct  rays  that  they  only  become  a  disturbing  factor  when  the  direct 
rays  are  weakened  by  passage  through  thick  tissues,  and  the  effect  of 
the  secondary  rays  is  increased  by  the  length  of  exposure  required. 
In  taking  a  chest  or  a  pelvic  picture,  if  there  is  an  irregular  backing  of 
wood  and  metal  with,  perhaps,  an  air  space,  the  evidence  of  this  will  be 
found  upon  the  plate,  and  I  have  been  consulted  about  such  pictures 
which  had  proved  quite  a  puz/le  to  the  radiographer.  It  is  my  own 
practice  to  use  a  backing  of  .r-ray  metal,  lead  and  tin,  about  3  milli- 
meter thick,  behind  the  plate  but  outside  of  its  envelopes.  This 
cuts  off  any  influence  coming  from  behind,  and  whatever  secondary 
rays  are  generated  upon  its  surface  are  in  proportion  to  the  amount 
of  x-ray .s  striking  it j  so  that  to  a  certain  small  extent  it  acts  also  to 
intensify  the  image  on  the  plate.  If  only  a  part  of  the  plate  is  protected 
by  the  ./'-ray  metal  backing,  the  part,  which  rests  upon  the  uncovered 
wooden  table  is  a  very  great  deal  darker  than  the  other,  and  in  some 
plates  shows  even  the  grain  of  the  wood.  It  is  evident  that  wood 
either  has  a  much  greater  capacity  for  induced  .r-radiance  than  lead,  or 
that  it  is  transparent  to  the  secondary  rays  coining  from  various  parts 
of  t  he  room. 

Two  plates  may  be  placed  on  top  of  each  other,  both  in  separate 
black  and  orange  envelopes,  and  a  picture  be  made  upon  both  at  the 
same  t  ime,  and  sometimes  the  picture  upon  the  lower  plate  is  the  better. 
The  lower  plate  receives  only  about  two-thirds  as  strong  an  impression 
from  the  direct  .r-ray  because  the  upper  glass  plate  is  not  nearly  as 
transparent  to  the  x-ray  as  glass  is  to  ordinary  light.  The  lower  plate, 
therefore,  is  not  as  dense  as  1  he  upper,  but  t  he  image  on  it  is  somel  imes 
clearer  because  the  upper  plate  often  almost  entirely  cuts  off  the 
less  penetrating  secondary  rays  arising  from  the  .r-ray  tube.  The 
./•-radiance  excited  in  the  thicker  tissues,  like  the  liver,  is  the  chief 
source  of  indistinctness  in  radiographs  through  such  pails  of  the  body, 
and  this  indistinctness  may  be  somewhat  reduced  by  having  the  film 
surface  of  the  plate  down,  or  bv  using  two  plates.  My  experiments 
with  a  thin  metallic  screen  over  the  plate  have  not  thus  far  resulted  in 
improvement  in  the  image  produced.  The  use  of  a  diaphragm  or 
cylinder  to  cut  off  the  secondary  rays  from  the  ./'-ray  tube  reduces  this 
indistinctness  very  decidedly. 

A  practical  point  to  be  observed  is  in  connection  with  the  perspira- 
tion which  may  be  present  upon  the  surface  of  the  part  in  contact  with 
the  x-ray  envelope.  If  this  strikes  through  the  envelope  it  will  produce 
a  chemic  effect  upon  the  film,  resulting  in  a  picture  in  which  the  print 
will  be  seen  spotted  with  white  dots.  To  prevent  such  an  accident  it  is 


MJU  MKDK  AI.    ELECTRICITY    AM)    Ko.VTe.KX    KAYs, 

well  to  always  have  a  piece  of  blotting-paper  between  the  x-ray  envelope 
and  the  part  of  the  body  resting  upon  it,  unless  two  plates  are  used  face 
to  face  in  the  same  envelope. 

Marking  the  Plate  for  Identification.— Lead  or  other  metallic 
figures  and  letters  may  be  placed  upon  the  upper  surface  of  the  plate, 
outside  of  its  envelopes,  and  at  the  same  time  that  the  radiograph  is 
made  an  image  of  these  is  also  impressed  upon  the  plate,  and  is  repro- 
duced in  every  print  made  from  it.  My  own  custom  is  to  have  my 
name  and  the  serial  number  of  the  plate,  and  sometimes  the  word 
"right"'  or  "left."  Such  a  word  is  necessary  in  every  case  in  which 
two  ,-ymmetric  portions  appear  upon  the  same  plate,  like  the  two  side- 
of  the  pelvis,  or  both  shoulders,  or  both  knee-,  unless  there  is  known 
to  be  some  striking  difference  which  will  enable  us  to  identify  the  two 
side.-.  It  is  possible  to  be  pretty  sure  that  a  certain  side  of  the  plate 
represents  t  he  right  side  of  the  body  if  we  make  a  practice  of  having  the 
film-side  of  the  plate  uppermost,  and  have  a  record  of  the  position  of 
the  patient,  whether  prone  or  supine.  Hut  this  calculation  would  be 
based  upon  the  assumption  that  the  plate  was  correctly  placed  in  the 
x-ray  envelope,  and  when  a  person  is  to  be  operated  upon  for  a  stone 
in  the  kidney  it  is  necessary  that  there  should  be  no  possibility  of  error 
as  to  which  kidney  it  is  that  the  x-ray  picture  shows  the  stone  to  be  in. 
In  the  absence  of  any  special  metal  letters  any  suitable  object .  like  a 
key  or  a  coin,  may  be  laid  upon  the  side  of  the  [date  upon  which  rests 
the  riiiht  side  of  the  body.  A  written  note  to  that  effect  should  be  made 
before  the  exposure  is  finished.  If  not  made  while  the  plate  and  the 
marker  and  the  patient  are  all  in  the  same  relative  positions,  the  iden- 
tification of  the  right  and  left  sides  of  the  patient  in  the  picture  again 
becomes  a  matter  of  memory  and  calculation.  The  letters  and  fig- 
ures I  use  are  r-at  from  x-ray  metal  about  \  millimeter  thick.  If 
the  plan  is  film  — ide  up,  the  letters  and  figures  must  be  completely 
reversed  when  laid  on  top  of  the  plate  in  order  that  they  shall  appear 
in  their  proper  relation  on  the  print:  but  if  it  accidentally  happen- 
that  they  are1  not  put  on  in  this  reversed  peisition,  it  may  later  be 
bv  printing  the  picture  with  the  ulass  instead  of  the  film-side 
ate  in  contact  with  the  velo.x  paper  in  the  printing  frame, 
it  convenient  to  have  all  the  letter-  of  the  name  pasted  in  a 
po.-it  ion  upon  a  card,  and  to  have  the  -mule  figures  past  eel  upon 
i  a  rd  slips,  which  fit  m  a  sort  ot  pocket  on  t  he  name  card,  t  oget  her 
-lip  on  which  i-  pasted  either  "riuht"  or  "left  "  An  x-ray 
•  •  a  '  raiisparency :  if  you  are  looking  t  hrou:Ji  from  one  direct  ion 
re  of  two  hands  the  hand  with  the  wedding  riim  on  it  may 
be  the  left  hand,  and  if  you  look  through  the  plate  in  tin 
iirection  that  hand  will  appear  to  be  the  right  one.  In  a 
e  of  the  two  hands  taken  upon  a  plate  with  the  film-side  up.  the 
hand  with  the  wcddinii  rim:  on  it  will  appear  to  be  the  left  hand:  but 
i-  down,  as  it  usually  is  in  the  print,  the  picture  will 


RADIOGRAPHY 


i  n    t  in    mteri  K  i.-it  ion  of  t  h 


821 

depicted  between  the  x-ray  tube  and  the  sensiti/ed  surface.  The 
effect  produced  upon  the  plate  is  the  same  as  that  produced  by  light  in 
ordinary  photography,  and  the  plate  is  subsequently  developed  by  the 
same  processes  lhat  are  employed  with  daylight  pictures.  The  back- 
ground of  the  picture  on  the  plate  is  produced  by  the  unimpeded  action 
of  the  x-ray,  the  half-tones  by  the  action  of  the  ray  but  slightly  dimin- 
ished by  traversing  the  flesh,  which  in  thin  layers  is  generally  as  trans- 
parent to  the  x-ray  as  glass  is  to  ordinary  light;  the  bones  and  metallic 
substances,  on  the  ot  her  hand,  cast  deep  shadows,  and  on  those  port  ions 
of  the  plate  the  photochemic  effect  is  but  slight.  An  ideal  plate  K 
one  in  which  the  images  of  the  bones,  and  especially  of  metallic  foreign 
bodies,  are  nearly  transparent,  but  with  fine  detail  showing  the  structure 
of  the  bones;  and  the  background  is  dense,  almost  opaque.  A  "  print. '' 
or  the  finished  picture,  of  which  as  many  as  are  desired  may  be  copied 
on  sensitized  paper  from  such  a  plate,  shows  the  bones  black  with 
excellent  detail  of  structure,  contrasting  sharply  with  the  half-tones  of 
the  flesh,  and  the  outline  of  the  latter  is  clearly  defined  upon  the  pure 
white  background.  Such  a  picture  can  be  obtained  by  what  I  have 
called  a  "normal  exposure,"  meaning  by  that  term  the  equivalent  of 
the  conditions  necessary  for  perfect  ordinary  photographs.  With  an 
ordinary  photograph  the  amount  of  light  and  shade  upon  the  object, 
and  the  amount  of  light  admitted  to  the  camera,  and  the  length  of  time 
during  which  it  is  allowed  to  act  upon  the  plate,  are  all  very  commonly 
under  complete  control.  \Yith  the  .Rom gen  ray.  however,  it  is  only 
exceptionally  that  it  is  possible  or  desirable  to  secure  all  the  gradations 
between  opaque  density  and  almost  perfect  transparency.  With  the 
hand  and  foot  a  normal  exposure  can  readily  be  obtained,  but  with  the 
thickest  portions  of  the  body  this  is  entirely  impracticable. 

The  plate  is  usually  contained  in  an  opaque  black  envelope,  and 
outside  of  this  there  is  one  of  orange  paper,  and  thus  enveloped  it  is  as 
safe  from  ordinary  light  of  moderate  strength  as  a  plate  in  a  plate- 
holder  or  a  film  in  a  camera.  These  envelopes  ordinarily  present  no 
impediment  at  all  to  the  passage  of  the  Rontgen  ray  and  the  plate  must, 
therefore,  not  be  kept  in  or  even  near  the  room  in  which  the  x-ray  is 
turned  on.  except  during  the  actual  exposure  for  taking  the  radiograph. 
Such  a  plate  in  its  envelopes  may  be  placed  upon  a  table,  the  hand  or 
whatever  part  is  to  be  radiographed  is  placed  upon  it.  and  the  x-ray 
tube  placed  directly  above  this  at  a  distance  from  the  plate  which 
bears  a  distinct  relation  to  the  si/.e  of  the  plate  and  to  the  thickness  of 
i  lie  part  to  be  penet  rat ed.  The  ./'-ray  is  turned  on  tor  the  proper  length 
of  time  and  the  picture  has  been  taken,  it  being  only  necessary  then 
either  to  develop  it  one's  self  or  give  the  plate  to  a  professional  photog- 
rapher for  development.  There  are  differences  between  the  develop- 
ment required  for  most  x-ray  plates  and  that  used  by  the  ordinary 
photographer  whose  plates  have  all  had  approximately  normal  exposures. 
These  special  points  are  detailed  in  the  chapter  on  the  development 
of  x-ray  pict un-s. 

Some  of  the  factors  to  be  considered  in  making  a  radiograph  are  the 
<lixhin<-(  from  the  plate  to  the  tube,  the  position  of  the  portion  to  be 
radiographed,  the  degree  of  vacuum  in  the  tube,  the  strength  of  the 
primary  current,  the  rate  and  charactei  of  the  interruptions  in  the 
primary  current,  the  self-induction  in  the  primary  coil,  the  presence  or 
absence  of  -park-gaps  between  the  secondary  coil  and  the  tube,  and  the 


S22  MEDICAL    KLKCTIUCITY    AND    KOXTCEN    RAYS 

amount  of  current  passing  through  the  tube.  The  sensitiveness  of 
the  plate  or  film,  the  duration  of  exposure,  and  the  nature  of  the  material 
back  of  the  plate  are  also  important.  It  is  only  by  a  proper  combination 
ot  all  these  elements  that  the  best  results  can  be  obtained,  and  the  only 
ways  in  which  one  may  hope  to  improve  in  technic  are  first  to  study 
the  recorded  experience  of  others,  and  second,  to  make  a  most  pains- 
taking record  of  all  the  particulars  in  regard  toeach  exposure  made  by 
one's  self. 

The  tube  ought  to  be  at  such  a  distance  from  the  plate  as  to  produce 
a  nearly  uniform  amount  of  photochemic  effect  upon  all  parts  of  the 
plate.  In  the  case  of  a  little  tooth-film,  an  inch  and  a  quarter  by  an 
inch  and  three  quarters,  the  anode  will  be  practically  equally  distant 
from  all  parts  of  the  film  at  13  inches,  which  is  the  shortest  distance  to  be 
recommended  for  radiography.  This  distance  is  measured  from  the 
anticathode  to  the  surface  of  the  film.  But  with  a  plate  measuring 
14  by  17  inches  the  tube  must  be  about  23  inches  away  in  order  that 
there  shall  be  anything  like  a  uniform  action.  The  action  of  the.r-ray 
diminishes  rather  more  rapidly  than  the  square  of  the  distance,  and  if 
the  distance  from  the  tube  to  the  center  of  such  a  plate  were  only 
'.(  inches,  it  is  easily  seen  that  portions  of  the  plate  S  or  9  inches  from  the 
center  would  be  almost  twice  as  far  away  from  the  tube  as  the  center 
of  the  plate.  The  action  produced  upon  the  peripheral  parts  of  the 
plate  would,  in  such  a  case,  be  only  about  a  quarter  as  intense  as  upon 

the  center. 

Again,  the  distance  must  bear  a  certain  relation  to  the  nature  of 
the  part  to  be  radiographed  in  order  not  to  produce  imperfect  or  mis- 
leading effects,  such  as  distortion.  If  the  portion  to  be  radiographed  is 
comparatively  small  and  can  be  placed  in  close  contact  with  the  plate, 
like  one  phalanx  of  the  finger,  the  tube  may  be  placed  at  the  minimum 
distance.  But  when  the  object  is  large  and  parts  of  it  are  at  different 
distances  from  1  he  surface  of  the  plate,  and  from  the  direct  line  from  the 
tube  to  the  center  of  the  plate,  the  tube  must  be  far  enough  away  to 
produce  approximately  parallel  rays.  A  desirable  maximum  distance 
lias  seemed  to  be  30  inches.  A  greater  distance  would  give  still  less 
distortion,  but  would  require  a  longer  and  stronger  exposure:  and 
with  a  much  shorter  distance  the  portions  far  from  the  surface  of  the 
plate  appear  unduly  magnified  as  compared  with  those  portions  near 
'he  plnte.  This  is  like  the  magnified  shadow  of  a  hand  held  near  a 
candle,  while  if  the  hand  is  quite  near  the  wall  the  shadow  is  only  the 
nut  ural  si/e. 

Diffused  Radiation.  Another  feature  which  has  a  bearing  upon 
the  q  ue.-;  ion  ol  distance  is  t  he  tact  that  an  appreciable  amount  ot  ./'-ray 
radiates  from  all  the  different  parts  of  the  tube.  This  is  well  shown  in 
the  picture  of  a  pennv  right  in  the  shadow  of  a  silver  dollar  (Fig.  521). 
In  making  this  the  pennv  was  close  to  the  plate  and  the  dollar  half-way 
li'om  the  plate  to  the  tube  in  such  a  position  as  to  completely  exclude 
1 1 ;  eci  m  vs  from  t  he  focus  point ,  or  any  ot  her  pa  rt  of  t  he  anticathode, 
reaching  the  part  of  the  plate  on  which  the  pennv  rested.  Havs 
from  the  walls  of  the  tube  passed  in  straight  lines  and  met  at  an  angle 

iind   the  dollar  and   there  produced  a   picture  of  the  pennv.      That    it 

-  ilii-  and  not   partial  transparency  ot  the  metal  disk  is  shown  bv  the 

•  r  picture   m    whi'-h   the  dollar  is  nearer  to  the   plate,  and  in   which 
linage  "1   'he  pennv  cannot   be  seen.      This  is  an  observation  which 


T1IK    .r-HAV 

may  be  confirmed  by  means  of  the  fluoroscope.  Its  practical  value 
consists  in  the1  knowledge  that  the  image  of  anything  at  a  distance  from 
the  plate  is  sure  to  be  more  or  loss  ha/y  in  consequence  of  this  penumbra, 
and,  of  course,  the  nearer  the  tube  is  the  greater  is  the  angle  which  the 
rays  from  its  walls  make  with  its  focus  rays;  blurring  of  the  image  which 
results  from  having  the  tube  too  near  when  the  point  of  interest  is  not 
in  absolute  contact  with  the  plate. 

An  example  of  the  blurring  from  diffused  radiation  is  seen  when  the 


ravs   in  the  shadow  of  a  .-liver 


hand  with  outstretched  fingers  is  held  outside  a  window-shade  not 
exposed  to  direct  sunlight.  When  the  hand  is  pressed  against  the 
shade  its  shadow  is  clearly  visible  with  its  outstretched  fingers  and  tin- 
spaces  between  them,  but  when  the  hand  is  held  a  few  inches  outside 
of  the  cloth  its  shadow  cannot  be  distinguished. 

The  diffused  secondary  .r-rays  passing  through  an  object  at  a  dis- 
tance from  the  plate  would  not  only  gi\  e  a  blurred  image  of  their  own 
but  would  also  blur  the  image  due  to  the  direct  rays. 

The  author  cannot  help  feeling  that  the  secondary  r<n/x  anWm/  hi 
the  //.N'.V//CN  are  partly  the  source  of  our  ability  to  make  radiograph.-,  such 
as  t  hose  of  the  frontal  sums,  at  all.  iSome  cases  of  his  have  shown  t  wo  or 
three  times  as  great  discoloration  of  the  photographic  plate  at  the 
image  of  the  frontal  sinus  on  the  sound  side  as  upon  the  side  where  a 
subsequent  operation  revealed  the  presence  of  only  one  or  two  tea- 
spoonfuls  of  pus.  The  direct  rays  passing  through  the  entire  thickness 


,S24  MKDICAL     KI.KCTKH   ITY     AM)    KO.NTCK.N     HAYS 

of  the  scalp,  skull,  and  brain  would  encounter  only  a  very  small  fraction 

of  u'reater  total  density  on  one  side  than  on  the  other.     This  would  not 
fully  account   for  the  great   visible  difference  in  the  resulting  images. 

If  we  suppose  that  every  particle  of  matter  in  the  head  is  emitting 
secondary  rays,  we  should  at  once  expert  that  differences  in  density  of 
the  skull  at  various  points  would  arrest  different  proportions  of  the 
radiance  from  within,  and  show  a  difference  in  the  radiograph. 

This  explanation  is  rendered  all  the  more  plausible  by  the  con- 
sideration that  secondary  rays  have  comparatively  little  penetration 
and.  consequently,  it  is  only  the  radiation  from  the  portion  near  the 
plate  that  is  concerned  in  the  production  of  the  image.  A  difference 
of  a  certain  fraction  in  the  density  of  the  skull  at  the  part  nearest  the 
plate  would  make  a  difference  of  almost  as  great  a  fraction  in  the  total 
resistance  encountered  by  the  secondary  rays  reaching  the  two  parts 
of  the  plate,  ll  is  true  that  secondary  rays  arise  from  this  part  of  the 
skull  itself,  and.  doubtless,  in  proportion  to  i's  density,  and  this  aids  in 
the  production  of  a  good  image  if  the  plate  is  very  near.  Secondary 
rays  would  also  arise  from  the  skin  in  proportion  to  the  rays,  direct  and 
secondary,  which  reached  it,  and  would  tend  to  reinforce  a  clear  image 
upon  a  plate  in  contact  with  it. 

This  is  given  as  the  author's  theory,  not  as  an  established  fact. 

If  parallel  rays  could  be  obtained  from  an  .r-ray  tube  this  blurring 
of  the  image  of  parts  at  any  appreciable  distance  from  the  plate  would 
be  partially  prevented,  and,  furthermore,  the  image  would  be  of  exactly 
the  same  size  as  the  original  object,  no  matter  how  far  from  the  plate 
it  was,  provided  that  it  lay  in  a  direction  parallel  to  the  surface  of  the 
plate,  and  that  the  rays  fell  vertically  upon  the  plate.  This  condition 
of  parallel  rays  cannot  be  fully  accomplished,  the  .r-rays  can  neither  be 
leflected  nor  refracted,  and  the  major  part  of  them  diverge  from  a  very 
.-mail  point  in  the  center  of  the  tube,  so  that  in  a  regular  .r-ray  picture 
the  divergence  of  the  direct  rays  from  the  focus  point  on  the  anticathode 
must  produce  magnificat  ion  of  the  image  in  proportion  to  the  relative 
distance  of  the  object  from  the  plate.  The  actual  si/.e  of  the  object 
can  Usiiallv  be  determined,  closely  enough  for  all  practical  purposes,  by 
a  simple  calculation  based  upon  the  si/.e  of  the  image,  and  the  relative 
distance  from  the  object  to  the  plate  and  to  the  lube.  For  instance, 
if  the  object  were  just  half-way  between  the  anticathode  and  the  plate, 
'he  image  would  be  t  wice  the  diameter  of  the  actual  object .  Of  course, 
in  most  rases  this  is  only  approximate,  since  we  usually  do  not  know 
the  absolute  distance.  For  the  few  cases  in  which  it  is  necessary  to 
determine  the  exact  si/e  of  an  object,  for  instance,  the  heart,  resort 
must  be  had  to  the  oil  hodiagraph  described  at  length  in  the  chapter  on 
I'  luoroscopic  Fxaminat  ion. 

AHxr*  Scln'iritx /V/'N  Compression  Cylinder.-  The  compression  cylin- 
der of  Alber.s  Schnnberg  makes  no  attempt  at  ort  hodiagraphy,  but  it  is 
a  step  in  the  direction  of  eliminating  blurring  when  the  object  is  at  a 
di-tanre  from  the  plate.  It  does  this  by  cutting  off  many  of  the  extra 
ray-  an-nm  from  various  parts  of  the  tube,  and  allowing  principally 
I  he  direct  rays  from  t  he  focus  point  to  reach  the  plate.  ( )f  course,  1  hese 
are  the  original  divergent  rays  and  the  image  is  just  as  much  magnified 
H-  if  t  he  cylinder  were  not  1  here,  but  t  he  claim  is  t  hat  1  he  image  is  more 
clearly  defined.  The  compression  cylinder  itself  j>  of  brass,  lined  with 
lead  in  order  to  be  opaque  to  the  .r-ray.  and  is  about  -1  inches  in  diameter 


TIIK    .{'-KAY 


and  about  .">  inches  long.  11  forms  part  of  a  complicated  apparatus 
by  means  of  which  one  open  end  of  the  cylinder  may  be  pressed  against 
the  abdomen  or  any  other  part.  It  produces  in  all  cases  fixation,  and 
in  some  places,  like  the  abdomen,  reduction  in  the  thickness  of  the  tissues 


l-i'_r.  ~>2'2,  A. — Compression  diaphragm.      (Kelley-Koett  Company.) 

to  be  penetrated  by  the  .r-ray.  At  the  other  open  end  of  the  cylinder 
the  .r-ray  tube  is  held  in  position  by  another  part  of  the  apparatus. 
The  pictures  an1,  of  course,  limited  by  the  size  of  the  cone  of  rays  which 
passes  through  the  cylinder.  The  extra  rays  are  not  all  cut  off  by  any 


Fi<j;.  •">-"-,  B.  -Dotted  lines  arc  sec- 
ondary rays  which  would  pass  t  hroimli 
an  ordinary  diaphragm,  hut  which  are 
arrested  In  the  walls  of  the  cylinder. 


when  a  cylinder  and   diaphrag 


manner  of  means.  All  those  emanating  from  a  part  of  the  tube  4  inches 
in  diameter  are  free  to  take  part  in  the  production  of  the  picture.  It  is 
certainly  an  excellent  device  for  cases  in  which  a  small  picture  is  sufficient. 
and  in  which  it  is  possible  to  so  judge  of  the  position  of  the  object  of 


MKDICAL    ELKCTKH  ITY    AM)    KOVlXiKX    HAYS 

interest  as  to  direct  the  cylinder  accurately  enough  to  include  the  object 
of  interest  in  a  picture  only  a  little  over  4  inches  in  diameter. 

Author'*  liuit/nti nt/  Cdlnlar  Diaphragm.  —  In  the  first  edition  of 
this  work  the  author's  radiating  cellular  diaphragm  was  described. 
It  has  been  found,  however,  that  it  was  necessary  to  use  the  rluoro- 
scope  to  so  accurately  place  the  .r-ray  tube  so  as  to  cast  only  linear 
shadows  of  the  wall  of  the  central  funnel.  This  involved  a  dangerous 
exposure  of  the  operator  and  caused  the  use  of  the  apparatus  to  be  given 
up,  but  now  his  improved  apparatus  makes  it  safe  and  desirable  for  use 
with  a  lias-tilled  tube.  It  is  not  required  with  a  ( 'oolidge  tube. 

Author'.*  .r-luii/  Tithi'  irith  Radiatnnj  Diaphragm. — An  .r-ray  tube 
invented  by  the  author  has  permanently  attached  to  it  a  radiating 
cellular  diaphragm  whose  wall  is  of  thin  lead  glass  and  casts  a  narrow 
linear  shadow  because  it  is  part  of  a  hollow  cone  whose  apex  would  be 
at  the  focus  point  on  the  anticathode.  The  idea  is  useful  only  for  a 
gas-filled  tube  where  it  prevents  many  of  the  secondary  rays  from  the 
glass  wall  of  tin1  .r-ray  tube  reaching  the  plate:  and  it  does  this  without 
reducing  the  size  of  the  picture.  The  latter,  however,  does  show  a  nar- 
row rin»-;  and  the  advantage  of  having  the  cone  permanently  attached 
to  the  .r-ray  tube  is  the  saving  in  time  as  compared  with  extempora- 
neously placing  a  radiating  cellular  diaphragm  with  the  necessary  ac- 
curacy. The  .r-ray  tube  itself  may  be  of  ordinary  glass,  or  all  but  the 
portion  most  useful  for  radiography  or  fluoroscopy  may  be  of  lead 


Author'*  Radiating  Diaphragm  for  Attachment  to  .r-rai/  Tube. — A 
radiating  cellular  diaphragm  invented  by  the  author  has  the  conical 
part  of  thin  lead  glass  or  some  other  material  not  of  a  nature  to  cause 
damage  by  being  in  close  relation  with  the  .r-ray  tube  and  with  metal- 
lic parts  of  the  tube-stand.  The  conical  part  is  permanently  fastened 
to  a  part  spheric  portion  of  such  a  curvature  as  to  fit  accurately  when 
simply  bound  in  contact  with  an  .r-ray  tube  of  the  size  for  which  it  is 
designed.  And  the  conical  part  has  such  an  angle  and  is  so  directed 
that  its  wall  will  then  radiate  from  the  focus  point.  The  spheric 
part  is  of  glass  transparent  to  the  .r-ray  within  and  for  a  certain  dis- 
tance outside  the  small  end  of  the  cone.  There  is  an  advantage  in 
makintr  the  remainder  of  it  opaque  to  the  .r-ray  as  with  lead  glass. 
Thi-  i-  intended  for  use  with  a  gas-filled  tube  for  preventing  a  large 
part  of  the  secondary  .r-rays  from  the  glass  wall  of  the  .r-ray  tube 
ivai-hinii  the  plate,  while  not  interfering  with  the  direct  rays  from 
the  focus  point  except  for  a  narrow  ring  which  should  appear  as  a  mere 
line  upon  t  he  plate. 

This  i^  1  letter  because  more  easily  placed  in  the  proper  position  than 
the  radial  inii  cellular  diaphragm  fastened  to  any  part  of  the  tube 
-tand.  But  it  is  not  available  with  most  tube  stands. 

An  .r-ray  tube  of  the  proper  diameter  for  this  diaphragm  may  be 
found  not  to  have  its  focus  exactly  at  the  center  and  so  may  not  give 
the  best  results.  Instead  of  having  a  different  diaphragm  for  such  a 
tube,  the  manufacturer  may  make  the  necessary  change  in  the  position 
ot  the  focu-  or  he  may  affix  a  couple  of  slight  glass  project  ions  to  suitable 
part-  of  the  tube.  Thi-  is  done  in  such  a  way  that  now  when  the  dia- 
phragm i-  fastened  to  the  tube  the  wall  of  the  cone  will  radiate  from 

t  he    f(  iell-    point  . 

.1  <////<,/•  ..    Radiating    Diaphragm  for    Attachment   to    Tube   Stand. — A 


THE    X-KAY 


827 


I'ii;.  ~>-4. — Author's  radiating  diaphragm  attaohod  to  tul>o  stand. 

radiatinu;  cellular  diaphragm  invented  by  the  author  is  for  attachment 
io  the  tube  stand  and  can  be  used  with  a  tube  of  any  size  or  shape. 


MEDICAL    KLKITKICITY    AND    KONTCKN     KAYS 

The  conical  portion  is  riveted  or  otherwise1  fastened  to  a  flat  sheet  of 
rigid  material  transparent  to  the  .r-ray,  such  as  aluminum.  The  latter 
has  a  suitable  rim  corresponding  to  that  of  other  diaphragms  by  means 
of  which  it  may  be  quickly  attached  to  the  tube  stand  and  always  at 
exactly  the  same  place.  The  different  .r-ray  tubes  have  a  mark,  for 
instance,  upon  the  cathodal  prolongation,  to  indicate  just  where  they 
must  be  placed  in  the  tube  shield  so  that  the  focus  spot  on  the  anticathode 
will  be  at  the  imaginary  apex  of  the  hollow  cone.  This  position  of  the 
.r-ray  tube  i-  usually  the  same  as  to  height  and  laterally,  but  varies 
slightly  in  the  long  direction  and  must  be  determined  experimentally 
for  each  tube  before  one  attempts  to  use  it  for  a  picture.  The  appara- 
tus is  only  required  for  a  gas-filled  .r-ray  tube,  not  for  the  (,'oolidge 
tube. 

(".XYN  i if  tin  Author'*  Radiating  Cellular  Diaphragm  Xear  or  Atlochnl 
In  tin  .r-Run  Tuht  .- —As  far  as  concerns  the  radiation  from  the  tube  it 
gives  the  advantage  of  a  small  diaphragm  without  reducing  the  field 
depicted.  Hut  it  has  no  effect  upon  secondary  rays  arising  in  the  tissues 
of  the  body:  and  for  pictures  through  the  trunk,  to  show  foreign  bodies  or 
calculi,  it  i-  inferior  to  the  Bucky  diaphragm.  Without  this  accessory  it 
makes  full  si/ed  plates  of  the  extremities,  the  head,  the  chest,  and  of  the 
stomach  and  intestines,  which  are  better  than  those  made  with  a  plain 
ua-- filled  tube. 

B/irL'//'*  Ra<liali  n(j  Cellular  Scrce/i  Plan  d  Bi  lu-a  »  patient  and  Plate. — 
This  is  an  apparatus  invented  by  Bucky  embodying  the  principles  of 
the  radiating  cellular  diaphragm  described  in  the  first  (1910)  edition  of 
thi-  book  and  Bucky's  principle.  It  is  placed  between  the  patient  and 
the  plate  or  fluorescent  screen  and  consists  of  many  metal  cells  much 
longer  than  their  cross-section,  open  at  each  end.  The  cell  walls  are 
all  so  arranged  that  they  cast  only  linear  shadows  when  the  anticathode 
i-  placed  at  the  proper  point,  say  25  inches,  in  front  of  the  middle  of  the 
apparatus. 

There  is  no  effect  upon  direct  rays  from  the  anticathode  except  to 
cast  clear  shadows  of  the  cell  walls. 

There  i-  some  slight  effect  in  cutting  off  the  secondary  rays  which 
ari-e  from  the  gla-.-  wall  of  the  bulb  of  a  gas-filled  rube,  but  which 
are  neirliinble  in  the  Coolidge  tube. 

There  is  a  very  important  effect  in  cutting  off  secondary  x-rays 
a.'i-intr  in  the  tissue-  of  the  human  body  and  radiating  in  every  direc- 
tion. The  author's  experiments  -how  that  fully  one-half  the  photo- 
graphic effect  upon  the  plate  is  ordinarily  due  to  these  rays.  They  per- 
form no  u-eful  function,  as  they  reach  any  particular  part  of  the  plate 
from  every  direction  instead  of  directly  through  the  portion  of  the  sub- 
ject who-c  -hadow  -hould  be  cast  upon  the  plate  at  that  point.  The  de- 
-irable  ,-hadow  i-  ordinarily  blurred  by  these  rays.  The  cell  walls  ob- 
-truct  all  tho-e  ray-  which  would  reach  any  particular  ',-inch  square  of 
-:."  plate  except  tho-e  that  pa-s  through  the  cell  itself.  The  extent 
to  which  the  [date  i-  ordinarily  affected  by  purely  disturbing  rays  aris- 
ini:  in  the  li--ue-  i-  -hown  by  the  fact  that  the  exposure  with  thi-  screen 
lie  twice  a-  \<>\\<j;  a-  without  it  to  secure  equal  density.  A  wonder- 
1  nl  1 1  em  i  ni -t  rat  ion  of  t  he  quant  it  y  of  t  lie-e  di-t  urbini:  rays  is  produced  by 
j  a  lead  cylinder  '2  inche-  in  diameter  and  '.}  inches  long:  one  open 
•  •iid  beinu;  airain-t  the  plate  and  the  other  against  t  he  patient's  abdomen. 
An  ./•-:•-.  '  .••  u-ed  without  any  diaphragm.  The  plate  is  only 


TFIK    X-KAV 


829 


half  as  dense  inside1  the  cylinder  which  protects  it  from  rays  which  reach 
other  ix>rtions  of  the  plate  from  every  part  of  the  patient  exposed  to  the 
x-ray. 

Secondary  rays  arising  from  the  partitions  themselves  produce  an 
effect  upon  the  plate  looking  like  a  reflection.  This  effect  must  he 
prevented  by  having  the  plate  about  1  inch  from  the  screen. 

Moriufi  Bucky  Diaphragm. — This  is  placed  between  the  patient  and 
the  plate.  Primarily  for  the  suppression  of  secondary  rays  arising  in 
the  tissues  of  the  patient,  it  also  sufficiently  obstructs  secondary  rays 
from  the  glass  wall  of  the  .r-ray  tube.  It  is  a  substitute  for  all  kinds  of 
diaphragms  in  the  .r-ray  tube  or  between  the  x-ray  tube  and  the  patient. 
And  it  is  a  very  great  improvement  because  the  pictures  may  be  14  x  17 
inches,  and 'as  clear  throughout  as  a  small  radiograph  made  with  a  small 
diaphragm.  And  very  thorough  tests  by  the  author  have  convinced 
him  that  it  is  superior  to  filters  of  any  material  or  thickness  between 
the  patient  and  the  plate.  Originally  comprising  a  collection  of  cells, 


Fit 


-Moving  Bucky  diaphragm  (Viotor  .r-Ray  Corporation). 


it  has  been  simplified  and  rendered  practicable  by  making  it  in  the  form 
of  a  grid  with  parallel  partitions,  without  cross  partitions,  thus  having 
slits  instead  of  holes.  In  the  form  shown  in  Fig.  525  the  grid  is  trough 
shaped,  forming  part  of  a  hollow  cylinder  25.^  inches  in  diameter;  the 
partitions  are  about  -J  inch  apart  and  between  them  are  strips  of  wood 
holding  them  in  place  at  just  the  proper  angle.  When  the  .r-ray  tube  is 
in  correct  position  the  partitions  cast  only  linear  shadows,  as  in  Fig. 
52(w/.  made  with  the  grid  stationary.  These  shadows  become  almost  or 
entirely  invisible,  as  in  Fig.  520  b,  if  the  radiograph  is  made1  while  the 
grid  is  moving  laterally  but  like  a  pendulum,  so  that  all  the  slots  continue 
to  face  the  .r-ray  tube  and  to  be  equally  distant  from  the  anticathode. 
The  patient  rests  upon  a  stationary  transparent  cover  above  the  moving 
grid  and  the  plate  is  stationary  under  the  latter. 

Ti:cfittir  irifh  the  Moritig  Buck;/  ])/<iphr<i(jni.—  It  is  not  required  for 
the  hand  or  the  toes  and  metatarsus  where  <i5  kilovolts  (4-inch  spark 
between  points)  gives  all  the  penetration  and  contrast  desired  and  where 
even  a  much  higher  voltage  would  show  lit  t  le  or  no  evidence  of  secondary 
radiation.  For  the  elbow,  ankle,  and  knee  with  the  Bucky  diaphragm 
1)5  k.v.,  4-inch  spark  between  points,  ill)  ma.,  dupliti/ed  film,  two  in- 
tensifying screens,  the  exposure  should  be  about  \\  second:  or  with  SO 


S30 


MEDICAL    KLK(  THIC1TY    AND    KONTCKN    KAYS 


k.v.,  5-inch  spark.  SO  ma.,  1  second;  or  with  IK)  k.v.,  (i-inch  spark,  10  ma., 
2  seconds.  For  the  shoulder  90  k.v.,  10  ma.,  4  seconds.  For  the  hip 
ill)  k.v.,  10  ma.,  10  seconds.  For  the  abdomen  empty,  prone,  (>5  k.v., 
'M)  ma.,  11  seconds  for  instance;  for  gall-bladder,  gall-stones,  or  kidney 
and  renal  calculi:  or  SO  k.v.,  SO  ma.,  7\  seconds  or  90  k.v.,  10  ma., 
12  seconds  for  spine,  hips,  front  part  of  pelvis.  Abdomen  supine  with 
compression  li.">  k.v.,  SO  ma.,  S  seconds,  for  kidney,  bladder,  and  ureter; 
SO  k.v.,  SO  ma.,  ">  seconds,  or  90  k.v.,  10  ma..  10  seconds  for  the  spine, 
sacrum,  and  coccyx,  using  the  author's  graduated  filter  to  reduce  the 


Hiiflioirriiph  nf  rippr-ndix   forty-cijnii    hours   nflcr   li.'irium  meal.     Rucky  dui- 


inten-i'\'  ;it  llic  u';ii~t  and  so  to  secure  sufficient  ettect  at  the  kidney  and 
coccyx  lc\d-  \\itlioiit  overe\po>ure  in  the  middle.  I''or  a  lateral  view 
of  the  spine  90  k.v..  10  ma.,  20  seconds.  For  the  chest  the  standard 
c\po-ure,  but  -ay  about  ">0  per  cent,  more  than  the  usual  time.  l-'or 
the  head,  atiteri ipo-terior,  90  k.v.,  10  ma..  12  seconds;  lateral,  7  sec- 
ond-. 

/)'"'•/•'/  I)  ii />/: riii/n/ .  S/titioiHirii.  (i*  (i  Loi'nl i -_i  r  fur  I''<>ri'ii/n  liuilicx.—  It 
i-  the  author"-  -unLre-tion  that  without  chanirinir  the  po-ition  of  the 
patient  and  u-in1^  either  the  -ame  or  a  ditVerent  plate,  the  tube  may  lie 
moved  2',  inchc-  lateralh'  and  a  secon«l  picture  be  made.  The  marks 
of  the  LTid  Imiii  an  easy  wav  of  .-eein^  the  amount  ot  di.-placement  of 


THE    X-RAY 


831 


the  imago  of  the  foreign  body  compared  with  a  stationary  lead  mark  on 
the  surface  of  the  body,  and  from  this  the  distance  from  the  foreign  body 
to  the  surface  may  be  calculated. 

Stereoscopic  picture*  are  also  made  with  the  Bucky  diaphragm. 
The  first  position  of  the  anticathode  should  be  U  inches  to  one  side  and 
the  second  1.*  inches  to  the  other  side  of  the  center  at  which  it  would 
normally  be  placed. 

Development  is  decidedly  different.  The  bones  and  other  very  dense 
objects,  such  as  the  barium  meal  or  other  foreign  bodies,  cast  nearly 
complete  shadows  with  a  normal  exposure.  The  Bucky  diaphragm  cuts 


r 


Fiji.  olMih. — Radiograph  of  frontal  sinus  with  moving  Bucky  diaphragm. 

out  t  lie  secondary  rays  which  ordinarily  darken  up  t  he  lihn  in  the  shadow 
of  the  bones.  The  image,  therefore,  is  never  lost .  the  film  or  plate  usually 
does  not  have  to  become  black  all  over.  It  is  only  necessary  to  carry 
development  to  the  stage  at  which  the  bones  have  become  sufficiently 
dark  gray  to  show  details.  The  ordinary  photographer  would  call  it 
bringing  out  detail  in  the  shadow-.  And  really  it  is  much  more  like 
the  development  of  a  photograph  than  of  the  usual  radiograph  ol  any 
thick  port  ion  of  t  he  body. 

The  <ir«it<  *t  mini  t//d</i,  <>f  th<  Bnc'i:/i  (linphriiyni  is  in  radiography  of  the 
hip  in  very  -lout  persons  and  in  lateral  radiography  of  the  spine. 

Filter  Between  the  Patient  and  tin  1'lntf .-    This  accomplishes  the  same 


832 


MEDICAL    ELECTRICITY    AND    RONTdKN    RAYS 


purpose  as  the  Bucky  diaphragm,  but  less  perfectly.  The  author  recom- 
mends it  (in  the  absence  of  a  Bucky  diaphragm)  for  every  thick  part  of 
the  hotly  where  the  necessity  for  a  large  picture  makes  a  small  diaphragm 
unsuitable  and  where  the  greatly  increased  time  of  exposure  is  not 
objectionable.  I'sing  .'-cm.  or  1-inch  aluminum,  A.  W.  Crane1  uses 
an  intensifying  screen.  24-inch  distance.  3*-  to  4-inch  spark.  3~>  to  40  ma., 
and  an  exposure  of  one  second  per  3  cm.  (1;  inch)  of  tissue.  The 
author's  own  filters  arc  1.  '2,  or  3  thicknesses  of  roofer's  tin.  With  one 
thickness.  (I')  k.v.  and  twice  the  usual  time  (with  same  number  of  k.v. 
and  nia.1;  with  two  thicknesses  90  k.v.  and  three  times  the  usual  time; 
and  with  three  thicknesses  '.)()  k.v.  and  (>  times  the  usual  time.  An 
example  with  three  thicknesses  of  tin  would  be  '.)()  k.v.,  10  ma.,  abdomen 
prone,  23  inches  distance,  duplitized  film,  two  intensifying  screens. 


I  '•_-.  :  _,.      Heliograph*   of   dollar  and   penny.  <hu\viiiir   secondary-  rays:    A.   Dollar  ."> 

:  nt  i.-at  hode.  it-    -hadow  very  t'aint     because    -eenndar'     ray    iroui  the  ./"-ray 

•     i-  -paer   liehind    it    and    -how  a   i-li'ar   ima^e    ol    the    penny,    whieh    i-    elo-e  to 

II    dollar    i-l  o-i     to  t  he    plate    and    fa-tin:i    a   <  len-i.   -  i,:e :  •  A    in  which  the  penny 

•  h.        \   and    11  made  al    the  -aiiie  exposure. 

thirty  ~econd<.  Thi<  u'i\'e<  ;i  picture  \\ith  \'ery  much  better  contrast 
than  ;i  very  much  shorter  exposui'e.  -i\  seconds,  without  anv  tin  filUT. 
Tlie  picture  is  even  better  than  one  without  a  filter,  but  with  (>5  k.v., 
which  <iive-  the  be-t  unaided  picture-. 

I  nine    nj    iJinphrtif/mx    nn<l    Filler*    in    JinditKjrapliy. — Radiographs 
through    thick    portion-   of   the    body  often    show  the   evidence  of  suffi- 
cient   density  of   r-ray   effect    upon    the    plate   to    produce  a    picture  if 
then     were  only    also   contrast    and    detail.      These   are   lacking  largelv 
b»-c.-i  .-    of    the  -ec(,[|i|ar\r  ray-   which  ari.-e  in   the   tissues    of  the   body; 
darmful    etiect     of    these    secondary    ray-    upon    the    quality 
'•   picture   may   be   very  much   reduced   by  diaphragms  and  filters, 
which   cut    out    the   area    of   tissue  exposed,      This   i-   re.-dly   one  of  the 
mo-'  inij)oi  '  ict-  in  I'ontgenolotiy. 

:   \ni'  r    .Jour.  I  ;-!it  L"-ii')l'»Lrv,  vol.  v,  No.  'i,  .June.   l()ls,  p,  :]()S. 


11  IK    X-KAY 

The  extra  rays  from  the  x-ray  tube  do  not  appear  to  have  great 
power,  hut  they  give  origin  to  secondary  rays  in  the  tissues  \vhicli  differ 
in  no  respect  from  the  secondary  rays  originating  in  the  tissues  under 
the  influence  of  the  direct  focus  rays. 

Diaphragms  and  cylinders,  by  cutting  off  most  of  the  extra  rays  from 
the  tube,  very  greatly  reduce  the  blurring  of  the  image  due  to  secondary 
rays  arising  in  the  tissues. 

The  objection  that  a  shield  of  any  kind  surrounding  the  x-ray  tube 
gives  rise  to  secondary  currents  and  an  electrostatic  condition  tending 
to  cause  rapid  hardening  of  the  tube  does  not  prove  to  be  well  founded. 
The  author  uses  the  Kipperger  shield  constantly  for  therapy  or  radiog- 
raphy and  experiences  no  difficulty  from  this  source. 

Any  opaque  box,  used  to  contain  the  tube  and  protect  the  operator 
from  the  deleterious  effect  of  the  x-ray,  must  be  provided  with  means 
for  connecting  both  the  anticathode  and  the  accessory  anode,  or  either 
one  separately,  with  the  positive  pole  of  the  induction-coil;  and  for 
connecting  the  cathode  with  the  negative  pole  of  the  coil. 

The  Influence  of  Tissue  through  Which  the  Rays  Pass. — Kvery 
substance  impinged  upon  by  the  .r-ray,  whether  transparent  to  it  or 
not,  diffuses  a  certain  amount  of  radiance  in  all  directions,  and  the 
tissues  of  the  body  have  in  this  way  a  certain  radiance  of  their  own. 
This  is  one  element  in  the  production  of  an  indistinctness  in  the  image 
of  parts  of  the  body  at  a  distance  from  the  plate;  and  then1  is  no  remedy 
for  this  particular  defect.  On  account  of  this  fluorescence  of  the  body 
it  is  a  wise  precaution  to  have  the  patient  remain  motionless  for  a  few 
seconds  after  the  x-ray  is  turned  off  before  removing  the  plate. 

After  all  that  has  gone  before,  it  is  easy  to  understand  that  the 
portion  of  chief  interest  in  ('very  picture  should  be  brought  as  close1  to 
the  plate  as  is  practicable.  This  is  in  order  to  secure  the  clearest 
possible  picture  of  the  object,  but  the  rule  is  applied  with  discretion. 
In  taking  a  picture  to  show  a  portion  of  the  brass  shell  of  a  cartridge 
which  had  been  in  the  calf  of  the  leg  for  four  months,  our  purpose 
would  be  more  to  determine  how  deeply  it  was  embedded  in  the 
flesh  than  to  get  a  clear  image  of  the  fragment.  Consequently,  the 
picture  would  be  taken  in  profile  instead  of  in  a  direction  which  would 
bring  the  fragment  some  inches  nearer  the  plate.  The  result  is  a 
more  useful  but  less  beautiful  picture. 

Again,  at  a  distance  to  one  side  of  the  direct  line  the  image  would 
appeal1  longer  than  natural  in  that  particular  direction,  while  its  trans- 
verse measurement  might  be  about  natural.  This  is  analogous  to  the 
lengthened  shadows  cast  by  the  setting  sun.  The  distance1  must,  of 
course1,  be1  so  great  that  with  the  requisite  strength  and  duration  of 
application  there'  shall  not  be1  the'  slightest  elanger  of  an  x-ray  burn. 
So  in  taking  a  picture1  through  the  entire  thickness  of  the1  body  the 
distance  from  the  tube'  to  the'  plate  must  be  correspondingly  greater 
than  in  radiographing  the  hand.  With  the  author's  board  compressor 
the  thickness  of  the1  body  is  reduced  '2  or  o  inches,  and  the  tube  may  be1 
brought  that  much  nearer  the  plate  and  still  be1  at  the  same  distance 
from  the  surface1  of  the  body,  so  that.  gviieTally,  the  '22-inch  distance 
from  the  plate  works  we'll  in  this  case. 

The1  degree  of  vacuum  in  the  tube  is  a  matter  of  prime  importance. 
[•"or  the1  majority  of  cases  it  should  be  so  low  t  hat  t  he  x-ray  will  penet  rate 
but  one  to  five-  layers  of  lead  foil  in  the  author's  fluorometer,  100  s<|uare 
53 


So4  MKDle'AL    KI.Ke'TKle  ITY    AND    KONTCKN    KAYS 

inches  weighing  an  ounce;  and  that  the  resistance'  of  the  tube  is  not 
sufficient  to  back  up  a  spark  of  '2  inches.  A  tube  in  which  the  vacuum 
is  altogether  too  high  is  sometimes  spoken  of  as  a  hard  lube  and  it  is 
one  in  which  the  partial  vacuum  in  the  tube  is  too  nearly  a  complete 
vacuum.  It  contains  too  little  gas  or  air.  Such  a  condition  produces 
snapping  and  sparking  about  t  he  electrodes  of  t  he  t  ube.  and  if  too  st  rong 
a  current  is  turned  on  the  tube  may  be  punctured.  This  happens  by 
a  spark  bursting  through  the  glass  close  to  the  cathode  and  leaping 
across  the  air  outside  the  tube  to  the  entrance1  of  the1  positive  wire1  at 
the  other  end  of  the  tube.  The  sparking  and  possible-  puncturing  are1 
due  to  the  great  resistance  to  the1  passage-  of  the  current  acmss  the' 
space  bet  ween  t  he  cat  hode  and  the-  anode  in  1  he  unduly  rare-He -d  gas  in  t  he- 
mix-.  Another  effect  from  such  a  lube-  is  the-  backing  up  of  a  long 
spark.  The  wires  from  the  two  poles  of  the  secondary  coil  pass  to  the 
two  poles  of  the-  tube  and  all  the  current  is  expected  to  pass  through 
the  tube,  but  if  the  resistance  in  the- lube-  is  greater  than  the  resistance 
in  t  he  air-space1  bet  ween  t  he  t  wo  pole's  of  t  he  coil,  the  current,  erf  cemrse, 
will  take  the  path  e>f  least  resistance  and  if  strong  e-nough  will  spark 
across  between  the  two  pole's  of  the  e-oil.  In  every  .r-ray  outfit  movable 
metallic  rods  should  be  attached  to  each  pole-  of  the-  coil,  and  by  turning 
these  toward  each  other  we  can  determine  the1  distance  across  which  a 
spark  will  pass  between  the  two  pole-s  e>f  the  coil.  Two  factors  e'nter 
into  the  production  of  this  distance:  one  is  1  he  strength  erf  the1  current, 
and  the  other  is  the  resistance  to  the  passage  of  the  current  through  the1 
lube.  With  a  ve-ry  weak  current,  of  course,  we  cemld  not  get  a  long 
spark  across  the  space  between  the  pe>]es  of  the  coil  even  if  the  resist- 
ance in  the  tube  were-  very  great,  or  if  the-  tube  were  disconnected  from 
the  coil  entirely.  In  the  hitler  case,  of  course,  the1  only  path  ope1]!  to 
the  current  is  acre>ss  the  space-  betwe-e-n  the  poles  of  the-  coil.  This 
factor,  the  xtrcn</tfi  of  the  rnrnnt.  is  adjusted  in  the-  simplest  manner, 
just  turning  the  rheostat  up  until  the-  ampe'remete-r  shows  that  the 
necessary  i>  to  0.  or  !),  or,  in  some-  rases,  l.~>  and  e've-n  o()  ampere's  are'  pass- 
ing through  the  primary  e-enl. 

The  other  factor  is  the  resistance  in  tin-  tnhi  a;:d  this  is  measured  by 
turning  on  a  standard  strength  of  current,  say  0  amperes,  ami  approxi- 
mating the  points  connected  with  the  two  poles  of  the  coil  until  a  spark 
passes  between  them.  If  ('»  inches  is  the  srivatest  distance  at  which 
thi~  di -charge  will  take  place',  t  he  t  ube  is  said  to  back  up  a  (i-inch  spark, 
or  10  have-  a  resistance  equal  te>  a  0-inch  parallel  spark-gap.  A  tube 
with  a  resistance1  of  (>  or  7  ine-hes  we>uld  be  too  high  fe>r  most  kinels 
erf  rudiographic  work.  Usually  such  a  high  vacuum  and  consequent 
high  re-i-tance  imply  great  penetration  by  the  ray,  and  in  some  cases 
thi-  i-  desirable1,  as  in  radiographing  the-  roots  of  leeth,  showing  the 
teeth  right  through  the1  jaw,  and  even  the  pulp  canals  in  the1  re>ots  erf 
1  lie  teeth.  Still  even  here1  a  moderately  low  vacuum  is  erfte-n  better, 
a-  it  ti'ives  so  much  belter  contrast. 

\\ith  an  induction-coil  the  spin!  re-meter,  for  ae-tually  testing  the 
leniitli  of  spark  the  tube  will  back  up  is  necessitated  bv  the-  pnsene'c  erf 
tin-  inverse  discharge,  which,  while  usually  eliminated,  may  occasiemally 
invalidate1  t  he  miHiampere  reading  a-  a  criterion  of  t  he'  degree  of  vacuum 
m  the  r-ray  tube.  An  induction  coil  is  very  seldom  pmvieled  with  a 
volt  met  cr. 

With  a  static  machine  the   voltmeter  is   a    useful    gage,   providing  a 


PLATH 


THE  .r-HAY  x:;5 


standard  series  gap  is  used  and  the  usual  power  turned  on  and  the 
machine  giving  its  accustomed  output.  The  spint  remeter  is  not  espe- 
cially suitable  for  use  with  the  static  machine. 

\Vitfi  (in  unfluctuating  (/cncralor  no  spintremeter  is  required,  as  the 
resistance  of  the  tube  is  shown  at  once  l>y  the  consideration  of  the  volts 
hacked  up  and  the  nuniher  of  milliamperes  transmitted.  "With  a  gas- 
tilled  tuhe  this  reading,  and  the  necessary  regulation  to  make  it  right, 
had  hetter  he  made  with  low-current  values,  which  do  not  overheat 
the  tuhe  and  act  slowly  enough  to  permit  of  accuracy.  It  will  usually 
he  found  that  10  kilovolts  and  5  miliiamperes  at  preliminary  regulation 
indicate  a  decree  of  vacuum  suitahle  for  many  Kontgen-ray  ])urposes. 
Turning  on  more  power  the  current  values  will  probably  become  (>2 
kilovolts  and  25  ma.,  and  with  a  "Teat  deal  more  power  {)()  kilovolts 
and  about  50  ma.  The  (  'oolidge  tube  technic  is  given  on  page  779. 

}\'ilh  a  transformer  also  the  spintremeter  may  be  dispensed  with 
for  daily  use,  hut  it  is  essential  for  testing  the  accuracy  of  the  voltmeter. 
The  latter  is  practically  indispensable,  hut  with  great  familiarity  with 
the  apparatus  one  may  get  along  without  the  spintremeter  and  the 
voltmeter.  The  number  of  miliiamperes  transmitted  by  the  .r-ray 
tube,  with  a  given  ratio  of  transformation  and  adjustment  of  rheostat 
with  a  given  strength  of  primary  cm-rent,  are  a  sufficient  guide.  As 
an  example,  it  may  be  stated  that  with  rheostat  button  Xo.  11  of  the 
Waite  and  Rartlett  transformer  a  current  of  35  miliiamperes  indicates 
a  comparatively  hard  tube  suitable1  for  making  a  radiograph  of  the  bis- 
muth meal  in  the  stomach  in  about  one-fifth  second  with  an  intensifying 
screen.  Other  buttons  of  the  rheostat  would  send  50  miliiamperes  or 
more  through  a  tube  in  the  same  condition  of  vacuum.  It  would  be 
well  for  everyone  using  a  transformer  outfit  to  determine  once  for  all 
the  adjustment  of  rheostat  and  ratio  of  transformation  for  a  weak 
current  which  will  give1  a  reading  of  one-tenth  the  current  to  be  sent 
through  a  gas-filled  tube1  when  the  usual  radiographic  current  is  turned 
on.  The  weaker  current  may  then  be  used  in  regulating  the  degree 
of  vacuum  in  the  tuhe. 

Another  method  in  which  the  vacuum  in  the  tube  is  estimated  is  by 
determining  the  dct/rcc  of  penetration  of  the  .r-ray  with  about  the  usual 
amount  of  current. 

1.  With  an  excessively  low  vacuum  there  would  be  no  light  visible 
at  all  in  the  fluoroscope. 

'2.  \\ith  what  is  ordinarily  regarded  as  a  very  low  vacuum  the 
fluorescent  screen  in  the  fluoroscope  is  lighted  up.  but  if  the  hand  is 
held  up  in  front  of  it  the  entire  hand  appears  black  and  opaque,  and,  of 
course,  the  bones  cannot  be  seen  Through  the  flesh. 

;•>.  With  the  regular  low  vacuum  the  bones  show  beautifully,  almost 
black,  the  flesh  clearly  defined  both  from  the  much  darker  bones  and 
from  the  brilliant  light  of  the  background. 

1.  \\ith  a  high  vacuum  the  flesh  and  bones  are  almost  equally 
transparent  and  present  very  little  contrast.  Twisting  a  watch  chain 
around  the  hand,  the  links  are  seen  so  clearly  through  the  hones  that 
you  cannot  distinguish  between  those  which  are  behind  the  hand  and 
those  in  front  . 

5.  An  excessively  high  vacuum  shows  some  light  upon  the  screen 
and  a  grayish  outline  of  the  hand  with  very  little  evidence  of  the  bones. 

To  the  experienced  eye  there  is  all  the  difference  in  the  world  between 


S3G  MKD1CAL    KLKCrUKITY    AND    KOXTOKX     HAYS 

the  poor  image  of  the  hand  shown   by  a  tube  which  is  so  excessively 

high  that  it  is  not  giving  out  any  effective  .r-ray  at  all.  and  a  tube  in  the 
contrary  condition  which  is  giving  out  a  flood  of  .r-ray  producing 
brilliant  photochemic  effects,  but  not  pitched  to  the  rate  of  vibration 
requisite  for  good  penetration.  In  the  ease  of  the  tube  which  is 
a  great  deal  too  li!(/fi  the  tube  shows  very  little  luminosity,  it  is  not 
sharply  divided  into  a  dark  and  a  light  hemisphere,  and  the  dark 
portion  is  blotched  over  with  patches  of  greenish  light  moving  like 
a  liquid.  The  resistance  is  high.  "The  iluoroscope  shows  very  little 
.r-ray  and  a  very  poor  but  not  black  image  of  the  hand.  In  such  a 
condition  a  tube  is  worthless,  but  lowering  the  vacuum  will  effect  a 
wonderful  t  ransformat  ion. 

The  milliampercmeter,  which  measures  the  quantity  of  current 
passing  through  the  tube,  shows  a  decided  increase  in  current  when  the 
vacuum  becomes  low.  and  gives  a  useful  warning  of  the  approach  of 
any  great  drop  in  vacuum  during  the  exposure  for  a  radiograph.  The 
same  diminished  resistance  in  the  tube  is  made  evident  by  an  increased 
amperage  in  the  primary  coil.  In  all  these  cases  the  same  amount  of 
electromotive  force  is  behind  the  supply  current  and  diminishing  the 
resistance  in  any  part  of  the  apparatus  increases  the  quantity  passing 
through  every  part  of  it. 

A  tube  that  is  so  loir  as  not  to  give  any  .r-ray  visible  in  the  fluoro- 
scope  seems  to  be  rilled  with  bluish  or  purple  light  (Fig.  444).  There 
may  be  a  blue  streak  extending  from  the  center  of  the  cathode  to  the 
focus  point  on  the  anticathode.  Such  a  tube  may  look  almost  as  if  it 
had  been  punctured.  In  some  extreme  cases  it  is  not  possible  to  raise 
the  vacuum  to  the  .r-ray  producing  point  by  any  means  short  of  sending 
the  tube  to  the  manufacturer  to  be  reexhausted  with  an  air  pump;  and, 
of  course,  this  is  always  necessary  in  case  of  a  puncture.  In  many 
cases,  however,  the  vacuum  has  temporarily  been  reduced  to  too  low 
a  level  bv  irases  generated  from  heating  the  metal  parts  by  too  strong  or 
too  prolonged  use  or  by  incautious  regulation  of  the  vacuum,  and  when 
the  tube  has  cooled  these  gases  will  be  found  to  have  been  reabsorbed. 

The  ViUnril  oxmo-rctjulutoT  on  certain  .r-ray  tubes  may  be  used  to 
raise  the  degree  of  vacuum  (p.  TtiH,  or  the  vacuum  may  be  raised  by 
turning;  the  current  on  and  off  for  short  period.-,  and  this  may  take  five 
or  ten  minute.-'  work.  Other  tubes  come  up  quite  rapidly  if  a  fairly 
heavy  cm-rent  is  turned  on  for  a  few  minutes,  and  others,  especially  the 
heavy  anode  (  lundelach  tubes,  will  come  up  it  a  reverse  current  is  run 
t  hroii'Ji  i  hem.  With  some  of  the  Miiller  t  ubes  t  here  is  a  raising  device, 
coiisi-t inu  of  a  side  tube  communicating  with  the  mam  bulb  and  con- 
taining a  spiral  of  platinum  wire;  the  positive  wire  may  be  connected 
with  tin-  ii  i. -tead  of  with  its  regular  attachment .  t  he  negat  ive  wire  being 

-     normal  position:  and  the  normal  current  turned  on.      The  current 
o  iLih   the  platinum  spiral  causes  absorption  of  gas  to  take 
umably   i>v   throwing   off    molecule-    of    meial    which   absorb 
md  in  that   way  the  vacuum  is  raised  in  a  verv  short. 
irraimeinent    for    raising    the  vacuum  of  a  tube  is  not. 
e--arv.      The  vacuum  inevitably 
•    i-    used,  and  each  t  line  it    i-    use 
•ei  lucin^   it    to   t  he   propel'  i  legl'ee. 

fur  .r-l-fini  7'///>r.»'.— Air  is  forced  bv 


THE    X-RAY 


837 


interior  of  the  x-ray  tube  by  a  layer  of  unglazed  and  consequently 
porous  pottery.  Normally  this  partition  is  covered  by  mercury  which 
cannot  pass  through  the  pores.  Air  pressure  pushes  and  depresses  the 
level  of  the  mercury  and  allows  the  air  to  reach  the  porous  partition 
through  which  some  air  is  carried  by  suction  and  lowers  the  degree  of 
vacuum. 

To  Raixc,  the  Vftcnuni  of  an  .r-h'ai/  Tube  Without  a  'Regulator. —  Con- 
nect the  accessory  aluminum  electrode  with  the  cathode  and  use  a  weak 
current.  The  connections  are  shown  in  Fig.  f>'2S.  With  reasonable 
care  it  will  not  be  reduced  too  low,  either  during  the  process  of  regulation 
or  during  the  exposure  for  taking  the  picture.  Hence,  the  vacuum  will 
seldom  require  raising  and  then  only  to  an  extent  which  can  be  produced 
bv  opera:  ing  the  tube'  for  a  minute  or  two.  The  sudden  dropping  of 
the  vacuum  of  a  tube  during  operation  with  a  heavy  current  is  due  to 
overheating  of  the  metallic  parts,  and  liberation  of  molecules  of  gas 
which  had  been  held  in  a  state  of  condensation.  This  state  of  con- 
densation is  of  great  importance  in  the  manufacture  and  manipulation 
of  .r-ray  tubes.  The  material  known  as  spongy  platinum,  the  pure 
metal  precipitated  from  a  solution  of  one  of  its  salts,  will  absorb  and 
hold  condensed  in  its  pores  three  hundred  times  its  own  volume  of 
hydrogen  gas.  This  compression,  of  course,  is  accompanied  by  the 
production  of  heat,  and  one  of  the  apparatus  of  a  chemical  laboratory 
before  the  discovery  of  matches  was  based  upon  this  fact.  Dobereiner's 
lamp  consisted  of  a  bottle  containing  iron  filings  into  which  a  few  drops 
of  sulphuric  acid  were  poured,  the  hydrogen  gas,  which  was  evolved, 
escaped  by  a  glass  tube  at  the  tip  of  which  was  a  bit  of  spongy  platinum. 


Sufficient  heat  was  produced  by  the  condensation  of  the  hydrogen  in 
the  spongy  platinum  to  raise  the  metal  to  a  red  heat  and  set  fire  to  the 
jet  of  gas.  The  flame,  thus  produced,  was  used  for  exactly  the  same 
purposes  that  matches  are  now.  There  is  now  on  the  market  an 
attachment  for  the  self-lighting  of  \Yelsbach  gas-burners,  consisting  of 
1  \vo  little  bells  suspended  over  the  burner.  Kach  bell  contains  a  bit 
ot  spongy  platinum  which  becomes  hot  from  absorption  and  condensa- 
tion ol  gas  and  in  less  than  a  minute  the  gas  ignites. 

hi  using  a  heavy  current,  or  even  a  moderate  one  for  a  prolonged 
exposure,  the  author  has  found  it  verv  advantageous  to  watch  the  tube 


838 


MEDICAL    ELECTRICITY    AND    HoNTOEN     HAYS 


closely  and  to  turn  off  the  current  for  a  while  at  the  approach  of  this 
condition  of  excessive  lowering  of  the  vacuum  from  the  sudden  libera- 
tion of  u'as  by  overheated  metal.  It  is  never  difficult  to  see  that  this 
is  coming.  The  inilliamperemeter  sometimes  registers  an  increased  cur- 
rent from  the  lessened  resistance  in  the  tube,  and  at  other  times  a  sud- 
den drop  to  zero  or  to  an  excessive*  milliamperaiic  in  a  reverse  direction 


.  , 

the  change  in  t  he  current  ,  and  a  blue  or  steel  trray  color  develops  between 
the  cathode  and  the  anticathode.  The  current  is  turned  off  at  this 
sto^e  and  the  tube  allowed  to  cool,  and  the  exposure  can  then  be  con- 
tinued. Of  course  it  is  necessary  that  the  patient  and  all  the  apparatus 
should  remain  absolutely  still.  In  this  way  a  piod  picture  may  often 
be  secured  with  an  exposure  divided,  if  need  be.  into  three  or  more 
portion.-.  If  the  current,  on  the  other  hand,  is  kept  Turned  on  at  the 
same  rate  after  the  vacuum  Takes  a  sudden  drop  the  balance  of  the 
exposure  count.-  for  nothing,  and  if  unduly  p'-olonired  may  injure  the 
patient,  booking  at  a  Tube  in  such  a  condition  as  this  you  may  not 
even  be  able  to  see  the  bones  in  your  hand. 

In  nntl;imj  x-rnij  ////«.  s  it  is  not  by  an}'  means  necessary  that  they 
shall  contain  an}'  particular  sras.  Ordinary  air  seems  as  <rood  as  any- 
thing. though  some  manufacturers  place  a  little  phosphorous  acid 


tl  '  tube  and  vapori/e  it  bv  heat,  and  nth<  rs  use  different   ti'ases. 

'  a   ne\\   /-rav  tube.  <>r  one  \\hirli  has  been  sent   to  have  a 

puii'-i  ,  •  "'paired,  or  ha.-  had    to  be  reexhau-ted  for  any  othei1  rea-on, 

a  CUlTcni  ni   el  •riricity   has   to  be   passed    ihi'oiiii'h    the  tube  |iract  icallv 


THK    .r-UAY 


839 


all  the  time  that  it  is  on  the  pump.  This  is  because  the  simple  applica- 
tion of  an  air  pump  would  not  remove  the  molecules  of  gas  held  in  a 
state  of  absorption  by  all  the  different  metallic  parts  inside  the  tube. 
These  have  to  be  liberated  by  the  action  of  a  current,  and  this  must  be 
passed  through  all  the  different  parts  of  the  tube,  including  the  regula- 
tors, and  it  is  not  unusual  for  the  process  to  take;  one  or  t  \vo  entire  days. 
The  result  is  a  tube  containing  so  few  molecules  of  gas  that  the  vacuum 
will  not  fall  below  the  line  with  ordinary  care.  The  line  has  reference 
to  the  condition  in  which  the  presence  of  .r-ray  is  indicated  by  fluores- 
cence in  one  hemisphere  of  the  tube,  separated  by  a  distinct  equatorial 
line  from  the  dark  hemisphere  (Fig. 520).  Theoppositeconditionisshowu 


in  Fig.  ~)3().  To  prevent  a  brand  new  tube  from  being  blackened  it  has, 
of  course,  been  exhausted  while  only  a  moderate  current  is  turned  on. 
and  may  si  ill  contain  imprisoned  molecules  of  gas  which  may  be  liberated 
the  moment  a  powerful  current  is  turned  on.  !•«  r  this  reason  a  tube 
is  hardly  even1  to  be  used  for  radiography  ur.ti!  ii  has  been  tr<i'nml  by 
u-iiiir  it  several  limes  fot  treatments. 

S<  iisnni inj  ii  (in.^-iilli'i  .r-linii  Tube.-  \Yhen  it  comes  from  the  irlass 
blower  it  u^iially  contains  a  mixture  of  gases,  some  ii"  rt,  but  others 
capable  of  or  already  in  active  combination  with  the  metallic  elec- 
trodes. When  such  a  tube  becomes  h.iated  the  vacuum  lowers  because 
of  the  liberation  of  u;as  from  the  electrodes  and  when  the  tube  cools 
gas  is  absorbed  a-rain  by  the  metal  parts.  As  1  he  process  is  repeated 
more  and  more  i  t'  the  active  pi::  1  tv.  mes  tixed  in  the  deeper  layers  of 


840 


MEDICAL    ELECTRICITY    AM)    KONTCKN    KAYS 


tin*  metal,  leaving  almost  exclusively  the  inert  gas  free  in  the  bulb,  ex- 
cepting in  case  of  overheating.  At  the  factory  during  the  time  that 
the  tube  is  on  the  pump  and  a  current  of  electricity  is  running  through, 
the  tube  is  prevented  from  becoming  blackened  by  two  facts:  first, 
the  current  is  not  very  strong,  and  second,  the  presence  of  the  sec- 
ondary anode  has  a  wonderful  effect  in  preventing  this.  This  bene- 
ficial effect  is  produced  even  when  the  anode  and  anticathode  are 
connected  by  a  wire  passing  between  their  points  outside  the  tube. 

The  blncki  niity  which  always  takes  place  in  an  .r-ray  tube  which  has 
been  used  for  any  length  of  time  is  due  to  metallic  particles  driven  off 
of  the  anticathode  by  the  force  of  the  bombardment  of  molecules  to 
which  it  i^  subjected.  It  impairs  to  some  extent  the  efficiency  oi  the 


tube  and   c;inn<;t    be  entirely   removed  even   by   washing  out    the   bulb 
with  hydrofluoric  acid. 

'•'• "   difien-rii    kinds   of  tl<j>{>»it   occur  on    the   inner  surface   of  an 
>ome    tubes   develop   a   dull    black    oVpo-ii    which    interferes 
'.'•I'll    the   efficiency   of  the   tube;   others    -how   a    purple   dis- 
'•oloration   ui    the   Lrlass   which   docs   not    interfere   with    the  <jiialilv  and 
'In-    ray    produced    bv    the    tube,  but    ,-uch    a    tube,  on    the 

M  a  splendid  one. 

'  >'  '  m::.  the  low(  -1  vaciiui  '.'.  ill  produce  a  brilliant 

•    '  i be  L-  the  be.-i  uiie  for  radiographs  .  and  t  hi-  will,  with  most 
'•orn    [in]    :   to  a    re,-i.~tance  -oine\\  11;,  i    |(.-.-   il,;th  -^  indies  and  to  a 
.'    one  thickne.-.-  of  lead-foil.       Thi.-  would  be  the  best 
\    very  sliuhl  ly  higher  vacitum   would  be  bel  tei1 
lid    one   ot    aboil!    '2  .    inche-    n  -i.- ; ;, ,  ,,•••    would    be 
b      It    •'!    inches    l-e-i-talic*  .       \\  ith    the  powerful 


THE    X-RAY 


841 


current  required  for  pelvic  pictures  even  as  low  a  vacuum  as  this  pro- 
duces ;i  penetration  of  five  or  six  thicknesses  of  lead-foil;  Xo.  5  or  0 
Benoist. 

Tcxtint/  the  Quality  of  the  .r-Rtnj. — The  author  very  strongly  depre- 
cates the  use  of  the  hand  for  test  i /it/  the  quality  of  the  x-ray  from  a  tube. 
Everyone  who  habitually  uses  his  hand  for  this  purpose  will,  sooner  or 
later,  develop  a  painful  and  very  probably  a  disabling  and  disfiguring 
inflammation  of  the  skin  of  the  hand.  A  considerable  number  of 
operators  have  suffered  the  loss  of  fingers  or  hand  from  such  a  cause, 
and  one  experimenter  with  the.  x-ray,  who  was  not  a  physician,  is 
reported  to  have  had  chronic  inflammation  from  this  cause  which 


subsequently  was  the  seat  of  cancer,  which  ultimate!}'  produced  a  fatal 
terminal  ion.  but  we  have  not  learned  whether  there  was  an  hereditary 
predisposition  or  not.  At  all  events  the  x-ray  injury  appears  to  have 
been  an  exciting  cause1  of  the  trouble.  Of  course,  it  is  necessary  for 
the  operator  to  be  thoroughly  familiar  with  the  Huoroseopic  appearance 
of  the  hand  and  all  other  portions  of  the  body,  but  no  part  of  the  living- 
body  should  be  used  for  the  dailv  and  hourly  testing  of  the  x-ray. 

The  author's  own  jluoruwctct'  consists  of  a  thin  board  ineasurimr 
M  by  JL'l  inches  with  a  handle  in  the  middle.  Its  major  portion  is 
covered  by  ./'-ray  metal  to  protect  the  hands  and  face  of  the  operator, 
while  a  strip  about  1  inches  wide  extending  across  one  end  is  covered 
with  tin-foil,  weighing  an  ounce  to  a  hundred  square  inches  and  varviim 


842 


MEDK'AL    KLKCTKHTl'Y    AND    RONTGEN    KAYS 


BenoUt's  improved  radiorhromometor.  The  different  sections,  such  as  e 
clined  toward  the  atiticathode  n.  Kach  circular  iin:i<re  shows  an  outer  /one 
an  inner  disk  ot'  aluminum.  The  shadows  of  neither  overlap,  as  is  the  case 

c 

A 


I 


\  \ 


THK    X-RAY  843 

from  ono  to  ton  thicknesses.  Transversely  aeross  these  different  layers 
extends  a  strip  of  heavy  :r-ray  metal  U  inches  wide  with  a  large  num- 
ber of  perforations  at  irregular  intervals.  In  using  this  for  testing 
the  vacuum  in  a  tube  the  x-ray  metal  and  tin-foil  completely  protect 
the  hands  and  face  from  the  x-ray.  The  fluorometer  is  held  in  front 
of  the  tube  by  one  hand,  while  in  the  other  the  fiuoroscope  is  held  be- 
tween the  fluorometer  and  the  operator.  Looking  into  the  dark  box  of 
the  fiuoroscope  one  can  at  once1  judge  of  the  brillance  of  the  light  by  the 
appearance  of  the  screen  where  it  projects  beyond  the  fluorometer,  and 
the  degree  of  penetration  is  determined  by  noting  the  number  of  sec- 
tions of  the  fluorometer  through  which  the  light  passes  and  through 
which  the  perforations  in  the  x-ray  metal  can  be  seen  distinctly. 

The  number  of  thicknesses  of  tin-foil  through  which  the  perforations 
in  the  heavy  x-ray  metal  are  visible  is  the  number  by  which  the  degree 
of  vacuum  is  designated.  This  is  No.  10  in  tig.  532  and  No.  4  in  Fig. 
533.  I  nder  the  usual  working  conditions  the  number  of  inches  of 
resistance  is  about  half  the  penetration  number  indicated  by  my  fluor- 
ometer. 

In  BenoixfH  radiochromometer  (Fig.  530)  the  degree1  of  vacuum  in 
the  tube  is  indicated  bv  the  thickness  of  aluminum  which  the  ravs  will 


penetrate.  There  is  a  central  disk  of  silver,  0.11  mm.  thick,  surrounded 
by  sectors  of  aluminum  numbered  from  1  to  12  according  to  their  differ- 
ent thicknesses  in  millimeters.  'When  the  aluminum  section  5  milli- 
meters thick  casts  the  same  depth  of  shadow  on  the  fiuoroscope  screen 
as  the  silver  disk,  the  tube  is  said  to  be  giving  out  No.  5  rays  and  is  a 
tube  of  medium  pent1!  rat  ion.  A  hard  tube,  on  the  contrary,  gives  out 
Xo.  7  or  8  rays.  It  was  No.  3  in  Fig.  537. 

In  Walter'*  radiometer  there  is  mounted  on  wood  a  thick  lead  disk 
with  eight  holes,  which  are  covered  by  sheets  of  platinum,  of  a  thickness 
of  0.005,  0.01,  0.02,  0.04,  O.OS.  O.l'li,  0.32.  O.(i4  mm.,  arranged  zig- 
zag so  that  n;>  two  of  about  the  same  thickness  are  near  each  other. 
With  the  screen  we  see  only  one  lighted  circle  when  there  is  the  lowest 
degree  ot  vacuum  producing  any  .r-ray:  and  with  the  hardest  tube  we 
can  set1  light  in  all  the  circles. 

1  illard  x  rnfliOHclcwnnetcr  is  an  important  instrument  for  measuring 
the  degree  of  penetration.  The  .r-ray  -hint's  through  a  silver  disk  upon 
out1  quadrant  of  an  electrometer  and  through  an  aluminum  disk  upon 
the  other  quadrant.  The  quadrants  arc1  charged  by  a  source1  of  uni- 


S44 


MKD1CAL    KLKCTKICITY     AND    K<">NT<  JKN     HAY; 


form  potential  such  as  the  direct  110-volt  electric-light  circuit.  loniza- 
tion  of  the  air  hy  the  .r-ray  results  in  its  becoming  a  conductor  and 
in  a  reduction  in  the  difference  in  potential  between  the  two  quadrants 
and  a  change  in  their  relative  position  which  produces  movement 
of  the  hand  on  a  dial.  The  latter  part  of  the  apparatus  looks  like 
the  dial  of  a  milliampercmeter  and  is  graduated  in  figures,  which 
indicate  the  same  penetration  as  the  same  numbers  of  the  Benoist 


S.TouseX 


-c;dcs.  The  deviation  is  dependent  ol  the  intensity  or  quantity  ot 
the  .r-ray.  It  depends  upon  the  relative  amount  of  rays  passing 
through  tin1  aluminum  as  compared  with  that  passing  through  the 
<ilver  di-k. 

The  I  leinx-l'a  uer  qualimeter  is  in  effect  a  voltmeter  applied  to 
'he  cathode  terminal  of  an  induction-coil  or  transformer.  The  <irad- 
uation-  correspond  to  different  decrees  of  penetration  in  the  .r-ray 
pro-  lucci  I. 

( '// •'.-•>! />'.-  linlf-niliti  ni<lh<>(l]  measures  the  thickness  of  water  in 
cent  hnetefs  which  reduce-  the  .r-ray  one-half  or  takes  twice  as  lon^ 
'"  pniiluce  tlie  -ame  photoii'raphic  effect  as  if  the  water  were  not 

there. 


T1IK    X-HAY 


S45 


This  method  can  be  applied  by  an  apparatus  which  consists  of  a 
clock-work  rotated  disk  with  opaque  projecting  cogs  exactly  equal  in 
area  to  the  spaces  between  them.  If  this  is  in  motion  during  the  ./--ray 
exposure  the  plate  under  the  cogs  and  spaces  is  uniformly  exposed  one- 


Fig.  538. — Heinz-Bauer 


half  the  time.  Outside  this  area  are  15  stationary  sectors  of  bakelite 
whose  .r-ray  absorption  is  similar  to  that  of  water.  The  thickness  of 
the  bakelite,  in  centimeters,  whose  shadow  equals  the  half-time  exposure 

indicates  the  quality  of  the  .r-ray.      Kays  of   half-value    1    are   reduced 


half  in  strength  by  passing  through  1  cm.  of  bakelite  or  of  water  and  are 
about  equal  to  Xo.  5  Benoist.  Hays  of  half-value  2  are  about  equal  to 
Xo.  0  Benoist. 

i   <>f  Pcinlrutinn. — A  brilliant    radiance  is  a  necessity  for  ever 


Ml)  MKD1CAL    KLK(  TKICITY    AND    RnNTCKN     RAYS 

radiograph.  Inn  the  decree  :if  penetration  is  an  independent  factor  and 
is  varied  to  correspond  with  the  thickness  or  density  of  the  part  to  be. 
radiographed.  The  length  of  -park  which  a  tube  will  back  up  is  a  most 
valuable  indication  of  the  condition  of  the  vacuum  in  the  tube  and  of 
the  penetrating  quality  oi  the  light.  A  complete  change  in  the  degree 
of  vacuum  during  the  expo-life  would,  of  C(»urse.  render  the  remainder 
:>f  the  exposure  u>eless  or  po.-silily  deleterious.  It  is  to  be  guarded 
against  by  watching  the  appearance  of  the  tube  both  with  the  naked 
eye  and  with  the  fluorometer,  as  well  as  the  two  meters  which  show  the 
amount  of  current  pas-ing  through  the  primary  coil  and  the  amount 
passing  through  the  tube  itself. 

Some  t  ubes  become  high  after  t  lie  current  ha.-  been  turned  on  a  little 
time,  and  when  this  is  very  marked  it  is  rather  a  worse  fault  than  the 
other.  A  tube  which  has  a  tendency  to  become  low  by  the  evolution 
of  u'as  may  be  coaxed  along  at  a  uniform  degree  of  vacuum  by  several 
exposures  so  as  to  Lret  the  full  time  with  a  powerful  current.  But 
with  the  other  kind  of  a  tube  you  either  have  to  resign  yourself  to  an 
increasingly  high  vacuum  or  else  stop  and  regulate  the  vacuum  in  the 
tube.  This  may  take  several  minutes  and  the  effect  in  such  a  case  is 
only  momentary.  An  automatic  regulator  (Queen)  may  in  some  cases 
be  set  so  as  to  keep  the  vacuum  from  becoming  too  high. 

'!»  Lon'(  r  tin  I  urn  a  in  in  <i  T  uh(  II  itlioiit  «  Hcf/ulfitoT. — Connect  the 
aluminum  accessory  electrode  to  the  anticathode  and  use  a  strong  cur- 
rent. The  connections  are  shown  in  Fig.  52 S.  B. 

The  vacuum  of  a  tube  which  has  no  regulator  may  be  lowered  by 
heating  the  tube  gradually  with  an  alcohol  lain]),  not.  of  course,  while 
the  current  is  on:  or  the  tube  may  be  boiled  in  oil  for  half  an  hour. 

A  non-regulating  .r-ray  tube  which  has  become  hard  from  exhaustion 
of  the  iraseotis  contents  through  use  may  return  to  its  original  degree  of 
mi  if  it  is  laid  aside  for  a  certain  number  of  days  or  weeks,  or 
the  same  result  may  be  obtained  by  baking  the  tube  in  an  ordinary 
oven  at  a  temperature  of  three  or  four  hundred  degrees  Fahrenheit. 
In  either  case  molecule.-  of  gas  are  liberated  from  the  metallic  parts  of 
the  tube  and  the  deposit  on  its  inner  surface  bv  which  they  had  been 
absorbed. 

The  rcijnlnti ntj  flcrir(-n  for  reducing  the  degree  of  vacuum  form  the 
distinct  ive  features  of  the  < lifferent  types  oi  .r-ray  tubes  and  are  described 
on  '  ;  .  "til  to  "til. 

Different   Results   from  High   and   Low  Tubes. — The  difference 

beT'.veen   a    radiograph  taken  with  a   high   and  one  with  a   low  vacuum 

is  chirflv  that  the  low  vacuum  gives  greater  contra.-t  between  portions 

nu:  different  densities,;  while  the  high  degree  of  vacuum  sometimes 

LMVCS  i  I'-;  ter  i  lefinii  ion. 

\\  itli  a  static  machine  a  tube  is  required  to  have  a  verv  much  higher 
with  a  coil,   but    the  use  of  the  static   machine  in  radiog- 
;-  -•'  insii  len-i  1  in  aiiot  her  sect  ion. 

\\  e  often  hear  the  statement  that  a  picture  can  be  made  in  a  shorter 

time  \\  ;-ji  a  hiL i,  I  han  \\  it  h  a  low  vacuum,  but .  coupled  with  t  his  st  at  e- 

v.  e   ,-  ,;;,;•,  find  indications  that  the  observe)1  does  not  discriminate 

'  he  lack  i  ,i  effect  due  to  t  he  absence  oi  intensity  or  brilliancy  and 

flu    lack  1,1  penetration  due  to  a  low  vacuum  in  its  strict  sense.      A  low 

vac  .  im,  oi  cotir.-e,     -  a  condition   in   which  there  i.-  a  large  amount  of 


THK    J-KAV  847 

gas  in  tho  tuho.     There  must  he  an  appreciable  amount  of  photochemic 

effect  produced  on  a  sensiti/.ed  plate  hy  the  .r-ray  passing  through  a 
portion  of  the  hody  in  a  certain  period  of  time  in  (jrder  to  make  a  picture 
at  all.  In  order  to  make  a  good  picture  the  ./'-ray  must  he  of  such  a 
quality  that  suhstances  of  very  slightly  different  densities  will  arrest 
it  in  a  sufficiently  varying  decree  to  show  the  outline  and  structure  of 
the  various  portions  to  he  depicted.  With  a  high  vacuum  this  selective 
absorption,  to  quote  J)r.  Cole,  is  almost  ahsent.  Kven  with  as  easy 
a  suhject  as  the  hand,  the  contrast  between  the  flesh  and  the  dense 
bones  is  very  slight,  and  in  radiographing  a  small  renal  calculus  of 
low  specific  gravity,  the  shadow  of  the  column  of  tissue  including  the 
calculus  differs  very  slightly  from  the  adjacent  columns.  The  difference 
in  the  density  of  the  two  areas  is  as  slight  as  if  they  were  columns  of 
water  to  one  of  which  a  pinch  of  calcium  salts  had  been  added.  The. 
difference  may  be  shown  by  a  ray  of  the  proper  character,  but  not  by 
one  which  will  penetrate  ten  thicknesses  of  lead-foil  without  appreciable 
absorption.  As  Dr.  ("ednuin  says,  a  radiograph  is  a  chart  of  the  different 
densities  of  the  parts  depicted. 

The  t/iickticxH  and  density  of  the  part  have  a  very  "Teat  bearing  upon 
the  length  of  exposure  and  the  intensity  of  the  radiation  required. 
(ienerally  speaking,  in  order  to  produce  a  good  picture,  the  tube  must 
give  a  powerful  enough  ray  to  enable  us  to  see  nicely  through  the  part 
with  the  fluoroscope.  Almost  everywhere  the  radiograph  will  show 
only  the  same  things  as  the  fluoroscope,  but  show  them  better.  "With 
practice  it  becomes  an  easy  matter  to  judge  of  the  degree  of  vacuum, 
strength  of  current,  length  of  exposure,  and  all  the  other  factors  for  any 
portion  of  the  body  without  making  a  preliminary  fluoroscopic  test. 
The  lungs  are  almost  transparent  and  pictures  of  the  chest  can  be  made 
with  apparatus  hardly  strong  enough  for  a  pelvic  picture.  I  p  to  the 
year  I'.HHi  the  ,r-ray  in  one  of  the  largest  hospitals  in  New  York  was 
produced  by  a  static  machine  with  which  it  required  eight  minutes 
to  take  a  picture  of  the  chest  and  with  which  it  would  have  taken  forty 
minute.-  or  so  for  a  hip-joint.  In  these  days,  of  course,  such  a  length 
of  exposure  would  be  prohibitory.  While  the  weak  radiation  might 
very  well  produce  no  bad  effect  upon  the  patient's  tissues,  the  length 
of  exposure  required  would  occasion  anxiety  on  the  part  of  the  patient, 
who.  of  course,  has  heard  of  .r-ray  burns  and  who  ma}"  have  heard  of 
the  pract  icahility  of  taking  pictures  of  the  hip  in  from  ten  to  one  hundred 
seconds.  The  same  apparatus,  of  course,  will  take  a  picture  of  a  hand 
in  quite  a  reasonable  length  of  time.  Hone  is  very  much  less  trans- 
parent to  the  .r-ray  than  flesh  and  the  teeth  are  still  less  transparent. 
As  we  shall  see  on  another  page  there  is  no  difficulty  at  all  about  making 
a  picture  showing  the  roots  of  the  teeth  right  through  the  jaw-bone,  and 
what  we  consider  a  good  radiograph  shows  even  the  entire  nerve  or 
pulp  canal  in  the  tooth  and  its  roots.  The  greater  the  density  and 
thickness  of  the  part  to  be  penetrated,  the  stronger  the  current  must 
be.  and  within  very  much  narrower  limits,  the  higher  the  vacuum  must 
be.  \arious  tables  have  been  prepared  showing  the  relative  density 
of  different  parts  of  the  body  and  various  other  substances.  It  appears, 
however,  to  be  a  safe  generalization  to  say  that  the  resistance  to  the  pas- 
sage of  the. r-ray  is  greater  for  substances  with  greater  specific  gravity. 
This  leads  to  some  surprising  results.  With  the  fluoroscope  we  can  see 
right  through  a  black  leather  case,  but  the  thin  perfectly  clear  colorless 


MKDK   At.     KI.K<THIdTY     AND     RONTCKN     RAYS 

glass  vials  look  like  so  many  cartridges.  The  chest  in  a  good  radio- 
graph shows  the  nearly  transparent  lungs  and  the  more  opaque  spine, 
ribs  and  heart,  and  lower  down  the  great  dense  mass  of  the  liver.  Below 
that  the  abdominal  contents  are  less  opaque  than  the  liver,  but  much 
more  so  than  the  lungs.  The  uppermost  part  of  the  thigh  is  a  much 
more  opaque  object  than  the  upper  part  of  the  chest. 

The  effect  of  ordinary  light  upon  a  photographic  plate  exposed 
directly  to  it.  not  in  a  camera,  for  a  certain  period  of  time  is  less  the 
further  the  light  is  from  the  plate.  This  decrease  in  photochemic 
effect  is  considerably  greater  than  would  follow  from  the  law  that  the 
illumination  diminishes  in  proportion  to  the  square  of  the  distance. 
The  distances  in  .r-ray  work  do  not  vary  so  much,  however,  as  to  invali- 
date the  law  as  to  the  square  of  the  distance,  but  the  thickness  and 
densitv  of  parts  of  the  body  form  a  most  important  factor  in  the  calcula- 
tion. The  practical  application  of  the  principles  involved  will  be 
considered  when  describing  the  radiography  of  special  parts  of  the 
body. 

The  Position  of  the  Tube. — When  an  .r-ray  tube  of  the  ordinary 
pattern  is  in  operation,  the  tube  is  seen  to  be  divided  into  a  dark  and  an 
illuminated  hemisphere  by  an  oblique  plane,  which  corresponds  closely 
with  the  plane  of  the  anticathode.  Behind  this  plane  there  is  very 
little  .r-ray  to  be  seen  with  the  Huoroscope.  The  statement  is  often 
made  that  the  direction  of  greatest  intensity  of  the  .r-ray  is  in  a.  line 
drawn  perpendicular  to  the  center  of  the  anticathode  and,  hence, 
coinciding  with  the  middle  of  the  illuminated  hemisphere.  Other 
authors  state  that  the  greatest  intensity  is  in  a  line  forming  a  natural 
angle  of  reflection  between  the  cathode  stream  where  it  strikes  the 
anticathode  and  the  .r-ray  originating  there.  According  to  my  own 
observations  on  tubes  of  several  different  patterns,  the  intensity  of  the 
.r-ray  is  the  same  in  every  direction  in  the  lighted  hemisphere'  until  the 
dividing  line  is  almost  reached.  Theoretically,  the  ./--ray  should  be 
equally  diffused  in  every  direction  from  the  point  of  impact  of  the 
cathode  stream  upon  t  he  ant  icat  hode,  and  the  dark  hemisphere  should 
In'  merely  the  shadow  of  the  anticathode.  In  testing  this  matter  the 
lube  has  been  placed  with  its  axis  horizontal  and,  has  been  operated  by 
current.-  ot  different  degrees  of  strength  and  observed  by  means  of  the 
(luoroscope  and  various  test  objects,  like  the  hand  and  a  pin-cushion. 
The  author  has  found  that  for  the  same  strength  of  current  and  the 
same  distance  trom  the  tube,  the  mtensitv  ot  the  .r-ray  was  the  same  in 
every  direction  corresponding  to  the  illuminated  half  of  the  tube.  And 
t  hi-  same  tv-ult  was  obtained  when  t  he  I  ube  was  pi  a  ceil  vert  ica  11  y. 

1'  i-  much  more  convenient,  in  adjusting  the  tube  and  conducting 
cords  .~M  that  there  shall  be  no  danger  ot  the  patient  receiving  a  spark 
tl'om  tin-  curd-  or  the  tips  of  the  tube,  to  place  the  tube  so  as  to  use 
t  he  ra\>  which  come  at  a  ri^ht  angle  to  the  axis  of  the  tube.  So  that, 
a-  a  rule,  the  plate  is  upon  the  table,  the  portion  to  be  radiographed 
rc-t  in'j  upon  !  he  plate,  and  t  lie  .r-ray  t  ube  \\  it  h  its  axis  hori/.ontal  and 
nt  ii-athode  directly  above  the  center  ()f  the  plate.  And,  as  a 
two  conducting  cords,  either  nf  uncovered  spiral  steel 
,-,,,  inch  thick,  or  nf  tlun  l!e\ib]e  insulated 


_ 

wire  wound  on   spring  reel-,  extend  directlv  from  the  pol 
in    ih.-    iwi 


819 

distant  from  the  poles  of  i  he  coil,  and  the  conducting  cords  do  not  rest 
upon  any  part  of  the  tube  stand.  The  special  object  is  to  have  the 
wires  extend  in  such  a  direction  that  they  will  not  be  anywhere  near 
any  pan  of  the  tube  except  the  lips  to  which  they  are  attached.  In 
this  way  the  possibility  of  puncturing  the  tube  is  prevented.  And  this 
arrangement  renders  it  easy  to  avoid  sparking  from  the  wires  to  the 
metal  pans  of  the  tube-holder  or  to  the  regulator  of  the  tub*.  Tube 
stands  are  provided  with  wooden  rods  to  hold  the  conducting  cords 
from  undesirable  contacts  when  this  position  is  impracticable. 

A  lar.u'e  series  of  radiographs  have  been  successfullv  made  with 
tubes  of  different  makes  in  this  position.  It  is  a  curious  fact,  however, 
that  the  greatest  amount  of  heat  develops  along  a  line  drawn  per- 
pendicular to  the  surface  of  the  anticathode,  and  under  certain 
circumstances  some  tube.-  which  are  producing  practically  no  ./'-ray 
will  .mive  an  occasional  distinct  flicker  in  a  direction  decidedly  bevond 
t  lie  angle  of  reflection  of  the  cathode  ray  when  it  st  rikes  1  he  ant  icat  hode. 
This,  1  think,  is  due  to  the  irregular  cathode  ravs  not  being  accurately 
locused  on  the  anticathode.  Some  of  them  pass  beyond  the  anti- 
cathode  and  strike  the  glass  wall  of  the  tube,  giving  origin  to  the 
.c-ray  there. 

The  Strength  of  Current  in  the  Primary  Coil. — This  is  the  great 
factor  in  ivtnilat  ing  the  intensity  of  the  .r-ray  from  a  t  ube.  With  some  coil. - 
or  t  ran.-formers  quite  a  beautiful  .r-ray  may  be  produced  with  as  low  as  :-J 
ampere.- :  while  other  tubes  and  coils  or  transformer.-  are  made  to  stand  a 
primary  current  of  30  or  40  amperes  for  a  short  time.  Other  things  being 
equal,  t  he  heavier  the  primary  current ,  the  shorter  t  he  time  required  and 
the  thicker  the  tissue  through  which  a  succ<  ssful  radiograph  may  be  made. 
A  current  twice  as  strong  will  produce  a  picture  in  about  on"-tenth  as 
long  a  time.  Too  heavy  a  current  for  the  individual  apparatus,  of  course, 
may  burn  out  either  the  primary  or  the  secondary  coil:  the  excessive 
intensity  causing  the  current  to  break  through  the  insulation  separating 
the  different  turns  in  the  coils.  A  hundred  dollars  worth  of  wire  may 
thus  be  ruined  in  a  Hash.  The  fuses  down  in  the  cellar  and  elsewhere 
alonu'  the  feed-wires  are  to  prevent  such  an  accident  and  should  be 
of  -nrh  capacity  as  to  permit  the  passage  of  only  such  a  strength  of 
current  as  may  safely  be  used.  Kven  1  hen  a  too  long-continued  ilow 
of  a  heavy  current  through  the  primary  will  heat  up  the  thin  wire  in 
the  secondary  coil  and  may  break  down  its  insulation.  A  12-inch  coil 
should  stand  a  primary  current  of  !  ID  volts  and  1  •">  amperes  for  a  minute 
at  a  time  without  trouble,  and  this  should  be  lom:'  enough  tor  the  entire 
exposure  tor  any  picture,  and  a  very  much  shorter  time  will  ordinarily 
be  sufficient.  There  are  very  few  tube-  made  which  will  stand  so  heavy 
a  current  for  a  minute  at  a  time.  A  '  lundelach  heavy  anode  tube,  type 
bulb  L't)  inches  in  circumference  and  measuring  '_'•]  inches 
to  tip.  has.  in  my  hand-,  stood  precisely  such  a  test  suc- 
The  majority  of  tubes  will  break  down  under  such  a  strain. 
may  puncture  or  the  anticathode  may  melt,  or  the  vacuum 
to  such  an  extent  that  the  production  of  effective  .r-ray 
other  tubes  may  be  used  with  as  heavy  a  current  as 
termiiteiit  exposure  to  prevent  the  tube  from  becoming 
A  primarv  current  of  ID  amperes  may  be  considered  as 
for  ireneral  radiography  \\ith  a  I'J-incti  coil,  and  am 
er  rat  in^  <  »r  i  iver.  with  a  heavv  am  »de  <  >r  a  v  ; 


MKDK  \i.    KI.KI 'TKierrY    AND    K<>.\T<;I:N    KAYS 

cooling  device,  ought  to  stand  this  long  enough  for  a  picture.  Here 
a^ain.  ho\\ ever,  it'  tin-  time  i.-  more  than  forty  seconds,  most  lubes  will 
produce  a  better  picture  if  the  e.\])osure  is  interni])te(l,  Kven  one  of 
tin-  thin  anode  tubes  may  In-  used  in  this  way  with  such  a  current  ;  and 
the  fact  that  tln-v  contain  a  much  smaller  amount  of  metal  causes  them 
to  maintain  the  .-a me  decree  of  vacuum  better  than  some  ot  the  heavier 
tube-;  still,  the  heavv  anode  tubes  are  preferable  tor  radiography. 
The  weaker  primal'}"  currents  ot  i>  to  (i  amperes  work  very  nicely  with 
an  ^-inch  coil  and  with  tubes  of  25-  to  10-centimeter  rating.  As  stated 
elsewhere.  aii\"  conditions  which  produce  a  good  iluoroscopic  image 
of  the  part  in  <|UesUon  will  produce  a  good  picture,  if  the  plate  has  the 
proper  derive  of  sensitiveness  and  the  exposure  i.-  properly  timed  with 
relat  ion  io  t  he  ot  her  factors. 

(  lenerally  speaking,  the  intensity  of  the  radiance  is  increased  or 
diminished  bv  usinu'  a  stronger  or  a  weaker  current  through  the  primary 
coil,  and  to  a  irreat  extent  the  same  instruments  regulate  both  the 
amperage  and  the  voltage  of  this  current .  The  lid-volt  direct  current 
of  the  electric-light  circuit  passes  through  our  liquid  interrupters  and 
iron  wire  rheostats,  and  enters  the  primary  coil  as  a  current  of  only 
MI  or  (Ml  volts  and  with  a  volume  of  15  to  1*  amperes  for  routine 
work. 

Ri  <l  Hi-lion  of  VoUiKjc. — There  are  several  ways  in  which  the  voltage 
may    be    still    further    reduced    and    the    same    amperage    maintained. 
The  usual  way  is  by  means  of  a  shunt  circuit,  the  electric-light  current 
win-  dividing  and  part  of  the  current  passing  through  a  suitable  resist- 
ance, entirely  separate  and  independent,   the  other  part  of  the  current 
pa.--in:r   through    the   .r-ray    apparatus.      If   we    have    an    amperemeter 
at   the  wall  socket  measuring  the  total  amount   of  current   passing  and 
another  measuring  the  amount    passing  through   the  primary  coil,  the 
difference  between  the  two  will  indicate  the  reduction  in  the  voltage  in 
the  primary  coil,      \\here  a  current   divides  in  this    way    between    two 
path-    the    volume,    or    amperage,    passing    through    each    is    inversely 
proportional  to  the  resistance,  and  the  voltage  in  each  is  directlv  pro- 
portional   to   the   amperage.      Or  a    voltmeter   may   be   placed   upon   the 
ry  circuit,  which  will  indicate  directly  the  number  of  volts  passing 
through  the  primary  coil.      A  voltmeter  ma}"  be  made  in  the  same  way 
a-  a   galvanometer,  but   so  adjusted  that  the  readings  on  the  dial  are  in 
volt.-.      There    an;    two    principal    types    of    (n,//>rrenieterx,   in    one    the 
hand    i-    moved    by   the    various   lengthening  of  a    wire   which   becomes 
.    the  passage  of  currents  ot  different   volumes;  in  the  other  the 
hand  i-  n  ov«-d  bv  t  he  effect  of  a  current  t  hroiiLih  a  wire,  or  a  coil  of  wire, 
h'j  a  magnetic  needle  and  tending  to  r;msc  the  needle  to  a-sume 
a    po-in'on    •;•    ri-jht    angles   to   the  direction   of  the  current.      This   is  a 
•    v  -imple  matter  and  the  readme  is  in  amperes  or  milham- 
'    •          '    mav  be,  regardless  ot  the  volt  n  ire  ot  t  he  current  or  1  he 
'••'  '••      '     '    e  circuit.      The  same  tvpe.-  n|   m.-t  rumeni   sei'\'e  as  volt- 
•  .  in  the  "Taduation  of  the  in-trumeiit  in  volts  it   i- 
re-i-taiice   m    the  circuit    -hall    be  a  constant,  not    a 
With    a    uniform    re.-i-tance    the    amount    of    the 
|  >ro|  >ort  lonal    to    ;  IH  •          '      •       the    amount    of    the 
v,  hat    '  leilect  -  i  h<    hand,  bu'    i'    al.-o  indicates  t  he 
•     •    "ci     •.'.  i  :'';i    drive-    1 1  mi    of   current 

•    i-'ance.      Tin-  gradual  ion.-  upon  amperemeters. 


Tin:  .r-iiAY  851 

and  voltmeters  arc  always  made  by  comparison  with  standard  instru- 
ments. It  would  be  difficult  to  construct  one  on  entirely  theoretic  lines 
and  have  the  graduations  turn  out  exact  ly  accurate. 

Another  apparatus  ior  reducing  the  voltage  of  a  current  for  .r-ray 
purposes  was  published  by  Lallcmont .'  It  consists  of  a  jar  of  dilute  acid 
through  which  the  current  passes  between  two  lead  electrodes.  ( )ne  of 
the  electrodes  is  more  or  less  conical  with  a  cruciform  cross-section,  so 
that  the  deeper  it  is  immersed  in  the  liquid  the  greater  the  surface  of 
contact,  and.  consequently,  the  greater  the  volume  of  current  trans- 
mitted. Fart  of  the  current  passes  through  the  liquid,  so  thai  if  120- 
volt  direct  current  is  shunted  through  dilute  sulphuric  acid,  1°  Beaume, 
the  voltage  is  reduced  to  about  GO. 

Very  many  of  the  operators  in  Europe  use  a  current  of  GO  or  SO  volts 
for  x-ray  work,  obtaining  it  usually  by  means  of  a  shunt-controller.  In 
the  I'nited  States,  however,  most  of  the  .r-ray  coils  are  made  to  use  the 
110-volt  or  even  the  220-volt  currents,  reduced  only  slightly  in  voltage 
by  the  ordinal1}'  resistance  of  the  rheostat  and  interrupter. 

The  regulation  of  volume  of  the  prinian/ current  for  .r-ray  work  varies 
from  o  or  1  up  to  30  or  40  amperes,  according  to  the  nature  of  the  pic- 
ture to  be  made  and  the  character  of  the  tube  and  other  apparatus  em- 
ployed. Two  different  forms  of  rheostat  are  in  very  common  use  for 
regulating  the  amount  of  current  admitted  to  the  apparatus  from  the 
electric-light  circuit.  The  current  in  the  latter,  of  course,  is  perfectly 
enormous,  as  is  easily  discovered  by  short  circuiting  it,  for  example,  by 
touching  the  outlet  and  inlet  wires  with  a  pen-knife  blade.  There  is 
a  blinding  flash  of  light  and  a  piece  of  the  knife  blade  is  actually  burnt 
right  out.  With  any  properly  installed  system  of  wiring  there  are 
fuses  in  the  cellar  and  elsewhere  which  burn  out  when  an  excessive 
current  like  this  is  turned  on  by  accident  or  by  mistake,  and  the  whole 
system  becomes  dead  almost  as  soon  as  the  flash  occurs.  Without 
such  protection  by  fuses  any  electric-light  current  would  be  a  source 
of  the  very  greatest  danger  from  fire,  and  even  with  it  the  very  greatest 
attention  should  be  paid  to  the  proper  insulation  of  the  entire  apparatus 
and  wires.  It  is  important  to  remember  that  the  secondary  current 
is  of  such  high  tension  that  it  will  break  through  practically  any  insula- 
tion, and  that  the  wires  leading  from  the  coil  to  the  tube  must  not  be 
allowed  to  touch  any  other  wires.  If  they  do  there  will  be  a  spark 
and  an  odor  of  burnt  rubber,  anything  inflammable  may  catch  fire,  the 
fuses  all  burn  out.  and  the  current  stops.  The  insulation  of  both  wires 
is  burnt  through  and  then  you  have  a  couple  of  wires  with  permanently 
defective  insulation.  This  last  result  is  not  so  important  in  the  case 
of  the  wires  leading  to  the  tube;  they  are  not  supposed  to  be  fully 
insulated  and,  indeed,  some  of  my  favorite  cords  are  fine  bare  iron 
springs.  And  in  these  cords  the  volume  of  current  is  very  small,  some- 
where around  2  to  10  milliamperes,  from  which  the  danger  of  lire  is  nil. 
Am!  aii'ain.  these  wires  are  only  charged  when  in  actual  use  and  are  then 
nded  in  mid-air  between  the  poles_of  the  coil  and  the  tips  of  the 


possibilities  we  may  compare  n  to  a  water-main  passing  through  a  city 
street,  tapped  here  and  there  liy  small  pipe.-  leading  lo  faucets  m  the 
different  houses.  At  these  faucets  the  p  res.- life  n  >rre.-poli<  Is  to  1  lie 
difference  between  the  level  of  the  faucet  all'i  the  level  of  the  reservoir 

''rom  which  t  he  water  come.-.  The  mulcts  are  small  and  the  amount  of 
water  which  can  escape  l.-  onlv  t  he  amount  \vhich  that  pressure  can  torce 
through  a  hole  of  that  si/.e,  hut  if  \\  e  make  a  larue  break  in  the  main, 
we  will  ha\'e  an  escape  of  water  threat  enough  to  undermine  the  house 
if  it  i-  not  promptlv  checkeil.  The  quantity  of  water  and  the  pressure 
are  ;il\v;i\-s  there,  it  is  oiil\'  that  ordinarily  the  openings  are  so  small  as 
to  present  -uch  friction  or  resistance  that  only  a  stream  of  the  desired 
magnitude  can  escape.  In  the  case  of  the  elect  nc-li^'ht  circuit  there 
i-  enough  volume  of  electricity  in  the  street  mam  to  run  a  number  oi 
la r<ie  motors  and  thousands  of  electric  lights.  The  amount  of  current 
which  will  pas.-  through  any  apparatus  is  determined  l>y  its  resistance 
which  corresponds  to  the  size  of  the  opening  at  the  water-tap  or  faucet. 
Diminish  the  resistance  and  as  heavy  a  current  may  t  >e  obtained  as  is 
desired,  do  away  with  the  resistance  altogether  by  short-circuiting  the 
current,  and  vou  have  done  almost  the  equivalent  ot  making  a  break  m 
the  water-main  and  you  iret  a  perfectly  tremendous  discharge,  but. 
t'ortiiiuiTely.  one  which  is  almost  instantly  cut  ot'f  b\"  the  burning  out  ot 
the  fuses  all  alom:  the  line  from  the  apparatus  to  the  mam.  I'sually 
the  apparatus  itself  will  escape  unharmed,  but.  of  course,  there  is  always 
the  possibility  of  burninji  out  1  he  pnmar\'  or  secondary  coil  and  chanjrin<i 
a  Imndred  dollar-'  wort  h  of  wire  into  1  went  y  or  thirty  pounds  of  copper, 
and.  of  course,  there  should  always  be  mean-  at  hand  for  extinguishing 
anv  slight  conflagrations;  or.  it  is  better  still  not  to  have  wood  or 
drapery  or  carpets  around.  The  onlv  time  that  the  present  author 
ever  had  to  extinguish  a  bla/e  was  in  connection  with  some  absorbent 
c  itton  placeil  m  the  box  containing  a  ('aldwell  liquid  interrupter,  to 
deaden  the  noise.  Thi-  became  ignited  from  the  slight  spark  which 
i'  is  hard  to  obviate  at  the  contact  between  the  lead  electrodes  and  the 
ci  ppi  ier  coin  luct  im:  con  Is. 

The  hea\'iest   current   \\-hich  will  pass  through  a  ('.-.Idwell  interrupter 
>   from   '.i  to    II    amperes;  this  i-   without    anv   rheostat    and  simplv   the 
1  '•'•   [jfesented  bv  tlie  coil    it-ell    aiid    foi1  a    \'ery   ^reat    inan\'  radio- 
nil-  this  -trenuih  of  current   \\-ill  be  found  to  be  ample. 
Rate  and  Character  of  Interruptions.      In  the  Calilm-U  oYSiiunn 
•    .  for  the\-  mad'1  the  invention  independent  lv  and  at  about   t  he 
-  •  •  •  ,•    '   tne.  !  he  priori!  \'  I  t  hmk  belong! IIL:  t  o  <  'a  !'  [wi  '11.  i  he  suppl  v  current 
lie    -ul]  ilmric    acid,    about     one    to    six.       (  )ne    lead 
m   an    inner  beaker  ol    'oiii:h   porcelain   through 
i  ablisli    ci  immunica  t  ion    \\  it  \t    acid  in  t  In-  outer 

'    ol  her  leai  1  elect  n  ule.      h  doc.-  n<  it   mat  ter  which  i- 
-  ne-^at  i  ve,       \\  lien  a  heav1    r-ij  ri'eni   i<  passed  t  hl'oiii:h 
re-i-1  alice   i-       .  .      •       I    t  hi     pin-holes,   where 

or  i-  ver;     -mall.      Tl  •  1 1        id  <  ir  act  ually 

';'--    point-   ai  •        •  lin-holes   and   for  a 

'.••    -•  i    nei  Mon    i-   broken.      The   en  -     in-  to   How   a.ii'a  in 

if   escape-.  some    int  efl'll]  itel'S 

'    •        '  •        I  I  in  e -  a  Hi  1 1 1 1 1 1  e . 

'I     fluid       '          h  i'-li    elect  n  ilv-i-    t  a  kes 
<(  ra  1  i-d    at     !  he 


853 

negative  and  of  oxygen  at  the  positive  electrode.  This  docs  not  seem 
to  !)<•  of  importance  in  the  production  of  the  interruptions,  its  practical 
hearing  being  the  fact  that  a  mixture  of  free  oxygen  and  hydrogen  is 
explosive  if  ignited  by  a  spark.  Such  an  interrupter  should  alwavs  he 
provided  with  free  ventilation.  The  operation  of  a  Caldwell  interrupter 
is  accompanied  by  the  production  of  irritating  sulphurous  acid  fumes 
and  l>y  heating  ot  the  liquid.  \\  hen  the  liquid  gets  too  hot  the  inter- 
rupt<'r  will  no  longer  act  and  it  is  desirable  to  have  several  interrupters 
and  simple  switches  to  connect  different  ones  with  the  coil.  If  these 
have  pin-holes  of  different  sizes  we  have  the  added  advantage  of  being 
able  to  select  the  si/.e  best  adapted  to  the  case  in  hand.  The  smaller 
the  pin-holes  the  more  rapid  are  the  interruptions  and  the  less  powerful 
is  each  impulse  sent  through  the  tube  bv  the  secondary  coil.  This  is  a 
desideratum  for  treatment  and  for  the  lighter  forms  of  radiography, 
while  for  the  heavier  radiographic  work  such  an  interrupter  should 
have  large  pin-holes.  With  the  small  pin-holes  the  primarv  current 
when  turned  on  full  is  only  o  or  1  amperes,  while  with  large  holes  it  mav 
be  as  heavy  as  11  amperes.  There  are.  of  course,  modifications  of  this 
simple  type,  and  in  one  of  them  the  size  of  the  communication  between 
the  two  portions  ot  fluid  can  be  regulated  by  the  motion  of  a  conic 
plug,  which  more  or  loss  completely  fills  the  hole.  l"p  to  the  limit  of 
its  capacity  the  Caldwell  interrupter  is  one  of  the  most  satisfactory  in 
the  production  of  a  brilliant  steady  .r-radiance. 

I  he  II  <  Inn  It  / iitci'i'H jitcr  consists  of  a  single  jar  of  dilute  sulphuric 
acid.  The  i icgat ive  electrode  is  of  lead :  the  posit ive  electrode  or  anode 
,  being  a  platinum  rod  enclosed  in  a  closolv  fitting,  very  tough,  porcelain 
tube  mid  the  distance  that  it  projects  beyond  the  end  of  the  tube  can 
be  regulated.  The  greater  the  surface  of  the  platinum  point  exposed 
to  the  fluid,  the  more  powerful  is  the  current  and  in  a  general  way 
the  slower  are  the  interruptions.  When  in  active  operation  the 
platinum  point  is  seen  enveloped  in  a  regular  flame  and  the  fluid  about 
it  i-  cloudy  and  fiercely  agitated.  The  probable  cause  of  the  interrup- 
tions is  the  production  of  a  layer  of  steam  covering  the  whole  surface 
ot  the  platinum  point.  There  is.  however,  vigorous  elect  rolvsis  going 
on  with  the  generation  of  hydrogen  chiefly  at  the  negative  pole  and  of 
oxygen  chiefly  at  the  platinum  point  forming  the  anode.  And  owing 
to  soli-inductance  and  an  inverse  current  in  the  primary  circuit,  there  is 
al-o.  to  a  lesser  extent,  a  liberation  of  hydrogen  at  the  anode.  The 
bubble-  o|  gas  do  not  form  a  sufficiently  uniform  covering  on  the  anode 
to  account  torthe  interrupt  ions,  t  hough  t  hey  doubtless  exert  an  influence 
upon  the  nature  of  the  interruptions  produced.  With  this  interrupter 
the  iluid  becomes  hot  and  the  apparatus  fails  to  work  after  continuous 
use,  so  that  it  is  necessary  either  to  have  one  containing  a  very  laru'e 
amount  of  liquid  or  to  have  more  than  one  interrupter.  The  \\ehneh 
interrupter  is  often  made  with  more  than  one  anode  and  if  so  the  plati- 
num tips  may  be  ot  different  sixes.  There  is  the  same  necessity  tor 
vetit  ilat  ion  ni  order  to  avoid  explosion.  The  \\  el  melt  int  errupt  er  must 
not  be  run  with  the  poles  reversed.  If  the  negative  wire  is  connected 
with  the  platinum  point  and  the  positive  wire  with  the  lead  electrode 
'  the  interruption-,  it'  produced  at  all.  are  of  a  deeper  and  rougher  sound 
and  the  current  very  quickly  corrodes  the  platinum  point.  For  this 
reason  the  \\  el  melt  in  t  errupt  er  is  not  suit  able  for  use  wit  h  an  alt  era  at  ing 
current,  or.  if  it  i-  so  used,  the  expensive  platinum  point  should  be 


N>1  MKDH'AL     KLKCTUli'ITY     AND     IJuNTliKN     KAYS 

replaced  by  one  of  copper  wire  which  can  lie  renewed  as  fast  as  it  is 
consumed. 

The  Caldwell  interrupter  may  he  used  with  an  alternating  current 
hy  introducing  an  tilu/iii/inni  r< //  into  the  supply  circuit.  This  is  a  cell 
tilled  with  a  ti  per  cent,  solution  of  Rochelle  salt;  the  two  electrodes 
beim:  of  aluminum  and  lead  respectively.  This  acts  hy  suppressing 
the  impulses  in  one  direction  and,  of  course,  is  much  less  efficient  than 
a  commutator  or  any  form  of  dynamo  in  which  the  alternating  current 
generates  a  continuous  direct  current.  Still,  a  Caldwell  interrupter 
and  an  aluminum  cell  form  a  simple  and  inexpensive  combination  and 
produce  a  very  good  .r-radiance  for  treatment  or  for  the  lighter  demands 
oi  radiography. 

Mechanic  interrupters  are  made  on  two  different  principles.  In 
the  older  type  the  contact  is  made  and  broken  by  the  vibration  of  an 
armature  in  front  of  an  electromagnet.  The  primary  current,  or  a 
shunted  portion  of  the  primary  current,  parses  through  a  coil  of  wire 
surrounding  a  core  of  soft  iron  which  becomes  a  powerful  magnet  the 
moment  the  current  begins  to  flow.  This  pulls  the  armature,  which  is 


I'lLT.  ."i-lO.-  Improved  <.,Mie<'M  independent  vibrating  interrupter. 

on  a  .-prinir.  1  oward  it ,  and  thus  the  connection  is  broken  and,  of  course, 
tin-  mm  ceases  to  he  a  magnet  and  allows  the  armature  to  spring  hack 
to  its  original  position,  where  the  contact   is  again  made.     One  of  the 
supply   wires   leading  from   the  wall  socket    to   l  he  apparatus  is  cut    in 
two  and  one  end  is  connected  with  the  armature  and  the  other  is  con- 
nected   with   t  he   metal   against    which   the  armature  is  pressed  bv  the 
spring.      The  rate  ()f  vibration  depends  partly   upon  the  weight  of  the 
armatun     and    partly  upon    the   distance    it    has    to    travel,   and    this   is 
adjustable   hy    means   ot    a   screw.      Such    an    interrupter  of  an 
improved  de.-imi  is  shown  in   FILL'.  ">10.      The  interruptions  produced  are 
than    is   i  he   case   with   a   liquid    interrupter  and   it    is  not 
:    the  heaviest    currents,  so  that    its  utihtv   in   radiography  is 
!.       ('   is  especially  useful   for  tivatmeni    work    because 
ill  day  long. 

M <  I'lni nic  I >it<  rni /il<  r.      \nother  mechanic  interrupter 

'•en    developed,   by   diifei'eiit    manufacturers  in    America 

-lightly    different     lines.       Iv-sent  ially    it    depends 

up"!)  in    of    a     \\heel    in    which    two    opposite    spokes    are 

toi'i:.'    ;  permanent   mamiet.      This  i-  placed  near  the  end  of 


TDK    .r-KAY 


855 


the  iron  core  of  the  induction-coil.  The  hitter,  of  course,  is  a  powerful 
electromagnet  with  a  certain  polarity  during  the  llo\v  of  the  current, 
and  ceases  to  he  a  magnet  after  the  current  stops.  The  positive  pole 
of  the  revolving  magnet  when  in  a  certain  position  is  attracted  by  the 
iron  core  of  the  coil,  and  this  attraction  causes  the  wheel  to  revolve 
into  such  a  position  as  to  bring  this  pole  of  the  magnet  as  near  as  possible 
to  the  iron  core.  By  the  time  it  has  reached  this  position  the  break  in 
the  circuit  has  occurred,  the  iron  core  is  no  longer  an  electromagnet, 
and  the  momentum  of  the  wheel  carries  it  around  to  such  a  position  that 
the  newly  and  oppositely  magnetized  iron  core  attracts  the  other  pole  of 
the  revolving  magnet.  The  motion  is  a  continuous  one,  resembling  that 
of  a  windwheel  or  a  water-mill.  The  rapidity  of  revolution  may  be  varied 
by  changing  the  distance  between  the  revolving  and  stationary  magnets. 
The  com  act  occurs  between  two  flat  metal  surfaces,  -^  inch  in  diameter, 
and  there  is  considerable  sparking.  The  interrupter  is  contained  in  a 
box  lined  with  sheet-iron  to  prevent  the  sparks  from  setting  fire  to  the 
box  or  neighboring  objects.  If  too  strong  a  current  is  turned  on,  or  if  the 
interrupter  is  not  working  properly,  the  contact  surfaces  may  become 
welded  together.  This  is  not  a  .serious  accident,  however,  for  usually  only 
a  small  part  of  the  two  surfaces  adhere  to  each  other  and  they  are  easily 
separated  and  smoothed  again.  A  con- 
denser weighing  five  or  ten  pounds  is  re- 
quired with  this  interrupter  and  a  rheostat 
with  a  minimum  of  S  and  a  maximum  of 
It)  ohms  resistance.  This  will  interrupt  a 
current  of  as  little  as  \  ampere  and  as 
much  as  5  or  10  or  with  special  con- 
densers even  20  amperes.  It  is  especially 
useful  for  high-frequency  currents  and 
for  .r-ray  treatment  tubes  for  contact 
application  where  the  strength  of  current 
must  be  very  small.  It  is  made  especially 
for  the  1  10-volt  direct  current,  but  can 
be  used  with  an  alternating  current  and 
an  electrolytic  rectifier.  It  causes  a 
Miiller  No.  lo  .r-ray  tube  to  produce  a 
suitable  radiance  for  therapeutic  use.  It 
is  available  also  for  radiography  and 
gives  better  contrast,  but  takes  a  little 
longer  than  the  liquid  interrupters  with 

very  much  heavier  currents.  A  5-ampere  current  with  this  interrupter 
will  produce  a  radiograph  of  the  frontal  sinus  in  a  minute  which  is 
about  as  good  as  that  produced  by  IS  amperes  with  a  Wehnelt  inter- 
rupter in  thirty  seconds. 

\\hid  Interrupter*  trith  Mcrcuri/  J<1  and  Illuminating  (itt*  Arc 
Xupprcxsion.  —  Drault  and  some  of  the  other  European  manufacturers 
make  a  wheel  interrupter  on  the  same  principle  as  the  Wappler  inter- 
rupter, except  that  the  motion  of  the  revolving  magnet  actuates  a 
mercury  jet  interrupter  (Fig.  542).  The  interruptions  take  place  in  a 
closed  iron  cylinder  filled  with  illuminating  gas  which  is  non-combustible 
in  the  absence  of  air.  This  prevents  the  oxidation  of  the  mercury  and 
iron  which  takes  place  when  alcohol  is  used  to  suppress  arcing.  The 
apparatus,  therefore,  requires  less  cleaning.  The  same  claims  are  made 


for    wheel 


t'<>r  it  a-  I'nr  the  Wappler  wheel  interrupter,  hut,  of  course,  the  mereurj' 

turhine  make.-  it  a  little  more  (•(duplicated.  A  dan.u'erous  explosion 
\vouM  occur  it'  it  were  started  when  full  of  a  mixture  of  air  tun  I  illuminat- 
ing Li'as. 

Mi  /•<•///•</  'l'ni'li,m  ''in!  Mi  /•'•///•//  hi/i  I iiU/'/'u  jilt  !'••<.—  The  other  <:reat 
tvpe'  ot'  mechanic  interrupter  i>  one  in  \vlucli  the  contact  is  nmde  or 
hroken,  either  hv  the  throwing  of  a  revolving  jet  of  mercury  against 
metal  connections,  or  the  (lipping  of  a  metal  connect  inn  into  mercury. 
In  either  case  the  power  i>  usually  supplied  hy  an  electric  motor.  The 
mercurv  turlniie  ran  !><•  made  for  a  very  wide  ranire  ot  speed  and  can  l>e 
run  foi1  a  Ion u;  time.  1  n  l>oi  h  t  he  mercury  interrupters  there  is  a  layer  of 
'1  nr  oil  to  suppress  the  spark,  which  would  otherwi.-e  he  excessive 
and  whidi  wouM  cause  the  making  and 
hreakiliii  <if  the  contact  to  he  less  perfect 
1  hali  I  her  .-houl<  1  lie. 


/  ' '  •    h'ntiij'  I nli  i'/' "  /i1 1  i'  •  I'  I'j:    .">  loj.--  'I  hl~   is   made  hy  1  he  Sa  n  it  as  (  'oin- 

p    '  '     of    herlin.   and   is    a   mercury  interrupter  m   which    the   arcing   is 

.'•--'•  i     hv     petroleum     oil.      'I  he     metallic     vessel     con)  a  mum'     the 

;•'•-  at    a   hi'_;h   rate  of  speed.      The  mercury  i-  held  against 

•    •.'•--'•!  hv  centrifugal    force  and  'here    are    two   insulated 

•  ak    t  he  con  t  act    I  iet  \\  een   a    m<  t  a  I  rod  connect  hill'  wit  h 

tlie    revolving    mere  n"         The  claim   i-   made   for  it 

it  h  any  voltage,  or  thai   it  can  he  u-ed  wit  h  a  s1orap:e- 

irecl    eleci  ric-li'/lii    current .      1 1    is    al.-o   said    i  o 

<•  di-charn'e  ;han   I  he   \\elmelt    or  the  mercury  jet 

.     '••••.        I'lie      i'adiouraphic     and    Huofo-copic      rc.-ulls     .-hoiild      he 

; :     ly  hei  t < -r. 

fat-       i iili;    '<-/•  Ml,  ri,<it;,,'i  n,,,;  T'-i'iih-fifniM   Ciim-Htx.— 

on  i-  placed  het  •.'  een  the  a  I'm.-  of  a  pernia  nent, 

•    :   carrie-  at    it-  i|i-tal   <     iren    ty  a  -'rip  of  nickel, 

it1  mercury  \'.  hen   I  he   vihratm.u    iron   is  attracted 

'   '    •    ",.,„'!:'•'.  and  i-   rai-ed  out   oi  t  he  mercurv  when 


THK    .T-KAY 


the  soft  iron  is  attracted  li\-  the  otlici1  pole.  It  is  at  the  surface  of  the 
mercurv  that  tin'  current  for  the  .r-ray  coil  is  made  and  broken.  A 
weaker  current,  derived  by  a  shunt  from  the  alternating  or  the  tripha.se 
circuit  ,  passes  through  a  coil  which  surrounds  the  soil  iron,  and  makes  it 
an  elect  romagnet  with  a  periodic  reversal  of  polarity.  When  it  has  a 
certain  polarity  it  is  attracted  by  one  pole  of  the  horse-shoe  magnet  ,  and 
when  it  has  the  opposite  polarity  it  is  attracted  by  the  other  pole  of  the 
horse-shoe  magnet.  Its  periodicity  is  1  he  same  as  that  of  the  altornal  ing 
or  t  riphase  current  which  it  is  to  interrupt,  and  it  is  only  a  matter  of 
proper  adjustment  to  make  a  contact  with  the  mercury  during  the  (low 
of  currents  in  one  direction  ami  to  break  it  during  the  How  in  the  opposite 
direct  ion. 

To  use  it  with  t  riple-phase 
currents  one  connects  the 
interrupter  with  only  two  of 
the  wires  supplying  the  cur- 
rent. An  interrupter  upon 
this  principle  is  shown  in 
Fig.  .>!!. 

Oi'ilinuri/  vibrating  intcr- 
riijitir.^  of  the  type  familiar 
in  the  faradic  coil  are  not 
suitable  where  heavy  cur- 
rents are  to  be  employed. 
A  condenser  is  always  re- 
quired when  such  an  inter- 
rupter is  used. 

Among  the  earlier  types 
of  apparatus  was  the  Edison 
make  and  break  wheel  mak- 
to L'0.000  revolu- 
nute  when  run  by 

separate  motor.  It  required  a  blower  to  extinguish  arcs  and  made  a 
ureat  deal  of  noise.  The  switch  was  so  arranged  as  to  start  the  inter- 
rupter before  the  primary  current  was  turned  on.  The  Willyoung 
interrupter  was  similar,  but  the  contact  points  were  immersed  in  oil. 
which  reduced  the  arcing  and  noise. 

The  Jnlnixtnn  interrupter,  made  by  the  Westinghouse  Company,  is  a 
mechanic  interrupter    in    which  an    electric    motor  rotates'an  inclined 


Caldwell  or  Simon  and  with   the  Wehnelt   interrupter  no 
required,    but    for    any    form   of  mechanic  interrupter  a 

i'iit'i/1  //.-••'  /•  is  necessary.  This  consists  of  a  number  ot  sheet-  of  tin-foil 
in  two  -erics  of  layers,  one  series  connected  with  one  wire  and  the  other 
series  dovetailing  between  and  connected  with  the  other  wire.  All  these 
different  pieces  of  tin-foil  are  insulated  from  each  oilier  by  >heets  ot 
paraffin  paper  or  mica.  When  a  current  of  electricity  passing  through 
a  prnnarv  coil  is  suddenly  interrupted,  a  certain  amount  of  charge,  or 
difference  in  potential,  is  found  to  be  present  in  the  primarv  coil,  and 

. 

this,  of  course,  produces  a  current   in  the  prnnarv  coil  which  will  have 

dischare  of  th 


MKDH'AL    1.1. K<  THlrlTY    AM)    Kl  >.\ Tl.  K.N     HAYS 

or  difference  in  potential,  and  as  a  matter  of  fact  its  presence  does 
actuallv  make  the  difference  between  a  successful  induction-coil  and 
one  which  will  not  work  well.  Its  function  is  roughly  to  lie  compared 
to  that  of  a  llv-wherl  in  machinery.  The  necessity  for  a  condenser  in 
any  coil  with  a  mechanic  interrupter  adds  greatly  to  the  weight  of  the 
apparatus  and  makes  it  somewhat  less  available  for  a  portable  outfit. 
The  Self-inductance  in  the  Primary  Coil. — The  primary  coil  is 
of  comparatively  thick  wire,  wound  upon  a  long  spool,  and  may  be  in 
a  single  layer  or  in  several  lay.-rs.  If  the  latter,  the  self-inductance 
may  be  variable  by  means  of  plugs  or  screws,  so  that  the  current  may 
pass  through  onlv  one  layer  or  through  two  or  more.  In  the  latter 
case  the  connections  may  be  such  that  the  different  layers  in  use  form 
one  continuous  circuit  like  the  thread  on  a  spool,  or  they  may  form  two 
or  more  parallel  circuits.  There  is  an  induced  current  produced  in 
any  wire  near  another  in  which  a  current  of  electricity  passes,  and  this 
is  produced  even  if  the  two  wires  in  question  are  but  parts  of  the  same 
wire  coiled  in  several  turns.  Lewis  Jones,1  of  London,  has  published 
very  valuable  tracings  showing  the  difference  between  the  waves  of 
electricity  produced  in  the  secondary  coil  by  varying  the  self-induction 
in  the  primary.  He  finds  that  for  therapeutic  purposes  (faradic  coils 
very  much  smaller  than  the  induction-coils  for  .r-ray  work)  the  secondary 
current,  produced  with  a  small  self-induction  in  the  primary,  is  more 
effective  in  producing  muscular  contraction  and  less  painful  than  with 
large  self-induction.  The  difference  in  the  tracings  shows  that  with 
small  self-inductance  the  make  and  break  currents  reach  their  maximum 
at  one  bound  and  come  down  to  the  level  by  a  short  steep  curve;  whereas 
the  return  to  the  /.era  line  in  the  secondary  current  when  there  is  large 
self-induction  is  by  a  long  inclined  line.  In  the  case  of  .r-ray  coils  the 
practical  value  of  variable  self-induction  consists  in  the  fact  that  a  tube 
\vith  a  high  vacuum  generally  works  better  with  great  self-induction  and 
vice  versa.  This  is  because  the  tube  with  the  higher  vacuum  requires  a 
more  powerful  secondary  discharge,  and  this  is  just  what  is  produced  by 
a  primary  coil  with  large  self-induction.  Disconnecting  the  .r-ray  tube 
and  observing  merely  the  spark  passing  between  the  poles  of  the  coil, 
is  about  twice  as  long  and  twice  as  heavy  with  high  self- 
as  with  little  self-induction.  'Die  author  has  made  such  an 
t  with  a  12-inch  coil,  a  Caldwell  interrupter  with  small  holes, 
•o.-tat  resistance  all  out.  so  that  there  i<  no  external  resistance 
•t  current.  \\ith  the  long  primary  winding  and 
-inductance  a  heavy  spark  passed  across  a  space  of 
e  small  self-inductance  a  lighter  spark  passed  across 
inches.  In  the  case  of  the  greater  self-induction 
heavier  spark  the  amperemeter  showed  that  only 
g  t  h rough  t  he  primary  coil,  while  in  the  other  case 
re  flowing.  The  longer  primary  coil  of  w're,  of 


leavier  secondary  discharge  represents  an  increased 
me,  so  t  ha  t  t  here  are  t  wo  ways  in  which  the  quantity 
ing  through  the  primary  coil  is  varied  bv  conditions 

The  same  thing  which  is  true  of  the  spark  between 
pole.-  of  the  coil  is  al.-o  true,  in  a  general  way,  of  the 
pon  an  .r-ray  tube.  I'ut  heiv  there  are  several  other 
:i;.l.  (  'ct .  s,  I'JUl  :  Trans.  Arclii\  <  d'l  !lcc.  .Mr<i.,  Xov.  10,  1'JUl. 


Y  859 

dements,  so  that  sometimes  a  tube  will  give  a  better  radiance  ami  be 
more  free  from  inverse  discharge  with  great  self-inductance,  and  another 
tube  will  work  better  with  low  self-induction:  and  this  is  something 
which  cannot  always  be  determined  theoretically,  but  must  usually  be 
found  out  by  actual  trial.  Jt  is  a  good  working  rule  that  no  lube  will 
give  very  much  of  a  picture  of  any  part  of  t  he  body  unless  it  shows  quite 
a  beautiful  linage  of  the  same  part  in  the  lluoroscope.  (iiven  this 
favorable  radiance,  the  actual  taking  of  the  picture  is  largely  a  matter 
of  using  t  he  proper  strength  of  current  and  duration  of  exposure  required 
for  the  part  of  the  body  to  be  radiographed. 

The  Amount  of  Current  Passing  Through  the  Tube. — The  volume 
of  the  secondary  current,  as  shown  by  the  fatness  of  the  spark  between 
the  poles,  is  greater  when  more  of  the  platinum  point  is  exposed  in  the 
Wehnelt  interrupter,  the  primary  current  is  stronger  as  to  amperage, 
and  the  interruptions  are  less  rapid.  The  heavier  secondary  discharge 
throws  a  heavier  charge  through  the  .r-ray  tube  and  causes  the  anti- 
cathode  to  heat  up  more  quickly.  Too  heavy  a  charge  will  make  the 
platinum  white-hot  at  the  focus  point  and  in  another  instant  fuse  the 
platinum.  There  is  warning  enough  of  this,  however,  by  the  white  heat 
of  the  platinum  and  by  the  streak  starting  from  the  focus  point  and 
extending  at  a  right  angle  to  the  bluish  cathode  stream,  which  also  be- 
comes visible.  When  such  an  accident  occurs  it  is  the  end  of  the  tube 
as  far  as  that  exposure  goes,  but  later,  after  it  has  cooled,  it  may  be  found 
still  quite  serviceable,  and  the  author  has  taken  many  a  pelvic  picture 
with  a  heavy  anticathode  in  just  this  damaged  condition.  For  lighter 
work  where  greater  detail  is  possible,  of  course,  a  tube  with  an  unbroken 
surface  at  the  focus  point  would  be  preferable.  The  charge  which  one 
tube  \vill  stand  for  thirty  seconds  might  easily  burn  a  hole  as  large  as 
the  lead  of  a  pencil  completely  through  the  disk  in  another  tube.  ( ien- 
erally  speaking,  the  larger  the  tube  and  the  heavier  the  anticathode 
the  heavier  current  it  is  intended  to  stand.  The  charge  is  sometimes 
increased  by  increasing  the  self-inductance  in  the  primary  coil,  by 
increasing  the  length  of  the  platinum  point  exposed  in  the  Wehnelt 
interrupter,  and  by  reducing  the  resistance  in  the  rheostat.  The 
relation  between  regulation  of  the  primary  current  by  varying  the 
rheostat  and  by  varying  the  Wehnelt  interrupter  are  important.  In 
my  own  experiments  a  primary  current  of  10  amperes,  as  produced  by 
the  use  of  the  Wehnelt  without  any  rheostat,  produces  an  incomparably 
better  .r-radiance  than  by  exposing  a  greater  length  of  platinum  in  the 
interrupter  and  reducing  the  current  to  10  ampere.-  by  increasing  the 
resistance  in  the  rheostat.  In  fact,  a  (i-ampere  current  produced  by 
regulating  the  Wehnelt  alone  gives  very  much  better  results  than  a 
1'J-ampere  current  produced  by  the  other  method.  With  the  rheostat 
resistance  and  a  large  surface  of  platinum  exposed  the  interruptions 
are  halt  ing  and  irregular,  t  lie  secondary  discharge  weak  and  intermit  tent , 
and  the  .r-radiance  weak  and  flickering. 

The  quantity  of  electricity  passing  through  the  tube  is  a  very  great 
deal  smaller  than  the  quantity  passing  through  the  primary  coil.  The 
latter  for  a  great  many  cases  is  about  10  amperes,  while  the  former  is 
often  between  2  and  .'!  milliamperes.  The  potential  or  voltage  of  the 
discharge  from  the  secondary  coil  is  somewhere  in  the  region  of  a 
thousand  tunes  that  of  the  1 10-\olt  primary  circuit,  but  the  quan- 
tity of  electricity  in  the  secondary  is  only  about  TTO'ITTT  p'H't  a 


Still 


as    that    in    the    primary    current.     With    a    tran-former    the   primary 
•unvnt   i-  often  l2o  ampere-  and  the  current   through  the  .r-ray  tube  MO 
milliamperes.      For  a  long  time  it   was  found  impracticable  to  measure 
tiie  quantity  pas-ing  through  the  tube,  the  ten-ion  of  the  current  being 
-  '  great  a-  to  render  it  very  difficult  to  insulate  the  wire-  in  their  passage 
through    any    instrument.      In    the    summer    of    I'.Hll.    and    practically 
simultaneously.  <  iait'l'e   ot    I  ranee.  Snook   ot    Philadelphia,  and  \\eston 
of   New   .lersev   succeeded    in    making   practicable   instruments   for   this 
purp.i-e.      (  iait'l'e'-  i-  a  hot  wire  galvanometer,  and  Snook's  and  Weston's 
are   electromagnetic    galvanometers.     The   secret    of   success   seems   to 
have   been    the   discarding  of   the   idea    that    tremendous   insulation    is 
necessary.      The  difference  in   potential  at   different    parts  <,f  the  same 
wire   leading  from   the  coil   to   the  .c-ray   tube   is   comparatively   small. 
The  hot  wire  milliamperenieter  registers  the  -ame.  no  matter  how  much 
the  inverse  discharge  may  be  interfering  with  the  operation  of  the  tube, 
while    the    electromagnetic    meter    shows    ihi-    effect    at    once.      These 
meters  are  usually  marked  from  0  to   10  milliamperes  for  use  with  a 
coil,  and  from  0  to  '2  milliamperes  when  a  static  machine  is  used.      This 
represents  about   the  usual  difference  in  power  between  the  .r-radiance 
produced    by   the   coil    and    the   static   machine.      The   current    passing 
through  the  tube  measure-,  of  course,  not  only  the  power  generated  by 
the  nil   but   abo  the   resistance  in  the  tube,  and   this  varies  with,   its 
degree  of  vacuum.  -:>  that  the  instrument  i-  of  service  in  estimating  the 
:i  iwer  of  different   coil-  and  also  for  showing  the  condition  of  the  tube 
at  every  in-taut  of  the  exposure  in  making  a  radiograph.      To  a  certain 
extent   it    indicates   the  effectiveness  ot    the   ray   produced,   and   in   this 
way  -erves  a-  a  guide  to  the  length  of  time  required  for  the  exposure. 
The  same,  of  course,  holds  true  in  regard  to  the  therapeutic  use  of  the 
.."-ray.     All  thi-.  however,  i-  valueless  and  even  mi-leading  unless  corn- 
wit  h  the  many  other  factors  already  alluded  to  for  obtaining  or 
.••••••ogni/ing  the  proper  quality  of  radiance.      It    i-  e-pecially  important 

ot    to  rely  upon  this  milliamperenieter  on  the  secondary  circuit   to  the 

'•X'-lu-ion  or  neglect  of  the  amperemeter  on   the  primary  circuit.      The 

latter   indicate-   the  amount    of    current    admitted    to   the  apparatus;   it 

-!    •.-      hetli   r  there  is  danger  of  burning  out  the  primary  or  secondary 

rheostat  or  any  of  the  fuses.      If  one  i-  doing  heavy  work  at 

>]  itely  ' ntial   to  the  -afety  of  the  apparatus  to  have  an 

on  the  primary  circuit,  and  with  it  one  can  very  well  ac- 

de-irablc    effeH     \vitliollt     the     1 1  ]  i  1 1  la  11  Ipefeniet  er    oil     the 

;  lary  circuit,  thi-  being  in  radiography  with  an  induction  coil  onlv 
i  '    .'•  ;icci— -ory.  but  essential  with  a  tran-former. 
•     etneter    gives    exact    re-nit  - 


•    :  I'fect .  ]  ig   t  hen-    i.-   al>o   ;i   good 

-omet  inn  -    thi  c.      As    a    rule,,   however, 

le     inverse    (lischal'ge     I  he    ilireel     (li-charge    is 

I.    1:    •..':..-••.••••  : "  i-  1 .",.  I1. ni."i,  ii.  :;nii. 


Mil 


deficient  :  and  considerable  inverse  discharge  always  produce-  excessive 
wear  and  tear  upon  t  he  {  ulie. 

The  Point  and  Plate  Parallel  Spark-gap. — This  may  he  u-ed  as 
a  sort  of  valve  to  suppress  the  inverse  discharge.  It  is  placed  between 
the  poles  of  the  coil  and  so  near  together  that  the  discharge  in  one 
direction  (/.  e.,  when  the  plate  forms  the  cathode  and  there  i>  an  inverse 
discharge)  will  pass  across  the  spark-uap.  If  the  distance  is  properly 
adjusted  t  he  i  list-harp-  in  t  he  opposite  direct  ion  cannot  cross  the  a  ir-u'a  p. 
but  will  be  dri\en  through  the  tube.  The  point  should  be  connected 
with  1  he  cat  h  ode  and  t  he  plate  with  1  he  anode  of  the  tube  (  Fi^.  ^\^i) . 

Measurement  of  the  Difference  in  Potential  at  the  Poles  of 
an  ./'-Ray  Tube. — A  -tatic  voltmeter  may  measure  the  difference  in 
potential  between  the  TWO  poles  of  an  ./'-ray  tube  and  consequently 
the  resistance  of  the  tube.  The  voltage  is  so  ^real  that  (iaif'fe'has 
adopted  the  expedient  of  connecting  the  poles  of  the  tubes  to  a  series 
of  condensers.  The  armatures  of  one  of  the  condensers  are  connected 
with  the  static  volt  mot  or.  The  fraction  of  the  voltaire  thus  measured 
is  one  divided  by  the  number  of  condensers.  The  uTaduations  on  the 
voltmeter  may  be  in  volts  or  directly  in  decrees  of  the  Henoist  radio- 
chromometer.  but  the  graduation  must  be  done  for  The  particular 
apparatus  that  the  voltmeter  is  to  be  used  with. 


'i p<  i'(  N  ond   I'ncl'-uj/   in   u  (icix-jUlcd    Tiibi 


ill     I  //(•//<! //<jt  i!     \  acuiitn.      liul(.r    t,f     It* 


power  in  the  ti'enerator  increases  not  only  the  milliainperage  which 
passes  through  the  tube  but  also  To  a.  !e»  extent  the  bark-up  of  the 
tube.  Very  short  exposures  which  do  not  change  the  decree  of  vacuum 
may  show  that  with  a  certain  amount  of  power  the  milliamporago  is  ,~> 
and  the  back-up  or  .-park  equivalent  \  inches,  if  now  the  power  is 
increased  so  that  the  milliampere.-  become  '_'(>.  it  will  be  found  that  the 
spark  equivalent  has  also  increased  probably  to  about  <s  inches.  The 
imli.r  i >f  rncnui/i  is  the  same,  however,  and  i-  found  by  dividing  the 
square  "t"  the  number  of  inche-  back-up  by  the  number  of  milliampere.-. 


the  same  relations  between  the  miliiamperage  and  spark-gap  as  with 
the  ma— filled  t  uhe  i  pame  *<»!  V  Turning  on  more  power  may  simply  in- 
crea-e  the  number  of  inilliainperes  with  little  change  in  the  spark 
equivalent,  until  a  cur/'tnt  of  xdturafion  is  reached.  This  is  the  greatest 
number  of  milliampere-  which  will  pass  through  the  tube  at  a  certain 
voltame.  Additional  power  after  that  increases  both  the  milliamperage 
and  the  back-up  i  spark  equivalent  or  voltage"  in  the  same  way  as  with 
the  mas-filled  tube.  Dividing  the  square  of  the  inches  resistance  by  the 
number  of  inilliainperes  gives  a  constant  figure  if  the  filament  incandes- 
cence is  unchanged. 

Backing  for  the  Plate  in  Radiography. — There  are  many  conditions 
in  which  it  i-  desirable  that  more  or  less  of  the  patient's  weight  shall 
rest  upon  the  plate.  This  makes  my  backing  for  .r-ray  plates  very 
desirable.  It  consists  of  a  board,  measnirng  11  by  17  inches  and 
^  inch  thick,  covered  on  its  lower  surface'  by  smooth  cardboard  and 
on  its  upper  surface  by  .r-ray  metal  and  bou.id  around  the  edges  with 
adhesive  plaster.  It  is  thin  enough  to  be  placed  upon  the  table  under 
any  part  of  the  patient  without  discomfort,  and  strong  enough  to  prevent 
the  plate  from  breaking  under  the  weight  of  the  heaviest  patient.  Its 
under  -urface  is  smooth  enough  not  to  scratch  the  polished  wood  top 
of  a  table,  and  its  strength  is  such  that  it  may  be  used  on  top  of  cushions 
or  in  bed.  where  otherwise  the  patient's  weight  would  assuredly  break 
the  photographic  plate.  The  .r-ray  metal  .-urface  prevents  diffused 
rays  from  reaching  the  plate  from  behind. 

Radiographs  Made  With  a.  Single  Flash. — This  is  most  practicable 
with  a  cartridme  fuse  which  will  burn  out  the  instant  that  a  very  heavy 
current  is  turned  on  and  a  single  permanent  break  occurs  in  the  primary 
current  and  a  -ingle  induction  discharge  passes  through  the  .r-ray  tube. 
The  current  should  be  stronger  than  is  ordinarily  employed  and  if  the 
.r-ray  tube  is  absolutely  in  readiness,  especially  as  to  the  degree  of  vac- 
uum, a  really  instantaneous  j-ray  picture  may  be  obtained.  The 
amount  of  impression  upon  the  plate  in  such  a  short  time  will,  of  course, 
depend  upon  the  strength  of  the  current.  Wonderfully  clear  gastro- 
intestinal  radiographs  have  been  made  in  this  way. 

By  usinm  the  negative  cinematograph  film  between  two  intensifying 
screens  i  he  heart  may  be  radiographed  in  motion.  A  number  of  such 
picture-,  taken  at  different  parts  of  the  cardiac  cycle,  could  be  used  in 
the  cinematomraph  to  .-how  the  heart  in  motion. 

')•'-  menerator  has  ;)   time  switch   which   ha- 
pie   phase   circuit-,  and   be-ides   t 


THE    0--KAY  Stj.'i 

that  the  strong  current  has  ceased.  This  is  followed  by  just  the 
grinding  noise  of  the  time-switch  revolving  if  one  has  relaxed  the  pres- 
sure promptly  after  the  first  click.  But  one  may  continue  to  press  upon 
the  botton  and  then  each  second  there  is  a  repetition  of  the  two  clicks 
and  of  the  exposure  lasting  a  fraction  of  a  second.  A  single  exposure 
may  be  from  ,',-;  to  ^.j  second.  Two  one-second  exposures  with  an  ex- 
tremely short  interval  is  the  same  as  two  seconds'  continuous  exposure. 
Any  whole  number  of  seconds  can  be  accurately  measured  in  this  way. 
One  and  a  half  seconds  can  be  measured  exactly  by  setting  the  time 
switch  for  three-quarters  second  and  allowing  two  such  exposures  with 
the  accompanying  interval  of  less  than  one-quarter  second. 

The  Eastman  Timer. — This  is  an  ordinary  sized  clock  which  has 
only  one  hand  which  makes  a  complete  revolution  in  sixty  seconds. 
Five  seconds  look  the  same  as  five  minutes  usually  do.  The  hand  is 
large'  enough  to  be  seen  by  the  ruby  light  of  the  dark-room  and  so  are 
the  graduations  which  represent  seconds  and  halves  and  quarters  of  a 
second.  The  author  times  all  exposures  of  two  seconds  or  more  by 
hand,  guided  by  this  timer  which  hangs  upon  the  switch-board. 

Automatic  Timers. — Every  a'-ray  manufacturer  makes  his  own 
appliance,  which,  being  set  for  a  certain  time,  breaks  the  primary  cur- 
rent after  it  has  been  turned  on  for  that  length  of  time.  For  exposures 
of  a  second  or  less  they  are  invaluable,  and  they  are  very  useful  for  ex- 
posures of  any  length. 

Fluorophotography. — This  process,  which  consists  in  making  a 
photograph  of  the  image  on  a  fluorescent  screen,  was  first  published 
by  Dr.  J.  M.  Bleyer.1  It  does  not  seem  to  present  any  advantage  over 
ordinary  radiography  directly  upon  the  plate  or  film  unless  one  desires 
a  reduced  sized  picture. 

Radiographic  Determination  of  Death.- — Yoileant2  says  that  a 
radiograph  of  a  dead  person  shows  the  stomach  and  all  intestinal 
convolutions  very  clearly;  in  the  living  person  the  constant  peristaltic 
and  respiratory  movements  obscure  the  outlines  of  the  different  struc- 
ture. This  is  especially  true  with  rather  long  exposures,  such  as  a 
minute  or  several  minutes. 

The  Radiograph  a  Professional  Secret. — The  Paris  Academy  of 
Medicine  has  resolved:  "A  radiograph  is  a  document  consisting  of 
something  taken  directly  from  the  patient,  is  something  of  the  per- 
sonality of  the  patient,  and,  therefore,  the  use  of  a  radiograph  comes 
under  the  law  (.if  professional  secrecy  in  its  strictest  sense.  Take,  for 
example,  a  case  of  early  phthisis,  or  a  man  with  syphilitic  exostoses. 
examined  by  a  man  outside  of  the  medical  profession  who  is  not  bound 
to  professional  secrecy.'' 

x-Ray  Work  in  the  Tropics;  Difficulties  Due  to  Atmospheric  Moist- 
ure.- In  ( 'hina  and  similar  places  all  parts  of  the  generator,  the  con- 
ducting wirc^s,  and  the  .r-ray  tube  are  often  covered  with  a  film  of  moist- 
ure like  the  moisture  on  the  outside  of  a  glass  of  ice-water.  This  oc- 
casions such  a  leakage  of  electricity  that  it  may  be  impossible  to  secure 
a  sufficiently  high  tension  discharge  through  the  .r-ray  tube.  Fven  the 
oil  in  the  transformer  may  be  covered  by  a  film  of  moisture. 

To  remedy  this  the  high-tension  conducting  wires  must  not  be  bare, 
as  is  often  the  case  in  Xew  York,  but  must  be  heavily  insulated  with  a 


Nt  I  MKDH'AL    Kl.l.i  TKHITY 

water-proof  material  and  he  wiped  dry  just  before  the  current  is  turned 
on.  The  .r-ray  tube  should  also  be  wiped  dry.  The  generator  of  high- 
tension  current  should  be  completely  enclosed  in  an  air-tight  cabinet. 
the  interior  of  which  is  kept  free  from  moisture  by  air  circulating  through 
it  from  a  dehydrating  apparatus. 

I )i  I/ i/i/nit/ni!.-  This  process  was  originated  for  the  preservation  of 
fruit  in  a  natural  state  except  for  a  reduction  in  si/e  and  weight  due  to 
the  hiss  of  water.  This  is  accomplished  at  the  ordinary  temperature 
by  exposure  in  a  closed  space  to  a  current  of  ail'  previously  deprived 
of  its  usual  moisture.  The  air  first  passes  through  a  closed  space  where 
it  i-  in  contact  with  refrigerator  pipes  upon  which  its  moisture  is  de- 
posited as  a  1  hick  layer  of  frost.  This  is  because  air  at  a  low  temperature 
can  retain  in  solution  much  less  moisture.  The  air  then  passes  through 
a  closed  space  in  which  it  is  warmed  to  the  ordinary  temperature  and 
becomes  ready  to  absorb  a  great  deal  of  moisture  on  passing  into  the 
closed  space  containing  the  articles  to  be  dehydrated. 

For  .r-ray  purposes  the  air  leaving  the  closed  space  containing  the 
generator  can  be  used  over  again  instead  of  extracting  the  moisture  from  a 
fresh  quantity  of  air.  It  had  better  be  filtered  through  three  thicknesses 
of  cheese-cloth  to  arrest  metallic  particles  derived  from  the  generator. 

A  home-made  outfit  might  comprise  a  long  coil  of  pipe  in  a  closed 
space  filled  with  a  freezing  mixture  such  as  ice  and  salt,  and  a  heater 
oi  any  kind  to  warm  the  air  again  before  it  enters  the  space  enclosing 
the  generator. 

Where  refrigerating  machinery  and  even  ice  are  not  available. 
the  air  may  be  sent  through  a  space  where  it  is  in  contact  with  an 
extensive  surface  of  quicklime  or  of  calcium  chlorid.  The  same  air 
circiilat inu'  through  this  space  will  be  deprived  of  most  of  its  moist- 
ure. ( 'alcium  chlorid  is  especially  desirable  because  it  can  be  taken 
out,  dried  out  thoroughly  by  heat,  and  replaced,  care  being  taken  not  t< 
admit  anv  considerable  amount  of  outside  air. 


LOCALIZATION  OF  FOREIGN  BODIES 

P>n!l«'ts  a,,,l  other  foreign  bodies  embedded  in  the  flesh  may  be 
:•  Iv  seen  with  the  fluoroscope  and  in  the  radiograph,  and  still  it  may 
In-  somewhat  dillicult  to  say  at  just  what  depth  they  are  located  in 
the  tissues.  This  information  may  be  directly  gained  in  any  portion 
of  one  of  i  he  limbs  by  making  t  wo  successive  radiographs  at  a  right  angle 
to  each  other.  It  will  greatly  facilitate  the  surgical  removal  if  a  metal 
marker  like  a  small  -hoi  or  a  very  short  piece  o|  heavy  wire  be  fastened 
u  it  h  adhesive  pla-t  er  to  mark  the  \v<  mi  id  oi  cut  ranee.  This  should  be  in 
I  •  he  plate  and.  therefore,  at  t  he  center  of  1  he  first  radiograph 
and  -hould  be  at  t  he  ext  reine  edge  of  t  he  image  o!  t  he  limb  in  t  he  second. 

Iii  Fi-.i's.  ."in  and  .";  17,  referred  for  examination  by  I  )r.  \Yadhams,  the 
lateral  radiograph  -howed  a  needle  broken  oi'i  in  the  heel  '  inch  in  from 
oiind  of  entrance  ,-md  extending  upward  and  backward  tor  1  inch. 
Tl  ipo-terior  radiograph  sho\\ed  that  the  needle  did  not  incline 

•  ,'  .  .  m  a  median  plane.  h  was  easy  enough  for 

i  :.•  •  -  '  tin  ud  remove  it . 

W.  M.l'i  .  .  ..  if  New  York,  was  among  t  he  fir-t  t  o  suggest  fa.-tening 
1  '  '  i  o  1 1  e  -kin  eit  her  tow.- 1  rd  or  away  from  t  he  pi  a  t  e  in  coii- 

Ilio,  litlr;,!  ion    of    !  he    M  a  ckel  l/Ie-I  )a  Vld-ol  I     localize!'. 


THE    X-KAY 


805 


in.  o4G. — I.neali/ation  of  noodle  in  heel.      Lateral  \ie\\-  showing  needle  and  metal  market 


860 


MKDICAL    KLKCTHK  1TY    AND    ROXTGEN    KAYS 


Foreign  substances  in  any  part  of  the  trunk  may  be  localized  by 
making  two  successive  radiographs  upon  two  separate  plates  with  the 
body  in  the  same  position  with  reference  to  the  plates  and  with  the  tube 
shift (>d  a  certain  distance  to  one  side  for  the  second  picture.  A  calcula- 
tion based  upon  the  distance  from  the  .r-ray  tube  to  the  plate,  the  dis- 
tance to  which  the  tube  i<  displaced  laterally,  and  the  resulting  displace- 
ment of  the  image  of  the  foreign  body  will  give  the  distance  of  the  latter 
from  the  plate. 

THE  AUTHOR'S  METHOD  OF  LOCALIZATION ' 

The  .r-ray  tube  has  its  anticathode  at  a  distance  of  14  inches  from 
the  plate  for  the,  extremities  and  is  moved  laterally  2  inches  after  the 
first  radiograph.  And  for  the  trunk  or  head  the  distance  is  21  inches 
and  the  displacement  3  inches.  A  lead  mark  is  fastened  upon  the 
surface  in  contact  with  the  plate,  replaced  afterward  by  a  mark  with 


Fig.  -VIS. — Position  of  the  image  of  the  foreign  body  in  the  thigh  in  the  first  radiograph. 

iodin  or  nitrate  of  silver,  for  a  guide  at  the  time  of  operation.  A  gal- 
vani/ed  wire  net  ''i-inch  mesh"  which  with  the  thickness  of  the  wire  has  7 
subdivisions  to  the  linear  inch  is  laid  over  the  plate.  A  double  expostire 
shows  the  lead  mark  and  the  wire  net  stationary,  but  two  images  of 
the  foreign  body.  The  meshes  enable  one  to  determine  amount  of 
displacement,  selecting  the  same  part  of  each  image,  and  the  appended 
tables  enable  one  to  determine  the  distance  of  the  foreign  body  from 
the  plane  of  the  plate,  and  the  relation  of  the  foreign  body  to  the  lead 
mark  i-  also  shown.  If  two  plates  are  used  the  number  of  subdivisions 
i  <f  displacement  of  the  image  is  easily  determined. 

Instead  of  usintr  the  wire  mesh  at  the  time  the  radiograph  or  radio- 
graph- are  made  a  sheet  of  transparent  celluloid  ruled  seven  lines  to 
th'1  iiii'.ir  inch  may  be  placed  in  contact  with  the  finished  plate  for 
tempi  >ra  rv  -t  ud  v. 

;  Sinclair  TOIIM-V.  New  York  Mod.  .Jour..  .lulv  »',.  l<t]"v 


807 


In  the  case  illustrated  the  base  of  the  foreign  body  is  two  meshes 
internal  to  the  wire  passing  through  the  lower  part  of  the  letter  T,  and 
in  the  other  picture  it  is  five  meshes  external  to  the  same  wire.  The 
image  has  been  displaced  seven  meshes  by  a  tube  displacement  of  ,'i 
inches  at  a  distance  of  21  inches.  Reference  to  the  table  shows 
that  the  foreign  body  was  at  a  distance  of  5.3  inches  from  the  wire 
netting  at  the  time  of  the  two  exposures.  I  advise  reference  to  the 


Fig   549. — Changed  position  of  the  image  of  the  foreign  body  in  the  second  radiograph. 
The  wire  net  and  the  lead  marker,  T,  are  fixed  landmarks. 


printed  table  rather  than  extemporaneous  calculation,  but  this  particular 
case  will  serve  to  show  the  manner  in  which  I  have  calculated  the  table. 


3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

1  1 

In 

16 

17 

IS 

19 

•J  ) 

21 


0.9 
1.8 
2.6 
3.2 
3.7 
4.6 
5.3 
5.7 
6.3 
6.8 
7.3 
7.7 
8.3 
8.7 
8.9 
9.1 
9.3 
9.6 
10.0 
10.3 
10..5 


Anticathode  distance  14  inches, 

tube  displacement  2  inches. 

Image  displaced        Indicates  foreign 

j-inch  meshes.  body  distance 

from  plate,  inches. 


1 

2 
3 
4 
5 
6 
7 
8 
9 
K) 
1  1 
!'_' 
13 
14 


0.9 
1.8 

2.5 
3.1 
3.7 
4.2 
4.7 
5.1 
5 .  ."> 
5.8 
6.1 
6.5 
6.7 
7.0 


The  Mackenzie-Davidson  Localizer. — This  is  tin1  prototype  of  a 
clas<  ot  apparatus  designed  to  u'ive  this  information  in  a  mechanical 
way.  ''.  i  .,  without  mat hnnat ic  calculation.  The  photographic  plate  for 
each  picture  is  placed  under  cross-wires,  whose  position  may  be  marked 
upon  the  body  and  who>e  position  is  radiographed  upon  the  plate. 
The  aiiticathode  of  the  tube  is  placed  at  two  definite  places  for  the 
two  successive  pictures  HIT.  .Vil).  After  the  plates  have  been  devel- 
oped one  i-  placed  in  the  locali/er  so  that  the  cross-wires  of  the  latter 
coincide  \vith  the  imau'e  of  the  cross-wires  on  the  plate.  A  thread  is 
fastened  at  the  imam1  of  the  foreign  body  and  at  a  pointer  which  is  held 
iu-t  where  the  anticnthode  was  placed  for  this  picture.  A  thread  is 
drawn  in  a  Minilar  wav  from  the  iniauv  of  the  foreitrn  bodv  on  the  other 


. 


... 

on  !  In  IH  ice  u  pied  1  iy  t  he  ant  icat  hode.      The  place  where 
'     cross  ;-  the  place  occupied   by   the  foreign   bodv   rela- 

mraphic  plates     l"\<j;.  .V>(  I  . 

Strohl's  method  of  localization1   i-  one  of   the   mos!    interest  in<i   and 

rie-    made    during    the    \\oild    \\'ar.       It    i-    a    fluoro- 

I  lie  -creeu,   m  a   fixed   po-iiimi   do>e   o\'er   the    recuni- 

' I- •  r-ray  I  ube  \\  oiild  be  underiieat  h  and  !'reel\p  mox'able  in  a 

\bovc   the  .c-ray    tube  and   ino\-'uit:   \\ith   it    are   two 

.  about    1   inches  apart.      The  .r-ray  tube  i-  ino\'ed 

to    -U'1'  itiuii    thai    the   .-hadow   of   one    wire    fall-    upon    a    certain 

p 'int    in    i  ne    innu'e  ,.f   i  he   f.  irciu'ii    bod\-   and   a    marl;er   i-   laid   on    the 


TIIK    .T-HAY  809 

screen  at  that  point.  Then  the  tube  and  its  wires  are  moved  so  that 
the  shadow  of  the  other  wire  falls  upon  the  displaced  intake  of  the  same 
part  of  the  foreign  body,  and  another  marker  is  placed  there.  The  ap- 
paratus is  accompanied  by  a  rule  or  flat  measure  upon  which  the  dis- 
placement is  noted.  The  graduations  are  not  in  actual  centimeters  or 
inches  of  displacement,  but  show  directly  the  distance  to  the  foreign 
body  from  the  plane  of  the  screen.  No  extemporaneous  calculation 
and  not  even  a  reference  to  a  table  of  values  is  required.  A  table  en- 
ables one  to  read  the  distance-  from  the  plane  of  the  fluoroseopic  screen 
to  the  foreign  body  indicated  by  the  measured  distance  to  which  the 
linage  has  been  displaced.  The  surprising  feature  is  that  the  x-ray 
tube  does  not  have  to  be  placed  at  a  -perilled  distance  from  the  fluoro- 
seopic screen,  but  may  always  be  at  the  same  level,  while  with  a  small 
part  of  a  thin  patient  the  screen  may  be  at  a  level  several  inches  different 
from  that  when  a  large  part  of  a  stout  patient  is  examined.  It  reminds 
the  author  of  his  own  astonishment  at  being  able  with  the  orthodiscope 
to  draw  an  actual  size  picture  of  a  key  while  seeming  to  trace  the  greatly 
enlarged  fluoroseopic  image1  of  the  latter.  The  principles  involved  are 
somewhat  similar.  If  one  were  to  extemporize  such  a  localizer  it 
would  be  unwise1  to  calculate  the  measure  of  displacements  and  depths; 
it  would  be  desirable  to  make  a  sufficient  series  of  actual  measurements 
of  the  displacement  shown  by  objects  at  measured  distance  below  the 
screen.1 

The  Hirtz  Compass.- — This  is  an  apparatus  applied  to  the  surface 
of  the  body  at  the  time  of  operation  to  indicate  accurately  the  position 
of  a  foreign  body.  It  is  adjusted  by  a  series  of  fluoroseopic,  radio- 
graphic,  and  mathematical  procedures  which  are  succinctly  described 
by  Bowen.:: 

The  Cannula  and  Harpoon  Method  of  Localization. — This  is  a 
fluoroseopic  method  largely  employed  by  the  French  in  the  World  A\  ar. 
The  harpoon  is  a  straight  needle  barbed  at  the  end  like  a  fish-hook  so 
that  when  pushed  through  the  tissues  till  it  touches  the  foreign  sub- 
stance1 it  stays  there  until  the  time  of  operation. 

The  harpoon  is  guided  in  the1  right  direction  by  the1  cannula,  which 
does  noi  it>e-lf  enter  the1  flesh,  but  is  attache-el  to  a  forked  frame  and 
pa>ses  through  a  fluoroscopie  sere-en.  The-  patient's  limb,  for  example, 
is  between  the  two  forks  of  the1  frame  and  is  turned  so  that  the1  image1 
of  the  foreign  body  is  separate  from  the  bones.  The  cannula  and  a 
special  part  of  the  opposite1  fork  are  brought  directly  in  line1  with  the 
foreign  body  and  the  harpoon  thrust  through  the  tissues  into  contact 
wit  h  t  he  foreign  body. 

The  Parallax  Method  of  Localization.-  Several  excellent  devices, 
including  Annulet'-  ( Ira  Hirer's,  determine  fluoroscopieally  the  distance  at 
which  a  movable  metallic  test  object  niu-l  be  from  the  fluorescent 
screen  in  order  that  the-  displacement  of  it-  image1  may  equal  the-  dis- 
placement of  the  imaire  of  the  foreign  body. 

Antfinr'x  Device  for  A />]>h//i/<i  i//<    PurdUjnx  M<(l>«(l  KariioriraphicaUy. 


870  MEDICAL    KLF.CTKICITY    AND    RONTGEN    HAYS 

stoop  aluminum  stop-ladder  upon  each  step  of  which  is  a  lead  figure, 
numbered  from  1  at  the  bottom  to  8  at  the  top.  Two  exposures  arc 
made  on  the  same  or  different  plates.  If  the  displacement  of  the  linage 
of  the  foreign  body  exactly  equals  that  of  figure  1,  for  example,  then  it- 
is  at  tin*  same  distance  as  figure  1  from  the  plate.  Or  if  it  is  more1  than 
that  of  figure  1  and  less  than  that  of  figure  '2,  the  foreign  body  lies 
between  those  two  distances.  It  does  not  make  any  difference  what  the 
tube  distance  or  displacement  are  or  what  are  the  height  of  the  steps, 
but  there  should  be  some  fixed  mark  in  contact  with  the  plates  when  two 
are  used,  and  the  author's  wire  net  is  useful  for  comparing  the  displace- 
ments. No  table  of  values  need  be  referred  to. 

DEVELOPMENT  OF  JT-RAY  PICTURES 

The  dark  room  ought  to  be  entirely  free  from  ordinary  light,  either 
daylight  or  artificial  light,  except  as  allowed  to  enter  through  ruby 
and  orange  glass  or  their  equivalent.  If  it  is  a  room  with  windows  no 
number  of  dark  shades  and  ordinary  blinds  with  slats  are  going  to  exclude 
the  light  sufficiently.  Kit  her  all  the  panes  of  glass  must  be  treated 
as  described  later  or  else  solid  board  shutters  must  be  provided  which 
will  close  so  accurately  as  not  to  admit  a  solitary  ray  of  light.  In 
order  to  use  the  daylight  it  will  be  necessary  to  have  all  the  panes 
which  are  not  securely  boarded  up  consist  of  one  thickness  of  ruby  and 
one  thickness  of  orange  glass,  or  else  the  glass  may  be  ordinary  colorless 
ground  glass  pasted  over  with  two  thicknesses  of  the  red  paraffin-coated 
•paper  used  in  the  original  packing  of  sensit  i/ed  plates,  and  one  t  hickness 
of  the  orange  paper  known  as  "post-office  paper.1'  Such  a  window 
should  be  shielded  from  the  direct  rays  of  the  sun  and  if  the  window  is 
very  large,  or  if  there  is  more  than  one  window,  it  is  better  to  absolutely 
darken  all  but  about  2  square  feet  of  one  window,  and  treat  just  that 
area  so  as  to  admit  only  safe  light. 

Kxeollcnt  outfits  are  made  by  the  Polyphos  Klekt  ri/itats-(  iesell- 
schaft.  of  .Munich,  of  the  nature  of  shades  for  ready  application  to  the 
windows  of  a  room  in  order  to  convert  it  into  a  dark  room. 

The  dressing-room,  as  found  between  the  front  and  back  rooms  of 
many  city  houses,  forms  an  excellent  dark  room.1  The  doors  usually 
have  ground  glass  panels  and  these  may  be-  prepared  with  red  and 
orange  paper,  and  a  good  strong  artificial  light  of  any  kind,  placed  close 
to  the  outer  surface  of  one  of  the  panels,  will  send  just  the  right  amount 
of  safe  light  into  the  dark  room  to  enable  one  to  work  easily  and  to  see 
the  plate  rlearlv  enough  to  regulate  the  degree  of  development. 

In  i  he  same  way  if  the  dark  room  is  a  specially  constructed  box-like 
attair.  a  small  window  of  rubv  and  orange  glass  mav  be  cut  at  a  con- 
venient height  and  the  light  placed  outside. 

The  ( 'nt>/>t  r  J!(  iritf  //'<////  of  101  l-randlo-power  is  excellent  for  this 
purpose,  but  an  ordinary  incandescent  electric  light  may  be  used,  or 
a  11  ilxlxii-h  gas  burner,  or  a  powerful  oil  lamp.  In  the  case  of  any  but 
ooper  Hewitt  it  is  desirable  to  have  a  pair  of  planoconvex  lenses, 
s  inches  in  diameter,  acting  as  a  condenser;  otherwise  the  light 
be  loiind  too  weak  and  diffused  for  proper  studv  of  the  plate. 

In  every  ease  the  light  should  be  admitted  at  some  distance  from 
where  i  he  developing  travs  are  placed  and  should  be  strong  enough  to 
just  enable  one  to  see  everything  in  the  dark  room  and  to  read  the 
label.-  on  bottle-  if  the  latter  are  brought  close  to  the  rubv  window. 


THE    X-RAY  871 

Too  brilliant  a  light,  even  if  considered  safe  as  to  color,  will  act  upon 
the  plate  and  produce  either  flatness  or  fog. 

For  a  room  or  closet  without  windows  or  glass  doors  artificial  lit/fit 
inside  the  room  is  a  necessity.  A  16-candle-power  ordinary  incandes- 
cent electric  light  with  a  ground  glass  bulb  and  enveloped  in  two  thick- 
nesses of  ruby  and  one  of  post-office  paper  makes  a  safe  light  if  placed 
at  a  distance. 

A  lamp  is  made  expressly  for  this  purpose,  known  as  a  tiplc**, 
fronted,  natural  ruby  incandescent  electric  bulb,  and  either  a  Hi-  or  a  32- 
candle-power  lamp  may  be  used.  This  is  complete  in  itself,  but  it  is 
exceedingly  difficult  to  secure  one  dark  enough  to  give  a  safe  light.  An 
ordinary  ruby  bulb  may  be  placed  in  a  box  with  a  ruby  and  orange 
glass  window  measuring  about  4  by  5  inches.  Others  consist  of  an 
ordinary  S  candle-power  ruby  bulb  completely  enclosed  in  a  heavy  shade 
of  natural  ruby  glass.  The  whole  screws  into  any  ordinary  electric- 
light  socket  and  is  the  simplest  and  most  satisfactory  apparatus.  Ex- 
cellent dark-room  lanterns  are  made  with  a  candle  in  an  automatic 
candlestick,  which  keeps  the  flame  at  a  constant  level  until  it  is  com- 
pletely burned  out.  There  is  a  ruby  glass  chimney  closed  in  such  a 
way  at  the  top  and  bottom  that  while  there  is  a  circulation  of  air  through 
it  no  rays  of  ordinary  light  can  escape.  This  will  answer  every  purpose 
in  developing  the  smallest  films  and  plates,  but  will  not  give  enough 
light  for  the  larger  ones. 

Other  ruby  lamp*  are  made  in  various  si/es  with  an  oil  lamp  enclosed 
in  tin  with  a  window  of  two  sheets  of  glass,  one  ruby  and  one  orange. 

The  amount  of  time  for  which  the  plate  may  be  safely  exposed  to 
these  various  ruby  lights  is  to  be  most  carefully  considered.  Genewilly 
speaking,  the  process  of  taking  the  plate  or  film  from  its  original  con- 
tainer and  placing  it  in  the  black  and  orange  envelopes,  in  which  the 
exposure  to  the  x-ray  is  made,  and  again  removing  it  and  placing  it  in 
i  lie  developing  solutions,  should  be  done  without  any  unnecessary 
delay.  The  plate  is  most  liable  to  damage  before  it  has  been  put  into 
the  developing  solutions.  During  development  the  ruby  light  should 
not  be  allowed  to  shine  directly  upon  the  plate,  except  for  a  moment 
from  time  to  time  to  permit  of  examination.  If  the  plate  is  one  which 
is  of  such  a  character  as  to  require  only  a  few  minutes'  development, 
simply  shielding  it  from  the  direct  rays  of  the  ruby  light  will  suffice; 
but  if  it  requires  from  twenty  minutes  to  two  hours  or  more  for  develop- 
ment, the  tray  or  tank  in  which  it  is  developed  should  be  closely  covered 
during  all  this  time,  except  occasionally  for  examination.  These  inspec- 
tions of  the  plate  should  be  as  infrequent  and  as  brief  as  possible. 

Stainint/  Solution*. — Quite  another  way  of  protecting  the  plate  from 
actinic  light  during  the  process  of  development  is  by  the  use  of  an  agent 
which  stains  the  plate  and  the  developing  solutions  red,  and  enables 
the  whole  process  to  be  carried  out  by  ordinary  light.  One  such  agent 
is  a  liquid  sold  under  the  name  of  cox  in  and  looks  like  a  strong  solution 
of  cochineal.  The  plate  must  be  immersed  in  this  solution  for  two 
minutes  and  then  taken  directly  from  it  to  the  developer  without 
allowing  any  of  the  staining  fluid  to  drain  off.  While  the  developer 
is  acting  the  plate  must  not  be  taken  out  of  the  fluid  and  the  develop- 
ment must  be  watched  by  direct,  not  transmitted,  light.  When 
sufficiently  developed  the  plate  is  washed  off  in  water  and  placed  at 
once  in  the  acid  hypo.  After  fixing  completely,  place  the  plate  in  run- 


S72 


MKIHCAI.    KI.!:(  TRK  ITY    AM)    RUXTGE.N    HAYS 


THK    .r-HAY 


ning  water  for  half  an  hour  to  \vasli  out  the  hypo  and  the  red  stain  of 
the  roxin.  The  entire  process  after  once  getting  the  plate  into  t  he 
coxin  may  he  carried  out  by  daylight  or  artificial  light,  hut,  as  in  tin; 
other  cases,  it  is  better  to  shield  the  plate  from  a  strong  light  except 
when  necessary  to  see  how  the  development  is  progressing.  Dark 
colored  developing  trays  must  be  used.  In  putting  the  plate  into  the 
coxin  no  white  light  must  touch  the  plate,  so  it  is  either  necessary  to 
go  into  a  dark  room  or  to  have  a  black  transferring  bag.  by  means  of 
•which  the  plate  may  be  taken  from  its  envelope  and  placed  in  the  coxin 
without  exposure  to  light.  The  utility  of  this  method  is  apparent  when 
taking  and  developing  .r-ray  pictures  at  patients'  houses  or  under  any 


other  circumstances  where  a   regularly   equipped   "dark   room"   is  not 
available.     This  method  is  equally  available  ior  plates  and  films. 

Technic  of  Development.-  The  development  of  an  .r-ray  plate  i< 
carried  out  in  several  stages.  As  a  rule,  it  is  better  first  to  immer-e  the 
plate  in  water.  Wetting  tin1  plate  thoroughly  enables  the  developer 
to  How  over  the  plate  evenly  and  prevents  the  mottled  appearance 
which  \vi  Hi  Id  occur  if  certain  spots  on  t  he  plate  were  left  bare  of  developer 
ior  a  lime  while  chemic  action  was  already  taking  place  on  adjoining 
parts.  Some  other  operators  prefer  to  ^hde  the  dry  plate  into  1  he 
developer  and  cover  it  completely  by  a  wave-like  motion.  1  he  second 
part  o!  the  process  keeps  the  plate  in  the  developer  lor  the  necessary 
length  of  i  hue.  li  is  important  at  t  he  verv  beginning  of  t  his  stage  to  go 


S74 


MEDICAL    KLKCTHiriTY    AND    KONTCiEN    KAYS 


over  every  hit  of  the  surface  of  the  plate,  of  which  the  film  side  should 
he  uj).  with  a  tuft  of  cotton  or  the  finder-tips.  In  this  way  adherent  air- 
hells  are  removed.  If  these  were  left  the  cheinic  action  of  the  developer 
could  not  take  place  at  those  points  and  in  the  finished  plate  we  should 
see  a  number  of  transparent  spots.  These  appear  as  inky  black  spots 
upon  the  print  or  finished  picture.  A  picture  may  he  spoiled  by  such 
"pin-holes."  If  the  plate  has  been  moved  about  in  the  water  and  also 
in  the  developer,  air-bells  may  be  prevented  without  touching  the  sur- 
face1 of  the  plate1,  but  their  possibility  should  always  be1  borne  in  mind. 
Figure1  ">.">l2  shows  the'  plate  before  development.  It  is  a  deael  white1  and 
as  opaque1  as  thin  porevlain.  After  a  certain  length  of  time1  in  the 
developer  an  "image"  becomes  visible  upon  the1  plate;  it  is  produced 


paquo 


by  the  part  of  the  plate  more1  directly  exposed  to  the  .r-ray  darkening 
under  the  action  of  the  developer.  The  subject  of  the  picture  shows 
at  fir^i  as  a  white  -ilhouette;  for  instance,  if  it  is  a  hand  it  shows  merely 
the  white  hand  without  any  indication  of  the'  bones.  As  the1  devel- 
opment progresses  the  portion  of  the  plate  affected  by  the  .r-ray. 
which  ha-  passed  through  the  soft  parts  darkens  up  somewhat  and  we1 
have  three  general  shades;  the'  comparat  ive  whiteness  of  the1  bones,  e)r 
any  t'oreiun  body,  the  moderate  darkness  of  the'  flesh,  and  the1  blackness 
of  the  bare  portion  of  the  plate.  The  bare  portion  of  the1  plate1  in- 
rreases  in  opacity,  while-  the-  part  ce>ve-red  by  the  object  remains  trans- 
lucent. The  iinau'e.  t  heivfore,  is  visible  by  transmitted  as  we'll  as 
reflected  htrht.  Figure  .">.">;$  shows  the1  appearane-e-  of  a  plate  after  (level- 


THE    X-RAY 


875 


opniont  and  Fig.  554  after  fixing.  The  latter  process  dissolves  out 
the  unchanged  silver  salt  and  makes  the  plate  lose  its  dead  white 
appearance  and  become  perfectly  transparent  at  the  places  where  the 
tissues  were  densest  and  the  plate  was  least  affected  by  the  x-ray. 
Fig.  555  is  the  radiograph  whose  development  has  been  depicted 
in  the  previous  figure.  It  would  have  been  better  for  longer  devel- 
opment. It  is  a  fatal  error  to  stop  the  development  too  soon.  In  that 
case  you  have  a  thin  plate  possibly  with  plenty  of  detail,  but  one  from 
which  it  is  impossible  to  make  a  good  print.  As  the  development 
proceeds  the  portions  of  the  plate  which  represent  the  shadow  of  the 
Mesh  and  bones  become  darker,  and  the  image  appears  to  be  fading  out. 


"j'~)4. — Plato  after  development  and  fixation.     The  "  hypo  "  has  removed  every  trace 


of  niilkiness  and  the  thinner  parts  are  transparent. 


This  is  very  apt  to  frighten  the  beginner,  but  it  is  just  exactly  what 
should  happen;  if  the  development  is  stopped  before  the  bones  have 
darkened  to  sonic  extent  the  resulting  picture  will  give  merely  a  silhou- 
ette of  the  bones  without  the  structural  detail  which  the  best  x-ray  work 
should  show.  Even  if  the  image  disappears  entirely  and  the  plate 
appears  entirely  black  the  picture  of  the  bones  is  still  there  and,  perhaps, 
with  more  detail  than  could  have  been  obtained  with  a  shorter  develop- 
ment. In  a  general  way,  anything  that  appears  fairly  white  on  the 
plate  at  the  end  of  development  will  be  absolutely  transparent  on  the 
finished  plate  and  quite  black  on  the  print,  if  the  remainder  of  the  plate 
has  good  density.  The  ideal  x-ray  picture  is  one  in  which  the  lights 
are  white  and  the  shadows  black.  To  accomplish  this  the  tube  must  have 


^rfh  MKD1CAL    KI.KCTHiriTY    AND    KONTliKX    KAYS 

the  right  degree  of  vacuum  and  must  give  a  sufficient  intensity  and  have 
a  degree  of  penetration  which  passes  through  the  soft  pai'ts,  but  casts 
a  deep  shadow  of  the  bones,  and,  of  course,  the  exposure  to  the  .r-ray 
must  be  of  sufficient  duration,  (liven  these  coin  lit  ions,  the  development 
should  be  carried  on  until  the  darker  parts  of  the  plate  are  opaque  to 
transmitted  light  and.  therefore,  have  the  requisite  density,  but  should 
usually  not  be  carried  far  enough  to  completely  wipe  out  1  he  visible  image 


P  4  ? 


on   the   plate.      Determining  the  density  of  flu-  plate   by   holding  it    up 

i'ii    the  operator  ;ind   the   liulii    and   looking  ;,t    il    b\-   transmitted 

le  \\  it  h  .r-rn  v  pi  a  1  <•-.  \\'hi'jli  a  re  a  t'fect  ei  1  1  >v  expo- lire  to 

•^hoi'l    i  |e\'elopnient    i<    required    to    -ho\\'    the   soft    pai'ts 

-    \\cll   as   the   bones.        I  he   lotmc-t    development    is 

md   peh'is  and   hip-joint.  :md   in   1  he>e  ca.-es  the 

•:     on    the   plate   a-    to   -ho\v    practically    wliile 

'    •       vords.   \\  it  h  a   pelvic  pict  ure  -ome  p;i  rl  s  of   1  he 


Tin-;  .r-K.\Y  877 

plate  have  boon  very  slightly  acted  upon  by  the  a;-rav,  which  has  had 
to  penetrate  (i  or  S  inches  or  more  of  flesh  and  bone,  whereas  other 
parts  have1  received  the  direct  rays  from  the  tube1,  or  rays  only  slightly 
impeded  by  passing  through  an  inch  or  t  \vo  of  fle'sh  at  the  outer  limits 
of  the  body.  During  the  full  development  reeiuircd  lo  bring  into  view 
the  faint  image  impressed  by  the  denser  parts  of  the  body,  the  other 
portions  of  the  plate-  darken  up  by  rece'iving  what -amounts  to  over- 
development,  and  thus,  in  the  finished  picture  of  the  hip-joint,  for 
example1,  t  he  flesh  forms  a  slight  ly  s  ha  <  led  part  of  the;  gone-ral  background. 
'Die  real  picture1  in  this  particular  case'  is  formed  of  the  bones  alone. 

.c-Ray  films  up  to  S  x  10  inches  are  easily  developed  in  a  flat  tray 
by  clamping  the'  author's  film  clip  to  one  e'nd.  And  two  S  x  10  films, 
either  single  e>r  elupliti/od,  can  be  developed  in  the  same1  S  x  10  tray. 
Fhe  clips  are  to  be;  at  opposite1  ends  and  the1  se-cond  film  must  be1  thor- 
oughly wet  in  water  be-fore-  it  is  put  in  the1  developer,  so  as  not  to  stick 
to  the1  first  one1.  Frequent  changes  are  made  by  pulling  out  the  one 
underneath  ami  placing  it  on  top. 

Large1!'  films  or  a  larger  number  to  be1  dovolopoel  are  betteT  handled 
in  suitable  clip  frame's  which  enable  the-m  to  be1  hung  vertically  in  a 
tank. 

E.i'U'id  lo  Which  Development  Should  l>c  Carried. — Xo  certain  number 
of  minutes  may  be  usually  elepe'nde-d  upon,  either  for  tray-development 
with  a  strong  devele)por  or  for  lemg,  weak  tank  dove'le)pment.  Differ- 
ences in  exposure  necessitate  variations  in  the1  time1  of  development,  and, 
generally  speaking,  the  most  satisfactory  plates  of  films  are  those1  whie-h 
are1  fully  developed  in  five  or  ten  minute's  in  a  strong  developer  or  from 
one'-half  to  two  hours  with  tank  development. 

De'ntal  radiographs  upon  positive  cinematograph  film  should  lie'  de1- 
ve-lopenl  until  the  image1  is  clearly  visible  upon  the  back  of  the  film,  and 
has  begun  to  fade  upon  the1  front  it  is  nee-ossary  that  details  should  bo 
seen. 

The  cardinal  principle  is  that  where1  the  plate1  remains  perfe'ctly  white 
no  details  will  be1  founel,  nothing  but  total  transparency,  that  wheMv 
the  plate'  is  moderately  elarkonod  oveTy  detail  will  be  visible1,  and 
whore  the  plate1  is  black  the  density  will  be  so  great  that  the  plate  is 
opaque  and  details  are  lost.  The  latteT  condition  i<  commonly  seen 
upon  the1  portion  of  the  plate1  outsiele  the1  image  of  the  patient. 

The  next  part   of  the  process  consist>  in  "jiritn/''  the  image  on  the 
plate.      This  is  done  by  soaking  th"  plate  in  an 
for  about  half  an  hour:  until  five  minute's  after  all 
have   disappeared    from    the    film.      following 
washed    in   runnniL!;  water   for  about    an    hour 
chemicals,  especially  'he  hypo,  which  would  c< 


S7S  MKIMfAL    KLKCTHHTrV    AM)    HoXTCKX    RAYS 

which  prevents  softening  or  frilling  of  the  film  during  the  subsequent 
washing.  This  can  he  used  several  times,  adding  hyposulphite  of  sodium 
to  it  when  it  becomes  exhausted. 

The  plate  should  be  carefully  washed  off,  using  the  finger-tips  or 
a  verv  soft  sponge  to  remove  particles  of  sediment  from  the  film  surface, 
and  real  rubbing  to  remove  a  tough  black  film  which  is  found  in  spots 
near  the  edires  of  the  glass  or  back  surface.  Then  the  plate  is  set  in  a 
drying  rack  in  a  place  where  dust  will  not  be  likely  to  catch  upon  the 
moist  gelatin  surface  of  the  film. 

If  a  koiluf:  or  similar  celluloid  film  is  used  the  process  of  development 
is  the  same,  but  at  the  end  a  counle  of  pins  are  stuck  through  the  corners 
and  the  film  hung  up  to  dry. 

In  any  ca.-e  the  r.ra.v.s-  of  moisture  had  better  be  wiped  off  before  the 
film  surface  has  begun  to  dry.  Tear  drops  on  the  plate  and  a  line  of 
water  at  the  bottom  of  the  plate  make  the  film  dry  more  slowly  and 
rau.-e  darker  areas  in  those  places. 

The  chemistry  of  photography  is  interesting.  The  dry  plates  or 
celluloid  films  are  coated  with  a  gelatin  or  other  emulsion  containing 
nitrate  and  bromid  of  silver,  and  when  this  is  acted  upon  by  light  the 
.-ilver  compounds  become  more  easily  acted  upon  by  agents  which  seek 
oxygen.  The  developing  solutions  contain  such  agents  and  on  the 
portions  of  the  plate  acted  upon  by  light  metallic  silver  is  deposited  by 
the  abstraction  of  oxygen  from  the  original  chemic  compounds.  This 
produces  a  visible  image,  whereas  none  was  to  be  seen  when  the  plate 
was  first  looked  at  in  the  dark  room  after  exposure  either  to  light  or 
to  the  .r-ray.  But  this  image  has  to  be  made  permanent  by  the  process 
of  fixing,  which  consists  in  soaking  in  a  solution  containing  hyposulphite 
of  sodium;  this  dissolves  away  all  the  unchanged  silver  compounds. 

The  choice  of  developers  is  important.  The  old  standard  developing 
agent  is  pyrogallic  acid,  and  probably  one  can  make  a  greater  number 
of  good  plates  with  all  sorts  of  normal  or  under-  or  overexposures  by  its 
tise  than  with  any  other.  It  makes  a  brownish  colored  plate  which 
prints  better  than  the  black  or  gray  plates  produced  by  most  other 
developers.  About  the  only  objections  to  it  are  the  facts  that  it  stains 
the  hands  badly  and  that  it  cannot  be  used  for  developing  the  print  also. 

A  good  formula  for  a  pi/ro  dcrcloptr  is 


Water 

Ifi  ounces 

Pvroirallic  ncid 

1  ounce 

Ox'dic    arii  1 

1  0  grains 

Water                                    

](')  ounces 

I)ri'jil  sulphite  of   sodium      

,,       .. 

\Vat.-r.  . 

.    Hi  ounces 

I  tried  carbonate  of  sodium    2 

Use  Solution  A,  1  ox.;  Solution  B.I  ox.;  Solution  (',  1  ox.;  water,  7  ox. 
I)evlopini:  factor  12. 

By  "  ili  i-ilo/n'/n/  fat-tor  J,.'"  we  mean  that  if  we  note  the  time  from 
placing  the  phite  in  the  developer  until  the  appearance  of  the  image 
and  multiply  that  time  by  12  we  shall  have  the  time  required  for 
complete  development.  With  this  developer  a  normal  exposure  will 
.-how  an  linage  in  twenty  to  forty  seconds  and,  consequently,  only  two 
to  four  minutes'  development  would  be  required.  If  an  image  (Iocs  not 
show  at  all  after  a  minute  or  so  the  plate  has  been  underexposed,  and 


THK    .C-KAY 


S70 


it  may  be  wise  to  pour  off  the  developer  and  treat  the  plate  as  we  would 
have  if  we  had  known  beforehand  that  it  was  underexposed. 

For  a  known  underexposure  an  excellent  way  is  to  use  the  soda 
solution  alone  at  first:  Solution  H.  1  ox;.;  solution  (',  1  ox.;  water,  7 
07,.;  allow  the  plate  to  remain  in  this  for  about  half  an  hour,  then  pour 
the  solution  off  and  add  to  it  solution  A,  1  ox..,  and  use  the  complete 
mixture  for  ten  minutes.  At  first  an  image  becomes  visible  from  the 
action  of  the  soda  solution,  but  it  is  faint  and  soon  disappears,  the 
entire  plate  blackening  up.  During  the  rest  of  the  process  the  plate 
is  just  black  all  over  and  it  is  not  until  after  it  is  removed  from  the  hypo, 
and  can  be  examined  by  looking  through  the  plate  in  ordinary  daylight, 
that  the  image  can  be  seen.  It  may  then  be  found  to  be  very  good 
indeed  and  may  make  an  excellent  print.  Generally  speaking,  the  pyro 
makes  density  and  the  soda  detail,  and  if  the  complete  developer  were 
used  for  the  length  of  time  required  to  produce  a  good  image  with 
underexposure  the  pyro  would  make  the  plate  too  dense  all  over  or 
fog  it. 

The  term  fo</  is  used  to  designate  a  universal  or  localized  increase  in 
density  of  the  plate,  produced  by  extraneous  causes  and  obliterating 
the  natural  lights  and  shadows  of  the  picture.  Fog  may  be  produced 
in  an  .r-ray  plate  by  allowing  the  plate  to  become  light  struck,  for 
instance,  by  keeping  the  plates  in  too  bright  a  light,  which  may  penetrate 
even  the  black  and  orange  envelopes  in  which  .r-ray  plates  are  usually 
kept,  or  by  white  light  entering  the  dark  room,  or  by  too  much  exposure 
to  ruby  light  during  development,  or  by  accidental  exposure  to  the  .r-ray 


556.  —  Tank  development. 


at  some  other  time  than  when  the  picture  was  being  made.  Chemic 
fog  may  be  caused  by  adding  new  or  strong  developer  to  that  in  which 
the  plate  already  is,  thus  subjecting  the  plate  to  the  action  of  an  imper- 
fectly mixed  developer;  or,  as  intimated  above,  by  development  with 
too  strong  a  developer. 

Another  way  with  underexposed  plates  is  to  use  a  very  weak  devel- 
oper for  a  very  long  time,  as  in  "tank  development."  In  this  process  the 
plates  are  placed  in  vertical  grooves  in  a  hard  rubber  or  nickel  tank 
(Fig.  550),  filled  with  a  developer  of  about  ^  the  normal  strength  and 


MKDH'AI.     KI.KCTRK'ITY    AND    H(").\T(iK\     HAY: 


containing  potassium  or  ammonium  bromid.  to  act  as  a  further 
re-trainer,  and  the  plate  i<  left  soaking  in  it  for  seven  to  twelve  hours. 
The  same  proees-  give--  excellent  results  as  to  details  in  cases  of  normal 
or  overexposure  if  one  has  time  to  wait  for  the  result.-.  .For  a  normal 
exposure  about  two  and  a  half  hours  and  for  an  overexposure  about 
an  hour  would  be  approximately  the  time  required  for  lank  develop- 
ment. But  in  the  case  of  normal  and  overexpo.-ure  the  plate  must  be 
looked  at  from  time  to  time  and  the  process  brought  to  a  close  when 
the  plate  is  completely  developed.  Remember  in  every  case  that 
there  is  very  little  to  be  lost  bv  keeping  the  plate  in  the  developer  too 
long,  and  there  i-  everything  to  be  lost  by  taking  it  out  beiore  the  plate 
has  gained  sullicieiit  density.  In  some  cases  development  is  not  com- 
plete until  the  original  white  image  at  first  produced  has  almost  faded 
out.  An  overdeveloped  plate  will  still  make  an  excellent  print,  while 
one  underdeveloped  is  worthless.  The  fadintr  out  of  the  image  during 
development  does  not  imply  tnat  it  is  actually  disappearing. 

(  >ne  very  good  guide  in  developing  all  single-coated  plates  ami  films 
i-  fhe  presence  of  an  image  on  the  back  of  the  plate.  This  usually 
.-hows  complete  development. 

Tank  Developing. — A  good  formula  for  this  purpose  i-  the  following: 

Stork  Snlutntt, 

Water 

(  ';ir! )'  unif  i  if  si  ii  ii'liii     'irii-'i; 

S'll)  'iiitr  of   soi  iililll      <il'i(".l ; 

1  !n  itnii  1  of  :i  minonium 

I  'ii  ric  aci-i    

I 1  v.  In  H  i.i  im  PHI- 


Dissolve  the  intrredient s  in   the  <riven  order  and  keep  tlie  complete 

M   1X1    ,:•     :i,   (')-<;'/..  bottle.-,   full  ali«!   tightly  corked. 

\  >:}'  usi    m  developing   a  number  of  s  •   Pi-inch   plates  take  0  o/.  oi 
i  hi.-  -lock  solution  and  10  pints  of  water,  fillmtr'  the  tank. 

i:    :    •  rse  tlie  plates  HI  cool  water  before  putting  them  m  the  tank. 

•the]          ij  nek   up-and-down   moiion   •.'.','<  i    placing    m    ihe  lank  to 

:    bells.      Take  them  out   of  the  tank  after  a  few  minute-  and 

'•    fii'-n    po.-ition;    thi.-    i-    to   prevent    streak-   from    the  solution 

beinir  po--ibl\-  -i  ron  tier  at   1  he  bo  t  torn  of  the  tank.      (  tccasionallv  rock- 

'nitr  :'  i-  of  u'reat  service  in  preventing  spot-  and  -ti'eaks. 

Si  '.  •  ral    plate-    of    the    same    or    of    dilVeretit    si/e-    ma\"    be    develoJK'd 

in    I  hi     lank   al    the  same   time.      A   cover   i-   placed   over  it.  -o  that   the 

ii    kept  dark  diiriuti  the  entire  time,  but  only  from  time 

'-'  '  e  i  :    more  ot   the  plate-  are  ready   to  be  taken  Ironi  the 

• '    :   ;  •  1 1  placed  in  the  hy  |  K  i. 

I    '        . '    t  ho  o    _    l\  in  tank  developn  lent  lor  instant  a  neons  exposures 
1  -    t  he  plate  may  be  de.-cribed  a-  underexjio-cd  and 
•  rable  number  o|   plate-  are  to  be  developed  on  the 
. 

•  I  >'    •  fur  /•"/////*.-    Kadi  film  maybe  fastened  by  ciani]).- 

a  '.'.Me  frame.      'I  he  him-  are  put   m  a  rack  and  im- 

mer-i  ;,,  \\et    i  he  films  thoroughly  and  then  set   in  the 

di  vi  .  ,,.  of  developer.      Thi-  mu-t    all  be  done  in  the  dark 


SSI 


room  by  red  lijiht,  bu'i  alter  the  cover  has  been  put  on  the  t;ink  the 
operator  may  open  the  dark  room  and  then  leave  the  films  for  about 
the  time  required  for  normal  exposures  if  one  is  sure  of  uniformity  as 
to  the  exposure.  The  fixing  takes  about  fifteen  minutes  and  then  water 
may  be  allowed  to  run  through  the  tank  for  half  an  hour.  This  removes 
the  hypo  from  both  the  films  and  the  tank.  A  nickel-plated  tank  may 
be  used  for  all  three  of  these  processes,  whereas  a  zinc  tank  could  not  be 
used  for  the  hypo;  this  solution  acts  upon  zinc. 


witse  Compartments 
iSmches  land,  inside 


Fij:.  o.~>7. — Paragon  stone  developing  tank.      (Gen.  \Y.  Brady  iV  Co.,  Chicago.) 


"All  tank  developers  which  are  to  be  kept  for  any  length  of  time 
must  be  covered,  to  prevent  oxidation,  either  with  a  floating  lid  or  a 
piece  of  paraffin  paper  cut  to  the  exact  size  of  the  tank  and  floated  on 
the  solution.''  (Kastman  Kodak  Co.). 

The  M.  Q.  Developer. — The  inetol  hydroqtiinone  developer  has 
conn-  into  verv  genera!  use  for  developing  dry  plates  ami  celluloid  films 
and  also  for  velox  and  bromid  paper  and  similar  print-.  Jt  is  easy 
tn  handle,  does  not  stain  ihe  finders  badly,  and  jjjves  a  clear  black  plate 
whirh  is  very  hand-ome  and  which  has  almost  as  uood  printing  qualities, 
as  one  developed  by  pyro.  Its  disadvantages  are  i  he  slowness  with 
which  i'  acts,  and  the  ji'nui.ter  difficulty  of  exactly  regul  at  ing  the  develoj)- 
nicnl  to  tret  the  best  results  out  of  different  plate.-  with  all  sorts  of 
exposures.  It  is  stild  everywhere  in  tubes,  each  <n  \vlncli  contains 
enoii'-i'h  to  make  s  ounces  of  developer  bv  simply  dissolving  in  water. 
For  a  normal  exposure  the-  plate  should  be  developed  lor  fifteen  or 
twenty  or  thirty  minutes  in  a  fresh  developer.  If  the  inia^c  lla.-lu-s 
up  and  the  plate  seems  to  be  overexposed  either  promptly  add  •">  or 
10  drops  of  a  10  per  cent,  solution  of  bromid  of  potash  as  a  restrainer, 
or  else  pour  off  the  developer  and  use  an  old  and  partly  exhausted 
developer.  If  no  i  ma  ire  is  visible  in  five  or  ten  minutes  the  plate  lias 
been  underexposed  and  is  iroiim1  to  require  prolonged  development  in  a 
weakened  developer.  An  ordinary  hip-joint  picture  requires  about, 
one  hour'.-  development  in  M .  (.,).  developer  \\hich  is  not  entirely  new. 
A  picture  o|  the  Toot  would  require  about  halt  an  hour's  development. 
Mo-;  of  the  radiographs  in  t  his  book  were  developed  with  M.  ( ).  developer 
in  a  simple  ilat  tray,  and  probably  it  will  be  found  be-t  to  use  this  as  ;i 
starting  point,  and  then  to  add  the  tank  development  and  th<'  soda 
followed  by  pyro  development  as  one's  ireneral  technic  improves. 


882  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

Other  good  developers  are: 

Kiknnoqen-hydroquinone 

A. — Water                                                               4S  oxincos 

Sulphite  nf  sniliuin  dried) 2 

F.ikoiio<rcn   -40  grains 

Hydroquinone 00 

H.  —  Water 10  ounces 

('arlionate  of  sodium  i  dried) 2      " 

I'se  .t.  '••'>  ounces;    li,   1  ounce.      Factor  12. 

Ortol 

A.      Water 24  ounces 

Potassium  metabisulphite 00  Drains 

Ortol 1X0      " 

I'se  e(|ual  parts  of  A  and  B.      Factor  11. 

These  are  practically  the  same  as  recommended  by  the  M.  A.  Seed 
Dry  Plate  Company,  Si.  Louis.  Missouri. 


The  special  advantage  claimed  for  pyrocatechin  is  that  it  can  be 
used  in  cases  requiring  prolonged  development  without  fogging  the 
plate. 

Eastman  x-ray  developing  powders  are  a  groat  convenience.  They 
have  -imply  to  be  dissolved  in  water  and  have  much  the  same  properties 
as  metal  hydrochinon. 

A  developer  containing  only  hydrochinon  as  its  active1  agent  quickly 
affects  the  surface,  and  with  it  the  striking  through  of  the  image  should 
not  be  wailed  for.  but  simply  the  density.  Such  a  developer  may  be 
cheaply  and  desirably  made  bv  using  1  ounce  of  caustic  soda  to  each 
Ballon  of  developer  as  a  substitute  for  the  carbonate  of  potash  called 
for  by  most  formula1.  With  this  developer  very  little  loss  of  density 
occurs  in  fixing. 

The  Titubator.  This  is  a  useful  apparatus  in  which  the  plate  in  a 
tray  lull  of  developer  is  placed  in  a  light-proof  box  and  by  an  electric 
motor  i.-  subjected  to  the  gentle  rocking  required.  The  plate  must  be 
placed  in  the  titubator  in  the  dark  room,  but  the  tlurtv  minutes  or  ,-o  of 
locking  IJKIV  be  done  by  the  closed  machine  in  anv  ordinary  light. 

The  Influence  of  the  ./--Ray  Upon  Plates  During  Development. — 
'I  lie  r-ray  .-hould  not  be  m  ope  rat  ion  in  t  he  .-a  me  room  or  in  an  adjoining 
loom.  An  ordmarv  lath  and  plaster  partition  is  perfectly  transparent 
io  the  .r-ray  and  during  the  prolonged  development ,  so  often  required 

./•-ray   plates,  they   would   be  sure  to  be  fogged.      The  same   is   true 

eve]     .;   iho  plates  ;iro  111  sheet    iron   (galvanized  or  tinned  or  japanned) 

,  but  ,i  the  developing  t  rays,  are  com j) let  eiy  .-ur rounded  by  a  box  of 

r-ray   mHid.   lead  and  tin.  the   plates  are  .-nfo.     The  protection  should 

be  ;,!   top,  bottom,  and  -ides.;  but.  of  course,  it   is  understood  that  even 


THE    3XRAY 


883 


with  tliis  it  would  not  do  to  allow  the  x-ray  to  shine  directly  upon  it 
at  short  range. 

Making  Prints  from  x-Ray  Plates. — The  print  is  the  finished  pic- 
ture on  paper.  It  is  made  by  placing  the  film  side  of  the  paper  in 
contact  with  the  film  side  of  the  plate,  allowing  ordinary  light  to  shine 
through  the  plate,  the  varying  density  of  different  parts  of  the  plate 
producing  the  lights  and  shadows  of  the  picture  on  the  sensitized  sur- 
face of  the  paper.  In  the  case  of  Solio  and  other  printing-out  paper  the 
image  is  visible  upon  the  paper  before  any  further  treatment  is  given 
to  it,  and  the  printing,  or  exposure  to  light,  is  continued  until  the  print 
is  dark  enough.  The  printing  frame  opens  in  sections,  so  that  one  part 
of  the  print  may  be  inspected  from  time  to  time  without  disturbing  the 
relative  position  of  the  paper  and  the  plate;  just  like  opening  a  book 
and  closing  it  again.  These  papers  require  brilliant  daylight  and  take 
from  a  few  seconds  to  half  an  hour  or  more  to  print,  depending  upon 
the  density  of  the  plate.  They  may  be  made  by  the  electric  arc  light, 


but  not  bv  the  incandescent  light.     The  print  should  bo  made  several 


shades  darker  than  vou  wish  it   to  finallv  appeal1,  as  it    fades  to  some 


extent  in  the  different  solutions.      It  is  first  washed  in  five  or  six  chang< 


of  water  to  remove  t  he  unchanged  silver  and  then  placed  in  the 


Bicarbonate  of  sodium  sufficient  to  produce  a  neutral  reliction 


The  print  should  tone  in  about  six  or  seven  minutes,  during  which 
time  a  cheinic  change  lakes  place  in  the  film  whereby  a  deposit  of 
metallic  irold  takes  the  place  of  the  silver  compound  on  the  surface  ot 
the  paper.  At  the  same  time  the  color  of  the  picture  changes  from 


884 

reddish  to  a  rich  purplish  In-own.     Failure  to  produce  this  change  in 
color   would   indicate  a   worthless   toning  solution. 

The  print  is  then  washed  in  water  and  placet  1  for  twenty  minutes 
in  the  acid  hypo,  where  the  image  is  made  permanent  and  the  film 
hardened.  The  formula  for  this  is  almost  the  same  as  the  one  recom- 
mended ft  a1  fixing  ]  ilates. 

Ariii   If.'//"'  /or  >•„//„    Print* 

Hyposulphite  of  sodium    (i     ounces 

Alum    crystals  •_", 

Sulphite  oi'  -odium    crystals! .  .  ^  ounce 

Water .^ .    7(1     ounces. 

All  traces  of  the  hypo  should  be  removed  by  washing  for  an  hour  in 
runnim:  water. 

Print*  M'ldcfrnm  Pluto*  or  Film*  1T///V/,  Art  N/ '//  ir(/._it  isoccasion- 
ally  desirable  to  obtain  a  print  at  once  without  waiting  for  hours  while 
the  plate  or  film  dries.  While  the  sensitized  surface  is  still  perfectly  wet 
a  sheet  of  photographic  paper,  also  wet,  is  laid  upon  it.  The  two  sen- 
sitized surface^  are  face  to  face  and  gentle  pressure  i-  made  to  squeeze 
out  any  bubbles  of  air  which  may  be  trapped  between  them.  The  print 
is  made  in  the  usual  manner,  but  is  not  quite  so  clear  as  if  made  with 
dry  paper  and  a  dried  film  or  plate.  The  plate  or  film  is  not  injured  if 
this  is  carefully  done. 

In  niftuntiiifi  print*  on  cardboard  the  first  thinir  is  to  dry  the  prints 
nnd  trim  them,  then  wet  them  and  pile  them  one  rni  top  of  the  other 
face  down  on  a  sheet  of  glass.  Squeeze  out  the  excess  of  \vater  by 
means  of  a  piece  of  blotting-paper  and  a  print  roller.  Cover  the  back 
of  the  Topmost  print  with  photo  paste,  lift  up  the  print  by  two  opposite 
corners,  and  phu-e  it  in  position  upon  the  card  and  rub  it  down  smoothly 
with  th"  print  roller. 

Yelox   paper  and  other  similar  papers  require  only  a   few  seconds' 
exposure'  to  gas  or  electric  lidit    at    a  distance  equal   to  one  and  a  half 
tun"-  the  diagonal  measurement  of  the  plate.      \o  image  is  perceptible 
(111!    I    the  paper   has   been    placed    m    the   developer   and.    hence     these  are 
.  'ofii nij-r>iit  papers.       The   M.  Q.  devi  !oper  used   for  developing 
;  . . .,  excellent   i'e-i  ;'  -  "with  the.-e  pa ]i"'.>  .  'id  i  he  same  acid  hvpo 
•       .   ion   may  be  used.      It!   USUIL;   i li.-1     papers   i!    i-  necessary  to 
.    •-         •  •': .!  with  -1!!'-  of  paper  \\\\     •  me  of  exposure  to  be 

!.    the  i  \posure  i-  too  long  the  paper  blacken-  u]i  in  the  devel- 
e!  ail  i      llie  ]  lid  lire  is  lost .       [f  the  t      posiire  i-  too  sh<  H't  no 
:    ie    in    the    '  leveloj  iel'   will    ]  i!'<  idlice    a    '^  M  ><  1    1  il'illt  . 

•    handled  in  i  he  sa  me  \'  a  v  as  \  ••!(  ix.  but  ai'e  mu"h 
e:.-i  in    a:    1,   hence    print    in  a  much  shorter  tune  of  exposure. 
in  making  prim  'TV  large  ]  ila  les  1  iccause 

;   gradually    vvlule   the\    are    m    i  he   developer,   more 
• .  I  of  flashin      .  e  like  the  image  on 

!  '     i  -.    I  lie!  et'i  ,1-f.    easier    to    - U  e    a     perfect     print  . 

:  '  -   it    i-   liece--,  ollli'lllv  before 

1     •    •  and  then  to  set    i  hai   1  he  d<  velo]  .<  r  iiist  an!  ly 

<•<,    i-    -     all     |  tail  -    of    the     prii   !  ,    ot  hel  V\  ise    the    pl'ilit    Will 

ii'    darker    or    linhier    coloi    shoeing    uneven 

1UU.-1     be    iaken    oul     oj     I  he      ie\  e]o|  ier    at     jllst 

!     1  inn    -lioui1     In     I'll     ed   ni   wal  er  belol'o 


SS5 

placing  in  llic  acid  hypo.  The  paper  should  not  he  creased  and  crum- 
pled, as  this  will  he  sure  to  cause  a  separation  of  the  sensitive  film  or 
coating  and  the  formation  of  blisters.  These  also  result  from  letting 
a  st  ream  of  water  st  r ike  directly  on  t  he  film  surface  and.  especiallv,  from 
putting  the  print  into  water  or  solutions  which  present  too  great  a 
difference  of  tempera! ure. 

The  process  of  making  and  developing  all  except  hromid  prints  may 
he  carried  on  hy  ordinary  light  in  quite  a  darkened  room. 

In  making  a  print  from  ti  lunji  /tlti/r  it  will  sometimes  happen  that 
one  part  o|  the  plate  is  thinner  and  prints  more  rapidly  than  another, 
and  in  such  a  case  the  thinner  part  should  he  held  further  from  the  light 
or  else  covered  up  during  part  of  the  exposure.  If  covered  it  must  he 
by  some  object  which  is  kept  in  constant  motion  to  prevent  a  line  of 
demarcat  ion. 

1'i'i  nlinij  from  a  Thin  Plate. — Where  the  details  in  a  thin  and  almost 
transparent  part  of  the  plate  are  desired  the  print  should  be  a  light  one. 
The  ordinary  length  of  exposure  to  light  in  making  the  print  would 
make  all  this  part  simply  a  black  mass. 

Ili'iimiil  Print*  Directly  from  the  Patient.- — P>y  this  method  a  finished 
paper  print  is  made  inside  of  five  minutes.  One  or  more  sheets  of 
bromid  paper  are  placed  inside  a  light-proof  envelope  and  u>ed  exactly 
like  a  plat !•  in  taking  an  .r-ray  picture.  The  paper  is,  developed  just 
like  an  ordinary  bromid  print,  but  shows  the  bones  white,  the  ilesh 
whitish,  and  the  background  gray  or  black.  'The  process  is  one  that 
does  not  require  a  dark  room  and  saves  a  very  great  deal  of  time.  You 
get  a  print  in  five  minutes  as  against  about  twenty-four  hours  by  the 
plate  method.  This  is  much  sooner  than  even  a  wet  and  only  partially 
finished  plate  would  be  read}'  for  examination.  It  is  useful,  for  instance, 
in  examinations  for  a  needle  in  the1  hand  or  for  a  fracture  about  the  hand. 
In  these  cases  a  fluoroscopic  examination  often  fails  while  the  picture 
succeeds.  Then  again,  the  picture  can  be  examined  and  discussed 
ad  libitum,  whereas  a  con.-ultation  while  examining  with  the  .r-ray  is  a 
source  of  very  great  danger  from  too  long  exposure.  With  a  Ii2-inch  in- 
duction-coil and  a  primary  current  of  !^  amperes  (intensity  Xo.  15 
Tousey,  penetration  Xo.  (>  Benoist),  a  picture  of  the  hand  by  this 
method  would  require  an  exposure  of  about  twenty-live  seconds. 
Such  a  picture  taken  at  a  meeting  of  the  .Middlesex  County  Medical 
Society  of  Xew  Jersey  showed  the  barb  of  a  fish  hook  which  had 
been  in  a  doctor'.;  finger  for  thirty  years.  'The  method  is  especially 
available  for  the  extremities  and  for  dental  skiagraphy.  The  best, 
result-  are  obtained  with  exposures  two  or  three  times  as  long  as  are 
required  for  a  plate,  and  this  makes  it  less  useful  for  the  thicker  portions 
of  the  body. 

Plastic  radiographs  are  prints  to  which  an  artificial  appearance 
of  perspective  is  given.  A  process  was  suggested  by  Alexander  and 
perfected  by  Schellenberg.  It  consists,  essentially,  in  making  a  radio- 
graph upon  a  single  photographic  plate,  then  making  a  print  from  this 
on  a  transparent  film.  The  finished  print  is  made  from  both  plate  and 
the  transparent  positive  film,  placed  one  on  top  of  the  other,  but  not 
exactly  coincident.  A  very  simple  and  easy  process  is  to  use  what  is 
technically  called  bromid  imjntirc  pn/xr  for  the  first  positive  print  from 
the  original  plate.  This  paper,  after  development .  is  rendered  trans- 
parent bv  i m niers ion  in  an  oil v  substance,  and  can  t  hen  he  laid  upon  the 


SM>  MKDICAL    KLK<  TKICITY    AND    RONTGEN    RAYS 

original  plate  and  a  print  ran  bo  made  upon  any  ordinary  volox  or 
solio  papers.  Such  pictures  iu:iy  have1  cortain  usos,  hut  they  do  not  give 
any  true1  stereoscopic  effort. 

Alexander's  M<tli<><l  uf  I'laxt/e  Radiography.— Dr.  Rula  Alexander1 
(legerities  a  method  \vhirh  consists  in  making  as  good  a  negative  as 
possible  on  Plate  I.  From  this  a  diapositivo  is  made  on  Plate  II  by 
allowing  ordinary  light  to  shine  through  Plate  I  \vhilo  it  is  fare  to  faro 
with  Plate  II.  The  second  plate  is  developed  and  shows  an  image  with 
the  lights  and  shadows  reversed.  Plates  I  and  II  are  now  fastened 
together  bark  to  bark  and  with  their  images  almost  coinciding,  and  a 
diapositivo  is  made  on  Plato  III.  This  plate  gives  the  effort  of  perspec- 


Fi<_'.  •"<».       Phistic  r:iflio<rrnph  of  thf  frontn! 


f    the  face. 


tive  and  also,  it'  is  claimed,  an  increased  definition  of  the  bones  and  soft 
parts.  It  does  not  exaggerate  or  reduce  the  apparent  si/e  ot  the  bones. 
Plate  III  is  a  positive  and  if  it  is  desired  to  seen  T-e  u  print  of  the  ordinary 
kind  in  which  the  bones  appear  dark,  still  another,  Plato  IV,  must  bo 
made  from  it.  As  manv  prints  as  desired  may  be  made  from  Plate  IV. 
If  only  one  print  is  desired  it  may  be  made  instead  of  Plate  III.  Fig.  528 
j-  Mich  a  p  la.-t  ic  print  from  a  frontal  sinus  and  ethmoid  and  ant  rum  radio- 
graph. It  loo];-  a  little  like  a  picture  of  a  plast  er-of-Paris  cast,  and 
shows  that  t  he  plast  ic  met  hod  is  of  com  pa  rat  i\  "ly  little  value  in  depict  ing 
the  ethmoid  cells  and  the  antrum,  but  that  it  makes  the  frontal  sinus 
more  ron-picuoiis. 

Radiographs  of  the  extremities  are  improved  by  this  method  except 
imber  of  small  bones  are  crowded  together,  as  in  the  carpus. 

Stein-has  also  described  a  method  for  plastic  radiography. 

Precautions  to  be  Taken  in  Developing  Radiographs.  —  A  trace 
of  hypo,  remaining  ou  the  plates  or  prints,  will  make  a  brown  stain 

1  Ar<"}i.   of    t|,f.    HI,  n(  i_rcn    Kay.    .J.-muiiry,    I'.'US,    ami    several    previous   article.-    in 

Bll>l:i)»'-t  1    kiv.   OrVdX'jryi-sUli't,    I'.HII'i.   etc. 

2  Minich.  M.'-l.  \\och.,  July  :',!,  I'.XWi. 


THE    X-RAY  887 

which  will  spoil  the  whole  work.  Eternal  vigilance  must  be  used  with" 
this  and  all  the  other  chemicals.  There  must  be  a  special  tray  for 
the  hyposulphite  of  sodium  solution  and  when  through  with  it  the  solution 
must  be  filtered  back  into  its  own  bottle.  Running  water  should  be 
constantly  ready  and  the  fingers  should  be  washed  every  time  they  have 
been  in  any  of  the  chemicals.  Keep  up  a  rocking  motion  of  the  trays  in 
which  plates  or  films  are  being  developed.  Do  not  let  one  lie  on  top  of 
another,  as  that  would  scratch  it  or  prevent  the  uniform  action  of  the 
developer  on  all  parts  of  it. 

From  beginning  to  end  the  plates  and  celluloid  films  ought  never  to 
see  a  particle  of  white  light  or  of  .r-ray  except  during  the  actual  taking 
of  the  picture.  They  ought  to  be  exposed  .just  as  little  as  possible  to 
ruby  light  in  the  processes  of  placing  them  in  the  opaque  envelopes 
and  later  placing  them  in  the  developer.  While  in  the  developer  they 
ought  to  be  in  absolute  darkness,  except  for  occasional  examination  by 
the  ruby  light  to  note  the  progress  of  development. 

A  very  important  point  is  not  to  touch  the  film  surface  during  the 
different  manipulations.  A  touch  with  the  finger  is  apt  to  leave  an 
"opaque  finger  mark"  on  the  plate  which  ruins  that  particular  part  of 
it.  This  would  show  in  the  print  as  a  white  smudge. 

( lencrally  speaking,  if  a  beginner  watches  the  development  of  a 
plate  he  is  apt  to  underdevelop  it;  fearful  of  losing  the  image  altogether 
when  he  sees  it  begin  to  fade  out  upon  the  surface  of  the  plate.  This 
fading  simply  means  that  that  portion  of  the  plate  also  is  beginning  to 
be  developed  as  well  as  the  background  which  was  directly  exposed 
to  the  .r-ray.  Tf  this  is  stopped  much  too  soon,  of  course,  you  fail  to 
get  any  detail  in  the  picture,  and  may  hardly  see  the  bones  in  the  flat 
appearing  image  of  the  flesh.  If  the  development  is  stopped  only  a 
little  too  soon  you  may  get  a  plate  with  good  detail,  but  so  thin  and 
transparent  that  it  makes  a  very  faint  print.  On  the  other  hand,  a 
little  overdevelopment  does  no  harm  at  all,  it  simply  means  that  you 
have  to  hold  the  finished  plate  up  toward  a  bright  light  to  see  the  image, 
the  print  made  from  it  is  perfect.  A  plate  very  much  overdeveloped  is 
almost  jet  black  and  opaque,  and  must  be  held  up  to  a  very  powerful 
light,  like  the  Cooper  Hewitt  light,  in  order  to  seethe  image;  and  a  print 
from  it  shows  only  th,e  bones.  The  flesh  and  even  thinner  portions  of 
bone  may  not  show  at  all  in  a  print  from  such  a  plate.  The  print  is 
also  a  harsh  black  and  white. 

Restraining  the  Development. — A  plate  on  which  the  image 
flashes  up  almost  immediately  when  it  is  put  in  the  developer  has 
usually  Ixvn  overexposed,  and  if  developed  in  the  ordinary  way  soon 
turns  black  and  will  be  so  dense  that  the  picture  can  hardly  be  seen  at 
all.  Such  a  plate  would  take  a  very  long  time  to  make  even  a  poor 
print  from;  and  it  could  not  be  studied  by  transmitted  light  unless  one 
had  a  very  powerful  electric  lamp.  One  may  know  from  the  length 
and  strength  of  exposure  to  the  .r-ray  that  the  plate  is  overexposed. 
In  case  this  fact  is  only  discovered  when  developing  the  plate  the  latter 
may  be  quickly  transferred  to  plain  water  and  then  developed  in  an  old 
developer  weakened  by  previous  use,  or  in  a  developer  weakened  by 
dilution  with  water.  Another  method  is  to  quickly  add  ''  Hestrainer" 
to  the  developer.  Tin;  restrainer  is  a  few  drops  of  a  10  per  cent, 
solution  of  bromid  of  potassium. 


MKDICAI.    KI.K(TKIC!TY    AM)    HOXTCEN     !;AYS 

Hie  (ilijcct  in  restraining  the  development  of  a  plate  is  to  obtain 
sufficient  detail  without  excessive  density.  The  details  depend  Upon 
slight  differences  in  densitv  which  call  onlv  he  brought  out  by  .-lo\V 
'  [eVelo]  illlelit  alld  llloi  lel'ate  .  lellsitV. 

A  plate  \\hich  is  known  to  he  overexposed  is  developed  from  the 
start  in  i  >ld  or  dilute  developer  or  one  to  which  rest  rai ner  has  heen  added. 

Overexposed  Plates  Which  Should  Not  Be  Restrained. —  liadio- 
Liraph.s  (it  th"  head,  abdomen,  or  hip  are  usuallv  overe\j)osed  at 
il^e-.  where  the  .''-ray  shines  directly  on  the  plate,  but  1  he  central 
nt  part  of  the  plate  is  underexposed  rather  than 
development  should  not  be  restrained,  but  the  loss 
dges.  o[  thf  p  let  lire  should  be  accepted  as  a  necessarv 
ases  the  oveivxposure  at  the  edges  is  -o  great  as  almost 
t<i  wipe  out  even  the  linage  of  the  sheet  lead  number-  laid  on  the  plate 
for  identification.  Though  these  may  not  be  seen  in  the  print  they  are 
always  traceable  when  such  a  plate  is  examined  by  transmitted  light. 
The  central  part  of  such  a  plate  may  come  up  nicely  with  normal  de- 
velopment or  it  may  require  to  be  treated  as  an  underexposed  plate. 

Full  Development  and  Subsequent  Reduction  of  Overexposed 
Plates. — This  \\-ill  often  result  in  a  beautiful  plate,  with  detail  and  con- 
trast.  when  from  accident  or  design  the  plate  is  overexposed.  In  the 
words  of  an  expert  friend  of  the  author,  "if  a  plate  flashes  right  up  leave 
it  in  the  developer  and  forget  it  for  fifteen  minutes."  The  result  is  a 
completely  blackened  plate  which,  when  it  comes  out  of  the  hypo,  may  be 
reduced  by  immersion  for  from  five  to  fifteen  minutes  in  a  weak  solution 
of  permanganate  of  potassium  and  sulphuric  acid  and  then  washing  in 
water.  If  the  plate  has  a  yellow  stain,  this  may  be  removed  by  im- 
mersion in  a  solution  of  citric  acid  and  sodium  sulphite. 

Development  of  Underexposed  Plates. —  If  there  is  only  slight 
underexposure  the  development  may  be  simply  forced.  A  full  strength 
and  entirely  new  developer  may  be  used  and  the  development  continued 
for  a  longer  time  than  usual.  Care  must  be  used  not  to  carry  this 
process  to  excess  or  the  plate  will  be  badly  fogged. 

Forced  Development. —  In  developing  ./--ray  plates  or  films  it  is  at 
times  necessary  to  force  the  plate  in  developing.  'I  he  following  formula, 
used  by  t  he  II .  X.  Tiemanii  ( 'o.  for  many  years,  gives  a  good  black  tone, 
and  enables  one  to  force  a  plate  for  a  half  to  three-quarters  of  an  hour 
before  it  will  stain  or  fog.  Dissolve: 


L'  >!r   n      hyilr'ifhinnn. 

1  .Ir   i 

1)     •  -  ounces  of  di-till;-'!  water,  hot;  then  add  to  the  sodas.     We 

-olution;  u.-c  full  -trcnuth  aiti-r  coolniir. 

d  und<  rexpo-ure  requires  long  and  s|< ,\\  development  in  a  weak 

flev'i  ntil    the   dei;iil~  are   brought    out    and   then   forcing.      Tank 

'••;<>:!<  nt   in  tin-  ca.se.  and  so  i-  the  process  bv  which  the 

pla'e  efserl   in   the  -odium   -ulphite  solution   for  several  minutes 


THE    .r-RAY  880 

nnd  then  in  the  pyro  solution.  In  spite  of  all  this  manipulation  the 
finished  plate  may  he  found  too  thin  or  the  image  too  faint  :  and  intensi- 
fieat  ion  may  he  resorted  to. 

Development  of  Screen  Plates.-  Radiographs  made  with  an  intensi- 
fying screen  are  more  like  ordinary  photographs,  and  a  special  develop- 
in. u'  formula  is  given  on  page  SOS. 

Intensifying  x-Ray  Negatives.-  This  process  may  he  applied  to  a 
plate  or  film  at  any  time  after  complete  development  and  either  hefore 
or  after  drying.  The  usual  method  is  to  immerse  the  plate  in  an  inten- 
sifying solution,  such  as 

220  grains 


until  the  entire  plate  has  turned  white,  and  the  picture  shows  upon  it 
like  a  positive.  The  longer  the  plate  is  left  in  the  intensifier  the  denser 
l  he  negat  ive  will  be. 

The  next  step  is  to  wash  the  plate  in  running  water  for  about  half 
an  hour. 

Then  the  plate  is  immersed  in 

ilpl'iiir    -  .    1  ?,  ounces 


Until  it  has  all  turned  perfectly  black. 

A  final  washing  in  running  water  completes  the  process. 

Yellow  stains  indicate  incomplete  washing  after  the  mercury  bichlo- 
rid  bath. 

The  process  of  intensifying  gives  added  density  to  every  part  of  the 
plate  in  proportion  to  its  original  density.  This  increases  the  contrast 
between  the  parts  but  slightly  affected  by  the  .r-ray  and  the  other  parts 
which  are  decidedly  affected. 

Intensification  is  a  perfect!}"  legitimate  expedient,  but  it  has  not  been 
adopted  in  making  any  of  .the  radiographs  in  the  present  volume,  and 
the  author  always  tries  to  avoid  the  necessity  for  it  by  employing  an 
exposure  which  will  give  a  good  picture  with  normal  or  somewhat 
forced  development. 

It  is  useful  for  underexposed  negatives  and  also  for  certain  over- 
exposed negatives.  In  the  latter  case  the  plate  lias  sometimes  been 
kept  from  becoming  too  dense  by  the  use  of  restrainer  or  very  careful 
development;  but  still  a  print  from  it  presents  scarcely  any  contrast. 
This  defect  may  sometimes  be  remedied  by  intensification  of  the 
finished  negative. 

The  results  are  very  much  better  if  the  exposure  can  be  so  regulated 
that  normal  development  suffices. 

The  Choice  of  Developers.  —  As  a  general  thing  there  is  very  much 
to  be  gained  by  using  the  developing  formula  recommended  by  the 
manufacturer  of  the  plate  or  film.  An  example  of  this  fact  was  lately 
brought  to  the  author's  attention.  A  friend  had  been  using  a  certain 
film  on  his,  recommendation  and  with  excellent  results.  After  about 
a  year  the  quality  of  the  pictures  suddenly  underwent  a  radical  change. 
The  same  subjects  that  formerly  required  an  exposure  of  ten  seconds 
now  required  forty  seconds,  and  the  pictures  were  lacking  in  brilliancy 


800  MEDICAL    KLKCTKICITY    AND    KONTCEN    RAYS 

and  contrast.  After  considerable  correspondence  with  the  company, 
it  transpired  that  they  were  using  a  new  emulsion  on  these  films  and 
that  they  recommended  a  different  developer  from  the  one  that  he  had 
l>een  using.  The  moment  that  the  right  developer  was  used  the  results 
became  as  good  as  wiili  tin1  old  films. 

Development  in  Tropical  Countries.— The  difficulty  is  almost  en- 
tirely a  matter  of  temperature,  the  atmospheric  humidity  not  having 
much  (if  a  disturbing  effect  except  in  making  the  plates  and  films  dry 
very  slowly.  The  usual  developing  solutions  must  be  used  at  a  tem- 
perature of  about  t).~)°  F.  and  can  only  be  used  if  ice  is  available. 
Where  it  i-  impracticable  to  keep  the  solution  at  about  this  temperature 
means  must  be  adopted  to  harden  the  sensiti/ed  coating  of  the  film 
or  plate.  This  is  done  by  immersion  in  a  solution  of  formalin.  The 
developer  must  also  be  somewhat  different  from  the  normal  one. 


HO  parts 

1    part 

for  about  three  minutes,  rocking  the  tray  occasionally,  then  rinse  well 
and  place  in  the  developer.  If  the  image  flashes  up  in  less  than  forty 
seconds  add  more  of  the  potassium  brotuid.  Development  should  be 
complete  in  four  minutes  if  the  exposun-  has  been  normal. 

The  Explanation  of  Some  Defects  in  Developed  Plates. — Some- 
time- the  i'il m  /x  ir/isfml  o//"the  plate,  leaving  perfectly  clear  glass  at  the 
edires.  -hading  gradually  into  the  pictured  part  of  the  plate.  This  is 
apt  to  occur  with  a  developer  that  is  a  little  too  warm  if  the  plate  has 
to  be  left  in  it  for  a  long  time  and  has  to  In-  handled  much.  Carried  to 
an  extreme,  the  whole  picture  would  be  washed  oft  the  plate. 

Tin-  sensitized  coating  of  the  plate  may  be  full  of  r/v/rA-.s-  running  in 

every  direction  and  dividing  the  surface  into  numerous  sections.      This 

lion  i-  usually  due  io  t  he  use  of  t  oo  warm  solut  ions  for  developing, 

:.   ..•._.    or    \va-himr    t  he    plat  e. 

There   may   t>e   a   general    n/n/>!i/i</   which   produces   quite   a   regular 

pa''ern  in  ih''  picture,  somewhat  like  the  design  known  as  marbling  in 

decorative    art.      This    occurs    when    a    strong    developer    like    pyro    is 

1    .    to    ad    Vvithout    stirring.      It    can    be   avoided    bv    keeping    the 

LJ  solution  in  mot  ion  by  rocking  i  he  i  ray,  or  by  the  use  of  t  he 

in  ibator.   or,   it'    a    large    heaw   trav   is  u-ed    which   cannot    be    eonve- 

nii'iit  ly  kept  in  mot  ion.  the  solution  can  be  kept  in  circulation  by  moving 

''.•    finner-t  ips  about    m  it.      A   verv  weak  developer,  such  as  is  used  in 

•  ,'elopment .  has  not  much  tendency  to  produce  this  defect ,  because 

in    the    lonii    time   that    the   [date   is   iniliiersed    in    the   solution    it    has  ail 

to  permeate  the  film  uniformly.       Kven  then  it   is  safer  to 

:       •  .   ion-    against    it.      The    plate.-    -houM    be   taken    out    of  tho 

tank    itti  •    a   -horl    time  and  put  back  the  other  sid<'  up:  and  the  entire 

•  n  fri  mi  t  ime  to  time. 


THE    X-RAY  891 

Pin-holes  result  from  the  adherence  of  air-bells  to  the  film  surface. 
These  prevent  the  action  of  the  developer  and  leave  perfectly  trans- 
parent spots  upon  the  plate.  The  means  of  prevention  is  to  wipe  off 
the  surface  of  the  plate  lightly  while  it  is  in  the  developer.  Moving  the 
plate  up  and  down  a  few  times  accomplishes  the  same  result  in  tank- 
development. 

Brown  xtuinx  upon  the  plate  are  of  several  different  kinds.  A  mot- 
tled or  streaked  metallic  sheen  over  the  whole  or  a  part  of  the  plate 
impairs  the  value  of  the  plate  to  some  extent.  It  is  a  deposit  from  the 
developing  solution  and  may  be  removed  in  great  part  by  wiping  the 
plate,  before  drying,  with  a  tuft  of  wet  absorbent  cotton. 

Another  kind  of  brown  stain  comes  in  large  spots  some  time  after 
the  plate  has  been  dried  and  put  away  for  storage;  it  is  due  to  imperfect 
removal  of  the  hypo.  Prolonged  washing  in  running  water  prevents 
this  occurrence  which  permanently  damages  the  plate. 

Sometimes  a  plate  will  he  found  to  be  covered  with  a  smidy  xulixloncc, 
which  would  interfere  with  the  clearness  of  the  picture  if  allowed  to 
dry  on  the  film  surface.  This  is  due  to  the  use  of  a  hvpo  solution  which 
has  not  been  filtered.  It  may  be  prevented  by  filtering  the  hypo 
solution,  or  it  may  be  removed  after  it  has  occurred  by. wiping  the  plate, 
before  drying,  with  a  tuft  of  wet  cotton. 

Frilling  of  the  film,  or  separation  of  the  sensitized  film  from  the  glass 
near  the  edges,  is  due  to  the  use  of  too  warm  solutions.  There  is  no 
remedy  for  it  afterward.  The  only  thing  is  to  guard  against  it  by  using 
solutions  at  a  proper  temperature,  or,  if  this  is  impracticable,  to  adopt 
the  measures  described  under  ''Tropical  Development." 

The  whole  or  a  large  part  of  the  sensitized  film  sometimes  separates 
in  a  continuous  sheet  from  the  glass  plate  or  from  the  celluloid  film. 
If  this  occurs  with  perfectly  normal  development  it  is  suggestive  of  an 
imperfection  in  the  plate  or  film  and  a  new  supply  should  be  obtained. 
This  has  happened  once  or  twice  in  the  author's  experience.  Once  was 
quite  recently  with  a  very  thin  celluloid  film  which  was  not  of  the  non- 
curling  variety. 

The  presence  of  grcut  blotrhcs  upon  the  plate  may  bo  duo  to  two  dif- 
ferent causes:  j'u'xt,  immersion  in  a  strong  developer  without  previously 
wetting  the  plate  thoroughly  with  plain  water  and  without  taking 
pains  that  every  portion  of  the  plate  is  immediately  completely  wet 
with  the.  developer;  and  second,  some  defect  in  the  plate  which  makes 
parts  of  it  less  sensitive  than  other  parts. 

A  general  mottled  appearance,  coining  as  a  sort  of  fog,  if  the  plate  is 
underexposed  and  requires  prolonged  development,  is  more  apt  to  occur 
if  the  plate  is  old;  and  many  an  abdominal  picture  will  prove  a  failure  if 
plates  several  months  old  are  used.  A  plate  becomes  more  sensitive 
and  hence  more  rapid  with  age.  but  the  change  is  not  an  absolutely 
uniform  one.  There  is  no  means  of  improving  such  a  plate.  The  only 
prevention  is  to  use  fresh  plates.  This  is  one  great  drawback  to  the 
use  of  special  .r-ray  plates  except  in  the  largest  cities.  There  may  not 
be  sufficient  demand  for  them  to  enable  the  dealer  to  keep  an  absolutely 
fresh  stock.  The  best  plates  for  daylight  photography  give  results 
which  are  practically  identical  with  those  obtained  with  .r-ray  plates, 
and  every  dealer  carries  a  fresh  supply  of  them.  The  same  .r-ray  plates 
which  present  this  kind  of  foir  from  being  too  old  may  give  perfectly 


S'.»2 

good  pictures  nf  i  he  hand  nr  any  pail  where  the  .r-rav  effect  is  so  strong 

'    only  normal   development    is   required,  and  tin-  differences  in   the 

decree-  iii   sensitiveness  ot   certain  spotsem   the  plate  are  not  discoverable. 

\   1  1    •    17-inch  plate  means  quite  :i  loss  if  it  has  to  he  thrown  tnvay, 

and  Mill  this  >i/.c  i-  only  used  i'oi1  ihc  largest   portion-^  of  !  he  bodv  and 

•s  prole  i]  el'ipi    cut.      li  is  unwise,  t hcri  fore,  to  use  one  for 

this  purpose1  if  it    I-  more  than   t  \vo  months  old.      The  plate,  however, 

may  he  nil  up  Hit 1 1  smaller  sixes  and  used  for  ra< ho i:Ta | »hs  of  the  exl  remi- 

ties.      [•   would  no!   he  wise  1o  try  to  make  a  frontal  .-inns  picture  on  a 

piece  nit   from  such  a  plate  because  the  same  conditions  prevail  here  as 

i:i   '  i1  abdomen. 

'/i/iir  /Y>//r.s-.— This  is  done  by  drawing  a  line  on  the 

irlass  not  the  film — airface  with  a  glass  cutter  and  i  hen  bending  it 
away  from  the  scratched  surface.  This  can  be  readily  done  before  the 
plate  has  been  developetl;  but  i  he  latter  process  makes  the  film  so  dense 
and  tough  that  one  is  very  likely  to  break  the  plan  into  several  pieces, 
instead  of  breaking  it  along  a  straight  line.  Still  it  sometimes  happens 
that  'lure  is  just  a  small  part  of  a  larue  developed  plate  which  one 

\vi.-heS   to   cut    o:;t  . 

'I'o     tt  (i  </(    '  In/it  it  jilt/ii  one  should  scratch  all  t  he  coating  off  a  broad 
line  of  the  film  surface  and  then  draw  a  line  alon^  this  bared  surface 
'.  li  tin    dass  cutter.     The  plate  is  broken  by  bending  it  away  from  the 
iii  iii'  i  serai  ch  on  the  film  surface. 

Too   strong  developer  causes   the   image  to   flash   right    up.   soon 
;eiis  the  whole  plate,  and  obliterates  the  liner  shades. 
Too  long  development  obliterates  the  details.     A  print  from  such 
a  [date  is  pool'.      The  plate  turns  gray  or  bluish  trray. 

Scratch-marks  on  the  finished  plate  may  ruin  an  excellent  picture. 

They  come  from  even  very  slight   rubbing  of  the  sensitixed  surface  at 

utiv    time    before    development.      !•  nciion    which    may    not   be   nearly 

sufficient   to  scratch   through   the  film  and  expose  the  ulass  plate  will, 

;;•  •••.  en  iii  -les~.  so  affect  i  he  sen  si  t  i  ven  ess  of  t  he  f  i  1 1 1 1  as  to  make  an  indelible 

on     lie    ini>hed  plate  and  any  prim-  made  from  it.      There  is  only 

to  prevent  this  accident  and  thai  is  not  to  touch  the  sensitixed 

-  irface  rt'itli  any  hai'd  substance  until  after  it    has  been  developed  and 

["he  finished  plate  is  quite  durable  and  will  siand  any  ordinary 

',vj..  but  if  it  is  to  be  used  a  number  of  t  hues  for  purposes  of  demon- 

s'ra'ion  i'  had  better  be  protected  by  varnish. 

Varnishing  the  Plate. — A  varnish  is  made  for  this  purpose  which 

dries  dear  and  hard.      The  plate  is  he-Id  honxont a lly  in  one-  hand  while.' 

ounce  or  more  of  varnish  is  poured  over  it.     Tins  is  allowed  to 

over  d iff'  t1' -Jit  parts  of  the  plate  unt  il  t  he  <'iit  ire  film  surface  has  been 

.•  '   and  th'-n  it  is  drained  back  into  the  bottle.      The'  plate  is  stood  up 

•    ;  to  dry  in  a  place  \vhicli  is  free  from  dust. 

Perspiration-marks    on    the    Plate.-  The    ordinary    envelope    in 

tes  arc.1  useel  is   perfectly  permeable  to  moisture',  and  the 

triko  through  from  any  part  of  ihe  bodv  which  lies 

ion   i;.     Th(:  chemic   properties   of   the    perspiration   cause   it 

..    .  •  •     '    effect    upon   the   !ili!i.  ;.nd   this   is  sho\\  n   as  a 

spots  on  the  fini.-hed  plate,  or  \\hite  spots  on  the 

es   it    an    invariable  ciisiom   to   lay  a  piece  of 

•  :   or  cardboard  under  the  part  thai    rests  upon 

the  > 


TIII-:  .T-RAY 


The  envelopes  which  contain  the  plates  may  produce  an  injurious 
effect  upon  the  sensitized  surface.  Ordinary  paper  contains  so  much 
sulphur  that  it  is  entirely  unsuited  for  this  purpose  and  even  tin- 
specially  prepared  envelopes  are  not  entirely  safe.  To  be  absolutely 
secure  against  trouble  from  this  source  the  plates  should  be  kept  in 
the  original  boxes  until  just  before  use,  and  then  should  be  put  in  the 
opaque  envelopes  in  the  dark  room.  I'sually,  however,  the  envelopes 
are  safe  enough  for  .several  weeks,  except  for  some  case  which  result.-  in 
underexposure  and  prolonged  development;  then  the  slight  harmful 
effect  upon  the  plate  may  be  brought  out  and  may  entirely  overshadow 
the  picture.  The  -paste  which  is  used  to  fasten  the  seams  of  the  envelope 
has  an  especially  deleterious  effect  upon  the  photographic  plate,  and 
the  plate  should  always  be  put  in  the  envelopes  so  that  the  smooth  side 
of  both  envelopes  is  at  the  film  side  of  the  plate. 

The  author  almost  always  exposes  two  plates  at  the  sam"  time, 
so  as  to  have  one  to  send  to  the  physician  and  one  to  retain  as  a  record. 
Trouble  due  to  the  effect  of  the  envelopes  upon  the  film  can  be  avoided 
by  keeping  two  plates  face  to  face  in  the  same  envelope,  being  careful 
nut  to  produce  the  scratch-marks  referred  to  above. 

Sulphur  and  moisture  affect  photographic  films  very  badly  and 
plates  must  be  carefully  protected  from  both  of  these.  The  amount  of 
sulphur  present  in  the  air  of  ordinary  dwellings,  especially  if  lighted  by 
gas,  is  shown  by  the  quickness  with  which  silver  tarnishes.  Tin-  sensi- 
tixed  film  is  really  an  exquisitely  susceptible  silver  surface.  The  same 
factors  occasionally  damage  the  plates  and  films  which  are  sent  across 
the  At lant ic  Ocean. 

Fogging  from  ,r-Ray  in  the  Place  in  Which  the  Plates  are  Stored. 
— The  plates  should  be  stored  in  another  room  and  separated  by  a 
bi'ick  wall  from  the  .r-ray  tube.  Kven  then  they  should  not  be  kept 
on  an  ordinary  shelf,  but  should  be  in  a  lead-lined  box.  and  the  cover 
of  this  should  never  bo  left  off  when  1  he  .r-ray  is  t  urned  on  in  an  adjoining 
room.  Ordinary  light  diffuses  into  an  adjoining  room  through  an  open 
door  even  if  a  screen  is  placed  to  cut  off  the  direct  rays  from  the  lamp; 
and  in  just  the  same  way  secondary  rays  arise  from  every  object  in  the 
.r-rav  room  and  any  adjoining  room  not  separated  by  an  impenetrable 
pail  it  ion  such  as  a  bi'ick  wall. 

Tin'  danger  of  ruining  plates  Or  films,  which  may  represent  several 
dollar-'  worth  of  material  or  several  hours  oi  labor,  by  a  few  seconds' 
exposure  to  the  .r-ray  is  something  that  -hould  be  constantly  borne  in 
mind.  It  is  an  excellent  rule  ne\er  to  bring  an  undeveloped  plate  or 
film  into  the  .r-ray  room  at  any  time  except  when  that  special  plate  i- 
to  be  exposed  for  a  radiograph.  Another  u-ood  rule  is  to  have  the 
cover  of  !  he  lead-lined  box  for  plate.-  and  films  made  in  such  a  way  t  hat 
the  cover  cannot  be  taken  off  entirely,  and  thai  it  will  shut  of  it-  own 
weight  except  when  held  open  by  the  hand.  In  this  way  the  box  can 
never  be  left  open  accidentally.  The  author  uses  a  wash-boiler,  measur- 
ing liXl">>  -1  inches,  for  storinsj;  unu>ed  plates  and  film-.  He  lined 
t  hi-  himself  with  sheet -lead  held  in  place  by  strips  of  adhesive  plaster. 

Storage  and  Filing  of  Developed  Plates  and  Films.  The  >/m/// 
film*  on  which  tooth  radiographs  are  made  are  marked  with  white  ink 
after  development,  and  all  1  he  sin  a  II  film-  of  each  pat  ieni  are  put  in  an 
envelope  marked  with  the  name  <>i  the  patient  and  the  examination 
r.  Thus,  the  envelope  mav  be  marked  "Brown,  lb:;:',;  1.  i'.  :•!." 


MKIHCAL    ELECTRICITY    AND    RONTGEN    RAYS 

Those  envelopes  are  all  arranged  in  numerical  order  in  a  card  index 
drawer,  but  there  is  also  a  card  index  of  all  patients'  names  from  which 
the  examination  numlxT  and  the  size  of  the  plate  or  film  can  he  learned 
in  a  moment. 

Each  physician  referring  eases  has  a  card  in  my  card  index  giving 
the  names  of  his  different  patients  and  their  examination  numbers. 

Lanjcr  Jilni*  up  to  5X7  inches  are  stored  in  numerical  order  in  a 
negative  film  file.  The  latter  looks  like  a  photograph  album,  but  each 
leaf  is  made  up  of  thin  transparent  paper  forming  a  jxicket  into  which 
a  film  may  be  slipped.  A  hundred  films  filed  in  this  way  take  up  no 
more  room  than  a  l>ook  measuring  5*  X8*,  inches  and  1  inch  thick. 

Films  larger  than  5X7  are  kept  in  separate  envelopes  and  filed  in 
pigeon-holes. 

/•'//< 'N  for  riah*  Cp  To  and  Induilintj  8X10  I nclicx. — An  excellent  type 
of  these  is  sold  in  America  under  the  name  of  the-  Star  negative  file 


Y\it.  ")('>(). — Star  negative  filo. 

'Fig.  .")('»()).  It  is  made  for  5X7-,  or  (iJXN?.-,  or  SX  11-inch  plates  and 
consists  of  a  box  (•  inches  thick,  and  long  and  high  enough  for  the  proper 
sixe  plate  to  tit  in  it  in  a  vertical  position  between  pasteboard  partitions. 
The  plaies  require  no  envelopes  and  a  notch  at  the  top  of  each  partition 
enables  one  to  see  the  number  marked  on  the  plate  in  white  ink.  Jvich 
Hie  holds  50  plates  and  when  filled  with  the  largest  si/ed  plates  (NX  10 
indies)  it  weighs  only  a  little  over  'JO  pounds.  The  smaller  ones 
weicji  proportionately  less.  There  is  no  difficulty,  therefore,  in  lifting 
them  off  a  close!  shelf  and  carrying  them  to  the  light  in  order  to  find 
any  particular  plate,  though  it  would  be  more  convenient  if  one  had  a 
sale  place  to  .-tore  them  where  there  was  a  good  light. 

The  same  vertical  Hies  may  be  used  for  celluloid  films  and  will  hold 
three  or  loiir  of  these  in  each  section. 

Sloriitfr  ,if  l-'inlxlinl  I'lntc*  Lnri/cr  ffmn  S  -JO  Inclicx.-  The  UX  17- 
inch  plates,  weii;h  '.}  pounds  apiece  and  mav  be  stored  in  the  heavy 
cardboard  boxes  in  winch  six  of  them  are  originallv  sold.  The  number 
"I  each  of  the  six  plates  should  be  \\ritlen  on  the  outside  of  the  box, 
,''!.'!  the  boxes  -honld  be  stored  vertically  between  wooden  partitions 
about  i1.  inches  apart.  The  wav  which  is  adopted  bv  the  author  is  to 
keep  every  plate  larger  than  SX10  inches  in  a  separate  envelope,  and 
to  file  the  plates  of  each  si/e  together  between  vertical  board  partitions 
about  f  i  inches  a  pa  !'t  . 


THE    X-RAY  895 

Largo  films  had  bettor  ho  kopt  in  separate  envelopes  made  for  the 
purpose  with  a  thin  sheet  of  stiff  cardboard  and  may  then  be  placed 
in  a  port-folio,  or  filed  between  vertical  partitions,  or  kept  in  a  drawer. 
Their  lightness  and  the  fact  that  they  cannot  be  broken  makes  films 
very  much  more  convenient  to  preserve  than  glass  plates. 

FLUOROSCOPY  AND  RADIOGRAPHY  OF  SPECIAL  PARTS  OF  THE  BODY 

The  fluoroscope  has  a  very  definite  field  of  usefulness;  first,  in 
determining  the  quality  of  the  radiance,  and  second,  in  the  examination 
of  cases  in  which  a  glance  tells  the  whole  story.  Time  passes  so  rapidly 
when  a  patient  is  being  examined  and  considered  that  the  use  of  the 
fluoroscope  may  lead  to  a  dangerous  length  of  exposure.  One  case  in 
point  was  communicated  to  me  privately  by  an  eminent  physician  in 
this  city.  A  friend  of  his  had  some  affection  of  the  knee-joint  for  which 
a  fluoroscopic  examination  was  made  and  a  consultation  held,  it  being 
estimated  afterward  that  the  knee  had  been  exposed  to  the  x-ray  for 
forty-five  minutes.  The  result  was  a  dermatitis  followed  by  a  pain- 
ful and  intractable  ulcer  with  such  an  effect  upon  the  system  at  large 
that  to  save  the  man's  life  and  reason  an  amputation  was  performed 
above  the  knee.  Another  case  was  reported  by  an  excellent  radiologist, 
Guilleminot,1  who  had  been  in  the  habit  of  removing  foreign  bodies 
from  the  hand  under  fluoroscopic  observation.  For  instance,  he  would 
roughly  locate  a  needle  by  means  of  the  fluoroscope,  take  the  patient 
into  daylight  and  make  an  incision,  then  in  the  dark  again  guide  the 
forceps,  by  means  of  the  fluoroscopic  image,  until  the  needle  was  felt 
and  seized.  In  the  case  reported  the  noodle  could  not  be  found,  although 
two  separate  attempts  were  made  four  days  apart.  During  these  two 
seances  the  patient's  hand  and  both  the  doctor's  hands  were  actually 
exposed  to  the  .r-ray  for  about  thirty-five  minutes.  The  distance  from 
the  tube  was  3  or  4  inches,  the  vacuum  was  low.  Although  he  does  not 
give  the  strength  of  current  used,  it  must  have  been  considerable  to 
enable  the  needle  to  be  seen.  The  patient's  hand  and  both  the  surgeon's 
hands  developed  a  very  severe  dermatitis  with  alteration  which  took 
six  months  to  heal  completely  and  the  skin  was  not  absolutely  sound 
at  the  end  of  a  year.  It  does  not  follow  that  the  fluoroscope  should 
never  lie  used,  but  it  is  certainly  very  dangerous  in  a  case  where  the 
image  has  to  be  studied  for  an  uncertain  length  of  time. 

(.\nlc. — In  the  author's  radiographic  teclmic  the  spark  length  is  measured  be- 
tween moderately  sharp  points.  It"  measured  between  polished  bulls  his  4-inch  spark 
should  be  2.1  inches,  and  his  o-ineh  spark  should  be  4  inches.) 

1  Archives  D'Electricite  Medicale,  Bordeaux,  France,  Dec.  10,  1904. 


S'.lli 


THE   AUTHOR'S   TABLES   OF   RADIOGRAPHIC   EXPOSURES 

Er.foeurefi  for  r.ct  1  lcgr-\phy  of  the  Teeth. 
Th»  Slow  Dental  Films  (Formerly  called  Eaatiran  Positive  Cinematograph   Filitg.) 


A.   For  the  expert  Roentger.ologlPt . 


13  Inches  distance,  4  Inch  spark  30  milll- 
airperee,  1/5  n-.llllir.eter  aluirlnum  filter. 


Jnl  1  Jrer. 

Vyrer  Molara 

6    •-•   •  . 

Lower  Uolare 

Bicuspids 

5  sec. 

;.cwer  Ir.cir-cra 

Vrrer  Incisors 
4  so-. 

Adults 
ice  t  c 

15C  Us. 

r  Bec, 

£   sec. 

5  eec  . 

4   sec. 

4  1/2  sec 

A  ;  •  J  1  1  J 

10   sec. 

6   sec  . 

6  r-ec. 

5   S6C  . 

5  sec. 

E.   For  the 

Dentist. 

Inches  distance,  6  Inch  spark,  10  rilllaiperes . 


Children 

Upper  l!olare 
6  eec. 

Lower  Molars 
6  sec  • 

Eicusp  ids 
5  sec. 

Lcwer  Incieore 
3  eec. 

Upper  InciBCrs 
5  eec. 

Adults 
ICC  to  15C 
Irs. 

8  sec. 

7  see  . 

6  sec. 

ft  aec. 

6  sec. 

Adults  over 
1£C  ibe. 

10  sec. 

8  aec. 

7  pec. 

5  aec  . 

7  eec. 

Bxposura  Table  for  Radiography  of  the  Head  (except  the  teeth)  and  of  the  Seek. 
(Exposure  in  seconds,  using  Seed  X  Ray  Plates  or  Eastman  Duplltized  X  Ray  FlEo 
Sei  Female-  Kale. 


•eight,    Ice. 

20 

40 

90 

ieo 

160 

200 

: 

50 

110 

i  140 

180 

220 

t&ai,    ar.taro- 

pcoterlcr,    5 

ir.c.'i      epir*. 

2^    -A  ,    Jr.tonsl- 

4 

4    I/? 

5 

6 

6    1/2 

e 

4 

4    I/? 

6 

6    1/f 

7 

3    l/£ 

-jir.j     screen, 

1  .-  ;;.es   ar.ti- 

Ciitr.cde    to   plate 

-.   ,-l"i  ,       1-1  t.  •-Til  , 

-IT.  9    t-c:.r.ic. 

8 

S 

p.  i/n 

3 

4 

4    1/f 

r 

r   l/r 

3 

4 

4    1/2 

5 

Jaw  ,     litor  il 

u;     r,     -i-     rr.al 

;  .at  -3  ,L    Ir.ch 

:      \/7 

3 

4 

4     1/3 

£ 

: 

3 

4 

4    1/J 

5 

6 

p  ;  ^  .-  K  .     I  .    r  -t  , 

:.••     , 

..  . 

'••         /.  ,       i"i"  •   :    i  . 

.     '  ,     ' 

.    i  ,        .       •      •  • 

•', 

;, 

10 

i: 

li 

1 

. 

12 

14 

15 

:.        .: 

v  -'•••' 

897 


Exposure  Table  for  Radiography  of  the  tipper  Extremity. 

Exposure  In  seconds,  using  Seed  X  Ray  Plate  or  Eastman  Duplltlzed  X  Ray  Film, 
23  Inches.   Ho  Intensifying  Screen  except  when  BO  stated. 


Female. 


Vale. 


•eight,  Iks. 

20 

40 

eo 

120 

160 

200 

20 

50 

110 

140 

180 

2PO 

Shoulder.   Plate 

behind.  Tube 

near  median  line 

4 

5 

8 

10 

12 

15 

4 

5  % 

9 

IP 

14 

15 

in  front.  4  Inch 

spark.  30  ma. 

Shoulder.   Plate 

in  front.  Tube 

behind,  10  inches 

4 

5 

8 

10 

IP 

15 

4 

5  /^ 

9 

12 

14 

15 

from  median  line. 

Same  technic. 

Shoulder.   Plate 

in  front  ,  Tube 

4 

5 

8 

10 

12 

15 

4 

5;/7 

9 

12 

14 

15 

near  median  line 

behind.   5  inch 

iimpl 

j  to 

ehow 

upper 

part 

Of  1 

imeru 

3  in 

a  pla 

ie  at 

rlgh 

b 

spark,  30  ma,  In- 

anftl 

38  tO 

the 

other 

a  to 

revef 

L  dis 

;lace 

•nent 

n  ca 

30  Of 

tensifying  screen. 

frac 

ture 

of  th 

e  nec[k  of 

the  1- 

iroeru 

3. 

Arm,  Forearm  and 

Elbow.   4  inch 

2  '/! 

3 

4 

5 

6 

8 

2  /^ 

3 

4 

6 

7 

8 

spark,   30  ma. 

Wrist,  antero-pce- 

terior  prone,  4 

2 

2  Ib, 

3  'A 

4 

5 

6 

2 

2  £ 

T 

4 

6 

8 

inch  spark,  30  ma. 

Wrist,  lateral,  4 

2  fa 

3 

5 

fi  % 

7  '/„ 

P  '/* 

3 

4 

5 

7  #, 

10 

inch  spark  30  ma. 

Hand,  prone  Fingers 
prone  or  one  fin- 

1 '/-, 

2 

•*£ 

Z 

4 

4  'A 

1  'h. 

2 

»* 

3 

4  ^7 

6 

ger  lateral,  4  Incl 

spark,  30  ma. 

Exposure  lablo  for  Ribs,  Lungs,  Heart  Aorta  and  Oesophagus; 

Also  for  Dorsal  Vertetrae.  Exposure  In  seconds  using  Seed  X  Ray  Plata 

or  Eastman  Duplltlzed  X  Ray  Film. 

Sex  Female.  Male. 


Weight,  Ibs. 

20 

40 

90 

180 

160 

200 

20 

50 

110 

140 

180 

220  

Ribs,  lungs. 

heart,  oesophag- 

us and  aorta, 

Antero-posterior; 

i-late  front  or 

4 

6 

8 

10 

1? 

15 

4 

5t 

10 

13 

15 

13 

back,  23  inches, 

4  inch  spark,  30 

na  .  No  screen. 

Ribs,  lungs,  heart, 

oeaophagus  and 

aorta;  lateral. 

.  if 

Same  teehnio  but 

4 

5 

8 

10 

12 

15 

4 

5-4 

10 

13 

15 

19 

with  intensifying 

screen. 

Dorsal  vertebrae, 

plate  behind,  25 
inches  ,  5  inch 

4 

5 

8 

10 

12 

15 

4 

5  £ 

10 

13 

16 

18 

spark,  30  ma. 

Dorsal  vertebrae 

Lateral   Same 

technic  but  with 

4 

5 

8 

10 

12 

15 

4 

5  % 

9 

12 

14 

15 

intensifying 

screen. 

898 


MEDICAL    ELECTRICITY    AND    KONTCEN    HAYS 


Sex.   Mile 


Exposure  Table  for  Radiography  of  the  Abdoiren  prone  upon  the  Piste. 
(Call-bladder,  Pancreas,  Empty  Stomach  and  Intestine. ) 

And  for  Radiography  Supine  upon  the  plate  with  Compression 
(itidneye,  tretere,  Bladder,  Lucbar  Vertebrae  and  Felyis.) 
Also  for  the  hip-Joint. 


Exposure  A,  Frcne 

Waist 

26 

27 

S8 

29 

upcr.  plale  cr  Supine 
*itr.  ccnf-rosslcr.. 

Hips 

32     54 

3^      55 

34    36 

35      38 

Vertebrae  requires 

Pcunde 

113 
110    120 

11!     127 

127    156 
143    183 

131    155 
150    180 

Exposure  A 

4    e 

5       7 

6     8 

7    10 

Child  28  Iba,  19  wala 
2C  hip,  2  1/2  sec. 

Exposure  E 

5      7 

e     e 

8    12 

Waist 

2C 

33 

33 

33 

Exposure  E,  Is  for 
tip-  Joint  prone  or 

Kips 

J5     36 

35     36 

35    38 

38    40 

F  curds 

122    150 
146    180 

155 
146    16C 

146   170 

All  ar«  £3  inches, 
Seed  X  Say  I  late  or 

Exposure  A 

1C     15 

1C     IP 

11    13 

11    14 

Eaetiar  Luplitlzed 
X  r.aj  Flic,  4.  inch 

Exposure  B 

12     14 

12     14 

13    15 

13    16 

eparx,  by  preference, 
with  Intensifying 

Kalst 

54 

35 

36 

37 

ldit>  .   Cr  £  inch 
spark  without  screen, 

Kl£_B  __ 

3e     4C 

26     4C 

36    40 

36   40 

20  clillairperes.  hip 
and  waist  circucfer- 

Founds 

14C    ISC 

14S 

150     1=C 

135 
165   180 

156   180 

ence  In  inches. 
Exposure  in  seconds. 

Expceurs  A 

12-    14 

12    ie 

IE    18 

13    19 

Exposure  E 

14   ie 

14      19 

14    21 

15   22 

Saiat 

38 

39 

40 

41 

•:ips 

37     4C 

37     41 

40 

40 

Founds 

155    1P3 

150     FCO 

172   215 

•190 

Exposure  A 

14     ?0 

15      21 

16    21 

17    22 

Exposure  E 

16     23 

1R      ?5 

19    25 

20    26 

Walat 

4F 

43 

44 

45 

Hips 

40 

40 

41 

42 

Pcurds 

P06 

232 

FT;  caure  A 

18    P3 

IS    24 

18    25 

20   30 

Exposure  B 

21    26 

21    2B 

21    29 

23   35  _  . 

THE  X-KAY 


899 


Exposure  Table  for  Radiography  of  the  Abdomen  Prone. upon  the  Plate. 
(Gall-Bladder,  Pancreas,  Empty  Stoirach  and  Intestines.  ) 

Ana  for  Radiography  Supine  upon  the  plate  with  Compression 
(Kidneys,  Ureters,  Bladder  Lumbar  Vertebrae  and  Pelvis- j 
Also  for  the  Hip-Joint 


Female. 


Exposure  A,  prone 
upon  plate  or 
supine  with  com- 
pression, (lateral 
of  Lumbar  Vertebrae 

Waist 

22. 

23 

24 

25 

Kips 

28     59 

28    36 

28     37 

54      39 

Pounds 

85    100 

95 
117    IIS 

68     103 
95     142 

86 
119     145 

ex;  osure.  ) 

Child  28  Ibs,  IS 
waist,  20  hip, 
2  1/2  'seconds,  with 
this  technic. 

Exposure  B,  IB  for 
hip-Joint  prone  or 
BUI  ine  . 

All  are  23  Inches, 
Seed  X  Ray  Plate  cr 
Eastman  Duplitlzed 
X  Kay  Film,  4  inch 
ej.ark,  by  preferenc 
with  intensifying 
screen  of  2  1/2 
rapidity.   Or  5 
Inch  sparK  without 
screen,  30  millian:- 
peree.   Hip  and 
waist  circumference 
In  Inches. 
Exposure  in  seconds. 

Exposure  A 

4      € 

5       B 

6      9 

Exposure  B 

6      7 

6      9 

6       9 

7     10  ^ 

Waist 

£6 

27 

28 

29 

Hips 

35     39 

36     42 

35    42 

36     40 

Founds 

110 

lie   150 

ICO 
118    163 

Ifl   137 

i:*c  iec 

IOC    138 
138    180 

Exposure  A 

6      9 

8      9 

8    10 

8     10 

Exposure  B 

7     10 

9     10 

9    12 

9     12 

Waist 

30 

31 

32 

33 

Kips 

36     43 

39     43 

36     44 

36     44  _, 

Pounds 

li!  MI 

307 

Ifl    180 

Exposure  A 

9     10 

9     13 

10    14 

10    14 

Exposure  B 

10     12 

10     14 

12    16 

12    16 

Waist 

34 

35 

36 

37 

Hips 

36     44 

36     44 

39     47 

38     47  ^ 

Pounds 

136    180 

136    180 

150    195 

150    195 

Exposure  A 

10     16 

12     18 

14     £0 

14    22 

Exposure  B 

12     18 

14     21 

16     24 

16    26 

Waist 

38 

39 

Hips 

39    47 

39    47 

Pourrte 

170   200 

170    COO 

Exposure  A 

16    24 

20     24 

Exposure  B 

19  .  28 

24     28 

900 


MKIHCAL    KLKCTKiriTY    AND    RONTGEN    HAYS 


Exposure  Table   for  Radiography   of   the  Stomach  and   Intestines. 


(Exposure  In  seconds,  using  Seed 
and  an  Intensifying  Screen  of  2 
Waist  and  hip  circumference  In 


X  Ray  Platee  or  Eaetraan- Duplitized  X  Ray  Films 
1/2  Rapidity.      6   inch   spark,    50  irilllamperes. 
inches. ) 


Exposure  A  23  inch- 

Waist 

26 

27 

28 

29 

be. 
StGEach  and  Intee- 

hlpa 

32      34 

32      35 

34    3« 

35     38 

Pounds 

115 
110N    IT? 

113     127 

1P7   156 
143   185 

131    155 

150    180 

pTpoeure  fc  18  or  19 

Inches,  Stomach 

Exponure  A 

2     2  £ 

2       5 

2-£   3 

3    33- 

and  Lucdenum. 

Exposure  B 

l^    \ii 

i  r    2 

1      ? 

2    Z± 

Exposure  C  23  inch- 

Exposure C 

i    i-i. 

It      2 

it     2 

li   2 

es.   Appendix  with 
ectcpreeBion. 

Waist 

30 

31 

52 

33 

Hipe 

35     38 

35     3P 

35     38 

36    40 

Founds 

122    155 
146    IPO 

155 
146    IPO 

146    170 

Exposure  A 

3      4 

St    4 

Exposure  B 

2      3 

2^    3 

3      3 

3     3  i 

Exposure  C 

2      2  % 

2      3 

2      3 

2t   3 

Valet 

34 

35 

36 

37 

Hips 

36    40 

•36     40 

36    40 

36     40 

Pounds 

14C    180 

142 

150    IPO 

135 
165     180 

156     180 

Exposure  A 

4     4  £ 

4      C 

4       5 

4^  si- 

Exposure  E 

3     3  i 

3      4 

3      4 

si   4-fc  T 

Exposure  C 

1*   *. 

3      3  -fe 

*     *£ 

s    •*-!•: 

Waist 

JR 

58 

AO 

4S 

Hlpe 

37    40 

37     40 

40 

40 

Pounds 

155    1"3 

15C    POO 

172   215 

190 

Exposure  A 

4&    6  % 

5      5i 

5      6 

5^;  e 

Exposure  B 

Zt    4i 

4      4  V 

4*   Ai 

4^   4-t 

Exposure  C 

3      3 

3      4 

3      4 

4     4 

Walet 

4? 

43 

44 

^S 

Hips 

40 

40 

41 

42 

Founds 

2£6 

232 

Exprflure  A 

6     6  •*£, 

6      7 

6      7 

6     7 

Exposure  E 

4-2   5 

44    5i 

4  1   si; 

4  -fc  5  sr 

Expoaure  C 

4     4 

4      4  i 

4      4  £ 

4S   5 

THE  3>KAY 


901 


Expoaure  Table  for  fiadiography  of  the  Stoaach  and  Intestines 

•Exposure  In  seconds,  using  Seed  X  Ray  Platee  or  Eastman  Duplltized  X  Ray  Pllms 
and  an  Intensifying  Screen  of  8  1/2  Rapidity   5  inch  spark.  30  mil  llamperea. 
Waist  and  Hip  circumference  in  Inches.) 

Female. 


Exposure  A  23  inches 

Waist 

22 

23 

24 

25 

Stomach  and  Intes- 
tines in  general. 

Exposure  E  18  or  19 
inches.   Stomach 
and  Duodenum. 

Exposure  C  23  inches 
Appendix  with  com- 
pression. 

Hips 

28      39 

28     36 

28     37 

34      39 

Found  D 

55    100* 

°5 

ii7   no 

68    103 
95    142 

86 
119   145 

Exposure  A 

1     Z 

1        3 

2.    3 

2    3 

Exposure  B 

I     2 

1        2 

1     2 

2    3 

Exposure  C 

1     I'-S 

1                £ 

1     2 

I'e-  8 

Waist 

26 

27 

28 

29 

Hips 

35      39 

35     42 

36     42 

36     42 

Pounds 

110 
118     150 

100 
118     1S3 

121    137 

130    160 

100    136 
138    180 

Exposure  A 

2      3 

3       4 

3      4 

3      4 

Exposure  B 

2      3 

2       3 

P     3 

2-      3 

Exposure  C 

li   z 

\r,     ? 

1  %    3 

?     2  £ 

Waist 

50 

31 

22. 

33 

Hips 

36     43 

!9     43 

36     44 

36    44 

Founds 

134 
163     141 

107     160 

121    160 

130   180 

7>        S 

4      5 

4     5 

Exposure  E 

3      3 

3       4 

3      4 

3    4 

Exposure  C 

P      2  -Z 

2       3 

2      3 

p-i  si 

Waist 

34 

35 

36 

37 

Kips 

56      44 

36     44 

38     47 

38     47 

Founds 

136     190 

136    IPO 

150    195 

150    195 

Exposure  A 

4       6 

4      6 

4       7 

4      7 

Exposure  B 

3     4 

3      4 

3     4 

3     5 

Exposure  C 

P  •&    3-2 

3      3  '* 

4      4  $ 

4     4  ^r 

Waist 

38 

39 

Hips 

39     47 

39     47 

Founds 

170    POO 

170   rco 

Exposure  A 

6      8 

5    e 

Exposure  3 

4      6 

4      6 

Exposure  C 

4      5 

4      5 

902 


MEDICAL    ELECTRICITY    AND    RONTGEN    HAYS 


With  t\vo  thicknesses  of  tin  to  arrest  secondary  tissue  rays  and 
Kastman  duplitixed  iihn  with  t\vo  intensifying  screens,  )•>()  milliamperes 
and  ~>-inch  spark,  use  the  same  number  of  seconds  as  in  the  exposure 
tables  for  the  abdomen. 


Exposure  Table  for  Radiography  of  the  Lower  Extremity. 

Exposure  In  seconds,  using  Seed  X  Ray  Plate  or  Eastman  Duplltlzed  X  R 
Film.  23  inches,  4  Inch  spark,  30  mllliampereB.  (N.t.  The  hip  Joint 
!•  given  with  the  abdoalnal  exposures.) 


Male. 


Weight,  Ibs. 

ro 

40 

90 

120 

160 

200 

ro 

50 

110 

140 

180 

PPO 

Thigh,  lateral, 

or  antero- 

5      6 

8 

10 

IS 

14 

6 

8 

1C 

12 

ir 

14 

poeter  Icr  . 

Knee,  Leg. 

2  -fe    3 

4 

5 

6 

7 

3 

4 

6 

6 

6 

7 

Ankle,  lateral. 

2  fa 

t 

4 

5 

e 

7 

3 

4 

5 

6 

6 

7 

Ankle,  antero- 
poetericr  . 

3 

4 

5 

6 

7  £    9 

4 

5 

6 

7/k, 

7  'A 

9 

Foot,  prone. 

Toes,  prone  or 

1  h 

2 

3 

3  * 

4 

6 

2 

3 

S  f'i 

4 

4 

5 

one  toe  laterally 

THE  HEAD 

Radiographs  of  the  rrnnnun  as  distinguished  from  the  face  may  be 
made  on  two  different  plans.  One,  which  1  designate  as  a  marginal 
pit-lure,  is  occasionally  useful  when  ihe  portion  to  be  studied  is  a  part  of 
the  skull  or.  at  all  events,  is  near  the  surface.  In  such  a  case  the  head  is 
to  be  placed  upon  the  photographic  plate  in  such  a  position  that  the 
shadow  of  the  portion  of  interest  will  be  at  the  margin  of  the  general 
image  of  the  head.  If,  for  instance,  it  is  about  the  forehead,  the  sagittal 
sut  ure,  or  the  occiput,  the  plate  would  be  placed  al  t  he  side  of  1  lie  head; 
while  tor  a  marginal  picture  of  the  temporal  region  the  patient  would  lie 
with  the  plute  under  the  back  of  his  head. 

In  the  oilier,  which  I  call  the  <l/r<ft  rn<//<>//r/i j>h  of  the  cranium, 
the  portion  of  interest  is  brought  as  close  to  the  plate  as  possible 
and  it-  -hadow  ii-ually  falls  at  about  the  middle  of  tin1  general  image 
ft  the  cranium.  For  a  direct  radiograph  of  a  tumor  of  the  brain  the 
plate  would  commonly  be  at  the  side  of  the  head.  A  marginal  radio- 
graph of  the  cranium  should  show  both  tables  of  the  skull  quite 
clearly. 

I-'rnrftirts  <>i  Ilir  x/.-ull  sometimes  show  very  well  in  the  marginal  view 
\vi *  h  the  fl Horoscope,  us  (1()  also  depressions  or  thinning  of  t  he  skull  from 
the  pn-ss ure  oi  cysts  and  tumors,  hut  with  the  abnormal  portion  of 
th<-  -kull  in  the  centt  r  of  the  image,  the  change  i.-  mrelv  visible  with  the 
fluoroscope.  The  radiograph,  however,  is  extremely  valuable.  The  cur- 
rent u.-«'d  for  an  induction-coil  should  be  IS  to  2">  amperes,  and  the  tube 
should  be  1  '•>  indies  from  t  he  skin  to  t  he  ant  i  cat  h  ode  and  should  have  a 
medium  vacuum,  resistance  about  i>  inches,  and  penetration  Xo.  (i 
Benoi-t .  A  Iran-former,  or  an  unfluctuating  converter,  would  make  the 


THE    X-UAY 


903 


picture  with  70  kilovolts  and  30  to  50  milliamperes.  The  exposure  with 
the  eoil  would  be  from  fifteen  to  sixty  seconds  and  with  the  more  powerful 
apparatus  one-fourth  to  one  second.  Tin;  author's  preference  is  for 
5-inch  spark,  or  (>5  kv.,  30  inches  distance,  30  ma.,  with  intensifying 
screen,  five  seconds  for  150-pound  man  (see  Exposure  Table,  page  890)  or 
any  other  150  milliampere  second  exposure.  In  radiographing  a  case  of 
fracture  of  the  skull  in  profile  the  plate  should  be  placed  upon  a  pillow 
on  the  examining  table  beneath  the  patient's  head,  the  anticathode 
being  30  inches  above  the  plate.  For  a  radiograph  looking  directly 
at  the  injured  portion  the  tube  may  be  at  a  distance  of  30  inches  from 
the  plate,  securing  a  picture  of  the  entire  head  free  from  distortion, 


")(51. — Marginal    radiograph    of    depressed  fra< 

injury. 


if   the  skull,  seven  years  after 


injured  portion  resting  on  the  plate,  resistance  and  exposure 'the  same 
as  for  the  marginal  radiograph. 

Figure  5(>1  is  a  radiograph  of  such  a  case.  The  patient,  a  boy  seven 
years  of  age,  was  beginning  to  lose  his  memory,  possibly  in  consequence 
of  an  injury  received  when  a  baby.  His  father  had  thrown  a  saucer  at 
the  mother,  but  hit  the  baby's  head,  making  a  gutter-shaped  depressed 
fracture  which  still  shows  in  the  radiograph. 

Radiographs  proved  of  value  in  cases  of  "bursting  fracture"  of  the 
skull,  reported  by  Wight,1  the  profile  as  well  as  the  direct  view  being 
successful. 

1  Nc\v  York  Medical  Journal,  April  27,  1907. 


004  MEDICAL    ELECTRICITY    AND    RONTCJEN    RAYS 

Differential  Diagnosis  Between  Hematoma  of  the  Scalp,  Hernia 
Cerebri,  and  Fracture  of  the  Skull. — The  author  has  several  times 
successfully  based  this  distinction  upon  the  fluoroscopic  appearance 
alone.  The  profile  view  of  a  hematoma  shows  the  uniformly  convex 
surface  of  the  skull.  The  raised  margin  of  the  saucer-shaped  depression 
is  seen  to  be  entirely  transparent  and  superficial  to  the  bone  which  takes 
110  pan  in  its  formation.  Turning  the  head  a  little  to  one  side  or  the 
other  does  not  show  any  area  of  translucency  in  the  bone.  A  direct 
view  with  the  fluoroscope,  that  is,  with  the  affected  portion  of  the  head 
nearest  the  lluoroscent  screen,  is  not  as  conclusive  as  a  radiograph  made 
in  this  position.  The  radiograph  showing  a  profile  view  gives  the  same 
results  exactly  as  the  fluoroscopic  examination. 

A  depressed  fracture  of  the  skull  would  be  seen  very  easily  with  the 
fluoroscope  in  profile,  but  here  again  the  radiograph  would  be  necessary 
for  a  direct  view.  Making  almost  a  profile  radiograph,  that  is,  with  the 
head  turned  a  little  toward  the  plate,  we  vill  get  an  image  showing 
irregularity  and  some  translucency,  which,  however,  is  very  much  less 
Than  is  the  case  in  hernia  cerebri,  or  in  diseases  characterized  by  the 
absence  of  bony  tissue  in  a  certain  area. 

The  last  mentioned  disease,  hernia  cerebri,  presents  a  notched  out- 
line when  the  skull  is  examined  in  profile  by  the  x-ray ;  and  in  a  semi- 
profile  view  a  very  distinct  circumscribed  area  of  translucency.  The 
latter  is  also  shown  very  well  in  a  direct  view,  but  requires  a  radiograph. 
The  strength  of  current,  quality  and  intensity  of  the  ray,  and  distance 
from  the  plate  are  the  same  as  in  other  direct  and  marginal  pictures 
of  the  head. 

Tumors  of  the  Brain. — Fluoroscopic  examination  is  not  to  be 
recommended  for  a  tumor  of  the  brain.  There  always  appears  to  be 
a  denser  urea  in  the  part  nearest  the  observer.  Radiography  of  a  brain 
tumor  requires  the  same  technic  as  in  the  profile  radiograph  of  a  frac- 
tured skull.  Two  pictures  should  be  made,  one  with  the  plate  behind 
•tnd  the  tube  directly  in  front  at  a  distance  of  30  inches  from  the  plate, 
and  the  other  from  the  same  distance  with  the  plate  at  the  side  of  the 
head  on  which  the  tumor  is  supposed  to  be  located.  While  many 
radiographs  have  been  made  which  showed  the  presence  of  tumors  of 
the  brain,  subsequently  verified  by  operation,  still  such  a  radiograph 
i-  not  sufficiently  clear  to  be  accepted  as  anything  more  than  corrobora- 
tive evidence.  The  radiographer  is  not  the  one  to  decide  whether  an 
operation  H  necessary  or  not. 

The  w-titriclcx  of  flic  lira  in  were  shown  to  be  full  of  air  in  a  traumatic 
case  radiographed  by  \V.  II.  Luckett'  (Figs.  f)(i2  and  ,:)i  •;•>). 

The  diagnosis  was  confirmed  by  an  autopsy. 

A'-ray  Examinations  for  Foreign  Bodies  in  the  Cranial  Cavity. 
-  The  exact  locali/.at  ion  of  a  bullet  or  other  foreign  bodv  will  enabl" 
the  -tirgeon  to  judge  of  tin-  desirability  of  an  operation  for  its  removal. 

;!io\ 


part    of   the   head    resting  on    it;    the   lube   diamet  ricall  v 
\vill  be  better,  however,  ton-'1  the  author's  lateral  plate- 
f-ribcd  on  p.  <)74.      This  enable.-  one  to  make  a  preliminary 
examination   and  turn  the  patient's   head  into  the  position 


• 


THE    Z-KAY 


905 


at  which  the  foreign  body  will  be  nearest  the  plate.  It  is  very  desirable 
to  mark  a  small  spot  on  the  head  with  nitrate  of  silver  just  where  the 
image  of  the  foreign  body  is  seen.  This  is  done  while  looking  through 


l-'ig.  562. — Air  in  the  ventricles  of  the  brain.  Lateral  view.  The  arrows  outline 
the  distended  ventricles.  The  large  round  white  shadow  is  the  right  anterior  horn  (W.  H. 
Luckett). 

the  fluoroscope.     A  similar  mark  may  be  required  in  some  cases  at  the 
opposite  side  of  the  head  to  indicate,  the  direction  of  the  tube.     Then 


FIJI.  .">(>:>. —  Air  in   the  ventricles  of  the  brain.      Anteroposterior  view.      Two  lateral 


ventricles  distended  with  air.      Small  round  white  shadow  just   between  and  below  is  th< 


third  ventricle  also  distended  with  ai 


Arrows  indicate  the  positions  (\Y.  II.  Luckett). 


the  plate  in  a  stereoscopic  holder  is  placed  between  the  patient's  head 
and  the  vertical  board  of  the  lateral  plate-holder,  and  the  radiograph  is 
made. 


90G 


MEDICAL    KLE<  TRieiTY    AND    RONTCKN    KAYS 


St 


Localization. — A  single  radiograph  of  a  foreign  body  in  the-  cranium 
does  not  indicate  the  exact  depth  at  which  the  body  is  located.  Clear- 
ness and  apparently  natural  size  of  the  image  indicate  proximity  to 
the  plate;  while  vagueness  and  enlargement  indicate  that  the  foreign 
body  is  at  a  distance. 

In  certain  cases  two  separate  radiographs  may  be  made  in  directions 
almost  at  right  angles  with  each  other.  The  cranial  landmarks  shown 
in  the  radiographs  may  enable  one  to  locate  the  foreign  body  ut  the 
intersection  of  two  definite  lines.  It  is  alwavs  better,  however,  to 
mark  both  of  these  lines  by  two  pairs  of  nitrate  of  silver  stains  applied 
under  the  guidance  of  the  fluoroscope. 

The  two  radiographs  at  a  right  angle  are  not  practicable  or  desirable 
in  some  locations  in  which  a  foreign  bodv  ma}'  lie.  In  s;uch  a  case 
stereoscopic  radiography  may  be  useful. 

Strt'coxr'npir  knil  ini/ru  phij  of  Foreign  Bodtc*  t//  the  Cranium. — The. 
iscopic  plate-holder  may  be  flat  upon  the  table  with  the  patient's 
head  resting  upon  it  and  tube  above:  or  the 
author's  lateral  plate-holder  may  hold  the 
stereoscopic  plate-holder  in  a  vertical  position 
while  the  patient  lies  with  the  proper  part  of 
the  head  in  contact  with  the  plate-holder,  and 
with  the  tube  diametrically  opposite.  One 
radiograph  is  made  with  the  tube  in  a  certain 
position  and  then  the  plate  is  removed  from 
the  plate-holder  and  another  plate  inserted 
in  exactly  the  same  position.  The  patient 
has  held  perfectly  still  during  this  change. 
The  .r-ray  tube  is  then  shifted  '2]  inches 
to  either  side  and  another  radiograph  is 
made.  A  pair  of  such  pictures  examined 
with  a  stereoscope  gives  a  combined  image 
in  which  the  perspective  is  shown.  Quite  an 
idea  may  be  obtained  as  to  the  distance  of 
the  foreign  bod}'  from  the  plate,  but  no  exact 
measurement . 

Localization  ////  Trian(Jiilation.—T\\\x  is  used  in  the  same  cases  that 
are  -unable  for  stereoscopic  radiograph}' and  gives  much  more  accurate 
results. 

made  with   the  head  and   the  plates  in   the  same 
mean-    of   a    stereoscopic    plate-holder,  but    with   the  tube 
her  side  for  a  distance  of  o  inches  after  the  first   picture. 
anticathode  being  at  a  distance  of  21  inches  from  the  plate  the  dis- 
•e  that  the  iniau'e  of  the  foreign  body  is  shifted  enables  one  to  read 
i  t  he  aut  hor's  table,  page  807.  its  distance  from  1  he  plate  (Fig.  504). 
po-itioii  of  the  foreign  body  may  be  determined  in  this  way  to  the 
i  ion  of  an  inch. 

fhe  details  of  a  more  exact  method  of  localization  by  triangulat ion 
lives  the  use  of  cross-wires  marking  exact]}"  the   same  position  on 
two  -ucce--ive  plate-,  and  also  a  solid  metal  object   fastened  upon 
iead   at    a    portion   in   contact    with   the   plate.      This  is  more  fully 
1   in   the  -ertion   upon   the  radioura ] ihic   localization  of  foreign 
orbit.      McKenzic   Davidson's   localizer  is  also  excellent 


THE    X-RAY 


907 


In  some  cases  it  is  sufficient  to  use  only  one  plate,  making  two  sepa- 
rate exposures  with  the  tube  in  two  different  positions.  This  produces 
two  separate  images  of  the  foreign  body  on  the  same  plate,  but  the 
rest  of  the  picture  is  somewhat  blurred.  Such  a  radiograph  (Fig.  50oj  was 
taken  of  an  empty  skull  with  the  .r-ray  tube  in  two  different  positions. 
Two  plates  were  used,  but  were  in  identical  positions.  If  they  are  now 
superimposed,  the  brass  springs  and  screws  which  hold  the  jaw  in  posit  ion 
show  double  images.  The  screw  on  t  he  side  nearest  t  he  plate  casts  t  wo 
shadows  which  almost  coincide,  while  the  screw  on  tin  side  of  the  skull 
opposite  the  plate  casts  two  shadows  which  arc  at  a  considerable  distance 
apart.  A  calculation  based  upon  the  distance  between  the  two  images, 
the  distance  from  the  plate  to  the  tube,  and  the  distance  bet  ween  the  t  wo 
different  positions  of  the  tube  would  give  the  distance  from  the  plate 
to  the  screw. 

Two  cases  of  .r-ray  localization  of  bullets  in  the  cranium  and  their 
successful  removal  were  reported  as  early  at  IS!)!)  by  Lucas.1 


An  interesting  skiagraph  by  AY.  A.  C.  Ilammel  was  published  by 
Gamble  and  Tiffany,"  showing  a  chiml  4\  inches  long  which  had  been 
projected  violently  into  a  man's  neck  and  had  remained  concealed  in 
the  tissues  for  sixty-nine  days.  The  radiograph  showed  that  the  lower 
end  of  the  chisel  rested  against  if  not  in  the  bod}"  of  the  fifth  cervical 
vertebra,  while  the  upper  end  extended  an  inch  above  the  level  of  the 
hard  palate.  It  had  evidently  gone  downward  and  backward  through 
the  upper  jaw  bone. 

A  case  in  which  an  .r-ray  examination  would  doubtless  have  saved 
life  was  one  which  came  to  the  attention  of  the  author,  though  not  under 
his  care,  before  th:>  discovery  of  the  .r-ray.  The  patient  had  been 
struck  on  the  head  by  a  heavy  piece  of  wood  and  sustained  a  scalp  wound 
which  healed  promptly  and  the  man  seemed  all  right  for  some  weeks, 
but  then  quite  suddenly  developed  symptoms  of  brain  abscess  and  died 
in  a  few  days.  It  was  found  that  a  nail  had  been  driven  into  the  brain 
and  had  broken  off  (lush  with  the  outer  surface  of  the  skull. 

One  glance  with  the  fluoroscope  at  the  head  in  profile  would  have 
revealed  the  presence  of  this  foreign  body. 

A    similar   case    is    reported    by   O'Hanlon,    Coroner's    physician   in 


!H)8  MEDICAL    ELECTRICITY    AND    KONTGEN    KAYS 

New  York  City,  -Ian.  21,  1905.  The  patient  was  treated  at  one  oi 
the  hospitals  for  a  scalp  wound  which  healed  promptly,  but  there- 
after the  man  began  to  have  epileptiform  convulsions.  A  radiograph 
was  made  sonic  months  later  which  showed  a  bullet  lodged  beneath 
the  anterior  lobe  of  the  right  hemisphere  of  thr  brain.  Hut  the  man 
had  left  that  hospital  before  the  plate  was  developed  and  during  the 
entire  eighteen  months  that  he  lived  no  one  else  suspected  even  the 
occurrence  of  a  pistol  wound.  He  died  of  an  abscess  of  the  brain  and 
the  ( 'eroner's  physician  discovered  the  bullet .  The  bullet  itself  appears 
to  have  been  innocuous,  but  a  fragment  of  the  bullet  with  a  sharp  bit 
of  bone  adherent  to  it  set  up  the  irritation  which  eventuated  in  abscess 
of  the  brain  and  deal  h. 

In  a  case  reported  by  \\eiser1  radiographs  showed  a  bullet  lying  in 
ih"  cerebellum.  There  were  marked  symptoms  at  first,  but  the  bullet 
was  not  removed  and  the  patient  became  apparently  perfectly 
well. 

Foreign  Bodies  in  the  Orbit  or  the  Eye  -These  are  usually  of 
small  si/c  and  the  exactness  with  which  they  must  be  located  makes 
its  accomplishment  by  means  of  the  flucrosecpe  alone  require  a  dan- 
gerously long  exposure. 

Hadiographic  localization  is  based  upon  one  of  two  general  principles. 
By  one  method,  not  often  used,  an  anteroposterior  radiograph  is  taken 
upon  a  plate  in  front  of  the  face,  the  tube  being  behind  the  head.  Then  a 
lateral  radiograph  is  made  upon  a  plate  at  the  suspected  side  of  the  face 
with  the  tube-  at  the  other  side.  These  two  pictures  enable  us  to  locate 
t lie  foreign  body  at  the  intersection  of  two  lines.  In  such  a  delicate  organ 
as  the  eye.  small  fract  ions  of  an  inch,  count  for  a  great  deal.  The  general 
topography  of  the  cranial  and  facial  bones,  as  shown  in  the  radiograph, 
does  nol"  afford  sufficiently  minute  exactness  for  this  purpose.  Land- 
marks are  required,  such  as  bit  s  of  lead,  which  some  operators  have  sewed 
fast  at  tin  upper  and  1  he  lower  border  of  1  he  cornea.  The  patient  must 
be  instructed  to  look  straight  ahead  during  the  exposure  to  the.r-ray. 
The  anteroposterior  radiograph  will  show  at  what  distance  the  foreign 
body  lies  from  the  vertical  line  passing  through  these  two  bits  of  lead, 
and  'hi  lateral  radiograph  at  what  distance  behind  the  same  plane. 
Both  radiographs  show  the  level  of  the  foreign  body 

It  is  a  matter  of  saving  t  he  eye,  and  t  hese  bits  of  lead  can  be  attache*1 
without  anv  mjiirv  and  without  pain  if  cocain  is  used.  This  method 
is,  therefore,  perfect  ]v  proper  if  regarded  as  necessarv. 

A  similar  met  hod  is  to  fa. -ten  a  bit  of  lead  on  t  he  out  side  of  the  upper 
eyelid  directly  over  the  center  of  the  pupil.  th<  lid  being  kept-  closed 
by  ;:  bandage.  The  patient  should  be  cautioned  not  to  move  the 


or 


.  p 

on    his  side  facing   the  plate;  and   later  face   up  with   the  plate  at   the 
atlected    side. 

Hie  j:-ray  tube  may  be  enveloped  in  a  shield  with  a  leather  disk  to 
•   HoHoii  Mefl.  Surfi.  Journ..  March  '2'2.  IdOti. 


THK    .r-HAY 


909 


Schonberg's   compression   cylinder  or 
The  .r-ray  tube  should  not  he  entirel 


arrest  the  soft  rays,  or  Alber 
similar  apparatus  may  he  used. 
free. 

The  anteroposterior  picture  is  made  with  the  tuhe  at  the  same  dis- 
tance1 and  position  and  with  the  same  strength  and  quality  of  ray  as 
recommended  for  anteroposterior  frontal  sinus  radiographs. 

The  lateral  picture  is  much  easier.  The  distance  from  the  plate 
to  the  anticathode  should  he  ahout  17  inches,  the  penetration  about 
No.  0  Benoist,  and  the  exposure  about  half  a  minute  with  an  induction- 


Fig,  ofifi. — Localizer  for  foreign  bodies  in  the  eye  and  orbit.      (Sweet  method). 

coil  or  a  fraction  of  a  second  with  a  transformer  or  an  unfluctuating 
converter. 

The  head  should  be  held  perfectly  still.  sand-bags  being  used  if 
necessary. 

Anything  as  large  a.s  a  shot  would  be  easily  located  in  this  way, 
but  smaller  objects,  like  small  splinters  of  steel  or  glass,  might  not  be 
discoverable  in  the  anteropostcrior  image. 

Localization  />//  7Ymm////c///'o/?. — This  is  the  only  method  which  is 
applicable  to  all  cases,  even  those  in  which  it  is  necessary  to  decide 
whether  a  spicule  of  steel  or  glass  is  imbedded  in.  the  sclera  or  just, 
outside  or  inside. 

Sweet's  apparatus  (Fig.   ")()(>)  or  Rowen's  or  Dixon's  may  be  used. 

Th<  principle  is  that  two  lateral  pictures  are  taken  with  one  or  two 
hits  of  lead  held  in  the  same  position  close1  to  the  eye  while  the  tube  is 
moved  laterally.  The  distance  and  direction  of  the  foreign  body  from 
the  one  or  two  hits  of  lead  and  from  two  cross  wires  in  the  two  separate 
pictures  form  the  basis  of  a  geometric  calculation  from  which  the  exact 
position  of  the  foreign  hod\-  is  found.  Charts  printed  by  Meyrowit/., 
of  New  York,  give  the  result  by  a  graphic  process  without  algebraic 
formulas. 

One  of  the-  bits  of  lead  is  held  close  to  the  eye  and  directly  in  front 
of  the  middle  of  the  cornea:  if  the  other  is  used,  it  points  to  the  outer 
border  of  the  eveball. 


1110  MKDH'AL    KLKCTHIC1TY    AND    KONTCKN     HAYS 

Street'*  iniihod  is  to  have  the  patient  lie  face  up  with  the.  heau 
secured  in  an  apparatus  which  includes  also  the  holder  for  the  hits  of 
metal,  and  for  the  .r-rav  tube  and  the  photographic  plate.  It  is  not 
desirable  for  the  patient  to  sit  up  and  hold  the  plate  against  the  side 
of  the  face.  It  would  be  difficult  for  him  to  hold  still  enough  for  the 
first  picture  and  still  more  so  when  it  came  to  removing  the  first  plate 
and  substituting  the  second. 

I)i.ron'x  Ai>i>nr<itnx.1 — This  forms  a  lateral  plate-holder  for  one  4x5- 
incli  plate.  It  uniforms  more  or  less  to  the  shape  of  the  head,  and  is 
provided  with  a  clamp  for  holding  the  head  in  position.  The  patient 
lies  face  up  while  the  plate  is  held  near  the  affected  side  of  the  face  and 
the  tube  is  at  the  opposite  side.  The  bit  of  lead  is  connected  with  a 
head  band  by  which  it  is  held  in  position  a  very  few  millimeters  in  front 
of  the  middle  of  the  cornea. 

])/>/!•(  n'.^  Arrangement.- — This  consists  in  having  the  patient  lie  with 
the  affected  side  of  the  face  resting  upon  a  horizontal  plate,  with  the 
tube  over  the  opposite  side  of  the  face,  and  the  two  bits  of  lead  fastened 
to  a  -tern  whose  heavy  base  rests  upon  the  plate. 

In  all  these  methods  of  localization  by  triangulation  the  first  radio- 
irraph  may  be  made  with  the  tube  in  a  line  with  the  one  or  two  bits  of 
lead,  or  1 ',  inches  to  either  side  of  that  line.  The  second  one  is  made 
with  the  tube  moved  3  inches  laterally,  a  little  above  the  line  of  the 
one  or  two  bits  of  lead. 

A  stereoscopic  plate-holder  is  convenient  because  it  enables  one  to 
remove  the  first  plate  and  insert  the  second  without  the  patient  moving. 
IT  is  not  used  because  of  any  necessity  that  the  two  plates  should  be 
placed  in  absolutely  the  same  position,  so  that  the  picture  would  come 
on  exactly  the  same  part  of  each  plate,  as  in  stereoscopic  radiography. 
All  that  is  required  for  th;  present  purpose  is  that  the  successive  plates 
shall  lie  in  the  same  plane.  Some  operators  prefer  to  take  both  pictures 
upon  different  parts  of  the  same  plate  to  prevent  their  ever  becoming 
separated  or  mixed  up  with  radiographs  of  some  other  case.  H<>avy 
I'-ad  is  placed  over  one  part  of  the  plate  while  the  first  picture  is  made; 
then  the  position  of  the  plate  is  changed  and  the  lead  placed  over  the 
first  part  of  the  plate  while  the  second  picture'  is  made.1"1 

Tlie  eye  .-h.oiild  be  fixed  in  position,  and  if  it  is  open  this  is  best 
accomplished  by  placing  a  bright  object  at  the  proper  position  for  the 
patient  to  look  at.  or  he  may  look  at  the  reflection  of  his  own  eye  in  a 
Mi'".ll  mirror.  Another  way  is  to  place  the  center  bit  of  lead  against 
the  eyelid  over  the  middle  of  the  cornea  with  the  eye  closed.  There 
i.~  then  very  little  probability  of  the  eye  moving. 

I  lie  tube  may  be  out  in  the  open  air  or  enveloped  m  a  localizing 
-hii-ld  or  a  compression  cylinder  may  be  used.  The  latter  would  not  be 
i"!'  compressing  or  even  for  immobilizing  the  head,  but  simply  for  its 
eiiect  in  cutting  out  secondary  ravs.  The  author's  preference  is  for  a 
locali/ini:  -hield  with  a  sole-leather  disk  to  arre.-t  the  soft  ravs. 

liie  radiograph  i.-  not  a  difficult  one  to  make.  The  distance  from 
Hi  '•  all  ode  to  plate  should  be  about  1^  inches;  the  penetration  No.  G 


THE    X-RAY 


Oil 


Benoist  for  metallic  objects,  or  No.  4  Benoist  for  bits  of  glass,  and  the 
exposure  from  fifteen  seconds  to  a  minute. 

Detail*  of  Localization  hi/  Dijon'*  Apparatus. —  The  patient  lies  face 
upon  the  table  with  head  clamped  to  the  lateral  plate-holder  after  the 
head  has  been  squared  by  a  special  apparatus.  This  is  to  make  the 
sagittal  plane  of  the  head  parallel  with  that  of  the  photographic  plate 
(Figs.  o(>S  and  /)(><)). 

It  has  been  found  that  straps  are  not  required  to  immobilize  the 
patient's  head.  This  object  is  better  accomplished  by  an  aluminum 


Fig.  -r)fi7. — Radiograph  bv  Dixon   with  his  apparatus  for  localizing  foreign  bodies  in  the 


bar  which  is  passed  across  for  the  patient  to  bite  on  and  is  firmly  fastened 
in  place.  A  small  sand-bag  makes  an  adjustable  cushion  for  the  head. 

The  tube  is  placed  with  its  antieathode  at  a  measured  distance  of 
just  .")()  cm.  from  the  plate  and  is  normal  to  the  plate  at  the  intersection 
of  th<>  cross  wires.  This  direction  is  obtained  by  sighting  from  a  brass 
notch  behind  the  plate  and  through  the  intersection  of  the  wires. 

Fixation  of  the  eye  is  obtained  by  having  the  patient  look,  chiefly 
with  t  he  uninjured  eye,  of  course,  at  a  small  wooden  ball  suspended  about 
It)  inches  above  the  exact  center  of  the  cornea  of  the  injured  eye.  This 
centering  has  been  obtained  by  lowering  the  wooden  ball  to  within  a 
short  distance  of  the  injured  eye  and  then  adjusting  the  cross  bar.  from 
which  it  is  suspended,  until  the  ball  is  directly  over  the  center  of  the 
cornea,  and  then  pulling  it  up  into  position. 

The  marker  is  a  drop  of  solder  on  the  end  of  a  brass  wire,  which  is 
fastened  to  an  adjustable  rod  attached  to  the  patient's  head  by  a  hand 
just  like  a  forehead  mirror  for  laryngoseopic  or  aural  examinations. 
It  is  fastened  directly  in  front  of  the  middle  of  the  cornea  and  at  a 
measured  distance.  '_'  or  3  mm.,  from  it. 


MKDICAL    KLKCTHK  ITY    AND    ROXTGEN    KAYS 


alizinsz  foreign  bodies  in  the  eve.       Safetv  to  operator 


r-niv  tul>e  should  he  pndosod  in  a  protective  shield 


.  ."iiiv — Dixon's  method 

and  patient  reqture>  tha 


'    •       Sliuwiiiu   fixation  of  the  eve  in  Dixon's  method  of  localizinn  foreign  I 


in.-ikiiii!  the  first  cxpo-urc  the  .r-i'ay  tube  i<  lowered  vertically 


I'lii-  mean-  liack\sanl  with  reference  to  the  patient  who  is  Ivinj 


THE    X'-KAY  913 

After  the  first  exposure  the  tube  is  raised  (1  cm.  or  1o  a  point  3  cm. 
above1  its  normal  position  and  the  second  exposure  is  made  upon  another 
plate. 

The  calculation  of  the  result  requires  only  two  preliminary  measure- 
ments: the  distance  from  the  plate  to  the  anticathode,  and  the  distance 
from  the  coritea  to  the  bit  of  lead. 

Quotations  from  a  case  in  Dr.  Dixon's  monograph  show  how  the 
localization  is  made.  The  distance  from  the  anticathode  to  the  plate 
"was  51.5  cm.  and  that  from  the  cornea  to  the  bit  of  lead,  'J  mm. 

Take  a  piece  of  drawing  paper  and  draw  a  line,  a,  right  across  it, 
which  indicates  the  normal  line  at  the  intersection  of  the  cross  wires. 
A  line  marked  b,  at  a  right  angle  to  a,  and  at  a  distance,  in  this  par- 
ticular case,  of  51.")  cm.,  will  indicate  the  vertical  line  along  which  the 
.r-ray  tube  is  moved.  A  line,  c,  also  at  a  right  angle  to  this,  near  one 
end,  will  represent  the  plane  of  both  the  first  and  second  photographic 
plates. 

The  line  a  on  the  photographic  plate  represents  the  cross  wire  which 
is  parallel  with  the.  length  of  the  patient's  body,  and  the  line  b  the  wire 
at  right  angles  with  it. 

A  measurement  is  made  on  the  first  plate  of  the  distance  from  the 
line  <i  to  the  point  of  the  lead  indicator.  This  distance  is  measured  off 
on  the  diagram  from  the  line  <i  along  the  line  b,  and  the  point  reached 
is  marked  o. 

Another  measurement  is  made  on  the  first  plate  of  the  distance  of 
the  foreign  body  from  the  line  <i  and  the  result  of  this  is  marked  on  the 
diagram  as  the  point  .r. 

Similar  measurements  on  the  second  photographic  plate  give  the 
points  o  and  x  on  the  diagram. 

Xow  mark  the  position  of  the  tube  at  the  time  of  the  first  exposure 
at  a  point  Ex.  1  on  the  line  b  at  a  distance  of  o  cm.  from  the  line  a. 
Mark  also  another  point  Ex.  2,  indicating  the  position  of  the  tube  during 
t  he  second  exposure. 

Draw  lines  on  the  diagram  from  Ex.  1  to  x'  and  <>' ;  and  from  Ex.  2 
to  f)  and  x.  The  lines  to  x'  and  .r  will  be  found  to  have  crossed  in  space 
at  a  point  which  is  marked  .r";  and  the  lines  to  />'  and  o  cross  at  o" . 

The  direction  and  distance  of  the  point  x"  from  a  line  drawn  through 
<>"  parallel  with  c  show  whether  the  foreign  body  is  toward  the  photo- 
graphic plate  r  or  toward  the  median  line  of  the  head,  and  at  what 
distance  it  lies  from  the  vertical  axis  of  the  eye. 

Only  one  factor  in  the  localization  of  the  foreign  body  remains  to 
be  determined,  and  that  is  the  distance  above  or  below  the  horizontal 
axis  of  the  eye.  The  distance  from  the  cross  wire  b  to  the  indicator 
should  be  the  same  on  the  two  plates  if  the  tube  and  head  arj  properly 
placed. 

These  two  distances  are  measured  upon  the  line  r  in  the  diagram. 

Lines  are  drawn  from  the  two  points,  .r3  and  <>'''.  thus  found  to  the 
middle  point  of  the  line  b.  The  intersection  of  the  line  passing  to  /' 
with  the  line  drawn  through  .r".  parallel  with  the  line  r.  shows  the 
local  ion  of  the  ioreign  boil}'  upon  a  horizontal  plane,  while  the  inter- 
section of  a  line  dra\vn  to  <>'"  with  a  line  drawn  through  o"  and  parallel 
with  the  line  r,  shows  the  position  of  the  indicator  on  the  same  plane. 

Plotting  these  measurements  upon  the  chart,  in  this  particular  case, 
we  measure  off  10  millimeters  back  from  the  center  of  the  cornea,  and 


MEDICAL    KI,K( THH  ITY    AND    KONTGEN    KAYS' 


8  millimeters  below  the  hori/ontal  plane,  and  (>  millimeters  to  the 
temporal  side,  and  thus  indicate  the  point  of  location  of  the  foreign  body 
in  rhc  eye.  The  method  of  location  by  triamrulat  ion  is  due  partly  to 
McKenzie  Davidson  and  partly  to  Sweet.  Vox,  Hulen.  Dixon.  and  Bowen. 
In  making  all  the  different  measurements  one  should  be  careful  to 
use  the  same  part  of  the  miaue  of  the  foreign  bod}-,  if  the  latter  is  larger 
than  a  ni"re  dot.  It  is  easy  to  see  how  errors  of  a  distance  equal  to  the 
diameter  of  the  foreign  body  miu'ht  result  if  the  same  portion  were  not 
selected  for  all  the  different  measurements. 


odv    Kiiis.   ">7(>  and   ~>~  1  i  wa.-  so  large  that   separate 


mea.-ur<-inent ,-  were  made  to  locate  its  different  extremities. 


I      •  '.  -    ••    .  ,,,:t,t    •...;,- 

hi  irk    !  n  iln    ecu!  >T  ( il    f  i  il'[ic;i 

; !    -i  [c  Hi'  ecu!  i-r  of  ci  ii'ii'-.i 
'!.,     ..        •  .j-tr,,,    '/,/«:,, 

II      cc-ntiT   i:t'    ci  inil-!l      ... 

T   • 


•}.o  mm 


1 

..9.5     " 


915 


A  radiographic  examination  should  lie  made  in  every  case  of  injury 
to  the  eye  by  a  foreign  body  when  there  is  reduced  visual  acuity,  whether 
there  is  a  distinct  history  of  pos.-ible  penetration  by  a  foreign  body 
or  not . 

The  foreign  Ix.dy  may  possibly  be  so  small  that  its  shadow  escapes 
detection,  but  this  is  unlikely  in  an  excellent  radiograph. 

Allowance  must  sometimes  be  made  for  myopia  or  hypermetropia 
in  calculating  the  position  of  the  foreign  body.  The  variation  from 
the  normal  diameters  of  the  eve-ball  mav  have  to  be  considered. 


radiograph   in    Mir    Inrali/atinn   of   tlie  forricrn  body  in    tin1   eye  (see 


DC  Scmveinit/.1  has  observed  slight  variations  which  make  it  difficult 
to  say  wlu thcr a  bird-shot  is  cither  at  or  immediately  outside  or  inside 
the  sclera. 

The  anteroposterior  diameter  of  a  normal  eye  varies  from  L'O  to  125 
millimeters,  and  in  one  case  in  which  Dixon  located  the  sh.m  just  outside 
the  sclera  Dr.  Marble  found  ii  to  be  ju-t  inside.  The  man  measured 
li  t'cci  _'  inches  in  height  and  had  an  eye  '_'(>  millimeters  in  diameter. 
It' t  his  fact  had  been  taken  into  consideration  the  location  would  probably 
have  been  c<  irreet . 

Stilling  states  that  variation  in  the  diameter  of  the  eye-ball  is 
independent  of  errors  of  refraction  and  that  a  myopic  eye  of  -1  D.  may  be 
actually  >horter  than  a  hyperopic  eye. 

'Journal  Am.  Mcd.  Assw..  Aug.  11.  1!KM>.  p.   122. 


MKIMCAL    ELECTRICITY    AND    KoXTCKN    HAYS 


The  .r-ray  may  he  used  to  ascertain  whether  a  sliot  which  at  first  has 
been  lodged  in  the  vitreous,  or  elsewhere,  has  become  loosened  and  fallen 
onto  the  ciliary  body.  Such  a  change  in  position  might  be  followed  by 
iridocyclitis.  Cases  have  been  reported  by  Marple1  in  which  the  x-ray 
has  shown  that  there  has  been  a  double  perforation  of  the  eye-ball  by  a 
shot,  the  latter  having  gone  completely  through  the  eye-ball  and  being 
lodged  in  the  tissue  outside.  The  diagram  reproduced  in  Fig.  .">72 
represents  Dixon's  chart  for  use  in  these  cases. 

Radiography  of  the  Ear  and  the  Mastoid  Cells. — The  classical  pic- 
ture of  this  region  is  made  in  the  method  elaborated  by  Lange.-'  The 
direction  of  the  ray  is  from  the  .r-ray  tube,  placed  on  the  opposite  side 
at  a  point  2."r  above  the  horizontal  line  between  the  auditory  meati  and 
20  behind  that  line.  The  plate  is  pressed  against  the  affected  side  of  the 


7j       Week:-  ami  Di.xon'.-  modififation  of  Swe-ei'.-  cluiri  for  plotting  location  of  for- 


tlii  li(jilic.-  in  the  <-yc  jind  oil.n 


head,  the  ear  beinii  bent   forward.      This  ^ives  a  picture  of  one  mastoid 
n-uion   and   includes  the  lateral  sinus.      Another  .-ymmeti'ic  radiograph 

•  i  !n-  made  of  the  opposite  nde  tor  coni])arison. 

A   po.-itiou  em|)lo\-ed  by  \\iii.  II.  Stewart"  i>  with  the  patient   lying 

ip  and  with  a  -omewhat  raised  platform  under  the  head  so  that  the 

.!    |-e.-ts    upon    the   plate.      The  lube  i>  placed   above  the  head,  but 

\  ~t      bad..      Thi-    ui\'es    a    simultane<»us    \ic\\'    oi    both    mastoid 

ill  iwn  to  the  tip  of  t  he  ma. Moid  processes.      The  aut  hor  suggested 

in  ii  .  ••.!-- ion  that  Stewart'.-  po.-ilion  could  lie  u.-ed  to  obtain  better 


TIIK    X-RAY  917 

single  pictures  by  displacing  the  tube  first  to  one  side  and  then  to  the 
other  for  the  second  plate. 

The  niastoid  cells  of  both  sides  show  very  well  in  an  anteroposterior 
radiograph  made  with  the  tube  behind  and  in  the  median  line  while  the 
plate  is  in  front.  The  greater  length  of  the  plate  should  be  transverse. 
The  anticathode  of  the  tube  should  be  on  a  continuation  of  the  line 
from  the  external  auditory  meatus  to  the  tip  of  the  nose,  so  as  to  make  the 
shadow  of  the  malar  bone  fall  above  that  of  the  niastoid  cells.  The 
picture  is  a  difficult  one  to  make,  and  is  made  as  follows:  Penetration, 
7  Benoist ;  distance  from  plate  to  anticathode,  19  inches;  exposure  about 
sixty  seconds  with  an  induction-coil  or  about  one  second  with  a  trans- 
former or  an  unfluctuating  converter.  An  intensifying  screen  will 
reduce  the  time  of  exposure  to  one-tenth,  and  if  several  pictures  are  to 
be  made1  the  element  of  x-ray  dosage  becomes  important.  A  diaphragm 
and  a  sole-leather  screen  are  desirable.  The  diaphragm  should  be  of 
non-conducting  material,  so  that  it  may  be  in  immediate  contact  with 
the  x-ray  tube  and  give  a  wide  angle  of  radiation. 

The  niastoid  cells  and  the  middle  and  internal  ear  are  shown  very 
well  in  a  radiograph  made1  with  the  plate  at  the  affected  side  of  the  head 
and  the  tube  at  the  opposite  side  in  the  continuation  of  a  line  passing 
through  the  head  an  inch  above  both  external  auditory  nicati. 

The  plate  is  to  be  studied  by  transmitted  light  in  a  negative  ex- 
amining box.  Air  cells  appear  dark,  which  is  changed  to  light  if  the 
cells  are  full  of  pus. 

The  picture  is  not  very  difficult,  although  the  plate  may  be  a  little 
thin  or  faint. 

X-ray  Diagnosis  of  Tumors  of  the  Pituitary  Body. — This  is  a  disease 
which  often  causes  absorption  of  the  posterior  clinoid  processes  and 
enlargement  of  the  sella  turcica.  A.  J.  Giordani  has  made  a  number  of 
successful  diagnoses  of  this  condition  from  radiographs. 

The  radiograph  should  be  taken  laterally,  with  the  normal  ray  pass- 
ing directly  through  both  external  auditory  meati  and  with  the  anti- 
cathode  about  19  inches  from  the  plate.  The  x-ray  should  be  about 
No.  7  Benoist,  and  the  exposure  will  vary  from  forty  seconds  with  an 
induction-coil  to  a  fraction  of  a  second  with  a  transformer  or  an  unfluctu- 
ating converter.  A  diaphragm  or  cylinder  improves  the  definition. 

Examination  of  the  Teeth  and  Maxillae. — One  of  the  most  im- 
portant applications  of  the  x-ray  is  in  dentistry.  The  greater  density 
of  the  teeth  makes  them  show  very  well  in  contrast  with  the  less  dense 
substance  of  the  jaw,  and  with  a  certain  quality  of  ray  the  tooth  itself 
is  transparent  and  its  pulp-cavity  and  root-canals  may  be  studied  and 
even  pulp-stones  may  be  discovered.  One  of  the  conditions  studied  is 
the  existence  and  position  of  unerupted  teeth,  or,  what  is  equally  im- 
portant, the  fact  that  the  germ  of  the  mis.-ing  tooth  is  absent  altogether 
Figs.  .~>7o-">77).  Another  is  the  extent  to  which  softening  and  decay 
have  taken  place1  in  a  tooth.  Fig.  o~S  shows  an  upper  central  incisor 
in  which  a  cavity  at  a  considerable  distance  above1  the  gum-line  was  dis- 
covered and  filled  by  Dr.  ('has.  ('.  Allen,  of  Brooklyn.  A  couple  of  years 
later  he  sent  the1  patient  tome  suffering  from  indefinite  slight  sensitive- 
ness in  the1  sanu1  tooth.  The1  picture  showed  an  area  of  softening  ex- 
tending far  beyond  the  limits  of  the  filling,  and  indicating  probably  the 
destruction  of  the  nerve.  Acting  on  my  advice.  Dr.  Allen  pressed  the 
gum  far  enough  back  to  get  at  this  part  of  the  tooth,  found  very  little 


918 


MKIHCAL    KLKCTHICITY    AND    RONTGEN    HAYS 


I,  Fiierupted  upper  bicuspid   tooth.      Apparatus  making  a  space   for  it; 


Ii,  port  ion  of  lower  jaw,  >howinii  presence  of  unurupted  permanent  teeth  in  a  case  in  which 


all  the  temporary  teeth  \\ere  persistent  at   the  a<;e  oi   twenty  years. 


Fin.  ~~,-\. — Uneniptod  upper  central  infisor.  l-'ij-r.  •"'>• — Persistent     temporary    lower 

The  tooth  itself  bent  and  rotated.  molar   with   uncrupted   bicuspid. 


l-'ij.'  .")7s.  —Caries  of  t !,..  root  of  upper 
centrrd  inci  or.  IMack  ma-~e-  are  fillirit:-: 
8e\-nral  beilitr  at  the  proximal  ancles 
(where  two  adjacent  teeth  are  in  contact.). 


T  if;.  ."»7'.t.       Kxtensive     caries     of     the 
ami    root    of    ujiper    central    inci>or. 
had   l'»\    been  >l  i.-pect  C(  I . 


THE    .T-KAY 


of  the  nerve  and  removed  thai,  excavated,  and  filled  a  very  large  cavity 
in  time  to  save1  the  tooth  from  breaking  off. 

The  condition  of  root-fillings  and  pivot  teeth  is  easily  determined 
(Figs.  580-580 ). 

In  some  cases  an  unerupted  tooth  is  the  cause  of  anxiety  simply  a>  to 


tnclar  has  excellent   pivot   toot! 


bicuspid     rout    shows    marked    absorption 


the  proper  regulation  of  the  teeth  to  accommodate  it  when  it  comes.  In 
other  cases  the  unerupted  tooth  is  lying  in  a  faulty  position  and  causing 
harm  in  that  way.  Fig.  o8(\  (young  lady  of  seventeen,  patient  of 
Dr.  J.  S.  Hasbrouck)  shows  an  unerupted  wisdom  tooth  growing  in  a 


5N2. —Crown    and    bridge  work 


direction  almost  at  a  right  angle  to  the  molar  tooth  in  front  of  it,  and 
causing  the  sudden  appearance  of  very  severe  pain,  which  had  con- 
tinued without  interruption  for  three1  days.  The  cause1  of  the  trouble 
was  suspected,  but  the  fact  that  the  lower  canine  tooth  on  the  same  side 


MKD1CAL    ELECTRICITY    AND    KONTCKN    KAYS 


had  not  erupted  made  the  .r-ray  examination  indispensable.  A  glance 
at  the  jaw  with  the  author's  dental  fluoroscope  showed  the  faulty  di- 
rection of  the  wisdom  tooth  and  the  entire  absence  of  tin1  germ  of  the 
missing  canine,  and  this  was  confirmed  by  the  radiograph. 


Flu.  .">."). —  Excellent    root-filline    in    first 


In  a  yonn.tr  .trirl  (a  patient  of  Dr.  ('lias.  O.  Kimball)  the  left  upper 
lateral  incisor  had  betrun  to  bo 'everted  and  also  rotated  on  its  axis. 
A  radiograph  showed  this  to  he  due  to  the  faulty  position  of  the  un- 
erupted  canine,  which  as  it  developed  was  driving  directly  against  the 
roi it  of  the  incisor. 

Tin  Author'*  Dental  Flnnroxcopc. — All  the  above  conditions  are 
easily  seen  with  the  author's  fluoroscope  (Fisr.  .~>S7),  published  in  the 
International  Dental  Journal.  .Inly'.  I'.HM.  This  is  shaped  somewhat  like 
a  dental  mirror  or  a  laryngoscope,  but  instead  of  a  reflect  in»;  has  a  flu- 


oro-copic  surface  on  both  sides,  so  that   either  the  side  toward  or  away 

IP  PHI  the  .r-my  may  be  looked  at.      It    i<  placed  inside  the  mouth,   and 

the   room   beintr  darkened,  the  .r-ray  tube  i-  placed   near  the  side  of   the 

face.       1  he  niKiire  of    the   teeth  and   mni-  and  e\'en  ol    the  structure  of 

iw   -,    inch    beyond    the   ;ipex   of    the  rool-  -lio\\<   very    well.      The 

tube    -houM    be  of   r;ither   low   \-acuiiin.  iv-i-t;incr   i_>   inches  and  radio- 

1:  the  current    much  lcs>  than  tor  ;i   radiotrmph,   the  anticathode 

from    the    face,    and    the   expo-lire   o)il\    ;i    very    few    seconds. 

l'o|     ii ;-'  ;i  \\.-i  >.    I  he    presence   ;illd    position    i  it    the    Ulienipted    tooth    11KIV    be 

;•  ii  '  '   a  irlalice,  and  tin-  i>  entirely  -;ite  ;md  may  sullice  for  the 

wholi  tion   or  may  serve  a-  a   s^uide   in   i;d<in^  the  radiograph 

Irom   the  ino-i    advanta^eou>  point   of  view.       I'.ut   ;i   piolonticd  -tudv  of 


THK    .r-KAY  \)2l 

the  fluoroscopic  image  is  as  dangerous  here  as  elsewhere.     The  study  of 
detail  should  always  be  from  the  radiograph. 

The  Author's  Maynifyiny  Fluoroscope  (Fig.  588). — This  is  a  small 
trumpet-shaped  metallic  apparatus,  about  4  inches  long,  closed  at  tin; 
large  extremity  by  a  fluoroscent  screen  with  its  coated  surface  inside. 
The  smaller  extremity  has  a  flaring  rim,  which  fits  closely  over  one  of 
the  observer's  eyes  when  in  use,  so  as  to  exclude  every  particle  of  light. 


Fi^.  .")>(. — Tousey's  dental  fluoroscope.       Its  use  is  extremely  dangerous  to  the  operator 
and  has  been  abandoned  by  the  author. 

There  is  a  magnifying  lens  in  this  end,  which  can  be  moved  back  and 
forth  so  as  to  focus  the  vision  of  the  observer  accurately  upon  the 
fluorescent  screen,  just  as  a  jeweler's  lens  does  upon  his  work.  This 
fluoroscope  is  held  close  up  against  any  part  to  be  examined,  and  en- 
ables one  to  see  details  which  are  quite  undiscoverable  in  the  ordinary 
large  fluoroscope. 

It  may  be  used  with  advantage  in  dental  fluoroscopy,  applied  to  the 
outside  of  the  affected  side  of  the  face  while  the  tube  is  at  the  opposite 


— Tousey's  mairnifyinir  fluorosco 


side.  The  lateral  aspect  of  the  upper  jaw  is  accessible  in  this  way  for 
the  study  of  the  antrum,  the  alveolar  process  and  alveoli,  and  the  teeth. 
The  latter  are  seen  best  with  the  tube  at  a  lower  level,  so  as  to  shine 
under  the  opposite  teeth  and  then  throuirh  the  roof  of  tin4  mouth  on  the 
affected  side. 

A  >ingle  glance  at  the  fluoroscope  will  -how  that  the  vacuum  should 
be  medium  or  low.  With  a  fairly  high  decree  of  vacuum  the  roots  of  the 
teeth  present  hardly  any  contrast  with  the  structure  of  the  jaw.  Quite 


922  MKDICAL    KI.K(  TKKITY    AND    RONTCKN    KAYS 

a  fair  derive  of  intensity  is  required.  The  operator's  face  is  neces- 
sarily so  near  the  x-ray  tube  in  making  this  examination  that  reason- 
able precautions  must  !>e  taken  to  prevent  injury.  The  chief  one  will 
l>e  the  use  of  the  shield  with  a  sole-leather  disk,  limit  ing  the  .r-ray  to  a 
small  area  and  arresting  the  soft  rays,  \vhich  are  the  ones  likely  to  affect 
the  operator's  face.  The  use  of  lead-glass  spectacles  is  desirable  to 
protect  the  eyes.  The  hand  should  be  protected  by  gloves  opaque  to 
the  .r-ray.  Kven  with  all  these  precautions,  the  examination  subjects 
the  operator  to  too  much  exposure  to  the  .r-ray  to  render  it  desirable  as 
a  routine  method.  The  presence  of  a  "nasal"  tooth,  which  might 
escape  observation  by  ordinary  radiographic  methods  of  study  of  the 
teeth,  will  be  detected  at  once  by  this  method.  It  is  similar  in  the 
result-  yielded  to  the  ordinary  lateral  radiograph  of  the  whole  face  upon 
a  plate  placed  at  the  affected  side. 

Denial  iluoroscopy  is  chiefly  useful  in  detecting  the  presence  and 
position  of  unerupted  teeth.  It  is  not  so  useful  as  radiography  for  the 
study  of  structural  details  and  is  exceedingly  dangerous  to  the  operator. 

Salvini1  described  a  lens  fluoroscope  resembling  the  author's  mag- 
nifying tluoroscope. 

Dental  Radiography. — For  most  cases  the  picture  is  produced 
upon  a  film,  plate,  or  sensitized  paper  placed  inside  the  mouth  and 
closely  applied  to  the  inner  surface  of  the  teeth  and  gums.  The  .r-ray 
tube  is  placed  at  a  distance  of  about  13  inches  from  the  anticathocle 
to  the  fare.  It  is  of  very  great  advantage  to  have  the  tube  surrounded 
by  a  localizing  shield  affording  the  operator  almost  complete  protection, 
and  shielding  all  parts  of  the  patient  ex""pt  about  the  mouth.  The 
operator  making  many  such  pictures,  and  sometimes  having  to  hold  the 
iili'i  in  po-it  ion.  would  run  a  serious  risk  wit  hout  some  such  shield,  while 
the  pa:  lent  is  not  affected  in  any  way  by  the  fraction  of  a  minute's  e.x- 
posure  to  a  moderate  radiance.  One  of  the  most  important  facts  in  regard 
to  t he  ./'-ray  is  t he  cumulative  nature  of  its  effect  on  t he  tissues,  and  this 
ha.-  been  productive  of  many  serious  accidents  to  operators  and  experi- 
inenHTs.  Considerable  latitude  in  the  degree  of  vacuum  is  permissible. 
Th-'  resistance  may  be  all  the  way  from  2  to  (.)  indies,  but  where  the  root- 
-  are  TO  be  studied  we  would  not  use  the  lowest  degree  of  vacuum. 

F<IT  lit  (.r/itrt  rirtttyciiologixt  the  author  recommends  4-inch  re- 
si<tance  or  ."(."(  kv.  and  30  ma.  for  four  to  ten  seconds  at  13-inch 
distance.  The  Coolidue  Radiator  Tube  and  a  transformer  are  desirable 
apparat  us. 

/•',,/•  //,,  <!i  nfixt.  ">-inch  resistance,  b.~>  kv..  and  10  ma.  are  preferable 
and  the  duration  four  to  eight  second.-,  i  See  author's  Exposure  Table, 
page.s'jti.i  The  film  for  which  these  are  the  proper  exposure  is  the 
Ka-t  man  positive  cinematograph  film,  made  by  t  he  Kastman  Kodak  Com- 
pany, of  Rochester  and  London.  It  is  many  times  slower  than  the  ordi- 
kodak  film.  The  exposure  for  the  latter  would  be  correspondingly 
shorter,  bui  the  picture  produced  is  not  so  good.  Kastman  rapid  dental 
./•-rav  film,  put  on  t  he  market  in  1912,  is  excellent  and  about  three  times  as 
po-itive  cinematograph  film,  but  does  not  give  quite  the 
Slip-  of  bromid  paper  require  an  exposure  of  fifty  seconds 
h  coil,  and  may  be  developed  in  any  dimly  lighted  room. 
pirture  may  be  made  and  pa-ted  on  a  card  within  five 
r  the  patient  comes  into  the  office.  The  author  made 
i-nlmur-  AfH'i.  Mcd.  Chir.  IVru<:i:i.  I-Vhmarv.  s,  IMHi. 


THK    Z-KAY 


923 


a  radiograph  by  this  process  at  a  demonstration  before  the  First  District 
Dental  Society  of  New  York  State,  December  11.  1<)()4.  The  bromid 
paper  is  excellent  for  everything  except  fine  details,  and  for  these  a  film 
or  a  print  made  from  a  film  is  much  belter. 

The  films  most  useful  are  I1,  by  1  ^  inches  and  come  two  in  each 
packet  ready  for  use. 

Ductile  Film  A/r/.v/x.  --Packets  containing  two  film-  and  having 
a  ductile  metal  back  can  be  bent  to  conform  with  the  shape  of  the  upper 
or  lower  jaw  and  will  retain  that  shape.  This  makes  it  very  much 
easier  to  hold  the  film  in  position,  and  the  .r-ray-proof  metal  backing 
cuts  off  all  secondary  radiation  from  behind  the  film.  This  produces 
an  improvement  in  the  radiographs  which  is  most  evident  in  the  abso- 
lute transparency  of  the  image  of  gold  crowns  and  other  opaque  objects. 


Such  a  packet  U  much  more  securely  held  in  Leach's  film  carrier  than 
a  packet  consisting  of  paraffin  paper  or  the  like.  It  is  made  by  Buck. 

Kadiof/rnph  of  (he  I'pixr  T«-th.  The  upper  teeth  are  not  easy  to 
radiograph  correctly.  Owing  to  the  flatness  of  the  roof  of  the  mouth 
it  is  impossible  to  place  the  film  in  a  plane  parallel  with  the  long  axis 
of  the  teeth.  The  film  is  held  close  against  the  roof  of  the  mouth,  and 
the  inside  of  the  gums  and  the  head  must  be  tipped  toward  the  .r-ray 
tube  !  Fig.  .")()()  i.  If  the  proper  angle  between  the  surface  of  the  film 
and  t  he  direct  ion  of  t  he  .r-ray  is  not  secured  the  image'  of  t  he  teeth  shows 
them  elongated  (like  shadows  about  sunset  •  or  else  foreshortened. 

The  .r-ray  tube  is  placed  so  that  its  anticathode  is  at  a  distance  of 
about  }'•>  inches  from  the  sensitized  film,  and  at  such  a  distance  above  the 
level  of  the  teeth  that  the  image  of  the  teeth  upon  the  film  will  be  as 


'.124 


MKDICAI.    KI.KCTKKTry    AND    KONTCKX     HAYS 


near  as  possible  the  same  length  as  the  teeth  themselves.  If  it  were  pos- 
-il>le  to  have  t  he  film  placed  in  contact  wit  h  the  whole  length  of  the  teeth 
and  their  roots,  it  \vouM  make  little  difference  at  exactly  what  angle  the 
t  u  lie  \vas  placed,  hut  as  t  he  roof  of  t  he  inoiit  h  slopes  away  from  the  roots 
of  t  he  t  eet  h  t  he  film  is  not  placet!  in  contact  with  t  he  roots  or  even  exactly 
parallel  with  the  loim'  axis  of  the  teeth.  Some  little  study,  therefore, 
i-  needed  to  make  t  he  i  ma  lie  an  accurate  represent  a  I  ion  of  t  lie  size  of  the 
tooth.  An  angle  of  '2'2  decrees  will  he  found,  in  a  rough  approximation, 
to  In-  the  cnrrect  aiiii'le  where  the  film  is  pressed  against  the  teeth,  gums. 


UppiT    iiii-i-nt     lei-til    upi.li    ;i    linri/diital    film. 

'   the  mouth.      The  author  ha-  devi-ed  certain  little  film-car-1 

lie  helil  in  the  mouth  in  a  vertical  po-ition.  the  film  then 

i'l    the  lot  in-  axi-  of  the  teeth.      The  Hide  would  have  to 

'  '  e  hori/ontal  level  of  the  teeth  in  order  thai  the  image 

d  tall  upon  the  film.  l>m   it   will  lie  readilv  understood 

'  '     '    '  '  •  ould  lie  1  he  natural  lentil  h. 

'•'•     TU  II,     I 'iinn    n     lltn-r.nnltil    /•'///«.       A    very    good 

'  '  >   anterior  t  wo-t  hird-  of  t  he  upper  jaw  and  of  the 

an  lie  mad*'  I iy  placiim  the  film  liori/ontally 

'-in"   the  lip-  and   teeth   upon  it.      \-\>r  a   picture  of 


THK    .T-KAY 

this  character  tlio  position  of  the  tube  has  to  be  decidedly  higher  than 
when  the  film  is  more  nearly  parallel  with  the  axes  of  the  teeth.  An 
angle  of  45  degrees  will  be  found  about  right.  The  image  of  any  par- 
ticular tooth  is  best  produced  when  the  tube  is  directly  opposite  that 
tooth,  so  that  the  x-ray  shines  through  the  space  between  that  tooth  and 
the  adjacent  ones  and  makes  a  clear  shadow  of  the  tooth  in  question 
without  overlapping  part  of  the  adjacent  teeth.  Two  or  three  teeth  are 
shown  very  well  in  such  a  picture,  while  the  natural  curve  of  the  jaw 
results  in  simply  a  confused  mass  for  the  teeth  beyond.  The  apex  of  tin- 
root  of  any  tooth  is  at  a  somewhat  greater  distance  from  the  film  than 
the  crown  of  the  tooth,  and  consequently  its  shadow  is  a  little  enlarged 
and  a  little  less  distinct  than  that  of  the  crown.  The  enlargement. 
however,  is  not  sufficient  to  interfere  with  the  result.  The  lack  of  dis- 
tinctness is  more  noticeable  when  the  picture  is  of  rather  poor  quality 
than  when  it  is  absolutely  first  class.  A  ray  which  will  give  a  really 
good  image  of  the  tooth  through  the  maxillary  bone  loses  very  little 
of  its  distinctness  in  consequence  of  a  slight  increase  in  distance  between 
the  object  and  the  film.  To  obtain  the  best  possible  definition  the 
author  always  uses  a  small  diaphragm  in  contact  with  the  .r-ray  tube,  and 
makes  certain  that  the  small  picture  shall  include  the  proper  area  by  the 
ust1  of  a  cylinder.  The  latter  is  not  employed  for  compression  or  as  a 
diaphragm,  but  simply  as  an  indication  of  the  direction  of  the  rays. 
Two  films.  2  x  2*  inches,  may  be  simply  wrapped  in  black  paper  and  paraf- 
fin paper  or  sheet  rubber  and  held  horizontally  in  the  mouth  by  the  patient. 
Such  a  picture  requires  a  somewhat  longer  exposure  than  a  picture  taken 
upon  a  film  held  close  to  the  inner  surface  of  the  teeth,  the  difference  in 
time1  being  that,  if  the  latter  picture  requires  ten  seconds,  the  former  should 
be  given  fifteen  seconds'  exposure.  These  are  average  exposures  with 
an  induction-coil,  and  are  reduced  to  one-sixth  and  one-fourth  second  wit  h 
a  transformer  or  an  unfluctuating  current  generator.  The  patient's 
head  does  not  require  to  be  fastened,  although  he  should  be  cautioned  not 
to  move  during  the  exposure.  He  may  be  seated  in  an  ordinary  chair. 

The  usefulness  of  this  method  is  greatest  in  the  upper  jaw,  and 
especially  in  cases  of  suspected  unerupted  teeth  and  a  large  cyst  or  ab- 
scess cavity,  which  sometimes  forms  in  the  upper  jaw.  Taking  con- 
siderable pains  to  have  the  film  held  as  far  back  as  possible  in  the  mouih 
one  may  get  a  very  fair  picture  of  the  antrum,  but  the  roots  of  the  molar 
teeth  are  apt  to  be  somewhat  indistinctly  represented  and  not  to  be 
shown  in  exactly  their  normal  relation  or  length.  The  last  upper  molar 
can  hardly  be  studied  in  this  way  at  all.  Figs.  501  to  500  are  radio- 
graphs made  by  this  method,  and  show  different  parts  of  the  upper 
and  lower  jaws.  For  the  lower  jaw  the  position  of  the  tube  is  at  a  lower 
level  than  the  face,  and  the  chin  rests  in  the  orifice  of  the  locali/ing 
cylinder,  which  is  at  an  angle  of  about  45  degrees. 

In  all  dental  radiography  the  anticathode  should  be  at  least  !••>  inches 
from  the  <kin  to  get  the  best  result.-.  TJie  ant  hor  felt  at  first  that  it  was 
sometimes  necessary  for  the  operator  to  hold  the  film  in  position  by  plac- 
ing his  forefinger  inside  the  patient's  mouth.  The  finger  itself  was  sup- 
posed to  be  protected  by  the  fact  that  the  ray  has  to  shine  through  the 
patient's  face  first,  but  the  re-t  of  the  hand  i-  apt  to  be  directly  exposed 
to  the  ray.  The  protective  lilove-,  in  which  some  >uch  substance  a> 
barium  or  lead  oxid  render  them  opaque  to  the  .r-ray.  were  used,  bin 
the  tip  of  the  forefinger  of  each  one,  and  possibly  the  thumb,  were  cut 


920 


MEDICAL    ELECTRICITY    AND    KONTGEN    HAYS 


TIII-:  .C-HAY  927 

away.  This  may  be  done  in  such  a  way  as  to  leave  the  dorsum  of  the 
thumb  and  forefinger  protected  by  the  glove  while  the  palmar  surface 
is  free.  A  .better  way  in  cases  where  it  is  practicable  is  to  hold  one  edge 
of  the  film-packet  in  a  pair  of  forceps,  and  in  that  way  hold  it  in  proper 
position  inside  of  the  patient's  mouth.  This  will  enable  the  operator 
to  use  gloves  which  have  not  had  the  fingers  cut  away,  and  also  to  have 
his  hands  beyond  the  range  of  the  opening  of  the  locali/ing  shield. 
It  will  be  difficult  for  the  operator  to  hold  the  film  absolutely  still  for 
the  necessary  length  of  time,  and  this  difficulty  is  added  to  in  some  cases 
by  involuntary  motions  on  the  part  of  the  patient.  The  only  place  where 
the  author  has  found  this  method  at  all  easy  is  for  the  lower  molar  and 
bicuspid  teeth.  It  is  better  and  safer  for  the  patient  to  hold  the  forceps 
after  gently  closing  the  mouth. 

The  Author  *  Hand*  Injured  (>i/  Dental  Radiography. — The  practice 
of  holding  the  films  in  position  proved  exceedingly  dangerous  to  the 
operator,  who  has  to  do  it  many  hundred  times,  and  left  the  author  with 
incurable  keratoses  of  the  fingers,  which  if  a  little  worse  might  have  de- 
veloped into  epithelioma.  A  little  instruction  will  enable  any  patient 
to  hold  the  film  himself  and  so  protect  the  operator  from  the  danger  of 
frequent  exposures. 

Little  film  carriers  (Figs.  597,  598,  and  599)  have  been  devised  by  the 
author  for  holding  the  film  in  this  position  by  the  patient  simply  closing 
his  mouth  upon  them.  One  of  these  consists  of  a  thin  aluminum  case 


Fig.  ,507. — Touspy's  vertical  film  carrier. 

which,  when  closed,  is  nearly  water-proof  and  entirely  light-proof. 
It  takes  two  films  about  1X1,;  inch.es  in  si/e,  and  without  any  paper 
or  other  wrapping.  These  must  be  put  in  the  film-carrier  in  the  dark, 
of  course.  There  is  a  sort  of  flange  soldered  to  this  which  the  patient 
holds  between  his  teeth,  while  the  part  containing  the  films  is  thereby 
held  in  position.  These  vary  somewhat  in  form,  according  to  whether 
they  are  for  the  upper  or  lower  jaw,  and  as  to  whether  they  are  for  front 
or  back  teeth.  To  prevent  any  possibility  of  a  patient  swallowing  such 
an  instrument  a  short  handle  is  provided'.  This  also  facilitates  placing 
11  in  proper  position.  Anything  which  enables  the  operator  to  dispense 
with  holding  the  film  in  position  by  his  bare  fingers,  unprotected  by  a 
pair  of  .r-ray  proof  gloves,  or  which  will  allow  him  to  stand  ent  irely  away 
from  the  patient,  is  extremely  desirable. 

Leach's  film  carriers  are  very  convenient  for  all  the  lower  teeth. 

A  method  which  has  not  been  practiced  very  much,  but  which  is  an 
excellent  one  for  the  upper  jaw.  is  to  take  a  wax  impression  of  the  upper 
jaw  just  as  for  making  a  plate.  Put  the  film  in  very  thin  wrappings 
so  as  to  be  quite  flexible  in  the  proper  position  upon  this  wax  impres- 


sion   ami   replace   it    in   the   mouth.     This   is   perfectly   retained   if  the 
patient   closes  the  mouth  gently. 


Fiji.  iV.tV —  I.rarhV  film  carriers. 

It  is  rather  desirable  that  the  films  should  not  be  bent  or  curved. 
Distortion  of  the  image  will  he  apt  to  occur  and  this  might  occasion 
an  error  in  diagnosis. 


dult-  whom  the  author  ha-  examined  !>v  the  .r-ra\ 


in    position   with    their  own   finger 


THK    .r-KAY  (,)2!) 

They  must  bo  cautioned  against  involuntary  movements,  which  would 
somewhat  blur  the  image. 

Conditions  Shown  by  the  Radiograph. — The  radiograph  shows  all  the 
conditions  mentioned  as  shown  by  the  Huoroscope  and  shows  t  hem  bet  ter. 
In  addition,  it  shows  the  condition  of  the  bone  around  the  root  of  [the 
tooth;  rarefaction  caused  by  ulceration,  absorption  of  the  alveolus  from 
Rills'  disease  or  pyorrhea  alveolaris,  necrosis  and  sinus,  fracture, 
neoplasm;  also  changes  in  the  tooth  itself,  absorption  of  the  root,  peri- 
cementitis,  pulp-stones;  and  also  the  condition  of  the  antrum  of  High- 
more. 

Focal  Infection  of  the  Teeth. — "A  focal  infection  is  a  localized  area 
of  tissue  filled  with  pathogenic  micro-organisms,  where,  on  account  of 
physical  reasons,  natural  drainage  is  impossible."  '  The  author  had  made 
thousands  of  radiographs  of  the  teeth  in  cases  of  infection  which  gave 
local  signs  before  it  became  known  that  dental  infection  might  exist:  for 
years  unknown  to  the  patient  and  the  dentist.  All  this  time  the  focus 
of  infection  is  poisoning  the  system  and  is  usually  producing  symptoms 
more1  or  less  intermittently.  Very  commonly  the  dental  infection  is  a 
blind  abscess  which  shows  distinctly  enough  in  the  radiograph,  but  may 
not  be  discovered  by  an  ordinary  dental  examination.  Those  that  cause 
systemic  infection  are  not  usually  accompanied  by  pain  and  swelling, 
though  there  is  often  a  history  of  the  temporary  existence  of  such  symp- 
toms a  long  time  previously.  In  fact,  a  tooth  which  has  in  this  way 
presented  evidence  of  acute  infection  should  be  regarded  with  suspicion 
ever  afterward.  The  nerve  may  have  died  at  that  time  and  not  have 
been  removed,  and  the  dentist  now  notes  the  ordinary  evidences  of  a 
non-vital  tooth:  change  in  color  and  in  translucency,  insensibility  to  heat 
and  cold  and  electricity.  And  if  there  is  infection,  even  chronic  and 
painless,  the  dentist  will  often  detect  sensitiveness  on  percussion.  The 
.r-ray  often  settles  the  question  at  a  glance  by  showing  an  abscess  cavity 
or  area  of  decalcification  at  the  apex  of  the  root.  There  are  other  cases 
of  acute  infection  or  of  simply  death  of  the  nerve  which  have  been  treated 
by  removal  of  the  pulp  and  filling  the  pulp  chamber  and  root  canals.  And 
if  one  of  these  subsequently  becomes  infected,  the  .r-ray  may  be  the  only 
positive  means,  except  removing  the  root-filling  or  extracting  the  tooth, 
to  determine,  whether  this  dead  and  root-filled  tooth  is  infected  or  not. 
Such  teeth  often  form  the  anchorage  for  crown  or  bridge  work.  Pyor- 
rheal  pockets  are  as  evident  to  the  dentist's  ordinary  instruments  as  in 
the  radiograph. 

Symptoms  and  Lesions  Due  to  Long-standing  Dental  Infection. — The 
first  symptoms  are  very  apt  to  be  neuralgia,  neuritis,  rheumatism,  or 
indigestion.  Recurring  or  persistent  attacks  of  these  troubles  suggest 
the  necessity  for  an  .r-ray  examination  of  the  teeth.  In  cases  where 
the  focus  of  infection  is  not  discovered  and  cured  until  a  later  stage, 
lesions  are  produced  in  the  endocardium  and  arteries  with  all  their  possible 
serious  or  fatal  sequelae,  in  the  eye,  in  the  stomach,  and  duodenum, 
where  probably  dental  infection  is  the  usual  cause  of  ulcer  and  cancer, 
in  the  joints,  and  elsewhere.  It  has  been  found  that  in  the  Minnesota 
State  General  Hospital  12  per  cent,  of  the  patients  were  there  because 
of  disease  caused  by  dental  infection.  The  number  and  variety  of  the 
diseases,  including  many  cases  of  insanity  arising  from  this  cause,  makes 

1  \V.   D.  Tracv,  Jour,  of  Dental    Research,  vol.   i,   Xo.  3.  September,   1919,  p. 

i 

I XXXI. 


930  MKDICAL    ELK(  THH'iTY    AND    RONTCK.N     KAYS 

it  a  matter  of  the  utmost  importance  to  discover  and  cure  dental  in- 
fection while  its  secondary  effects  are  trivial  and  curable.  Infected 
thrombi  arising  from  the  heart  valves  and  lodging  in  the  brain,  lungs, 
kidneys,  spleen,  or  other  vital  parts  are  the  immediate  cause  of  painful 
and  fatal  complications  in  some  cases  of  dental  infection. 

The  many  writings  of  Hosenow  and  his  wonderful  investigations 
have  shown  that  there  is  not  only  a  causative  but  also  a  selective  re- 
lation between  focal  infections  and  secondary  lesions.  Inoculation 
from  a  tooth  abscess  in  a  case  with  endocarditis  may  produce  endocardi- 
tis; and  from  another  case  with  gastric  ulcer  inoculations  from  a  tooth 
abscess  may  produce  ulcer  of  the  stomach.  Frank  Hillings  and  the 
present  author  have  made  many  important  observations  and  so  have  a 
h<  ist  of  ot  hers. 

The  author  makes  a  set  of  dental  radiographs  in  every  case  of  cancer, 
wherever  located,  and  has  always  found  dental  infect  ion  usually  more 
severe  than  in  cases  already  universally  recou'iii/ed  as  due  to  that  cause. 
The  fact  that  newborn  children  may  have  cancer  shows  that  dental 
infection  cannot  be  responsible  for  all  cases:  but  if  cancer  is  ordinarily 
due  to  a  germ  which  must  be  lodged  for  a  long  time  there  is  no  place 
in  the  body  more  suited  to  this  permanent  lodgment  than  a  blind 
denial  abscess.  And  it  is  the  author's  firm  belief  that  the  timely  dis- 
covery and  cure  of  all  these  abscesses  would  make  a  wonderful  difference 
in  the  number  of  cases  of  cancer. 

Si/tn  I/tout*  of  Dtiift/l  Infection  <n'(  ])(tn(/<r  Snjndl^.-  A  man  hobbling 
about  with  a  pain  in  his  knee  is  not  to  be  regarded  simply  as  a  sufferer 
1o  be  relieved,  but  also  as  one  having  probably  in  his  system  the  germs 
of  serious  01-  fatal  disease.  And  the  physician's  responsibility  in  the 
case  is  all  the  greater  when  we  consider  that  at  this  stage  not  only  can 
the  knee  be  cured,  but  the  more  serious  consequences  prevented  by  the 
discovery  and  cure  of  one  or  more  dental  abscesses.  And  all  the  more 
when  we  see  case  after  case  where  this  is  undertaken  too  late,  after  the 
occurrence  of  an  incurable  and  fatal  sequela.  The  discovery  and  cure1 
of  one  or  more  infected  teeth  may  save  others  from  becoming  infected. 
I'm  a  return  or  persistence  of  the  symptoms  demands  another  set  of 
denial  radiographs.  The  radiograph  i>  the  only  sure  way  of  telling 
whether  r>n  instrument  reaches  just  to  the  apical  fotamen.  and  il  is  the 
cii.- torn  of  many  dentists  to  employ  this  guide  in  their  root  fillings. 

1,'iiil/iii/i'ti j>hi/  nf  tin;  I.ninr  T<(tli.-  For  a  radiograph  of  the  lower 
teeth  the  film  is  held  inside  t  he  mouth  as  nearly  parallel  as  possible  to  the 
lont:  axis  of  the  teeth  and  with  its  lower  edge  as  low  as  possible.  The 
patient  should  ffice  in  such  a  direction  that  the  .r-ray  will  shine1  between 
the  teeth  which  are  of  principal  interest,  so  that  llieir  shadows  shall  not 
overlap;  and  the  head  should  be  tipped  slightly  away  from  the  .r-ray 
1 1 1 be.  J -Acept  at  1  lie  side-  of  the  face  t  he  degree  of  curvature  of  the  jaw 
prevents  a  single  pid  ure  from  showing  more  than  three  or  four  teeth  well. 

THCHNIC  FOR  DENTAL  RADIOGRAPHY 

1 .  For  Expert  Rontgenologists  with  Every  Safety  Device. 

'J.  For  the  Dentist. 

I.  Technic  for  the  Rontgenologist.  The  best  pictures  of  the  teeth 
are  obtained  upon  the  >low  Kastman  dental  films  winch  are  the  same 
.1-  Huck  Slow  l)ental  Film-,  with  an  ant  icat  hode-skin  distance  of  13 
.  \\nli  an  exposure  of  five  seconds  except  for  the  upper  molars, 


THE   X-RAY 


931 


where  it  is  eight  seconds.  The  current  factors  are  4-inch  spark  equiv- 
alent and  30  milliamperes.  A  protective  x-ray-proof  cylinder  3  inches 
in  diameter  lias  its  insulated  rim  13  inches  from  the  anticathodo  and  can 
be  pressed  lightly  against  the  face  for  steadiness  and  accuracy.  A  l^-inch 
diaphragm  opening  is  at  about  .")  inches  from  the  anticathode.  The  bull) 
is  enclosed  in  a  lead  glass  bowl  and  at  a  distant  of  about  5  inches  from 
the  anticathode  is  a  filter  of  aluminum  1  millimeter  thick,  to  arrest 
all  ultraviolet  rays  and  the  softest  x-rays.  The  Radiator  Coolidge 
tube  is  the  .r-ray  tube  best  adapted  to  making  a  series  of  radiographs 
with  this  technic. 

The  most  convenient  position  for  the  upper  teeth  is  with  the  patient 
sitting  upright  in  a  chair  provided  with  a  head  rest,  with  the  head  erect 


and  the  occlusal  surfaces  of  the  upper  teeth  in  a  horizontal  plane.  The 
mouth  is  opened  by  dropping  the  lower  jaw  without  moving  the  head. 
The  most  convenient  position  for  the  lower  teeth  is  with  the  patient- 
sitting  upright,  the  lower  part  of  the  body  very  well  back  in  the  chair, 
the  chest  drawn  in  and  the  head  tipped  back  to  the  full  natural  extent 
and  supported  there  by  a  head  rest.  The  chin  is  to  be  up  in  the  air. 
The  film  measures  1  ]  x  1  [;-  inches  for  the  entire  series  now  to  be  des- 
cribed. The  direction  of  the  long  axis  of  the  film  is  horizontal  or  ver- 
tical for  different  regions.  For  the  upper  incisors,  film  vertical,  ex- 
tending slightly  below  the  edge  of  the  teeth,  and  pressed  by  the  thumb 
so  as  to  curve1  laterally  to  fit  the  arch  of  the  teeth,  but  not  curved  ver- 


tically.  At  it-  upper  end  it  re-t-  auain-t  the  roof  of  the  UK. nth,  and  near 
it-  lower  end  auain-t  the  teeth,  but  it  is  not  bent  so  as  to  follow  the 
curve  in  the  median  plane  between  these  two  point.-.  The  opening  in 
the  protective  cylinder  i-  a  uood  ^uide  to  the  proper  po.-ition  of  the  tube. 
t~-ually  the  plane  of  thi-  openin<r  should  he  parallel  with  the  front  of 
the  nose  and  the  upper  edue  of  the  opening  may  re.-t  lightly  close  to  the 
root  of  the  nose.  (  )f  cour-e  the  tul)e  is  to  be  exactly  in  the  median  line 
except  in  cases  of  a-ymmetry  of  the  face.  The  ./-ray  tube  is  about 
4")  decree-  above  a  horizontal  plane. 

F.tr  the  upper  cuspid,  bicuspid.-,  and  fir.-t  molar  the  urea  test  length 
of  the  film  i-  hori/ontal.   it-  upper  front   cornel'  is  bent    back   to  allow 


th<-  film  to  no  well  forward:  the  picture  u-ually  throw-  additional  li»'ht 
upon    the   condition   ot    the   lateral   and    -onietime-   even   of   the   central 
The  lower  edti'e  of  the  film  i-  parallel  to  and  very  slightly  be- 
low   the    occlu-al    .-urface-    of     the    teeth.      The    upper  (•(!»•(•  (,f   the   film 
i-  aiiam-t    the  roof   nf   the  mouth  about  ,-it   the  median   line.      This  film. 
like  the  fir-t.  i-  cur\'ed  -omewhat  laterally  by  the  pres.-ure  of  the  thumb 
Jd     it    in  place;  but   it   -hoiild  not   be  curved  to  any  »reat  exien* 
vertji-ally.      The   (<lt;-c   of   the   opening   in    the   cylindei-   should    rest    at 
;  , '  •  •   part  of  t  he  eyebrow.      The  direct  ion  of  t  lie  ray-  i.-  from  a  point 

I'---  than    l.'i  dearer-  in  front  of  a  t  ran-\'er-e  vert  ical  plane  and  le.-.-  t  han 
1")  ileirpei  -  below  t  he  Vertical. 

I  <ir  the   upper  molar-   the   film   is   hori/ontal.   it-   po-terior  superior 


THE    J-HAY 


033 


corner  is  bent  hack  to  avoid  pressure  on  the  soft  palate  and  so  permit 
the  film  to  go  well  back.  The  lower  edge  is  parallel  to  and  slightly  be- 
low the  occlusal  surfaces  of  the  teeth,  the  upper  edge  is  against  the  roof 
of  the  mouth  near  the  median  line.  The  film  is  somewhat  curved 
laterally,  but  not  much  vertically,  by  the  thumb  that  holds  it.  The 
edge  of  the  protective  cylinder  rests  against  the  temple  in  a  line  with 
the  malar  bone.  The  tube  is  exactly  4~>  degrees  from  the  perpendicular 
and  slightly  forward  of  a  transverse  vertical  plane  passing  through  the 
malar  bone.  The  reason  for  using  a  longer  exposure  here  is  because  of 
the  density  of  the  bony  parts.  The  author  has  used  almost  exclusively 
Buck's  slow  dental  film  which  is  the  same  as  the  Kastman  positive  cine- 


matograph film  and  as  the  Kastman  slow  dental  .r-ray  film.  But  for 
this  particular  region  the  extra  rapid  film  with  a  time  exposure  only 
one-fifth  or  less  than  with  the  regular  film,  i-  being  given  a  trial.  The 
author  believes  thai  for  dental  radiography  the  exposure  should  be  so 
timed  that  the  sensitized  film  may  be  developed  all  the  way  as  evidenced 
by  the  image  showing  clearly  on  the  back  before  it  becomes  TOO  dark  in 
front.  This  require-  two  or  three  minutes'  development.  A  good  way 
to  test  this  matter  is  by  givinsi  one  of  these  extra  rapid  films  a  direct 
exposure  at/23  inches.  4-inch  spark.  30  ma.,  part  one  second  and  part 
TWO  seconds.  As  this  is  developed  the  front  becomes  entirely  black  be- 
fore the  back  shows  more  than  a  general  slight  discoloration  within 
any  division.  Another  film  exposed  for  one-quarter  and  one-half  second 


934 


MKD1CAL    KLKCTHH'ITY    AND    HONTGKN    HAYS 


develops  more  slowly,  with  a  clear  division  of  the  darker  and  lighter 
portion-,  both  front  and  back.  This  is  the  way  that  a  slow  dental  film 
should  behave  in  the  developer  and  the  exposure  should  be  timed 
accordingly.  It  may,  however,  prove  impracticable  with  the  rapid 
dental  films. 

For  all  the  upper  teeth  the  patient's  thumb  is  the  most  satis- 
factory film  holder,  just  pressing  the  film  into  place,  not  holding  it  be- 
tween thumb  and  finuvr.  For  the  upper  incisors  any  kind  of  a  film 
packet  will  do,  but  if  it  is  not  lamely  made  up  of  metal,  care  must  be 
taken  not  to  curve  it  vertically.  For  all  the  other  upper  pictures  the 
desirability  of  bending  either  the  upper  front  or  the  upper  back  corner 


mal-.r-  :'   e-.-enti:d  to  u~e  ,-i   packet    made  up  lar^elv  of  pliable  metal  re- 
im    any   -hape   mt.p   which    it    i-    bent.      Racket-   made   up  entirely 
of  paraffin  paper  are  much  lr--  de-irabie  here. 

1  or  the  lower  inci-Mir-  the  film  i-  vertical,  curved  laterally,  so  that 
it-  ed'je-  t;t  in-ide  the  fir-t  bicu-pid-  and  I  he  convexity  i-  ferward. 
Tt;  lowi'i1  edu.f  pre--e-  down  the  frcnum  of  i  he  tongue  and  should 
riot  extend  hori/ontally  back  under  the  toiitrue.  luit  the  film  should  be 
a-  iieariy  vert:i-;i]  a-  po--ib]e.  It  dor-  imt  touch  the  lower  incisors 
at  all.  :  M  the  handle  of  I, each'-  film  carrier  -hould  pre--  back  against 
the  u]ip-  :  !i'  i-or-.  T«i  siet  the  film  far  enouuh  clown  to  show  the  jaw 
below  t  !M-  a  pier-  of  t  he  tert  h  require-  t  he  i  n  t  el  i  i-c 'tit  co-operation  of  the 


THE    X-RAY 


935 


patient.  He  must  relax  the  muscles  of  the  floor  of  the  mouth  so  as  to 
bring  the  teeth  up  in  front  of  the  film.  A  partial  attempt  to  bite  the 
film  produce's  the;  right  effect,  bringing  the  teeth  up  and  enabling  one 
to  press  the  film  down.  The  author  has  no  difficulty  in  making  radio- 
graphs of  his  own  lower  incisors  showing  the  lower  edge  of  the  jaw. 
The  lower  edge  of  the  opening  of  the  protective  cylinder  is  close  to  or 
just  below  the  chin.  The  direction  of  the  .r-ray  is  from  about  20  degrees 
below  the  plane  of  the  occlusal  surfaces  of  the  lower  teeth.  Care  must 
be  taken  that  the  wires  or  the  terminals  of  the  tube  are  not  near  enough 
to  any  part  of  the  patient  to  give  a  spark.  The  exposure  should  be 
only  four  seconds  and  the  development  should  be  with  special  reference 


to  securing  detail  below  the  apices  of  t he  foots.  If  there  is  a  metal  rim, 
as  with  Buck's  films,  this  serves  as  a  guide.  The  lower  part  of  the 
film  should  show  decided  contrast  with  the  pure  white  of  the  margin. 
But  we  especially  do  not  want  to  blot  out  details  of  the  alveolar  proc- 
ess between  the  roots  of  the  lower  incisors.  The  guides  are  sufficient 
darkening  of  the  lower  part  of  the  picture,  dark  or  black  lines  showing 
the  root  canals,  not  losing  the  imau'e  of  the  cutting  edge  of  the  lower 
incisors.  \\  js  much  better  to  develop  a  little  more  rather  than  not 
enough.  I'eduption  will  correct  the  former  after  the  film  is  fixed  and 
can  be  looked  at  by  the  ordinary  light. 

For  the  lower  cuspids  and  bicuspids  the  film  is  vertical,  the  lower 
front  corner  is  bent  back  to  allow  the  film  to  come  well  forward.     The 


l).-)<)  MKlUt    \I.    KI.Kt  TKKITY    AND    KnXTGKN     HAYS 

film  i-  close  In  the  teeth  and  MS  nearly  vertical  as  pos>ible.  but  the  lower 
edLie  mu-t  lie  a  li'tle  internal  .-o  as  not  to  ])ro<luce  pressure  upon  a 
-en-itive  bony  ledue  on  the  inner  surface  of  the  jaw.  The  handle  of 
Leach'<  film  holder  i-  to  be  parallel  with  the  l.iiiu  axis  ,,('  the  lower  fir.-t 
bicu-pid.  The  lower  ediie  of  the  opening  in  the  proteetive  cylinder  i- 
ju-t  below  t  he  li  iwer  ediie  of  t  he  li  >wer  jaw  and  the  direction  of  the  .r-ray 
i-  from  about  \~)  decree-  below  the  plane  of  the  ocdusal  surfaces  of  the 
lower  teeth  and  from  about  70  decrees  in  front  of  a  coronal  or  lateral 
vertical  plane  pa  — hm  through  the  iirM  bicu-pid  teeth.  The  patient 
mu-t  relax  and  partly  bite  and  partly  press  the  film  >o  that  the  crowns 
of  the  lower  teeth  are  close  to  its  upper  edsre. 

l-'oi-  the  lower  molar-  the  loiiii  axis  of  the  film  is  horizontal,  it  must 
I'e  in-ide  t  he  upper  a-  well  as  the  lower  teet  h.  or  it  will  be  impossible  to 


mlii  LTUI  liy  of   i),.'  low.  r  mo 


•  i'    far  enough   back   to  include  the  root   of  the  lower  third  molar 

"r""'     extend-     hori/ontallv     backward.      Leach'-     film     holder 

1     '     ;"    -'•<•    .;|i-i    where    to    place    the    film.      The    lower    ed^e 

be    inclined    inward    -licihtlv    to   avoid    a    sen-hive    led  tie  of   bone. 

iu-t    include-    the   fir-t    molar.      The    upper  edue   is    JUM 

'Wli-    ot     the     lower    molar-.      The     patient     relaxes    and 

holdiny:   the   latter   to   make   sure   that    the   film   does 

1 'ci-M-ionally    \\ith   a    chiM   or   ner\'ous   patient    who 

•  •aniiot    co-operate    with    you    it    \\ill    be    impos-ible 

!l  e  1,-i-t   lower  molar  root   upon  a   film  held  inside 

case  an  external  pirt  ure  i-  made,  placing  M<r<"iin-l 

la'e  ;,!,  |-.a-tmati  dupl'tixed  film  \\ithoul  an  intensifying 


THK  ,r-\ 


screen.     The  head  is  inclined  a  little  to  that   side  and  the  x-ray  tube  is 
behind  the  other  shoulder  so  that  the  x-ray  comes  from  behind  and  below 


<i    transformer    fm-    dental    radiography.     (Campbell    Klro- 


the  an<rle  of  the  jaw  on  the  side  opposite  to  that  depicted.  The  anti- 
cathode  is  :2o  inches  from  the  film,  equivalent  spark  5  inches.  30  ma.,  ex- 
posure ten  seconds  for  a  lartre  person  (see  Exposure  Table,  pa  ire  890.) 


MKDICAL    KLKCTKICITY    AND    RONTGEN    HAYS 

Development  produces  an  image  on  both  sides  at  once  and  should  be 
continued  until  the  jaw  is  almost  but  not  (mite  lost,  and  shows  no 
transmitted  li^ht  until  after  fixing  in  the  hypo. 

Technic  Suitable  for  the  Dentist.—  There  is  manufactured  now  a 
cabinet  which  can  be  wheeled  about  the  floor  like  a  table  and  which  com- 
pri-es  a  transformer  for  the  delivery  of  high-tension  .r-ray  current  and 
another  transformer  for  applying  the  low-tension  current  for  the  fila- 
ment for  a  (  'oolidge  t  ube. 

Firmly  attached  to  the  cabinet  is  an  adjustable  tube  holder.  The 
new  dental  ('oolidge  tube  is  of  the  radiator  type  with  a  bulb  only  a 


I.    Tmiscy    film    clip,    sictuul    size.      li.    Kodak    film    flip    whose    hook   i 


ti-urd  :iii(!  suldercd   to  metal    .'.  inch    wide  and    ,',    inch    thick   for  Tousey's   clip.      (', 


I.'  •-  d''-iral>le  koilak  film  clip,  tin-  handle  hciiifj;  of  metal  only  ,;,  inch  wide  and  very  thii 


little  over  •>  indie-  in  diameter.  The  body  and  .-tern  of  the  anti- 
cathode  are  directed  away  from  the  surface  <:('  the  ])atient  instead  of 
benin  parallel  tu  the  jtlate  or  film  as  in  the  slandard  ('oolidge  tube. 
Tlit1  tube  i-  enclosed  in  a  close-fitting  lead  gla^s  shield  protecting  the 
operator  and  all  parts  of  the  patient  except  his  face.  The  generator  and 


with  the  slow  dental  films,  which  are  usually  preferable,  should 
be  about   four  seconds  for  all  but  the  upper  molars,  for  which  it  should 


!•"!;_'.  (10s. — TouseyV  clip  holding  a  film. 

be  -in, Mt  eiMit   seconds.     The  rapid  dental  films  require  about  one-third 
a-   long. 

/ ><    ilnfiiinj    Clips    /'«/•    l)tnlnl   /'V////X.      The   clip-    used   by   the   author 

are    ;i    mollification    of    Hio-e    -old    by    the    Ka-tman    Kodak    Company. 

•ttti  •   have  a  liook  which  i-  hardly  more  than  a  bent  wire.      A  hook 

i  if  ':    •    metal   ',   inch  broad  and   1   inch  thick  has  the  advantage  of  being 

more  ea -i I y  handled  a  nd  I  ving  more  securely  in  t  he  proper  position  over 

!•   of   the   developing    tray.      The   films   lie   flat    in   the  tray  and 

each    film    i-   held    in    it-   own   clip  during  development,  fixing,  washing, 

and   drying.      for   whole-ale  work   done   po--ibly    by   someone  who   has 

!i'<-   the  time  or  t  lie  skill  to  watch  the  development   of  each   film  and   to 


THE    X-RAY 


939 


vary  the  time  according  to  the  results  then1  are  multiple  clips.  These 
hold  ten  films  to  he  developed  ;i,t  once  in  the  same  length  of  time  re- 
quired for  one  film.  The  author  uses  individual  film  clips  exclusively, 
with  an  <S  x  10  inch  developing  tray.  A  film  is  put  in  a  clip,  rinsed 
in  water  to  moisten  the  surface  throughout  and  avoid  air-hells,  and 
placed  in  the  developer.  Another  film  and  possibly  several  follow  into 
the  developer  hefore  this  first  film  is  sufficiently  developed.  As  fast 
as  individual  films  attain  sufficient  density  they  are  taken  out  of  the 
developer,  rinsed  in  water,  and  placed  in  the  fixing  and  hardening 
solution,  from  which  they  go  into  running  water,  and  are  finally  hung 
up  to  dry.  If  the  water  is  not  cold  enough,  as  happens  in  New  York 
for  the  six  summer  months,  the  film  develops  a  cracked  or  mosaic  ap- 
pearance which  destroys  the  picture.  Ice-water  is  used  to  prevent  this 
defect,  and  six  complete  changes  of  water  at  intervals  of  a  few  minutes 
are  sufficient. 

Tra>i  Development  for  Dental  Fil/n*. —  Whether  one  film  or  two  do/en 
are  to  he  developed,  the  author  prefers  the  tray.  The  progress  of 
development  of  each  film  can  he  ohserved.  And  as  each  one  approaches 


Fiji.  00'.). — Uso  of  Tousev's    clips  for 


completion  it  may  he  taken  out  and  held  near  enough  to  the  safe  ruhy 
light  to  look  at  hoth  sides  carefully;  hut  do  not  attempt  to  test  it  hy 
transmitted  light. 

J/n!(///uj  the  Development  of  Denial  /-'/7///X. — First,  the  part  not  oh- 
structed  hy  the  teeth  or  hone  hecomes  dark,  then  the  outline  of  the 
light-colored  teeth  in  the  slightly  darkened  jaw.  Later  the  teeth  he- 
come  somewhat  darkened  with  metal  iillintrs  or  crowns  showing  pure 
white  and  the  root  canals  hlack;  and  the  whole  image1  showing  clearly  on 
the  hack  of  the  film.  Full  development  is  indicated  when  the  whole 
film  looks  hlack  at  a  distance  of  IS  inches  from  the  lamp,  hut  the  thin 
edges  of  the  crowns  of  the  teeth  are  still  clearly  visihle  within  (i 
inches  of  tin1  lamp.  A  change1  of  the  nature  of  a  dark  frost  or  veil 
over  the  imau'e-  of  the  teeth  indicate--  overdevelopment.  The  latter  is 
not  to  hi1  dreaded  hecause  it  is  easily  corrected  hy  reduction,  while 
underdevelopment  is  practically  fatal. 

induction  of  Overdeveloped  Tooth  /-'/7///.S-. — It  is  not  always  pos- 
sihle  to  judge  of  just  exactly  the  hest  density  hy  the  ruhy  light,  and 
in  heing  ahsolutely  sure  to  avoid  underdevelopment  some  films  will 


940  MKDICAI.    KI.F.t  TKICITY     AM)    KONTCKN     HAYS 

In1  found  too  dense  when  viewed  1  >y  ordinary  transmitted  liuht.  These, 
whether  they  have  Keen  dried  or  not.  are  easily  reduced  in  density. 
The  process  is  carried  out  l>y  ordinary  li<;ht  and  is  stopped  when  the 
him-  have  ju-t  the  proper  density.  After  soaking  in  water  the  film  is 
placed  in  the  reducing  solution: 


fiii-  sixty  >econds.  Then,  if  not  -uflicienl  ly  reduced,  the  film  is  placed 
in  t  he  red i : chin  >olut  ion  for  twenty  seconds,  t  hen  washed,  and  then  in  the 
hypo  for  sixty  -econd>.  The  twenty-second  reduction-  are  repeated  until 
reduction  i-  sufiicient.  Do  not  overdo  it.  Kvery  trace  of  the  pic- 
'ure  can  1-e  removed  in  this  way.  The  reducing  solution  does  not  have 
in  lie  fre-hlv  made.  It  can  be  used  until  it  ceases  to  act.  A  stock 
-oiution  of  eiuht  times  this  strength  can  lie  kept  on  hand  and  lasts  in- 
definitely. It  i-  very  poisonous,  (if  course  the  stock  solution  i< 
diluted  to  one-eighth  the  strength  with  water,  makintr  the  formula  for 
actual  use: 


Overexposure  and  full  development  may  result  in  a  film  so  dense 
as  to  tie  entirely  opaque,  which  when  reduced  idves  very  sharp  con- 
trast.  This  i-  far  better  than  an  overexposed  and  underdeveloped 
film  or  ;m  underexposed  and  overdeveloped  film  of  the  same  final 
den-ity.  It  is  not  -o  uood.  however,  as  a  film  which  has  been  correctly 
exposed  ;md  inven  normal  development. 

77"  I in/ii/i  S/niiriiii/  an  tin  ]><icl:.-  Dupliti/ed  films  without  an  in- 
ten-ifviim  screen  ha\'e  both  sides  about  e<nially  affected  by  the  x-ray. 
And  both  -urfaces  are  darkene<l  at  the  >ame  time  by  the  developer  to 
such  an  extent  that  one  can  only  jud.uv  of  the  effect  upon  the  deeper 
partiHes  of  -ilver  by  the  den-ity  of  the  !i!m  as  te>ted  by  transmitted 
iiu'lit.  And  if  you  lose  the  i  ma  ire  the  film  is  likely  to  be  entirely  too 
'i'-n-e.  The  projter  density  lies  >ome\\'here  between  the  first  distinct 
di-colorat  ion  of  th'-  part  to  be  depicted  and  the  entire  blackness  of  this 
part.  A  marinn  covered  by  opaque  metal  diirinji  the  exposure  fur- 
T;:-ii«--  :i  ii-eful  iruide  to  development  because  it  doe-  not  become  dis- 
lored,  mill  one  -ooii  become-  accustomeil  to  juduc  of  the  most  de- 
-irable  eoiili'a-1  betucen  tin-  white  area  and  the  important  part  of  the 
film. 

The  dupliti/ed  dental  film-  are  the  -.-ime  as  other  dupliti/cd  film-. 
Tin-;,  iri  open  to  the  objection  that  on  account  of  their  extra  thick- 
lie—  they  ;tre  u-ually  oiil\'  one  in  a  packet,  while  most  dental  packets 
M  two  -ini;le-coated  film.-.  A-  a  rule,  -hid it  underexposure  and 
-linhi  lopment  re-nit  in  a  -oft  film  lacking  conti'ast  of  a  nature 

in  L;'  '  be  de-irable  in  a  portrait  photou'ra|)h  and  not  so  desirable 
iii  -hde  copy  ot  black  and  white  dra\\inu-.  A  developer 

containini;  im-tol  or  it-  ecpiivaleni  i-  u-<-tul  for  produeinji  an  effect 


THK    .T-KAY 


all  the1  way  threiugh  the1  film  as  shown  by  tl 
plate  e>r  of  a  single-coated  film. 

The  Author'*  (Ha**  Mount  for  Dental  Fil 
are  faste'nerl  be'twce'ii  twe>  she'Cts  of 
picture-frame  glass,  pivseTving  them 
from   any   injury   and   giving  them 
pe'rfer-t  transparency.     Te>n  1-J   x   l£ 
inch    films   fe)rm   the  usual  set  and 
the1  pieces  e>f  glass  measure   H  x  10 
ine-hes.       Double-coated      adhesive 
plaster  (Janus  plaster,  sold  for  wig- 
making  and  e>ther  mechanie-al  pur-          ] 
pe>seis)  is  cut  into  strips  {-ine-h  wide1. 
A  piee-e  of  glass  laid  upem  the1  table1 
has  a  complete1  l)e>rdeir  of  plaster  ] 
inch  wiele1  enclosing  a  central  ami 
in    which   are   fitted    the1    ten    films 
with  a  elese-riptive  label  at  erne1  e'nel. 
Holding   the   cover-glass   close   and 
pressing  lightly  upon  the  films  the1 
latter  may  be  accurately  petsitienierl 
with   a    paper    cutter   or  a  hat-pin.       -: 
\\  he'n  the  cover-glass  is  once1  presserl       ~: 
elown  it  is  held  permanently  by  the1       ^  ; 
e'ontae-t  with  the1  elouble  coatee!  plas- 
te'r.     A  strip  of  white  gummed  tape       ^\ 
forms  a  se>rt  of  passe-partout  bind- 
ing all  are)iinel  the  edge  and  forms  a       £ . 
border    upon    which    certain    brief 
notes  may  be  written. 

Celluloid  Film  Mounts. — These  I; 
are  made  either  entirely  erf  gremnel  2  ; 
evlluloid,  translucent  but  nett  trans- 
])areint,  or  e>f  paper  etr  cardboard 
with  gremnel  e'elluloiel  openings. 
They  hold  the  films  in  sue-h  a  way 
that  they  e-an  be1  viewer!  as  a  trans- 
parency if  helel  up  te>  a  strong  light. 
The\v  do  m>t  give  as  clear  definition 
as  the  glass  mounts,  but  are  invalu- 
able1 when  the  films  must  be  se>nt  by 
mail. 

Interpretation  of  Dental  Railio- 
yraph*.- - -Twe>  methods  e>f  stuely  are1 
available1:  first,  examination  of  the1 
film  by  transmitter!  light;  ami  ser--  ; 
ond,  examination  of  the  print  made1 
from  the  film. 

The    Film. — This    pivse^nts    pic- 
ture's  (Figs.  Gll-()14)   in  which  the 
elensest   parts,  such  as  metallic  fill- 
ings anel  e-rown  and   bridge  work,  are1  very 
totally  opaque  te)  the  x-ray  prenlue'es  an  almo 


le  image  on  the-  hack  e>f  a 
m*.~  The1  developed  films 


light.     An  object  almost 
st  complete1!}-  transparent 


94l> 


MKIHCAL    KI.KC  TKUTIY    AND    RONTGEN    RAYS 


image  on  the  film.  The  part  of  the  film  which  has  been  directly  exposed 
to  the  .r-ray  is  black  and  almost  opaque.  The  part  which  represents  the 
lip  is  slightly  less  opaque,  and  can  almost  always  be  seen  in  the  film. 
1  he  image  ot  the  teeth  is  much  more  transparent,  and  appears  nearly 


while  by  transmitted  light.      The  root-canal  and   pulp-chamber  appear 
somewhat  darker  than  the  body  of  the  \<  olh. 

The  apical  foramen  may  not   be  noticable  in  a   normal  adult  tooth. 
It    becomes    clearly    visible   if   a    root-filling   or   any    instrument    passes 


'  ion     |-'i<r.  o|('>.  and  especially  !•"]-.  lilfi'. 

film  -hould.  if  practicable,  be  expired  with  its  sensiti/ed  surface 

lube,  and  i-  to  be  looked  at   by  transmitted  light,  hold- 

•  'ween  the  eye  and  an  open  window,  or  holding  it   over  the 

u]    M    negative  examining   box.      A    magnifying  glass  or 

"n:"  i;  MJ   i!  be  u-ed  with  advantage  in   the  latter  case.      The 

film-Hiita         •    h'j   h'M  away  tVom  the  observer,  the  picture  appears  in 


THE    X-KAY 


943 


its  proper  relations.  This  is  as  if  the  observer  were  inside  the  mouth, 
and  should  view  by  light  transmitted  through  the  jaw  the  teeth  lying 
between  his  eye  and  the  .r-ray  tube.  The  latter  simile  applies  to  the 
radiographs  made  upon  films  held  inside  the  mouth.  A  film  or  plate 
held  outside  the  face  should  IK;  exposed  with  its  film  surface  toward 
the  x-ray  tube  during  the  exposure,  and  should  be  examined  with  its  film- 
surface  toward  the  source  of  light  and  away  from  the  observer  in  order 
to  see  objects  in  their  true  relation.  This  is  as  if  the  patient's  head 
were,  transparent  and  were  placed  between  the  observer  and  a  light. 

The  last  case  corresponds  also  to  the  image  seen  in  the  ordinary 
box  (luoroscopc  or  in  the  author's  magnifying  fluoroscope. 

The  Print. — The  sensiti/ed  surface  of  the  film  or  plate  is  placed  next 
to  that  of  the  paper,  as  is  always  done  in  making  a  photographic  print, 
unless  there  is  some  special  centra-indication.  This  makes  the  print 
correspond  exactly  to  the  film  when  the  latter  is  viewed  in  the  proper 
way,  i.  c.,  with  the  sensitized  surface  away  from  the  observer. 

A  paper  should  be  selected  which  will  give;  good  contrast,  and  so 


Fiji,    lil.").  —Apical    foramina    flaring    in    a 


— -Apical    foramen    nanny:    in    an 


make  pictures  which  will  reproduce  fairly  well  in  a  photo-engraving 

if  the  picture  is  To  be  used  in  illustrating  an  article.  At  the  same  time, 
the  surface  should  be  a  smooth  one.  so  that  the  finer  details  will  not  be 
obscured  by  the  grain  of  the  paper. 

'•'({lossy  velox,''  a  paper  made  by  the  Kastman  Kodak  Company, 
has  the  proper  surface,  and  has  tones  varying  from  white  through 
var.ous  shades  of  gray  to  black.  Tt  gives  sufficient  detail,  and  is  easy 
to  use  because  it  requires  only  a  few  seconds'  exposure  to  an  ordinary 
electric  or  gaslight.  It  may  be  developed  by  the  meTolhydrochinon 
.solution  that  is  used  for  the  films. 

Prints  made  upon  solio  paper  require  many  minutes'  exposure  to 
sunlight,  as  these  films  are  much  denser  than  those  produced  by  ordinary 
portrait  or  landscape  photography.  These  prints,  however,  give  some- 
what greater  detail  than  the  velox  paper.  They  have  a  brownish-red 
color  and  reproduce  very  well  in  a  photo-engraving.  Thev  are  less  apt 
to  be  permanent  than  the  velox  prints  unless  the  toning  and  fixing  are 
very  thoroughly  done.  Ordinary  portrait  photographs,  which  gradually 


'.HI 


fade  nut .  are  example-  of  1  he  lack  of  permanence  found  in  papers  of  this 
class. 

The  print  present  >  an  exact  reversal  of  the  lights  and  shadows 
of  the  tilm.  The  liackgroimd  should  lie  a  pure  while,  and  metallic 
filling  and  crown  and  l>ridge  work  jet  Mack.  The  teeth  are  next  in 
darkness,  and  structure  of  the  bone  is  gray.  The  normal  antrum  ap- 
pears almost  white,  and  so  do  large  cyts  which  have  been  emptied  of 
liquid  contents.  1'us  in  I  he  antrum  gives  a  dark  appearance  at  the 
most  dependent  poll  ion.  An  alveolar  abscess  i<  seen  as  a  light  area 
arouin  I  t  lie  apex  oi  1  he  root . 

The  print  is  the  exact  duplicate  of  the  tluoroscopic  image.  The 
alveolar  process  and  the  jaw  show  less  transparency  in  the  film  than  thi- 


I-'L'.  ill  ,  .  — Absees-  at  apex  of  central 
and  lateral  incisor-,  with  fir-tula  in  roof  ot' 
mouth. 


]-"j Lr  (•>•_'{).  —  Incipient  alveolar  abscess 
ot  loucr  tirst  f)icu-.pid  and  eroMon  of  apex. 
Second  bicii-pid  root  lias  been  >qiiareiy 
;ini]>utate<l  by  a  similar  proee->. 


!eet  h.  ;i  nd  the  details  ol  st  ruct  lire  are  well  shown  in  a  good  film.      Darker 
portions  in  the  film  or  lighter  portion^  in  the  prim  indicate  less  density 
lie  1  M  me. 

/.«  .nt,.:  1,'t  n  ah /I  In/  tlir  .r-l\tii/.  An  (ili't'olur  uhxcrx*  shows  in  its  very 
H'ipieticy  a-  a  darker  area  (if  film  for  lighter  in  the  print)  surrounding 
v  apex  of  the  root  i  Ki<r-.  017  h"2()). 

I  \vo  radiographs,  mad'1  from  different  elevations'   !' !''ig.  o'21),  enahh- 
te  thi    alisress  cavit\'  a-  extendinu   in  a   line  with  the  axi^  of 
'he  tooth  or  towird  or  away  from  the  surface. 

r'ort-rh.  a.  ,{.  (',<•],.  ,|.    Hoent  t£en-t  ralilen,    I'.M'J.  p.  JOT. 


The  mental  foramen  shows  in  ;i  radiograph  of  tin1  lower  bicuspid 
region  and  is  frequently  mistaken  even  l>y  the  dentist  for  an  abscess 
of  one  of  the  lower  bicuspids.  There  is  danger  that  a  healthy  and  vital 
lower  second  bicuspid  may  be  drilled  into,  the  nerve  destroyed,  and  by 
an  unfortunate  chance  the  root  canal  infected,  and  in  extreme  cases 
the  tooth  be  lost.  No  matter  how  much  like  an  abscess  it  may  look, 
it  is  always  best  to  compare  it  with  a  radiograph  of  the  same  region  on 
the  opposite1  side.  If  the  right  and  left  bicuspid  regions  show  the  same 


appearance  it  is  doubtless  due  to  the  normal  presence  of  the  mental 
foramen. 

The  x-ray  is  useful  in  locating  a  tooth  or  the  particular  root  which  is 
affected  by  alveolar  abscess;  also  in  discovering  the  cause  of  irritation 
in  cast's  of  unerupted  supernumerary  teeth  and  other  unsuspected  ab- 
normalities. 

A  blurred  and  lumpy  appearance  of  the  root  suggests  the  possibility 
that  the  film  may  have  moved  during  the  exposure.  Another  picture 
should  be  made,  using  extra  precautions  against  this.  A  perfectly  clear 
tin 


1)40 


MKDICAL    KI.KCTHICITV    AND    UONT(iKN    HAYS 


picture  will  usually  show  whether  some  lesion  has  given  the  lumpy  ap- 
pearance to  the  root  in  the  blurred  picture. 

A  case  of  injhnnntntion  and  of  loosening  of  the  tooth  from  an  im- 
perfectly fitting  crown  showed  in  one  of  Hhein's1  radiographs  an  en- 
tirelv  healthv  condition  of  the  alveolar  socket. 


A  ci/*t  or  ({hxccxx  cavity  in  the  bone  shows  as  a  dark  area  of  film,  or 
a  light  area  in  the  print,  with  a  clearly  defined  outline  ( Fig.  (122). 

\i  (•/•O.-.-/N  shows  as  a  somewhat  darker  area  than  the  portion  of  film, 
or  lighter  area  than  the  portion  of  the  print,  representing  normal  bone. 


Tin-  necrotif  an -a   is  more  transparent   to  the  x-ray,  which,  therefore, 

darken.-    the   tilm   more  than   el.-ewhere.      (  )f  course,  it   is  lighter  in  the 

int.     Thi-  difference  is  only  slight,  however,  and  the  picture  requires 

irHation    by   one   familiar   with    this   department    of  radiography. 

'  ire  of  dead  bone  does  not  appear  markedly  different  from  that. 

«•!  bone  in  the  radiograph,  and  there  is  often  no  sharply  defined 

outline  to  the  area  ^I-'itr-.  02.'$  02S). 

\   film  ol   the  upper  jaw.  made  upon  a  horizontal  plane  (Fig.  029), 
•i'kmti-  which  correspond  to  the  nasal  fossa'  and  the  antra. 

the  author's  radiographs   (Fig.  OM(b   is  of  a   case  of  necrosis 
and     -tul;i,  in  which  a   liold  probe  enters  a   cavity  in  an  upper  central 
1  Jour.  AIIHT.  M.'d.  Assnr.,  .luly  L'Y  I'.tOii. 


THE    X-RAY 


947 


Fifi-  *>-';>• — Necrosis  about  upper 
lateral  incisor.  This  tooth  had  been  ex- 
tracted, the  alveolus  curetted,  and  the 
tooth  reimplaiited  with  a  porcelain  cr<i\\n. 
The  tooth  acted  as  an  irritant  foreign 
bodv. 


Fit:.  f»2(i.-  Necro-is  of  jaw  with  fi<tula 
below  chin  open  for  six  years,  left  lower 
central  incixir  extracted.  Sinus  curetted. 
Cure  in  fourteen  days.  (My  own  patient 
at  St.  Bartholomew's  clinic.) 


riir.  ()27.— Extonsivo  area  of  necro-i.-  fn.-n 


I-'iic.  <',_>s. ^Necrosis  about  rout  of  up- 
per central  incisor.  The  large  apical 
foramina  and  the  unerupted  teeth  -how 
t  hat  the  pat  lent  j-  ;1  <  hiM. 


Fig.  (il'it.—  Markings  Fit.'.  ('.:>().  • — Probe    enters  Fig.  (JH1.       Fracture       of 

due   to   the    no-triK  not        ca\'ity      in      central      inci-or,        lower    jaw.     I.etween     the     two 
to  UfCT'Kis.  pas-es  throiiirh   entire   lenmh        bicusjiid  roots, 

of     root,      and      eiiierire-      in 
nostril. 


<)4S 


MF.IMCAI.   KI.F.I TKK  ITY   AND   KOXTCKX   HAYS 


incisor,  through  the  rout-canal  ami  the  hone,  to  emerge  from  the  nostril. 
An  interesting  feature  of  tins  ease  is  the  fact  that  the  fistulous  tract 
healed  in  a  couple  of  weeks  after  the  .r-ray  exposures  were  made.  The 
case  was  treated  1  >y  I  )r.  (liven  with  the  usual  antiseptic  and  stimulant 
applications,  both  l>efore  and  after  the  .r-ray  examination.  The  latter 
was  made  because  the  tract  had  refused  to  heal,  and  with  reference  to  a 
po--ible  operation,  the  necessity  for  which  was  obviated.  The  author 
reu'ard>  it  as  probable  that  the  exposure  to  the  ray  produced  a  beneficial 
effect  and  assisted  in  effect  mil  a  cure. 


Piu.  «;:$•_'.  —  Broken  drill  in  root-canal.  F'i-r.   G'-M.  —  Broken    in-trument    perforating 

the  root  laterally. 

A  case  of  nccroxis  and  fistula  may  be  shown  by  the  .r-ray  to  be  due  to 
a  retained  broken  root  of  a  tooth  or  to  a  fragment  of  root-filling.  The 
soft  materials  used  for  root-fillings  show  as  dense  bodies  in  a  radio- 
graph. 

/•'/•'ir/urt  of  Hit-  iiif'.-rior  mnxUla  shows  upon  a  film  held  inside  the 
mouth  (Fig.  »>:}!  >.  but  the  picture  is  often  difficult  to  make  owing  to 
pain.  A  radiograph  made  upon  a  plate  held  at  the  side  of  the  face  shows 
the  fracture,  but  usually  not  very  clearly. 


'"<!•     are   often    the   subject    of    investigation    by   the  .r-ray. 

'<  ctly   well  even  if  of  soft    material.     They  should  form  a 

ion-  opaque  mass,  occupying  the  pulp-cavity  and  the  root-canal 

I  m  perfect  ion  may  be  .-hown   bv  the  opacity  not 

|c  il  lorainen.  or  hv  break-  oceurrum  alonii  the  length 

tilling.  the  filliiiii-  extending  beyond  the  apical  foramen  or 

iiih    the  lai  :!1  of  the  root. 

--mii  of  cotton  would  iiot  -how  in  a  radiograph. 
ch  iii  the  root-canal  -how-  perfectly  in  a  radio- 
gra ph     I  !- .  i .:;•_'  . 


THE    .T-RAY 


949 


Metal  points  may  ho  introduced  into  tlio  root-canal  as  far  as  it  can 
ho  tracod.  Thoy  will  show  in  the  radiograph  and  ono  can  sec  whether 
they  are  in  the  root-canal  and  how  much  further  the  drill  must  ho  pressed 
to  reach  the  apical  foramen  (Fiji.  034). 

The  .r-ray  has  often  pro\-ed  of  service  in  the  author's  hands  in  the 
location  of  the  lesion  causing  a  chronic  fistula  when  two  or  three  regions 
were  under  suspicion.  The  cause  of  trouhlo  has  frequently  proved  to  he 
at  a  considerable  distance1  from  the  orifice  of  the  fistula. 

Cases  of  pijorrhca  alcculari*,  or  Riyg*  (li-waxe  (Figs.  035  to  037),  pre- 
sent lesions  which  show  in  the  radiograph.  There  may  he  deep  pockets 
along  the  root  of  the  tooth  from  absorption  of  the  alveolar  process,  and 
in  some  cases  the  process  between  the  roots  of  two  tooth  is  seen  to  he 
almost  gone.  A  pyorrhoal  pocket  shows  in  the  radiograph  as  a  space 
alongside  the  tooth,  opening  at  the  free  border  of  the  gum,  and  with 
apparently  hare  hone  and  tooth  down  to  the  bottom.  The  normal  con- 
dition is  for  the  root  of  the  tooth  to  be  seen  closely  embraced  by  a  dis- 
tinct layer  of  tissue,  called  the  peridental  membrane,  which  lines  the 
alveolus  or  tooth-socket.  The  alveolar  process  normally  projects 
between  the  tooth  to  about  the  commencement  of  the  crown;  the  portion 
surrounding  the  root  externally  and  internally  does  not  show  in  a  radio- 
graph, being  obscured  by  the  much  denser  substance  of  the  tooth. 


A  pyorrheal  pocket  is  sometimes  shown  by  the  .r-ray  to  be  due -to 

pressure  upon  the  root  of  the  tooth  by  an  unoruptod  tooth  or  by  a  mal- 
plarod  supernumerary  tooth.  The  pocket  in  such  a  case  usually  forms 
upon  the  side  opposite  to  that  upon  which  the  unnatural  pressure  is 
exerted. 

The  .r-ray  is  of  service  in  locating  the  roof-mndl  and  apical  formr/ai, 
for  instance,  in  cases  of  commencing  alveolar  abscess  whore  the  dentist's, 
drill  tails  to  find  the  proper  route.  Such  a  case  is  illustrated  by  Fiu. 
038.  There  were  the  pain  and  swelling  and  tooth  reaction,  which 
indicated  the  presence  of  pus  at  the  apex  of  one  of  the  roots  of  a  lower 
molar  tooth.,  but  nothing  to  show  which  root.  The  drill  did  not  readily 
follow  oil  her  root-canal,  and  the  dent  ist .  Dr.  ( iillett.  of  course,  could  not 
be  positive  that  the  canals  extended  in  a  perfectly  normal  direction. 
It  is  extremely  undesirable1  to  perforate  the  root  laterally.  Ho  placed 
a  little  metal  point  in  the  root-canal  as  far  as  it  had  been  traced.  The. 
radiograph  showed  the  abscess  at  the  apex  of  the  anterior  root,  and  also 


MKI>!<  AI.    KI.F.CTHICITY    AM)    R<>XT<;KN    HAY 


showed  that  the  metal  point  was  lying  in  exactly  the  right  direction. 
The  patient  returned  to  the  dentist  with  the  picture  in  less  than  an  hour. 
(iuided  by  the  picture,  the  drill  was  simply  pressed  straight  ahead  until 
something  was  felt  to  give  way  as  it  entered  the  abscess  cavity.  A 
couple  of  drops  of  pus  welled,  up  through  the  cavity  in  the  tooth  and  the 
pain  was  at  once  relieved. 

The  radiograph  is  valuable  as  a  guide  to  the  complete  removal  of 
tJtc  /"///>  from  cadi  root  to  its  very  extremity. 

A  frnrtun  nf  tin  root  of  a  tooth  shows  as  a  transverse  line,  but  in  the 
radiographs  of  the  upper  central  incisors  there  is  normally  a  transverse 
marking,  which  must  be  taken  into  account  in  making  the  diagnosis. 

furniture  of  tin  root  is  well  shown,  and  one  should  guard  against  the 
production  of  a  false  appearance1  of  flexion  or  curvature,  due  to  bending 
the  film  while  the  radiograph  is  being  made. 

The  lii/frnl  rnnts  of  the  upper  molar  teeth  ar:1  difficult  to  show  clearly 
unless  they  have  root-fillings.  The  best  way  to  accomplish  the  desired 
result  seems  to  be  to  hold  the  film  up  as  far  as  possible  on  the  inside  of 
the  mouth,  so  that  the  tube  will  not  have  to  be  placed  much  above  the 
horizontal  level  of  the  mouth.  A  somewhat  greater  distance,  and 
longer  and  stronger  exposure  than  usual  is  required.  To  make  still 
more  certain  two  radiographs  should  be  made  with  the  tube  at  decidedly 


Fit:.  H'V.i.     -Fir-t      upper     mnl:ir    root  Fitr.  '',(().  —  Kmpyrrna      of     tho      nn- 

fi'Tn-tr.-iiinir     imniiiil     .-minim.      I'yorrhc:il  tnitn.    Tin- upper  trrth  had  b««n  extracted 

•'    :iniiiinl   l.itrr:il    inri,,,r.  t'ur  -uppn-nl   nciiralfriii. 

different  lateral  angle.-,  but  still  not  so  far  to  either  side  as  to  cause  the 
image-  of  the  .-idjacent  teeth  to  overlap  th;ii  of  th<-  one  under  examina- 
1  he  [ile;:  of  placing  a  small  ./'-ray  tube  inside  the  mouth  and  the 
film  on  the  outside  doe-  not  seem  very  practical  (see  p.  771).  \Ve 
require  a  much  stroriLr<-r  apparatus  than  any  that  can  be  used  in  this 

\V:i  V. 

\   n'-tter  plan   than   this  is  to  place  the  tube  at   the  opposite  side  of 
.  and  at  a  somewhat  lower  level,  so  as  to  shine  through  the  open 
:'"d  produce  a  picture  upon  a  film  held  against  the  outside  of  the 
-      >  "'h  a  picture  may  show  also  both  antra  separatelv. 


THK    .r-HAY 


951 


The  object  nearest  the  film  is  always  depicted  most  clearly,  and  it 
almost  completely  obscures  the  other  if  the  two  images  overlap.  This 
explains  the  purpose  accomplished  by  taking  the  picture  of  a  buccal 
root  upon  a  film  held  outside  the  teeth. 

The  tube  is  enveloped  in  a  localizing  shield  with  a  sole-leather  disk. 
The  anticathode  is  11  inches  from  the  film,  and  the  exposure  is  about 
thirty  seconds,  with  a  penetration  of  Xo.  5  Benoist.  and  an  intensity  of 
No.  13  Tousey,  or  seven  and  a  half  seconds  with  an  intensity  of  No.  15 
Tousey. 

In  making  a  radiograph  of  the  ///>/>rr  niolurx  we  are  often  influenced 
by  a  desire  to  show  tin1  relation  of  iheir  roots  to  the  antrum,  and  also  the 
condition  of  the  antrum,  especially  as  to  the  presence  of  pus.  The  tube 
being  placed  at  a  higher  level  than  the  teeth,  the  image  is  apt  to  be 
somewhat  distorted,  and  allowance  must  be  made  for  this  in  estimating 


Fig.  0-1 1. — Normal  antrum.      Small  film  held  vertically  in  mouth.      C'asr  of  neuralgia  with 

all  upper  teeth  extracted. 


Fig.  64L'. — Normal  antrum.      Spicuhe  of  hone  have  heen  removed  along  the  alveolar  mar- 
gin.     Horizontal  film.      ( 'ase  of  neuralgia. 


the  length  of  the  different  roots.  The  buccal  root  is  apt  to  seem  much 
shorter  than  it  really  is  in  a  radiograph  made  with  the  film  inside  the 
mouth. 

The  radiograph  will  show  whether  a  root  penetrates  the  antrum,  as 
in  Fig.  (io'.t,  but  in  a  case  in  which  the  floor  of  the  antrum  dips  down 
between  the  lingual  and  buccal  roots  the  radiograph  would  seem  to 
show  both  roots  extending  into  the  antrum. 


i».)'J  MKim  AL  Ki.i:nKitiTY  AND  KONTOKN  KAYS, 

/)/>•<  (/,v(  N  of  tin  Antrnni  <i*  Xiiotrn  [  /><>//  a  Small  I'llni  JIdd  Inside  tJiC 
Mouth.—  A  hori/ontal  tilni.  like  Fig.  (>o9,  or  a  vertical  one,  like  Fig.  64], 
will  show  almost  the  entire  extent  of  one  antruni.  The  air  space  should 
seem  very  transparent  a>  compared  with  the  dense  teeth  and  even  the 
le--  dense  jaw  .-tructure.  A  marked  degree  of  opacity  in  the  antruni 
mean.-  pus  or  polypoid  or  granulation  tissue.  It  was  due  to  pus  in  Fig. 
till',  which  is  of  the  patient  whose  large  radiograph  of  all  the  pneumatic 
-inu-e-  i-  in ven  on  p.  IHiS.  All  his  upper  teeth  had  been  removed  for 
pain,  which  was  thought  to  l>e  of  neuralgic  origin. 

A  larger  plate,  showing  the  entire  face,  either  laterally  or  antero- 
po.-ieriorly.  is  a  necessary  part  of  the  examination  in  most  cases.  It 
-how-  tlie  extent  to  which  the  disease  has  involved  the  other  pneumatic 
sinuses. 

Tinnitus  atirium  was  the  symptom  which  led  to  an  .r-ray  examination 
in  one  of  Schamberg's  cases.  The  radiograoh  showed  pyorrheal  pockets 
aliout  tiie  root.-  of  some  of  the  teeth  communicating  with  the  antruni 


by  :•.  -mall  opening,      Fxtraction  of  the  affect e<l  teeth  and  syringing  the 
antrum  cured  the  ear  symptoms.1 

The  roots  of  the  teeth  do  not  usually  extend  beyond  the  level  of  the 
hard  palate.  The  portion  of  the  upper  jaw  below  that  level  is  the  al- 
veolar process  and  is  absorbed  after  the  teeth  are  lost. 

A  tooth  which  has  been  injured  in  any  wav,  or  which  has  been  ex- 
tracted or  knocked  out  and  reimplanted,  may  present  symptoms  point- 
ing to  absorption  ot   it>  root.     Several  such  cases  have  been  examined 
y  t  he  a ut  ho r.  and  in  each  case  t  he  radiograph  has  shown  whether  there 
ha.-  been  any  absorption,  and.  it  so.  to  \\  hat  extent  i  Fig.  (144). 

The  radiograph  will  show  the  condition  of  the  roots  of  teeth  which 
loiin  i  he  anchorage  for  or  are  held  in  place  by  crown  and  bridge  work 
Fin.  ill."  . 

Ill'-  root-  of  a  crowned  tooth  may  be  examined  to  determine  the 
'i'  'j"-<-  ot  ab.-oi'i  it  ion  \\lnch  has  taken  place. 

'  I, m  it.-  '/.  lln  X<rn  <>r  ]'//'/>  <>f  n  Ttmth.-  A  -liuht  irritat  ion  will  not 
b<-  recognizable  by  the  .r-ray.  but  if  it  i-  severe  it  will  produce  an  area 
o]  iran-hicencv  around  the  apex  ot  the  root  indicating  an  incipient  al- 
V-olar  ab-ce--s; 

/'•  1 1-  '"' '    .       I  he-e   concret  ion-   sho\\    as    \  er\'   defined   opacnie  ob- 
:    the    pul])-cavity    of   the    tooth.      They    -ometimes,    as    in    Fig. 
lib".  :          like  exo>to-e-  tVoin  the  bony  wall  of  the  pulp-chamber. 

'•-    Hunt.-  ,,f  Ti<th  C(iii*iit,'n    ,>f  T/il,()riiloniv-    ( '1 1  r(  niic  ab- 


THK    .T-UAY 


953 


seesses  at  the  roots  of  tooth  have  boon  observed  by  J.  Zilz1  as  an  active 
starting-point  for  tuberculosis. 

.r-h'dij  Findings  in  (V/xr.s  of  1'neniptcd  Teeth. — The  uneruptod 
superior  canino  (Fig.  (>4(>)  is  usually  found  to  bo  present,  and  generally 
lios  in  a  direction  more  nearly  parallel  with  the  median  line  than  nor- 
mally, and  usually  on  the  lingual  side  of  the  other  teeth.  If  it  presses 
against  the  root  of  the  lateral  incisor  a  cvst  cavitv  (Fiji.  (>40)  is  often  to 


readilv  seen  in  lookintr  at  the  film 


be  soon  there.     The  unerupted  lower  third  molar  is  almost  always  found 
and  frequently  impacted  (Fig.  047). 

The  other  molars  and  the  bicuspids  if  much  delayed  in  eruption  are 
fully  as  apt  to  be  found  entirely  absent  as  to  bo  present.  It  is  a  very 
serious  mistake  to  extract  a  persistent  temporary  tooth  in  any  of  the 
locations,  as  was  done  in  Fig.  048,  without  first  using  the  .r-ray  to  find 
out  whether  the  permanent  tooth  is  present. 


'reviously      unsuspected"     cyst 


A  question  sometimes  arises  as  to  whether  a  certain  tooth  is  a  per- 
sistent temporary  molar  or  a  permanent  bicuspid.  A  radiograph  of  the 
tooth  shows  which  it  is,  and  if  it  is  a  persistent  temporary  tooth  the  pic- 
ture shows  whether  the  germ  of  the  permanent  tooth  is  present  (Fig. 
1)49)  or  absent  i  Fig.  (ioO). 


954 


MKDICAL    KLKlTKU'ITV    AND    KONTCiKX    HAYS 


Radiographic  examinations  show  that  absorption  of  the  root  of  a 
temporary  tooth  is  not  entirely  due  to  pressure  of  the  oncoming  per- 
manent tooth,  but  is  a  natural  process  which  sometimes  occurs  when  the 
permanent  tooth  is  completely  absent  (Figs.  (>.~>1  and  1)52). 

The  most  remarkable  case  in  the  author's  experience  is  that  of  a 
young  man.  a  patient  of  Dr.  Allan,  who  at  the  age  of  twenty  years  still 
had  every  one  of  his  first  teeth.  A  series  of  radiographs,  including 


traeted. 

Fiir.  <>.">:•).  revealed  the  presence  of  all  the  permanent  teeth  still  unerupted. 
The  smallness  of  the  first  set  of  teeth  gave  an  infantile  expression  to  the 
face,  so  for  looks  a  complete  set  of  false  teeth,  upper  and  lower,  were 
worn.  The  patient  was  thus  going  around  with  three  complete  sets  of 
teeth. 

The   radiograph   will   locate  an   unerupted  second  molar  and  show 
whether  it    is  obstructed  or  is  pressing  upon  the  first   molar.     Such  an 


1  -'.'!'•'•    n!     L'erm    of    permanent        per     lateral     under^oiim     absorption,     a 


examination  would  be  desirable,  as  suggested  by  Hopkins,1  in  the  case 
ot  ;i  i-hild  M|  ten  or  twelve  years  suffering  from  fret  fulness  and  loss  of 
appetite,  \\nli  iiTit:ited  eyes  and  ears,  anemia,  and  nervousness  bor- 
dering < m  h v-t rria . 

1   iienipted  teeth  are  often  seen  to  lie  in  a  kind  of  capsule,  and  very 
valuable   mtorniat  ion   as   to   their  probable  period  of  eruption   may  be 
Jour     \n,> T.   Me,l.  Assor.,  June  :;o,   I'.MIti,  p.   I'tv.t. 


TIIK    X-KAY  <),-,.-, 

gained  from  the  degree  of  development  of  the  tooth.     This  is  perhaps 
more  important  than  its  proximity  to  the  surface. 

Prolonged  Retention  of  Deciduous  Teeth  or  Their  Itootx.-  The  roots  of 
these  teeth  sometimes  fail  to  l>e  absorbed  and  deflect  the  oncoming  per- 
manent tooth.  A  radiograph  will  show  whether  the  roots  in  question 
are  undergoing  absorption  or  not. 


Portion  of  upper  jaw   in   a 
"••    teeth    persistent 


Fig.  652. — Persistent  temporary  upper  Fig.   653. — Portion  of  up 

molar  undergoing  ahsorptioii,  although  per-        case    with    all    temporary    tee 
nianent  germ  is  absent.  at  the  age  of  twenty  yeans. 

Flint1  cites  many  ways  in  which  the  .r-ray  gives  valuable  informa- 
tion in  orthodontia. 

Radiographic  Measurement  of  the  Permanent  Teeth  Before  Eruption  to 
Provide  for  Early  Regulation  of  the  Dental  Arch  if  Their  Size  Necessitate*  It. 
-This  was  the  title  of  an  article  read  by  the  author  before  the  N.  Y.  In- 
stitute of  Stomatology,  November  9.  190(5.  It  was  suggested  by  Hawley'* 
investigations  in  regard  to  the  relation  between  the  size  and  shape  of  the 
dental  arch  and  the  size  of  the  different  permanent  teeth.  Dr.  Gillett 


Fig.  654. — Angle  at  which  the  r-ray  must  he  directed  in  order  that  the  image  of  a  tooth 
upon  a  horizontal  film  shall  he  about  the  actual  length. 

called  my  attention  to  the  advantage  to  be  derived  from  an  accurate 
measurement  of  the  different  permanent  teeth  a  year  or  two  before 
their  eruption.  Acting  upon  this  idea,  the  author  has  made1  radio- 
graphs of  the  temporary  and  unerupted  permanent  teeth  in  about 
100  children.  While  there  was  every  reason  to  believe  that  such  pic- 
tures would  give1  an  idea  of  the  relative  size  before  eruption,  it  seemed 
very  desirable,  indeed,  to  make  a  series  of  measurements  to  find  out  also 
how  much  magnified  or  reduced  the  .r-ray  image  of  the  erupted  teeth  was 

1  Dr.  D.  W.  Flint,  Dental  Cosmos,  Nov.,  1907. 


MKDICAL     KI.Ki  "I  'UK  '1TV    AND    KO\T<;K\     HAYS 


as  compared  with  measurements  made  at  the  same  time  from  the 
actual  teeth  themselves.  The  leelh  which  had  already  erupted  were 
measured  bv  means  of  a  caliper  square,  graduated  in  hundredths 
dt'  an  inch,  and  at  another  time,  without  reference  to  these  measure- 
ment-, others  were  made  of  the  same  teeth  ;:s  represented  in  the 


j 


li'i.'i    i .' ,( i        l'.-ulioLrr:iph~    u-ed    in    ine.'isiirilif:    the    uidth    ot'    the    upper   or   lower 

:),<  i  -ur  •   before  i  TII  pi  i'  ni   to   pro\  i'  le   for  e:irlv  ri'Uiihi  I  ii  m    in   csisc  t  hoc   Icctli   :irc  too 

.  tor  tin'  nri'li.       lii    I  \<_'.  IK'S,   \vln-ri'   one  cc-nti-nl   li:nl   rrnptcil    and  the  other  li:nl  not, 

1     -    ;      irenielil        were    ec|ii;il.        In     -Hell     pictures    ;is  05U     it     i.^  e:is\'    'o  >ee 

o    i  he  i-eiil  :•:,!  ini-i>or  <ir  tooth  tn  our  riiiht  i-  correct  1\-  shown.     'I  he  one 

r  1--M  i  I  irom  t  he  ~i.!e. 


;  !    .     T'h*1    lateral    measui'<vmeiit s    correspond<'(l    to    within 

our   purpose,    it    is    fortunately    not    neressarv   to   have  an 

f    measurin«r    the    actual     vertical     length     of    the    teeth. 

•.'!••(•  of  accuracy,  however,  can  he  obtained  by  holding 

•    the  proper  an.irle  ( Fijr.    (i.")li.      It  is  very  note- 

worthy  tli:  phs  show  that  the  sixe  of  the  teniponuy  teeth 


TIIK    .T-HAY  :»•)/ 

does  not  furnish  any  accurate  indication  of  the  sixe  of  the  permanent 
unerupted  teeth.  Some  of  the  largest  unerupted  permanent  upper 
central  incisors  are  found  in  cases  in  which  the  corresponding  tem- 
porary teeth  are  medium  or  small.  (Figs.  Goo-OOO  are  examples  of 
this  work.)  The  radiographs  and  measurements  have  been  made 
especially  in  children  of  from  four  and  a  half  to  seven  years  of  age,  and 
in  these  cases  attention  has  been  directed  chiefly  to  measurements  of 
the  upper  and  lower  incisors.  The  author  has  also  taken  an  impression 
of  both  upper  and  lower  dental  arches  by  having  the  child  bite  upon  a 
sheet  of  wax  placed  horizontally  in  the  mouth.  Another  class  of  cases 
in  which  radiographic  measurements  are  valuable  are  the  patients  oi 
young  or  middle  age  who  have  persistent  temporary  teeth,  and  in  whom 
the  .r-ray  reveals  the  absence  of  the  permanent  tooth  or,  if  it  is  present, 
shows  its  sixe  and  direction.  Closely  akin  to  these  are  the  cases  in 
which  the  natural  loss  of  the  temporary  tooth  has  riot  been  followed 


by  the  eruption  of  the  permanent  tooth.  In  both  of  these  classes  of 
cases  the  relative  sixe  of  the  unerupted  tooth,  as  compared  with  the 
adjacent  permanent  teeth  shown  in  the  picture,  gives  at  a  glance  the 
indication  for  proper  spacing  in  order  to  allow  of  its  eruption,  and 
measurements  in  hundredths  of  an  inch  or  fractions  of  a  millimeter  are 
not  usually  required. 

The  author  is  indebted  to  Dr.  J.  Lowe  Young  for  making  measure- 
ments of  the  actual  teeth  in  several  of  these  cases,  and  for  suggestions 
as  to  the  selection  of  the  instruments  used  for  such  measurements.. 

At  a  clinic  given  before  the  National  Dental  Society,  Washington, 
1012,  the  author  reported  further  upon  this  method: 

Imperfect  development  of  the  teeth  is  not  only  a  disfigurement,  but 
renders  proper  mastication  impossible  and  the  proper  action  of  the 
saliva  unlikely.  The  immediate  effects  are  starchy  indigestion  and 
irritation  from  unmasticated  meat  with  auto-intoxication  from  both. 

In  the  young  child  "the  nasal  passages  are  lined  below,  in  front,  and 
on  both  sides  by  the  germs  of  the  teeth"  (Dr.  Strangi,  and  imperfect 


lioS 


MKD1CAL    Kl.KCTHICITV    AND    RONTGEN    KAYS 


»    I'.liL'.   -Xarrow  curve  f  on  HIM!  },\-  the  temporary  teeth  in  a  rase  in  which  the  permanent 


teeth  were  .-howii  l>v  tlie  .r-ray  to  require  a  broad  curve.     (Knl 


i\-  the  permanent  teeth  in  the  same  ea-e  as  Fill.  GC'L'  is  still   too 


rn,\\   for  |ieriii:irii-iit  teeth  of  t  ha1   -l/.c.      (Knlarficd.) 


oi   the  teeth  ;MM|  <it  the  iiinxiliarv  hones  support inji  thoni 


iii;ili|cvcl()|)ii)cn1    in  the  tmny  \v;uls  of  the  nusal  passages  and 


;  it  ic  ^H  i  u>c>  o!  t  lie  lace,  and  the  effect  of  undenlevel- 


r.   e\-cn  extend  to  the  craiMai  cavity  and  the  I'l'aiu. 


THE    OXRAY 


959 


Deviations  of  the  septum  and  mouth-breathing  unrelieved  by  the 
removal  of  adenoids  and  Tonsils,  are  among;  the  results  of  maldevelop- 
ment  of  the  teeth  with  a  too  narrow  and  too  highly  arched  hard  palate. 

The  object  of  my  most  recent  work  has  been  to  determine  beforehand 
the  presence  and  position,  and  especially  the  size  of  the  permanent  teeth, 
before  the  loss  of  the  temporary  teeth.  The  latter  may  be  quickly  and 
easily  trained  to  a  curve  of  the  proper  radius  and  will  then  guide  the  per- 
manent teeth  into  proper  position. 

ACTUAL  WIDTH  OF  TEMPORARY  AND  PERMAXEXT  CEXTRAL  INCI- 
SORS (THE  LATTER  MEASURED  SOME  YEARS  LATER)  IX  HUX- 
DREDTHS  OF  AX  IXCII. 


ht   upper 
entral. 


Xanii'. 


Matthew  S.. 
Clara  T.  .  .  . 
(  Yeelia  L.  .  . 
C.retchen  W. 
Margaret  F. 
Florence  Y  . 

Sissie  R 

Jeanette  S.  . 
Xora  F.  . 


Ratio 

1  to 


s 
1(1 

9 

10 
10 
10 
10 

S 

6 


24 

21 


3s   1..V2 
30   1.50 
33   1.30 

29    1.1C> 
33    1  .25 
34    1  .3(1 
30    1  .57 
31    1.3S 
35 

15 
15} 

14 
1C)1, 
14 
11 

2-U 
22 

21 
19 
21 
21 
23 

1.03 
1.42 

1  .30 
1  .28 
1  .50 
2.09 

Actual  measurements  of  the  temporary  teeth  bear  no  fixed  ratio  to 
actual  measurements  of  the  permanent  teeth.  In  a  series  of  7  cases, 
shown  in  table  above,  the  ratio  varied  oO  per  cent;  in  the  same  cases 
untreated,  the  curve  of  the  temporary  arch,  whether  suitable  for  the 
permanent  teeth  or  not,  was  reproduced  in  the  permanent  arch.  A'-ray 
measurements  of  the  width  of  the  imerupted  permanent  upper  and 
lower  central  incisors  at  the  age  of  five  or  six  years  correspond  within 
-y-Jf,;  inch  with  the  actual  measurements  of  the  same  teeth  five  years 
later,  after  eruption,  as  shown  in  the  following  table. 

PERM  \XEXT  CEXTRAL  IXCISORS  MEASURED  R  ADIOC.RAPHICALLY 
BEFORE  ERITT10X  AXD  ACTUALLY  SOME  YEARS  LATER  AFTER 
ERUPTIOX.  (Xumbers  arc  in  Hundredth*  of  an  Inch.) 


Tooth. 


Radiograph 
uiicniptcd. 


Matthew  S. 
Clara  T.  .. 
Clara  T.  .    . 
Cecelia  L. 
(iretchen  \V 
Florence  R.. 
Sissie  R  . .  .  . 
Jeanette  S.  , 
Jeanette  S.  . 


Left   1 

"pper  (  '(Mitral 

39 

Hinlit 

Upper  C 

Mitral. 

30 

Right 

Lower  (  ' 

Mitral 

•>•> 

Right 

Upper  C 

Mitral 

34  oblique 

Right 

Upper  C 

Mitral 

29 

Right 

Upper  C 

Mitral 

35 

Left  1 

"pper  Central 

30 

Left  Upper  Cnctral. 
Right  Lower  Central. 


32 

21 J 


MF.DICAI.    KLKCTKICITV    A  XI)    HoXTOKX    HAYS 


The  author'.-  technic  is  as  follows:  The  temporary  centrals  arc  meas- 
ured with  a  sharp-pointed  ealiper  square  with  a  screw  adjustment,  and 
graduated  in  hundredth*  of  an  inch.  A  wax  impression  ot  the  curve  of 
the  temporary  upper  and  lower  arches  is  made.  Radiographs,  or  .r-ray 
pictures  i  Kins.  002  and  00^:.  are  made  of  the  unerupted  upper  and 
lower  central  incisors  and  the  width  of  the  images  of  these  teeth  is  meas- 
ured i  Kig.  004  i.  A  curve  suitable  for  permanent  teeth  of  this  size  is 
calculated  by  a  modification  of  Hawley's  and  Bomvill's  tables.  My  work 
shows  the  sixe  that  the  permanent  teeth  will  have  and  the  radius  of  the 
curve  required  to  acconiodate  them.  The  temporary  bite  is  photographed 


f  p<-n!i:ti!>-tit  (l<-nt;d  r-irdc  fron.  .r-nty  mi'it-urr-mciit  of  the  upper 


:  the  actual  curve  formed  by  the   cuttinir  edires  of   the   incisors,  the 

i-  ot    the  canines,  and  the  buccal  cusps  of  the  bicuspids  and  molars, 

upon  the  -ame  photograph  is  drawn  the  correct  curve  i  Kig.  005)  to 

mirnodate   permanent    teeth   of    the   -ixe  determined   by   the  x-ray. 

idonlisi    may  regulate  the  temporary  teeth  to  this   curve,  and 

uide  t he  permanent  teeth  into  proper  position  as  they  erupt.    Kigure 

how-  the  -Mine  case  as  Kig.  002,   in  winch  the  temporary  curve  was 

li  for  permanent  teeth  of  the  size  shown  by  the  .r-ray.     The  ca>e 

;.  and   five  years   later  the  curve  formed   by  the  erupted 

'eetl i  v,  ;t-  ,i  contracted  one  of  the  -ame  radius  as  that  origin- 

•  he  temporary  teeth. 


THK    .r-KAY  91)1 

Take  the  width  of  one  permanent  upper  central  incisor,  double  it, 
and  add  0.24  inch  to  get  the  radius  of  the  circle  formed  by  the  six  upper 
front  teeth  (cutting  edge  of  incisors  and  cusps  of  canine).  Add  ~>0  per 
cent,  to  t  hat ,  and  you  have  t  he  distance  in  a  straight  line  from  the  middle 
of  the  anterior  surface  of  the  first  permanent  upper  molar  to  the  space 
between  the  two  centrals. 

After  drawing  the  circle  use  the  radius  from  A  to  get  the  distal  points 
of  the  canines  ./  and  //.  From  (',  draw  lines  through  ./  and  //  to  the 
tangent  and  so  get  /','  and  I).  I'se  /•,'  I)  as  radius  of  a  circle  whose  center 
is  at  /.  Starting  from  A  in  both  directions  measure  off  the  length  of 


the  radius  six  times  and  so  get  the  inscribed  isosceles  triangle,  .-1,  F.  C '. 
Draw  lin<'-  //.  ( '  and  ./.  /•".  The  outer  cusps  of  the  bicuspids  and  molars 
lie  alonu  the-e  two  straight  lines. 

The  marvelously  beneficial  effect  of  <ufliciently  widening  the  dental 
arch  i-;  -hmvn  in  the  diagrams  of  the  na~al  septum  (Fm-.  (i(>(>)  drawn  by 
llif  rhinologist,  Dr.  IVren^,  after  treatment  by  the  dentist.  Dr.  K.  A. 
Bogue. 

Stfi'cnxcopfc  RfHlioijrnphs  in  D/i/lnl  II  nrl:.  Two  types  of  radiographs 
are  available:  one  upon  two  successive1  films  held  inside  the  mouth,  and 
the  other  upon  two  successive  films,  or  plates,  held  against  the  outside 


MKD1CAL    KI.KCTKMITY    AND    KoXTCKX     KAYS 


of  the  fare.  The  latter  pictures,  like  Fig.  (iCiT,  .1  and  7>,  take  in  a  wide 
area  and  show  the  topography  of  the  teeth,  upper  and  lo\ver  jaws, 
and  tongue  in  their  natural  perspective.  The  pictures  may  he  made 
upon  small  films  held  inside  the  mouth  when  the  perspective  of  the 


a 


l-'in.  6P>6.— Deviations  of  the  nasal  septum  in  a  youi'tr  child  straightened  in  a  few 
weeks  by  regulation  of  the  teeth.  (Dental  treatment  by  Dr.  K.  A.  Hogue;  nasal  exam- 
inaticiti  and  diagrams  by  Dr.  Herons..) 

roots  of  an  individual  tooth,  or  that  of  the  roots  of  adjacent  teeth,  or  of 
an  unerupted  tooth  and  the  roots  of  the  neighboring  teeth,  is  desired. 
The  object  in  the  latter  case  is  to  find  out  whether  the  unerupted  tooth 
is  on  the  buccal  or  the  labial  aspect.  It  is  easy  to  misinterpret  a  pair 
of  these  little  stereoscopic  pictures  if  they  are  pasted  in  the  wrong 
positions  upon  the  card,  so  that  the  left  eye  looks  through  the  stereo- 
scope at  the  picture  which  should  bo  placed  before  the  right  eye. 


pie  radiograph  of  the  upper  and  lower  iuws. 


I  he  -mall  stereoscopic  pictures  are  made  in  the  same  way  as  dental 


evepl    lh:il    two   -eparate   exposures   arc    made   upon    suc- 

'    film-   held  in  exactly  the  same  portion  in.-ide  the  mouth,  while 

moved  '_!.',   indie-  laterally  before  taking  the  second  picture. 

iioper  di-placement    lor  rjidiogi'aplis  made  upon  a   hon- 

ii   the  aiit  icathode  about    \'.\  iiirhe.-  di.-lanl    from  the  film. 

I!  inrhe-  i.-  bet  ter  where  an  external  plat  e  is  used  and 

''.   I;  che>.      I  U)l  h   of   t  IICM    \  i.  Id   good   results,   be- 

rau-i    i  I  •  i    po-ii  ioii  of  the  pa  !  ient   and  I  he  film  or  plate  and  I  he 


TIIK    .r-HAY 


903 


x-ray  tube  may  bo  exactly  duplicated.  They  both  show  the  perspective 
of  a  large  part  of  the  jaw,  and  (lie  posit  ion 'of  (ho  unerupted  as  well  as 
the  erupted  teeth. 

The  smaller  films,  held  parallel  with  the  axis  of  the  teeth,  present 
greater  difficulties  in  securing  the  same  relative  position  of  patient  and 
film  and  .r-ray  tube,  and  are,  therefore,  less  apt  to  yield  satisfactory  re- 
sults. The  anticathodc  should  be  13  inches  from  the  film,  and  should 
be  displaced  4  inches  before  the  second  picture  is  made.  These  pictures, 
if  successful,  show  the  perspective  of  parts  of  an  individual  tooth,  and' 
for  example,  would  reveal  the  fact  that  a  root-filling  perforated  the  root 
either  buccally  or  lingually. 

Fig.  fiOS  shows  the  principle  upon  which  this  is  based.     The  position 

"!.,  tn<\tul)0  in  the  first  picture  is  marked  T1  and  in  the  second  picture 

Two  bodies  at   different  distances  from  the  film  an;  marked  by  a 

square  (D)  and  a  triangle  (A)  cast,  the  images  marked  (D1)  and  (A'j  in 


f  r 


the  first  picture  and  (C'J)  and  (A'2)  in  the  second  picture.  These  four 
images  are  not  all  upon  the  same  film;  (~.])  and  (A1)  are  upon  one  film, 
and  the  other  two  upon  1  he  second  film. 

A  moment's  study  will  show  that  motion  of  the  tube  in  one  direction 
disj  daces  1  he  images  of  all  bodies  m  the  opposite  direction.  Object  s  at  a 
distance  from  the  film  undergo  greater  displacement  than  those  near  it. 
Examining  the  two  pictures,  we  should  find  that  the  image  of  the  object 
further  from  the  film  is  displaced  in  the  opposite  direction  (with  refer- 
ence to  the  object  nearest  the  lirnn  from  that  in  which  the  tube  is 
shifted.  The  author  likes  this  method  of  studying  the  two  small  pic- 
tures better  than  by  combined  vrsion  with  the  stereoscope. 

If  the  stereoscope  is  to  be  used  care  must  be  taken  to  hold  the  film 
with  its  sensiti/ed  surface  toward  the  .r-ray  tube.  The  print  made  from 
the  film  exposed  with  the  .r-ray  tube  farthest  to  the  patient'-  ief;  should 
lie  pa-ted  upon  the  card  so  as  to  be  looked  at  with  the  observer's  right 
eye,  and  the  print  from  the  other  film  is  looked  at  with  the  left  e\  e. 
The  perspective  is  then  as  if  the  observer's  eyes,  placed  in  the  two 
positions  of  the  .r-ray  tube,  looked  at  a  transparent  jaw.  objects 
which  look  farthest  away  are  on  the  lingual  aspect:  tiio>e  that  look 
lira  re!1  a  re  on  t  he  1  uiccal  asj  tec1. . 


'.Mil 


i:u:<  nJii  ITY   AND   KO.NTCKN   KAYS 


I)i  terininiition  of  I\  rxj>c<'tirc  in  a  Sintjlc  Kiufiot/rtifih  of  tfic  Tcelfi. — 
The  determination  of  the  relative  position  of  two  teeth  whose  images 
overlap  each  other  can  usually  be  made  by  a  careful  study  of  a  single 
radiograph.  The  ima^e  of  the  tooth  nearer  the  plate  i.-  markedly  more 
distinct  and  clearly  defined.  Fig.  (>(19  shows  this  fact.  The  image  of 
the  unerupted  canine  i<  only  rendered  denser  by  the  presence  of  other 
teet  h.  while  t  he  images  of  t  In-  hit  ter  are  obscured  and  rendered  less  easy 
to  tract'  where  the  overlapping  occurs. 

Where  the  imaires  of  the  adjacent  borders  of  two  teeth  overlap  in 
an  .r-ray  picture  the  image  is  more  than  twice  as  dense  as  that  of  either 
of  the  thin  borders  alone.  Successive  portions  of  dense  substances  ab- 
sorb more  and  more  of  the  rays  which  have  an  effect  upon  a  sensitized 
film.  After  traversing  a  certain  thickness  of  dense  tissue  the  radiation 
produces  no  visible  effect  upon  the  film. 

Radiography  of  the  Inferior  Denial  A'ew.— Radiographs  of  the  bony 
canal  which  this  nerve  traverses  in  the  lo\vr  jaw  may  be  made  in  two 
ways. 

A  film  ]]'•  2  inches  long  may  be  held  inside  the  mouth  and  pressed 
clo-ely  again>t  the  inner  surface  of  the  jaw  from  the  region  of  the  canine 
tooth  backward.  The  upper  margin  of  the  film  should  not  be  above  the 

crowns  of  the  teeth,  while  the  lower  margin 
should  extend  well  below  the  roots.  The 
.r-ray  tube  should  be  at  the  «ame  side  of  the 
face  and  opposite  the  second  molar  tooth  at 
a  distance  of  14  inches  from  the  anticathode  to 
the  film.  The  .r-ray  should  be  of  a  high  de- 
gree of  penetration.  Xo.  S  Benoist,  and  the 
exposure  will  be  twelve  seconds  with  a  12-inch 
coil  or  about  one-fourth  -econd  with  an  un- 
fluctuating converter  or  a  transformer.  The 
object  is  to  obtain  a  picture  showing  as  great 
detail  as  possible  in  the  bony  structure  of  the 
jaw.  even  at  1  he  expense  of  a  certain  degree  of 
'  cont  rast  in  the  radiograph. 

Fig.  t'»71  -hows  a  gold  plug  in  the  inferior 
"'"•    dental   canal.      It    wa-  placed  there  six  years 
previously,    to    prevent     regeneration    of    the 
nerve  after  re-ection.      It  could  be  seen  very 
_    fluoro-cope  and  the  .r-ray  tube  held  at  the  oppo- 
the   lace.      I;    -eemed    to  be  acting  as  an  irritant   foreign 


other  method   i-  to  make  a   radi-  .graph  on  a   plate  held  at   the 
t   the  jaw  with  the  .r-ray  tube  at    the  opposite  nde  of  the  face. 
a  level  as  to  shine  from  under  the  opposite  side 
r  it    may   lie  directly  opposite  and  .-hine  riirht 
cide<,    but    xi   near  thai    while   the   image  of  the  affected 
learly  defined   that   of  the  opposite  side  is  enlarged  and  vague. 
'i  the  expo-ure  -hould  be  rather  long  and  strong,  and  the 
'   penetration  rather  hiyh      penetration.   No.  s  Benoi.-t  ;  exposure 
l,  or  about  one  -econd  with  a  transformer 


12-inch  c 

latino  con  vi  Tt  e 
v  "t"  the  br. 
-  an  iin-u~p 


TIIK    .T-RAY 


Radiography  of  the  Inferior  Maxilla.- -Under  this  heading  rnay  bo 
described  tho  making  of  a  picture  upon  a  pinto  hold  against  tho  outside 
of  tho  faoo,  tho  tube  being  at  th.o  opposite  side  of  tho  patient.  Such  a 


Fig.  070. — Inferior  dental  canal  in 
case  ot'  neuralgia.  The  teetli  had  been  ex- 
tracted long  lx;fore. 


Fig.  671. — Arrow  points  to  gold  plug 
plaeed  in  inferior  dental  canal  after  resee- 
t ion  of  the  nerve. 


picture  does  not  give  as  good  an  image  of  any  of  the  teeth  as  the  other 
method,  but  it  does  enable  us  to  radiograph  the  articulation  of  the  jaw 
and  to  examine  the  condyle  and  ramus  of  the  jaw  for  a  fracture. 


uf.  li7J. — Radiography  of  the  inferior  dental  nerve  upon  a  plate  outside  of  the  face 


pic  plate-holder  i-  shown. 


plate  in  it.-  opaque  envelopes  can  be  ex- 


chtuiged  for  another  without  unv  movement  on  thr  part  of  the  patient 


Throe  methods  are  excellent:  Fir*t,  a  pair  of  stereoscopic  radio- 
graphs, ant icat hode  21  inches  from  tho  plate,  and  vertically  over  the 
external  auditory  moatus  in  one  picture,  and  over  the  front  of  the 


MKDH  AI.    KI.K(TKiem     AND     KONTCHN     KAYS 


mouth  in  tlu-  companion  picture.  Distance  '2'^  inches  exposure  for 
each  picture  .Vmdi  resistance  or  >park  equivalent ,  (\~)  kv.,  ol)  ma.  for 
three  secoiuls  or  10  ma.  for  nine  seconds,  for  a  l.'iO-poiiiHl  man,  with  an 
iiitc-n-'ifviiiii'  scieen.  or  two  oi1  three  times  the  duration  without  one. 
Further  detail<  of  thi-  met  hod  are  i:iven  under  the  head  of  stereoscopic 
radiography.  As  applied  to  the  face  it  ;i'ives  tiood  anatomic  detail,  for 
in-taiice,  of  the  variou-  pneumatic  sinn>es. 

Seconil,  the  tulie  and  the  head  may  he  so  placed  lhat  the  .r-ray  will 
shine  under  the  opposite  >ide  of  the  jaw  and  through  the  (loor  of  the 


Mini    I  he  ;i!'t'ec1cd  side  of  tlie  jaw.   the  plate  lieinu'  ;it    tha.1    side  of 
ice.       \Viih    a    liltie   care   a    picture    ina\     lie   cihtained    in    which    the 
-  of  aluiK-1    thi     entire   r:imtl.<  and    half  of  the   liody  of  the  lower 
••      '    iwn,    llii-  imaire  of  the  oppo-ite  -ide  of  the  j;i\\-  falling  at   a 
i  i  on  'he  pl;iie.      The  exposure  i-  the  -ame  as  for  the  pre\ious 

•    •      '       •    I ime  i-  required. 

normal  art  iiaila!  ion  of  the  lower  jaw  ( Fiir.  (\7'.\) 
;ih    clo-ed    or  only   -liuhtly    opened    -how    the   con- 
rlyio  '         .deiioid  fo>~a.      \\ith   wider  o)enin^  tli(%  con- 


TIIK    .r-HAY 


%7 


forward  upon  the  eminentia  articularis.  A  dislocation  is  shown  as  an 
exaggeration  of  this  normal  displacement  1o  a  point  beyond  the  emi- 
nent ia  articularis. 

The  conditions  revealed  by  the  x-ray  in  a  typic  case  of  long-standing 
ankylosis  of  the  jaw  are  described  byCryer.1  The  angle  of  the  chin,  or 
mental  process,  is  drawn  back  and  the  angle  of  the  jaw  downward. 
These  are  due  to  imperfect  development  under  the  abnormal  conditions. 

The  ./--Ray  in  the  Differential  Diagnosis  of  Facial  Neuralgia. — The 
x-ray  has  an  undoubted  action  in  relieving  pain,  as  shown  in  cancer 
and  rheumatism,  and  it  is  effective  in  many  forms  of  neuralgia.  There 


are  certain  cases  in  which  the  nature  or  the  position  of  the  pathologic 
lesion  renders  a  curt1  impossible  except  by  surgical  removal  (.if  the 
cause  of  the  trouble.  The  x-ray  will  often  be  of  service  in  the  differential 
diagnosis  of  neuralgia. 

A  case  illustrating  this  is  shown  in  Fiu1.  (174.  The  patient.,  a  lady 
about  fifty  years  of  au~e,  was  sent  to  me  for  Kontgen  diagnosis  by  Dr. 
X.  B.  Potter  of  this  city.  She  had  >ui'fered  for  three  years  from  very 
severe  pain  near  the  angle  of  the  lower  jaw.  all  the  teeth  except  the  last 
molar  had  been  extracted  from  that  part  of  the  jaw  without  relief.  Med- 
ical treatment,  phototherapy,  and  electrotherapy  had  been  applied  by 
'  Dental  Cosmos,  Jan.,  llHI").  p.  1.1. 


MF.lHi  AI.     Kl.F.c  TKH  11  V     AND    KoNTCKN    HAYS 


specialists  in  Now  York  and  Paris  without  success.  An  operation  was 
under  consideration  for  removal  of  the  (lasserian  ganglion,  or  of  the 
origin  of  the  third  division  of  the  fifth  cranial  nerve.  The  radiograph 
was  taken  with  the  affected  side  of  the  patient's  face  lying  upon  the 
plate  and  with  the  .r-ray  tube  above  the  opposite  side  of  the  face.  This 
.Allowed  a  large  molar  tooth  imbedded  in  the  jaw-bone  behind  the  only 


ilar  ,"iid   crowing  again>t    its  root.      The  operation  for  the  re- 

;i  tooth   was  a  serious  one.  and  followed  by  suppuration 

v-nial    incisions.     There    has    been    gradual    improvement 

I  r<  iin  the  effects  of  t  lie  opera  t  ion.      (  'hanue  of  climate  and 

'he  LM'tirrai   health  promi.-e  ;i   cure.      The  menopause  mav 

havi    had  -omethiim  In  do  with  the  neuralgia. 

AIH  i-lrative  case  is  the  one  shown  in  I;ig.  l>7.").      The  patient 


Tin;  .C-KAY  900 

is  himself  a  physician,  und  hud  suffered  for  some  your.-  from  pain  in  the 
upper  juw.  All  the  upper  teeth  hud  been  extruded,  und  at  various 
times  spicuke  of  bone  had  been  removed  from  the  maxilla.  He  con- 
tinued to  suffer  from  pain,  and  was  unable  to  wear  a  set  of  false  tooth 
for  more  than  an  hour  at  u  time.  The  r-ruy  examination  included  a 
number  of  radiographs  from  different  directions.  The  one  reproduced 
reveals  the  nature  of  the  case  dourly.  This  radiograph  was  made  with 
the  chiefly  affected  side  of  the  face  lying  upon  the  plate  und  with  the 
tube  over  the  opposite  side.  It  showed  un  area  of  opacity  where  the 
normal  transluconcy  of  the  ant  rum,  or  maxillary  sinus,  should  have 
been.  This  was  due  to  chronic  suppuration  in  the  ant  ruin,  which 
was  cured  by  an  operation  performed  by  Dr.  Cryer. 

An  .r-ruy  examination  in  un  obstinate  case  of  neuralgia  about  the 
face  should  exclude;  suppuration  or  polypoid  growth  in  the  untrnrn: 
cyst,  abscess,  or  tumor  of  the  maxilla;  retained  broken  roots  of  teeth; 
unerupted  teeth,  especially  third  molar  teeth;  und  the  different  lesions 
which  may  affect  the  root  or  the  root-canal  of  u  tooth  or  its  alveolus; 
and  the  presence  of  a  foreign  body,  such  as  a  broken  drill  or  a  part  of  a 
root-filling,  piercing  the  root  of  a  tooth  und  projecting  into  the  alveolus. 
The  inferior  dental  nerve  is  liable  to  compression  or  irritation  during 
its  passage;  through  its  bony  canal,  und  a  gooel  radiograph  of  this  part 
of  the  juw  is  often  of  the*  greate-st  value. 

Certain  intracruniul  conditions  would  bo  semght  when  the  clinical 
history  suggested  such  un  examination.  The  .r-ruy  reveals  the  presence 
of  tumor,  or  ubse-oss,  orhematemia  etf  the1  brain,  osseous  tumor,  sinusitis 
and  pachymeningitis.  Benedikt  has  especially  studied  the  radio- 
gruphic  appearance1  of  intrueTuniul  lesions. 

The  ,r-Ray  in  the  Diagnosis  of  Disease  of  the  Pneumatic  Sinuses 
of  the  Face. — The1  fluoroscope1  shows  the-  size-  und  shape1  of  the  different 
sinuses,  und  also  whether  they  form  the  normal  air  spaces  e>r  are  made 
more  opaque,  for  instance,  by  pus.  Such  an  examination,  however,  is 
not  dependent  upon  for  two  reusems:  the  .r-ruy  would  have  to  be  very 
perfectly  applied  to  produce  a  first-class  fluoroseopic  image'  and  an  ac- 
curate diagnosis  e>f  the1  frontal  sinus,  und  would  require  so  long  a  study 
as  to  bo  unsafe.  Some  ejpeM'utors,  however,  like  Culdwoll.  make  a 
very  brief  fluoroscopie-  examination  to  see  whether  everything  is  ad- 
justod  for  the  best  possible  radiograph.  This,  however,  is  undesirable 
unless  absolutely  nee-essury. 

Radiography  of  the  Frontal  Sinus.  The  radiograph  may  be 
made  rithor  from  a  late'ral  or  an  anteroposterior  direction. 

LnU'i'ul.  —The  plate  is  to  be  at  one  side  of  the  patient'.-  head  and  the1 
j-ray  tube  at  the  either,  the  normal  line1,  passing  through  the  frontal 
sinus. 

The  position  of  the  patient's  head  is  partly  a  matter  of  convenience. 
The  plate,  for  in-taiice,  may  be-  hori/ont  al,  and  the  patient  he  with  the 
of  his  face  resting  upon  it  (  Fi.u.  (>7t>).  Or  the  author's  lateral  plate- 
the  stereoscopic  plate-carrier  in  a  vertical  position, 
les  face  upward  with  I  he1  side1  <  >t  his  head  close  against 
This  apparatus  makes  it  easy  to  make  a  preliminary 
lation  in  exceptional  cast's,  and  makes  it  easier  tor 
the  operate)!1  to  protect  himself  from  the  .r-ruy  than  if  the  x-ray  tubf 
we're'  below  the  head  and  the  screen  held  over  it. 

The-  anticathoele  of  the  tube  should   be  at   a  eli-tance  of  30  inches 


MKDHAl,    KLKlTHK'lTY    AND    KOXTCKX    HAYS 

from  the  plate.  The  equivalent  spark  preferred  by  the  author  is 
.">  inche-.  (i")  kv..  MO  ma.,  for  four  seconds,  or  10  milliamperes  for  twelve 
>econd-  for  a  bill-pound  man,  using  an  intensifying  screen  (see  Exposure 
Table,  pa  lie  S'.Ul'. 

It  i-  very  convenient  to  have  the  tube  enveloped  in  a  localizing 
shield  which  limits  the  rays  to  the  required  direction,  and  which  the 
author  supplements  by  the  u.-e  of  a  sole-leather  or  aluminum  disk  to 
arre-t  t  he  soft  rays. 

The  indication-  to  be  gathered  from  a  lateral  radiograph  of  the 
frontal  -inns  relate  chiefly  to  its  condition  near  the  median  line  where 
it  i-  -een  in  profile.  It-  anteroposterior  and  vertical  measurements  are 
rendered  visible,  and  the  radiograph  shows  whether  this  part  of  the 
frontal  -inns  is  occupied  by  air  or  by  some  opaque  substance  like  pus. 


In  "!:••  of  the  author'-  radiograph-  i  Fiii.  (17  <     the  p<>-1erior  wall  of  the 
-inu-   -hows  irregular  -harp  bony  point-  and  the  infundibulum 

H-H. 

diouraph  o|  the  frontal  sinu-  i-  n-iially  -o  distinct   as  to 
ot  h  in  t  he  plate  and  in  a  print   m.-n  le  fn  nn  it . 
and    I'ancoa-t1    have    made    succe-slul    lateral    radiographs 
ot  her  pneumatic  -muse-  by   u-inir  a   hiuh  deuree  of 
• 

rail  ui/rn /ill*  ot   the  frontal  and  maxillary  sinuses  and 
\\ere,    1    believe,   fir.-t    siicecssfully   made   in    Killian's 
. 
I'  ''•'    •!  •  mull  i/iii/ilinii/in  <>,•  ,•/','-/</,/•  /',,/•  //,/.-,•  irarl'. 

•    V  •'  •. .  ha-  exhibited  man;,    pi  a  le>  of  excellent  antero- 


TIIK    .r-KAY 


971 


posterior  radiographs  of  the  frontal  sinus  made,  under  his  direction,  I 
believe,  by  Caldwell  and  others.1  Loeb,  of  St.  Louis,  has  also  done 
similar  work. 

The  radiograph  should  show  the  orbits,  the  nasal  bones,  turbinated 
bones,  traces  of  the  sagittal   suture  in  the  frontal  bone,  and  coronoicl 


suture.  The  size  and  shape  of  the  frontal  sinus  can  be  determined,  also 
the  position  of  the  septum  and  of  any  accessory  septa. 

CoakleyV  conclusions  are:  First,  it  is  possible  by  means  of  a  skia- 
graph to  determine  the  presence  or  absence  of  a  frontal  sinus  which 
extends  vertically  above  the  glabella  Second,  a  frontal  sinus  may  be 
small,  parallel  with  the  upper,  inner  manrin  of  the  orbit  and  not  detected 
in  the  skiagraph.  Third,  in  all  cases  of  unilateral  disease  of  the  frontal 
sinus  verified  by  operation  a  cloudines<  has  been  observed  in  part  or  all 
of  the  area  occupied  by  the  sinus,  and  an  indistinctness  in  the  outline 
of  the  cavity  as  compared  with  the  opposite  or  healthy  side. 

This  is  a  very  much  more  difficult  radiograph  to  make,  and  even 
the  most  expert  radiologist  may  expect  a  certain  number  of  complete 


072  MKDICAI.    KI.Kt  THU  MTV     AND    KONTt.KN    HAYS 

failures  before  acquiring  the  correct  tcchnic.     The  difficulty  lies  in  the 

fact  that  the  .r-ray  must  penetrate  the  entire  thickness  of  the  head  from 
behind  forward  sufficiently  to  act  upon  a  photographic  plate,  and  still 
be  capable  of  sufficient  selective  absorption  to  show  the  differences  in 
densitv  at  the  region  of  the  frontal  sinus. 

Some   plates   will   be   found    not    to   show   sufficient    effect  from   the 

.r-ray,  and  this  may  be  due  either  to  the  use  of  too  hi.u'h  a  decree  of 

vacuum  (the  rays  pa.-simr  ritrht  through  tin*  plate  without  chemic  effect), 

to  too  low  a  decree  of  vacuum  (the  ravs  all  being  absorbed  by  the  7  or  8 

inches  of  tissue),  or  bv  too  weak  an  intensity  or  too  short  an  exposure. 

<  >u  the  other  hand,  the  plate  may  show  sufficient   density,  but  in- 

sullicient   detail  everywhere.      This  condition  may  occur  with  a  long  or 

strong  exposure  to  a  ray  which  has  too  great  penetration  and  to  which 

[en>er  parts  of  the  head  are  almost   as  transparent   as  those  less 

dense. 

In  this  case  more  than  in  any  other  contrast  is  desirable  rather  than 
the  trreatest  detail. 

[;,  '«ti  •  Position*  of  the  Tube,  Plate,  ami  P,iticnCx  Head.— This  is  of 
the  greatest  importance.  The  tube  must,  of  course,  be  in  the  median 
line  at  the  back  of  the  head  and  the  plate  in  front. 

Many  radiographs  show  a  good  picture  of  the  aiitrum  and  ethmoid 

cells,  but  scarcely  anything  of  the  frontal  sinus.     This  maybe  due  to  the 

:,;'  •  that  the  tube  is  in  such  a  position  that  the  image  of  the  thickened 

::::;--  of  bone  at  the  occipital  protuberance  is  thrown  directly  upon  that 

of  the  frontal  sinus.      Other  radiographs  of   the   accessory  pneumatic 

-iii'i-es   of   the  face   have  the   image  of    the  ethmoid  cells  or   antrum 

ibsciired  by  the  shallow  of  the  petrous  portion  of  the  temporal  bone. 

Tii1'  .-hadow  of  the  horizontal  plate  of  the  frontal  bone  should  not  fall 

>--  t  he  orbit ,  bur  just  at  its  upper  border. 

i'he  -hadow  of  the  horizontal  plate  of  the  frontal  bone  should  not 
1  upon  that  of  the  frontal  sinus.     The  shadow  of  the  petrous  portion 
'  the  temporal  bone  should  not  fall  on  t  hat  of  the  antrum.  nor  that  of 
isillar  proce>>  of  the  occipital  bone  on  the  shadow  of  the  ethmoid 
il~.     There  i-  only  one  position  which  satisfactorily  avoids  all  defects: 
i     I-  patient's  forehead  and  nose  -hoiild  be  pressed  against  the  piate. 
[!><•  -hould  be  behind  the  head,  in  the  mei haii  line,  and  along  a  fine 
'    >•;;    the  glabella    (junction   of  nose  Mnd   forehead)    backward 
'•  '   in  the  skull,  which  i-  usually  to  be  f<>h   as  a  slight  de- 
i   1          ••;,'•-  above  the  occipital  protuberance. 

'  •    •  irection   has  also  been  described   M'aldwell)   as  alon.tr  a 
.•'••-   above   the   line  joining   ihe   u'lal<elia   and    the   external 


head    i-    pressed    againsl    the    plate    because   this 

''••I'  imaire  of  the  frontal  -inn-  than  if  the  plate  were  a  little 

fnun   the  fun-head,   a-   would   be   the  case  with   the  plate 

•  front   o)   the  tace  and  equidistant    from  the  mouth  and 

I  '  e   ;••   •  -.   it    will   be    noted,    a  re    Hoi     vci'tic!'!    to    the    plane   of 

•  a  decided  antrle. 

t  r.-iver-iiiii  the  entire  thickness  of  t):e  head,  consists 

elinu  in  st]-ainht    line-   from    the   anticathode   of   the 

'  cniir-e.  would  make  a  cl"ar  imau'e  if  the  plate 

''•a -otiable  distance,   but    there  are  al-o  -ecndarv   ra\'s 

.':;.    diredidii    frmn    the   various   point-   where   they 


arise.  The  finale  of  the  frontal  sinus  cast  by  ihc  direct  rays  mijiht  be 
clear  enough  if  the  plate  were  directly  in  contact  with  the  forehead, 
and  very  much  blurred  if  the  plate  were  at  a  distance. 

The  Position  of  lite  I'aticnt.  This  is  largely  a  matter  of  convenience, 
and  different  positions  will  be  found  desirable  under  different  circum- 
stances: 

(1)  The  patient  seated  with  the  chin  resting  on  the  table,  the  plate 
leaning  against  the  nose  and  forehead,  and  the  tube  behind  ( Fi^.  OS;->, 
pa»v977).  This  is  the  author's  usual  position.  Reid's  line  from  the 


• 


Fit:.  G7is.— liadiographv  of  ihc  frnntal  r-inus  with   the  patient  lying  fact-  down.      A  di 


phragm  or  cylinder  should  !«•  u>cd 


external  auditory  meatus   to  tlie  u'labella   is   horizontal  and  the  .r-ray 
tube  is  '2'.)  decrees  above  that   line. 

i '2 )  The  patient  Ivmu'  face  down  upon  the  plate;  the  tube  over  the 
back  of  the  head  <  Fiii.  t>~M.  Ileid'-  line  should  l>e  vertical  and  the  tube 
2o  decrees  above  it . 

•  J  The  patient  lyiim'  fact1  up:  the  tube  under  the  back  of  the  head; 
the  plate  over  the  face.  Reid's  line  should  be  vertical  and  the  tube  2:-! 
decrees  a! >•  ive  it . 

1  The  patient  lyin^  on  liis  siile  upon  the  author'-  lateral  ])!ate- 
holder,  which  hold-  the  plate  in  front  of  the  patient's  face;  the  tube 


971 


AND  KONTCKN   HAYS 


behind  the  head.      Heid's  line  should  be  used  as  a  guide  for  the  posi- 
tion of  the  plate  and  the  .r-ray  tutu-. 

The  N<r«m/  position  •.  Fig.  (ITS'  is  a  very  convenient  one,  as  all  it 
requires  is  that  the  patient  shall  eliinl)  upon  the  table  and  lie  face 
down.  It  doe-  not  permit  of  a  preliminary  Huoroscopic  examination  as 
do  the  others,  but  this  is  often  unnecessary  and  undesirable.  More 
than  half  of  the  author's  radiographs  of  the  frontal  sinus  were  formerly 
made  in  this  position. 

The  Jir*t  position  is  the  most  pleasant  one  for  the  patient,  but 
requires  that  the  table  shall  be  at  the  proper  height  or  that  some- 
thing shall  be  j)iled  uj)on  it.  There  is  also  more  danger  of  the  patient's 
moving.  The  last  difficulty  may  be  overcome  by  having  a  block  at  an 
adjustable  height,  which  the  patient  holds  tightly  between  his  teeth, 
and  which  i-  clamped  fast  to  the  table  or  to  the  plate-holder.  This 
position  enables  one  to  make  a  preliminary  fluoroscopic  examination  if 
necessary.  The  author  always  uses  it  in  the  ease  of  intelligent  patients. 
The  third  position  requires  a  special  table  or  canvas  stretcher,  so 
that  the  patient's  head  may  rest  upon  a  portion  transparent  to  the 
.r-ray.  The  .r-ray  tube  is  placed  under  this  part  of  the  table.  Those 
\vho  use  this  position  include  Cakhvell,  who  made  such  radiographs  ex- 
ceedingly well.  This  position  is  especially  adapted  to  the  preliminary 
use  of  the  fluoroscope  in  judging  the  radiographic  quality  of  the  ray. 

The  fluoroscopic  screen  is  laid  over  the  patient's  face  and  the  current 
turned  on  for  an  instant.  If  the  image  is  seen  to  be  a  good  one  the  cur- 
rent is  turned  off  and  a  photographic  plate  substituted  for  the  screen, 
the  current  then  being  turned  on  long  enough  to  produce  a  radiograph. 

The  most  extraordinary  precautions 
should  be  taken  to  shield  the  operator's 
face,  eyes,  hands,  and  genital  organs 
from  the  .r-ray  if  a  routine  use  is  made 
of  this  method. 

The  author'  considers  this  method 
altogether  too  hazardous  to  be  recom- 
mended, as  the  ray  that  is  required  is 
one  of  great  intensity  and  penetration, 
and  the  operator  has  to  stand  with  his 
whole  body  very  near  the  tube  while  he 
bend-  over  the  fhioroscope.  Modern 
apparatus  and  technic  make  this  entirely 
essa r\  . 


.\.,n 


ition   requires  the   au- 
-t  construction. 

in.    liT'J  .     This   consists   of  a 
!'  in  such  a  way  1  hat  1  hey 
it    cannot    open   more   than   'JO 
:i< !   re-t  iusj;  upon   t  he 
i  T<  •(  isci  >j  iic  ]  )late-holder 
by    the    vertical 
i     Fitr.  tiso  i.      If  a  pre- 
;   '  iS'J     i-   necessary,   the 
e    can    ever    tret     ill    flilol'o- 

ise    of    ni'otective 


tl 


TIIK    .T-RAY 


Care  should  bo  taken  that  the  median  piano  of  the  patient's  hoad  is 
horizontal.     A  little  pad  may  be  placed  under  the  side  of  the  neck. 


Fig.  GNO. — Radiography  of  tho  frontal  sinus,  employing  the  author's  lateral  plate-holder. 

As  the  antrvim  is  also  included  in  the  picture,  it  is  the  author's  custom 
to  have  the  patient  hold  a  cork  between  his  teeth.  The  landmarks 
of  the  upper  jaw  are  clearer  if  the  mouth  is  open. 


(ML:.    HM.    -  Fluoro.-i'opy   of   the    frontal    >imir-    pn-liininarv    to    rudiotrranhv    \\ith    tli 


Allusion    has    been    made    to    the    stereoscopic    plate-holder.      It    is 


eldom   necessary   in  make  a   stereoscopic   radiograph   in   frontal   -inn 


cases,  Ian    it   i-  sometimes  (.lesiraltle  t<»  change  the  plate  if  we  su<poc1 


MKDir.M.     KI.KrTKUITY    AND    KoNTCKN     KAYS 


that  the  patient  ha-  moved.  or  if  (he  tube  has  undergone  some  notable 
change,  or  simplv  if  one  wishes  to  take  two  separate  pictures  in  the  hope 
that  a  -I'mht  difference  in  all  the  conditions  will  result  in  one  picture 
beinii  better  than  (he  other.  The  stereoscopic  plate-holder  enables  one 
to  remove  the  first  plate  and  put  another  in  exactly  the  same  position 
without  moving  (he  patient  or  any  part  of  the  apparatus. 

The  author's  lateral  plate-holder  enables  one  to  dispense  with  a 
stereoscopic  plate-holder.  In  that  case  it  is  necessary  to  have  card- 
board or  paraffin  paper  over  the  regular  .r-ray  envelopes  to  protect  the 
plate^  from  (lie  moisture  of  the  breath  and  perspiration,  or,  better  still, 
to  have  the  plates  or  film  in  a  cassette,  and  as  an  intensifying  screen 
should  always  be  used  the  cassette  is  a  matter  of  course. 

Aut/mr'x  Dir/rt  fur  Positioning  tin  x-h'ai/  Tn(>c  for  Frontal  Sinus 
Rail/ii<i>-<i])hi/.  The  lube  is  in  a  protective  shield  provided  with  a  dia- 


f    fliinrosrnnic    examin;itioii    of    frontal 


-   to  the  operator.     iScr  tr\t   for  precaution 


ill 


m    which    may    be    made   as    small  -as    \]    inches   in    diameter.      A 

ha-  been  placed  upon  the  tube  after  trial  which  will  enable  us  to 

(he  lube  in   the  shield  so  that    the  focus  spot   on  the  anticathode 

e  exactly  oppo-ite  the  center  of    the  diaphragm.     A   mark  upon 

ut-ide  of  the  -hield  indicates  the  position  of  the  focus  spot,  and  a 

-;i'  lni'j.  Iron;  tin-  -pot    is  parallel  with  the  central  ./'-ray.      A  spring 

measure  fastened  at    that  spot  enables  one  to  place  the  tube  so  that 

'•ified   object,  in    this  case  the  glabella,    is   in    the   direction   of  the 

:  ra  \   an<  I  at  a  di-1  aiice  of  i  50  inches  from  t  he  ant  icat  hode. 

ifijeil   in  the  axis  <>f  tube  -hield   i-  a   clinometer,  or  measurer  of 

.  made   from    ;i    dock    dial    with   a    -ingle    hand    freelv    pivoted 

.    uei»hled.       If  the  hand  i-  at    (i   o'clock    when    the  long   axis 

vertical    and    the   central    ray    hori/ontal,    then    the 

ul    •'•'.    time    minute-    from    1  he    (i    o'clock    mark 

the  cent  r;  1  1  ra  v  i-  inehned  at  an  angle  of  about  '2'-\  decrees. 


i  I;K  .r-KAV 


Fiii.   GS4. — Author'-   frame  applied    to  the   head   to  indicate  the  median   plane  for  sinu 


••iX  MKiurAi.   i:i.i:n  KHITY   AND  KONT<;KN   HAYS 

The  technic  is  to  place  the  patient's  head  in  the  right  position, 
fasten  the  tube  at  the  proper  angle  of  inclination,  adjust  the  height  and 
distance  of  the  .r-ray  tube,  making  use  of  tape  measure,  as  in  Fig.  683. 
When  a  woman'.-  face  i.-  against  the  plate  her  hair  often  makes  it 
difficult  to  see  jn.-t  \\here  the  median  or  sagittal  plane  is.  The  author's 
whalebone  frame  previously  applied  to  the  head  facilitates  this. 

Tin  l)/x(<inc>.  front  //n  Tulu  to  (he  J'late.—  The  selection  of  the  distance 
is  influenced  by  two  considerations:  first,  that  a  short  distance  will  give 
a  better  picture  and  in  a  shorter  time  than  a  long  distance;  and,  second, 
that  too  close  proximity  to  the  back  of  the  head  with  so  long  and  strong 
an  exposure  may  produce  alopecia  or  dermatitis—  30  inches  is  the 
author's  recommendation. 

( 'aldwelP  u>ed  at  one  time  a  distance  of  IX  inches  from  anticathode 
to  plate  and  all  exposure  of  twenty  seconds.  His  article  did  not  state 
what  interrupter  he  used,  but  it  is  supposed  to  be  a  ('aldwell.  "With  a 
certain  interrupter  and  coil,  with  the  rheostat  resistance  all  out,  a  reading 
of  10  milliamperes  shows  that  the  penetration  of  the  tube  is  about  high 
eiioiiizh"  i  (  'aldwell  I. 

Tin  Ti cbnic  of  the  Exposure. — These  pictures  present  such  difficulty 
that  the  author  will  repeat  here  some  of  the  general  details  as  to 
technic  which  have  already  been  described  elsewhere. 

With  a  12-inch  induction-coil  with  a  ('aldwell  or  a  Wehnelt  in- 
terrupter, and  a  rheostat  in  which  the  resistance  is  afforded  by  different 
strips  of  metal,  the  interrupter  is  regulated  to  give  a  current  of  11 
ampere-  with  the  ('aldwell  or  If)  to  22  amperes  with  the  Wehnelt  inter- 
rupter, and  some  resistance  is  used  while  the  vacuum  of  the  .r-ray  tube 
i-  regulated  to  the  proper  degree.  This  should  be  such  a  degree  that 
with  all  the  rheostat  resistance  cut  out  the  tube  will  back  up  a  parallel 
.-park  of  f)  inches.  The  milliamperemeter  should  indicate  the  pas- 
sage  of  x  or  10  milliamperes  of  secondary  current  through  the  tube. 
The  penetration  of  the  ray  .-hould  be  about  X  Benoist. 

The  use  of  an  unfluctuating  converter  or  of  a  transformer  and  the 
( 'oolid^-e  Kadiator  tube  permits  of  a  current  of  about  (If), 000  volts  and 
about  30  milliamperes  as  the  best  routine  factor.-  for  this  work. 
The  tube  should  have  a  penetration  of  \o.  (>  or  <V  Benoist. 
'/''«    /><'//, /,/Y/,ym.-  This  is  absolutely  essential  with  a  gas-filled  tube; 
-1   results  are  obtained  with  an  orifice  1 '   inches  in  diameter.     A 
'  'hragm  may  be  used  or  t  he  ant  hor's contact  diaphragm  (p.  801). 
•'<    -hould  be  rapid  and  have  good  density.     Such  a  plate  as 
.••-ray  plate  i-  suitable.      Or  such   a    film   as   the   Kastman  du- 
•-ray  film.      The  Paragon  screen  plate  gives  good  results  with  an 
in  srjven  if  care  is  taken  to  avoid  overexposure.     An  intensify - 
•11  -hould  always  be  used. 

the  absence  of  secondary  radiation  from  the  gla-s  wall  of  the 
'  ibe    makes    a    -mall    diaphragm    unnecessary.     The    author 
with   it    bccau-e  of  the  increa.-ed  difficulty. of  posit  ion- 
vtube.      And  in  many  radiographs  embracing  the  entire  head 
''ii  of  the  frontal  -inu-  ha-  been  -o  good  as  to  make  it  appear 
iry  rays  from  the  ti--ue-  of  i  he   head   were  not  a  mate- 

lor  with  a  (  'o( ilidu'e  1  ube. 

/.<,">.  'in  .      Thi-  varie.-  from  a   traction  of  a  second  to 
online  to  the  apparatus  and  the  quantity  of 


Tin:  .r-u.\Y  079 

power  employed.  Six  and  a  half  seconds  would  lie  correct  with  5- 
inch  spark,  '.'>()  milliamperes,  oO  inches,  man  weighing  loO  pounds. 

It  would  he  a  very  serious  mistake  for  an  operator  with  a  powerful 
apparatus  to  try  to  overcome  errors  in  technic  or  relative  position  by 
giving  long  exposures.  There  would  be  danger  of  dermal  it  is  or  alopecia. 

The  plate  shows  very  much  better  than  the  print  in  all  radiographs  of 
the  accessory  pneumatic  sinuses  taken  in  an  anteroposterior  direction. 
It  is  to  be  examined  in  a  perfectly  dark  room  by  means  of  a  negative 
examining  box.  The  latter  has  a  framework  which  receives  the  plate, 
behind  which  is  a  sheet  of  opal  glass  lighted  by  a  number  of  incandescent 
lamps.  The  degree  of  illumination  is  regulated  by  a  rheostat.  The 
most  brilliant  light  does  not  always  show  the  picture  to  the  greatest 
advantage. 

In  the  absence  of  a  negative  examining  box  such  a  plate  may  be 
studied  in  a  darkened  room.  The  plate  is  held  up  between  the  observer 
and  a  sheet  of  white  paper,  upon  which  a  fairly  brilliant  light  is  thrown. 
These  plates  are  usually  not  strong  enough  to  show  well  if  held  up  in 
front  of  an  ordinary  electric  light. 

The  plate  may  be  treated,  as  suggested  by  Caldwcll,  to  accentuate 
the  important  portion  of  the  image.  A  square  of  sheet  lead,  together 
with  lead  numbers  and  lead  letters  spelling  the  words  riyht  and  left, 
is  placed  over  the  central  part  of  the  plate  after  the  exposure  is  com- 
plete and  the  plate  removed  from  the  patient.  A  convenient  plan  is  to 
have  all  these  permanently  mounted  on  a  cardboard  XX  10  inches, 
and  simply  have  to  change  the  serial  number  of  the  plate  each  time. 
This  contrivance  being  in  place,  a  short  st  rong  exposure  of  a  few  seconds 
is  made.  As  the  plate  is  being  developed  t  his  full}'  exposed  border  comes 
up  and  materially  assists  in  the  observation  of  the  process  of  develop- 
ment by  the  ruby  light  in  the  dark  room.  The  dense  black  border 
produce*  1  on  the  finished  plate  brings  out  the  useful  part  of  the  image 
more  clearly  when  the  plate  is  examined  by  transmitted  light. 

A  radiograph  of  a  probe  in  the  frontal  sinus  is  considered  by  Douglass 
the  only  certain  proof  of  its  entry  into  the  sinus.1 

A  metal  tube  passed  up  through  the  infundibulum  has  shown  very 
well  in  a  lateral  radiograph  by  the  author;  not  quite  so  well  in  an  antero- 
posterior one. 

Jack,  at  the  time  of  reading  his  article,2  regarded  the  value  of  the: 
.r-ray  in  frontal  sinus  diagnosis  as  still  xnl>  ji«/icc.  Radiographs  made 
for  him  had  not  proved  successful. 

Mosher'  reports  the  successful  employment  of  the  radiographic 
method  of  examination  in  sinus  disease. 

llarland  and  Pancoast  believed,  at  the  time  of  reading  their  report 
at  the  Annual  Meeting  of  the  Medical  Society  of  the  State  of  Pennsyl- 
vania. Sept.,  IHOli,  that  a  high  degree  of  vacuum  and  very  great  electric 
power  were  required.  The}"  used  all  UK  luct  ion-coil  with  (iO  amperes  ot 
current  through  the  primal'}-  coil,  a  distance  of  Hi  inches  from  the  anti- 
cathode  to  the  plate,  and  an  exposure  of  ten  to  twenty  seconds.  'J  Ins 
is  a  1  remendouslv  powerful  current .  The}'  made  their  pictures  with  the 
tube  belo\v  the  level  of  the  occiput.  The}'  used  a  diaphragm. 

(Tver's  dissections  of  the  frontal  sinus"1  show  a  very  great  diversity 


i:i.!:rn;i(  ITY  AND  HOXTCKN   RAYS 


outlet-.      Such    variation-    \vnul<l    be   discovcralile   l>y   anteropostorior 
radiograph. 

I-'iu'iirc<  tis.")  and  fiSti  show  variation-  in  the  noi'inal  appearance  in 


•  •  '•  - 


981 


n 


Transillumi  nation  of  the  Frontal  Shuts. —  This  must  be  done  in  a  very 
dark  room.  A  3  candle-power  incandescent  lamp  is  enclosed  in  an 
opaque  cylinder,  whose  open  end  is  pressed  close  against  the  under 
surface1  of  (he  upper  wall  of  the  orbit.  A  red  glow  may  be  seen  defining 
the  extent  of  the  frontal  sinus.  The  glow  may  be  lessened  when  the 
sinus  is  filled  with  solid  or  liquid  substances  instead  of  air.  The  diag- 
nostic value  of  the  method  is  impaired  by  the  fact  that  some  sinuses,  con- 
taining pus  or  swollen  or  polypoid  mucous  mem- 
brane, show  apparently  normal  illumination,  and 
others,  which  are  perfectly  normal,  do  not  illuminate 
as  well  as  usually.  Sometimes  in  a  normal  case  the 
two  sides  show  unequal  illumination. 

Radiography  of  the  Antrum  or  Superior  Maxil- 
lary Sinus.-  r[  his  accessory  pneumatic  sinus  may 
be  examined  by  the  .r-ray.  either  fluoroscopically  or 
radiographically,  from  several  different  directions. 

(1.)  The  tube  may  be  at  the  affected  side1  of  the 
face,  and  the  fluoroscope  or  photographic  film  may 
be  held  inside1  the1  mouth,  either  in  a  horizontal  posi- 
tion or  applied  as  closely  as  possible1  to  the  inner 
surface  of  the1  gums  and  roof  of  the1  mouth.  The 
image  shows  whether  the  antrum  is  of  normal  size, 
whetheT  it  is  rilled  with  pus,  polypoid,  or  tumor 
tissue',  and  whether  any  of  the1  teeth  projee-t  into  it 
and  cause1  trouble1.  The  details  of  this  examination 
are1  explained  in  the  scctiem  on  .r-Kay  in  Dentistry. 

(2)  The1  tube  may  be1  at  the  opposite  side1  of  the 
face,  the1  mouth  open,  and  the  ray  shining  through 
the1  mouth  from  below  the  level  of  the  opposite  teeth, 
and  having  to  penetrate  only  the  roof  of  the  mouth 
and  the1  upper  jaw  on  the1  affect  eel  siele1.     The  fluoro- 
scope1  or  photographic  plate1  is  held  against  the1  outside 
of  the1  fae'e1  on  the1  affected  siele1.     A  comparison  be1- 
txvee1!!   the1  two  antra   may  be  thus  obtaine'el.     The 
quality  of  the1  ray  required  is  about  Xo.  (>  Benoist. 
A  much  greater  degree  of  penetration  does  not  afford 
sufficient  shadow  to  even  make1  out  the1  roots  of  the 
teeth  clearly  with  the1  fluoroscope;  4-inch  spark,  30 
ma..  23-inch  distance1,  no  intensifying  sciven  would 
require  abend  five1  seconds  for  a  150-pound  man. 

(3)  The1  tube  may  be  at  the'  oppeisite  side1  of  the 
face1,  in  a' line  passing  through  both  antra  from  siele 
to  siele.     The  plate  is  against  the  affected  side  of  the 
face.    This  position  is  ve'rv  easilv  maintained  bv  the 


patient  if  he  lie 
the1  aftecte'd  siele' 
distance1   should 
30  ma.,   for  four 
150-pound   man 

SIX')!. 

Figure  liSS  shows  the  ant  rum  forming  the1  natural  air  space  above 
tin1  level  of  the  hard  palate1  and  crossed  vertically  by  the  malar  promi- 
nenco. 


n  the  table  with  the  plate  under 

f  the  face  and  the  tube  over  the  opposite  side.      The 

e   about    30   indies,    the    -park    equivalent    5    inches. 

econds  or  any   other   120  ma.  second   exposure  for  a 

ith  an   intensifying   screen   (see  Exposure  Table,    p. 


i,   Ki.KiTiuriTY   AND   UONTCKN   HAYS 


I'iir.  liss.  —  Normal  antruir, 


THE    .T-RAY 


OSS 


Figure  689  enabled  the  author  to  make1  a  diagnosis  of  suppuration  in 

the  aiitruin.     The  case  is  further  figured  on  p.  (.)S1. 

A  radiograph  made  in  this  position  does  not  give  a  comparative 
picture  of  the  two  sides.  An  important  fact  is  that  the  shadow  of  an 
opaque  substance  in  either  antrum  would  he  cast  upon  the  plate,  no 
matter  whether  it  was  on  the  side  next  to  the  plate  or  not.  Generally 
it  is  only  one  side  that  is  affected  and  no  doubt  exists  as  to  which  side. 
The  shadow  of  the  opposite  ant  rum  if  normal  offers  no  real  difficulty, 
even  though  it  is  superimposed  on  the  image  of  the  affected  side.  The 
hitter  is  dearer  and  of  the  natural  si/e,  while  the  former  is  enlarged  and 
vague  because  of  its  distance  from  the  plate.  It  is  to  secure  the  last  con- 
dition that  the  tube  is  placed  as  does  as  practicable  to  the  unaffected 
side  of  the  face.  Figure  090  is  such  a  radiograph  of  the  antrum  in  an 


Fiji.  690. — Normal  antrum  in  empty  skull  (filled  with  shut  on  one  side). 

empty  skull.  Placing  the  re-ray  tube  somewhat  further  back  enables  us 
to  secure  separate  images  of  the  two  antra  in  a  lateral  radiograph. 

Cases  occur  in  which  it  is  necessary  to  make  a  comparative  picture 
of  the  two  antra,  and  then  the  following  method  is  generally  used: 

(4)  The  tube  is  behind  the  patient's  head  and  in  the  median  line, 
the  plate  being  in  front.  The  relative  position  recommended  for  ex- 
amination of  the  frontal  sinus  answers  very  well  for  the  antra.  The 
frontal  sinus,  ethmoid  cells,  and  both  antra  often  show  very  well  on  the 
same  plate.  The  antra  alone  are  somewhat  better  shown  in  a  radio- 
graph made  with  the  chin  somewhat  flexed  toward  the  chest  and  with 
the  tube  at  such  a  level  that  the  shadow  of  the  occiput  falls  above1  the 
antrum.  The  antra  show  better  when  the  tip  of  the  nose  is  pressed 
right  against  the  plate  than  when  the  forehead  touches  the  plate. 

Tliis  position  may  be  obtained  in  any  of  the  ways  mentioned  on 
pages  973  to  97t>  in  describing  anteroposterior  radiography  of  the  frontal 


'.»S4 


MF.im'AL    KLKiTKHlTY    AND    Iii)NTGEN    HAYS 


..inns.     One  of  the  best  hchm  with  the  author's  lateral  plate-holder,  the 
patient  lyiniron  hi-  side:  and  the  other  with  the  patient  lying  face  down 

upon  the  plate. 

Tliis  picture  i-  less  difficult  than  the  anteropostenor  one  ot  the 
fiontal  sinus,  hut  at  the  same  time  is  far  from  easy.  At  a  distance  of 
Winches,  l-im-h  spark  e(|uivalent,  oOma.  for  four  seconds  with  an  intensi- 
fviim  screen,  <>r  any  other  1'JO  ma.'  -econd  e:<i)osure  would  be  correct 
i'i  ir  :t  l.")i)-pi  unul  man. 

Kio-iire  li'.M  shows  a  case  of  long-standing  suppuration  in  the  ant  rum; 
!  he  -aine  patient  a-  Fi'i.  t'>sl.(. 


\''rin:il  fniiiKil  -iiiii-:  '-  und  "',  normal  ethmoid 


Radiography  of  the  Ethmoid  Cells.— The  ethmoid  cells  lie  between 

•     r  wall     of  1  he  l  \v<  >  orbit  -  and  t  he  upper  part  -  of  t  he  na-al  fos-a'. 

•    ethmoid   cells  -how  in   either  an   anteroposterior  or  a 

The  po-terior  ethmoid  cell-  ean   be  -tudied  be.-t   in 

[•"mure-  o'.rj   and   o'.Kl   -how   the   po.-ition   of  the 

'••  hmo  -  in  an  empty  -kull. 

examination    i-   made   u:;h    the   plate   in    trout. 

e  In  ad.  and  may  be  above  the  occiput  at   the  same 

•    t  hi     frontal   -inn-   or   beli  iw   t  he  level  <  if  t  he 

'   '  •  t  ion-  for  t  lie  ann-um,      The  rh<  lice  of  p<  >-i- 

'  •   -; .'   :    the   in1/'  ih  i  'nii-lil    i-   -Uppo-ed   to  extend   to 


THK    .r-KAY 


Fit:.  O'.»L>.— Middle  ethmoid  eell<  full  of  lead.      Lateral 

. 

/;S:-  /  ••-*?. 


I'iL'.  H'.I:;.  -M:  Mli'  eimnoid    cell-    fi;ll    nf   1.    id.      Frontal  -'•  u-   :u  i]  iintniin   In  natural  con 


<»Sti 


Mi:iM(    \l.     KI.K<  TRU'lTY    AND    HONTCKN    KAYS 


the  frontal  -inus  in-  to  the  anti-inn.  The  technic  is  the  same  as  for  the 
autcropostrrior  radiograph  of  the  frontal  sinus. 

Figure  <i*)-l  is  a  radiograph  of  a  youi)»-  lady  with  lonii  chronic  sup- 
puration in  the  antruin  ami  ethmoid  cells,  as  evidenced  by  the  dark 
t  ract  on  one  side. 

Tin1  lateral  view  of  the  anterior  or  posterior  ethmoid  cells  is  not 
a  diflicult  radiograph  to  make.  The  patient  may  lie  with  the  affected 
side  of  hi-  face  res ti nil1  upon  the  plate.  The  tube  is  over  the  other  side, 
at  a  di.-tanee  of  )•>()  inches  from  the  anticathode  to  the  plate.  Five- 
inch  spark.  (')")  kv.,  oO  ma.,  four  seconds,  or  any  other  120  ma.  second 
expo-tire  for  a  150-pound  man. 


I        '  ' '  i       ( '1  ironic  Mippurat  ion  in  ant  rum  and  otnmoi 


iput .      1  his  is  practicable  only  for  the  antruin. 


Radiography  of  the  Sphenoid  Cells.     These  are  studied  in  a  lateral 
radiograph  made  in  the  same  manner  as  that   of  the  ethmoid  cells. 

Figures   ti!'."  and   (>(.K>  are  radiographs  made  of  the  sphenoid  cells  in 
an   empty   -kiill.      They  show   the   relation   of  these   cells  to  the  normal 
and  -hadows  of  the  adjacent  parts.      Tliey  havi1  served  the  author 
i  na  1 1  in MC  charts. 

In    a    radiograph   of  an   actual   patient    a   certain   dark   shadow   was 

n  correspond   \\itli  a   natural   bony  shadow  in  the  chart   and  not 

po-ition    of   the   air-space   forming   the   sphenoid   sinus.     The 

\va-  thai   thi-  -inns  was  not   filled  with  pus. 

i  if  tin   ,•  jiln  nniil  shows  beautifully  in  a  case  now  under  treat- 

.  cross-fire.      The  siti'lit  of  one  eye  had  been  lost  before, 

thf   .--.  •   :  in.      The   tumor   now   seem.-  somewhat   smaller  and 


Til  10    X-RAY 


087 


the    vision    in    the    other   eye    which    was   badly  impaired   has   become 
normal. 

Finn/  in  the  Sphenoid  Cell*.  Previous  radiographs  h;id  failed  1o 
show  any  abnormality  in  spite  of  the  fact  that  a  cupful  of  fluid  ran  from 
the  nose  in  five1  minutes.  The  author  had  the  patient  hold  her  head 
perfectly  upright  for  half  an  hour,  a  sufficient  length  of  time  to  ensure  the 
sphenoid  cells  beiii"'  full  and,  without  change  of  position,  made  radio- 
graphs lateral  and  anteroposterior.  The  former  especially  showed  an 
opaque  mass  instead  of  the  air  space  of  the  sphenoid  cells.  The  fluid 
was  eerebrospinal  fluid  and  the  patient  died  of  meningitis. 


Stereoscopic  Radiographs  of  the  Pneumatic  Sinuses  of  the  Face.— 
Stereoscopic  radiographs  of  the  sinuses  may  be  made  by  havintr  the 
tube  1?,  inches  to  one  side  of  the  median  line  for  the  first  plate,  and 
the  same  distance  to  the  other  side  for  the  second  plate. 

The  anteroposterior  radiographs  of  the  frontal  sinus  require  so  lonjr 
and  strong  an  exposure  that  the  double  length  of  exposure1  required  for 
stereodiaiiTaphy  is  usually  undesirable. 

There  is  not  the  same  objection  to  the  stereoscopic  method  in  lateral 
radiographs  of  the  frontal  sinus,  the  ethmoid  cells,  and  the  antrum. 

The  Turbinated  Bones  and  Septum  Nasi.  The  turbinates  show  in 
any  of  the  anteroposterior  radiographs  of  i  he  face.  Their  si/e  and  shape 
are  shown  and  the  extent,  Lo  which  I  hey  encroach  upon  the  nasal  pas- 


MKDU'AL    ELECTRICITY    AND    KONTGKN    KAYS 


>ages.     Deviations  or  old  or  recent  fractures  of  the  septum  are  well 
shown. 

Topography  of  the  Pneumatic  Sinuses  of  the  Face  as  Shown  in 
Radiographs.  —  The  author  exhibited  at  a  meeting  of  the  Rhinological 
and  Laryngological  Section  of  the  X.  Y.  Academy  of  Medicine,  Novem- 
ber. 11H)7.  a  series  of  radiographs  of  an  empty  skull  in  which  one  or 
oilier  of  the  >inu>e>  \va-  lilled  with  lead  shot.  The  radiographs  were 
made  in  either  ;•  lateral  or  an  anteroposterior  direction  and  some  of  them 
•were  stereoscopic.  The  value  of  such  pictures  lies  in  the  guide  which 


'hey   atlord   to  Mie    recognition    oi    the  dilteren!    Amuses  in   radiographs 

lll.'lde    ffl  Mil    :icl  I);,  1    j  i;|  1  jellt  S. 

Some  of  i  he-e  r;tdio<_M'a  phs  are  reproduced  in   Fig>.  W2,  ti'.'M,  (i!).").  and 

1 1 ' >  1 1 

THH  NETK 

•   e\;iniiii.'ii  ion   of   the   neck    i-   rather  inconvenient.  i>uf 
ii'e-ence  iii    loreiii'ii  liodie<  or  lunior^.      Fractures  ot 

<•• '  i  K  i!<  'iile    ch;inij.e>    in     tlie     |;ir\'HX    are    much    lietler 
'!.       i  hei'e   i.-  a  ca.-e  on  record  of  tlie  imaiie  of 


THE    X-RAY 


089 


the  cartilages  of  the  larynx  being  mistaken  lot1  a  set  of  false  teeth  — 
operation,  death,  teeth  not  found  in  the  patient'.-  throat,  hut  subse- 
quently discovered  in  his  bed. 

Lateral   Radiography    of   the    Neck.-  In    radiographing    the    neck 
from  the  side  the  patient    i-  -itting  up,  the  plate  i-  at   one  -ide  of  the 


what  elevated,  so  that  the  body  of  the  jaw  is  horixontal.  The  tube  i- 
on  the  opposite  side,  at  a  distance  of  '2-\  inches  from  the  ant  icat  hode 
to  the  plate,  and  about  \  inch  below  the  level  of  the  chin.  The  resist- 
ance may  be  4  inches.  .V>  kv.,  o()  ma.,  twelve  -econd>  without  an  in- 
tensifying screen,  or  10  ma.,  thirty-six  seconds,  for  n  150-pound  man  'see 
Kxposure  Table,  page  SOl)).  It  may  very  well  be  found  that  the  plate 


1 


pj,_r.  007 — Lateral  r;i<lio<irnph  nf  fho  neck. 

will  -how  details  which  it  will  be  difficult  to  bring  out  in  the  print. 
The  picture  shows  the  lower  jaw.  the  tongue,  the  esophagus  and 
pharynx,  the  hyoid  bone,  the  cartilage-  of  the  larynx  the  cervical 
vertebra1,  and  -otnetinie-  the  styloid  |)rocess  of  the  tem]>oral  bone. 
An  unusual  amount  <>f  ossification  in  the  thyroid  cartilage  i-  said  to  have 
caused  it  to  be  mi-taken  for  a  set  of  fal-e  teeth  in  the  case  referred  to 
aljove. 

Broken  Neck  from  Diving.-  One  case  with  paraplegia,  examined 
by  the  author  for  Or-.  Howell  and  Front,  -howed  in  the  lateral  radio- 
uraph  a  frarture  of  the  fourth  cervical  vertebra  and  a  dislocation  tor- 
ward  of  the  fifth.  Tin1  anteroposterior  view  wa-  not  of  much  >ervice. 
Recovery  followed  manipulative  replacement  and  immobilization. 


MKDICAI. 


TKKITY   AND  H<")XT(;KN  IL\YS 


Another  ca-e  showed  no  displnoomonl  MIK!  death  occurred  many  months 
later. 

An  anteroposterior  radiograph  of  the  neck  is  mad"  with  the  patient 
lyiim-  fare  up  on  the  table,  with  the  plate  under  the  hack  of  the  neck, 
and  the  tulie  vrrti'-dly  over  the  cricoid  cartilage.  '1'lie  distance  is 
'2-\  mrhe<  Jrom  the  anticathode  to  the  plate  and  the  exposure  the  same 
as  for  the  anteroposterior  radiograph,  Figure  (>(.)8  is  of  a  patient  whose 
larynx  had  lu-en  removed  for  carcinoma:  the  tracheotomy  tube  is 
<hi  >wn. 

Cervical  Ribs.     The  anteroposterior  position  i>  the  correct  one  for 


ntfln-'itiiniy  tulic  in  position  after 


or  tiii-  condition.     The  distinctive  appeai'ance  in  this 

,   h  ;i  Hipeniumerarv  ri'h  iloe.-  not  extend  around  to 

.i  <•:..  li  .'   form.-  a  short   -irai^ht   lione.      A  -nod  raih.o- 

;i1e    ;i    ci  :  \  U'al    I'll)    \}'<  i!n     1  he    t  I'ali-ver-C 

I'll!':,.      \\herc  it    is  quite   rudimentary,  however,   it   is 
f  •  he  symptoms  <-om]  of. 

ft  ni  1  lilat  era!,  ari     •    M  rom  1  he  seventh  cervi- 

•  ,  mei'a  ry  nl  >  may  1  »•  more  <  leveloped  than 

•  •  idiment  a  !••-,   ( •    ;  I-  <  -i  'lit  any  form  bet  ween 
rili.      The  et'leH  •  ~i  'I'ii  ins  \\  hrn  the  • 


TIIK    .f-KAY  901 

and  nerves  pass  over  it.  The  symptoms  as  summarized  by  Keen'  are: 
1,  There  may  be  a  hard  tumor  in  the  neck  with  a  high  and  obliquely 
pulsating  subclavian  artery:  2,  there  may  be  severe  neuralgic  pain,  per- 
verted sensation,  and  hoarseness:  '.*>,  there  may  be  thrombosis  in  the 
subclavian  artery,  gangrene  and  edema  of  the  extremity,  and  a  sug- 
gestion of  aneurysm;  4.  there  may  be  wasting  of  the  muscles  of  the  arm, 
dysphagia,  and  scoliosis. 

Rotary  Dislocation  of  the  Atlas.-  This  comparatively  rare,  but  not 
necessarily  fatal  injury  may  be  diagnosticated  by  a  lateral  radiograph 
of  the  neck.- 

Forward  Dislocation  of  the  Atlas. — Forward  dislocation  of  the 
atlas  with  fracture  of  the  odontoid  process  of  the  axis  is  the  lesion 
which  the  legal  hangman  aims  to  product1,  and  which  usually  occa- 
sions such  compression  or  laceration  of  the  spinal  cord  as  to  cause 
practically  instant  death.  A  lateral  radiograph  of  the  neck  demon- 
strates it.3 

Fracture  of  the  Cervical  Vertebras. — This  will  show  in  an  antero- 
posterior  radiograph,  but  a  lateral  one  will  usually  be  found  more 
desirable. 

Localization  of  Foreign  Bodies  in  the  Tissues  of  the  Neck. — 
Stereoscopic  radiography,  either  lateral  or  anteroposterior,  gives  in- 
teresting results  in  localizing  such  foreign  bodies  as  bullets. 

Localization  on  the  McKenzie-Davidson  principle  is  valuable  in  the 
same  class  of  cases. 

It  is  much  simpler,  however,  to  take  two  radiographs  of  this  region 
at  a  right  angle,  first  fastening  a  lead  marker  on  a  part  of  the  neck  where 
its  image  will  not  cover  that  of  the  bullet  which  is  located  in  this  way. 
The  same  thing  may  be  accomplished  with  the  fluoroscope.  The  neck 
is  examined  at  first  from  the  side,  and  a  lead  marker  is  applied  at  each 
side  of  the  neck  in  a  direct  line  with  the  bullet,  as  seen  in  the  fluoro- 
scope. Then  the  fluoroscope  is  held  behind  the  neck  and  the  tube  in 
front  while  another  pair  of  markers  are  applied.  The  intersection  of 
these  two  lines  is  readily  found  by  the  surgeon  if  the  different  marks 
are  made  durable  by  nitrate  of  silver. 

Localization  of  Foreign  Bodies  in  the  Esophagus. — These  are 
very  apt  to  be  metallic,  and  if  of  considerable  size,  like1  a  e-oin,  should 
be  easily  located  in  any  part  of  the  esophagus.  One1  glance1  at  the 
fluoroscope  will  generally  reveal  tin1  presence  and  position  of  the  for- 
eign body.  This  was  the1  case  in  the  author's  own  patient,  whose 
radiograph  (Fig.  (>99)was  taken  simply  as  a  record.  The-  nickel  five- 
e-e-nt  piere1  was  removed  by  a  coin-catcher  passed  down  through  the 
mouth  withemt  waiting  for  the1  photographic  plate1  to  be1  elevelope'd.  A 
good  deal  of  twisting  and  pulling  was  required  in  this  case,  as  the-  coin 
had  been  in  position  for  nine  days  and  had  begun  to  ule-erate  through  the 
wail  of  the  esophagus.  The1  utmost  gentleness  had  to  be'  used  in  the-se1 
manipulations,  and  it  required  five1  minutes  to  remove1  it  after  it  was 
en i:\-igi-d  in  the  coin-catcher.  This  instrument,  it  will  be  remembered,  is 
a  sort  of  blunt  hook  hinge'd  upon  a  flexible  handle,  and  is  passed  beyond 
the  coin  and  then  withdrawn.  When  it  engages  the  coin,  the  latter  is 
brought  out  by  pressure  applied  ;,i  its  most  distal  part,  and  the1  coin 

1  Amor.  Jour.  Me.i.  Sciences,  Feb.,  1'.«>7. 
-Corner,  Annul- of  Surgery,  .Ian..  I'.'OT. 
:i  I\cllv,  Ilii,!..  Auiru-t.  1 '.'<>'">. 


MKDICAL    KLKiTKICITY    AM)    RONTOEN    RAYS 

may  tip  in  one  direction  and  tear  the  wall  of  the  esophagus  if  it  catches 
in  a  depression  caused  by  ulceration.  Such  an  accident  is  to  be  avoided 
by  livntleness  and  by  twisting  and  turnin».  If  the  coin  refuses  to  move 
the  coin-catcher  should  be  freed  from  it  by  pushiim  it  back  and  then 


lunimti  n    into  a   po-ition  in  which  it   -lip-  pa-t    the  coin  and  out   o!   the 
pat  lent  's  inoiit  h. 

The    ne\t    -tcp    in    -udi    ;i    c-.i-^c    would    be    one    \\lnrli    |]i|u-|it    liaVC    beet) 

u-ed    in    the    bemnnmji      extraction    by    torcep.-    under    liuoi'oscopic    ob- 
servat  ion. 


The  position  of  the  coin  is  first  ascertained  by  the  fluoroscope  and 
the  esophaiieal  forceps  arc  then  introduced.  Ay;ain  the  fiuoroscope 
is  used,  and  the  coin  sei/ed  Ii\-  the  l>|;ules  of  the  foivep-  under  (lirect 
observation.  Traction  is  then  made,  and  as  it  i-  exerted  upon  t!ie 
proximal  part  of  the  com  the  latter  has  no  tendency  to  honk  into  t  he 
esophageal  wall.  Ilenrard1  has  devised  special  forceps  for  tin-  particu- 
lar case. 

\o  harm  is  usually  done  if  a  coin  lodged  in  the  esophagus  is  pushed 
into  the  stomach  in  the  course  of  efforts  at  extraction. 

Jf  a  com  or  aiiv  other  foreign  bodv  cannot  he  detected  by  the  fluoro- 
scope  a  radiograph  should  he  made  and  developed  at  once. 

A  com  or  other  foreign  hod\"  \\phich  has  been  located  in  the  esophagus 
by  an  .c-ray  examination,  ami  which  has  resisted  efforts  at  extraction 
through  the  mouth  or  dislodgmenl  into  the  stomach,  usually  requires 
esopliagotomy.  This  is  so  serious  an  operation  that  the  radiologist 
should  uuard  against  everv  possible  source  of  error  in  making  his  diag- 
nosis of  the  presence  of  a  foreign  body  from  the  ./'-ray  appearance. 

A  most  striking  case  in  this  connection  was  that  of  a  patient  who 
was  supposed  to  have  swallowed  a  set  of  false  teeth.  The  radiologist 
thought  he  could  see  them  and  an  csophagotomy  was  performed. 
The}'  were  not  to  be  found  in  t  he  pat  ient  's  esophagus.  The  pat  i cut  di'-d 
from  the  operation,  and  the  false  teeth  were  discovered  under  the  pillow 
in  his  bed.  The  explanation  given  was  that  some  part  of  the  larynx 
was  unnaturally  dense,  and  that  its  shadow  had  been  mi-taken  for  that 
of  a  foreign  body.  The  hyoid  bone,  especially  its  cornu  in  a  lateral 
view,  presents  a  shadow  which  might  be  mistaken  for  a  foreign  body,  a 
misplaced  tooth,  or  a  salivary  calculus. 

.Needles  or  pins  are  sometimes  easily  detected  and  sometimes  do  not 
show.  A  case  of  this  kind  which  the  present  author  examined  was  that 
of  a  circus  pel-former  and  sword  swallower.  He  was  in  the  habit  of 
swallowing  needles,  which  were  probably  caught  in  some  kind  of  recep- 
tacle out  of  sight  in  the  esophagus.  After  the  performance  ihis  recep- 
tacle was  to  be  pulled  up  out  of  t  he  man's  throat.  <  >n  a  cert  a  in  occasion 
some  of  the  needles  were  supposed  to  be  missing,  and  a  few  days  later 
the  author  made  a  radiograph  of  the  thorax,  which  did  not  reveal 
them. 

Fish  bones  and  small  chicken  bor.es  would  UsUailv  not  show  in  a 
radiograph  of  the  thorax;  they  might  if  lodged  in  the  1hro:it . 

Reetemvald-  removed  a  silver  quarter  dollar  located  by  the  .r-ray 
(radiograph  bv  Johnston)  -I1.'  days  after  lodgment  in  the  esophagus. 

Hannecart3  located  a  hard-rubber  dental  plate  which  had  been  al- 
lowed to  remain  in  the  esophagus  for  ten  day-,  the  medical  attendant 
having  been  deceived  bv  the  tact  that  an  esophageal  sound  could  be 
pa --I'd  wit  hoi  it  obstruction.  Esophagi  >t  om  v  was  successfully  performed. 
The  foreiun  bodv  had  caused  a  peri-esophageal  abscess  and  a  necrotic 
condition  of  the  wall  of  the  e-ophaiiu-.  but  no  dyspnea. 

Scatinell'  reports  a  case  of  ,r-ray  localization  ol  a  toivmn  body 
lodii'ed  in  the  esophagus  for  seven  week-.  It  was  successfully  re- 
mi  ivet  1. 

i  I,c  R.-nlinm.  Sopl     |."i.   1<«C>,  p    :!0'J 
-  Nru   V,.rk  Mr,|    ,],,.ir  .  ,l;  n    i:i.  I'.'in;. 

:    l.:i    IJcVlli'  ill'  StnliKiti.l'tui'  .    M :,  \  .    I'.HI.Y 

••  UoM.m  MM.  ;ui<i  S  in.    .'     .•  .  I  >•  •'    -7.  1' 


094  MF.niCAL    KI.KCTH1CITY    AM)    KONTCKN     KAYS 

King1  located  a  child's  tin-whistle  lodged  in  thr  esophagus  for  ten 
days.  Ksophagotomy  \vas  successful. 

A  pin  hidden  in  one  of  the  ventricles  of  the  larynx  would  he  readily 
shown  by  a  lateral  radiograph,  though  undiscoverable  by  the  laryngo- 
-cope.  Mackintosh  and  Downie  have  reported  such  cases.  The  author 
knows  of  a  case  in  his  own  family  where  a  pin  escaped  detection  by 
the  laryngoscope  and  caused  cough,  persisting  for  two  years.  It  was 
finally  dislodged  by  a  lit  of  coughing.  The  .r-ray,  if  it  had  been  known 
at  that  time,  would  probably  have  discovered  it. 

Other  foreign  bodies,  such  as  pins  and  metal  washers,  have  been 
located  in  the  esophagus  by  means  of  the  .r-ray  and  successfully  re- 
moved.- 

Stricture  of  the  Esophagus.-  The  .r-ray  study  of  this  condition 
may  be  done  by  the  use  of  a  flexible  bougie  with  a  metallic  olive-shaped 
extremity,  or.  according  to  a  suggestion  by  ('handler,3  two  such  olivary 
bougies  may  be  used.  One  may  be  pushed  through  the  stricture  and 
then  withdrawn  until  it  engages  behind  it.  the  oilier  being  pushed 
down  to  the  face  of  the  stricture.  The  radiograph  would  show  the 
position  of  the  two  olivary  tips  and  the  distance  between  them.  An 
anteroposterior  picture  is  made  witli  the  plate  behind,  and  using  the 
same  technic  as  in  other  neck  or  chest  radiographs,  according  to  which 
region  oi  the  esophagus  is  affected. 

There  is  every!  hing  to  be  gained  by  fluoroscopy  during  the  extraction 
of  a  foreign  body  from  the  esophagus,  provided  that  one  is  exceedingly 
careful  to  prevent  overexposure.  The  patient  should  lie  face  up  on  a 
canvas  or  thin  wood  table,  with  the  .r-rav  tube  underneath.  The  room 
i-  entirely  darkened,  and  the  image  of  the  foreign  body  and  the  forceps 
oi1  coin-catcher  are  observed  upon  an  open  fluoroscopic  screen  laid  over 
the  patient 's  neck  and  chest .  The  danger  to  1  he  operator  would  be  verv 
great  if  such  cases  occurred  frequently. 

The  .r-Ray  Diagnosis  of  Diverticula  or  Stenosis  of  the  Esopha- 
gus.— This  is  made  by  means  of  radiographs  taken  after  a  patient  has 
swallowed  an  emulsion  of  bismuth,  or  a  paste  made  of  potato  and  bis- 
muth, which  shows  perfectly  black  in  the  local  mn  at  which  its  progress 
i-  arrested. 

The  bismuth  or  iron  emulsion  for  radiograj ih v  of  the  esoj)hagus  should 
form  a  thick  liquid. 

\  thick  paste  of  in  a. -lied  pot  at  o  and  bismut  h  or  iron  is  preferable  to 
tin  li'iuid  fi >r  rai liographic  purposes. 

The  proper  position  is  that  the  patient  lie  flat  upon  his  back  on  the 
plate,  with  the  nibe  vertically  over  the  portion  of  the  esophagus  which 

!.-   MISpected    to   be   the  seat    of  the   lesion. 

Spindle-shaped    Dilatation   of    the   Esophagus.— This   condition 

ha-  bi'en  diagnosed    by  Sjomvi.i  -;  in  leases.      One  patient   was  fourteen 

ninth.-   (,M.    and    was   mven  three  or  lour  t easpoonfuls  of  an   emulsion 

:  ing  s  grains  nl  bismut  h  subnit  rat  e.      A  lateral  ra<  liograph  showed 

'!.••'•-'  i ph.1 1  in i-  a.-  a  narrow  ribbon  (visible  because  of  a <  Iherence  of  part  i- 

:  bi-muthi  down  to  the  level  of  the  eighth  dorsal  vertebra.     There 

:.    became    large   and   dense   in   a   spindle  .-hape.      An  antero- 


THE    T-RAY 


905 


posterior  radiograph  showed  the  spindle-shaped  mass,  but  not  the  traces 
of  bismuth  in  the  upper  part  of  the  esophagus.  The  other  patient,  a 
man  of  thirty-seven  years,  was  given  00  c.c.  of  an  emulsion  containing 
25  grams  of  bismuth  subnitrate.  A  lateral  radiograph  showed  a  spindle- 
shaped  shadow  beginning  at  the  level  of  the  seventh  dorsal  vertebra. 
The  dorsal  radiograph  showed  everything  but  the  upper  end  of  the 
shadow  where  it  was  overlapped  by  the  heart  and  vertebra-. 

Stenosis  of  the  Esophagus  Due  to  Pressure  by  Mediastinal  Tu- 
mors.—Two  cases  of  this  nature  were  diagnosticated  by  Barba1  from 
.r-ray  examinations,  aided  by  the  passage  of  a  sound  filled  with  a  con- 
centrated mixture  of  bismuth  subnitrate  or  provided  with  a  metal  stylet. 

Retropharyngeal  Abscess.-  This  is  a  condition  the  diagnosis  of 
which  may  be  assisted  by  a  lateral  radiograph  of  the  neck.  A  clearly 
defined  area  with  its  convexity  forward  is  traced  behind  the  tract  of 
the  esophagus  and  of  the  larvnx  or  trachea,  but  without  marked  differ- 
ence in  density  from  the  surrounding  tissues. 

A  Tumor  of  the  Neck  is  Diagnosed  in  a  Similar  Way. — ( lenerally 
speaking,  the  differential  diagnosis  between  a  tumor  and  an  abscess  in 
the  neck  by  means  of  the  .r-ray  is  not  so  much  a  difference  of  density 
as  in  the  shape  and  position  of  the  tumor. 

Fig.  Sll.  p.  1228,  is  a  radiograph  taken  of  a  patient  under  treatment 
for  recurrent  carcinoma  of  the  neck.  The  original  growth  was  in  the 
larynx,  and  a  complete  laryngectomy  had  been  performed  about  a  year 
before  this  picture  was  made.  There  was  a  recurrence  of  the  cancerous 
growth  in  the  tissues  of  the  neck,  forming 
at  the  time  that  he  came  under  treat ment 
a  mass  about  the  size  of  a  small  apple,  and 
occupying  the  position  from  which  the 
larynx  had  been  removed.  The  patient 
was  still  able  to  breathe  through  a  trache- 
otomy tube,  but  the  growth  had  com- 
pletely obstructed  the  esophagus.  The 
results  of  .r-ray  treatment  in  this  case  are 
described  in  the  chapter  on  "The  Thera- 
peutic I'se  of  the  .r-Hay."  The  picture 
-hows  thi-  growth  as  a  portion  of  the  tis- 
sue, not  differing  in  density  very  much 
from  the  other  solid  tissues  of  the  neck. 
It  show-  the  air-space  of  the  trachea  ter- 
minating suddenly  at  the  level  of  the 
growth.  No  trace  of  the  original  carti- 
lage- of  the  larynx  is  to  be  seen. 

Radiographic    Diagnosis  of  Laryngeal 
Lesions.      It  i-  very  important    to   have  a 

radiograph  of  the  normal  larynx  taken  with  one's  own  apparatus  and 
technic  as  a  m<'an<  of  comparison.  A  chart  showing  the  location  of  the 
different  cartilage-;  and  other  part-  of  this  -ection  of  the  neck  is  given 
in  Fi<r.  700.  The  radiograph  itself  should  be  a  lateral  one.  with  a  small 
plate  held  as  closelv  as  possible  to  the  side  ot  the  neck,  and  with  the 
aiiticathode  at  a  considerable  distance,  say  2M  inches,  from  the  plate. 
The  best  re-ults  will  be  obtained  with  a  1-inch  spark  and  for  a  man  of 
about  150-pound-  '.)()  ma.  for  twelve  second.-  or  any  other  equivalent  of 
odo  ma.  seconds. 

1   ItilonnH   Me.llea.    Dec.  _>:',.   HKl',. 


1 1.;.  .00.  -]  )i;i^r:un  of  anpear- 
1  nl' the  larynx  in  :i  lateral  radio- 
•:..  //,  I'.ody  of  hyoi.l  bone; 
rnrnua  of  hvoi.l  hour:  /•;,  epi- 
:  '/',  upper  ciininu  of  thyroid 
I'.-irtilajit1;  A",  prominence  of  larynx  : 
'/''•.  trachea:  I",  ventricle  of  larvnx 
iaitcr  t  ;ra<lHT(r). 


MKDICAI.    KI.Ki  TKK  m     A.\!>    H<  >.\T<  i  KN     KAY 


The  late  Dr.  Ka->al>ian:  reported  radiographs  .showing  tumors  of  the 

t  rachea  and  vocal  cord-. 

THE   CHEST 

Fluoroscopy  i-  of  ureater  value  in  examination  of  the  chest  than 
almost  anywhere  el-e.  The  relatively  sliirht  density  of  the  lun^s 
and  the  thinne.--  of  the  chest  walls  permit  sufficient  radiance  to  pass 
through  to  uive  a  liood  imasz'e  on  the  screen.  Fractures,  or  disease 
of  the  clavicle  or  ril>-,  are  readily  detected;  those  of  the  vertebra*,  and 
e-pcrially  of  the  -termini.  being  more  difficult.  The  condition  of  the 
him:'-  i.-  very  well  studied  in  this  way  with  a  (i-inch  spark  equivalent 


and   ."   ma.,   the  anticathode  lieinji   \~i  or  L'O  inehes  fi'om  the  c'liest    wall. 

(her    in    front    or   liehmd.      In   an   entirei\-   dark    room,   and   with 

.'     flilnrcsceiil     -creen.    the    mo\'ement-    of    liie    diaphragm    may    lie 

' .  al-o   'he   I ?-aii.-liic('iicv   of    the   lun«i's.  and   a   diminution   of    the 

•'••'    indicate-   con-olidat  ion   of  the   lunu  or  ihieken'mn-  «,f  the   pleura: 

iii    the    |MHC_!    a!-o   -how,   and    in    many    case.-    thickening  of  the 

the     hroiichi     and     deposit-    in     the     l\mphatic    vessels    and 

Pleuritic    effu-ion    or    emp\ema    ma\'    be    determined    in    this 

IIH     -mailer   enclo-ed    fluoi'o-cope    ha-    the   advanta.ue   of   liein^ 

-     i!  i'-«  iii  -.-en  icnl     to    da  rken     t  lie    room    complel  elv. 

N-  •     x.  ••! .    M   .!    .I'.ur..  IM  1,    L':i,  I!»i7.     .  •>7I.<. 


A  prolonged  study  of  the  fluoroscopic  image  is  dangerous  to  operator  ;nid 
patient.  The  heart  cut)  IK-  distinctly  -een  ;ind  each  puls;it  ion  \v;it  died. 
it  is  often  desirable  to  estimate  the  si/e  of  the  heart  with  an  approach 
to  accuracy,  and  for  thi-  purpose  the  ort  liodiagraph  is  of  service.  One 
model  is  illustrated  in  Kig.  702.  It  consists  of  lube-stand  and  fluores- 
cent screen-holder  combined  in  such  a  way  that  they  move  simulta- 
neously like  the  prongs  of  a  pitchfork.  At  'the  center  of  the 
lead  pencil  which,  when  the  screen  is  moved,  make 
of  paper  which  is  held  in  a  fixed  po-ition.  The 
1  ween  t  he  .r-ra  t  ube  and  I  he 


image  of  t  he  upper  par!  of  I  he 
heart  appears  to  be  at  1  he  center 
o!  t  he  screen  it  means  t  hat  I  he 
t  ube  and  t  he  upper  border  of  t  he 
heart  and  t  he  lead  pencil  anxill 
at  the  same  level.  A  mark  made 
there  is  actually  at  the  level  of 
t  he  upper  border  of  the  heart. 
In  t  he  same  way  the  act  ual  level 
of  the  lower  border  may  be 
marked  on  the  paper,  and  by 
carrying  the  screen  and  its  pen- 
cil along  the  visible1  border  of 
the  image  an  outline  is  drawn 
which  is  of  the  natural  -i/e. 
Thi-  is  true  in  spite  of  the  fact 
t  hat  t  he  heart  is  at  a  consider- 
able distance  from  the  screen, 
and  that  consequently  its  visible 
image  at  any  stage  is  enlarged  in 
proport  ion  to  its  distance  from 
t  he  plate.  The  t  racing  consist  s. 
I  hen.  of  a  number  of  points  rep- 
re-enting  the  true  po-ition  of 
portions  which  they  represent  on 
1  he  1  lorder  of  t  he  heart .  A  con- 
vincing demonstration  of  this  i- 
!< >  place  a  key  rat  her  clo-e  tot  he 

paper   and   another  of   the  same       .,    ,1.,,,^-rous    wp.^ur..   nf'the    operator   and 
si/e    much     further    away    and       patirnt. 
quite    clo-e    to   the  .r-ray    tube. 

The  fluoroscopic  image  of  t  he  first  is  of  about  the  true  size,  while  that  of  the 
second  is  great  ly  magnified,  yet,  on  pa --ing  t  he  pencil  around  t  he  borders 
of  the  two  image's,  both  tracings  are  found  to  be  of  the  same  si/e.  and 
that  is  the  true  -i/e  of  the  keys.  The  ort  liodiagraph  does  not  usually 
provide  the  means  for  making  a  radiograph  -bowing  the  true  si/e  of  the 
heai'i  :  the  re>ult  obtained  is  only  a  pencil  tracing  of  the  orthodiagraphic 
image.  The  apparatus  may  be  arranged  so  that  the  tube  is  under  a 
table  on  which  the  patient  lies  with  the  paper  and  screen  above  him. 
The  present  a ut  hor  made  early  experiments  looking  toward  the  discovery 


90S 


MKDU'AL    ELECTRICITY    AND    RONTGEN    KAYb 


cellular  screen,  the  principle  being-  that  the  x-ray  is  allowed  to  escape 
only  through  a  group  of  nine  parallel  tin  cell/,,  each  -\  inch  in  diameter 
and  ")  inches  long.  The  tube  is  enveloped  in  a  localizing  shield  in  the 
orifice  of  which  the  group  of  cells  is  fixed.  The  whole  is  suspended  by  a 
cord  long  enough  to  permit  of  motion  in  everv  direction  far  enough  to 


!•'!«.  70:5 — Orthodiagraph  with  t\v< 


cover  the  entire  organ  to  be  depicted,  and  permitting  the  group  of  cells 
to  remain  vertical  all  the  time.  The  plate  lies  ilat  upon  a  table,  the 
portion  to  be  radiographed  on  top  of  that,  and  the  tube  is  suspended 
just  high  enough  not  to  let  the  end  of  the  cellular  screen  touch  the  flesh. 
As  not  more  than  a  square  inch  of  the  plate  receives  the  rays  at  one  time, 
the  duration  of  t  he  exposure  would  have  to  be  as  many  times  longer  than 
normal  as  there  are  square  inches  in  the  picture  desired.  This  does  not 
mean  that  the  patient  is  exposed  to  the  .r-ray  an  abnormal  length  of 
time.  Kach  square  inch  of  the  required  area  of  the  patient  receives  a 
normal  exposure.  Naturally,  one  would  make  the  picture  much  more 
than  the  dimensions  required  to  show  the  actual  si/e  of  the  organ  or 
foreign  bodv  under  examination.  The  image  of  anv  very  small  object, 
like  a  needle,  is  more  blurred  by  this  method  than  by  ordinary  radiog- 
raphy. 

A  variation  in  the  ort  hodiagraph  has  been  suggested  by  (Irocdel.1 
Tl  consists  in  placing  the  paper  and  the  crayon  behind  the  .r-ray  tube. 
Tin-  enables  one  to  place  the  fluorescent  screen  directly  in  contact  with 
the  patient.  There  is  only  a  small  metal  pointer,  which  moves  over  the 
surface  of  the  screen  and  does  not  interfere  at  all  with  an  accurate  view 

1  Munch,  incd.  \Vorh.,   1'KMl. 


THK    X-RAY 


909 


of  the*  image.  The  crayon  is  in  a  line  continuous  with  the  normal 
ray. 

One  form  of  orthodiagraph1  lias  two  screens  (Fiji.  703),  one  for  the 
orthodiagraphic  tracing,  with  a  small  diaphragm  in  front  of  the  x-ray 
tube,  and  another  for  a  general  view  with  the  diaphragm  removed. 

This  may  be  used  to  make  an  ort  hodiagraphic  radiograph  by  first 
making  a  tracing  of  the  heart  and  the  general  landmarks  ot  the  chest 
without  the  small  diaphragm.  Then  applying  the  latter  and  putting  a 
photographic  plate  in  place*  of  screen  Xo.  f>  (Fig.  703)  carry  the  pointer 
over  tin*  same*  pencil  lines  again. 

Orthoeliagraphy  is  very  far  from  being  indispensable.  An  ordinary 
radiograph,  made  with  the  tube  at  the  proper  distance  from  the  plate  to 


i<i-  70  I- .    -Radiography  of  the  chest.     Supine  upon  the  plate.     The  dial  is  a  homo- 


made   clinometer.      The   weighted    hand    hanirinji   free   shows   at    what   angle  the  tub 


inclined ;  especial! v  useful  in  radiography  of  the  pneumatic  sinu 


correspond  with  the  thickness  of  the  part  examined,  will  give  an  imago 
from  which  a  correct  estimate  of  the  sixe  of  the  object  may  be  made. 
The  ordinary  radiograph  or  the  stereoscopic  radiograph  has  the  ad- 
vantage of  giving  a  first-class  picture*  of  the*  object,  and  of  all  that  part 
of  the  body  which  tin*  ort  hodiagraph,  e*ithe*r  tracing  or  radiographing, 
prad  icall v  cannot  do. 

Radiography  of   the   chest    may    be   performed   with    the*   object    of 
securmu;  good  detail  of  the  vertebra*  or  u'ood  detail  of  the*  lungs.      For 
the  vertebra1  the  equivalent  spark  should  be  ~>  inches,  and  in  a  man  of 
1  Knnmen  ( 'nntrress,  May.  1<H>.">,  exhibited  by  Polyphos  Co. 


1  I  II  II  I 


about  h~>!)  pounds  •>(>  ma.  tor  thirteen  .-econds  or  any  other  equivalent 
<  >f  :>!Mi  ma.  seconds'  i-xposuri1.  The-e  different  expo.-ure-  .irive  equivalent 
re-ults  upon  a  photographic  plate,  the  patient  lyinir  on  his  hack  upon 
the  plate,  and  the  tulie  at  a  di-iaiice  of  2M  inches  from  anticathode  to 
plate.  Shorter  exposure.-  under  the  same  condition-  will  produce  pic- 
tutv-  \viiich  are  very  tiood.  Uit  not  quite  so  sul)stantial  appearing.  For 
t  he  detail  in  t  he  1  in  ILL-  I  prefer  4  -inch  spark  and  .'!(,Hl  ma.  seconds,  and  the 
reMiit  may  l>e  tie>!  uhtained  if  the  picture  is  taken  in  so  short  a  time  that 
the  patient  can  hold  hi.-  lnvatli  and  the  chest  !>e  motionless  during  the 
entire  expn-ure .  To  obtain  still  inoi'e  rapid  pictures  of  the  chest  an  in- 
ten-ifyin^  screen  may  he  used.  The  exposure  may  be  reduced  to  a  snap- 


-hot .      fust  ant  alieoiis  radiography  of  t  he  clie-t  ha-  been  attempted  in  tin1 

-en-e  in  \vhich  the  t  erni  m-t  ant  aneous  i.-  u-ed  in  rc^a  rd  to  snapsliol  jihoto- 

uraph-  with  a  kodak  camera:  and  with  an  extremely  powerful  apparatus 

p.  7!7     one-i jiiarter  or  one-hali  second  excellent  expo-ure,-  are  practic- 

vithoul  an   inlensifviny:  -creen  and   o|   one-third  that  time  \\itli  a 

-i-feeji . 

l:i  vadiotira|)hiiiLL  the  che-1  the  lx-1  picture-  are  obtained  with  the 
lowi  -'  deu;ree  of  vacuum  which  will  -how  dearly  through  the  chest  with 
the  -:  o-cope.  Sudi  a  \'aciium  will  take  a  linle  longer  lo  produce 
a  pi<-1  .  the  result  will  lie  both  better  contrast  and  better  detail 

t  han  wil  h    ,    hiiiln-r  va 


1001 

.\neiiry.-m  n[    i  he  aorta  shows  very  well   in  a   radiograph   and  so  do 

lep'tsits  in  the  mediast  inal  L;!and>  ami  foreign  bo. lie-  in  the  esophagus 

and    hi!i'_rs.      I "> y   allowing   ihe   patient    to    -wallow   an    emul-ion   of    bi.— 

mull)  or  iron,  which  i-  very  opaque-  to  the  .r-ray,  we  may  demons)  rale 

the  pre-ence  ot  a  divert  iciil n n i  of  a  <triclui'e  of  the  esophagus. 

The  dorsal  vert<>hra'  are  best  studied  in  a  radiograph  made  with  the 
tube  •)  inches  to  one  >ide  of  the  meihaii  line,  so  that  the  shadow  of 
the  sternum  will  1  all  to  one  side  oi  that  of  the  spine— plat  e  behind,  t  ube 
in  front  of  pat  ient . 

The  Diaphragm. —  Diaphragmatic  paralysis  is  readily  detected  by 
means  of  t  he  .r-ray.1 

Commencing  pulmonary  tuberculosis  is  indicated  bv  diminution  of 
translucency  at  one  apex  and  lowering  of  the  corresponding  half  of  the 
dia  j  (hragm.- 

The  convexity  of  the  diaphragm  in  its  average  ])osition  on  the  riidit 
side  is  Kil  centimeters  below  the  horizontal  episternal  line,  and  1^1 
centimeters  below  this  line  on  the  left  >ide.  The  amplitude  of  move- 
ment is  the  same  on  both  sides,  and  is  about  IN  millimeters.  The 
relation  between  the  amplitude  of  excursion  and  the  functional  an.ule  of 
the  ribs  varies  in  different  normal  individuals,  according  to  the  respira- 
tory type.  The  conditions  in  the  amplitude  of  excursion  on  either  .-ide 
may  have  a  pathologic  significance.3  Reduction  in  the  functional 
an.irle  is  suggestive  of  tuberculosis. 

The  Costal  Angle. — ( iuilleminot'  and  Bouchard  and  (iuilleminot5 
have  made  an  especial  study  ot  this  angle  in  its  relation  to  pulmonary 
diseases.  It  is  described  as  the  angle  between  a  line  drawn  from  the 
center  of  the  sternum  to  the  upper  border  of  a  rib  during  inspiration, 
ami  another  similar  line  drawn  during  expiration.  These  two  lines  are 
traced  by  means  of  the  orthodiaseope  or  in  two  radiographs.  This 
angle  varies  direct!}'  as  the  amplitude  of  the  oscillat  ion  of  t  he  diaphragm. 
It  is  very  much  diminished  in  pleurisy  and  in  tuberculosis. 

The  Cardiac  Area.— The  cardiac  area  is  reduced  in  persons  with  a 
tendency  to  consumption,  and  also  in  persons  with  pulmonary  tubercu- 
losis.  It  i-  larger  than  normal  in  cases  which  have  recovered  from 
i  uberculi  isis.G 

Topography  of  the  Thoracic  Organs  in  Radiographs.  'The 
Tube  at  the  Level  of  the  Sixth  Dorsal  Vertebra.  —  1.  An.it  ropnxh  rior 
\ijrnph  ii'ilh  ///c  l'l'i/i  Itdi'i/il  i  l-'in.  TOtii. — The  ,x/;/'m  shows  quite 
clearlv  in  the  upp<>i'  pail  ot  thorax  and  neck,  the  spaces  between  the 
bodies  of  the  vert  el  >ra'  being  verv  stn  in.Li'K"  marked.  It  sin  >ws  as  a  darker 
si  ailow  with  parallel  borders  in  the  part  of  the  picture  where  it  is  cov- 
ered bv  the  heart,  but  sometimes  the  separate  bodies  of  the  vertebra' 
may  not  show  distinctly.  The  spinous  processes  of  some  of  the  vertebra- 
in  this  region  may  show  as  small  rounded  spots. 

The  trui -h<  <i  shows  as  a  clearly  defined  band  of  t  ranslucency.  extending 
down  in  front  of  the  vertebra1  to  the  level  of  its  bifurcation  isixth  dorsal 
vert  el  >ra  ). 

i  Cliuidf-,  ( 'nnsrcss  of  Tul»Tcu!(i-i-.  P:iris,   1  S'IX. 

-  pit-rlfi-c.  ( 'nnsin^s  of  Tiiht-n-uln-i-j.  i':iri-.    1VK. 

:i(  lui  11, •minor,  ('.  I!.  <lc  1'Afiul.  <l>*  Sri.Min-.    141,  2S1,  July  lM,    I'.Kl.l. 

1  l.c  Itailiiitn,  Sept.   1.").   1  !)().'>. 

:-c.  K.  Arail.  dcs  Sciences,  r-xxviii.  1  I-'1.  June  1'J.   l^H'.t. 

e<  luillt-niinot,  ('.  1!.  ik-  I'Afiul.  ih-<  S«-i.-jH-t-<.    !  Kl,  SfJ.  Mnn-li  2."),    ]W.~,. 


1002 


MKDICAL    ELECTRICITY    AND    UONTCEN     HAYS 


The  bronchi  and  their  branches,  inside  and  outside  of  the  lung, 
cannot  ordinarily  he  seen  in  the  radiograph. 

The  clnricli*  show  distinctly,  and  so  does  their  articulation  with  the 
manuhrium  sterni. 

The  xtcrniu/i  is  not  usually  distinctly  visible  in  the  dorsal  radiograph, 
only  its  manubriuni  can  ordinarily  be  traced. 

The  rihs  show  very  well,  and  even  those  overshadowed  by  the  heart 
can  be  traced  in  the  plate. 

The  lnn</x  show  a  certain  mottling,  which  is  apparently  the  shadow  of 
blood-vessels  and  not  of  air-passages.  It  is  important  to  distinguish 
this  from  the  abnormal  appearance  due  to  tubercular  deposits. 

The  canlioruxcnhir  ///</.«  (Fig  70(>,  from  liieder1)  shows  a  shadow 
which  is  bounded  as  follows:  Beginning  close  to  the  border  of  the  spine 
the  edge  of  the  shadow  of  the  superior  vena  cava  passes  down  almost 
parallel  with  the  border  of  the  spine  and  merges  into  the  shadow  of  the 
riidit  auricle.  The  convexitv  of  the  latter  extends  the  width  of  the 


pinal  shallow  to  the  right,  arid  then  curves  in  again  to  merge  into  the 


ri-ht    ventricle  at    the    intersection   of    the  diaphragm  and  the  spinal 


Then  the  cardiac  outline  is  lost    in  the  shadow  of  the  spine. 


At  the  left  of  the  spine  the  shadow  of  the  ventricles  is  at  first  continu- 
ous with  that  of  the  diaphragm  covering  the  liver  and  stomach,  but 
l;tt(  r  diverges  from  it.  The  apex  of  the  heart  is  free  from  any  other 
shadow,  and  is  about  twice  the  width  of  the  shadow  of  the  spinal  column 
from  the  left  bonier  of  the  latter.  It  is  not  ipiite  at  the  lowest  level 
of  the  cardiac  shadow.  From  this  point  the  border  of  the  shadow 
pa-se<  upward  and  inward,  showing  a  slight  concavity  where  the  left 

.•'•utricle  merges  into  the  left  auricle,  and  having  a  convexity  over  the 
onary   artery,    which    is   at    a    considerably    higher   level   than    the 

•onvexity  f)f  the  ri^ht  auricle.  There  is  <|uile  a  distinct  angle  be- 
tween the  border  of  the  pulmonary  arterv.  passing  upward  and  inward, 
•  '  1  ih.it  of  the  aorta,  which  passes  upward  with  a  slight  convexity  out- 
ward. 

_',    <  ''i  i'i/  1:  u'(i.--rnltir  lnj>i}i/!'iij>lii/  in  mi   .  1  nit  r»  im.<li  /•/<!/•  lt'<iil  i  ui/ru  ]>}i  with 
//"    /"'        //  /•'/•((/,/.      The  spine  looks  larger  and  less  distinct,  the  clavicle 
snialliT  and  more  distinct.     The  heart  area  is  a  little  smaller  and  more1 
:  l-'ort-ch,  :i.  -1.  ('«•}>.  ilcr  HncntK«'iist  .,  100'J,  vol.  vi,  p.  ll.s. 


THK    0--HAY  1003 

distinct.  In  this  picture  ( Fig.  707,  from  Kieder1)  the  border  of  the  vena 
cava  begins  at  the  junction  of  t lie  shadows  of  the' right  clavicle  and  the 
right  border  of  t  he  spine,  and  forms  a  slight  convexity  as  it  passes  down, 
but  before  it  reaches  the  cardiac  area  it  is  covered  bv  t  he  spinal  shadow. 
'1  he  border  of  the  right  ventricle  becomes  visible  at  a  lower  level  and 
forms  a  convexity  which  terminates  at  the  junction  of  the  diaphragm 
and  the  spine.  It  should  not  extend  more  than  half  the  width  of  the 
spinal  shadow  beyond  the  right  border  of  the  latter.  From  the  left 
border  of  the  spine  the  shadow  of  the  left  ventricle;  and  the  apex  of  the 
heart  extend  outward.  It  may  appeal1  in  direct  contact  with  the  dia- 
phragm, but  very  often  a  strip  of  hin.tr  is  seen  to  intervene  in  this  ventral 
position,  especially  if  the  .r-ray  tube  is  at  quite  a  hi.trh  level  behind  the 
back.  The  left  ventricle  and  the  left  auricle  and  the  pulmonary  artery 
form  three  distinct  convexities,  extending  upward  and  inward  to  a  point 
near  the  spinal  shadow,  where  the  border  of  the  descending  aorta  is  seen 
close1  to  the  spinal  shadow,  and  extending  down  from  the  clavicle  to  the 
heart  area:  it  is  only  slightly  convex. 

( \\  emberg's  Atlas  der  Radio.trraphie  der  Hrust  ( )rgane.  K.  M.  Kngel, 
Vienna.  I'.tOl,  gives  an  excellent  guide  to  the  topography  in  antero- 
posterior  radiographs  of  the  chest.) 

A  convexity  in  the  second  left  intercostal  space  extending  outward 
from  the  median  shadow  in  an  anteroposterior  radiograph  is  not  usually 
due  to  an  aneurysm.  It  is  commonly  due  to  the  aorta  being  placed  a 
little  farther  to  t'lie  left  than  usual. 

A  diffuse  swelling  of  the  aorta  is  sometimes  seen  in  old  persons, 
('specially  in  a  radiograph  taken  with  the  tube  behind  and  to  the  left. 
It  indicates  atheroma.  not  usually  aneurysm. 

Radiography  in  Ot/nr  Than  the  ^tii/itfnl  I'lnnc. — The  first  investiga- 
tions of  the  thoracic  organs  by  means  of  .r-ray  examination,  made  in  a 
number  of  different  directions,  were  by  v.  Criegu'-'  and  by  Holxknecht .:; 

Kieder'  has  done  more  than  anyone  else  to  make  the  oblique  and 
lateral  methods  of  examination  practicable. 

The  tube  is  usually  placed  at  the  level  of  the  sixth  dorsal  vertebra, 
and  trenerally  at  a  distance  of  not  more  than  .~>0  or  00  centimeters  from 
the  plate. 

.'!.  Topography  of  the  Heart  and  (ircat  1  CNNC/S  in  Oblique  Radiographs 
of  fhi  TJmrnx.  —  These1  pictures  are  made  with  the  tube  at  the  level  of  the 
sixth  dorsal  vertebra,  and  either  in  front  or  behind  at  an  angle  of  1") 
degrees  from  the  median  line,  the  plate  being  diametrically  opposite. 

IF////  the  TH/X-  Htfiind  mid  l»  Kith*  r  Side.-  The  two  oblique  pictures 
with  the  tiilx1  behind  show  the  spine  somewhat  curved,  its  concave 
luirder  smooth  and  formed  by  the 
border  uneven  and  formed  by  th 
and  confused  by  the  angles  of  th 
large  and  somewhat  vague. 

The  clavicles  show  at  a  different  an  trie  upon  the  two  side's. 

\Vith  the  T nl>c  in  I'' rout  unit  to  lather  >^i<lc. — The  spinal  column 
shows  more  distinctly;  it  is  curved  and  the  concavity  is  smooth,  formed 

1  Furtsoh.  a.  il.  <",,•!>.  der  KMfniLr''n-t  .  vol.  vi,  p.  1  1  "v 
-  Ycrhand.  il.  Knnirtvs,-.  f.  in.  Mrdi/in.  Karlsbad,   ivi'.i. 

3 Wicn.  Klin.  \Vnrli..  I'.KN).  \o.   in.   and    Di.-  llnrntjronnlnciorho  Diacnostik  der 
Krkrankunirrn  der  Hrusti'niKr'wciih1  Hanilmrir.   Fuc:i~  (iratV  and  Sillcn.   1 '.)()!. 
!Fort.<rh.  a.  d.  (n>h.  d.-r  Knt'iitircnst..  veil.  vi.  r.mj.  p.   M  t. 


bv  the  bodies  di'  the  vertebra1,  while  the  convexity  presents  a  notched 
border  ilue  to  the  different  processes  of  the  vertebra)  ami  to  the  angles 
01'  tin-  ribs. 

The  two  scapula4  present  ([iiitea  different  appearance.  The  one  on 
the  >ame  side  as  lite  plate  presents  its  customary  appearance,  while  the 
other  one  is  seen  in  profile,  and  seems  like  a  rylindric  bone  not  more 
than  an  im-h  in  diameter,  extending  downward  from  the  shoulder-joint. 

(n}  '/'A*  ( 'iinlifn'dxculiir  Shmloir  \Ylnn  the  T/I/IC  /x  /><//;'/?</  and  to  the 
I. 'ft  i  Flu;.  70.S1.-  Its  right  border  may  be  traced,  from  below,  where 
it  is  formed  by  the  right  auricU1.  It  is  separated  tVom  the  spinal  shadow 
by  a  translucent  area,  and  as  it  passes  up  parallel  with  the  border  of 
the  spine  it  is  formed  by  tin1  ascending  aorta.  The  arch  of  the  aorta 
casts  ijiiite  a  broad  shadow,  which  ends  abruptly  in  the  t ranslucency 
of  the  hum  substance  at  t  he  level  of  the  clavicles.  The  left  border  passes 


ri.irht;   .r-rav   tube    behind  and   to   the   left; 


down  and  to  'lie  left,  and  is  formed  by  the  arch  of  the  aorta,  the  de- 
sci  nding  aorta,  tin-  pull  nonary  artery,  and  the  left  ventricle.  It  merges 
in'o  the  .-hadow  of  the  diaphragm  at  the  apex  of  the  heart.  The  entire 
cardiovascular  shadow  looks  like  that  of  a  tenpin  used  in  bowling- 
alleys. 

The  cfiOfiiitifinn  passes  down  through  tin-  transparent  space  between 
the  heart  and  the  .-pine,  and  may  sometimes  be  made  out  in  the  radio- 
graph a-  ;;  dark  .-trip.  Its  course  is  rendered  more  visible  bv  the  intro- 
duction of  a  metallic  sound.  'This  oblique  radiographic  position  is 
favorable  for  the  detection  of  foreign  bodies,  strictures,  or  diverticula 
ol  ihe  esopha^u-.  Diseases  of  the  esophagus  are  considered  on  p.  !)'.•! 

(l>\    I'/i iimii'ii jili i/  of  l/ir  ( 'firi/inrtixciildr  .1/^.vx  /'//  n  Itadinr/raph   witli  flic 

']  i/l»    l!i  hi  mi  inn!  in  Hit'  Iliijlil. — There  is  the  same  clear  space  between 

the   heart    and    the   -pine,   but   somewhat    narrower,   and   this  is   almost 

median  line,  as  indicated   bv   the  episternal  notch.     The  shadow 

of  the  e-i ,;  ihau'iis  may  be  visible. 

c  I 'o/io'irn /i/i  i/  in  Unit ii>tjr<i  jilix  of  tin  Clnxl  ir/'/li  Hit  Tube  in  Front 
ami  In  i.  'In  i  >'/</<.  The  cardiovascular  mass  casts  a  shadow  which  is 


enlarged  and  indistinct. 
pulmonary  blooi  1-vessels, 
m  such  a  pict  ure. 

Oblique  radiogra])hs  are  especially  valuable  in  the  diagnosis  of 
aiieurysm,  lesions  of  the  esophagus,  and  tumors  of  the  mediastinum. 

Lateral  Radiography  of  the  Chest. — This  is  only  practicable  in 
thin  and  slender  patients,  and  only  with  the  tube  on  the  right  side. 
The  pictures  are  vague,  weak,  and  do  not  even  give  a  good  image  of 
the  libs.  The  reason  for  this  is  that  there  is  a  great  thickness  of 
tissue  to  be  traversed,  and  consequently  great  absorption  of  the  ./'-ray 
and  great  dispersion  or  development  of  secondary  ravs. 

Normal  Radiographic  Appearance  of  the  Heart  and  Great 
Vessels. — Arcarisi1  has  studied  this  subject  in  healthy  persons  of 
various  ages  and  of  both  sexes.  He  finds  that  the  shadow  of  the  whole 
cardiovascular  mass  presents  in  all  cases  an  indented  and  vertical  right 
border  which  does  not  pulsate.  This  outline  is  produced  partly  by  the 
vena  cava.  The  left  margin  pulsates,  passes  from  the  pulsating  apex 
obliquely  upward  and  inward  almost  to  the  border  of  the  sternum,  and 
then  from  about  the  level  of  the  second  intercostal  space1  curves  out- 
ward to  form  a  pulsating  semicircle.  The  latter  is  formed  by  the 
shadows  of  two  vessels  which  overlap:  the  left  portion  of  the  arch  of  the 
aorta  and  the  pulmonary  artery.  These  two  pulsating  portions  of  the 
cardiovascular  shadow  are  often  seen  separately  in  old  persons  and 
others  in  whom  the  entire  mass  is  somewhat  elongated.  The  shadow 
increases  in  width  as  well  as  in  length  as  the  person  becomes  older.  It 
is  quite  short  in  children  (Fig.  (>',)<).  p.  W2\  where  the  abdomen  is  so 
much  more  developed  than  the  chest. 

Alterations  of  the  Cardiovascular  Area  in  Disease. — An  in- 
crease of  infra-abdominal  pressure  shortens  the  shadow  of  the  cardio- 
vascular bundle.  Pleural  effusions  or  adhesions  variously  displace  or 
deform  it.  Cardioptosis  (Kummo's  disease)  causes  elongation  and 
displacement  dowmvard,  with  slight  increase  in  width  at  the  base  and 
\\iih  two  separate  pulsating  areas  at  the  left  side  instead  of  a  continu- 
ous one.  The  appearance  in  this  disease  is  very  different,  according  to 
whether  the  patient  is  lying  down  or  standing  up. 

Enlargement  'or  reduction  in  the  si/e  of  the  heart  shows  in  the 
radiogra]  >li. 

Pericardia!  effusion  shows  as  an  increase  in  t 
probable   diminution    in    the    visible    pulsation, 
diagnosis  was  reported  by  Janeway,2  in  which  "> 
-I  by  lap] ting. 

:! out  gen  ray  diagnosis  of  compression  of  the  superior  vena  cava 
aortic  dilatation  was  made  bv  Dopier  in  the  case  of  a  man  with 
;is,  edema  of  the  skin  of  the  chest 
.  but  no  cardiac  murmurs. 


w  Y. 


1006  MEDICAL    ELECTRICITY    AND    KONTCiEN    KAYS 

Holzknecht1  luis  made  numerous  observations  upon  dead  and  living, 
normal  and  diseased  persons,  "which  confirm  the  above  statements. 

Amui'i/xni  of  the  Aorta. — This  condition  is  evidenced  by  an  un- 
natural extension  of  the  normal  shadow  of  the  upper  part  of  the  cardio- 
vascular mass.  The  shadow  pulsates  and  varies  in  position,  according 
to  the  part  of  the  aorta  which  is  affected.  Baetjer,-  from  a  study  of 
101  cases,  gives  the  following  classification:  (1)  Aneurysni  of  the  ascend- 
ing aorta  gives  a  shadow  which  extends  more  to  the  right  than  to  the 
left  of  the  sternum.  It  lies  above  the  heart,  and  is  nearer  the  anterior 
than  the  posterior  thoracic  wall.  ('-)  Aneurysni  of  the  arch  of  the  aorta 
produces  a  shadow  which  extends  a  little  further  to  the  left  of  the 
Mernum  and  to  various  levels  toward  the  neck.  It  lies  nearer  the 
anterior  than  the  posterior  wall  of  the  thorax.  (-•>)  Aneurysni  of  the 
descending  thoracic  aorta  casts  a  shadow  to  the  left  of  the  sternum 
and  is  in  relation  with  the  posterior  wall  of  the  thorax. 

The  cases  which  have  been  referred  to  the  author  have  often  pre- 
sented the  .r-ray  appearance  of  an  abnormal  opaque  mass  in  the  upper 
median  part  of  the  chest,  suggestive  either  of  a  mediastinal  tumor, 
tubercular  or  malignant,  or  of  an  aneurysm.  In  one  case  the  patient 
was  a  large  young  man  of  apparently  splendid  physique.  The  rational 
symptoms  and  physical  signs  were  suggestive  either  of  tuberculosis  or 
aneurysm.  and  the  radiograph  was  regarded  as  probably,  but  not  cer- 
tainly, indicating  aneurysm.  The  patient  died  a  few  weeks  later  from 
a  Mii^le  .-udden  hemorrhage,  which  was  regarded  as  positively  arising 
from  the  rupture  of  an  aneurysm. 

Many  radiographs  of  tubercular  cases  show  an  area  of  opacity  in  the 
upper  part  of  the  chest  continuous  with  ihe  cardiac  shadow  and  ex- 
tending to  one  side  of  the  spinal  shadow.  OIK*  patient  had  all  the  symp- 
toms of  pulmonary  tuberculosis  except  hemopt  vsis  and  died  a  few 
months  later  of  exhaustion.  The  condition  of  the  rest  of  the  lung 
will  aid  one  in  deciding  whether  such  a  shadow  is  cast  by  consolidated 
pulmonary  tissue  or  bv  an  aneurvsm. 

Aneurism  of  tin   Innoininntc  .\r/<ri/.  —  Kassabian3  reported  a  radio- 
showing an  aneurysm  of  the  innominate  artery.      The  diagnosis 

confirmed  by  a  post-mortem  examination. 

he  various  posit  ions  of  t  horacic  aneurysm.  as  revealed  by  the  .r-ray, 

been  clas-ified  bv   Baetjer1  as  follows: 

)   Aneurysm  of  the  ascending  portion  of  the  aorta  usually  casts  a 

»\v  more  to  the  right  than  to  the  left  of  the  si  ernum  above  t  he  heart , 

by  locali/.at  ion  would  be  found  to  be  nearer  the  anterior  than  the 

•nor  wall  of  the  1  horax. 

')  Aneurysm  of  the  transverse  arch  casts  a  shadow  slightly  to  the 
si  en  mm,  and  1  his  shadow  extend.-  well  up  into  the  neck,  and 


1  \Yicn.   Klin.  \Ynoh.,  Mnrch  V   1('<>(I 
!  '.'ill.  Johns   I  lopkins   I  lo.-p.,  Jnn.,    I '.Kid. 
'..    •.    ^  ork  \Io«l.  Jour.,  |-VI>.  !>:',.    I'.Ml?.  p.  37!). 

1  John-   I  lopkin-   H<.~pi1;il  Jiullet  in.    I'.i0<>. 

!  uici-i,  Nov.  :;,  i '.MIII. 


TIIK    .T-HAY  1007 

rcct  diagnosis  of  anenrysm.  Radiographs  taken  at  different  times 
showed  marked  variations  in  si/.e  which  could  not  occur  in  a  solid 
growth. 

Guilleminot1  has  even  attempted  to  radiograph  the  aorta  at  differ- 
ent phases  of  the  cardiac  cycle. 

Transposition  of  the  Heart.— This  condition,  suspected  from  the 
physical  signs,  is  verified  by  the  radiograph.  We  may  also  be  enabled  to 
say  whether  it  is  a  congenital  malformation,  as  in  a  case  of  the  author's, 
or  due  to  displacement  by  pleurisy  and  the  like. 

Estimation  of  the  Size  of  the  Heart. — (1)  This  may  be  done  by 
means  of  the  orthodiagraph  (Morit/),  and  a  tracing  made  by  the  pencil 
while  t  he  operator  carries  t  he  cent  ral  ray  around  the  out  line  of  the  heart . 

('2)  Another  method  is  by  t  he  author's  simple  home-made  apparatus, 
p.  !>(.»S. 

('.))  The  orthodiagraph  may  be  used  to  accomplish  the  same  result  of 
orthophotography  (Lepper-Immclmaim)  by  having  a  small  diaphragm 
in  front  of  the  .r-ray  tube  and  carried  with  it.  This  diaphragm  may  be 
in  the  shape  of  a  slit,  adjustable  so  as  to  be  perpendicular  to  the  border 
of  the  heart  at  each  part  to  which  it  is  carried. - 

Tlu1  author's  simple  method  and  Lepper-lmmelmann's  method  both 
accomplish  the  same  result  of  making  a  photographic  record  of  the 
cardiac  area  on  a  sensitized  plate  instead  of  a  pencil  tracing  made  by  the 
operator,  as  in  ordinary  orthodiagraphy.  The  plate,  in  any  case,  should 
be  in  contact  with  the  patient,  and  the  latter  should  not  move  or  turn 
during  1  he  exposure. 

The  I.epper-Immelmann  method  has  the  advantage  over  the  author's 
that  it  enables  the  operator  to  guide  the  beam  of  .r-ray  by  direct  ob- 
servation of  a  fluorescent  screen  placed  behind  the  photographic  plate, 
instead  of  guessing  at  the  area  that  ought  to  be  covered  by  the  moving 
ray  of  liulit. 

The  w.ay  in  which  the  photographic  record  of  the  boundary  of  the 
heart  is  produced  is  explained  in  the  paragraph  on  the  author's  ortho- 
radiograph. 

(h  Simple  radiography  or  fluoroseopy  may  be  employed  to  measure 
the  .-i./c  of  the  heart.  Fluoroseopy,  with  the  tube  at  a  distance  of  2 
meters  isO  inches)  from  the  screen  which  is  placed  directly  in  contact 
with  the  patient,  gives  an  approximation  to  the  actual  si/e  which  is 
close  enough  for  every  practical  purpose.  The  room  should  be  dark- 
ened for  a  few  muiutes  before  the  examination  is  made.  '1  he  screen 
should  be  fastened  in  position  and  have  a  sheet  of  lead  glass  over  it  ' 
to  protect  the  operator.  Tracing-paper  rovers  the  ii'lass,  and  the  opera- 
tor traces  the  outline  of  the  heart  with  a  heavy  graphite  crayon  (a 
packer's  marking  pencil). 

A  radiograph  would  have  to  be  made  at  a  shorter  distance  and  due 
allowance  made  for  magnification. 

Teleradiographv,  with  the  tube  s()  inches  (j2  meter.-)  away,  is  ren- 
dered practicable  by  the  very  powerful  modern  transformers. 

The  transverse  measurement  of  the  normal  shadow  of  the  heart 
compared  to  that  of  chesl  at  same  level  is  10  to  'J  1 . 

Effect  of  Cardiac  Movements  Upon  Rontgen  Ray  Measurements. 

iterfere  wit  h   t  his  niet  hod  of 

v  17.  1 


100S  MKDICAL    KLKCTKiriTY    AND    RO.VHiKN    HAYS 

P<>xi!in/i  ni'  ///(  Patient. — \\here  the  greatest  possible  exactness  i.s 
rei[tiired,  as  in  making  repeated  examinations  of  the  same  patient,  the 
recumbent  position  i-  1  >est  . 

This  position  is  re.-u'ul  to  the  patient,  who  is  compelled  to  hold  still 
during  the  process  of  meii-uration.  Other  advantages  noted  by 
Morit/.1  art1  that  the  respiratory  nioveinenis  are  more  ample  and  the 
heart  acts  more  regularly :  the  diaphragm  occtipies  a  median  position, 
not  being  di-placed  by  the  traction  of  the  weight  of  the  liver  or  by 
the  inte.-tine-:  the  abdominal  wall  is  relaxed. 

The  si/.e  of  the  heart  shadow  is  always  smaller  in  the  upright  posi- 
tion, it  also  descends  in  front  of  the  diaphragm,  and  is  dragged  down 
by  traction  of  the  diaphragm  upon  the  pericardium. 

Sometimes  the  position  is  not  important.  Simple  iluoroscopy, 
with  the  lube  at  a  distance  of  M)  inches,  is  only  practicable  with  the 
pal  icnt  in  an  erect  position. 

The  tube  may  be  in  front  of  or  behind  the  pat  lent,  with  a  slight  pref- 
erence for  the  former  position  when  the  patient  is  erect  as  it  gives  a 
better  view  of  the  vertebra)  and  ribs  and  hence  more  exactly  locates 
the  heart. 

The  tube  should  lie  under  the  patient's  back  when  the  horizontal 
position  is  chosen  for  fluoroscopy. 

Ri«kr'*  M<tho<lj'or  O/'thoradioyraphi/  of  tin-  H<>ni.- — -The  patient  lies 
face  up  on  Morit/'s  horizontal  orthodiagraphic  couch,  the  tube  being 
underneath.  A  tracing  of  the  outline  of  the  heart  and  diaphragm 
is  made  upon  a  sheet  of  paper  held  in  a  horizontal  position  over  the 
patient's  chest;  then,  without  changing  the  position  of  the  patient  or 
<if  the  paper,  a  photographic  film  (Lnmiere  "'Sigma"  or  a  film  made  by 
the  Berlin  Aniline  To.1)  between  two  intensifying  screens  is  slipped 
between  the  patient  and  the  tracing  paper.  The  iris  diaphragm  over 
the  .r-ray  tube  is  cut  down  to  an  aperture  of  only  (\  or  7  millimeters,  and 
the  current  is  airain  turned  on  and  the  orthodiagraphic  pencil  is  again 
slowly  drawn  over  the  tracing  of  the  outline  of  the  heart  and  diaphragm. 
The  thin  bundle  of  ./'-rays,  always  kept  perpendicular  to  the  plane  of  the 
photographic  iilm.  is  carried  around  the  outline  of  the  heart  and  dia- 
phragm. It  makes  a  continuous  series  of  pictures  of  small  portions 
of  the  cardiac  border  which  unite  to  produce  a  single  permanent 
imau'e  upon  the  plate.  The  exposure  required  for  the  final  tracings  is 
thirty  seconds,  with  the  anticathode  at  a  distance  of  2-1  inches  from  the 
iilm.  or  twenty  seconds  at  a  distance  of  Hi  inches.  The  patient  should 
hold  hi-  breath  during  the  time  thai  the  iinal  tracing  is  being  made. 

A  longer  time,  one  or  two  minute-,  \vill  be  required  if  a  photo- 
graphic plate  is  u-ed  in-lead  of  a  film  with  intensifying  screens.  Only 
:i  -mall  par!  of  the  patient  is  exposed  al  a  1  ime.  so  thai  there  is  no  danger 
from  overexposure,  but  it  is  impos.-iblc  for  the  patient  to  hold  his 
for  such  a  length  of  time.  The  image  i-  consei  pienlly  less  clearly 
di  lined  'him  in  t  lie  ot  her  case. 

\    ': .::.    -trip   of   heavy   sheel    lead   i-   placet]   along  the  middle  of  the 
•  -ten mm  to  indicate  1  he  median  line  in  the  image  on  the  photo- 

The  Pulmonary  Lymphatic  Glands. — The  condition  of  the  pul- 
;  .  •  •!-  niav  b<^  studied  b\'  the  .'--rav,  tin1  best  image 


THK    .T-HAY  1009 

being  obtained  with  the  fluoroscope  and  with  a  very  small  diaphragm. 
Scarce!}'  more  than  a  square  inch  of  the  wall  of  the  chest  nearest  1  he  tube 
is  exposed  to  the  .r-ray.  and  the  area  visible  in  the  fluoroscope  is  not 
more  than  2  inches  in  diameter.  Such  a  diaphragm  ma}'  consist  of  a 
couple  of  large  sheets  of  lead,  mounted  in  a  frame  which  can  be  slid  up 
and  down  very  much  like  a  window.  The  arrangement  for  makimr 
the  aperture  larger  or  smaller  may  be  as  simple  or  as  complicated  as  the 
manufacturer  desires.  The  author's  contact  diaphragm  fin  contact 
with  the  ./-ray  tube)  gives  a  larger  field  with  equal  definition. 

An  arrangement  which  affords  excellent  protection  for  operator 
and  patient  besides  enabling  one  to  shift  the  tube  readily  to  an}'  height 
and  change  the  si/e  of  the  diaphragm  at  will  is  described  bv  Albers 
Schonberg.1  The  tube  is  enclosed  in  a  lead  box  of  ample  si/e  fastened 
on  a  pedestal,  which  is  counterbalanced  so  that  it  can  move  freely 
from  one  height  to  another,  and  will  remain  in  any  position  in  which  it 
is  placed.  The  diaphragm  is  a  rotating  lead  disk  with  a  number  of 
holes  of  different  sizes. 

The  arrangement  employed  by  the  author  and  shown  in  Fig.  old  is 
fully  described  on  p.  801.  It  has  the  advantage  of  being  adapted  to 
g<  neral  radiography  and  radiotherapy,  since  the  impervious  tube  box 
can  be  placed  above  or  below  the  operating  table  and  inclined  at  an}' 
angle.  It  is  a  modification  of  Kipperger's  and  Hrickner's  stands. 

According  to  the  post-mortem  studies  of  Pier}'  and  Jacques.-  a  cal- 
careous condition  of  the  glands  indicates  an  old  and  safely  healed  tuber- 
culosis. Sclerotic  spots  make  the  condition  of  a  healed  pulmonary 
tuberculosis  seem  only  probable,  while  cheesy  degeneration  indicates  an 
act  ive  process. 

A  case  radiographed  by  the  author  showed  lungs  filled  with  opaque 
patches,  indicating  sclerosis  of  various  groups  of  lymphatic  gland.-. 
The  case  was  that  of  a  man  about  fort}'  years  old.  with  considerable 
emaciation  and  loss  of  strength,  but  without  pulmonary  symptoms.  A 
physical  examination  by  one  of  our  best  diagnosticians  led  to  the 
report  that  the  lungs  presented  the  signs  of  old  pleuritic  adhesions  with 
probable  tuberculosis.  Another  equally  well-known  physical  exam- 
iner was  perfectly  positive  that  the  patient  did  not  have  tuberculosis. 
The  .r-ray  findings  caused  the  author  to  recommend  a  partial  relaxation 
from  business  sufficient  to  provide  for  a  certain  amount  of  out-ol-door 
exercise.  This  has  been  followed  by  very  great  improvement, 

CulcarrouK  limni-Linl  i/l<i//</x  sometimes  show  more  clearly  on  deep 
inspiration  than  during  expiration. 

Calcified  pulmonary  glands  contrast  quite  sharply  with  the  surround- 
ing lung  l  issue1. 

Abscess  of  the  Lungs. — This  i<  shown  by  the  .r-ray.  no  matter  in 
what  part  it  ma}'  be  located.  An  abscess  presents  an  area  of  opacity 
as  compared  with  the  transhicency  of  the  aerated  tissue  of  the  lung. 
The  outlines  are  clearly  defined,  and  generally  are  more  or  less  regularly 
circular  in  shape. 

The  condition  from  which  abscess  of  the  lung  might  require  to  be 
differentiated  is  in  pyopneuniothorax.  The  .r-ray  findings  in  the  latter 
case  are  that  of  a  small  area  of  lung  at  the  upper  part  of  the  chest  with 
very  much  greater  than  the  normal  density,  an  area  of  almost  total 

iFortsh.  a.  il.  Hob.  .1.  Rocntircn.,  vol.  vii,  No.  3,  April  7,  1904,  149. 

-  Hcvuc  ^-  Mc.i.,  mot;,  Xd.  ft. 

M 


101U  MEDICAL    ELECTKIC1TY    AND    KONTGKN    KAY> 

opacity  at  the  lower  part  of  the  chest,  and  a  larger  or  smaller  area  of  un- 
natural t ranshicency  between  these  two.  In  the  case  of  an  abscess  of 
tiie  lung,  on  the  other  hand,  the  opaque  area  is  usually  surrounded 
by  an  area  of  approximately  normal  translucency. 

l)'iu\  nntin!  Diat/noxin  of  I'Uural  Thickcnituj  ami  Ei'iuxion  and  Pul- 
tr.ntinri/  Abxa.<x. — rieural  thickening  shows  a  less  uniformly  dense 
shadow  than  effusion.  It  is  quite  possible  to  diagnose  a  small  loculated 
effusion  or  empyema  by  means  of  the  x-ray,  which  would  require  many 
exploratory  punctures  to  locate. 

An  abscess-cavity  when  emptied  sometimes  becomes  still  more  evi- 
dent, with  its  thickened  walls  and  unnatural  central  translucency. 

Kmpyema.  whether  loculated  or  not,  presents  a  dense  shadow,  which 
enables  one  to  distinguish  it  from  resolving  pneumonia  with  its  less 
homogeneous  shadow. 

A  case  reported  by  Talley1  showed  what  appeared  in  the  fluoroscopic 
and  skiagraphic  images  to-be  an  empty  abscess  in  the  upper  part,  and  a 
tilled  cavity  in  the  lower  part  of  the  right  side  of  the  chest.  The  autopsy 
showed  that  the  inference  was  correct  in  regard  to  the  empty  cavity 
above,  but  that  the  supposed  filled  abscess-cavity  below  was  in  reality 
a  bronchiectasis  in  which  the  bronchial  tubes  were  filled  with  secretion. 

An  interesting  case  is  reported  by  Anders  and  Pfahler.-  in  which 
tlie  development  of  a  pulmonary  abscess  was  observed  radiographically. 
The  first  radiograph  was  made  three  days  after  the  abscess  had  attained 
its  maximum  size.  It  was  made  with  the  patient  lying  supine,  with  the 
plate  underneath,  and  after  inspiration.  It  showed  an  incomplete 
consolidation  of  the  light  lower  lobe,  with  an  abscess-cavity  about  2 
indies  in  diameter  extending  from  the  upper  border  of  the  fifth  rib, 
posteriorly,  to  the  middle  of  the  second  intercostal  space  in  the  mid- 
scapular  line.  Four  subsequent  radiographs  showed  the  gradual  disap- 
pearance of  consolidation,  the  reduction  of  the  abscess  to  a  cavity  ]  inch 
in  diameter,  and  an  elevation  of  the  diaphragm  to  the  level  of  the  eighth 
rib.  The  latter  was  a  natural  process  assisting  in  obliterating  the  ab- 
scess-cavity. 

liieder  reports  cases  of  abscess  of  the  lungs  in  which  the  radiograph 
.-howed  a  cavity,  in  the  bottom  of  which  fluid  could  be  seen,  which  pro- 
duced waves  when  the  patient  was  shaken.  ]le  thinks  it  important 
in  the  sequela.1  following  pneumonia  to  make  an  ./--ray  examination,  as 
abscess  of  t  he  lumr  seems  to  be  commoner  than  has  previously  been  sup- 

posed. 

ftttrnfho/'ficir  7  amors. —  Juniors  of  the  lung,  usually  met  astatic, 
-how  -harply  defined  dark  areas,  surrounded  by  the  transparent  pul- 
monary tissue.  Enlarged  bronchial  glands  must  be  of  a  quite  consider- 
able size  in  order  to  produce  a  shadow.  Their  shadows  are  sharply 
i  lited,  and  if  they  are  produced  by  peiibrenchial  glands  will  appear 
:i  rrair_red  in  chains. 

MI fi/n.^li/i'il    tmnnrs    can    be    confused   with    aneurysins   only   when 
'.'•.:•    Borders    are    sharp    and    regularly    curved.     If   the   outlines    are 
-  ilar  and  vague,  aneurysins  can  be  excluded.-'1 

'.To-ir.    \:n.  M.-d.  Assoc.,  Sept.  s,  1'iOf,. 

:'\.  .:•  Y.,.-k  Mc.l.  .I-.Mi-..  Autr.  4.  HKKi.  j..  2 ."7. 

•']'•       :  •'••    ;md  Mann.  I  nrtseh.  Geb.  d.  K'.fMt-fn.,  vol.  x,  Xo.  1,  Julv,  !!»()(•. 


mi:  .r-K.\Y  1011 

A'-RAY  DIAGNOSIS   OF   EARLY    PULMONARY   TUBERCULOSIS 

Fluoroscopy.-  Five  important  phenomena  indicate  this  condition 
(Wals.ham  and  Orton) :  (  1 )  Diminished  range  of  motion  of  the  diaphragm 
on  the  affected  side  (Francis  Williams). 

('2)  One  or  both  a]>ices  fail  to  light  up  in  the  fiuoroscopic  image  on 
dee])  inspirat  ion. 

('.)}   The  diseased  part  of  the  lung  casts  a  dark  shadow. 

(-1)  'J'he  heart  is  usually  smaller  and  placed  more  vertically  in  the 
chest. 

(."))  Any  alteration  in  the  shape  of  the  chest  and  position  of  the  ribs 
may  be  better  determined  by  the  .r-ray  than  bv  other  methods. 

1  he  y/Y.s7  sign  is,  perhaps,  due  to  pleuritic  adhesions  and  is  very  fre- 
quently absent  in  recent  cases.  It  is  important  if  present,  but  its  ab- 
sence does  not  exclude  tuberculosis. 

The  *,  cnnd  sign  is  of  very  great  diagnost  ic  value.  The  affected  apex 
may  even  become  darker  during  deep  inspiration. 

The  third  sign  is  of  great  value. 

The /«wr//j  sign  is  the  subject  of  some  doubt.  Bouchard  and  lialt- 
ha/ar  have  found  the  heart  smaller  tlian  normal  in  the  first  and  second 
Mages  of  tuberculosis  and  believe  that  this  acts  as  a  predisposing  cause. 
They  find  that  the  heart  generally  becomes  enlarged  in  the  third  stage  of 
pulmonary  tuberculosis  by  a  compensatory  hypertrophy,  due  to  the 
increased  resistance  in  the  pulmonary  circulation.  It  is  interesting  to 
note  in  this  connection  that  the  heart  has  been  reported  to  be  larger  than 
normal  in  cases  of  healed  tuberculosis. 

The  j'tftli  sign  is  of  value. 

Other  FluoroHCOpic  Signs  of  Earli/  Tuberculosis. — The  condition  of  the 
bronchia]  glands  ma}'  be  studied  with  the  iluoroscope  and  is  especially 
ca.-y  to  determine  with  a  very  small  diaphragm. 

77/r  Caxtol  A')i</lc  ami  the  Functional  A//</l<. — The  measurement  of 
the  costal  angle  is  important.  Measurement  of  the  costal  angle  is 
made  by  noting  the  obliquity  of  one  of  the  ribs  at  the  moment  of  inspira- 
tion or  expiration.  The  functional  angle  is  the  difference  between  these 
t  \vo  degrees  of  obliquity. 

Radiography. — A  radiograph  will  show  the  differences  in  density 
of  parts  of  the  lung,  the  difference  in  the  size  of  the  heart,  and  the 
chan.ues  in  the  position  of  the  ribs  alluded  to  above. 

The  usual  position  is  lying  down,  with  the  plate  under  the  back  and 
the  tube  over  the  chest  and  in  the  median  line.  No  diaphragm  need 
ordinarily  be  used,  but  it  may  be  required  for  an  extremely  accurate 
radiograph,  especially  of  the  apices  of  the  lung-. 

I,'!// / n<i/-<i //]/ ir  Findings  i»  Tnhcmiloxifi  <>i  the  Apt\v  <~>t  tin  Jjniij*. — 
These  have  been  made1  the  subject  of  study  bv  a  great  man}"  observers. 
Adam,  in  connection  with  Albers  Schonberg.'  has  made  use  of  the  com- 
pression  diaphragm,  examining  70  cases,  and  believes  that  this  method 
gives  better  results  than  any  oilier.  (It  requires  a  certain  definite  posi- 
tion to  obtain  the  imatre  of  the  apex  of  the  him:  free  from  the  bone 
shadows.) 

Tt  seems  to  he  impossible  to  get  the  shadow  of  the  apex  of  the 
hi  n  L:  en  t  i  rely  free  from  the  shadows  of  t  lie  bones,  but  a  posit  ion  in  which 
the  plate  is  behind  the  neck  with  the  tub)1  in  front  in  the  median  line 
an  ima^e  which  is  crossed  by  the  shadow.-  of  the  first  and  second 
i  l-'ortseh.  <1.  Cel).  Kurntircn.,  v..].  \.  \V..  :;.  Octoht-r,  r.'Ofi. 


1012  MEDICAL    ELECTRICITY    AND    RONTC.EN    RAYri 

ribs,  but  the  opacity  of  the  apex  of  the  lung  shows  through  the  shadows 
of  these  ribs  as  well  as  through  the  intercostal  space.  The  methoel  is  to 
have  the  patient  lie  on  his  buck  upon  a  wedge-shape'd  cushion,  whose 
upper  surface  makes  an  angle1  of  about  124  decrees  with  the  horizontal 
line.  The  upper  extremity  of  the  cushion  terminates  at  the  level  of 
the  shoulders  and  the  head  can  be  bent  backward  over  it.  The  plate  is 
placed  behind  the  nape  of  the  neck.  A  compression  cylinder,  with  a 
K-i-cm.  diaphragm,  is  so  placed  that  the  rays  pass  in  an  oblique  direc- 
tion from  in  front  upward  and  backward,  covering  an  area  extending 
from  the  lower  part  of  the  larynx  to  the  junction  of  the  manubrium 
and  the  body  of  the  sternum.  Sometimes  the  second,  third,  and  part 
of  the  fourth  intercostal  space  can  be  shown  in  such  a  picture.  A 
moderately  low  degree  of  vacuum  is  used,  and  the  Lumierc  Sigma  plates, 
are  recommended,  with  an  exposure  of  ten  to  fifteen  seconds.  The 
patient  .-hould  hold  his  breath  during  the  exposure,  which  is  preferably 
at  the  moment  of  deepest  inspiration. 

The  normal  lung  shows  shadow  lines  upon  the  plate  which  are 
nearly  at  right  angles  with  the  shadows  of  the  ribs,  and  which  are1  due 
to  the  bronchi  and  their  accompanying  blood-vessels.  If  these  shadows 
are  not  clearly  visible  in  a  good  picture  it  is  an  indication  of  trouble. 
Such  plates  are  apt  to  be  unsuccessful  with  patients  who  have  short  fat 
neck-,  and  also  in  cases  of  kyphosis  or  scoliosis. 

<  >ne  of  their  characteristic  plates  showed  a  cloudy  shadowing  of  the 
whole  second  right  intercostal  space,  with  dark  and  bright  spaces. 
The  third  and  fourth  intercostal  spaces  in  the  same  case  we're  flecked 
with  cloudy  areas.  The  bony  shadows  of  the  ribs  and  clavicle1  were 
altogether  deeper  than  on  the  left  side  and  somewhat  spotted.  On 
the  left  side  there  were  circumscribed  spots  in  the  second  intercostal 


.Mori1  or  less  diffuse1  areas  of  cloudiness  were  found  in  all  cases  where 
the  physical  examination  gave  evidence  of  distinct  dullness.  Cir- 
cumscribed spotting*  were  found  in  cases  where  the  physical  examina- 
tion revealed  only  catarrhal  symptoms,  but  not  in  all  of  these. 

Another  case  showed  decided  spotting  m  the  second  and  third  intcr- 
costaJ  spaces,  though  wit  h  very  lit  t  le  interference  wit  h  the  general  t  rans- 
mission  of  the  .c-ray  through  both  apices.  This,  combined  with  the 
physical  signs,  indicated  a  catarrhal  in  lilt  rat  ion  on  the  left  side,  while1  on 
the  right  side  catarrhal  rales  were  heard  without  any  indication  on  the 
plate. 

Still  a  third  characteristic  plate  showed  two  very  dense  and  sharply 
defined  shadows,  about  twice  the  si/e  of  a  pinhead.  The  contrast  be- 
tween the  rmht  and  left  second  intercostal  spaces  was  sharplv  marked. 
In  the  third,  fourth,  and  part  of  the  fifth  intercostal  space1  there1  was  a 
difference  in  the  general  brightness  of  the  two  sides,  but  here,  where 
so  much  thickness  of  lung  tissue  has  to  be  penetrated,  the1  judgment 
a~  to  whether  the  appearance  is  pathologic  or  not  is  much  more  diflicult 

M  at  the  apex.  The'  general  effect  upon  the  iluoroscopic  se'reen  was 
that  the  left  apex  was  .-mailer  and  more  dense1. 

.  ;.••  plate  showed  a  spotted  cloudiness  in  the  second  left  intercostal 
spaee.  an  evidence  of  some  thickening,  which,  however,  was  not  ex- 
ti'UMve  i  no'iuli  TO  make1  a  difference  in  the  percussion  note.  The1  two 
small  .-harp  .-hadous  were  supposed  to  indicate1  calcification  in  a  caseous 
focus. 


THE    .r-KAY  1013 

The  fourth  characteristic  plate  showed  diffuse  spotting  of  the 
second,  third,  and  fourth  intercostal  spaces,  which  was  also  visible  upon 
the  shadows  of  t  he  clavicle  and  of  t  he  t  hi  I'd  ril>.  The  upper  border  of  the 
clavicle  did  not  seem  sharp.  This  la.-t  feature,  of  course,  was  only  of 
value  when  the  patient  had  held  his  breath  during  the  exposure.  "With 
the  fl Horoscope  the  apex  appeared  cloud}',  while  thickening  was  visible 
in  the  lower  part  of  the  right  lung.  This  plate  showed  that  the  infiltra- 
tion extended  much  lower  than  the  percussion  note  would  have  indicated. 
It  also  shows  that  increase  in  pulmonary  density  is  visible  even  through 
the  ribs. 

The  following  conclusions  are  drawn  from  the  70  cases  which  Albers 
Schonborg  and  Adam  examined  in  this  way: 

An  acute  catarrh  does  not  uive  any  Rontgonographic  evidence, 
but  thickening  of  the  lung  tissue  can  be  discovered  bv  the  ,r-ra\"  before 
it  is  extensive  enough  to  produce  a  change  in  the  percussion  note. 
( 'onsei  jiient  ly.  an  .r-ray  examination  is  desirable  for  cases  in  which  the 
disease  has  progressed  for  some  time  in  the  form  of  chronic  infiltrativc 
processes  of  both  apices  without  catarrhal  symptoms.1 

Shurly-  states  that  the  .r-ray  demonstrates  the  fact  that  pulmonary 
tuberculosis  ma}'  progress  to  the  formation  of  small  cavities  before 
ordinary  skill  in  percussion  and  auscultation  will  detect  it,  and  also 
that  an  .c-ray  examination  at  the  time  of  the  earliest  hemoptysis  or 
fever  will  often  show  much  more  extensive  lesions  than  are  indicated  by 
the  physical  signs.  The  author's  own  cases  corroborate  this  state- 
ment . 

Bonney's  book  on  pulmonary  tuberculosis  contains  excellent  radio- 
graphs illustrating  different  stages  of  tuberculosis. 

Pfahler's  excellent  radiographs  of  cases  of  pulmonary  tuberculosis3 
illustrate  the  different  conditions  revealed  by  the  ./'-ray  in  this  disease. 

A  patient  of  the  author's  had  been  perfectly  well  up  to  three 
months  previously,  when  she  had  a  severe  cold.  This  was  followed  by 
another,  and  since  that  time1  she  had  rapidly  lost  flesh  and  strength 
and  had  frequent  hoinoptyses.  A  radiograph  taken  with  the  author's 
radiating  cellular  diaphragm  showed  the  entire  right  upper  lobe 
clearly  outlined  and  denser  than  am,"  other  part  of  either  lung. 

Ji'ii<i/ni/r<i  fi/iif     (l //t!    l''l uni'usi-i, jin-    /•'///'////,'/*     ///      .  I  i/rdt/ct  (1    1' nl  Jiifitl/lTlJ 

TI.I/H  i'1'ii/oxix. —  Consolidation  is  evidenced  by  a  dark  shadow. 

Cavities  are  seen  as  very  transparent,  circumscribed  areas,  sur- 
rounded by  a  zone  of  opacity  representing  their  thickened  walls. 

Pleuritic  adhesions  are  evidenced  by  diminished  movement  of  the 
diaphragm.  Pleuritic  thickening  is  shown  by  a  slight  shadow,  usually 
wit  hout  di>t  met  border-,  and  pi  omit  if  ei'i'u.-K  <}\  or  empyema  is  shown  by 
u  dee] ).  clearly  defined  shadow. 

Pneuniothorax  shows  a  large  area  of  unnatural  transparency  and  a 
::  n  'a  i  >\  unnaturally  <  ij  >ai  (tie  lung. 

Pyopneuniothorax  is  similar  in  radioirraphic  appearance,  but  with  the 
add  it  ion  of  a  clearly  defined  area  of  dense  <hadow  at  the  most  dependent 

i.  and  this  may  show  wave-motion  when  the  patient  i-  shaken. 

Calcified  foci  in  the  luini  tissue  or  in  the  bronchial  glands  .-how  as 
vi  r  oai  Ue  s  n  it  s. 


1'MM 
I '.til"). 


1014  MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 

The  normal  outline  of  the  pulmonary  vessels  may  be  obscured. 

There  may  be  unnatural  chains  of  opacity  through  the  lung  indicat- 
ing deposits  in  the  bronchial  glands  or  in  the  walls  of  the  bronchi. 

All  these  changes  are  much  more  readily  appreciable  when  the  plate 
is  examined  by  transmitted  light  in  a  negative  examining  box  than  they 
are  in  a  print  made  from  the  plate. 

Radioyraphic  Appearances  in  Healed  Pulmonary  Tuberculosis. — Von 
Jaksch1  has  radiographed  o  such  cases.  One  showed  a  pathologic 
shadow  in  the  upper  part  of  the  right  lung  and  the  left  apex  was  not 
perfect.  There  was  also  a  shadow  on  the  right  side,  close  to  the  spinal 
column,  extending  down  to  the  diaphragm. 

In  another  case  the  radiograph  showed  that  more  or  less  of  the  left 
lung  took  no  active  part  in  respiration. 

Another  case  showed  extensive  calcification  in  the  upper  lobe  of  the 
right  lung. 

Another  case  showed  evidence  of  the  consolidation  of  both  apices. 

Another  case  showed  calcification  in  the  upper  lobe  of  the  left  lung 
very  clearly. 

All  these  cases  had  all  the  regular  symptoms  of  pulmonary  tuber- 
culosis, including  the  presence  of  tubercle  bacilli,  and  had  all  recovered 
from  the  disease  without  the  use  of  tuberculin,  aided  only  by  suitable 
diet.  etc.  At  the  time  of  the  .r-ray  examinations  they  seemed  perfectly 
well  and  the  sputum  contained  no  tubercle  bacilli. 

RADIOGRAPHY  OF   THE  THORAX   IN  PNEUMONIA 

This  will  enable  us  to  recognize  areas  of  consolidation  even  in  the 
central  portions  of  the  lung,  which  are  difficult  to  determine  by  ordinary 
means  of  physical  diagnosis.  It  is  valuable,  both  at  an  early  stage  if  the 
diagnosis  of  pneumonia  is  in  doubt,  and  also  at  a  later  stage  to  determine 
whether  complete  resolution  has  taken  place.  The  therapeutic  value 
of  the  .r-ray  in  the  treatment  of  delayed  resolution  after  pneumonia  ap- 
pears to  be  very  well  established. 

Radiographs  and  fluoroscopic  examinations  show  that  consolidation 
begins  at  the  middle  of  the  affected  lobe  and  extends  to  its  periphery. 
Consolidation  shows  as  increased  density,  and  is  recognizable  by  means 
of  the  .r-ray  before  it  can  be  diagnosed  by  the  physical  signs  or  by  the 
sputum. 

This  examination  shows  the  presence  of  n  nfrnj  pneumonia,  consolida- 
tion which  never  reaches  the  surface,  and  which  is  difficult  or  impossible 
to  diagnose  without  the  .r-ray. 

Riedcr2  reports  in  full  the  histories  of  'JO  cases  of  pneumonia,  fol- 
lowed throughout  their  course1  by  a  series  of  radiographs.  He  uses  a 
medium-soft  tube  and  a  diaphragm  large  enough  to  take  in  both  lungs. 
This  i-  about  the  sixe  of  the  largest  orifice  of  i  he  Friedlander  shield. 
'I  he  thickness  of  the  body  to  be  traversed  makes  it  desirable  to  cut 
down  the  inevitable  development  of  secondary  rays  to  the  lowest  possi- 
ble quantity.  A  diaphragm  aids  in  this  by  eliminating  many  of  the 
secondary  ravs  starting  from  the  walls  of  the  tube. 

Ri'-d'-r  makes  a  drawing  with  a  grease  crayon  on  a  sheet  of  glass 
covering  ihe  ,-urtace  of  the  fluorescent  screen  and  subsequently  transfers 
t  hi-  to  paper. 

1  Fort-Hi.  r,(.l,.  ,1,  Rnrnttfrn., 
i.  Me,!.  WMC!,     N,,s.  2i i 


THK    X-RAY  1015 

An  increase  in  the  sixe  of  an  area  of  consolidation  can  be  discovered 
by  the  .r-ray  earlier  than  by  any  other  method,  increase  in  an  antero- 
postertor  direction  does  not  show  in  an  ordinary  anteropostonor  radio- 
graph and  a  lateral  radiograph  is  usually  impracticable,  liieder  recom- 
mends stereoradiography  in  this  case.  The  different  stages  of  con- 
solidation and  resolution  cannot  be  closely  followed  by  the  x-ray. 
\\  hile  there  is  usually  considerable  reduction  in  the  area  of  opacity  after 
the  crisis,  there  is  often  a  faint  shadow  to  be  seen  long  after  all  the 
physical  signs  have  disappeared. 

I)r>i  j>lcitrix>/  as  a  se<|uela  to  pneumonia  is  evidenced  by  restricted 
movement  of  the  diaphragm,  and  pleurisy  with  effusion  by  a  dark 
shadow. 

Broncho  pneumonia  may  be  easy  or  difficult  to  recognize,  according  to 
the  sixe  of  the  areas  of  consolidation. 

BRONCHIECTASIS 

This  condition  may  sometimes  be  diagnosed  on  account  of  light  areas 
in  the  radiograph  of  the  lung.  The  best  time  to  make  the  exposure  is 
directly  after  a  profuse  expectoration.  An  interesting  case  in  which 
this  condition  of  bronchial  dilatation  was  recognized  by  the  .r-ray  is 
reported  by  Pfeif'fer.1  The  .r-ray  revealed  also  the  presence  of  a  drain- 
age-tube lost  in  the  pleural  cavity  after  an  operation  for  empyema. 

Bronchiectasis  may  be  mistaken  for  abscess  of  the  lung,  as  the 
radiographic  appearances  are  similar. 

FOREIGN  BODIES   IN  THE  LUNG 

Bullets  are  very  easily  located  in  any  part  of  the  chest.  This  may 
be  done  by  means  of  two  radiographs,  one  anteroposterior  and  the  other 
lateral,  or  the  localization  may  be  made  by  the  McKenzie-Davidson 
method.  Among  the  interesting  cases  of  other  foreign  bodies  located 
in  the  lung  is  one  of  a  knife  blade  broken  off  in  the  lung  three  months 
before  the  .r-ray  examination  was  made.  Meanwhile,  symptoms 
similar  to  those  of  advanced  consumption  had  set  in.  The  knife  blade 
was  removed  without  much  difficulty  after  resecting  1  inch  of  an  over- 
lapping rib.  The  case  was  reported  by  Baldwin.2 

Another  interesting  case  is  reported  by  Russell.3  The  patient  was  a 
boy.  twelve  years  old,  who  had  swallowed  a  large  black-headed  pin 
five  weeks  previously,  A  week  or  two  later  there  was  cough  with  blood- 
stained sputum.  Fluoroscopic  examination  showed  the  pin  to  be  lyini: 
in  the  left  lung  with  its  point  upward.  The  foreign  body  was  removed 
through  ;ui  incision  made  into  the  lung.  The  case  is  exceptional,  be- 
cause foreign  bodies  almost  invariably  enter  the  right  bronchus  instead 
of  th''  left .  as  in  this  case, 

]''rau;menis  of  a  peanut  shell,  inhaled,  did  not  show  in  one  of  the 
aut  In  >r  -  cases. 

THE   LUNG   REFLEX 

This  is  a  symptom  which  has  been  de 
it    i 
It  i 


1016  MKDICAL    KLKCTHICITY    AND    KONTf.EN    KAYS 

fnun  a  source  of  cutaneous  irritation  involving  primarily  certain  spots, 
then,  it'  the  irritation  is  severe  enough,  more  remote  pails  may  be  in- 
volveil.  It  can  l>e  excited  in  lungs  showing  diminished  resonance,  the 
resonance  being  ahvays  increased  by  nibbing  the  skin  over  the  lung 
percussed.  It  is  Used  as  a  test  of  the  resiliency  of  the  pulmonary  struc- 
ture. In  the  .r-ray  examination  normal  lungs  present  a  uniformly 
liii'ht  area,  which  appears  brighter  during  inspiration  than  expiration. 
The  increased  translucency  due  to  reflex  lung  dilatation  may  be  observed 
with  the  iiuoro-cope.  It  lasts  for  about  two  and  a  half  minutes.  It  is 
used  in  the  differential  diagnosis  of  lung  dulness  due  to  consolidation  or 
to  atelectasis.  If  the  dulness  is  due  to  at  elect  asis,  as  in  some  cases  of 
bronchial  pneumonia,  cutaneous  stimulation  by  vigorous  friction  or  the 
use  of  cold  water  produces  this  increased  translucency  to  the  .r-ray 
by  expansion  of  the  air-vesicles.  It  does  not  take  place  in  consolidation. 

RADIOSCOPY   OF   THE    ESOPHAGUS 

This  subject   has  been  discussed  on  p.  W\. 

RADIOGRAPHY  OF  THE    3PINE 

This  will  aid  in  the  diagnosis  of  Pott's  disease  if  the  radiograph 
shows  the  presence  of  an  abscess  and  erosion  of  the  body  of  a  vertebra. 
Thi>  examination  in  the  lumbar  region  presents  the  same  difficulties 
and  requires  the  same  technic  as  for  renal  calculi.  It  is  less  difficult 
in  the  upper  dorsal  and  cervical  region.  Vi;r  all  these  parts  of  the  spine 
tli<-  patient  lies  supine  on  the  plate,  while  ihe  tube  is  over  the  median 
line  in  front  at  the  appropriate  level.  The  use  of  a  compression  cylinder 
for  the  lumbar  vertebra'  reduces  the  si/e  of  the  picture,  but  increases  its 
clearness.  The  lower  dorsal  region,  where  the  spine  lies  behind  the 
heart  and  liver,  presents  difficulties  which  ma}'  be  partly  overcome 
by  taking  an  oblique  picture  with  the  tube  in  front  and  to  the  right 
and  the  plate  behind  and  to  the  left.  The  patient  must  hold  his  breath 
during  the  exposure,  which,  therefore,  should  not  last  much  more  than 
thirty  seconds. 

Radiography  of  the  Entire  Length  of  the  Spinal  Column. — 
This  may  be  done,  as  in  one  of  the  author's  cases,  upon  a  glass  plate 
-  \  inches  in  length,  or  upon  a  celluloid  film,  for  instance,  the  Lumiere 
Sm'iua  film,  the  same  sixe,  or  upon  Hontgen  paper,  made  by  the  Xeue 
Photografische  <  iesellschaft,  Berlin-Sticglitz,  whose  agents  in  America 
are  the  Holograph  Company  of  Xew  York.  This  paper  is  about  as 
rapid  as  an  /-ray  plate  and  is  much  more  economic. 

Ihe  pa;  sent  -hould  lie  flat  upon  his  back  upon  the  table,  with  the 
tube  over  the  lower  end  of  the  sternum  and  the  anticathode  2">  inches 
fi  MI  the  plate.  Five-inch  spark  equivalent.  )5()  ma.,  for  fifteen  seconds, 
or  any  other  exposure  of  }.")(>  ma.  second-  for  a  1  "ill-pound  man.  The 
portion  ot  the  -pine  covered  by  the  liver  can  be  seen  oiilv  verv  faintlv, 
|>o--ible  to  trace  the  ueneral  line  of  curvature. 

ithors  contact    diaphragm   make-   it    po-sible  to  secure  good 

definition    in    a    picture   of   thi-   sixe.      It    cuts   out    the   secondary    rays 

;         i  ..  '   01  n  t  he  "Teat er  part  of  i  he  .'--ray  tube  while  permit :  ing  the  direct 

'  •    I  li  rough  a  wide  angle,  and  tin-  causes  increased  deli  nil  ion 

and  coi  •••,-•   it]  t  he  radii  'uraph. 

•    -phial  radiography  does  [)(,i  conn.-!  chieflv  of  iiisiif- 
he  |  ilat  e.    but    in   a    lack   <  >f  <•<  int  ra-t    and   detail. 


TIIK    .r-KAY  1017 

due  to  secondary  rays  original ing  in  the  thick  mass  of  tissue  traversed.' 
This  is  remedied  by  the  use  of  a  diaphragm  cutting  off  the  secondary 
rays  arising  from  the  .r-ray  tube,  which  increases  the  contrast  and 
detail  in  spinal  radiographs  to  a  wonderful  extent. 

Radiography  in  Scoliosis. — An  interesting  observation  lias  been 
made  by  lioehm1  in  regard  to  1  he  etiology  of  this  lateral  curvature  of  tin; 
spine.  Anatomic  study  .-how-  that  it  is  frequentlv  associated  with 
numeric  asymmetries  of  the  spine,  so  that  a  vertebra  lias  a  certain  char- 
acter on  one  side,  while  presenting  on  the  other  side  the  characteristics 
ot  a  vertebra  either  higher  or  lower  in  the  spinal  column.  An  example 
ot  this  is  afforded  in  the  case  of  a  cervical  rib  and  also  in  case  of  atvpic 
sacral  \\mgs.  These  numeric  anomalies  occur  at  the  cervicodorsal, 
dorsoluinbar.  or  lumbosacral  junctions.  Hoehm  found  them  present  in 
17  out  ot  I'll  cases  examined  with  the  .r-ray.  Mspecial  care  is  necessarv 
to  detect  these  conditions,  lie  explains  the  fact  that  scoliosis  does  not 
appear  until  puberty  on  the  ground  that  all  the  vertebra-  are  of  practi- 
cally the  same  type  until  that  time. 

Typhoid  Spine. —  McRae-  reports  a  case  in  which  the  .r-ray  revealed 
definite  changes  in  the  vertebra-.  I)unlop:!  thinks  that  man}'  cases  of 
supposed  typhoid  spine  are  in  reality  cases  of  relaxation  at  the  sacro- 
iliac  articulation.  The  .r-ray  may  enable  one  to  differentiate  between 
these  two  conditions. 

The  changes  reported  by  McIJae  in  a  patient  suffering  from  typhoid 
spine  were  actual  bony  lesions  of  the  spinal  column  itself.  The  .r-ray 
plate  showed  the  presence  of  newly  formed  bone.  He  says  that  not  all 
cases  iif  typhoid  spine  present  such  organic  lesions,  and  some  of  them  are 
po»ibly  functional.4 

Spondylitis  Deformans. — This  is  a  disease  sometimes  of  tubercular 
origin,  and  sometimes  accompanying  syringomyelia  or  other  conditions. 
The  intervertebral  cartilages  become  ossified,  and  this  condition  may 
be  revealed  by  a  radiograph.  The  remaining  lesions  perceptible  by  the 
.r-ray  are  the  rigidity  of  the  spine,  in  a  position  either  of  a  straight 
"poker-back''  or  of  kyphosis,  and  possibly  some  of  the  bony  deposits 
around  all  the  articular  parts  of  the  vertebra1  and  ribs.  Le  Breton3 
reports  cases  in  which  the  .r-ray  was  useful  in  making  a  differential 
diagnosis.  In  a  case  of  my  own  the  ankylosis  was  in  the  cervical  spine 
and  it  \va>  difficult  to  secure  a  favorable  position  ot  the  .r-rav  tube  and 
plate, 

Bullet  Lodged  in  the  Spinal  Canal. — An  interesting  case,  in  which 
a  bullet  passed  through  the  spleen,  stomach,  vertebra1,  and  spinal  cord. 
where  it  was  located  by  the  r-ray  and  removed,  is  reported  by  IVgram.6 
The  pat  lent  recovered, 

THE    ABDOMEN    AND    PELVIS 

A  convenient  method  of  lluoro-copy  i.-  to  have  the  patient  ,-tand 
wMi  hi-  back  toward  the  tube  and  \\ith  the  fluoroscope  in  front.  A 
medium  degree  of  vacuum  (resistance,  '_' '.  inches,  radiometer,  _\o.  o 

'  A  TIL  r>rtlir.|>«-il.  A--I.C.  Annual  Mcctini:.  Auir.  -,  I'.KHi;  Jour.  Am.  M./.l.  A.-.-oc... 
Pert.  (1,  I'.'in1..  p.  soi . 

.  il  Mcrtinir.  A<soc.  «i  Aincr.  I'liy-inan-.   r.'Oti. 
:  \.  V.  Mc.L  J(.\ir.,  Deo.  s,  HUMS. 
'•  !l>i. 1..  May  lY,.  I'.MII'..  p.  l  lot;. 

Ihi-1..  M.-m-h  Hi,  l«)i)7. 
'  Mc.l.  I'm-iTcss.  Jan..  l'.»i>7. 


1018  MEDICAL    ELECTRICITY    AXD    ROXTGEX    RAYS 

Benoist)  and  a  primary  current  of  about  10  amperes'  intensity  No.  10 
Tousey  are  employed,  the  anticathode  being  about  1")  inches  from  the 
surface  of  the  body.  The  size  and  mobility  of  the  liver  and  spleen  can 
be  noted  at  a  glance,  and  so  can  the  presence  of  any  large  dense  mass, 
like  an  appendicular  abscess  or  hydronephrosis.  Gene-rally  speaking, 
however,  pathologic  conditions  in  this  part  of  the  body  require  a  radio- 
graph and  the  fluoroscope  may  be  dispensed  with,  or  if  used  it  had  better 
be  for  a  very  short  time. 

Oxygen  inflation  of  the  peritoneal  cavity  as  for  the  knee-joint  (page 
T074'  has  been  used  by  <).  Goetze,1  Arthur  Stein,  and  William  N.  Stewart2 
preliminary  to  .r-ray  examination  of  the  abdominal  organs. 

Radiography  of  Biliary  Calculi. — Radiography  is  of  value  in  the 
diagnosis  of  gall-stones,  but  this  is  one  of  the  most  difficult  conditions 
in  which  it  is  used.  The  film,  with  an  intensifying  screen,  should 
be  lai  1  upon  a  table,  and  the  patient  may  lie  face  down  upon  it.  A 
film  measuring  about  14  x  17  inches  should  be  used,  and  this  is  placed 
so  that  its  -center  is  at  the  umbilicus.  The  tube  is  placed  vertically 
above  the  center  of  the  plate,  the  distance  from  the  anticathode 
to  the  plate  being  23  inches;  4-inch  back-up  and  30  ma.  for  thirteen 
seconds  or  any  other  390  ma.  seconds  would  be  suitable1  for  a  man 
weighing  about  150  pounds.  Two  intensifying  screens,  two  thicknesses 
of  tin  to  obstruct  secondary  .r-rays  arising  in  the  tissues;  o-inch  back-up 
and  30  ma.  for  thirteen  seconds  is  the  author's  improved  technic.  The 
difficulty  is  that  some  biliary  calculi  present  very  little  resistance  to  the 
passage  of  the1  .r-ray  and  show  no  contrast  with  the  surrounding  tissues. 
The  stomach  and  intestines  should  be  empty.  By  this  method  the 
anterior  extremities  of  the  ribs  are  shown  more  clearly  than  any  other 
bony  structures,  but  by  the  dorsal  method  the  vertebra?  and  posterior 
extremities  of  the  ribs  ought  also  to  show  very  well.  The  Eastman 
duplitized  film  is  suitable. 

Gall-stones  present  a  resistance  to  the  passage  of  the  .r-ray  that  is 
very  slightly  different  from  that  of  the  abdominal  tissues.  A  gall-stone, 
|  inch  in  diameter,  held  in  the  closed  hand,  can  be  traced  in  a  radio- 
graph, but  with  difficulty,  not  at  all  like  a  bullet  or  piece  of  glass. 
Nevertheless,  a  mass  of  gall-stones  in  the  gall-bladder  presents  a 
shadow,  though  not  so  dense  as  a  solid  tumor  or  anv  other  solid  mass 
would  present,  if  surrounded  to  some  extent  by  the  translucent  gaseous 
content-  of  the  intestines.  This  shadow  t  Inns  out  at  the  edges  where  the 
./•-ray  [Kisses  through  only  a  small  thickness  of  calculus  material  and  its 
out  hues  mav  be  verv  vague  indeed.  The  cent  ral  port  ion  of  the  shadow, 
due  to  the  thicke-t  portion  of  the  mass,  may  be  moderately  dense,  and 
Mill  the  Imht  and  shadows  of  this  part  of  the  abdomen  may  disguise  it 
or  normal  shadow^  mav  simulate  this.  A  plate  like  this  requires  long 
development,  and  trifling  inequalities  in  the  sensitiveness  of  the  film 
mav  produce  ;m  apparent  shadow  where  one  does  not  really  exist. 

Imperfections  in  the  plate  present  the  appearance  of  shadows  or 
iften  of  increased  transparency.  Misinterpretation  of  the  spots 
i-  avoided  bv  using  two  plates,  one  under  the  other.  A  spot 
hows  on  both  plates  is  presumably  due  to  conditions  in  the 
it  the  patient,  and  a  spot  which  shows  on  only  one  of  the  plates 
umably  due  to  an  imperfection  in  that  particular  plate. 

A  rat  her  la  rin-  shadow,  with  vague  out  lines  m  t  he  gall-bladder  region, 

Munch,   Mirrl.   \\orl,.,   Xovcmhir  ]'_',    Mils. 

M'"l.  Sir.  County  of  New  York.  <  >ctnb<-r 'J7,  MM'.). 


THK    X-KAY  1010 

may  be  stated  to  he  compatible  with  the  existence  of  a  mass  of  gall- 
stones. It  is  always  extremely  difficult  to  say  positively  that  gall- 
stones exist.  Some  eases,  like  one  diagnosed  1>\-  the  author,  p.  KHil, 
present  clinical  symptoms  suggest  ive  of  gall-stones,  but  if  the  radio- 
graphic  shadow  is  as  dense  at  the  periphery  as  at  the  center,  and  if  the 
borders  are  sharply  defined,  it  may  be  staled  that  it  is  not  due  to  a  mass 
of  gall-stones.  In  the  case  referred  to  the  mass  was  due  to  hvdro- 
nephrosis. 

The  most  that  the  radiographer  ought  to  say  is  that  the  radiograph 
is  or  is  not  the  kind  of  one  that  would  be  produced  by  gall-stones. 

In  making  the  radiograph  the  plate  may  be  placed  upon  the  table 
and  the  patient  lie  upon  it.  either  supine,  with  the  plate  over  the  middle 
of  the  abdomen  at  a  considerable  distance,  at  least  23  inches  from  the 
plate,  or  prone,  with  the  tube  over  the  back,  at  a  distance  of  at  least  23 
inches  from  the  plate. 

The  xi<pine  /xtxition  gives  a  better  image  of  the  spine,  but  the  gall- 
bladder is  as  far  as  possible  from  the  plate,  and  its  image  is,  therefore, 
magnified  and  indistinct.  Any  kind  of  compression  is  helpful  in  this 
regard.  A  thin  rubber  bladder  made  for  the  air-container  in  a  foot-ball 
may  be  about  half  filled  with  air  and  placed  over  the  gall-bladder 
region.  It  may  be  pressed  down  by  bandages  passed  over  the  abdomen 
and  pulled  tight  to  each  side  of  the  table,  or  the  rubber  air-bag  may  be 
compressed  by  the  author's  board  compressor.  The  board  compressor 
alone  is  not  very  useful  for  these  cases,  because  the  portion  to  be  com- 
pressed is  close  to  the  ribs. 

Albers  Schonberg's  compression-cylinder  may  be  used  for  the  same 
purpose.  It  gives  a  clear  image  of  the  spine,  and  as  clear  an  image 
of  the  gall-bladder  as  either  of  the  other  means  of  compression,  but  it 
gives  only  a  small  picture,  not  over  S  inches  in  diameter. 

In  the  prone  position,  with  the  tube  over  the  back,  the  element  of 
compression  may  be  obtained  by  laying  an  SX  10-inch  plate  upon  a 
book  or  piece  of  wood  the  same  size  and  putting  it  under  the  abdomen, 
or  the  rubber  air-bag  may  be  placed  on  top  of  the  plate  and  under 
the  abdomen,  but  this  has  the  disadvantage  of  keeping  the  part  to 
be  radiographed  away  from  the  plate.  This  offsets  the  advantage 
gained  by  reducing  the  thickness  of  tissue  to  be  traversed  by  the  x-ray. 
The  board  compressor  (Fig.  73"))  is  useful  to  immobilize  the  patient. 
and  produces  compression  in  a  corpulent  person  to  effect  a  reduction 
of  an  inch  or  more  in  the  thickness  of  tissue  The  compression  cylin- 
der accomplishes  the  same  result  as  the  board  compressor,  with  the 
added  clearness  resulting  from  cutting  off  the  secondary  rays,  but  with 
the  disadvantage  that  the  picture  is  a  small  one. 

Heck1  suggests  that  the  patient  lie  face  down  upon  the  plate,  with  a 
piilnw  under  the  symphysis,  pubis  and  another  under  the  sternum  to 
allnw  of  protrusion  of  the  gall-bladder  region.  He  has  the  patient  lie 
somewhat  on  his  right  side  and  ha.-  the  x-ray  tube  still  further  to  the 
right,  so  that  the  rays,  make  an  angle  of  -15  degrees  with  the  plate. 

A  radiograph  of  a  case  of  suspected  biliary  calculi  may  be  made 
-implv  of  the  gall-bladder  region,  and  then  a  compression-cylinder  or 
-nine  similar  apparatus,  like  a  protective  shield,  may  be  used  to  limit 
the  rays  of  this  particular  part  and  cut  off  the  secondary  rays.  The 
radiograph  will  be  a  small  one  with  excellent  detail,  which  will  answei 
the  <nie.-tion  as  to  the  condition  of  the  gall-bladder,  but  it  does  not 
1  N.  Y.  Mr.l.  Journal.  .Ian.  I'll.  I'.tOO. 


1020 


MF.OH  AI.  Ki.F.t  TKniTY  AND  KONTGEN  KAYS 


take  in  the  other  kidney,  the  ureters,  and  bladder,  which  are  often 
under  >ii>picion  in  the-e  cases. 

A  radiograph  upon  a  11  •  17-inch  plate  takes  in  all  of  these  regions, 
and  it  is  po<>ible  to  get  excellent  detail  upon  it. 

Radiographs  which  -eeined  to  siio\v  the  presence  oi'  gall-stones  sub- 
(jueiitlv  removed  by  operation  have  I  teen  published  by  Heck. 

Tn'o  f'a.sv.v  Ejctnniiuil  for  Xu*i>(Ctnl  {-lilittri/  Calculi. — The  radio- 
•i'raphic  tindiim-  in  these  2  cases  are  instructive.  Kadi  patient,  brought 


outrla^.  had   a    palpable  -\vellin<>;  in   the  region 


add'-r   and    had    pain    and    othei    ^yinploins   su<r(re<tive   of 


/,'.//!«/•/  on  tn>    T'l-n  !;,,,!  ,»/,•-;/-',•  M,,,!,  of  the  First  Case. 

I'd    a    V.'tLlMe   a!i.:    -I    npadly.   extending  down 

-  '  '    -id'  •-•          •  -[tine,  which  corresponded 
•il   a   collection  of  u'all- 

Tiie-e   have   a    d'-n-i  •   de-ree  ,  ,f  opacity  to  the 

lli«  '    do  1'iot  ? 


THK  .r-HAV  1021 

picture,  taken  \viih  the  stomach  and  intestines  cut  in-lv  <  mpty.  .-hows 
that  the}-  were  fecal  in  nature. 

"The  second  picture  showed  tlic  same  vaguely  defined  shadow  below 
the  liver  region,  obscuring  the  image  of  the  ribs  on  that  side,  \vhile 
those  on  the  other  side  arc  quite  plainly  visible. 

"The  conclusions  to  be  drawn  from  these  two  pictures  are,  in  the 
first  place,  that  there  is  no  renal,  uretcral,  or  ve.-ical  calculus  present, 
and.  in  the  second  place,  the  picture  exactly  corresponds  to  that  which 
would  be  found  in  a  patient  with  a  collection  of  gall-stones  and  without 
an}'  "Teat  amount  of  fluid  in  the  gall-bladder.  It  cannot  be  stated 
positively  that  gall-stones  are  pre.-ent,  but  it  seems  probable." 

A  collection  of  gall-stones  were  found  v\  hen  the  operation  va- 
performed. 

The  Autttor'x  Report  on  the  Tim  R<i<U<><jrtipls  Made  of  the  Scrond 
Patient. — To  avoid  repetition  the  reader  is  referred  to  p.  1002.  on  which 
this  report  is  to  be  found.  The  radiograph  showed  that  the  case  was 
not  one  of  gall-stones,  but  probably  of  encysted  fluid.  An  operation 
showed  the  correctness  of  this  interpretation;  the  fluid  being-  due  to 
hydronephrosis. 

Hepatic  Abscess. — A  case  in  which  this  disease  simulated  pulmon- 
ary tuberculosis  and  in  which  the  ;r-ray  revealed  the  true  condition  is 
reported  by  Quadrone.1 

THE   STOMACH  AND   INTESTINES 

In  all  radiographs  through  the  abdomen  and  pelvis,  the  bowels 
should  be  thoroughly  emptied  and  no  solid  food  or  milk,  which  form- 
opaque  coagula,  should  be  taken  for  twelve  hours  previously.  In 
many  radiographs  the  course  of  the  colon  and  different  other  parts  of 
the  in  test  uies  may  be  recognize*  1.  the  air-filled  portions  being  more  trans- 
parent t  han  the  rest . 

The  bc*t  position  is  with  the  patient  standing  with  the  .r-ray  tube 
behind  at  the  level  of  the  umbilicus  and  with  the  plate  in  front. 

The  si/e,  shape,  and  position  oi  the  stomach  may  lie  determined  by 
makinir  a  radiograph  with  an  emulsion  of  bismuth,  oxychlorid  or  -ul>- 
earbonate.  or  of  barium  sulphate  (specially  purified  tor  radiology),  or 
of  black  oxid  of  iron,  which  is  less  satisfactory,  or  of  zirconium  o\id 
i  "( 'out  rast  in."  introduced  by  Kaestler  .~  It  requires  two  to  tour  time- 
the  dost1  of  bismuth  in  the  stomach.  This  can  be  introduced  into  the 
stomach  and  subsequently  withdrawn  through  a  tube,  and  i-  quite 
harmless,  even  if  swallowed  in  the  ordinary  way.  The  radiograph 
may  be  made  with  the  patient  lying  either  face  down  upon  the  plate  or 
face  up.  or  with  the  patient  standing  and  the  plate  in  front.  Distance 
from  atiticathode  to  plate  2o  inches,  back-up  -park  ~)  inches,  intensifying 
screen,  :>0  ma.  for  four  second-,  or  any  other  120  ma.  second  exposure  for 
a  loO-pound  man  of  average  wai-t  and  hip  measurement-.  The  exposure 
inu-t  be  irreatly  varied  according  to  -ex.  weight,  and  measurements 
(see  Kxposure  Table,  page  S'.tS'.  Fora  very  -tout  patient  the  distance 
should  lie  increased.  Kxposure  should  always  be  made  as  short  a-  po— 
sible  b  the  use  of  the  be.-t  inten-il'inu'  screen.  Thi-  i-  to  pi-event 


1(122  MKlUfAI.    1.1. Kt   IHKHY     AND    KOXTUKN     HAYS 

give  a  full  expo-ure  in  a  small  fraction  of  a  second.  The  different 
transformers  ami  the  unfluctuating  convener  will  do  this  in  one- 
quarter  -econd  or.  with  anything  like  the  maximum  power,  in  a  much 
,-horter  time.  With  the  patient  lying  supine  upon  the  plate  the 
radiograph  -hould  -how  all  the  vertebra-,  their  bodies,  and  transverse 
proce--e-.  Foreign  bodies  in  the  alimentary  canal,  or  in  the  bladder, 
or  in  the  ti>sues  of  the  abdomen  are  located  by  the  same  kind  of  a 
radiograph.  The  progre.—  of  a  mass  of  food  and  metallic  emulsion 
through  the  alimentary  canal  can  be  studied  in  successive-  radio- 
graph-, but  owing  to  the  cumulative  effect  of  the  .c-ray  a  limited 
number  would  lie  desirable  in  the  human  subject. 

l'ancoa-t  ha-  -ecu  poisonous  effects  from  leaving  large  quantities 
of  bismuth  -ubnitrate  in  the  stomach,  and  advises  removing  it  with  a 
stomach-tube  as  -oon  a-  possible  if  over  an  ounce  has  been  swallowed. 

Made'-  Mildest ed.  in  Is'.t't.  tilling  the  stomach  with  "'as  in  order  to 
-ecure  a  radiograph  showing  its  si/.e.  sha]>e.  and  position.  He  swallowed 
-ome  Seidlit/  powder  and  had  a  radiograph  made  of  his  stomach,  which 
wa-  better  than  any  pictures  obtainable  up  to  that  time  by  administering 
opaque  substances. 

( 'ole  and  Finhonr  revived  this  practice,  but  it  has  proved  less  useful 
than  the  other  method. 

1'fat'f  and  Nelsoir1  have  made  GO  fluoroscopic  studies  of  the  effect  of 
laxative-  upon  peristalsis.  In  cats,  after  the  ingest  ion  of  food  mixed 
with  bi-muth.  peristalsis  could  be  readily  watched. 

Dangers  from  the  Ingestion  of  Bismuth  Subnitrate  and  Desir- 
able Substances  for  It.-  From  1  to  2  or  even  4  ounces  of  bismuth 
.-ubnitrate  max'  be  required,  and  if  then-  is  a  deficiency  of  hydrochloric 
arid  a  quantity  of  nitrites  may  be  produced.  Two  or  more  deaths  and 
-e\  eral  cases  of  dangerous  depression  have  occurred  which  are  attributed 
to  t  hi-  react  ion. 

Bi-muth  subcarbonate  is  thought  to  be  perfectly  safe  in  doses  of  1 
or  2  or  even  ~>  ounce-,  but  bismuth  oxychlorid  is  still  better  in  the  same 
doses,  brcau-e  it  doe-  not  excite  any  reaction  in  the  -tomach.  Bismuth 
oxychlorid'  doe-  not  relax  the  pylorus  sooner  than  natural  food  and  does 
ii"i  cause  constipation.  It  may  be  given  well  stirred  up  in  a  bowl  of 

•d  and  milk. 

The  Bismuth  Meal.-  A  convenient  formula  is  a  portion  of  mashed 
p"iato  with  '_'  or  more  ounces  of  bismuth  oxychlorid  and  a  glass  of 
.vat i-r.  A n «'i  her  excellent  one  i-  von  ( iourevitsch's  potato-flour  decoc- 
bi-mutlr'.  employed  by  the  presenl  author.  An  ounce  of 
p"tato  fl"ur.  '  ounce  of  almond  -yrup.  G  ounce-  of  milk,  and  I1,  ounces 
uth  o\ychlond  are  thoroughly  mixed  and  poured  into  (.)  ounce-' 


1023 


are  not  so  good  as  with  bismuth.  The  metallic  powder  i-  mixed  with 
mashed  potato. 

litirinni  xiil/tlidtc  and  fermillac.  a  sour-milk  preparation  of  aur<-eable 
taste  and  consistency,  form  the  most  generally  satisfactory  radingraphic 
meal. 

Gastric  Findings  with  the  Rontgen  Ray.  An  increa-e  in  the  vertical 
length  oi  the  stomach  is  seen  in  cases  of  gustroptosis  and  cntcroptosis, 
and  anything  which  cause-  a  loss  of  the  fatty  layer  in  the  abdomen; 


thu>  it  nriv  be  seen  after  t  he  Weir  M  it  chell  t  reatment ;  and  the  stomach 
mav  -how  increased  motility  on  change  ot  po-ture  or  pressure. 

Dilatation  of  the  stomach  occurs  chieily  in  pyloric  ob>t  ruction  by 
cancer  or  by  adhesion  following  perforating  ulcers  ot  ;  he  pylorus  or 
duodenum  Fig.  Til1.  The  outline  of  the  stomach  with  its  bismuth  meal 


1 1  r_M 


MKDIi'AI. 


is  clear  and  sharp  in  these  cases  even  when  the  patient  is  recumbent. 
The  cases  in  which  dilatation  i-  atonic  and  not  obstructive  show  in  the 
recumbent  portion  an  indi-iiiict  outline.  The  shadow  is  that  of  a  pool 
of  dense  liquid  deep  and  opaque  iii  the  middle,  but  shallow  and  increas- 
ingly transparent  near  the  edges. 

(  luiii'its  in  l-'tin/i.  One  of  these  is  the  hour-gla--  contraction  (Fig. 
7 1'J  .due  sometime-  to  cicatrieial  coniraction  after  ulcer,  or  to  pcrigas- 
tritis  with  adhesions,  or  to  carcinoma.  It  i.-  sometime-  spasmodic  in 
cases  of  gastric  ulcer.  Circumscribed  defects  in  the  outline  of  the  bis- 
muth shadow  oi  the  stomach  indicate  pressure  trom  without  or  caused 
by  the  growth  oi  a  tumor  m  the  wall  of  the  stomach. 

CliatujtK  in  Mnt/lili/.-  IVri-tal-i-  and  changes  of  position,  produced 
by  normal  pressure  or  by  change  of  posture,  may  be  studied  with  the 


•ope  or  I  iy  me; m-  of  a  -cries  of  ra.dioiiraph-  eit  her  cinematographic 

4    !i  .nirer  interval-. 

I  he  [engt  h  ot  !/>//>  thul  {<><>< I  in  r<  hi / m  <l  in  lit  xtnHtdch  is  of  1  he  greatest 
f'taiice.aiid  c;in  be  better  and  moi'e  safely  determined  by  a  series 

•  irraphs  than  by  fiuorosciijjy.      In  a   state  of  health   the  bismuth 

let'   the  -toinacli  in  two  or  three  hour-.      A-  -hort  a  time  as 

•  •.'  n  hour-  i-  -on i ei  m ie-  found   in  hyperacidity  and  a Iso  sometimes 

ifiiciency:    in    the    latter    the    -tomach  emptie-  itself  more 
1  'at  icn'   lie-  upi  in  hi-  riuht 

u-uallv   made  -i\   hour-  after  a   bi-mulh  meal,  and 

'•etention    thi-    may   indicate  atony  or  pyloric  obstruction. 

!  ;e  to  caiicer  or  perforated  ulcer-  \\iih  adhesions.     In 

1     the  author  by    I  )]'.    l!obert    <    .    l\.  mp   fully   half  of  the 


'I  I  IK    X-RAY 

meal  was  found  in  the  -toinach  six  and  eight  hour.-  later.  The  -tomach 
was  large  and  extended  vert  irally  downward  on  the  left  .-ide.  At  the 
operation  there  were  found  perforated  ulcers  of  the  pyloru-  and  duo- 
denum, wit h  adhesions  to  the  pancreas,  colon,  and  every  nemhbonnu 
tissue.  Twelve  hours,  uiul  even  twenty-four  hours,  retention  occur  in 
the  worst  cases  of  pyloric  or  duodenal  stenosis. 

Schlesinger's1  intermediate  layer  shows  as  a  horizontal  !>and  lietween 
the  shadow  ol  the  bismuth  meal  and  that  ot  the  magcn-blase.  It  r- 
supposed  to  vary  in  width  and  quickness  of  formation  with  the  amount 
of  acidity.  It  would  lie  prominent  in  ulcer  and  ab.-ent  in  cancer.  It  i- 
prominent  in  catarrhal  gastritis. 

(idxtrir  ilctr  tx-h'<i;/  I)/<i<jr/</.-</xi.  A  case  of  hypersecret  ion  examined 
for  1  )r.  Kemj)  had  had  sick  headaches  from  the  time  he  was  seven  yeans 
old.  and  there  had  been  regurgitatioil  of  hile  and  ga>tric  juice  po--ibly 
containing  pancreatic  juice.  This  condition  had  been  only  temporarily 
relieved  by  an  operation  upon  the  gall-bladder.  The  patient  would  go 
to  bed  after  having  the  stomach  emptied  liy  a  stomach-tube,  and  on 
aspiration  the  following  morning,  before  taking  any  food  or  drink,  the 
stomach  would  be  found  to  contain  a  pint  or  more  of  gastric  juice  contain- 
ing neither  visible  or  occult  blood.  The  fluorosoope,  after  a  bismuth 
meal,  showed  that  the  stomach  was  in  a  vertical  position,  large  and  flac- 
cid and  with  sluggish  peristalsis.  A  radiograph  made  three  and  one-half 
hours  later  showed  an  irregular  spot  of  bismuth  adherent  to  the  wall  of 
the  stomach  near  the  cardiac  orifice.  The  rest  of  the  bismuth  was  in 
the  last  part  of  the  small  in  test  i  ne  and  in  the  ascending  colon.  A  diagno- 
sis of  ulcer  of  the  stomach  was  followed  by  appropriate  treatment  and 
cure. 

Difference  in  Appectrcince  Between  (  leer  and  Cancer  of  tin  Stomach. — 
The  n/cli<'  xi/tH/itoni  ( "Xischensymptom"  in  (iermaii*  is  characteristic  of 
perforating  ulcer  and  may  occur  in  any  ulcer.  It  mean-  that  a  radio- 
graph taken  shortly  alter  a  bismuth  meal  .-how-  a  certain  spot  oi  great 
density  where  the  bismuth  extends  into  a  cavity,  and  there  i-  often  a 
lariie  maiden-blase  and  a  marked  intermediate  layer.  If  the  ulcer  i-  at 
either  curvature,  the  shadow  may  project  beyond  the  uvneral  outline. 

When  there  is  a  niche  it  usually  protrudes  from  the  lesser  curvature, 
and  it  has  been  observed  to  become  obliterated  Hi  the  course  ol  ap- 
pn  ipriate  t  reat  ment  .- 

(  'an  cei'.  on  t  he  other  hand,  cut  -  out  a  port  ion  oi  the  bismuth  shadow 
of  the  stomach  and  is  often  failing  in  an  intermediate  layer. 

M.  Hatldek'  note-  the  following  differential  points  between  gastric 
ulcer  and  cancer:  I  leer  is  apt  to  cause  pyloric  spasin  and  retard  empty- 
ing oi  t  he -tomach :  the  outline  ot  the  stomach  shadow  is  smooth;  can- 
cel' at  an  early  stage  cause-  gaping  of  t  he  pyloru-,  and  later  may  produce 
stenosis  with  greatly  prolonged  retention  of  the  bi-muth  meal  in  the 
stomach:  cancer  produces  a  jagged  outline  of  the  -hadow. 

I'titifiiltilitif  nj  If  ejection  ni  (iiixtrn'  (  urci  itoHin  Indicated  )>>i  tic  l-{<idi<>- 
</ri;/>h.  The  more  favoral)le  cases  are  those  in  which  the  fish-hook  out- 
line ol  the  lesser  curvature  and  pvlorus  are  retained. 

Radiography    in    Intestinal    Obstruction.-  . I u-t    as    in    the 

:  Schlcsinfior,  V.\i\<*  Aciditatsbcstirntniiiiy  dc-  M.Mirciimhalt 
vi-rt'.-dirrns.  N'rrcin-liiTichi ,  Mcd.  Kiinik.  I'.Ml.  S.  (.i.">u. 

Walter  \\  .   Ihiinliur-icr,   Amcr.  Jour.   Mcd.  Sri.,  vol.  civ. 
tUK  n.  '-'01. 

\\cin.  klin.  Woch..  .January  11.  I'.Ml',  \\v.  12.  p.  f.7. 


ll)2t)  MEDICAL    EI.Ki  TKiriTY    AND    KOXTCEN    HAYS 

stricture  of  the  esophagus  a  bolu-  of  metallic  emul-ion  will  show  in 
a  radiograph  of  the  abdomen,  and  its  position  a  certain  number  of 
hours  or  days  after  its  intre-tion  will  indicate  the  site  of  an  intestinal 
obstruction.  In  a  case  reported  by  Kinhorn1  130  gr.  of  bismuth  sub- 
nitrate  in  a  pint  of  milk  were  swallowed.  The  radiograph,  taken 
twenty-four  hour-  later,  -howed  a  dense  mass  filling  a  part  of  the  in- 
te.-tines.  then  a  contracted  portion  where  there  wa>  no  bismuth,  and  a 
portion  beyond  that  wa-  filled  with  it.  The  location  was  thought  to 
be  in  the  lartre  inte-tine,  and  to  test  this  matter  another  radiograph 
wa-  made  five  day-  later,  after  the  original  amount  of  bismuth  had  all 
been  pa>-ed.  Before  making  the  radiograph  '.->()  gr.  of  bismuth  in 
odd  cc.  of  water  had  been  injected  into  the  rectum.  The  same  radio- 
graphic  appearances  were  found  and.  as  it  was  extremely  unlikely  that 
the  injection  had  pa-.-ed  beyond  the  ileocecal  valve,  it  was  regarded  as 
quite  po-itive  that  the  -tricture  was  in  the  large  inte.-tine. 

Radiography  of  Intestinal  Adhesions.-  A  case  <  Fig.  711)  examined 
by  the  author  for  I  )r.  Robert  ( '.  Kemp  suffered  greatly  from  constipa- 
tion, attributed  to  adhesions  following  one  or  two  operations  upon  the 
pelvic  organ.-.  The  symptom-  pointed  to  the  >ignmid  flexure  or  the 
rectum  as  the  seat  of  obstruction:  but  the  picture,  after  a  bismuth 
enema,  -howed  that  while  theentire  large  intestine  was  in  normal  position 
and  permeable  to  the  injection  an  almost  empty  region  remained  in  the 
tran-ver-e  colon.  The  injection  distended  the  parts  on  both  sides.  It 
-eemed  a-  if  tlii.-  condition  could  only  be  accounted  for  by  pressure  either 
from  a  tumor,  which  could  be  excluded,  or  from  a  band  of  adhesions. 
1  he  latter  wa-  found  at  operation. 

'1  he  n  cun/fii  nt  jx>.^it  inn .  the  patient  lying  upon  his  back  with  the 
plate  underneath.  i>  often  used  by  the  author,  because  displacement  of 
the  -tomach  and  inte-tine  which  are  not  corrected  by  this  position  are 
u-ually  rendered  permanent  by  adhesions. 

The  Duodenum.-  Radiographs,  as  a  rule,  do  not  show  this  part  of 
the  inte-tine  at  all.  or  only  a>  a  -hadowy  outline,  making  a  curve  around 
the  pylorus  with  its  concavity  toward  the  left.  Kinhorn's  method  of 
blocking  1  he  duodenum  by  inflating  a  rubber  ball,  passed  into  the  duo- 
denum by  an  esophageal  boutiie.  gives  an  excellent  picture  of  the  duode- 
num when  succes.-fully  accomplished,  and.  of  course,  the  rare  cases  of 
-t(  no-i-  of  the  duodenum  from  cancer  or  ulcer  also  cause  it  to  show  in  the 
radiograph.  'I  he  bulbils  duoden  or  cap  may  show  as  a  dense  shadow, 
-eparated  from  that  of  the  -tomach  by  the  clear  space  of  the  pylorus 
wit  h<  iiit  indicai  iim  any  le-ioii. 

In  Mime  ot  the  author-  ca-e-  a  -mall  dense  -hadow  has  been  seen 
ai  one  part  ot  the  duodenum  -ix  hour-  alter  the  ingest  ion  of  a  bismuth 
meal,  and  thi-.  combined  with  the  symptomatology,  has  been  taken  as 
indicating  duodenal  ulcer:  and  tin-  diagnosis  has  been  confirmed  in 
'  '  •  ca-e-  which  have  been  operated  on.  Six  hour-  after  a  meal  t  he  bis- 
-  commonly  to  be  -een  far  down  in  the  pelvis  or  low  down  on  the 
1  ither  m  the  la-1  part  i  it  the  small  inle-tme  or  in  the  cecum 
-cendiim  colon.  'I  hi-  tact  make-  any  -eparalc  -hadow  at  that  time 
to  the  median  line,  and  near  the  second  or  third  lumbar  vertebra1, 

c.'  >U-    ot    i  him  lejial    ulcer. 

•  rity  of   ca-e-  no  particular  information  in   regard  to  the 
;-  obtained  in  t  he  r-ray  dia trim-is;  but .  of  course,  anv 
b-iruction   from  any  cau-e  would   be  -hown   bv  the  arrest 
'•  N    V    MI -I    .Inurn.,  Mav  1--.  ion; 


THE    .r-KAY  1027 

of  the  bismuth  meal  ;it  tliat  point.  Lane's  kink  may  be  revealed  in 
this  way. 

The  appendix  is  sometimes  to  be  seen  in  radiographs  made  after 
a  bismuth  meal,  or  after  an  injection  of  bismuth  or  barium.  The  fact 
that  it  is  visible  does  not  indicate  any  lesion. 

The  colon  is  usually  best  studied  from  a  radiograph  made  after  a 
rectal  injection  of  about  2  pints  of  a  liquid  holding  in  suspension  barium 
sulphate  or  bismuth  oxychlorid. 

Barium  sulphate .  . 

Bolus  alba 

Water.  . 


Such  an  injection  fills  every  part  of  the  large  intestine  from  the 
anus  to  the  ileocecal  valve,  and  some  of  the  author's  radiographs  show 
that  even  this  is  sometimes  passed. 

Normally,  the  colon  forms  a  sort  of  letter  H,  with  the  splenic  flexure 
reaching  far  up  under  the  ribs;  the  hepatic  flexure,  extending  not  quite 
so  high,  but  still  well  above  the  level  of  the  umbilicus;  the  transverse 
colon  at  about  the  level  of  the  umbilicus  (somewhat  higher  when  recum- 
bent than  when  standing);  and  the  sigmoid  flexure,  extending  from  well 
down  in  the  left  side  of  the  pelvis,  up  out  of  the  pelvis,  and  then  down 
again  into  the  rectum. 

ClHintjt'x  in  Position  of  Colon. — In  cases  of  enteroptosis  the  shadow 
of  the  transverse  colon  may  fall  far  down  in  the  pelvis,  but  on  operation 
in  the  recumbent  position  this  may  he  found  to  have  been  somewhat 
exaggerated  in  the  picture1.  Cases  of  old  adhesions,  like  Fig.  712,  a 
patient  of  Dr.  Kemp's  who  had  been  operated  upon  for  appendicitis  and 
pericolitic  adhesions,  sometimes  show  the  hepatic  flexure  much  below 
its  normal  level  and  the  whole  ascending  colon  and  cecum  fallen  together, 
instead  of  extending  up  along  the  right  side  of  the  abdomen. 

\ortntil  J'IIWKJC  of  Food  Through  tin1  Colon. — There  is  a  to-and-fro 
peristalsis,  which  favors  the  absorption  of  the  nutrition  from  the  colonic 
contents  and  a  slow  general  progress  toward  the  rectum,  with  occa.-ional 
forward  mot  ion  of  a  mass  occupying  a  large  part  of  the  length  of  the  colon. 
Hol/knecht  first  observed  this,  and  found  that  it  takes  place  only  once 
in  about  eight  hours. 

Obstruction  of  the  colon  would  show  by  arrest  of  the  bismuth  meal  and 
also  of  the  rectal  injection.  A  case  of  the  author's,  also  a  patient  of 
Dr.  Kemp,  has  very  marked  constipation  following  operations  upon  the 
appendix  and  ovaries  and  uterus.  A  bismuth  injection  was  given,  but 
no  meal. 

The  radiograph  in  the  recumbent  position  showed  the  normal  out- 
line of  the  colon,  but  at  the  place  where  the  transverse  colon  crossed  the 
spine  there  was  a  clear  area  o  inches  in  length.  This  was  evidently  a 
portion  of  the  colon  through  which  the  liquid  injection  could  readily 
pass,  but  which  was  kept  flattened  out  instead  of  becoming  distended. 
The  picture  was  so  good  as  to  make  this  quite  positive1,  and  its  appear- 
ance suggested  pressure  upon  the  colon  where  it  crossed  the  prominent 
vertebra1.  This  sometimes  produces  a  similar  aspect  and  must  be 
guarded  against.  In  this  case  it  was  excluded  by  the  fact  that  the 
place  in  question  was  at  the  upper  part  of  the  abdomen  and  the  line 
of  demarcation  was  very  sharp.  Another  possibility  was  pressure  from 
a  tumor,  but  there  were  no  signs  Of  this  in  the  radiograph  or  upon  palpa- 


102S  MKD1CAL     KI.KCTmriTY     AND    KoNTr.KN     HAYS 

lion.  The  probability.  \  herefore.  \v:is  that  it  was  due  to  pressure  by  a 
band  of  adhesion-.  Fpon  operation  by  Dr.  Parker  Syins  there  was 
found  a  band  of  adhesions  :•>  inehes  broad  ;ind  encircling  two-thirds  of 

the  cirruint'erence  of  t  lie  gut . 

Chninji  N  in  tin  N.'':<  ami  Motiliti/  of  Different  I\iri*  of  UK  Colon. — 
Moii'acolon.  or  me^acecum.  .-how.  by  an  enormously  large  shadow,  and 
in  cases  where  the  lirst  injection  ot  a  couj)le  of  pint-  surest s  this  coii- 
dition.  a  much  larger  injection  will  reveal  the  extent  of  the  dilatation. 
In  a  recent  case  the  cecum  and  lower  part  of  the  ascending  colon  were 
very  laru'e.  while  the  caliber  of  the  descendinu  colon  was  very  small. 
No  coii-t  ipat  ion  wa-  present  a.-  a  result  of  thi-  condition. 

('«•/////  tnohili  ,  or  unnatural  mobility  of  the  cecum.  will  be  shown 
by  it-  change  of  position  on  pres-ure.  It  has  been  thought  to  have  a 
cau-ative  ettect  in  -ome  case>  ot  appendicitis. 

Chmnic  co/<xti /Hitioii  is  often  shown  to  be  due  to  malposition  or  pros- 
sure  or  contraction  at  >ome  part  of  the  colon,  and  sometimes  the 
condition  revealed  by  the  ./'-ray  is  one  requiring  operation.  It  may  be 
sh"\vn  to  be  due  to  simple  muscular  weakness  in  the  wall  of  the  colon 
evidenced  by  lonsj;  retention  in  the  colon,  or  it  may  be  shown  to  bo  duo 
to  adhesions  of  the  rectum  or  sigmoid  producing  mechanical  obstruction. 
If  the  .r-ray  shows  the  bi-muth  meal  long  retained  in  the  rectum  this 
would  indicate  lessened  sensibility  and  reflex  action  there,  or  spasmodic 
cont  r.ict  ion  of  t  he  sphincter  ani. 

The  rectum  and  -igmoid  flexure  are  best  seen  after  an  injection 
which  I-  m.  71  I1  does  not  extend  beyond  these  parts. 

The  Skiagraphic  Enema.—  For  a  rectal  injection  a  decoction  of  potato 
Hour.  1  ounce  to  2  pints  of  water,  i>  prepared  by  mixing  the  potato 
flour  at  fir-t  with  a  small  amount  of  cold  water  and  then  pouring  it 
into  boiling  water.  Three  or  4  ounce-  of  barium  sulphate  are  thor- 
oughly mixed  with  this  liquid  ( von  ( lourevitsch).  The  decoction  must 
be  perfectly  liquid  or  it  will  no!  flow  properly  through  the  tube.  This 
pui.-ito  mixture  iiives  excellent  picture-,  and  the  author  prefers  it  to  the 
following  formula,  which  has  only  the  advantage  of  requiring  no  cooking 
barium  sulphate,  '.'•>  ounce-;  bolus  alba  purified  powdered  kaolin). 
',  pound,  and  water  up  to  '2  pints.  Many  of  the  author's  radiographs 
have  been  made  with  thi-  mixture  and  never  with  any  bad  effect,  but 
i'  i-  ciincei\  able  that  some  of  it  minht  be  retained  and  become1  dry  and 
hard. 

Foreign  Bodies  in  the  Stomach  and  Intestines.—  These1  are  readily 
located  if  metallic,  of  as  larize  sixe  as  a  coin,  and  if  the  person  is  not  too 
Ian:'1.  A  needle  might  e-cape  detection. 

The  .r-ray  ha-  been  used  to  locate  stolen  property  swallowed  by 
criminal-.  '1  hi-  i-  -aid  to  have  been  done  at  the  diamond  mines  and 
ai-u  in  the  mint  in  Japan,  and  a  stolen  rmi:  ha-  been  located  in  this 
\\ay  in  the  pri-on  at  I  )a\  enport .  Iowa. 

Radiographic    Studies    of    the    Passage    of    Different    Food-stuffs 

from  the  Stomach  and  Through  the    Small    Intestine.     Observations 

been  made  by  \\  .  I',  ('aniioii'   upon  a  cat,  to  which  '2-~i  cc.  of  fats, 

•  '       irbohvdrate-,  <>r  of  albumin    wa-   given,  mixed   with  bismuth  sub- 

/•<;/.-•   were    ,-een    to    remain    in    the    -tomach    for   a    long   time, 

uradiial  v  pa  —  nm    into    the   small    intestine   as   the  previous  portions  of 

I '-orbed   or   passed   into    the   la  me   intestine.      There  was   no 

accumulation  nf  fat  in  the  small  intestine.     A/hunii/ioitlx  were  seen  not 

:  Am.  .lour,  of  I'hy.-inlotrv,  U,  IJss,  I'.tOl. 


TIIK    .r-KAY 

to  leave  the  stomach  during  the  first  half  hour,  except  white  of  egg, 
which  almost  immediately  passes  into  the  small  intestine.  The  maxi- 
mum amount  of  albuminoid*  is  found  in  the  small  intestine  at  the  end 
of  two  hours.  ( '(ir/>olii///i-n/i  x  pass  direct  ly  into  t  he  duodenum.  A  mixture 
of  fnts.  iillm /in  nnnls,  and  I'ltrhufn/flffitcn  has  an  intermediate  t  hue  fit  re- 
tention in  the  stomach.  The  presence  of  the  fats  slows  the  progress  of 
the  other  two.  DoiihliHi/  the  amount  when  carbohvdrates  are  niven 
alone  increases  the  rapidity  ot  passage,  hut  doubling  the  amount  of  an 
albuminoid  meal  retards  it.  'I'he  moment  at  which  the  different  food- 
stuffs administered  singly  appear  in  the  large  intestine  is  about  four 
hours  for  carbohydrates,  live  hours  for  fats,  and  six  hour.-  for  albu- 
minoids. 

Radiographic  Characteristics  of  the  Stomach  in  the  Infant.— 
Leven  and  Barrel1  find  that  the  infant  stomach  lies  in  a  hori/ontal 
position,  with  a  portion  ot  its  greater  curvature  lowermost.  It  seems 
always  in  a  condition  similar  to  that  known  as  dilatation,  not  adapting 
itself  at  all  times  to  the  volume  of  its  contents  as  in  the  adult.  After 
the  iugestion  of  sO  to  17")  cc.  of  milk  the  infant  stomach  empties  itself 
in  from  one  and  three-quarters  to  two  hours. 

Other  radioscopic  studies  of  the  infant  stomach*  show  that  it  con- 
tract- throughout  ITS  entire  extent,  not  merely  around  the  pylorus, 
as  in  the  adult.  This  contraction  is  a  reflex  from  the  gastric  muco-a. 
and  if  the  latter  is  hypersensitive,  vomiting  occurs.  Obstinate  vomit- 
ing of  infancy  is  not  a  condition  of  stenosis  or  spasm  at  the  pylorus. 
Km  one  of  hypersensil  iveness,  and  this  may  be  promptly  relieved  by  the 
administration  of  sodium  citrate. 

Radiography  Applied  to  the  Desmoid  Test  of  Stomach  Func- 
tion.— The  digestion  of  connective  tissue  may  be  ,-tudied  by  having  the 
patient  swallow"  a  capsule  made  ,,f  thin  pi  Id-beater's  skin  and  contain- 
ing -'2  nr.  of  powdered  black  iron  oxid.  This  is  to  be  taken  at  the  end 
of  an  '  n'i  linary  meal. 

A  radiograph  made  seven  hours  later  will  show  whether  the  ^old- 
beater's  skin  has  been  digested.  This,  according  to  some  observers, 
i-  the  average  time  required;  if  not,  the  capsule  of  iron  still  shows  a 
i  li.-t  inct  dark  spot. 

(J.  \Y.  Schwartz3  found  that  connective  tissue  was  completely  di- 
gested in  two  hours  in  a  case  of  very  marked  hyperacidity  of  the  gastric 

jUire. 

I>.  Horwit/4  has  emploved  Schwartz's  method  in  1  1  cases.  He  gives 
a  little  bag  of  bismuth  after  a  regular  test  breakfast,  and  has  the 
patient  lie  on  his  left  side  to  retain  the  capsule  in  his  stomach  as  lonn 
as  possible,  and  the  patient  should  take  nothing  but  lea  and  water 
during  the  entire  day.  A  little  piece  of  thin  rubber  tissue  tied  around 
the  bismuth  with  00  catgut  may  be  used  instead  of  the  ban  of  ^old- 
beater'-  skin.  The  catnut  is  digested  in  the  same  length  ot  time  as 
nold-beater's  skin.  lie  says  that  if  radioscopy  show.-  the  bi-muth 
;i-  ;i  -mall  opaque  >pnt  in  the  stomach  or  intestines  more  than  three 
hour-  after  swallowing  it,  tin-  indicates  a  lack  oi  acid  in  the  gastric 
secretion.  When  the  connective  tissue  of  the  ban  i-  < line.- ted  the 


1030  MKDICAL    F.I.K(   1HK  II  V    AM)    RONTGEN    RAYS 

bismuth  escapes  and  is  seen  as  a  larger  and  valuer  area  of  cloudiness, 
and  if  this  takes  place  in  an  hour  and  a  half  or  less,  extreme  hyper- 
acidity is  present.  Freeing  of  the  bismuth  in  two  hours  indicates  moder- 
ate hyperacidity:  in  two  and  a  half  hours,  normal  stomach  digestion; 
in  three  and  a  half  hours,  slight  hypo-acidity;  in  four  to  four  and  a  half 
hours,  extreme  hypo-acidity;  and  in  five  hours,  anacidily.  The.  last- 
named  condition  was  always  found  in  cases  of  cancer  examined  in  this 
way. 

Thi-  is  a  modification  of  Sahli's  desmoid  test,  based  upon  the  fact 
that  the  raw  connective  tissue  of  the  bag  is  not  digested  by  the  pan- 
creatic or  intestinal  secretions,  but  only  by  the  gastric  juice,  and  only 
when  the  latter  contains  pepsin  and  free  hydrochloric  acid. 

Schwartx's  radiolo^ic  observations  show  that  no  ingesta  of  any 
kind  are  ever  retained  for  more  than  ten  hours  in  a  stomach  of  ap- 
proximatelv  normal  si/.e  and  without  stenosis. 

Hot'fnian's  conclusions  from  the  radiographic  examination  of  100 
patient-  with  diseases  of  ilie  stomach  are  that  the  .r-ray  is  only  oc- 
ca-iotiallv  of  assistance  in  diagnosis. 

If  the  stomach  is  dilated  bv  gas  and  a  bougie  is  introduced,  the 
latter  should  norinallv  follow  a  certain  definite  curve,  but  in  gastrop- 
tosis  the  bougie  is  seen  in  the  radiograph  to  pass  almost  straight  down 
to  an  unnaturally  low  level.1 

An  hour-glass  stomach  was  diagnosed  by  Holzknecht  and  Brauner.2 
The  radiograph  was  made  with  the  patient  lying  upon  his  back  upon 
the  plate  with  the  tube  over  the  abdomen.  He  had  swallowed  a  sort  of 
paste  made  of  rice  and  milk  and  powdered  bismuth  subnitrate.  Two 
dark  shadows  could  be  seen  separated  by  a  clear  area  representing  the 
place  of  constriction. 

Fig.  7b>  by  the  author  shows  an  hour-glass  stomach  resulting  from 
old  adhesions.  The  patient  was  referred  by  Dr.  Kemp. 

An  example  of  the  value  of  the  .r-ray  in  the  diagnosis  of  intestinal 
diseases  may  be  mentioned  -a  case  described  by  \\  iesner.'1  An  opera- 
tion for  appendicitis  was  followed  by  attacks  of  acute  colitis  occurring 
every  two  or  three  weeks.  Radiologic  examination  revealed  the  fact 
that  the  ceciim  and  a  part  of  the  descending  colon  were  bound  down 
by  adhe-ions.  and  that  a  small  blind  pouch  had  been  formed  in  this  part 
of  the  inte>tines.  This  was  relieved  by  an  operation  and  another  radio- 
graph three  months  later  showed  the  colon  in  normal  position.  The 
colon  i-  to  be  injected  with  a  metallic  mixture  before  making  such  a 
radiograph. 

Technic  for  Radiologic  Examinations  of  Stomach  and  Intestines. 

Hul-t1   ha-  elaborated   a    technic   for    the    radiologic    examination   of 

the  stomach   and   intestines  which  is  an    abridgment    of   Holzknecht.V 

and  i-  ba-ed   aUo   upon    Hieder's"   work.      The    patient,  whose  stomach 

known  to  be  empty,  -tands  in  front  of  the  .r-ray  tube,  which  is  en- 
an  opaque  <hield  with  a  diaphragm  provided  with  a  small 
a  direct  line  with  the  focus  of  the  tube.  The 


.  AiiL'u-t  .'!,  MHI.'I. 
in'  V  I'.Ht."),  p.  rrJI 
Man-li  :•;.  I  (.n  is. 

[it'_"-tio|(iLrV.    .Inn   ,    1  '.KI7 

f    K:r!ioli>u  .   hi-,- .,  ;,,„!  'riicrap 

I      Uui'iit  LTi'H.,     Vi  il      \  ill,    \'i.    '.',. 


THK    X-RAY 


KKU 


the  normal  ray,  or  a  regular  orthodiagraph  may  he  used.  The  patient 
swallows  a  Seidlitx  powder  in  two  parts,  the  soda  first  and  then  the 
acid,  each  dissolved  in  half  a  glass  of  water.  The  posit  ion  of  the  right 
and  left  domes  of  the  diaphragm  are  noted  hy  fluoroscopy,  penetration 
No.  ">  or  (1  Walter.  Now,  as  the  stomach  fills  with  gas  it  looks  trans- 
parent, like  the  lungs.  This  light  area  may  he  traced  through  a  series 
of  radiographs  and  is  called  the  M/i</<-nhl<is<-  ((ierman  equivalent  for 
stomach-bubble).  The  amount  of  upward  displacement  of  the  dia- 
phragm hv  this  gas  is  noted,  and  then  the  patient  is  given  a  bolus 


containing  •_>."">  gr.  of  bismuth  subnitrate.  It'  tlie  patient  is  turned 
l.">  decrees  to  either  side  the  opaque  mass  may  be  watched  as  it  passes 
down'  through  the  esophagus.  A  swallow  of  water  may  he  required 
to  assist  this.  Looking  at  the  patient  from  directly  in  front  tluO/m/</?- 
hlttm  is  seen  to  become  narrower  and  to  lengthen  downward.  1  he 
bismuth  does  no1  at  once  pass  to  the  lowest  part  of  the  stomach,  hut 
it  may  require  pressure  upon  the  abdomen  to  cause  it  to  do  so.  A 
mark 'indicating  the  lowest  part  of  the  stomach  is  then  placed  upon  the 
skin.  The  patient  then  swallows  M)  gr.  of  bismuth  suhmtrate  m 


1 1  i:V2 


MEDICAL    ELECTRICITY    AND    ROXTGEX    HAYS 


'.)  ounces  of  water,  and  this  is  watched  with  the  fluoroscope  as  it  passes 
down  into  the  lowest  part  of  the  stomach.  The  patient  then  lies  down 
while  he  swallows  an  ounce  of  bismuth  subnitrate  in  a  pint  of  milk. 
The  opaque  substance  now  tills  the  entire  stomach,  and  lluoroscopy  or 
radiography  is  practised  from  different  directions:  for  instance,  a  radio- 
graph is  made  with  the  plate  under  the  abdomen  and  the  tube  over  the 
back,  in  a  direct  line  with  the  umbilicus. 

Neither  a  dorsovent  ral  or  ventrodorsal   radiograph,   made1  with   the 
patient  lyiiiii  upon  the  plate  face  up  or  face  down,  shows  whether  there 


i-  <_ra-tropiosis  or  not.      If  it  is  present,  these  two  positions  tend  to  cor- 
rect jt. 

\Vh.-ii  they  do  -how  i<  the  si/e  and  shape  of  the  stomach,  whether 
there  is  any  constriction,  and  sometime-;  whether  there  is  a  tumor  of  the 
;tniii;irh  wall.  Thi-  wa-  shown  in  one  of  I  lol/k necht '-  cases  by  a  por- 
tion free  from  t  he  bi-mut  h  opacit y,  t  he  tumor  project  inji  into  the  cavity 

-toinaeh  and  di-plac'm<:  ju-t   so  much  of  the  bismuth. 
1  ine  of  Hul-t'-  cases  of  ira-^t  roptosis  showed  in  the  hori/ontal  dorso- 
ihai   the  caudal  pole  of  the  -lomach  was  at   the  level 
lumbar   vertebra,    while    in    the   erect    position    the   caudal 
P1  ile  '»\  :         hind  t  he  -ymphysis  pul  >is. 

\    :  M  ph    made    -i\    hours   after    the    inire-tion    of    the    bismuth 


will  show  whether  il  has  passed  out  of  the  stomach,  and  will  thus 
test  the  motor  efficiency  of  the  organ. 

Later  radiographs  will  trace  the  bismuth  through  the  intestines. 

Use  of  the  Duodenal  Tube  in  Radiography.  An  elongated  -tomach- 
tube.  with  a  perforated  metal  ball  at  the  end,  is  passed  into  the  ,-tomach 
after  swallowing  a  glass  of  milk  and  water.  'The  patient  lie-  on  hi.-  right 
side  and  after  a  time  the  tube  pa.--es  into  the  duodenum.  Then  a  rub- 
ber ball  surrounding:  the  metal  end  of  the  stomach-tube  may  be  inflated 
and  will  arrest  the  passage  of  a  -mall  bismuth  meal  through  the  duode- 
num in  such  a  manner  as  to  secure  an  accurate  radiograph  of  t  his  port  ion 
of  the  intestine.  The  duodenal  ball  is  deflated  and  the  apparatus  is 
drawn  out  through  the  mouth,  dross  and  Kinhorn  and  Cole  and 
Skinner  were1  the  pioneers  in  this  method. 

Intensifying  Screens  in  Gastro-intestinal  Radiography.  There 
is  no  need  for  great  detail  in  these  picture-,  and  there  is  every  rea.-on 


n 


.-  Fin.  71 


for  desiring  to  make  short  exposure:-.  A  transformer  current  ot  '.»() 
kilovolts  and  about  .")()  ma.  will  make  these  with  an  exposure  ot  le-s 
than  one-quarter  second  if  a  good  intensifying  screen  i-  used. 

The  Author  is  Opposed  to  Cinematography  of  the  Stomach.-  Such 
a  rapid  -cries  of  pictures  can  only  be  made  upon  a  iilm.  and  film-  require 
a  longer  exposure  than  the  fastest  plate-.  Modern  .r-ray  apparatu-  are 
so  powerful  that  with  the  most  rapid  plate  and  the  best  intensifying 
-creen  a  u'ood  picture  may  be  made  with  an  exposure  ot  one-twentieth 
to  oii"-tifth  second,  or  with  a  film  and  an  intensifying  -creen  one-tilth  to 
one  second.  Hut  to  do  thi-  the  same  amount  of  .r-radiation  traverses 
the  body  as  if  a  12-inch  induction-coil  were  u-ed  with  the  same 

nd    an    exposure    ot 


1034 


MKDICAL    KLKCTKICITY    AND    H()NT(iF.N    RAYS 


tir  forty  exposures  of  one-fifth  second  each  with  the  strongest  current 
radiance  does  not  seem  as  risky  as  twenty  or  forty  exposures  with  the 
radiance  formerly  employed.  Imt  such  is  the  case.  All  the  necessary 
information  may  he  safely  gained  with  a  comparatively  small  number 
of  the  most  sensitive  plates  reinforced  by  the  best  intensifying  screen. 
( '<>!(  'N  (irnuKjcnicnt  for  nultocincHiutoyraphy  comprises  a  lead  box  like 
a  camera,  in  which  the  film  extends  from  one  roller  to  the  other  under  an 
intensifying  screen,  against  which  the  film  is  pressed  at  the  moment  that 
the  current  is  turned  on.  The  current  is  broken  automatically  after  a 
certain  fraction  of  a  second,  the  pressure  upon  the  film  against  the  inten- 
sifying sen-en  is  released,  and  another  portion  of  the  film  unwound.  The 


I  i_r.    Tl'i       Kadioirranh   of  stomach.      Deformity  of  duodenal   cap  indicative  of  ad- 


niall    diaphragm    was    used,    tin1    stomach    having    been 


.•:•..    ,       iti-d    liv   pn-\  ions   radiographs 


picture-,  of  ciiurse,  ;ire  the  full  si/e  of  the  -tomach,  and  reduced  copies 
ai'e  made  upon  ;i  -trip  of  cinematograph  film. 

It  is  nut  practicable  to  make  cinematograph  pictures  directly  with 
a  camera  pointed  toward  the  fluoroscopic  screen  as  if  that  wen-  a  mov- 
ing object.  The  expo-ure  would  have  to  be  so  ion"1  as  to  give  a  blurred 
iinai!'-  i>t  any  moving  object . 

The  author  is  strongly  opposed  to  the  use  of  the  fluoroscope  either 
fur  examination  or  tor  the  purpose  of  determining  the  most  favorable 
p'i-i'i<i!i  Hi-  time  fur1  makinii"  the  radiographic  exposure.  It  is  safest 
t  •  the  ijj  •  itor  tii  have  him  -land  behind  a  screen  of  -heet-lead  or  of 
.  preferably,  nut  in  a  direct  line  with  the  .r-ray,  but  to  one 
side,  where  he  can  view  the  fluoroscopic  imaLTe  in  ;i  mirror.  The  fluoro- 
scopic -creeii  may  }<>•  vertical  with  the  patient  -tandinu  before  it,  or  it 


THE    X-HAY  lOH") 

may  ho  horizontal  under  the  table  upon  which  the  patient  lies.  Safe 
as  it  may  ho  made  iur  the  operator,  an  element  of  danger  remains  for 
the  patient,  in  the  fact  that  while  the  .r-radiance  may  he  reduced  to  a 
weaker  strength  than  used  in  radiography,  any  fluoroscopv  takes  a  tre- 
mendously longer  time,  and  could  only  he  made  relatively  safe  hy  deter- 
mining beforehand  the  danger  limit  and  using  a  time-switch  to  turn  off 
the  current  long  before  that  had  been  reached.  Not  alone  the  po.-sibilitv 
of  dermatitis,  but  of  disturbance  of  blood,  metabolism,  and  excretion 
must  be  taken  into  account  in  determining  the  safe  time  of  exposure. 
Accidents  with  the  fluoroscope  wore  frequent  in  the  early  days  when  used 
in  the  search  for  foreign  bodies  in  the  hand  or  for  the  examination  of  the 
knee  and  other  joints.  The  extension  of  its  use  to  the  stomach,  where  a 
much  stronger  radiation  is  required,  is  additionally  dangerous. 

THE   AUTHOR'S   TECHNIC   FOR   GASTRO-INTESTINAL   RADIOGRAPHY 

Preparation.- -For  forty-eight  hours  before  no  .-olid  food  or  any- 
thing containing  milk;  plenty  of  nourishment  can  be  taken  in  the  form  of 
clear  soups  and  broths,  or  clear  jellies,  coffee  or  tea  wit  h  sugar,  but  with- 
out milk  or  cream;  these  can  be  taken  every  t  h  roe  hours.  A  laxat  ive  t  wo 
nights  before  and  a  laxative  the  night  before  the  examination.  A 
prescription  is  given  for  tinct.  belladonna,  dose  10  drops,  to  be  taken 
three  times  a  day  before  meals;  and  the  last  do.-o  to  he  taken  the 
morning  of  the  examination  first  thing  when  getting  up:  then  fifteen  min- 
utes later  to  bo  followed  by-?,  teaspoonful  sodium  bicarbonate  in  water. 

Composition  of  the  Barium  Meal.—  This  consists  of  5  ounces  of 
barium  sulphate  thoroughly  mixed  with  fermillac  (two  .'-pint  bottles  : 
this  amount  fills  two  cups. 

Postures  for  Gastro-intestinal  Radiography. —  1.  Standing  with  the 
tube  behind,  anticathode  2o  inches  from  the  plate,  and  the  plate  at  an 
adjustable  height  in  front;  umbilicus  usually  at  middle  of  plate.  We 
must  not  allow  the  patient  to  assume  the  "straight-front"  posture,  as 
in  Fig.  717,  with  the  hips  so  prominent  behind  as  to  make  12  or  l-"i 
inches  of  flesh  to  be  penetrated  by  the  .r-ray  at  right  angles  to  the  plate. 
This  position  makes  it  impossible  to  get  a  good  picture  of  the  lower 
half  of  the  abdomen  in  a  stout  person  and  even  in  a  shapely  person.  as 
in  Fig.  71S  it  is  easy  to  see  how  much  more  uniform  the  ettect  on  dif- 
ferent parts  of  the  plate  will  be  with  the  patient  standing  with  the  puhes 
pressed  against  the  plate  and  the  hips  down.  This  first  position  is 
seldom  used  by  the  author,  because  it  is  less  convenient  and  less  certain 
to  yield  a  good  picture  in  any  but  a  slender  person  and  one  who  can  be 
depended  upon  to  stand  absolutely  still.  It  i-  used  occasionally  for 
the  first  picture  after  taking  the  meal,  to  show  the  very  lowest  level  to 
which  the  stomach  extends  in  a  case  of  severe  gastroptosis,  and  to  show 
the  exact  level  of  the  liquid  content-  of  the  -toinach  and  the  clear 
laver  above  the  opaque  meal.  The  author's  graduated  filter  tor 
equali/ing  the  exposure  (page  1011  will  frequently  be  required  tor  a 
i  1  x  17  inch  plate  in  this  posture. 

'_'.  Standing  in  an  inclined  position  with  the  abdomen  resting 
au'ainst  the  plate  and  the  feet  upon  an  adju-table  rest.  The  hips  as- 
sume a  desirable  position  naturally  V\^.  721  .  There  i-  a  mark  upon 
the  tube-stand  indicating  the  height  for  the  tube  and  the  aniilc  at  which 
it  should  be  inclined.  These  adjustments  are  made  fir-t .  1  he  patient 

most 


1030 


MKDUAL    ELECTRICITY    AND    KONTCKN    KAYS 


oases.  The  tube  is  placed  in  the  median  line  behind,  at  such  a  place 
that  the  anticathode  is  '23  inches  from  the  middle  of  the  plate.  This 
picture  -hows  the  level  to  which  the  stomach  extends  and  the  shape 


and    whether    the    duodenal    ca       fill-. 


turf   i-    made    in   this   po-ition   about    fiftee 


the  plate  under  the  abdomen  and  the  tube  over.  ; 


from   middle   <>f   the   plate,  which    i 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 
I 


i^.  721. — Semi-erect  posture  for  gastro-intestinal  radiography 


•••I  •••••••^•••MBI 

\  ;'!.'T'-    >ii  •  i'1'     n  :K]V   to  rceeive  the  pl:itc  in   its  eussette   fur  Castro-intestinal 
ruli'  'irr;i|  ili.v,   M'lni-erect . 


THE    X-HAY 


5. — Author's    device    for    gastro-intostimd    radiograph  v,  semi-orort.     AdjuM 


foot-rest.     Frame  holds  plate  at  proper  height. 


rip.  724.— -Author  s  frame  for  holding  plate  in  an  inclined    [lositinn  fur  gastro-intestinftl 


vals,  beinnninti'  three-quarters  of  ;m  hour  after  finishinji  the  1'ariuin  meal 
and  with  everv  effort  to  secure  dear  definition  ot  the  stomach  and 
duodenum  as  free  as  possible  from  respiratory  or  peri-taltir  movements, 
('are  must  be  taken  to  prevent  compression  ot  the  pars  pylorica  between 
the  abdominal  wall  and  prominent  lumbar  vertebra1.  As  a  routine 
mea-ure  have  a  cushion  about  '2  indies  thick  under  the  pelvis  and 
another  under  the  chest.  The  abdomen  should  re.-t  liuhtlv  on  the 


MKim  AI.  KI.KI  TKICITY  AND  KONTCKN   KAYS 


ioKrapm    "t    the   mte-ime:   proi 


\~>  degrees  lower  than  the  pelvis. 


RnuiOL'r.'ipliy  of  tlii'   ;ippenilix,  prone,  with  :i  Pornprcssioi 


L'  under  the  ri^ht 


1041 


plate  without  marked  compression.  The  hack  -hould  he  .-Iraiiihl 
( Fiii'.  7'2  1  ).  The  chest  and  face  should  he  right  <lo\vn  upon  thecu.-hion. 
the  patient  not  resting  upon  her  elhows.  The  author  ha-  adopted  the 
plan  ot  making  a  few  of  the-e  picture-  upon  11  \  17  plate-  which  are 
sure  to  include  all  parts  of  the  stomach  and  duodenum.  Thi-  i-  pref- 
erahle  to  making  a  Huoroseopic  examination  oi-  a  preliminary  radio- 
lira  ph  to  see  just  where  the  -tomach  is  and  then  making  -mailer  plate- 
of  just  tlie  right  part.  The  lower  edire  of  the  stomach  i-  s  inche- 
lower  in  some  patients  than  in  others.  After  the  11  x  17  plate-  of  thi- 


posture  are  made  the  portion  of  intere.-t  may  he  only  .s  x  10.  And 
thi-  i-  the  part  from  which  the  print  i-  made,  which  is  accordingly  on  a 
larger  -cale  than  the  prints  of  other  postures  which  show  the  whole 
11x17  plate  on  a  reduced  -cale.  These  pictures  are  to  show  the  dif- 
ferent -tau'es  of  gastric  peristal-is,  and  filling-defects  or  deformities 
of  the  stomach  or  duodenum;  and  really  u'ive  a  direct  view  of  ulcers, 
neoplasms,  and  deformity  from  adhesions. 

In  occasional  eases  where  the  stomach  H  empty  at   the  (Mid  of   -i\ 
hours,  hut    the  meal   ha-  not    pa--ed   heyond   the  cecum.  t!ie  picture-  in 
this  po-ture  had  hetter  he  repeated  every  hour  from  one   to  five    hour- 
t  it  i 


1042 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


after  the  meal  to  see  just   when  the  stomach  does  entirely  empty  and 
whether  the  delay  is  in  the  stomach  or  the  small  intestine. 

4.  Six  hours  after  the  meal  a  picture  is  made  of  the  region  of  the 
appendix.  The  plate  is  on  the  table,  then  a  rubber  pneumatic  bag, 
then  the  patient  prone.  The  rubber  bag  is  to  be  inflated,  but  the  patient 
is  told  to  relax  the  abdominal  muscles  and  rest  all  her  weight  on  the 
bag.  The  idea  is  not  to  raise  the  entire  patient  from  the  plate,  but 
to  compress  the  right  iliac  region,  pressing  away  the  cecum  and  giving 


I'L'.  7_'v  —  I'to-i-  of  hepatic  flexure.    The  other  radiograph  -how-  that  the  apparent  angu- 

lation   at    X   in   this  one  i>   perfectly  free  iii  ToilM'v's   position. 

drill1   view   of  the  ;ip].rndix.      The  appendix   plate   is  S  x    10  indies. 
All  the  dt  hers  are   I  I  x   17  indies. 

.">.  Six  hour-  after  the  meal  a  picture  is  made  in  the  same  posture  as 
N<>.  L'.  to  -how  whether  the  >tomadi  is  empty,  what  parts  of  the  intes- 
tine  are  occupied  by  the  meal,  and  whether  there  are  malpositions  or 
deformit  ic-  ( if  any  part  s. 

hmir<  after  the  meal  and  immediately  after  an  enema  con- 
;i>tiim  iii  ID  ounce-  of  barium  .-ulphate  and  1 !  pints  of  warm  water 
a  picture  i-  maile  iii  the  -ame  posture  as  Xo.  2.  Thi<  <hows  especially 


THE    X-RAY 


1043 


Fit;.  729. — Enteroptosis  with  adhesions.      Intestine  does  not   gravitate  toward  thorax  in 


TOUSPV'S  position.     A  belt  would  afford  no  relief. 


Fiir.    7.SO.      Gastnmtnsi.-;    and    Miirht    ira-trn1    retention.      Marked    enterni.ti  i>i~.      Ap- 


11)41 


)ermeability  and  dilatability  and  position  of  all  part-  of  the  larjio 
t  inc. 

.   Six    hours   after   the   meal    and    immediately   after   the   enema   a 

•  irraph   is  made  in   the  author's  position   (Fiji.   72.1'.      The  patient 

iroiic  upon  the  plate  inclined  so  that  the  pelvis  is  45  decrees  higher 

the    chest.     The   elbows   and    shoulders    rest    on    cushions    raised 

the  floor  and  the  limbs  extend   alonji  the   top  of  the  table.     This 

ire    -hows    especially    whether    different    part>    of    the    transverse 

i  are  free  to  jiravitate  toward  the  thorax.      Number  (1.  for  instance, 

have  shown  ptosis  of  the  transverse  colon  way  down  into  the  pel- 

ind  Xo.  7  will  show    whether  it   is   bound  there  bv  adhesions  and 


Hadiotrriiphy    of    the    -toniach    and    duodenum,    prone,  with    thoraeir    and 


i-    to   prevent    coiniin---ion   of   the   stomach   anain.-t    t  he  hodies  of  the  verte- 


c'liild  only  be  benefited  by  an  operation.      If  it  jiravitates  freely  toward 
thorax   in   the  author'-  position  a   belt   and   pad   miu'ht   relieve  the 
-•.in'  >'  •  ifn-. 

The  Author's  Graduated  Screen  for  Equalizing  x-Ray  Exposures. 

an  invention  of  the  author's,  consisting  of  a  -licet  of  aluminum 

inch   thick  ;,||,1  |i;i\-inii  one  or  both  edu-c-  beveled  for  about    ?, 

to  coini-  'o  a  thin  eiltie.      It   i-  fastened  to  the  tube-<land  in 

•-  ii'*'inii'  to  the  thinnest  poll  ion  of  the  patient  must 

the  thicke-t  purl  of  1  he  aluminum  and  be  corre.-pondinu'ly 

while    unobstructe*!    rays    pas.-    to    the    thickest 

lepirted.      The  bevel  corre-pon<l-  to  the  transitional 

'   aiid  i  he  thin  edire  pre\'ents  MIIV  di\'idiim'  line  in  the 


10  If, 


picture  between  the  pai'1  ;iftecle<l  bv  llie  aluminum  -creen  and  the  part 
which  is  not.  Thi.-  enable-  one  to  secure  a  unifonn  exposure  of  i  he 
abdomen  and  pelvis  of  a  patient  with  a  27-inch  wai-1  and  lo-iiich  hip.-, 
where  ordinarily  one  part  would  lie  either  ^'reatlv  over-  or  underex- 
posed ii  tin1  other  were  riuht.  For  a  Castro-intestinal  case  \\ith  -imilar 
measurements  the  author  uses  a  screen  which  cover-  one-half  of  the 
opening  in  the  tube-shield;  while  for  a  person  with  a  similar  figure  re- 
quiring a  kidney  picture  he  uses  a  narrow  strip  extending  aero--  the 


middle  of  the  opening1.  In  the  latter  ra-e  overexposure  of  t!ie  lumbar 
k-ertebne  i-  avoided,  while  securing  full  exposure  <>f  the  peh'i-  and  the 
lower  <  1< ir-al  reu:i< m. 

\<i><  I.  The  umbilicus  is  usually  about  at  the  level  of  the  crest 
of  the  ilium  and  i-  to  be  at  the  middle  of  the  plate.  Hut  in  a  tall  per- 
son  the  umbiliru-:  i-  u-uallv  far  above  the  cre-t  of  the  ilium  and  the 
stomach  is  apt  to  be  at  a  very  high  level.  In  -udi  a  per-on  the  umbilicii- 
i-  a  much  better  li'uide  for  the  proper  position  of  the  plate  than  the  crest 


1046 


MEDICAL    ELECTRICITY    AND    ROXTGEN    RAYS 


of  the  ilium,  and  very  often  the  middle  of  the  plate  will  have  to  be  an 
inch  or  two  above  the  umbilicus  to  include  the  entire  stomach  showing 
upon  a  14  x  17  inch  plate.  In  a  person,  on  the  other  hand,  whose  um- 
bilicus is  below  the  crest  of  the  ilium  the  latter  should  be  at  the  middle 
of  the  plate. 

\<>fr  2.  Each  intestinal  picture  ought,  if  possible,  to  show  the  en- 
tin1  intestinal  tract.  The  standing  plates  ought  to  be  low  enough 
to  include  the  anus.  This  will  ordinarily  be  the  case  with  the  um- 
bilicus at  the  middle  of  the  plate,  but  with  a  tall  or,  rather,  a  long  bodied 
person  we  must  be  sure  that  the  perineum  is  above  the  lower  edge  of 
the  plate.  In  this  long  bodied  person  the  standing  plates  may  very 
well  not  show  the  uppermost  parts  of  the  intestine,  such  as  the  splenic 
flexure,  and  we  must  make  sure  of  including  this  in  the  final  picture,  in 
Tousey's  position,  though  it  be  at  the  expense  of  not  including  the 
lower  part  of  the  rectum. 

\d(i  o.  (iaU-stotic  Pictures. — The  gastro-intestinal  pictures  are 
precrded  by  one  before  the  barium  meal  to  determine  the  presence  or 


•c  oi  Lrall— Atones  or  other  calculi.     The  patient  lies  prone  upon  the 

plate  without   any  precautions  to  prevent   compre-sion  of  the  abdomen. 

Hi'1  uml>ilicu-  is  at  the  middle  of  the  plate  and  the  anticathode  directly 

;ibove  that  at  a  distance  of  '2'->  inche-.      The  -park  equivalent  should  be 

•-  \vit  hoiit  or  5  inches  wit  h  2  t  hickne<-e-  of  tin  to  arrest  secondarv 

I:LI'  in  the  tissues.      The  author'-  ura dilated  filter  open  above 

lull   reducing  the  inten.-ity  of  radiation  at  the  waist,  should 

For  a  lady  with  a  -mall   waist   and   larue   hip-  and   chest.      The 

In-low  and  with  aluminum  above  is  used  for  a  woman  with 

J-nia  and   wai-l    and   lariie  hip-.      No  liner  i-  u-ed  for  men  or  for 

larire   waists.      In    Kiii.  ~'.\'.\  gall-stones   -howed   even   after 

the  m 

Flie   expo-tin-   and   development    should    be   -uch    that    everv   detail 


THE    X-RAY  1047 

present  will  show  when  the  plate  is  held  up  before  daylight  at  the  win- 
dow. No  part  is  to  be  too  dense  for  that,  and  no  part  is  to  be  so  thin 
as  to  require  special  tnmsillumination  to  show  details.  The  plate 
which  a  professional  photographer  would  select  to  make  a  print  from 
is  best.  If  it  shows  clearly,  the  spine  from  in  front  and  the  lowest. 
ribs,  it  will  be  very  apt  to  show  a  "'all-stone  if  present.  The  fact  that 
the  picture  does  not  show  a  gall-stone  does  not  prove  its  absence;  but 
the  author  has  come  to  believe  that  the  above  technic  will  enable  one 
to  say  that  it  is  unlikely  that  a  "'all-stone  is  there. 

\ot<-  4-  r'"n(>  duration  of  the  exposure  should  theoretically  be  one- 
fifth  second  or  less,  so  that  the  peristalsis  could  not  possibly  show.  With 
such  an  exposure  the  stomach  would  be  just  as  sure  to  be  motionles.- 
in  the  picture  as  the  minute-hand  of  a  clock  in  such  a  snapshot.  A 
gastric  exposure  lasting  several  seconds  may  show  movement  similar  to 
that  of  the  minute-hand  of  a  clock  in  an  exposure  of  a  minute  or  more. 
Hut  in  the  author's  experience  an  exposure  of  one  to  three  second-  for 
the  prone  pictures  of  the  stomach  gives  all  the  necessary  freedom  from 
motion  with  a  much  easier  technic  than  much  shorter  exposures.  The 
equivalent  spark  should  be  .">  inches  or  more  and  the  exposure  and  de- 
velopment should  be  such  that  the  plate  shows  excellently  when  held 
before  a  window;  the  spine  quite  transparent  but  with  good  detail  and 
the  stomach  very  transparent,  while  the  abdomen  at  either  side  is  very 
dense.  The  plate  should  make  an  excellent  print,  showing  the  stomach 
black  upon  a  generally  white  background  and  uive  a  good  print  of  the 
symphysis  and  ranii  of  the  pubes  and  of  the  hip-joint-.  A  stomach 
plate  whi.-h  requires  special  transillumination  should  not  sati.-fy  one. 
Some  latitude  in  the  matter  of  exposure  can  be  compensated  for  in 
development,  but  great  overexposure  with  accompanying  undcr- 
developmeilt  or  the  reverse  can  neves1  produce  the  best  results.  The 
best  way  is  to  have  a  certain  technic  and  vary  -imply  the  time  accord- 
ingly to  the  sex,  weight .  height .  and  waist  and  hip  measurement-.  <  )ne 
-hoiild  record  all  these  factors  in  regard  to  every  exposure,  as  well  as 
the  name  of  the  plate  and  intensifying  screen  and  the  nature  and  dura- 
tion of  development;  also  the  quality  of  the  re-ultiim  plate.  At  first 
it  may  be  better  to  vary  the  time  of  exposure  in  the  different  picture-  of 
the  same  patient  instead  of  haxardinu'  them  all  <>n  the  time  estimated  to 
be  riiiht.  Yerv  -non  one  has  a  record  from  which  one  can  find  an  expo— 
lire  which  has  .riven  a  perfect  result  fur  a  previous  patient  with  the 
same  weight  and  measurement  as  the  case  in  hand.  And  later  one  may 
compile  a  table  like  the  author'-  which  i-  merely  given  a-  guide  tor  u>e 
while  acquiring  one's 

Xoft    •'.      Author'- 
i-  found  on  pa  tie  S(,)S. 

\i>f<  (].  Sn/nal  for  Patient  to  //.</,/  //;>•  Hr<(itf>.-  In  gastro-intestinal 
radiography  it  i-  indispensable  thai  the  patient  >h<>uld  not  breathe 
dunnir  the  expo-ure.  The  author  ha-  a  doorbell  fastened  on  the  out- 
side of  his  .r-ray-proof  booth  which  i-  runii  by  turning  a  handle  inside 
the  booth.  The  patient  i-  told  that  at  fir-t  lie  will  hear  the  -oiind  of 
the  machinery,  and  that  when  the  bell  riim-  he  i-  to  hold  hi-  breath 
until  the  operator  iiives  a  second  -iiiiial.  when  he  can  breathe,  but  not 
k  the  apparatu-. 

ail  Print*  «/  <;<!.«<••,  -'//,,/ ',.,//  A',-,/;,,;/.-,//,  I,*.-  The  Au- 
plate as  a   failure  which    i-    not    of    a    strength    and 


1048 

quality  to  make  a  p>od  print.  This  may  he  of  the  -ame  size  as  the 
plate,  hut  it  is  verv  much  the  author's  custom  to  have  a  professional 
photographer  make  .">  x  7  or  S  \  10  inch  reduced  mounted  prints  on 
ulossy  paper  which  -how  all  the  details  like  a  steel  oimravinii,  and  are 
hound  together  as  a  folio  of  convenient  si/e  for  studying  the  entire 
series  and  for  lilinu  away  for  reference.  If  the  photographer  has  the 
equipment  assemhled  for  daily  use  these  prints  cost  loss  than  the  large 
ones. 

\<>tt  S.  Duplitixed  lilms  and  two  intensifying  screens  are  very 
tlesirahle  Tor  Castro-intestinal  radiography. 

IMPORTANT   LITERATURE  UPON   RADIOLOGY   OF   STOMACH  AND 

INTESTINES 

1  lol/knecht  ami  Case,  Amvendung  dor  Stereoskopie  fiir  die  Rfmtgenuntersuchung 
de<  Mairens  und  Darmes.  Vereinsbericht,  Mi'mcli.  mod.  Wochenschr.,  1911.  S.  280"). 

I\:n-tli'.  Die  Thorerde  Thorium  oxydat.  anhydr.  uns\v.  Miinch.  med.  Woehon- 
<chr.,  190s.  S.  2iHitl. 

Cannon.  The  Movements  of  the  Stomach  Studied  by  Means  of  the  Rontgen 
Ray-.  Amer.  .lourn.  of  Physiol.,  vol.  i,  1S9S. 

('«il<-  and  Finhorn.  I'hcr  Radiogrammo  des  Vordauungstraktus  nach  Luftoin- 
hlaMini:.  Wcin.  klin.-thcrap.  Wochenschr..  1911.  Xr.  ."i. 

(Irocilcl,  Die  Form  dcs  pathologischon  Matron^.  ,  Deutsclir  ined.  Wochenschr., 
1910.  Nr.  ir>. 

Haudck.  Zur  Rcintgonologischon  Diagnose  der  I'leer  itionen  in  der  Pars  Media 
des  Mairens.  Mimch.  ined.  Wochenschr.,  1910.  Nr.  30. 

Hol/.kneeht,  Die  neueren  Fortschritte  der  Rontgenuntersuchung  des  Verdau- 
uimstraktus.  Berl.  klin.  \\'ochensehr.,  1911.  S.  l."),s. 

Kae>tle,  I'her  Mageninotilitiitsprufung  mit  Ililie  der  Rontgestrahlen.  M.iinch. 
med.  \\Ochenschr..  1907. 

I'fahler.  The  Rcmtgeii  Rays  as  an  Aid  in  the  Diagnosis  of  Carcinoma  of  the 
Stomach.  .Jour,  of  the  Anier.  'Med.  Assoc..  1909,  Hd.  lii.  Nr.  11. 

Pfahler.  Roentgen  Rays  in  the  Diagnosis  of  (lastrieand  Duodenal  Ulcers.  Amer. 
(^uarTerly  of  [{oentgenology,  iv,  Feb.,  1913,  No.  3,  p.  l.~>ii. 

Ried'er,  Rontgenuntersuchungen  des  Magen>  und  Darnies.  Miinch.  med. 
\Vni-henM-hr.,  19011.  Xr.  3. 

Rieder,  Das  chronische  Mjigengesclnviir  und  sein  r(intgenologischer  Nachweis. 
Muneh.  med.  Woclienschr.,  1910.  Nr.  4S. 

!  laetii-ch.  Die  Rontgenuntersuchung  bei  \"erengmiiren  des  Dickdarms.  Rontgen- 
olnuisclie  l-'ri'ihdiamiose  de>  1  )ickdarmkarzinoms.  Miinch.  med.  Woehenschr..  1911.  S. 

Uaudj-k,  I),  r  Radiolouisclie  Nachweis  der  rieusduodeni.     Med.  Klinik,  1912.  Xr. 

Hul/knechT.  Die  Xonnale  I'eristaltik  des  Colon.  Miinch.  med.  Woclienschr.. 
190'.  i.  Nr.  17. 

.Itiii.-i-,  S..  I  'ber  die  Abhaniritdieit  der  Darmnn  it  ilii  ai  vom  \"erhalten  des  Magens 
11  \-tPii  <eiiiem  Saureii'rad  .  \\ein.  klin.  \\ochen-clir..  1911.  Nr.  22,  S.  777;  u. 
V.'-n-in-b..richt,  Munch,  med.  Wochensrhr..  1911,  S.  lo:,3, 

Ri'-der.   !')'•!'  riiii'-  /ur  'l"npogra])hie  de>  Magen-Darmkanales  u>\v.  l'"ortschr.,   Hd. 


niittel-   Rntitgen-trahlen.      \\Cin.med. 


perative     Thel'aple     Lre\\'l--ef     \ 


h  \Verer    (  >b.-1  ipat  ion. 


mobili'  und   diri  mi~clie  Ai)p''ndicii 


.   Kmmr    der   I)    g 


nd  f  .''onard.  The  Ri'int  tr«-n  Diatr 


URINARY     CALCULI 

I  rmar\    i-alcuh    m;i\-    very    otten    he    -hown    m    ;i    radio<rra])h.      If 

Mn".     i'lo    iidi     -how    m    ::    u'noil    picture    It     I-    not     po>lli\'e    proof    thai    they 

are  ;ih~c]it.  lor  -oine  oi   them.  con>i-imti  ot   iriahlo  pure  uric  acid,  have 


such  slight  density  that  they  make  no  contrast  with  tin-  tissues.  The 
denser  varieties,  even  il  <|ititr  .-tn;ill,  show  well  in  ;tn\'  picture  in  which 
the  detail  (A  the  vertebra1,  their  bodies,  spines,  and  t  raiisver.-e  ;md 
vertical  processes,  can  be  seen  together  with  the  last  ribs  and  the  quad- 
I'atus  luniborum  and  psoas  muscles.  To  obtain  such  ;i  picture  \\ith- 
out  danger  to  the  patient  requires  the  most  perfect  technir  and  fir.-t- 
dass  ap|>arat  us.  One  should  hesitate  to  at  tempt  such  a  pict  ure  unt  fl 
lie  has  acquired  such  practical  experience  with  the  .r-rav  that  lie  i- 
able  to  secure  excellent  radiographs  of  less  dillictilt  jiarts  witli  a  mod- 
erate st  relief  h  of  cui'rent  and  with  sliort  exposures.  The  first  case 
that  one  colleague  attempted  \\as  exposed  for  six  minutes,  nothiim 
on  the  photographic  plate;  and  again  for  sixteen  minutes  without  anv 
result  except  a  severe  burn.  To  secure  a  good  picture  of  this  region 
every  time,  instead  of  occasionally  as  a  sort  of  accident,  it  is  necessarv 
to  be  able  to  properly  excite  the  ./--ray  tube.  Kvery  word  in  the  chap- 
ter on  general  radiographic  technic  should  be  known  b\-  the  operator 
and  verified  and  mastered  by  repeated  experiment.  The  effort  should 
not  be  to  take  radiographs  in  the  shortest  possible  time,  but  rather 
to  take  the  best  possible  radiographs  and  in  the  safest  possible  wav. 
Calculi  may  be  in  the  pelvis  of  the  kidney,  in  the  ureter,  or  in  the 
bladder,  and  two  different  positions  of  the  patient  are  desirable1.  For 
those  in  the  kidney,  or  in  the  part  of  the  ureter  above  the  brim  of  the 
pelvis,  the  patient  should  be  lying  upon  his  back  with  the  plate  'measur- 
ing 14  x  17  inches)  placed  longitudinally  beneath  him  from  the  tenth 
dorsal  vertebra  to  just  above  the  trochaiiter.  The  patient'.-  knee- 
should  be  raised  and  the1  feet  rest  against  some  support,  the  effort 
being  to  bring  the  lumbar  vertebra^  into  contact  with  the  plate. 

A  large  fat  person  is  very  much  more  difficult  to  radiograph  than  a 
small  thin  person.  The  difficulty  does  not  appear  to  be  so  much  an 
impenetrability  of  the  body,  as  a  very,  much  increased  diffusion  of 
the  .T-ray,  or,  more  accurately,  an  increased  production  of  secondary 
rays.  The  use  of  a  diaphragm  and  cylinder  to  cut  off  the  secondary 
rays  from  the  .r-ray  tube,  with  or  without  compression,  is  of  great 
service  in  overcoming  this  difficulty. 

The  thickness  of  abdominal  tissue  through  which  the  .r-ray  mu-t 
penetrate  may  be  diminished  in  three  different  ways:  One  is  by  the 
use  of  an  air-filled  bladder,  which  is  pressed  upon  the  abdomen  by 
a  belt  passing  over  it  (Caldwell),  another  is  by  the  use  of  the  compres- 
sion cylinder  \. \lbers  Schonberg:.  and  the  third  is  by  the  Use  of  the 
'Hit hor's  board  com j iressor. 

The  compression  cylinder  (Fig.  To.)  produces  an  excellent  picture, 
bill  one  not  more  than  0  or  s  inches  in  diameter,  and  hence  a  single 
picture1  does  not  irive  conclusive  result-  in  cases  in  which  the  position 
of  (lie  calculus  or  even  its  very  existence  is  no!  known. 

The  Board  Compressor.1  —  Fqually  good  detail  is  obtained  with 
tlu1  author's  board  compressor,  and  it  has  the  very  great  advantage 
of  producing  a  picture  the  full  sixe  of  a  1  IX  17-inch  plate.  It  consists 
of  a  board  of  white  wood  1,  inch  thick.  Ill  inches  wide,  and  IN  indies 
long,  which  is  reinforced  at  either  end  by  cross-pieces  ,•',,-  inch  thick. 
The  cross-pieces  are  '2  indies  wide,  are  beveled  toward  the  middle, 
and  are  glued,  not  nailed,  on.  Two  holes  are  bored  through  each  of 
the  reinforced  ends  for  cords  pa--ed  under  the  table.  The  board 
1  Tuuscv,  Louisville  Medical  I'p>mv~.  November.  1 '.«>}. 


1050 


MKDICAL    ELECTRICITY    AND    UONTOKX    HAYS 

~"      " 


IL'.  7M  I. —Renal  radiography  \vitli  a  coinpies.-ion  cylinder.     The  knees  should  lie  drawn 
up  and  a  pillow  placed  under  the  shoulder.-  a-  in  Flu.  7 '•'>'>. 


I'enal    radioL'raphv    with    eonipre-.-iim    band,  under  which    is   an    inflate* 


ne  to  pui    the  plate  in  exactly  the  ritlht 


it]    ii       ;  late  tun 


. '    •  •    r  t  he  iiat  ient  and  to  i'li:i  ni/e  i'   for  -i 


'      "plntr-    tunnel."      Stroim   enotiirh    to    -u.~tain    the    patient's 


!,'-./•  rav.      Sr.  lari.re  tliat  the  plate,  u,  it  -  Imlder  \\  it  1,  ,,\-  without 


•     .        itii  inei  i   wit  hout    ino\  ini:   lli'     pa  i  i>  ill 


THE    Z-RAY 


1051 


pressed  tightly  across  the  abdomen  (Fig.  735),  making  a  reduction  of 
2  or  3  inches  in  the  thickness  through  which  the  x-ray  must  pass,  and 
is  itself  perfectly  transparent  to  all  but  the  softest'  rays.  As  these 
rays  are  the  ones  which  produce  dermatitis  the  board  compressor  fur- 
nishes an  element  of  safety. 

The  coniitre.wion  band  with  an  inflated  rubber  ball  is  easily  and  quickly 
applied  (Fig.  735).  This  is  better  than  the  board  compressor. 

Heavy  tungsten  target  tubes  are  necessary  for  this  work,  the  ( 'ool- 
idge  tube  being  excellent. 

A  14  x  17  inch  plate  is  placed  lengthwise  under  the  body,  with  its 
center  3  inches  above  the  umbilicus.  The  x-ray  tube  is  placed  with 
its  anticathode  over  the  umbilicus  at  a  distance  of  23  inches  from  the 
plate  and  inclined  so  that  the  principal  ray  is  not  vertical  but  is  directed 
toward  the  center  of  the  plate  as  above  described.  The  best  results, 


quire  a  small  diaphragm  and  only  one  kidney 


ith  a     as-filled  tube  r 


own.     With   the  (' 


e,   however,   the  author 


.  ,  , 

ses  no  diaphragm,  but  exposes  the  whole  of  the  I  I  \  17  inch  plate  at 
once.  In  patients,  however,  with  a  very  marked  disparity  between 
the  waist  and  hip  measurements  the  exposure  requires  to  l.e  equalized 
by  the  author's  graduated  .r-ray  filter,  reducing  the  intensity  at  the 
level  of  the  umbilicus  and  for  a  few  indie-  above  and  below  that.  This 
i-  -eldoin  required  for  men,  but  frequently  for  women. 

The  exposure  table  on  page  S(,)S  i>  ba-ed  upon  the  use  of  rays  cor- 
responding  to  a  (-inch  spark  and  upon  i  he  use  of  an  intensifying  screen. 
The  latter  may  be  dispensed  with  in  patients  so  thin  as  to  need  only 
short  exposures,  but  the  time  would  then  have  to  be  about  two  and  a 


10.J-'  MKlHi  Al.    Kl.Kl  TKK1TY    AM)    KONTCJEN     KAV 


Before  applying  compression  band  and  l>:ill  for  renal  radio<;rai)hy. 


hall  times  as  great.  This  would  lie  undesirable  for  the  heavier  patients 
because  the  very  long  exposure  with  this  quality  of  .r-rav  would  over- 
heal  the  tube  and  require  the  patient  to  hold  his  breath  too  lon<>. 

The  examination  should  only  be  undertaken  with  the  stoniaeh  and 
intestine  perfectly  empty  as  far  as  solid  food  or  any  milk  pr<  dud  is 
concerned. 

The  tube  must  be  excited  in  >uch  a  way  a>  to  produce  a  brilliant 
radiance,  as  viewed  with  t  h«  LI  Horoscope,  and  the  vacuum  ou»ht  to  be 


40. — Compression    relaxed    after   the    renal    radiograph    has   IMTII    mad 


shows  what  compression  had  been  exerted.       Patient   mu-t  -ay  when  thf  pressure  i-  all  h 


medium,  resistance  about  4  inches.  The  distance  from  the  target  to 
the  plate  should  be  2o  inches.  An  intensifying  screen  should  be  u>ed, 
and  for  an  ordinary  150-pound  man  an  exposure  of  '.\\H)  ma.  seconds,  for 
example,  30  ma.  for  thirteen  seconds  (see  exposure  table  for  sex.  weiuht. 
and  measurement  variations,  page  898\  \Vithoii1  an  intensify  ing  screen 
a  ")-inch  back-up  and  the  same  exposure  an-  u-ed. 

A  very  <lesii'able  technic  is  .1-inch  gap.  dupliti/ed  film. '_'  intensifying 
screens,  and  2  thicknesses  of  tin  to  arre-t  secondary  ./'-ray-  arising  from 
the  t  issues. 

Tlu1  extremely  powerful  trail-former  currents,  described  on  p.  "111. 
permit  of  exposures  of  about  one  second.  The  current  should  lie  >hut  off 
during  si  long  weak  exposure  in  time  to  prevent  t  lie  t  ube  t  n>m  lieconiing 
overheat ed  and  after  a  minute's  pan-^e  l  urned  on  auam.  It  will  be  remem- 
bered that  t  here  are  t  wo  danger-  from  overheating  the  ant  icathode  max 
be  burnt  through  or  the  vacuum  may  become  excessively  low.  It  is  wise 
to  have  a  not  her  t  ube  in  readiness  and  to  wat  ch  the  behavior  of  t  he  tube 


1054  MEDICAL    ELECTKICITY    AND    RONTGEN    RAYS 

in  use.  If  the  tube  becomes  useless  the  second  tube  should  be  sub- 
stituted, taking  care  that  its  anticathode  shall  be  at  exactly  the  same 
point,  directly  above  the  umbilicus,  as  the  first.  For  the  bladder  and 
the  portion  of  the  ureter  below  the  brim  of  the  pelvis  the  patient  lies 
Hat  on  his  back,  with  the  limbs  extended,  and  sufficient  cushions  under 
his  hack  to  tilt  the  pelvis  somewhat  forward.  The  anticathode  should 
be  vertically  above  a  point  o  inches  below  the  umbilicus.  In  this 
position  the  rays  pa-s  down  through  the  pelvic  canal,  and  any  cal- 
culus present  is  seen  free  from  the  shadow  of  the  bones.  The  distance 
of  the  tube  from  the  plate,  the  degree  of  vacuum,  and  length  and  in- 
tensity of  the  exposure  an1  the  same  as  for  renal  calculi.  The  com- 
pression board  is  used.  Following  the  author's  almost  invariable 
practice  in  radiography  a  shield  of  .r-ray  metal  (tin  and  lead)  is  placed 
behind  the  plate  to  shield  it  from  secondary  rays  arising  from  the 
Wood  or  other  parts  of  the  table  or  from  different  objects  in  the  room. 

Riddel1  uses  the  fluoroscope  as  a  preliminary  to  radiography  in 
examining  for  urinary  calculi,  but  this  is  extremely  dangerous. 

The  plan  of  having  the  patient  lie  face  do.vn  upon  a  canvas  stretcher 
or  thin  board  table,  with  the  tube  underneath  the  abdomen,  enables  one 
to  make  a  fluoroscopic  examination  for  renal  or  ureteral  calculi.  The 
iluoroscope  is  held  over  the  patient's  back.  The  tube  may  be  held  by 
the  orthodiagraph,  or  it  may  be  completely  enclosed  in  an  opaque  shield, 
such  as  Ripperger's.  I'sing  the  latter  with  the  largest  diaphragm  and 
the  anticathode  at  a  distance  of  25  inches  from  fluorescent  screen,  the 
whole  of  both  kidney  and  ureter  regions  and  the  bladder  become  visible 
at  once.  Any  large  calculus  may  be  discovered  by  an  eye  trained  to 
thi-  phase  of  fluoroscopy.  and  may  be  subjected  to  more  exact  scrutiny 
with  a  smaller  diaphragm  or  cylinder,  or  with  the  author's  cellular 
diaphragm.  The  protective  shield  prevents  injury  to  the  operator's 
limbs  or  genitals,  and,  if  the  room  is  entirely  darkened  and  the  fluoro- 
scopic screen  covered  by  a  sheet  of  lead-glass,  his  face  and  eyes  are  also 
protected.  A  radiograph  may  be  made  of  the  whole  region,  or  a  smaller 
one,  with  a  diaphragm  or  cylinder,  may  be  made  of  a  stone  located  by 
iluoroscopy.  The  dangers  to  the  operator  are  so  great  that  even  these 
precautions  will  not  make  it  safe  to  use  frequently. 

The  danger  to  the  patient  must  be  remembered,  and,  if  the  localiza- 
tion of  a  calculus  with  the  fluoroscope  is  evidently  going  to  take  more 
than  a  very  few  seconds,  the  operator  should  stop  and  at  once  proceed 
to  make  a  ra<  liograph. 

This  prone  position  produces  more  or  less  natural  compression  of  the 
abdomen,  and  the  compression  may  be  increased  by  placing  an  air-bag 
of  some  kind  upon  the  table  under  the  abdomen.  Compression  by  the 
compression  cylinder  is  not  practicable  in  this  position. 

ir  the  Madder  and  the  lower  part  of  1  he  ureters  the  plate  is  placed 
he  center  is  .'!  inches  below  the  umbilicus  and  the 
icy,  and  a   11  x  17  inch  plate  is  Used  and  the 
-   center.     The   compression    band   and   bag 
e    -ame    possible    desirability    of   the   author's 
|Uali/.e  the  expo-ure  if  the  waist   i- 


Locations   in   Which   to   Look   for   Urinary   Calculi.      Renal    calculi 
.  -   .  found    near    tin-    an 

•  r.l.-i-L'mv  M.-. 


THE  X-RAY 


105.-) 


to  the  border  of  the  spine.  If  they  are  much  below  this  region,  it  is 
because  of  displacement  of  the  kidney,  and  suspicious  sh;ido\vs  beyond 
the  tip  of  the  twelfth  rib  ;ire  almost  always  of  intestinal  origin. 

Ureteral  calculi  are  most  often  found  below  the  brim  of  the  pelvis. 
The  course  of  the  ureter  may  be  indicated  by  a  line  starting  1  inch 
internal  to  the  spine  of  the  pubis  and  extending  to  the  sacro-iliac 
synchondrosis.  But  this  position  miuht  be  misleading  in  case  of  a 
calculus  sacculatcd  at  some  distance  from  the  ureteral  lumen  (Tilden- 
Brown). 

A  radiograph  made  with  Ihe  tube  over  a  point  midway  between 
the  umbilicus  and  the  symphysis  pubis,  and  with  the  anticathode 


[•  ig.  ill.  —  Iso   of    FOUSPV  s   radiating   cellular  rhanhraprn    in   radiography   nf   renal 


calfuli.      Weight  of  patient,  15<S  pounds.      Induction-coil,    1s* 


divided  exposure.      I.umiere  .r-ray  plate.      This  apparatus  lias  heen  abandoned  because  it 


required  fluorosropic  adjustment  and  was  dangerous  ID  the  operator 


about  10  inches  from  the  surface  of  the  abdomen,  will  avoid  casting  the 
shadow  of  the  ureters  upon  the  sacrum,  where  it  miiiht  be  difficult  to 
recognize  the  shadow  of  a  stone. 

Among  U  cases  of  ureteral  calculus  reported  by  A.  T.  ('a bop  the 
>tone  was  lodged  at  the  junction  of  upper  and  middle-third-  in  one 
case,  2  were  lodged  at  the  lower  part  of  the  middle  third,  and  (i  in  the 
lower  third  of  t  lie  ureter. 

In    Haetjer's  .'$.")!    cases  examined   for   urinary  calculus  only  o  ca-es 
revealed  a  ureteral  calculus  lyinu;  above  the  brim  of  the  pelvi-. 
1  Boston  Mi-.l.  ami  Surt;    Jour  .  ]'.'•<)'>. 


MKDICAL  Ki.KrTKKiTY  AND  RONTGEN  HAYS 

The  Use  of  the  Cylinder  and  Diaphragm  in  Radiography  of 
Renal  and  Ureteral  Calculi. — A  small  cylinder,  3  inches  in  diameter 
and  7  inches  long,  extending  from  the  surface  of  the  patient's  body 
to  the  localizing  shield,  or  opaque  box  enclosing  the  .r-ray  tube,  makes 
the  di.-tancc-  from  the  anticathode  to  the  photographic  plate  about 
2~>  inches.  The-  diameter  of  the  picture  is  (j  inches,  and  a  really  wonder- 
ful improvement  in  definition  is  obtained  compared  with  the  results 
when  no  diaphragm  at  all  is  used.  Careful  study  will  enable  one  to 
secure  a  picture  of  the  exact  region  of  the  kidney,  an  S  X  10-inch  plate 
being  required.  By  applying  the  cylinder  at  first  a  little  to  one  side 
of  the  median  line,  and  then  to  the  other,  both  kidney  regions  may 
be  radiographed  without  exposing  the  same  tissues  twice  to  the  x-ray. 
A  single  radiograph  with  the  same  small  cylinder  in  the  median  line 
and  2  inches  above  the  symphysis  pubis.  and  tipped  a  little  downward, 
will  show  the  whole  cavity  of  the  pelvis  and  reveal  calculi  in  the  bladder 
or  in  the  pelvic  part  of  the  ureter.  One  made  with  a  cylinder  5  inches 
in  diameter  in  the  median  line.  3  inches  above  the  symphysis  pubis, 
will  show  the  middle  portion  of  both  ureter.1. 

Stereoscopic  radiography  may  be  occasionally  used  in  the  differ- 
ential diagnosis  of  renal  calculi.  Filling  the  bladder  and  rectum  with 
oxygen  gas  still  further  increases  the  clearness  of  the  image. 

It  is  rather  important  to  make  certain  that  the  patient  has  not  been 
taking  bismuth  for  a  few  days  before1  such  an  examination.  This 
would  cause  a  shadow  which  might  be  mistaken  for  that  of  a  calculus. 

Dense  cicatrices  in  the  kidney  have  been  seen  by  Baetjer  to  cause 
suspicious  shadows  similar  to  those  of  calculi. 

Dark  shadows  on  the  plate  or  light  areas  in  the  print,  presenting 
a  size,  shape,  and  position  suggestive  of  urinary  calculi,  must  not  be 
mistaken  for  them.  They  may  be  due  to  one  of  two  different  causes: 
fir.-t,  an  imperfection  in  the  plate;  second,  a  collection  of  gas  in  the 
rectum  or  some  other  part  of  the  intestines.  These  shadows  represent 
areas  of  reduced  resistance  to  the  .r-ray,  and  cannot,  therefore,  be  due 
to  calculi,  which,  of  course,  cause  increased  resistance. 

The  last  ribs,  the  crest  of  the  ilium,  the  transverse  processes  of  the 
lumbar  vertebra-,  and  the  edge  of  the  psoas  muscle  should  all  be  clearly 
defined  in  a  radiograph  to  fit  it  for  the  diagnosis  of  urinary  calculi. 

Differential  Diagnosis  of  Urinary  Calculi.-— Very  often,  but  not  al- 
ways, one  can  be  sure  from  the  location  and  form  of  the  foreign  body 
that  it  is  a  renal  or  a  ureteral  calculus.  One  means  of  value  in  case  of 
doubt  is  the  author's  method  of  localization  of  foreign  bodies.  Applied 
in  the  case  shown  in  Fig.  712  this  showed  the  foreign  body  to  be  3 
inches  from  the  plate  and  in  the-  kidney  shadow.  This  proved  that  the 
foieiu-n  bodv  was  in  the  kidney.  When  ureteral  calculi  are  apparently 
-hown  an  opaque  ureteral  catheter  is  introduced  and  two  radiographs 
made  with  the  tube  displaced  laterally.  If  the  catheter  is  in  the  same 
i-lo-c  contact  with  the  foreign  body  in  both  radiographs  the  latter  is 
do  ibtle-s  in  the  ureter.  Figure  713  showed  that  the  concretions  were 
not  in  the  ureter,  but  were  doubtless  phleboliths  and  not  responsible 
t'  >r  t  he  p.-i  t  ient  's  symptoms. 

Penetrability  of  Different  Kinds  of  Calculi.  The  order  of  pene- 
trability !  v  the  /-ray  is:  1,  Biliary  calculi;  2.  uric  acid  calculi;  3,  phos- 
pha  '  ic  c-i  l.'uli ;  1 .  calcium  oxalate  calculi. 

Th'1-r  |e.-|st  permeable,  like  the  calcium  oxalate  calculi,  cast  the 
deep,-;  -h:ido\v-.  and  are  the  most  easy  to  detect. 


I'ric  acid  calculi  cast  faint  shadows,  but  can  almo.-t  always  he 
detected  in  a  successful  radiograph.  I'hosphatic  and  calcium  oxalate 
calculi  cast  dense  shadows,  and  can  always  he  ,-een  in  a  .-ucce.-sful 
radiograph  unless  they  are  very  small.  A  calculus  .-mall  enough  to 
be  passed  in  the  urine  may  e.-cape  detection  by  the  r-ray,  e.-peciallv 
if  the  pat  lent  is  lar»;e  or  stout . 

The  order  of  permeability  corresponds  fairly  well  with  the  specific 
if  the  patient  is  larjre  or  stout. 

('ystin  and  xanthin  calculi  have  shown  perfectly  well  in  a  num- 
ber of  radiographs  by  Morris.1  This  may  he  due  to  the  fact  that  many 


of    these    calculi    contain    calcium,    maune-mm.    and    ammonium    phos- 
phate, and  1  hey  will  contain  '2't  per  cent,  of  sulphur. 

Phleboliths.-  These  small  concretions  are  very  apt  to  occur  in 
the  veins  o!  the  pelvis,  and  can  sometime.-  be  seen  in  a  radiograph. 
Their  shadow-  are  more  definite  and  then  edsie-  are  more  sharply  de- 
fined than  those  of  a  calculus,  and  they  are  almo-1  always  very  small. 
They  lie  close  to  the  line  of  the  ureter  at  or  helow  the  brim  of  the  pelvi-. 

1  Lancet.  July  L'l,   I'.Klti. 

157 


1UO»  MEDICAL    ELECTKKTTY    AND    KONTGEN    KAYS 

In  cases  of  doubt  another  radiograph  should  be  made  with  a  ureteral 
catheter  in  position.  The  phlebolith  will  be  found  to  the  outer  side  of 
the  catheter. 

A  soft  flexible  ureteral  catheter  has  been  devised  by  Fenwick, 
and  has  also  been  used  by  Howard  A.  Kelly  for  cases  of  this  kind. 
It  contains  a  certain  percentage  of  bismuth,  and  is  safer  to  use  than 


• 


1  iir.  74I-1 


h  of  un'tcr.-il  catheter-  dcmoiist  nitinir  plif.-l  i  Jit  hs,  not   im-tora!  cal- 


a  c;jt hetrr  with  a  mHal  >ty]et.     A  cat heter  int o  which  a  cert ain  amount 
"t    niftnllic  mercurv  h;i-  been   poure-d   is  equally  good   tor  this  purpose, 

-  tint   -d  -implc  as  the  catheter  impregnated  with  bismuth. 

The     Ureteral     Catheter     in     Radiography.     A     ureteral     catheter 

rendi-fcd     .p.-tque  ;is  above  may  be  int  roduccil  ;i>  ;m  ;iid   in  the1  radio- 

gi'aphir  d];iLi!ii  i-i-  of  ureter;d  ;ind  renal  condition-.      iJamskj'    used  this 

mrtliod  -Hi''-'----!  i|]|\    in  _'  most    interesting  cases.      In  one  patient   a  sim- 

ftn.  .lulv  !»,   I'.Kl."). 


THK    .f-KAY  1059 

pie  radiograph  had  shown  a  kidney-shaped  body.  The  radiograph,  made 
\vith  a  ureteral  catheter  and  stylet  in  position,  showed  that  these  did 
not  pass  into  th'  kidney-shaped  body.  It  was  concluded,  therefore, 
that  this  Avas  not  the  kidney,  and  upon  operation  it  was  found  to  bo 
an  ovarian  cyst  with  an  extremely  long  pedicle.  The  other  ca.-e  was 
that  of  a  woman  with  a  ureteral  fist  ula  following  the  removal  of  a  uterine 
fibroid.  A  radiograph,  made  with  catheters  in  both  ureters  and  the 
fistula,  showed  which  ureter  had  been  opened  and  at  "what  level. 

A  ureteral  catheter  containing  metal  wire  will  show  in  a  radio- 
graph. Pransford  Lewis'  reports  a  case  in  which  three  ureters  were 
demonstrated  in  this  way. 

The  ureteral  catheter  will  also  aid  in  deciding  whether  a  shadow 
on  the  plate  is  due  to  a  calculus  or  to  something  outside  of  the  ureter. 
Fen  wick2  reports  cases  in  which  the  radiograph  showed  bodies  apparently 
in  the  ureter,  but  a  second  radiograph  with  a  ureteral  stylet  showed 
that  such  was  not  the  case.  The  operations  showed  that  the  shadows 
were  those  of  calcined  lymphatic  glands  or  arteries. 

Technic  of  Ureteral  Catheterization  (Dr.  Palph  Tousey.  Personal 
Communication). —  The  catheters  are  >1erili/ed  by  washing  with  green 
soap  and  water,  placing  them  in  soon  bichlorid  of  mercury  for  an  hour 
or  two,  then  in  2  per  cent,  boric-acid  solution.  They  are  dried  and 
kept  dry.  If  they  are  to  be  used  soon  keep  them  in  boric-acid 
solution.  The  stylets  may  be  boiled  or  passed  through  an  alcohol 
flame  and  kept  temporarily  in  boric-acid  solution.  The  metallic  in- 
struments are  sterilized  by  washing  in  alcohol.  Local  anesthesia  is 
secured  in  1  he  female  by  filling  1  he  uret  hra  with  '20  minim-  of  ^  per  cent, 
solution  of  cocain  from  a  hypodermic  syringe  without  a  needle,  leaving 
the  solution  in  for  three  minutes,  and  in  the  male  by  the  instillation  of 
.">  or  !()  minims  of  1  per  cent .  sol  ut  ion  of  eucain  in  the  prostat  ic  urethra. 
(  dycerin  is  used  as  a  lubricant. 

For  the  Xit/e  type  of  cystoscope,  for  instance,  the  Brown-Buerger, 
the  patient  is  in  the  dorsal  position,  with  the  legs  supported  by  crutches. 
Six  ounces  of  2  per  cent,  boric-acid  solution  i-  injected  into  the  bladder 
through  a  flexible  catheter,  which  is  withdrawn,  and  then  the  catheter- 
i/.ing  cystoscope  is  introduced.  The  perforated  caps  of  the  latter  are 
already  provided  with  the  two  catheters,  the  other  end.-  of  which  are 
held  at  a  higher  level  by  the  patient  or  nurse.  The  orifice  of  one  ureter 
is  to  be  sought  obliquely  outward  and  backward  \\  inches  di-tant 
I ron i  the  urethra,  and  a  number  of  blood-vessels  will  be  seen  to  radiate1 
from  it.  Push  the  corresponding  catheter  in  until  its  tip  is  seen,  and 
further,  until  the  tip  di-appear-  beyond  the  field  of  vi-ion.  See  the 
ureter,  bend  up  the  catheter  with  the  lever  provided  for  the  purpose 
until  the  tip  of  the  catheter  is  seen;  pu-h  the  entire  instrument  toward 
the  catheter  and  the  catheter  will  probably  enter  the  ureter.  When  in 
pu>h  the  catheter  a  couple  of  inche.-  further  into  the  ureter,  and  -wing 
the  instrument  over  to  the  other  side  and  introduce  a  catheter  into  tin1 
other  ureter.  The  urine  may  be  collected  in  two  sterile  test-tube-  for 
ten  or  fifteen  minute-.  Pu-hinu  the  catheter.-  in.  the  pelvi-  of  the 
kidney  will  be  entered  at  a  di.-lance  of  about  ^0  cm.  from  the  internal 
urethral  orifice;  this  will  be  evidenced  by  a  certain  obstruction,  also 
perhaps  by  the  ex-ape  ot  a  dram  of  urine  at  once  instead  of  the  ureteral 
peri-tal-i-.  The  capacity  of  the  pelvi-  i-  about  2  drams. 


101)0 

The  Howard  Kelly  cystoscope  is  simply  an  open  hollow  cylinder 
introduced  into  the  air-filled  female  bladder  and  directly  exposing  the 
ureteral  orifice,  which  appear-  of  its  natural  si/e  instead  of  being  magni- 
fied eight  time-,  as  in  the  Brown-Buerger  cystoscope.  Patient  on  her 
back,  with  feet  in  Mirrups.  cocain  is  applied,  the  bladder  is  emptied  by 
a  catheter,  the  urethra  is  dilated  by  passing  No.  20  Hanks  cervical 
dilator.  Then  the  knee-chest  position  is  assumed,  buttocks  on  a  plumb- 
line  with  the  calve>.  thighs  a  little  back  of  the  perpendicular.  Draw 
back  the  perineum  with  the  finger  to  allow  the  vagina  to  balloon  out : 
in  some  exceptional  cases  introduce  a  rectal  speculum  for  a  moment. 
Introduce  a  Kelly  cystoscope.  25  French,  with  electric-light  attachment. 
1  )epre--  handle,  bladder  filling  with  air.  Draw  out  to  internal  urethral 
orifice,  then  push  in  for  I1,  inch  with  a  lateral  deviation  of  30  degrees  and 
see  t  he  orifice  » if  <  me  ureter. 

A-  a  prophylactic  after  cystoscopy  2  ounces  of  2  per  cent,  solution  of 
protargol  are  injected  into  the  bladder. 

In  case  of  doubt  the  author  makes  two  radiograph-  from  somewhat 
different  directions.  ( 'oincidence  of  the  shadows  of  the  ureteral  catheter 
and  foreign  body  in  both  pictures  shows  that  the  foreign  body  lies  in  the 
ureter. 

I)<-i'(-lopment  of  the  plate  to  show  renal  calculi,  (i.  Thurston  Hol- 
land/ working  with  an  induction-coil,  mercury  interrupter,  and  an  ex- 
posure of  five  to  twenty  seconds  with  a  primary  current  of  7  amperes 
ami  an  I  If  on  1  .r-ray  plate,  found  that  six  minute-'  development  was  best . 
The  Ilford  metol  hydroquinone  formula  was  used  and  the  finished  and 
dried  plate  was  not  blackened,  but  white  and  lliin  and  easily  seen  through 
by  daylight .  The  detail-  of  the  abdominal  tissue-  and  the  vertebra1  and 
iliac  crest-  should  be  quite  clear.  This,  it  will  be  seen,  is  decidedly  differ- 
ent from  the  development  commonly  given  a  -creen  plate  of  the  stomach 
or  inte-tine-  containing  bismuth,  which  i.-  so  much  denser  than  a  renal 
calculus  and  where  the  plate  is  usually  decidedly  blackened. 

Results  in  Renal  and  Ureteral  Radiography. — A  mistake  in  diagno- 
si-  i-  po--ib'le  in  exceptional  cases  even  in  the  most  expert  hands,  but  in 
general  it  form-  an  extremely  reliable  ni"ans  of  diagnosis. 

Pirown'-'  mentions  a  case  in  which  the  radiograph  failed  to  show  a 
iireteral  calculus  which  could  be  seen  with  the  cystoscope.  and  which 
was  subsequently  removed  bv  an  operation. 

Lydstotr  reports  several  cases  of  ureteral  and  renal  calculi  removed 
by  operation.  >ome  of  these  were  found  in  the  skiagraph,  but  in  fully 
as  manv  other  cases  1  hev  were  not. 

The  r-ray  uave  negative  results  in  a  case  reported  by  Ware.4  The 
i--i->'  was  one  ni  contracted  bladder,  and  ai  a  postmortem  examination 
a  -lone  was  found  in  each  ureter  close  to  the  bladder. 

I  he  late   1'iMen  Brown1'  found  that  in  cases  of  pure  uric-acid  stones  a 
live  radiograph  was  as  likely  as  not   to  be  returned  by  the  ratliog- 
raphcr.  ami  tin-,  too,  in  subjects  of  favorable  pro  port  ions  and  where  t  he 
iii'e-imal  contents  are  thorotighlv  removed. 

lifi'ii  It.iv.  Jan..  I'.Mi'.i. 
N    ^     M'-'i..  A'-.d'.  <;.  T.  Section,  ( )ct.  17,  I'.HK1,;  Jour.  AIIHT.  Mcd.  Assoc.,  Doc. 

i.'.    I'.MMi.    |,      1J01. 

•I"   .'        \      ,•    '       M<  .]       V-MC   .     I'.XIf,. 

•      •     '  '     :    J.-ir  .   M.-.n-l,  :',!,  I'.tO'i.  ,,.  list 


THE    .T-KAY  1001 

Baetjer1  reports  a  successful  use  of  the  .r-ray  in  pract  ically  all  of  '.]')[ 
cases  examined  for  urinary  calculi. 

The  author's  own  cases  include  a  number  in  which  a  positive  diag- 
nosis of  calculus  was  made  from  the  radiograph.  All  but  one  of  these 
are  known  to  have  been  operated  on  and  the  calculi  removed.  The 
one  case  known  not  to  have  been  operated  on  made  the  most  beautiful 
picture;  of  all.  The  patient  was  referred  to  the  author  by  Dr.  I.eroy 
Broun,  and  a  radiograph  showed  a  collection  of  stones,  like  a  bunch 
of  grapes,  in  the  left  kidney.  Since  the  pain  and  tenderness  had  always 
been  on  the  right  side,  a  second  radiograph  was  made,  placing  a  dis- 
tinguishing mark  on  the  right  side  of  the  plate.  This  again  showed 
the  group  of  calculi  in  the  left  kidney.  The  pictures  are  decidedly 
different,  showing  either  a  different  grouping  of  the  calculi  or  a  differ- 
ence in  their  position  relative  to  that  of  the  .r-ray  tube.  Dr.  Broun 
lost  sight  of  the  patient  for  a  number  of  years  because  the  man  was 
afraid  to  be  operated  upon.  A  radiograph  (Fig-  741),  made  at  the 
end  of  that  time,  showed  a  similar  condition. 

A  curious  case  of  the  author's  was  one  in  which  the  radiograph 
showed  a  calculus  which  the  operator,  Dr.  Gallant,2  found  embedded 
in  the  mesentery  2  inches  from  the  ureter.  It  had  all  the  character- 
istics of  a  ureteral  calculus. 

Another  case  had  been  subjected  to  thirteen  x-ray  examinations 
before  being  brought  to  the  author  by  her  physician,  Dr.  W.  Travis 
(libb.  Six  or  seven  of  these  had  been  made  in  Kngland,  and  revealed 
a  ureteral  calculus  which  had  been  passed  spontaneously.  The  re- 
mainder of  the  radiographs  had  been  made  in  America.  Xone  of  the 
entire  thirteen  radiographs  showed  a  renal  calculus,  although  there 
were  well-marked  symptoms  of  such  trouble.  This  kidney  was  known 
to  be  prolapsed  and  the  other  kidney  had  been  removed.  The  radio- 
graph was  made  in  the  author's  usual  manner,  without  any  extra 
intensity  of  radiance  or  extra  length  of  exposure,  and  revealed  the 
presence  of  a  large  renal  calculus,  presenting  two  horn-like  prolonga- 
tions downward.  Smaller  pieces  were  visible  around  it.  1  he  stones 

to  cor- 


Should the  Surgeon  be  Given  the  Radiograph  or  Should  He 
Simply  be  Given  the  Radiologist's  Report  of  His  Examination?- 

The  last  case  is,  one  in  point.  The  radiologist  who  had  made  the  last 
examination  previous  to  my  own  had  refused  to  let  the  surgeon  have 
the  radiograph,  but  simply  stated  that  it  showed  that  no  stone  was 
present.  The  subsequent  result  showed  that  this  opinion  was  incorrect. 
and  that  if  it  had  been  acted  upon  the  patient  would  have  been  left 
to  suffer  from  this  very  painful  condition. 

It    is.   I  believe,   the  opinion  of  a   majority  of  the  active  members 
of  the  American   KontLren    Kay   Society  that    the   radiologist  is  to  uive 

from   which    the  surgeon   can  make   his. 
theory    that    the    radiograph   requires, 


his  opinion  and  not    a   pic 


1()»)2  MEDICAL    ELECTRICITY    AND    K(")NT(iEN    HAYS 

radiographs  of  the  different  conditions  which  ho  is  called  upon  to  treat, 
and  should  be  able  to  judge  of  the  quality  of  the  picture.  If  it  is  a 
mere  foggy  daub,  when  he  knows  that  a  good  radiograph  should  show 
the  lateral  processes  of  the  lumbar  vertebra"1,  he  is  not  obliged  to 
take  the  radiologist's  diagnosis  and  run  the  risk  of  performing  a  serious 
operation  uselessly  or  of  neglecting  to  perform  an  operation  in  a  case 
which  requires  it . 

The  surgeon  will  doubtless  accept  the  radiographer's  diagnosis 
in  almost  every  ea.-e.  but  he  should  have  every  opportunity  of  knowing 
\vhether  this  opinon  is  based  upon  a  successful  radiograph  or  not. 

In  some  cases  the  surgeon  has  made  a  special  study  of  the  radio- 
graphic  appearance  of  a  particular  class  of  lesions,  and  his  opinion  may 
be  even  more  valuable  than  that  of  the  radiographer.  The  author 
has  learned  a  great  deal  from  friends  who  have  sent  him  cases  to  be 
radiographed  because  they  have  not  the  time  to  devote  to  the  technic 
manipulation  of  ./--ray  apparatus. 

In  one  case  of  the  author's  two  plates  wore  exposed  at  the  same 
time  and  both  showed  excellent  detail.  One  showed  an  image  like 
that  of  a  calculus  somewhat  below  and  external  to  the  region  of  the 
kidney.  The  image  did  not  show  on  the  other  plate,  and  the  proba- 
bility seemed  that  it  was  due  to  some  defect  in  the  first  plate.  Dr. 
Douglas  II.  .Stewart  operated,  however,  and  found  a  calculus  in  the  posi- 
tion indicated  by  the  first  plate. 

A  considerable  number  of  cases  have  been  examined  by  the  author 
in  which  the  radiograph  showed  no  stone  in  the  kidney  or  ureter.  As 
far  as  he  knows,  none  of  these  cases  have  been  operated  on  and,  there- 
fore, it  is  impossible  to  say  whether  the  negative  diagnosis  was  correct 
in  all  of  these  or  not. 

The  late  ( 'has.  Lester  Leonard  and  Lewis  ( iregory  Cole  have  reported 
a  large  number  of  cases  examined  by  them  for  renal  and  ureteral  calculi 
with  excellent  results.  Leonard  formerly  gave  a  long  exposure,  four  or 
five  minute-,  with  a  moderate  intensity  of  radiation,  but  later  used  a 
transformer  and  an  exposure  of  only  a  few  seconds.  Cole  uses  a  short 
expo-ure,  about  half  a  minute,  with  great  inten-ity. 

A-  to  the  degree  of  penetration,  the  late  Dr.  (  'aldwell  used  a  ray 
wit  h  which  t  lie  bones  of  the  hand  appear  gray.  (The  use  of  the  hand  as 
a  radiometer  is  a  most  dangerous  practice.) 

Some  of  the  author's  best  radiographs  of  the  pelvis  and  lumbar 
reirion  have  been  made  with  a  penetration  of  only  Xo.  4  Benoist,  with 
which  the  bones  of  the  hand  would  appear  almost  black  on  fluoroscopic 
examinat  ion. 

<  IMP  ca.-e  was  examined  for  calculus,  and  the  very  distinct  image 
of  the  kidney  was  regarded  as  sufficient  evidence,  taken  together  with 
the  hi-torv  of  the  case,  to  require  an  exploratory  operation.  The 
operator.  Dr.  Tucker,  found  a  prolapsed  kidney  in  a  state  of  chronic 
r  mmation.  requiring  removal  <>f  the  entire  organ.  There  were  no 
ud  no  calcareous  foci. 

HYDRONEPHROSIS 

-  ease  produces  an  abnormal  appearance  in  the  radiograph. 
An  area  of  opacity  may  be  seen  to  begin  in  the  kidney  region  and  ox- 
tend  '  •  ;  and  perhaps  inward  from  it.  It.-  regular,  sharply- 

ilefincd,  conv    .  bonier  and  largo  size  are  its  chief  characteristics.    These 


THK    X-RAY 

may  not  enable  one  to  make  more  than  a  probable  diagnosis  of  hydro- 
nephrosis,  but  they  do  exclude  renal  calculi  or  biliary  calculi  (a.-:  the 
sole  lesion),  tuberculosis  of  the  kidney,  or  intestinal  obstruction. 

Report  on  the  Radiographic  Findings  in  a  Case  of  Hydro- 
nephrosis. — The  patient  was  sent  to  me  through  the  kindness  of 
Dr.  Beaman  Douglas,  (lull-stone  disease  \vas  suspected  from  the  symp- 
toms of  attacks  of  pain  and  tenderness  and  from  the  presence  of  a 
tumor  in  the  gall-bladder  region.  A  radiograph  was  made  after  an 
ordinary  dose  of  Kochelle  salt,  and  another  a  fe\v  days  later,  after 
very  thorough  purgation  by  llunyadi  water  and  fasting  for  twenty- 
hours.  The  following  is  an  abst  ract  of  my  report  on  the  radiographs: 

"The  two  pictures  are  practically  identical.  They  show  the  ab- 
senc?  of  any  lenul,  ureterul,  or  vesicul  calculus,  and  they  show  an  area 
of  quite  dense  opacity,  extending  downward  and  inward  from  the 
right  lobe  of  tin'  liver  to  the  median  line  at  the  level  of  the  crests  of  the 
ilia.  The  right-hand  border  of  this  area  of  opacity  is  very  sharply 
defined,  and  forms  an  unbroken  line,  which  makes  the  right  side  of 
the  abdomen  in  the  radiograph  contrast  greatly  with  the  left  side.  We 
see  on  the  left  side  a  more  or  less  irreu'ular  and  broken  border  to  tin- 
shadow  of  the  abdomen.  The  area  of  opacity  on  the  right  side  obscures 
the  lower  ribs  on  that  side  and  also  a  part  of  the  vertebra;.  A  mass 
of  gall-stones  would  not  be  expected  to  cast  so  decided  a  shadow,  and 
certainly  not  one  with  such  a  clearly  defined  border.  The  opacity 
would  indicate  the  presence  of  either  a  large1  sac  of  fluid  or  of  a  solid 
tumor.  There  appears  to  be  very  little  doubt  as  to  the  necessity  of 
surgical  exploration  in  this  case.  It  cannot  be  stated  whether  there 
an1  any  gall-stones  present  at  all,  and  they  certainly  do  not  form  the 
bulk  of  the  swelling  which  is  felt  on  abdominal  palpation," 

The  operation,  performed  by  a  surgeon  in  Portland,  Maine,  evacu- 
ated a  lunre  sac  of  fluid,  which  at  first  appeared  to  be  a  retroperitoneal 
cyst,  but  from  which  urine  began  to  flow  in  a  few  days,  proving  that  the 
trouble  was  hydronephrosis. 

PYELOGRAPHY 

Yolcker  and  Lichtenberg1  puss  a  ureteral  catheter  into  the  kidney 
and  inject  u  warm  (5  per  cent.)  solution  of  collargol  (a  silver  compound') 
into  its  pelvis.  The  size  and  shape1  of  the  pelvis  of  the  kidney  can  then 
be  shown  in  a  radiograph.  The  method  is  suggested  for  the  diagnosis 
of  dilatation  and  of  deformity  of  the  ureter. 

PERINEPHRITIS 

The  .r-ray  gave  negative  results  in  a  cast1  of  paranephritic  sclerosis 
operated  upon  by  Berg." 

HEMORRHAGIC   NEPHRITIS 

Hemorrhagic  nephritis  was  present  in  -  cases  reported  by  Wiener.3 
The  radiographs  showed  no  abnormal  appearance  of  the  kidney,  ureter, 
or  bladder. 

1  Munch.  Mc,l.  Woch.,  Jan.  K>.  I'.iOf.. 

2  N.  "i  .  Mcd.  Jour.,  Aim.  IS.  I'toti. 

3X.Y.  Acud.    M«'d.   Cfiiito-l'i-iiuiry   Section,   Oct.  17,  1 '.»()»'.;   N.Y.Mc.l    J,,Ur 
Dec.  i:..  I'.iOU,  p.  l'J(H. 


1(1*14  MEDICAL    KLKCTKKTrY    AM)    KOVHiEN    RAYS 

RENAL    TUBERCULOSIS 

Tuberculosis  of  the  kidneys,  according  to  Brow.'  presents  radio- 
graphic  appearances  of  diagnostic  value.  Such  a  kidney  casts  a  well- 
marked  shadow.  In  one  of  Brown's  cases  the  .r-ray  showed  a  shadow 
suggestive  of  renal  calculus,  and  an  operation  showed  that  the  kidney 
was  tuberculous  anil  filled  with  a  putty-like  substance.  .1.  Bayard 
Clark"  and  others  have  reported  cases  of  tuberculosis  of  the  kidney 
which  were  diagnosed  by  radiography,  combined  with  cystoscopy  and 
crvoscopy. 

A  radiograph  of  urine  in  a  case  examined  for  Dr.  K.  L.  Keyes,  Jr., 
gave  positive  indications  of  the  character  of  the  lesion. 

RADIOGRAPHY  OF  VESICAL  CALCULUS 

Two  positions  are  available.  One  is  with  the  patient  face  down 
upon  the  plate  and  the  tube  in  the  median  line  at  a  lower  position,  so 
that  the  rays  will  shine  obliquely  upward  through  the  pelvis  and  pre- 
vent the  shadow  of  the  sacrum  from  filling  up  the  entire  image  of  the 
pelvic  canal.  In  the  other  position,  the  patient  lies  face  up  upon  the 
plate,  and  the  x-ray  tube  is  in  the  median  line,  about  3  inches  above 
the  symphysis  pubis,  the  anticathode  being  at  a  distance  of  17  inches 
from  the  plate  if  no  cylinder  diaphragm  is  used,  and  about  24  inches 
if  this  apparatus  is  used. 

The  rays  traverse  the  pelvis  in  the  same  line  in  both  cases,  but  in 
opposite  directions.  The  idea  is  to  show  the  cavity  of  the  pelvis  as 
free  as  possible  from  the  shadow  of  the  sacrum.  The  author  places  the 
plate  behind  and  the  tube  in  front,  but  some  others  prefer  the  ventral 
position,  on  the  theory  that  it  brings  the  plate  nearer  the  bladder  and 
consequently  nearer  the-  stone.  As  it  is  better  to  have  the  bladder 
empty,  and  as  the  stone  is  almost  always  near  the  neck  of  the  bladder, 
this  reasoning  does  not  seem  exactly  correct. 

The  author's  cellular  diaphragm  u'ives  clearness  of  definition  through 
this  thick  portion  of  the  body  with  a  gas-filled  tube  better  than  in  any 
i  it  her  way. 

The  exposure  should  be  the  same  as  for  the  kidney  (see  Exposure 
Table,  pain-  M»v. 

The  rectum  and  bladder  contents  should  be  evacuated,  and  a  much 
clearer  image  will  be  obtained  if  both  these  cavities  are  filled  with 
oxygen  gas, 

A  case  has  been  reported  in  which  the  radiograph,  made  in  the  ordi- 
.  did  not  show  a  small  stone,  which  was  clearly  depicted  on  a 
photographic  film  held  in  the  vagina,  just   as  radiographs  of  the  teeth 
;    •    "      ;•    upon  ;i  film  held  ii^ide  the  mouth. 

-on*  s,  shown  in  one  of  the  author's  cast's,  ]1;(,1  ]lot  been  discov- 

:  I'.ottini  operation  for  prostatic  hypertrophy  was  performed 

1  ".'O  :  reviously,  and   consequently  no  improvement    had  followed 

lion.      The  pat ient,  a  man  of  sixty-five,  was  sick  in  bed,  having 

irrigated   five  or  six  tunes  a  dav.  and  suffering  great  pain. 

to  discover  any  stone  two  weeks  before  t  he  x-ray  exami- 

'.':.       1  he  radiograph  showed  two  large  calculi,  \\luch  were  removed 

'      M    by    Dr.     I'.uck    Carleton.       He    found    that     the    stones 

•    .''       i!  •    consistence,  which  accounted  for  the  impossibility 

M>    :    ',.  :.!•,,-!  'nn:irv  Si-dicm.  Oct.    17.   1'.«>H:  X.    Y.   Mc-1.  .lour., 
[)•<•] 

1 1 i: 


THK    .r-HAY  1005 

of  detecting  them  by  ordinary  means  of  examination.  Since  the 
operation  the  old  gentleman  is  able  to  run  up  and  down  stairs  and  rode 
100  miles  on  horseback  in  one  day  a  year  later.  The  r-ray  has  actually 
saved  this  man's  life. 

Vesical  calculi  are  usually  made  up  of  oxalates  or  phosphates,  some- 
times having  a  nucleus  of  uric  acid,  and  are  usually  of  considerable  size. 

Moseley1  prefers  to  have  the  patient  lie  face  down  on  the  plate,  so  as 
to  bring  the  bladder  nearer  the  plate. 

The  bladder  and  rectum  should  be  empty. 

The  bladder  and  rectum  may  be  filled  with  oxygen  gas,  but  this  is 
not  entirely  free  from  danger,  and  Saenger  reports  a  fatal  case. 

An  encysted  calculus  in  the  lower  posterior  wall  of  the  bladder 
was  found  by  means  of  a  radiograph  by  .Menges,  and  removed  by  Holmes-'* 
after  systematic  exploration  with  a  searching  sound  under  general 
anesthesia  had  failed  to  discover  it.  It  was  completely  encapsulated. 

In  cases  examined  for  vesical  calculus  the  kidnevs  and  ureters  should 
also  be  radiographed.  Many  vesical  calculi  originate  in  the  kidney,  and 
it  18  wise  to  see  whether  new  ones  are  forming. 

Beck4  states  that  since  he  has  begun  to  radiograph  the  kidney  as 
well  as  the  bladder  he  has  found  renal  calculi  in  every  case  of  vesical 
calculus.  This  observation  makes  it  important  to  investigate  the 
kidney  regions  as  well  as  the  bladder.  Additional  observations  arc;  re- 
quired to  determine  whether  such  a  combination  is  invariably  present. 

PROSTATIC  CALCULI 

A  case  of  this  comparatively  rare  condition,  referred  by  Dr.  J. 
P.  McGowan,  was  readily  shown  by  a  radiograph.  The  patient  lay 
supine  upon  the  plate,  the  lower  end  of  which  was  raised  to  an  angle 
of  20  degrees  with  the  table1,  and  the  tube  was  4  inches  above  the  sym- 
physis pubis.  This  was  with  the  idea  of  securing  an  image  of  the 
calculus  not  overlapped  by  that  of  the  pubic  bones.  This  did  not 
prove  to  be  the  case,  but  the  calculus  was  such  an  enormous  one  that 
this  makes  little  difference.  In  fact,  in  this  picture  the  image  of  the 
stone  completely  overshadows  that  of  the  symphysis  pubis.  \Vhether 
the  object  could  be  obtained  by  placing  the  tube  at  a  considerably 
lower  level  than  the  symphysis  is  not  known  by  actual  experiment, 
but  it  seems  probable.  If  so,  the-  stone  would  cast  an  image  below 
the  arch  of  the  pubis,  but  overshadowed  by  the  image  of  the  sacrum 
and  coccyx. 

Considering  also  the1  possibility  that  the  calculus  might  be  in  the 
bladder  instead  of  in  the  prostate,  the  position  adopted  in  making  this 
radiograph  seems  the  most  desirable  one. 

Figure  744  is  a  radiograph  made  with  the  author's  radiating  dia- 
phragm of  this  calculus  after  removal,  and  Fiti.  71.1  is  an  ordinary  pho- 
tograph of  the  calculus  held  in  the  hand  and  with  a  scale  graduated  in 
inches  for  comparison. 

The  xiniintil  reticles  have  been  shown  in  radiographs  made  after 
injection  of  5  per  cent,  argyrol  solution." 


lOtili 


MKDU'AL    KLECTHIC1TY    AND    RONTGEN    RAYS 


Fiuf-  714   — Radiograph  of  prostatic  calculus 


izc).  Radiating     calculu.-  alter  removal  (scale  of  inches 


crllular  diaphragm  employed 


for   comparison  i.     (Case  examined  for 


FOREIGN    BODIES    IN   THE    PELVIC    ORGANS 

Foreign  bodies  in  the  bladder,  vagina  or  uterus,  or  the  rectum  are 
well  shown  in  a  radiograph  of  the  pelvis  made  with  the  plate  under  the 
patient  and  the  tube  over  the  median  line  \  inch  above  the  symphysis 
pubis. 

THE   PELVIC   BONES 

The  pelvis  is  well  shown  in  a  picture  made  as  for  vcsical  calculi; 
but  ior  the  sacrum  and  coccyx  especially  the  pelvis  is  tilted  forward, 
and  the  tube1  is  just  above  the  level  of  the  symphysis  pubis.  The 
compression  board  and  the  cellular  diaphragm  are  used  and  the  other 
conditions  are  the  same  as  for  renal  calculi. 

Non-union  of  the  Symphysis  Pubis. — This  condition  as  a  con- 
genital defect  was  found  in  a  case  of  epispadias  reported  by  Mouratoff.1 
The  radiograph  showed  that  there  was  an  absence  of  union  between 
the  pubic  bones,  and  that  the  symphysis  was  a  relaxed  membranous 
barrier. 

Separation  of  the  Symphysis  Pubis. — This  injury  is  not  so  very 
rare  as  a  complication  of  difficult  parturition  and  can  be  recognized 
ii.  ;i  radiograph. 

Radiography  of  the  Symphysis  Pubis  and  Its  Normal  Appear- 
ance.    The   radiograph   may   be  made  with    the   tube  in   the  median 
line,  ,-ind  about    1   inch  above  the  symphysis,  with  the  plate  under  the 
of   the   pelvic     The  distance  from   the  anticathode  to  the  plate 
iio'ild    be  ,-ib<iut    Jo   inches,    ">-iiich    resistance.  oO  ma.  for  ten  seconds 
an   inten-ifyiniL  or  any  other  MOO  ma.   second  exposure  for  an 
I  .")H-p(  iinif  |     man;     1-inch     back-up    and    same    exposure    with 
an    inti'i  .     -creen.      The    radiograph    U   likely    to    be  a    good    one 

Roii.-vkv  Vratch.,  .lulv  'JO.  1 '.«>•_>. 


THE    ar-UAY 

in  spite  of  the  fact  that  the  part  to  he  depicted  is  at  a  distance  from  the 
plate. 

Another  position  is  for  the  patient  to  lie  face  down  upon  the  plate, 
the  center  of  which  is  under  the  symphysis  puhis.  The  tuhe  is  in  the 
median  line  and  at  a  lower  position,  so  that  the  shadow  of  the  sacrum 
will  fall  at  a  higher  level  than  the  symphysis.  The  idea  is  to  have  tin- 
ray  pass  along  the  same  line  as  with  the  patient  in  the  dorsal  position, 
but  in  the  opposite  direction. 

Kven  in  a  patient  sixty-five  years  old  the  symphysis  shows  normally 
a  complete  line  of  separation,  and  it  may  happen  that  in  a  perfectly 
normal  person  of  any  age  the  radiograph  may  show  an  apparently 
considerable  separation.  The  knowledge  of  this  fact  will  enable  one 
to  guard  against  the  error  of  mistaking  a  normal  for  a  pathologic  con- 
dition in  the  symphysis. 

Fracture  or  Dislocation  of  the  Coccyx. — It  is  suggested  by  the 
author  that  a  clearer  radiograph  of  the  coccyx  and  lower  part  of  the 
sacrum  may  be  obtained  upon  a  photographic  film  held  inside  the 
vagina,  just  as  radiographs  of  the  teeth  are  made  upon  films  held  in- 
side the  mouth.  A  fracture  or  dislocation  of  the  coccyx  could  be  very 
easily  and  beautifully  shown  in  this  way  if  present,  while  a  mere  sprain 
would  not  present  bony  lesions  and  would  be  diagnosed  by  exclusion. 
The  rectum  should  be  empty. 

The  Lumbar  Vertebrae. — Examinations  of  the  lumbar  vertcbne 
for  fracture  or  tuberculosis  is  practicable  and  reliable  by  means  of  the 
technic  recommended  for  renal  calculi. 

Radiography  of  the  Fetus  in  Utero. — The  fetal  head  shows  well 
when  it  occupies  the  lowest  part  of  the  uterus,  to  the  practical  ex- 
clusion of  the  liquor  amnii,  but  when  the  head  occupies  the  fundus 
of  the  uterus  the  surrounding  fluid  produces  so  much  dispersion  as  to 
make  the  radiograph  unsatisfactory.  The  fetal  bones  arc  small  and 
almost  entirely  cartilaginous,  so  that  it  is  difficult  to  distinguish  them  in 
a  radiograph  before  birth. 

The  possibility  of  destroying  the  vitality  of  the  fetus,  or  of  pro- 
ducing sterility  through  action  upon  the  mother's  ovaries,  should 
deter  one  from  making  repeated  .r-ray  examinations  during  pregnancy. 

A'-ray  Diagnosis  of  Pregnancy  and  of  Extra-uterine  Gestation. 
— A  radiograph  of  the  pelvis  will  be  of  service  in  either  of  these  con- 
ditions. What  is  found  is  apt  to  be  a  silhouette  of  the  fetal  mass  rather 
than  a  picture  of  its  different  bones. 

Lichonstein1  describes  a  case  of  extra-uierine  pregnancy  with 
mummification  of  the  fetus.  The  diagnosis  was  made  by  means  of  a 
radiograph  taken  with  a  medium  soft  tube  without  a  diaphragm  and 
an  exposure  of  one  and  three-quarter  minutes.  The  maternal  pelvis 
showed  sharply,  but  the  lumbar  vertebra-  were  not  so  distinct.  Over 
the  right  rim  of  the  pelvis  two  fetal  extremities  were-  seen,  one  being  a 
part  of  the  thigh,  r.nd  the  other,  at  an  angle  with  this,  being  the  leg. 
The  ribs  showed  as  a  striped  area  on  the  other  side  of  the  mother's 
pelvis.  A  pelvis  presentation  was  diagnosed,  which  was  verified  by 
operation. 

Dermoid  Cyst. —This  condition  showed  very  well  in  a  case 
referred  to  the  author  by  Dr.  John  M.  Keyes. 

1  Miinrh.  Mol.  \Voch.,  vol.  vi,  s-24. 


ions 


MKIM<  AL    KLK(  THIC1TY     AM)     KOXTCKN    HAYS 


THE    HIP- JOINT 

Dislocation,  cither  congenital  or  acquired,  and  fractures  of  the  neck 
of  the  femur  are  well  shown  by  a  radiograph,  but  the  use  of  the  fluoro- 
scope  is  not  to  lie  recommended. 

For  a  radiograph  the  patient  may  lie  either  prone  or  supine,  the 
limbs  are  extended,  and  the  compression  band  is  used  (Fig.  740).  For 
a  picture  of  both  hips  he  lies  face  up,  with  the  plate  under  the  back  of 
the  pelvis:  the  anticathode  is  directly  over  the  median  line,  1*  inches 
above  the  symphy<is  pubis,  anticathode  23  inches  from  the  plate.  The 
latter  should  measure  14  x  17  inches,  and  be  placed  transversely  with 
it-  center  at  the  level  of  the  trochantcrs.  For  a  picture  of  only  one  hip 
the  plate  measures  1 1  x  14  inches,  and  is  placed  longitudinally  with  its 


,  Mi        Kadinm'aphv  (if  hip-jomt   with  a  rninpri-sMnn  liand  ;in<]  the  author's  plati 


may   lie   placed  ami  changed   1<T  -tcrcnscnpic  pictures  \vithou1 


•    •  ••  •    ;     MI-MI     iiaL'c  1M.~>(>(.     The  author'-  contact  diaphragm  should  lie  used  in  con- 


'•enter  1   inch  internal  to  the  trochanter.     The  atiticat  hode  of  the  .r-ray 

'  ilic  i-  vertically   o\'er  the  center  of  the  plate,  at  a  distance  of  12  o  inches 

!  n  >m    it.      Tin-   tube  -hoiild   have  a   heavy   target,   the  ;•'>()  ma.  (  'oolidu'e 

tni    tube  be'ui'i  excellent,  but  longer  expo-ure-  than  fifteen  seconds 

interruptecl    to    avo'nl    overheating.     The    exposure    for    an 

v    blO-poiuid   man   would   be  .l-mch   sj)ark,   Ml)   ma.   for    fourteen 

ond~,  or  any  other    Kill   ma.  second-   without    an   intensifying  screen; 

-a me  expo-ure  with  a  -creeu  and  1-inch  -park  fsee  Fxposure  Table. 

Any   iliaphramn   or  cylinder  will   ui\'e   increa-ed  definition 

!''r  one   hip  at    a    time,    especially   with    a  gas-filled   tube,   but    it    is  not 

the     ('oolidire     tube     except      pM->ibly     in     a     Very     stollt 


TIIK    .r-KAV  1009 

Tuberculosis  of  the  Hip.—  Tuberculosis  of  the  hip  is  often  shown 
by  the  radiograph  at  an  earlier  stage  than  by  any  other  means.  The 
head  of  the  femur  may  be  almost  transparent  and  a  portion  be  absorbed. 

Among  the  signs  of  tuberculosis  of  the  hip  seen  in  the  radiograph 
may  be  an  unnatural  transparency  of  the  head  of  the  femur  or  of 
the  acetabulum,  due  to  deminerali/at ion.  Absorption  of  the  articular 
cartilages  would  be  shown  by  an  unnaturally  close  apposition  between 
the  bony  surfaces.  Malposition  is  readily  discovered.  There  may  be 
abscess-cavities  or  sequestra,  the  acetabular  cavitv  mav  be  enlarged, 
or  the  head  and  sometimes  part  of  the  neck  of  the  femur  may  have  dis- 
appeared. 

Lovett  and  Brown1  report  the  results  of  radiographic  study  in  100 
cases  of  suspected  hip  disease.  They  examined  the  collection  of  radio- 
graphs which  had  been  taken  at  their  hospital  for  a  number  of  years 
and  recorded  the  results  before  consulting  the  clinical  historic.-.  The 
radiographic  diagnosis  was  found  to  agree  with  the  clinical  diagnoHs 
in  all  but  o  of  the  cases.  The  cause  of  error  in  1  case  was  the  presence 
of  an  inguinal  abscess,  blurring  the  outline  of  the  head  and  neck  of 
the  femur  in  such  a  way  as  to  cause  it  to  be  mistaken  for  tuberculosis. 
Two  cases  with  normal  radiographic  appearances  proved  to  have  had 
hip  disease:  one  for  six  months  and  the  other  for  a  year.  All  the  other 
1s*  cases,  which  gave  a  normal  radiographic  appearance,  were  also  diag- 
nosed clinically.  Some  of  these  hips  showed  merely  incidentally  upon 
plates  made  for  stone1  in  the  bladder  or  other  troubles. 

Sixty-one  castes  were  diagnosed  from  the  radiographs  as  typic  hip 
disease,  and  this  was  confirmed  by  the  clinical  histories,  both  before  ami 
subsequent  to  the  making  of  the  radiograph. 

Tin4  radiographic  appearances  m  an  early  stage,  when  the  only 
symptoms  are  sensitiveness  and  muscular  spasm,  may  not  be  percept- 
ibly different  from  those  of  a  normal  hip. 

When  limitation  of  motion  due  to  spasm  occurred  the  radiographs 
showed  evidences  of  bony  atrophy.  The  earliest  evidences  of  atrophy 
are  diminished  density  and  size  of  the  bonv  shadow. 

Bony  thickening  is  a  reparative  process,  and  is  sometimes  seen  at  a 
later  stage. 

"Reduced  radiability  "  is  the  name  given  by  Lovett  and  Brown 
to  a  condition  in  which  the  radiographic  image  is  blurred  or  obscured; 
not  merely  faint  from  lack  of  density  in  the  bones  depicted.  This 
condition  may  be  due  to  the  presence  of  thick  serum,  pus,  or  detritus 
in  the  joint.  Similar  material  outside  of  the  joint  will  produce  the  same 
radiographic  effect,  and  Lovett  and  Brown  found  it  deceptive  in  a  case 
of  inguinal  abscess. 

Krosion  or  actual  loss  of  bone  substance  was  present  in  some  cases, 
and  was  always  shown  by  the  radiograph.  It  varied  from  simple 
irregularity  of  the  articular  surface  to  caviiies  or  complete  absorption. 

Dixplficcwcnts  Resulting  from  Hi/>  !)i*«it«'. — These  are  grouped  by 
Ashley'-'  in  three  classes,  and  he  states  that  a  good  radiograph  affords 
the  only  means  of  positively  distinguishing  between  these. 

In  group  A  the  proximal  end  of  the  femur  rests  well  within  the 
acetabulum.  In  group  B  the  proximal  end  of  the  femur  rests  near  or 
upon  the  rim  of  the  acetabulum.  In  group  ('  the  proximal  end  of  the 
femur  lies  1  inch  or  more  from  the  acetabulum. 


1070 


MKDICAL    KLKCTKKITY    AND    KONTCEN    HAYS 


Mc< '  nrt/i/'.^  Trattx/t- trie  Line  for  Determining  Displacement  at  the 
Hip. — This  line  may  he  applied  to  radiographs.  A  line  through  the 
spines  of  the  pubic  hones  passes  outward  across  the  normal  position  of 
tlie  hip-joints  and  the  top  of  the  great  trochanter.  Displacement  may 
lie  above  or  below  this  line.  Lateral  displacement  is  measured  from  a 
line  drawn  perpendicular  to  the  transpelvic  line  and  passing  through 
the  anterior  superio"  spine  of  the  ilium. 

Figure  717  >ho\vs  the  tip  of  the  great  trochanter  at  the  level  of  the 
top  of  the  head  of  the  femur,  and  considerably  above  AlcCurdy's  trans- 


[i:c..nt!i~    uM   t'racture  of  neck   »\    femur  uitli    non-union.      (Patient  re* 


pelvic  line,  wliile  the  head  of  the  femur  is  crossed  by  this  line.     These 
!<•'-   would  establish  ;i   fracture  of  the  neck  of  the  femur  even  ii   the 
:  >!'<••;  k  in  i  he  bone  were  not   visil  >le. 

Fracture  of  the  Acetabulum.  The  examination  for  this  injury  is 
the  *ame  M-  foi'  ili-location  of  the  hip.  The  head  of  the  femur  may  be 
nearer  :he  median  line  than  noi'tnally.  and  may  obscure  the  image'  of  the 
p<  hi-  ;ii  MM-  point.  The  inner  surface  ot  the  pelvis  here  may  show 
I  in  >t  ru-i'  >n  or  -phrit  cnng. 

AIIKT    .lour.  <»rtliop.  Suriiery.   I'.ill.'i. 


THE    .r-KAY  1071 

Gourdon1  published  radiographs  showing  anatomic  changes  \vhicli 
take  place  after  bloodless  reduction  of  congenital  dislocation  at  the  hip. 

Fracture  of  the  Anterior  Superior  Spine  of  the  Ilium  by  Mus- 
cular Action.—  This  condition  \vas  demonstrated  in  a  case  reported 
by  Hebee.-  Part  of  the  pelvis  may  be  shown  in  a  radiograph  made 
with  the  plate  upon  the  table,  and  the  patient  lying  face  up.  but  with 
the  pelvis  turned  a  little  toward  the  affected  side.  The  lube  should 
be  over  the  median  line  ot  the  abdomen.  2  inches  above  the  svmph\>is 
pubis.  The  anticathode  should  be  at  a  distance  of  1(1  or  IS  inches 
from  the  plate.  A  suitable  exposure  for  an  ordinary  InO-pound  man 
would  be  4-inch  spark,  intensifying  screen.  KM)  ma.  seconds. 

Congenital  Dislocation  of  the  Hip.  The  .r-ray  diagnosis  is  based 
upon  a  radiograph,  made  with  the  patient  lying  upon  his  back  with 
The  plate  underneath  and  the  .r-ray  tube  vertically  over  a  point  in  the 
median  line  and  1  inch  above  the  symphysis  pubis.  The  anticathode 
should  be  at  a  distance  of  2o  inches  from  the  plate  for  a  small  child  or 
for  an  adult. 

A  case  had  been  sent  to  Dr.  Kerley  as  one  of  infantile  paralysis  but. 
suspecting  congenital  dislocation  of  the  hip.  the  doctor  had  sent  the 
case  to  the  author  for  a  radiograph.  On  the  sound  side  the  head  of 
the  femur,  still  a  separate  epiphy.-is.  as  the  child  was  only  three  or 
four  years  old.  was  seen  in  close  contact  with  the  acetabulum,  while  on 
the  affected  side  there  was  a  distance  of  fully  ',!  inch  between  the  ace- 
Tabulum  and  the  head  of  the  femur.  The  latter  rested  upon  the  ilium 
above  the  acetabulum.  A  glance  at  the  rluoroscopic  image  did  not 
show  the  dislocation,  but  the  radiograph  did  so  at  once.  The  left  hip 
was  seen  to  be  normal,  with  the  head  of  the  femur  in  contact  with  the 
acetabulum,  while  \\u  head  of  the  right  hip  was  about  1  inch  away 
from  the  acetabulum  and  rested  upon  the  ala  of  the  ilium. 

Stereoscopic    Rcifliogrdphx   <>J    Contjcnitdl    Ijixlocdtion    »J   (hi     HI/>. — 
These  picture.-,  as  pointed  out  by  Ilildebrand/'  are  Useful  as  a  mean-  of 
showing  the  direction  and  extent  of  displacement  in  a  sagittal  or  antero- 
po-terior  plane.     Ordinary  radiography  would  not   -how  this  di-place- 
ment.  but  only  lateral  or  vertical  displacement. 

A  Case  of  Old  Ununited  Fracture  of  the  Neck  of  the  Femur.- 
The  radiograph  i  Fig-.  717'  was  made  seven  months  after  injury,  during 
which  time  the  patient  had  been  walkinu'  around  with  a  crutch. 

THE    THIGH 

Fluoroscopic  examination  -niceeeds  well  in  determining  fracture, 
sarcoma,  exostosis  or  necrosis  of  the  femur,  and  in  locating  foreign 
bodies.  The  tube  for  such  a  fluorosropic  examination  should  have  a 
vacuum  represented  by  a  fi-inch  resistance,  the  secondary  current  should 
be  ;"i  milliamperes.  and  care  should  be  taken  not  to  expose  the  patient 
to  the  .r-ray  more  than  two  or  three  minutes  with  the  anticathode  at  a 
distance  of  10  inches  from  the  nearest  surface.  The  tube  may  be 
placed  further  awav  and  several  btief  exposures  made  to  cover  the 
whole  operation-  removal  of  a  foreign  body  or  dressing  a  tracture. 
For  the  latter  purpose  it  i-  very  convenient  to  have  the  .r-ray  tube  under 
the  wooden  table  on  which  the  patient  lies. 


MKDICAI.    KI.KCTKiriTY    AM)    KOXTiiKX     HAYS 

In  making  a  radiograph  of  the  thigh  cither  a  lateral  or  an  antero- 
posterior  view  may  he  shown.  For  the  latter,  the  patient  lies  on  his 
hack,  witli  an  llxll  inch  plate  under  the  thigh,  the  antieathode  di- 
rectly over  the  middle  of  the  thigh  and  the  middle  of  the  plate,  and 
'2'.\  inches  from  the  latter.  The  exposure1  for  an  ordinary  150-pound  man 
would  he  4-inch  spark.  oO  ma.,  twelve  seconds,  or  any  other  300  ma. 
exposure,  no  intensifying  screen.  A  radiograph  made  by  the 
at  St.  Bartholomew's  Clinic  showed  a  bullet  flattened  out  on  the 
This  \vas  removed  after  twelve  days  by  means  of  the  rluoro- 
a  radiograph  he  ing  taken  just  after  the1  bullet  had  been  seized 
forceps.  Attempts  at  another  hospital  to  locate  the  ballot  by 
probing  had  failed.  The  reason  was  that  the  bullet  had  glanced  along 
the  femur  to  a  place  where  it  was  covered  by  dense  fascia. 

For  a  lateral  view  of  the  thigh  the  plate  may  bo  applied  most  con- 
venicnilv  to  the  inner  side  of  the  thigh,  the  patient  lying  on  his  side 
with  the  plate  pressed  between  the  two  limbs.  The  author's  lateral 
plate-holder  enables  the  patient  to  lie  face  up  with  the  plate  held  at 
either  the  outer  or  the  inner  side  of  the  thigh. 

The  Author's  Lateral  Plate-holder  in  Radiography  of  the 
Thigh. — This  is  especially  useful  because  it  affords  an  opportunity 
to  make  a  preliminary  fluoroscopic  examination  with  a  view  to  placing 
the  limb  in  the  best  position.  For  this  purpose  the  patient  may  sit  up 
on  the  operating  table,  with  the  affected  limb  resting  on  the  horizontal 
le'<:-pioce.  while  the  other  limb  extends  vertically  downward,  or  the 
patient  may  -land  beside  any  ordinary  table,  with  the  sound  foot 
ivMilm'  on  the  ground  and  the  affected  thigh  resting  on  the  table. 
The  tube  is  at  the  side,  a\vay  from  the  table,  and  the  plate  is  held  in  a 
vertical  position  at  the  other  side  of  the  thigh.  It  does  not  matter 
whether  this  is  the  inside  or  the  outside  of  the  limb.  A  glance  with  the 
iluoroscope  while  the  limb  is  rotated  in  different  directions  would  reveal 
the  lesion,  and  show  the  best  position  in  which  to  make  the  radiograph. 
The  case  referred  to  above  was  one  of  oblique  fracture  of  the  femur 
without  complete  solution  of  continuity,  but  with  a  sharp  projecting 
sliver  of  bone  which  irritated  the  soft  tissues.  There  was  also  a  fracture 
of  the  neck  of  the  femur. 

A  preliminary  Macroscopic  examination  will  also  enable  us  to  avoid 
the  error  in  the  diagnosis  of  a  fracture  into  which  a  single1  radiograph 
niiulii  lead  us  if  it  chanced  that  the  rays  passed  in  the  same  plane  as 
that  in  which  the  fragments  we're  bent.  The  hone  would  appear 
perfectly  straight  in  this  position,  whereas,  seen  from  any  other  direc- 
tion, it  would  show  deformity.  To  represent  the  condition  truly  the 
.r-ray  ,-hould  .-him1  through  the  thigh  at  a  right  angle  to  the  plane  in 
which  the  two  fragments  lie.  It  is  better  to  secure  this  position  by 
adjust  ni' 'lit  under  t  he  guidance  of  the  II  Horoscope,  and  then  to  take  one 
correct  radiograph,  than  to  depend  even  upon  two  radiographs — 
an'  eroi  iost  erior  and  lateral. 

The  upper  part  of  the  femur  requires  the  same  intensity  and  quality 
of  radiance  and  the  same  length  of  exposure1  as  the  hip-joint,  while  the 
lower  part  of  the  thi-Ji  affords  a  better  picture1  in  half  the  time. 

RADIOSCOPY   OF   THE   KNEE 

The  knee  may  he  .-tudied  with  the  fluoroscope,  and  fracture1  of  the 
patell.-i  Hi'  liMtiv  changes  1mm  tubercular  arthritis  recognized.  A  lateral 


107:5 

view  is  the  most  useful  one.  Still  it  must  he  rememhered  that  it  is  a 
thick  dense  portion  and  that  the  illumination  required  is  powerful, 
and  consequently  no  prolonged  examination  should  he  made.  The 
radiograph  of  the  knee  is  usually  taken  in  the  lateral  direction,  and  if 
the  plate  is  at  the  inner  side  the  internal  condyle  will  show  most  'clearly, 
the  external  condyle  appearing  larger  and  less  distinct.  Placing  tin- 
plate  at  the  outside  will  <iive  a  hetter  picture  of  the  external  condyle. 


The  nntieathodo  -hoiild  he  at  a  di-tance  of  '2'-\  indie-  vertically  ahove 
the  ciMitei'  of  the  plate,  and  this  point  -hould  correspond  to  a  point  just 
|)i  interior  to  the  plane  of  the  patella  and  just  helow  the  lower  end  of  the 
condyles.  In  thi-  way  the  imasi'e  of  the  patella  -how-  separately  and 
so  do  those  of  the  femur  and  tihia.  The  .r-rav  -hould  pa--  through  the 
knee-joint  at  the  level  of  contact  hetween  the  artictilar  -urface-  ot  the 
condyle-  and  the  tihia.  Thi-  level  i-  most  readily  found  hy  tlexinu'  the 
tis 


1074 


MKDICAL    KLKCTKiriTY    AND    HONTCEX    HAYS 


knee.  In  this  position  the  patella  and  the  condvles  form  the  lower 
end  of  the  straight  line  of  the  thigh.  Having  determined  this  level 
the  knee-joint  may  be  straightened.  The  fibula  shows  well  in  a  radio- 
graph taken  with  the  plate  at  the  outside.  The  exposure  should  he  six 
second^  with  :>0  ma.,  4-inch  resistance,  or  any  other  ISO  ma.  second  ex- 
posure for  an  ordinary  150-pound  man. 

Oxygen  Injections  into  the  Knee-joint  for  Radiography. — Distend- 
ing the  knee-joint  with  oxygen  or  any  other  gas  improves  the  radio- 
graph in  two  ways— the  bony  details  are  brought  out  almost  as  clearly 
as  if  it  were  a  skeleton  knee;  the  soft  parts  also  may  be  differentiated  to 
an  extent  impossible  under  ordinary  conditions.  Holla1  has  published 
such  radiographs. 

Hoffa's  method  is  to  have  the  oxy- 
gen gas  generated  in  a  tank  of  hydro- 
gen peroxid  to  which  tablets  of  potas- 
sium permanganate  are  added.  An 
aseptic  injection  of  oxygen  was  at  first 
thought  to  be  harmless  and  even  bene- 
ficial in  certain  cases  (Fig.  749). 

Danycr  of  Oxi/t/en  Injection  info 
Joints. — Jacobsoir  reports  a  fatal  case 
which  was  attributed  to  nervous  shock. 
Holzknccht  has  had  a  similar  expe- 
rience. In  Hoffa's  clinic  pains  are 
taken  to  see  that  the  oxygen  is  chemi- 
cally pure',  and  t  hat  t  he  inject  ion  ceases 
the  moment  t  he  synovial  cavity  is  full. 
Schwartz  considers  an  Ksmarch  band- 
age a  necessary  precaution  against  the 
gas  entering  a.  vein. 

Radiography  of  the  Patella.-  The 
author's  screen  for  soft  rays  comes  into 
play  in  making  a  radiograph  of  the 
patella  with  the  plate  in  front,  directly 
in  contact  with  the  patella,  and  the 
tube  close  behind  the  knee.  We  se- 
cure in  1  his  way  a  pict  lire  of  t  he  patella 
as  it-  would  appear  if  laid  bare  and 

at  from  in  front.  Such  a  picture  would  be  of  value  in  cases  of 
•  of  the  patella.  As  explained  on  p.  9(Ki,  the  screen  for  soft  rays 
enables  the  lube  to  be  -afely  placed  so  near  the  hack  of  the  knee  that 
the  linage  o|  the  portions  at  a  greater  distance  from  the  plate  is  so  en- 
larged ;iiid  indi-t  inct  as  to  form  merely  a  background  for  the  clearer 
linage  of  the  patella.  The  author's  contact  diaphragm  gives  a  still 


•CtHlf! 


in-r  radiograph  of  the  patella  in  this  position. 
Fracture  of  the  Patella.     According   to    l!a 
.r-rav    rev 
LMIO-is 


holt  s    experiments1' 

Mlbpcriosteal  fracture-  of  the  patella  which  would 
my  other  way.  Such  a  fracture,  without  rupture  of 
•ion  of  the  (piadriceps  tendon,  is  usually  caused  by 

li  ,  July  <;,  t'.ior,. 
t-'\.,  April  10,  I '.M 17.  p.  L'C.O. 
\--nr..  vol.  xlvii,  NIL  !.">,  Oct.  IM,  I1.  Hdl,  ]..  1177. 


THE    .T-HAY  1075 

direct  violence,  and  starts  from  within  the  bone  and  is  widest  at  the 
articular  surface.  This  type  of  fracture  is  one  in  which  bony  union 
may  be  expected  without  operative  treatment. 

Barlocher1  reports  the  x-ray  demonstration  of  bony  union  in  the 
patella  in  cases  operated  upon  as  follows:  A  median  incision  is  made 
and  the  blood  clots  cleaned  out,  the  tear  in  the  capsule  is  closed  by 
sutures  at  each  side  of  the  patella,  and  a  row  of  sutures  is  taken,  which 
include  the  periosteum  and  posterior-  wall  of  the  prepatellar  bursa. 

.•1  (Vf.sr  of  lioini  Cnion  .\fttr  fracture  of  (he  Patella. — The  patient, 
a  distinguished  surgeon,  sustained  a  fracture  of  the  patella  from  direct 
violence,  falling  and  striking  his  knee  on  the  stone  {lavement,  twelve 
years  before  a  radiograph  was  made.  The  .r-ray  examination  was 
made  because  of  pain  in  the  knee,  but  the  picture  revealed  no  abnor- 
mality except  a  small  area  of  ossification  in  the  quadriceps  extensor 
tendon  close  to  its  attachment  to  the  patella. 

Dislocation  of  the  Patella.— This  condition  of  lateral  displacement 
of  the  patella  may  be  shown  in  a  lateral  radiograph  made  with  the  knee 
flexed  or  in  a  radiograph  made  with  the  plate  in  front  and  the  tube 
behind.  In  the  lateral  view  the  patella  is  seen  overlapping  the  image 
of  the  condyles  instead  of  projecting  in  front  of  them.  The  antero- 
posterior  radiograph  will  also  show  the  displacement  better  in  a  posi- 
tion of  flexion.  Chevrier2  publishes  radiographs  of  this  condition. 

Radiography  of  Germ  Valgum  or  Knock-knee. — The  deformity 
is  .-hown  to  consist  in  an  inward  convexity,  usually  of  the  upper  end 
of  the  tibia,  sometimes  of  the  lower  end  of  the  femur,  and  occasionally 
of  both.  The  deformity  is  seldom,  if  ever,  at  the  knee-joint.  Hof'fmair 
finds  the  radiograph  of  value  in  determining  the  location  of  the  curva- 
ture and  the  correct  place  to  exert  pressure  by  a  brace.  The  latter 
should  press  on  the  abnormal  curve  aiid  not  on  the  knee. 

RADIOGRAPHY  OF  BOW-LEGS 

This  shows  that  the  deformity  is  due  to  curvature,  either  of  the 
tibia  or  femur  or  both,  and  not  to  bending  at  the  knee.  Fig.  ~*'l,  p. 
1114,  shows  just  where  pressure  by  a  brace  should  be  applied.  The 
radiograph  would  show  where  to  perform  an  osteotomy  in  an  older 
child  for  whom  the  brace  would  not  do  any  good. 

RADIOSCOPY  OF  THE   LEG 

The  leg  could  lie  examined  with  the  Huoroseope  except  for  the  danger, 
and  fractures,  tumors,  and  foreign  bodies  are  the  principal  conditions 
studied.  A  convenient  position  is  the  patient  standing  with  the  foot 
resting  upon  a  chair,  the  .r-ray  tube  being  at  the  inner  side  of  the  leg  and 
a  little  behind  it.  This  enables  one  to  see  the  tibia  and  fibula  without 
overlapping.  The  same  position  can  be  u>ed  for  radiography,  in  which 
case  except  for  the  danger  we  would  take  a  glance  with  the  fhloroscope 
to  make  sure  that  the  shadows  of  the  two  bones  show  separately,  and 
then  hold  the  plate  in  position  at  the  outside  and  a  little  in  front  of  the 
leg.  A  possible  disadvantage  is  that  the  patient  may  not  keep  perfectly 
still.  Another  method  consists  in  having  the  patient  lie  down  on  a  table, 

.  to.  I'.to:!. 

\ssoc.,    Au'Mi-t    Hi.    100t>;  Jour.   Am.   Moth 


\jjsoc.,  >i'pt .  S.  1  <)()<)   p.  SO  1 


KM)  MKD1CAL    KLKCTRICITY    AND    ROXTGKN    RAYS 

with  tluj  le.tr  resting  upon  the  plate,  and  taking  one  picture  almost 
directlv  anteroposteriorly,  but  with  the  le«r  rotated  inward  a  little,  and 
.mother  picture  almost  directly  from  the  side.  In  the  last  case  either 
side  of  the  letr  and  foot  may  rest  upon  the  plate.  Distance1  from  anti- 
cathode  to  plate1  23  inches,  exposure  six  seconds  with  30  ma.  or  any 


other   'HI   ma.    >econd   e\po.-ure   for  an   ordinary    150-pound   man.     No 
mt  en  ~if  \  mi:  -rrei-n. 

Tin-  author's  lateral  plate-holder  make-  it  verv  easy  to  secure  the 
corri'd  pn-ition,  with  the  tibia  and  fibula  showing  separate  shadows. 
Th''  ktici'  anil  aiikh'  arc  supporteil  on  books,  leaving  the  portion  of  the 
I'-jr  to  be  radiographed  entirely  free. 


There  are  cases,  however,  in  which  t  he  deformity  or  ot  her  lesion  is  not 
correctly  shown  from  this  direction--/,  e.,  with  the  ray  pa-.-inn  through 
the  interosseous  space  and  the  plate  either  in  front  or  behind,  and  in 
which  the  idea  of  securing  separate  shadows  ot  the  two  bone-  ha.-  to  be 
abandoned.  Kven  then,  if  the  plate  is  external  and  the  expo-ure  rather 
strong,  the  outline  ot  the  filmla  mav  l>e  seen  on  the  background  of  the 
tibia.  The  n  ppe  rand  lower  parts  ,  if  t  he  filmla  are  easily  .-how  n  in  1  his  wav. 

A  Case  of  Simple  Fracture  of  Tibia  and  Fibula  United  With  Slight 
Malposition. — The  radiograph  i  Fi<i.  7  .">())  was  taken  as  proof  of  the 


nature  of  the  injury  in  a  suit  agam-l  the  company  responsible  tor  the 
accident,  and  not  on  account  of  any  complaint  airain.-t  the  surgeon  who 
treated  the  case.  A  radiograph  trom  another  direction  showed  marked 
anirular  '  left  irmity. 

A  Case  of  Simple  Fracture  of  Tibia  and  Fibula  After  Union  in  Mal- 
position. The  fracture  had  been  a  comminuted  one.  and  the  surgeon 
who  dre.--ed  the  injury  had  made  an  incision  and  removed  trau'ineni-  ot 
bone  and  placed  the  end-  in  u'ood  apposition.  The  bones  must  have 
Clipped  at  some  -ubseqiient  dre— ini:.  for  the  radiograph  Kiu.  7">1  . 
taken  -i\  month-  later,  .-hows  marked  lateral  displacement  ot  the  (Yai:- 


KITS 


MEDICAL    KLKCTKHITY    AND    RONTGEN    HAYS 


ments  df  both  hones  and  sonic  overriding  and  shortening.     The  picture 
shows  what  can  he  done  with  a  high-frequency  outfit. 

Pott's  Fracture. — This  fracture  of  the  fibula  1  or  2  inches  above  its 
lower  ext remit v  is  frequently  accompanied  by  a  fracture  of  the  internal 
malleolus  of  the  tibia  and  sometimes  by  laceration  of  the  internal  lateral 
deformity  is  produced  by  a  bending  directly  to  the 
ic  correct  radiograph  is  one  made  in  an  anteroposterior 
tube  should  lie  in  front  and  1  inch  above  the  level  of 
The  foot  is  fully  extended,  so  as  to  avoid  contact 
The  plate  is  placed  behind  the  ankle  and  heel.  The 
as  it  means  that  the  plate  is  1  inch  further  from  the 
ilate  were  held  close  to  the  back  of  the  ankle  above 


ligament.     Tin 

outer  side  and 
direction.     Tin 
the   ankle-joint. 
with  the  tube, 
heel  is  in  the  wa\ 
fibula  than   if  t  he 


the  heel.  The  latter  position  would  enable  us  to  show  a  fracture  a  couple 
of  inches  above  the  malleohis,  but  not  the  lowest  part  of  the  tibia,  which 
it  is  also  import  ant  to  show. 

The   author's   lateral    plate-holder   is   of   great    service;   here.     The 
patient  lies  on  the  operating  table,  with  the  foot  extended  and  its  inner 


-urface  n-stinir  on  a  book.      The  vertical  part  of  the  lateral  plate-holder 

.   7.VJ     hold-   the   plate  behind  the  foot,  and   the  tube  is  placed   in 

uid  at   a  di-tance  of  '2'.'>  inches  from  the  ant  icat  hode  to  the  plate. 

A  pn-liminary  fluoro-copic  examination  is  facilitated  bv  the  use  of  this 

I  i^.    ~ '>'•'>  .    bul     is    extremely    daimerou-    to    the    operator. 

;  -park,  Mi)  ma.,  and  no  intensifying  screen  t  he  exposure  for  a 

l.)0-pound  man  would    be   seven   and  a   half  seconds  or  any   other  2l2"> 

•xpo-urc  unless  the  ankle  were  in  plaster  of  1'aris.      In  the. 

latter  ca-e  an  intcn-ifving  -'Teen  would  be  used. 


TIIK    .C-RAY 


107(J 


>. — Fluoroscopv  of  the  ankle  preliminary  to  radiography  with  the  lateral 


holder.      An  extremely   dangerous   practice. 


1    : 


10SO 


MKIMCAL    Kl.F.i  TKKITY    AM)    KONTCKN     HAY 


FLUOROSCOPY   AND   RADIOGRAPHY   OF   THE   FOOT 

Fluoroscopy   <if   the   foot    is   useful    principally   in   the   diagnosis  of 
:':•:•.'•••;:•'••-  of  the  metatarsal  bones  and  the  phalanges,  and  in  the  location 
rif    foreign    bodies.      ()ther    conditions    in    the  foot    are  better    studied 
from  the  radiograph.      In  making  the  latter  tliei-e  are  several  different 
Thus,  for  the  toes  and  metatarsus  and  anterior  part  of  the 
.-.    the   Mile   of   the   foot    rests  upon   the   plate   with   the   ankle  fully 
led,    -o    that    the    ]CLT    is    drawn    well    back.      The    anticathode    is 
v  over  the  middle  of  the  foot,  at  a  distance  of  2'.*>  inches  from 
!'<>'•   the   ankle-joint    and   the   articulation   between   the  as- 
I  tin    ''-  faicis  the  foot    is  turned  .-o  that    the  inner  margin 
of   th'-   snle   rest    upon    the  plate,   and   a   compression  cylinder 
LI.  7-V>  .      |-'<>r  diairno-i-  of  flat-foot   the  inner  side  of  the  foot 
and  aii         fe-i    upon  the  plate.  m  a-  nearly  a   natural  position  as  possi- 
ble     :  '•       tube  vertically  over  the  prominent    ba.-e  of  the  fifth 
n  i  '••.•!'•  i '  - 

Hallux   Valgus.      I  i---.   7">7   7f'.D   illu-trate    a    case    of    hallux    \'al^u- 
operate.l    .  tin    author  at  M.  l>artholoinew'~  ( 'linic  and  reported 


THK    .r-HAY 


10SL 


in  the  New  York  Medical  Journal.  The  patient,  a  young  man  of  twenty- 
three,  was  almost  crippled  by  the  exaggerated  deformity  of  both  feet, 
the  radiograph  showing  thai  the  great  toe  was  at  a  right  angle  to  the 
corresponding  metatarsal  bone.  The  operation  consisted  in  cutting  out 
a  wedge-shaped  section  of  the  head  of  the  metatarsal  bone.  This  enabled 
both  bones  to  be  brought  into  a  correct  line.  The  kodak  picture  -hows 


the  deformity,  which  looks  like  a  swelling  or  bunion  on  the  great  toe- 
joint,  but  the  .r-ray  at  once  revealed  the  bony  deformity.  As  a  result 
of  the  operation  he  is  now  able  to  be  on  his  feet  eighteen  hours  a  day 
smashing  baggage  at  the  (Irand  Central  Station. 

Various  Anomalies  in   the   Tarsus.-    These   have   been   studied   in 
anatomic  specimens  and  in  radiographs  from  living  subjects.' 


1082 


MKIMCAL    ELECTRICITY    AM)    HONTdKN    HAYS 


The  .r-ray  is  valuable  in  cases  of  deformity  of  the  foot  as  a  guide 
to  operative  treatment  or  to  the  application  of  the  proper  means  of 
support. 

A  case  of  tali pcx  c(jitinu.s  was  radiographed  with  the  side  of  the  foot 
resting  upon  a  plate  placed  horizontally  on  the  table  upon  which  the 


(.1,11,1  lay.      The  tube   was  vertically  over  the  opposite  side  of  the  foot. 
Mv  rad'ioLrr:iph  -howrd  that  the  lonji  bones  of  the  foot  were  almost  in  a 

straight    line  with  those  of  the  le«r. 


THK    J-KAY 


1083 


I 


I 


I'lir.  7.~>S. —  Hallux  valf^us  after  operation  on  one  foot. 


iu.  7 .V.I.  —Hallux  vakus  after  operation  on  hotll  feet 


A  case  was  examined  for  possible  fracture  of  some  hone  in  the  tarsus. 
The  foot  was  deformed  in  consequence  of  infantile  paralysis  producing 


10S4 


MEDICAL    ELECTRICITY    AM)    RONTGEN    KAYS 


taji})<*  i<minn*.     When  the  man  was  barefooted  he  was  almost  a  cripple, 
but  when  he  wore  a  specially  constructed  shoe  he  was  able  even  to  take 


part    in  athletic   contests.     It   was  at   such  a   pastime  that  the  injury 
\vas   received  which   necessitated  an  x-rav  examination.     No  fracture 


ne-   i  taken  \vitli  Bn.w  h'.-  liiu)i-frec|uencv  apparatus, 


was   found.  itienl    had  designed  a  nio-t    -ervu-eable  -hoe.  \vhii 


lid   iml  ind   .in   the  outside.       1  here   \va-  a   pad  in>lde  under 


THK    J-KAY 


1085 


(he  heel  and  tarsus  and  under  the  outer  side  of  the  metatarsus,  while 
the  inner  side  ot  the  metatarsus  was  allowed  to  come  down  into  contact 
with  the  sole  of  the  shoe.  The  radiograph  showed  that  the  inner  meta- 
tarsals  were  strongly  flexed,  while  the  outer  ones  were  not,  and  the  os 
calcis  did  not  nearly  reach  the  ground. 

Benoist  's  radiochroniometer 
was  laid  upon  one  corner  of  the 
plate  to  register  the  decree  of 
penetration  of  the  ,r-rav.  This 
proved  to  lie  Xo.  S  Benoist  and 
seemed  to  he  excellent . 

Fracture  of  the  Tarsal 
Bones.-  This  condition  is  best 
shown  in  a  radiograph  taken 
with  the  plate  against  the  inner 
side  of  the  foot,  which  is  to  l;e 
inverted,  with  the  tube  at  the 
outer  side.  The  use  of  the 
author's  lateral  plate-holder  en- 
ables one  to  make  a  preliminary 
fluoroscopic  examination  and  place  the  tube  in  such  a  position  that  the 
ray  will  shine  through  between  the  bones  and  show  their  images  sepa- 
rately. The  toes  are  pointed  upward  and  the  heel  should  rest  on  a  book. 
The  photographic  plate  is  placed  vertically  beside  the  foot. 

Fracture  of  the  Metatarsal  Bones. — This  injury  often  presents 
the  same  difficulty  as  a  similar  injury  in  the  hand;  due  to  the  fact  that 
the  displacement  is  apt  to  be  in  a  dorsoplantar  plane,  the  one  usually 
traversed  bv  the  .r-rav. 


jz.  7<i2. — Fracture   of  a  phalanx 


A  Case  of  Fracture  of  a  Phalanx  of  a  Toe.—  The  younu  lady,  whose 
toe  is  -lioun  in  lig.  71)12.  caught  her  foot  in  her  dress,  and  as  she  stum- 
bled >t  ruck  her  loot  violently  airain.M  the  door-post.  She  was  in  her 
stockinged  feet  and  all  1  he  force  was  received  by  the  little  toe. 

Congenital  Absence  of  Last  Phalanx  of  Great  Toe.-  Figure  7(iM 
illu-t  rates  t  his  condit  ion. 


1080 


MEDICAL    KLKCTRICITY    AND    RONTGEN    RAYS 


THE  UPPER  EXTREMITY 

In  a  small  or  medium-sized  person  a  fluoroscopic  examination  suc- 
ceeds fairly  well  about  the  shoulder,  l-'ractures  of  the  humerus  and 
dislocations  at  the  shoulder-joint  show  very  well.  Fractures  of  the, 
scapula  and  clavicle  arc  more  difficult  with  the  fluoroscope,  and  so  are 
the  different  diseases  of  the  shoulder-joint.  The  patient  should  be; 
sitting  or  standing,  the  tube  bein^  in  front  and  near  the  median  line, 
with  its  anticathode  at  the  level  of  the  outer  end  of  the  clavicle,  and 
about  10  inches  from  the  nearest  surface.  The  fluoroscope  is  held 
behind  and  somewhat  to  the  side  of  the  shoulder. 

Fluoroscopy  of  the  shaft  of  the  humerus  presents  no  difficulties 
except  in  very  lar^e  persons,  and  in  one  of  the  author's  cases  an  oblique 
fracture  of  the  humerus  was  dressed  under  direct  observation  by  the 
x-ray .  In  this  case  the  contraction  of  the  different  muscles  caused  such 
an  overriding  of  the  oblique  surfaces  that  a  <rood  result  could  hardly 
have  been  obtained  in  any  other  way. 

Fluoroscopic  examination  is  much  less  successful  about  the  elbow- 
joint.  The  effusion  which  is  present  in  cases  of  recent  injury  has  the 


r 


.Y-rav  tubn   in    front    ;unl  platf  rvhiinl.      C:i~c  of  r-hronir  rhou- 


:•    iti-in  wjili  .-u-i-lliiiir  of  tlif  i-hoatli  "1   tin1  ulnar  nrr\r.      Klbuw  appear*  normal  in  radio- 


effect  'if  making  the  ./'-ray  inia.ire  cloudy,  and  in  any  case  the  thickness 
Mid  close  relation  of  the  bones  about  the  elbow-joint  mako  radiography 
the  preferable  method  of  examination. 

The   forearm,    wrist,    and    hand    are   simple   objects    for   lluoroscopic 

>  xaminat  ion,  bin   even  here  radiography  is  the  method  for  exact  diaii- 

no-iX      Yerv  nianv  times  a  needle  mav  be  searched  for  in  vain  with  the 

loroscope  and  be  revealed  bv  a  radiograph,  having  been  concealed  by 

•  use  bones  of  the  CM rpiis.      Fven  one  o!  the  less  pertect  radiographs, 
made  directly  on  bromid  paper  and  developed  without    any  dark  room, 

-  ;cceed  in  ;i  case  in  whicli  the  fluoroscope  falls. 

I !:  radiographing  the  si  i  milder  the  pat  ient  hail  bet  ter  lie  on  his  back', 

With    '  '•     under   the   affected  shoulder,  and  the   outer  edi^e  of  the 

!'!;:•>•  rai-e  ;  -oiin  \\  hat  from  the  table,  so  as  to  lie  at  a  riu'ht  angle  to  the 

direct  .      The   tube   is   placed    so   that    its   anticathode  IS 

"    river   a    point    '2    inches    internally    to    the   acromioclavicular 

i  '_':;  inches  from  the  plate.      Jf  both  shoulders  are  taken 


THE    .r-HAY 


1087 


for  comparison  it  is  host  to  take  them  at  the  same  time.  The  tube,  is 
over  the  median  line,  at  a  point  corresponding  to  the  level  of  the  acromio- 
clavicular  articulations,  and  a  single  large  plate  may  be  used,  or,  prefer- 
ably, two  10  ''  1  '2-inch  plates,  so  that  each  may  be  tipped  somewhat 
SO  as  to  direct  Iv  face  tin:  tube. 


' 


Such  a  picture  shows  the  clavicle  very  well.  but.  of  course,  not  so 
well  as  a  radiograph  taken  with  the  plate  in  front  of  the  -houlder  and 
t  he  t  u  be  behind,  and  at  about  the  level  of  the  acromii  iclavicular  art  icula- 
tion,  and  M  inches  from  the  median  line,  and  2o  inches  from  the  plate. 
The  length  of  exposure  for  a  shoulder  radiograph  will  vary  with  the  si/e 
of  the  patient:  for  a  InO-pound  man.  with  the  tube  in  front,  near  the 
median  line.  1-inch  spark,  oO  ma.  for  twelve  seconds  or  10  ma.  for  thirtv- 


loss 


MKDICAL    KLK<  TUHITY    AM)    HONTo'KX    HAY: 


six  second-  or  any  other  otiO  ma.  second  exposure,  without  intensifying 
screen.  The  same  exposure  with  the  tube  behind,  10  inches  from  the  me- 
dian line.  But  with  the  tube  behind  close  to  the  median  line,  o-inch  spark, 
3t>0  ma.  second.-  and  intensifying  screen.  The  last  exposure  gives  a 
view  of  the  upper  extremity  of  the  humerus  at  a  right  angle  to  the  first 
view  and  is  a  device  of  the  author's  indispensable  in  case  of  fracture  of 
the  neck  of  the  humerus. 

If  an  anteroposterior  view  of  the  humerus  is  required  the  patient  had 
better  lie  upon  his  back  with  the  arm  somewhat  abducted,  the  plate  need 
not  be  larger  than  S  x  10  inches,  the  point  of  chief  interest  being  at 
the  center  of  the  plate,  and  the  anticathode  over  the  same  point  and  23 
inches  from  the  plate.  Resistance  4  inches,  exposure  four  seconds  with 


•  >n  IIKI.  or  ;my  other  120  ma.  second  expo>ure  without  an  intensifying 
sen-en.  The  above  figures  are  fora  l~)0-pound  man  i  Fig.  "fill. 

To  radiograph  the  humeru.-  from  the  >ide  it  i-  not  necessary  that  the 
patient  -hould  lie  down:  the  plate  i-  held  between  the  arm  and  the  side 
<'t  the  body,  the  tube  beinu  ;it  the  oiit-ide  of  the  ;inn;  otherwise  the 
pl'oce—  i-  the  smie  a-  for  an  a  lit  eropo-t  erior  view. 

The  elbow  i-  radiographed  atiteroposteriorly  in  a  position  of  exten- 
-loti.  with  the  dorsiim  re-tin":  upon  the  plate,  which  i-  laid  upon  a  table 
alon-j-ide  of  which  the  patient  -it-  •  Kin'-.  ~iil  and  7o.~i  .  or  a  lateral  view 
l>e  taken  wit  h  t  he  elbow  semi  flexed  and  it  s  inner  -urface  re.-t  ini:  upon 
'he  plate  I- in-.  7f,r,  .  There  i-  one  po.-itioii  ill  which  the  head  of  the  ra- 
diu-  and  t he  ot her  bone-  which  take  part  in  the  elbow-joint  ca n  be  >ho\vn 
separately  1-iii.  7*17  .  The  (-Ibow  and  forearm  should  rest  upon  a  table, 
lietore  which  the  patient  i-  -eated.  The  hand  i.-  pronated  and  rests  on 


THK    J"-HAY 


1089 


the  table.  The  elbow  is  partly  flexed  and  the  elbow  as  a  whole  is  ro- 
tated as  far  as  possible.  A  thin  soft  pad  is  placed  over  the  elbow  and 
the  Albers  Schonberg  compression  cylinder  is  applied  to  immobilize 
the  elbow  in  this  somewhat  strained  position.  The  x-ray  tube  is 
somewhat  toward  the  outer  side.  In  either  case  a  10  \  12-inch 
plate  is  used,  and  care  is  taken  to  place  the  anticathode  directly  over 
the  space  between  the  articular  surfaces  of  the  humerus  and  radius. 
Distance  23  inches,  exposure  the  same  as  for  the  arm. 

For  the  forearm  the  patient  sits  at  a  table  with  the  supinated  fore- 
arm resting  on  the  plate.  An  8  x  10-inch  plate  will  show  the  whole 
length  of  both  radius  and  ulna  (Fiji.  7(58).  The  tube  should  be  over 


t'Tinl 


the  center  of  the  plate,  and  the  distance  from  the  anticathode  to  the 
plate  23  inches.  Exposure  about  the  same  as  for  the  arm  and  elbow. 
I'or  the  wrist  the  condition-  are  the  same  as  for  the  forearm,  the 
hand  generally  being  fiat  upon  the  table  in  a  position  of  pronation 
Sometimes,  however,  the  displacement  of  the  fragments 
fracture  is  better  shown  if  the  radial  side  of  the  wrist  is 
plate  and  the  ulnar  side  away  from  it.  This  position  re- 
the  plate  shall  be  held  vertically  and  the  wrist  supported 
II  this  cannot  be  conveniently  done,  almost  a;  good  a 
lateral  view  may  be  obtained  by  laying  t  he  plate  upon  a  table  and  rest  in  u.' 
the  radial  border  of  the  hand  and  wrist  upon  it.  The  portion  which  i- 


KM)!) 


MKD1CAL    KLKCTKiriTY    AM)    HoNTCKN     HAYS 


nearer  I  he  plait-  ^ives  the  clearer  linage,  and  this  is  the  reason  the  radial 
side  >hould  In-  next  to  1  he  plale  in  taking  a  lateral  view  of  a  Colics' 
t'ract  tire. 

A    more    recent    device   of   the   author's  employs    a    cardboard   box 
tran-parent    to   the  .r-ray.     The  patient's  wrist  rests  upon  this  not   ab- 


i     •     .  '  \    n     il  r-llxnv  .-md  furc:tnn.     Arm  arid  fnn -MTU  i  n- 1  in  i;  Hipinc  upon  th(?  plait1. 

-olutely  prone,  but  with  the  radial  -ide  rai-ed  a  little.  The  ./'-ray  tube 
i-  at  the  uinar  -ide  ;it  the  level  of  the  \vri-t  and  the  plate  is  vertical, 
with  it-  edufe  re-tirm'  on  the  table,  held  clo<e  aaarn-t  the  radial  side. 

Author's  Positions  for  Radiography  of  Colics'  Fracture.     One  S  x  10 
radiograph    -hows    both    wrists    prone   upon    the   plate.      Another  shows 


THE    £-11  AY 


10')] 


i'nth  wrists  \\-nh  their  ulnar  margins  upon  the  plate.  Imt  with  oaeh  hand 
MHiiewhat  everted  so  that  the  shadow  of  the  dorsum  of  the  radius  will 
ix>  external  to  thai  of  the  ulnar  and  five  from  it.  A  third  radiograph 
dunvs  hoth  wrists  with  their  ulnar  hord(Ms  resting  upon  tin-  plate,  the 


MKDICAL    KLK<  TKKITY    AM)    KO.NTCK.N     KAY. 


71  — Author'.-  second  position  for  radiography  ol   Colics'  fracture:  showing  dor.-a 


border  of  radius. 


ML',   r  i  _'.      .\  .••.••!   -  t  liirM  [id  it  idii  for  r:ir]idLrr:i|itiy  d)  (  'dllc.-    frari  urc  :  -crniprcii 


THK    .r-KAY 


hands  being  somewhat  inverted  so  that  the  palmar  margin  of  the  radius 
i<  free  from  the  shadow  of  the  ulna.  But  in  this  last  picture  the  dorsurn 
of  the  radius  is  obscured  by  the  ulna,  and  the  characteristic  displace- 
ment if  slight  is  difficult  to  make  out. 


To  secure  a  clear  image  of  the  radius  when  thus  held  away  from  tin- 
plate  the  anticathode  should  be  23  inches  from  the  plate.  The  patient 
-hould  hold  his  breath  during  the  exposure. 


Radiographs  of  the  carpus,  metacarpus,  and  phalange's  are  com- 
monly taken  with  the  palm  of  the  hand  flat  upon  the  plate.  If  the  whole 
hand  is  taken,  the  tube  should  be  far  enough  away  to  shine  between 
the  articular  surfaces  of  the  different  joints.  Twenty-three  inches  from 


1094 


MKDK  AI.    KLKCrHH'lTY    AM)    UONTCEN    HAYS 


the  antioathode  to  the  plate  is  the  best.  At  this  distance1  the  exposure 
would  l>e  seven  and  a  half  seconds  with  ',]()  ma.,  or  any  other  22f>  ma. 
second  exposure  for  a  150-pound  man,  resistance'  4  inches.  A  lateral 
view  of  individual  finders  is  often  useful  in  the  diagnosis  of  fractures  or 
dislocations  and  in  locating  foreign  bodies. 

A  bromid-paper  print,  made  directly  with  two  or  three  times  this 
exposure,  is  especially  useful  in  .r-ray  examination  of  the  hand.  It  can 
be  developed  in  the  operating  room  by  simply  darkening  the  room 
moderately,  and  the  whole  process  takes  less  than  five  minutes.  The 
imam1  is  better  than  that  visible  with  the  fluoroscope,  and  can  be  studied 


for  any  length  of  time,  thus  avoiding  the  dangers  attendant  upon  a 
prolonged  fluoroscopic  examination.  Duplitized  films,  with  a  short  ex- 
posure, are  better  if  a  dark  room  is  available  for  immediate1  development. 

The  Albers  Schonberg  Compression  Cylinder  in  Radiography 
of  the  Upper  Extremity.— As  indicated  in  the  case  of  radiography 
ul  the  elbow,  the  compression  cylinder  is  useful  for  immobilizing  the 
part  to  be  radiographed— hand,  wrist,  forearm,  elbow,  arm.  or  shoul- 
der.  It  is  useful  for  improving  the  definition  in  radiographs  of  the 
,-houlder  or  elbow,  but  elsewhere  in  the  upper  extremity  all  the  neces- 
sarv  detail  mav  be  obtained  without  it. 

Other  Convenient  Methods  of  Immobilization  of  the  Upper 
Extremity.— Sand-bags  may  be  laid  along  both  sides  of  the  limb. 
'Ill''  bill's  in  winch  .")  oi'  10  pounds  of  salt  arc  sold  serve  very  well  for 
tlii-  purpose.  The  salt  itself  is  all  right  at  first,  but  it  becomes  hard 
and  inflexible  after  exposure  to  a  damp  atmosphere.  Sand  alwavs 
remains  soft,  and  adapts  itself  to  any  surface  which  it  rests  against. 

A  device  suggested  bv  Johnston'  consists  of  a  long  cloth  bag  at 
each  end  of  which  is  10  pounds  of  shot .  Tin1  bag  is  laid  across  t  he  limb, 
and  the  hc;ivv  ends  hang  over  the  sides  of  the  table. 

The  author  and  some  other  operators  use  a  special  but  extremely 
j  Am.  Quarterly  of  lioiilncin.ln^y.  I!»u7. 


THE    X-RAY 


1095 


simple  bandage  for  immobilization.  A  wide  bandage  is  split  for  a  tew 
inches  near  the  middle,  one  cud  is  fastened  fit  one  side  of  the  table; 
the  bandage  is  carried  over  the  limb,  completely  around  it,  and  then 
through  the  opening  in  the  bandage  where  it  crosses  orer.  not  n  inter 
the  litnh,  and  thence  to  the  opposite  side  of  the  table  where  it  is  drawn 
tight  and  fastened.  This  has  the  advantage  of  preventing  rotation 
and  lateral  displacement  of  the  limb,  as  well  as  preventing  it  from  being- 
raised  from  the  table. 

Congenital  Lesions  of  the  Upper  Extremity  Revealed  by  the 
.r-Ray. — Joaehimsthal1  gives  thirty-three  excellent  radiographs  illus- 
trating these  different  conditions. 

('<)////(  nitul  ilixlix-iitioti  of  the  shoulder  is  quite  a  rare  condition, 
only  one-twentieth  as  frequent  as  congenital  dislocation  of  the  hip. 


Patient   now  seven  yeui'd  o 


A  case  reported  by  Porter."  and  also  seen  by  Hidlon,  shows  that  the 
radiographic  appearance  is  not  as  striking  as  might  be  expected.  The 
image  of  the  affected  shoulder  should  be  compared  with  that  of  the 
sound  shoulder  made  in  the  same  position,  or.  in  case  of  both  shoulders 
being  affected,  the  shoulder  of  a  normal  child  of  the  same  age  should  be 
radiographed  for  comparison. 

Congenital  Epiphyseal  Injury  at  the  Upper  Extremity  of  the  Hu- 
merus.  A  case  under  the  author's  rare  illustrates  the  radiographic 
diagnosis  of  congenital  injuries  at  the  shoulder  i  Figs.  77(1  and  777). 
The  pal  lent,  a  boy  of  seven,  was  said  to  have  been  taken  by  the  left 
arm  and  thrown  across  the  room  by  the  doctor  when  he  was  born. 
lie  was  never  able  to  move  his  left  arm  afterward.  \Yhen  examined 
there  was  tound  to  be  no  movement  at  the  shoulder-joint.  The  arm 
could  be  moved  only  to  the  extent  of  movement  of  the  scapula;  it  could 

(It'll.  (1.  Knnt.srcn..   l'.t(M).  Supplement   \<>.  '_'. 
1.  Journal.  August   Iv  1 '.»<><). 


10% 


MKDH  AL    KLKCTHH'ITY    AND    KOXTOK.N    HAYS 


not  he  placed  vertically  at  the  side  of  the  head,  and  the  hand  could 
not  he  put  hehind  the  hoy's  hack.  Muscular  power  was  ^ood  and  the 
hoy  could  cliinh  a  tree.  The  left  shoulder  looked  as  if  dislocated. 
There  was  the  sharp  tip  of  the  acroinion  process  and  helow  this  a  hol- 
low. The  head  of  the  hunierus.  however,  could  not  he  felt  either 
outside  or  inside  the  solenoid  fossa.  A  radiograph  was  made  of  the 
two  shoulders,  with  the  tuhe  in  the  median  line  in  front  and  a  plate 
hehind  each  shoulder.  The  head  of  the  hunierus  on  the  sound  side 
looked  as  larii'e  as  a  hen's  e<i<j;:  it  filled  the  irlenoid  cavity  and  the  space 
in-low  the  acroinion  process  and  projected  heyond  the  latter.  The 
-haft  of  i  he  riiiht  hunierus  was  lar^e  and  wi;ll  developed.  The  radio- 


^raplii'1  linage  on  the  left  side  was  radically  different:  the  head  of  The 
humerus  was  represented  hy  a  little  knoh.  '.  inch  in  diameter,  perched 
uti  top  of  the  upper  end  of  the  shall,  which  was  hardly  two-thirds  1  ho 
normal  thickness.  The  little  deformed  head  of  the  hiimerus  was  in  the 
natural  po-ition.  hut  did  not  nearly  fill  the  .-pace  heneath  the  acroinion 

i'i-""<_— 

I  here    \vus    not    the   material    for  a    normal   shoulder-joint,   and   the 
::.'  was  to  leave  the  shoulder  alone.      I)r.  Lorenx.  of  Vienna, 

•'•a-     ho\vn  the  radiographs  a1  St.  Bartholf)mew's  Clime,  also  said, 
''Nothing   to  he  donf." 

Supernumerary    bones    in    any   part    of   the   upper  extremity   arc 


THE    X-RAY 


1097 


readily  studied  by  means  of  the  x-ray.  Two  humeri,  two  ulriir,  and 
radii,  or  an  abnormal  number  of  metaearpal  bones  or  phalanges,  are 
found  in  different  cases.  The  information  thus  obtained  may  some- 
times be  put  to  practical  use  in  deciding  on  the  proper  surgical  treat- 
ment. Such  a  case  is  reported  by  Alarkoe.1  Figure  77X,  drawn  from  the 
skiagraph,  shows  a  supernumerary  metaearpal  bone  placed  transversely 
and  separating  the  heads  of  the  second  and  third  metacarpals  widely. 
The  second  picture  shows  the  improved  shape  of  the  hand  after  removal 
of  the  supernumerary  bone. 

Lund"  shows  interesting  radios-rapine  studies  of  cases  of  congenital 


deformity  of  the  phalanges,  congenital  absence;  of  the  scapula  or  of  the- 
radius,  and  similar  malformations. 

Mencke;i  reported  a  case  of  reduplication  of  the  index- finger.  The 
.r-ray  picture  showed  that  the  corresponding  metaearpal  bone  presented 
a  proximal  as  well  as  a  distal  epiphysis.  The  second  metaearpal  alone 
presented  this  peculiarity,  and  upon  this  he  founded  the  classification 
of  this  as  a  supernumerary  index-finger  instead  of  a  supernumerary 
thumb  with  three  phalanges.  Before  the  introduction  of  the  x-ray  28 
such  cases  had  been  reported,,  and  they  had  been  classified  indifferently 
as  extra  thumbs  with  three'  phalange's  or  as  e>xtra  index-fingers. 

Somewhat  different  is  the1  case'  shown  in  Fig.  77(.)  (radiograph  by 
Dr.  McKe-nzie  at  the  Yanderbilt  ('linic).  He'iv  there  we're1  apparently 
tin)  Ihuntli*.  One  of  these1  sprang  as  a  sort  of  e'\oste>sis  from  the  proxi- 
mal phalanx  of  the  thumb  and  had  a  single,  distal  phalanx  of  its  envn. 
This  was  fixed  in  a  position  of  flexion. 


II 


MKIUi  AI.    KLKt  TKHITY    AND    RONTGEN    KAYS 

Various  Anomalies  in  the  Carpus.-  These  have  been  studied  from 
anatomic  specimens  and  from  radiographs  of  living  subjects.1 

Radioscopy  in  Fractures  of  the  Upper  Extremity.-  The  treatment  of 
fractures  of  the  clavicle  and  scapula  is  not,  as  much  aided  by  the  .r-ray 
as  that  ot  tract  ures  of  the  other  bones  of  the  upper  extremity. 

\Jrnctnrt  oj  tin  u/t/xr  r.r//7 ///////  of  tin  hintuni*  usually  shows  little 
lateral  displacement.  The  diagnosis  is  based  upon  the  presence  of  a 
-harp  line  across  the  bone.  The  portion  above  the  line  is  broader  than 
the  portion  below  and  its  square  corners  project  on  each  side. 

I' /'net u/'t  oj  tin  i//'(iit(i'  tubcroxiti/  of  tin  h nt/n  /'//>•  should,  according  to 
Meszytka.-  be  looked  tor  in  all  doubtful  cases  of  injury  simulating 
Hibluxation  of  the  shoulder.  The  radiograph  should  lie  made  with  the 


plate  und'T  the  shoulder,  which  is  slightly  raised  by  a  cushion.  The 
a  I'm  should  be  adducted  and  minted  outward.  It  should  bo  fixed 
in  position,  and  the  exposure  should,  it  possible,  be  so  short  as  to  en- 

the  patient    to  hold  his  breath  during  its  continuance. 

A    case   of   supposed    dislocation    of   the   shoulder   was   subsequently 

shown   bv  the  ,/'-rav  to  be  a  frnrtnrt'  of  lln1  xiii'i/iriil  in  r/c  of  thr  hiunrrHS 

with   displacement    outward  of  the  upper  fragment    and   inner  disphice- 

•    lower  traii'inent.      The  case  had  been  treated  as  one  of  dis- 

location;    ih^rc    had    been    union    in    malposition,    and    the   case   formed 

r..   .IllU    L's,    1  ',t(lti. 


TIIK    .C-HAY  1099 

the   basis  of  a   law-suit    against    the   physician,   in   England,   who  had 
taken  care  of  it,.1    (See  page  10S7  for  technicj 

Fracture*  of  the  *hajt  of  tin1  ku merits  are  readily  inspected  by  the 
x-ray  and  the  possible  overriding  and  bending  may  be  avoided  by  up- 
plying  the  dressing  under  .r-ray  guidance. 

Fracture*  of  t lie  loicer  extremity  of  the  humeru*  present  several  different 
forms,  and  the  fluoroscopic  image  will  be  found  of  the  greatest  possible; 
assistance  in  getting  the  fragments  into  position.  This  may  make  the 
difference  between  a  permanent lv  impaired  elbow-joint  and  one  which 
is  perfectly  useful. 

Keen2  reports  a  case  of  operation  for  nun-union  after  fracture  of  the 
humerus.  The  .r-ray  showed  the  presence  of  the  aluminum-bronze 
wire  one  year  after  the  operation,  but  two  years  later  tin;  wire;  had 
entirely  disappeared. 

A  fracture  of  the  olecrnnon  )>rocc**  of  the  ulna,  will  show  very  well 
in  a  lateral  radiograph  or  in  an  anteroposterior  radiograph  with  the 
plate  behind.  There  is,  in  the  anteroposterior  picture,  a  perfectly 
normal  appearance  of  a  transverse  line  across  the  olecranon  process, 
at  the  level  of  the  superior  articular  surface1  of  the  radius.  This  must, 
not  be  mistaken  for  a  fracture.  The  latter  produces  wide  separation, 
not  a  mere  transverse  line. 

Fracture*  of  the  *Ji<(fi  of  the  radiu*.  or  ulna,  or  both,  are  seen  in  the 
fluoroscopic  or  radiographic  image,  and  overlapping  or  lateral  displace- 
ment on  bending  may  be  discovered  even  after  the  splints  have  been 
applied.  One  of  the  author's  patients  was  a  four-months'-old  baby,  with 
bones  only  the  size  of  pipe-stems,  and  such  a  fat,  chubby  forearm  that 
the  bones  could  not  be  felt. 

One  of  the  author's  radiographs  showed  a  "green-*tick"  fracture  of 
the  radiu*  in  a  child  ten  years  of  age  which  had  not  been  suspected  by 
the  parents  until  the  development  of  a  lump  due  to  the  formation  of 
callus  at  the  seat  of  injury.  The  line  of  fracture  was  visible  and  also 
the  callus,  but  there  was  no  bending  or  displacement. 

Nat  rig3  also  reports  2  cases  of  long-standing  tenderness  in  the  wrist 
which  the  .r-ray  showed  to  be  due  to  old  unutnted  fracture*  of  different 
bones  in  the  carpus. 

Colli  N'  fracture  of  the  lower  extremity  of  the  radius  is  one  in  which 
some  little  study  is  required  to  make  the  .r-ray  of  real  service.  Two 
radiographs,  are  required  for  the  diagnosis  of  this  condition.  One  is 
made  with  the  hand  and  forearm  placed  fiat  upon  the  plate  arid  the 
tube  over  the  back  of  the  wrist  at  the  seat  of  fracture.  A  fracture 
•>hows  a  transverse  line,  which  represents  the  broken  surface  of  the 
lower  fragment.  Square  corners  of  this  project  on  either  side,  because 
thi-  fragment  is  wider  than  the  portion  of  the  upper  fragment  which 
it  overlaps.  No  lateral  displacement  is  usually  seen  in  a  dorsopalmar 
radiograph. 

A  second  picture  is  made  in  a  lateral  direction,  which  shows  the 
line  of  fracture  and  the  dorsal  displacement  of  the  lower  fragment. 
The  edge  of  this  fragment  shows  especially  clearly  upon  the  back  of  the 
wrist.  This  lateral  radiograph  is  made1  with  the  radial  side  of  the 

.  til. 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

wrist  on  the  plate  and  the  ulnar  side  a\vay  from  it,  but  the  wrist  is 
turned  a  little  so  that  the  ray.  passing  from  the  tube  in  a  vertical  line 
through  the  radius.  goes  through  the  open  air.  not  through  the  ulna  or 
the  soft  parts  of  the  wrist.  The  proper  posit  ion  is  very  simply  obtained 
by  having  the  patient  crouch  down  at  the  side  of  the  table  on  which 
the  plate  is  laid  and  resting  the  radial  border  of  his  hand  on  the  plate. 
This  can  be  arranged  in  much  less  time  than  any  other  position,  bat- 
is  rather  crumped,  and  in  the  case  of  a  recent  injurv  would  be  found 
painful.  A  more  comfortable  position  for  the  patient  is  obtained  by 
the  use  of  the  author's  lateral  plate-holder.  The  forearm  and  hand  are 
supported  in  a  natural  position  of  semipronaiion.  the  plate  is  held 
vertically  tit  the  radial  side  of  the  wrist,  and  the  tube  is  at  the  ulnar  side. 
A  preliminary  glance  with  the  fluoroscope  will  venfv  the  correctness  of 
the  position.  A  lateral  radiograph  of  the  wrist  .-hows  the  profile  of 
the  dorsuiu  <>f  the  radius,  but  the  other  structures  of  the  wrist  form  a 
confused  mass  from  the  overlapping  of  their  shadows  on  the  plate. 

Fractures  of  the  carpal  bones  are  correctly  radiographed  with  the 
palm  of  the  hand  resting  upon  the  plate  and  the  tube  vertically  over  the 
bark  of  the  carpus. 

An  old  un  united  fracture  <>f  the  xenjihoid  Innic.  which  had  given  symp- 
toms  .-uppo.-ed  for  more  than  two  years  to  indicate  rheumatism,  sprain, 
tenosynovitis,  or  tuberculous  periostitis,  was  discovered  by  Hammond1 
by  means  of  a  radiograph.  The  fragments  of  the  scaphoid  bone  were 
freed  from  intervening  fibrous  tissue  and  united  by  silver  wire  with  a 
perfect  result . 

FrnrturcH  of  tin  ///< /amr/xil  honex  are  about  the  only  ones  of  the  upper 
extremity  which  are  apt  to  escape  detection  by  the  fluoroscope,  and 
they  sometimes  require  careful  study  to  determine  by  means  of  radiog- 

liy.  The  difficulty  is  due  to  the  fact  that  there  is  seldom  any 
lateral  displacement.  The  bone  is  bent  toward  the  palm  of  the  hand 
and  thi-  llexion  does  not  show  in  a  dorsopalmar  view,  and  the  line  of 
fracture  is  also  apt  to  be  indistinct  in  this  view.  Twisting  the  hand 
so  that  the  different  metacarpal  bones  may  be  viewed  from  tin;  side 
enable-  one  to  make  certain  of  the  diagnosis.  A  lateral  radiograph  of 
the  first,  second,  or  fifth  metacarpal  bone  is  easily  obtained  by  placing 
i  he  radial  or  the  ulnar  border  of  the  hand  in  con t act  with  the  plate,  while 
'lie  other  border  of  the  hand  is  away  from  the  plate  at  an  angle  of  about 
4.~>  deirrees.  The  x-ray  from  the  tube  passes  obliquely  over  the  back  of 
t  tie  hand.  The  metacarpal  bone  at  the  border  of  the  hand  which  is  in 
'•ontacl  with  the  plate  shows  verv  distinctly,  while  the  other  shows  less 
.-learly. 

A  Special  Device  of  the  Author's  for  Lateral  Radiography  of  all  the 
Metacarpal  Bones.-  The  object  is  to  have  the  plate  practically  in  con- 
•;iH  with  all  the  metacarpal  bones  and  thus  to  secure  clear  images  of 
all  of  them.  The  hand  i.-  placed  palm  down  on  the  plate  and  the  tube 
i-  placed  over  the  back  of  the  hand,  but  so  far  to  one  side  that  the 
average  alible  of  the  rays  pa.ssing  through  the  metacarpal  bones  is  }."> 
deon-i--.  The  picture  'Fig.  7<Mh  is  one  in  which  the  shadow  oi  bones  is 
wider  than  nat  ural.  but  t  his  can  be  offset  by  looking  at  t  lie  pict  lire  from 
an  Miiule  ol  !."»  decree-  instead  of  holding  it  perpendicular  to  the  line  of 
vi-ion.  I'  i-  also  practicable  to  make  a  photographic  copy  of  such  a 

I'll  :      '        Mcf|.  Sor..  Nov.  '!'.',.  100};  X.  Y.  M<-,1.  Jour.,  !•'«•! 


THK  :T-KAY 


1101 


picture  hold  at  an  angle  of  45  decrees,  and  thus  obtain  a  picture  in 
which  I  he  hones  are  the  natural  width. 

The  object  sought  is  a  clear  picture  of  the  different  nietacarpal 
bones  at  as  near  an  approach  to  a  lateral  view  as  is  possible  without  over- 
lapping of  their  images. 

In  the  case  of  a  fracture  at  the  distal  epiphyseal  line  of  one  of  the 
nietacarpal  bones  the  presence  of  a  fracture  may  be  revealed  by  a  dorso- 
palmar  radiograph,  though  the  amount  of  bending  is  not  shown. 

Heck1  gives  a  radiograph  showing  a  lateral  view  of  a  fissured  frac- 
ture of  a  nietacarpal  bone  which  did  not  show  in  a  dorsopalmar  radio- 
graph. 

Fracture  of  the  base  of  a  nietacarpal  bone  may  be  diagnosed  by 
means  of  a  dorsopalmar  radiograph  and  sometimes  by  means  of  the 


Huoroscope.  According  to  Duroux.-  the  functional  result  in  the  case  of 
the  first  nietacarpal  is  generally  good  because  reduction  can  he  per- 
fectly accomplished.  Fractures  of  the  bases  of  the  second  and  third 
metacarpals  often  leave  the  wrist  in  such  a  condition  that  flexion  is 
painful,  and  fractures  of  the  bases  of  the  fourth  and  fifth  metacarpals 
often  result  in  persistent  neuralgic  pain.  Bennett's  fracture  of  the 
base  of  the  inetacarpal  bone  of  the  thumb  is  shown  in  several  radiographs 
by  l!uss.:; 

The  <  piph  i/*«i!  I/IK   shows  such  a  complete  separation  between  1  he 
bonv  tissues  of  the  shaft   and  the  head  of  a  metatarsal  bone  in  vounu 


1102  MEDICAL    ELECTRICITY    AM)    RONTGEN     RAYS 

persons  that  the  author  has  known  these  lines  to  be  mistaken  for  mul- 
tiple tract  ures  by  one  unaccustomed  to  radiographs. 

Fractures  of  the  Phalanges.  It  is  so  easy  to  obtain  both  a  lateral 
and  a  dorsopalmar  lluoroscopic  view  of  the  phalanges  that  there  will 
be  no  difficulty  in  recogni/ing  a  fract  ure  wit  h  any  displacement .  Simple 
tissures  might  escape  detection  with  the  ordinarv  box  lluoroscope 
and  be  readily  found  with  the  author's  magnifving  fluoroscope.  A 
single  radiograph  might  not  show  a  fissured  fracture  unless  it  happened 
to  be  taken  in  the  most  favorable  direction.  To  be  positive  two  radio- 
graphs should  be  taken  at  a  right,  angle1. 

A  low  degive  of  vacuum  in  the  .r-ray  tube  is  desirable  fe>r  radiograph- 
ing the-  phalanges — resistance  4  inches.  There  is  very  little  tissue1  to 
be  penetrated,  and,  of  course,  the  lower  degrees  of  vacuum  proeluce 
radiographs  with  much  greater  contrast.  Here,  as  elsewhere,  the 
more  intenx1  the  raeliance,  the  shorter  will  be1  the  exposure,  and  a  nor- 
mal exposure  for  a  150-pound  man  at  23  inches  without  an  intensify- 
ing screen  would  be'  o()  ma.  for  three  seconds  or  any  other  (.M)  ma.  second 
exposure1. 

Dislocation  of  the  Shoulder. — The  examination  is  made  with 
the'  tube  in  front  of  the  shoulder  and  towarel  the'  meelian  line.  The 
plate*  or  the1  fluorescent  screen  is  placeel  behind  the'  shoulder  and  its 
outer  eelge  is  further  forward  than  the'  other.  The-  head  of  the  humcrus 
is  seen  an  inch  or  two  from  its  normal  position,  where1  it  should  fill  out 
the  space  extending  outward  from  the'  glenoid  cavity  and  under  the 
acromion  process. 

Kven  in  a  very  stout  person  it  is  possible  to  show  this  condition, 
though  the  plate  is  necessarily  thinner  and  the  picture  fainter  than  in  a 
slight  person. 

Dislocation  of  the  Elbow. — A  backward  dislocation  is  shown  in  a 
radiograph  made  with  the  inner  surface  of  the  elbenv  resting  on  the  plate 
and  the  lube  over  the  outer  surface.  A  lateral  dislocation  is  shown 
in  a  radiograph  made  with  the'  back  of  the1  elbenv  resting  upon  the  plate 
and  with  the  tube  over  the'  front.  It  may  not  be  practicable  to 
straighten  the  elbow  on  account  of  pain.  In  this  case',  the'  point  of 
the  elbow  mav  rest  on  the  plate,  and  the  arm  and  forearm  are1  at  about 
tin1  same  angle  from  the  plate  and  the  tube  is  in  the  angle  between 
them,  at  a  di>1ance  of  12  inches  from  the1  anlicathode  to  the  plate. 
The  radiographic  -hadows  of  the  bones  are  almost  the  same  as  if  the 
elbow  were  straight,  e-xcept  thai  while  the  image  is  <|uite  clear  near  the 
e-lbow-joinl  the  shadows  of  the  upper  part  of  the  arm  and  the1  lower 
part  of  the  forearm  are  enlarged  and  vague. 

Fracture-dislocation  of  the  elbow  is  shown  in  Fig.  781. 

Subluxations  of  the  head  of  the  radius  occur  more  commonly 
than  \\  a.-  former! v  supposed.  A  small  child  is  walking  be-ide  its  mother, 
who  is  holding  one  hand,  the  child  stumbles,  and  the  mother  gives  a 
jerk,  whie-h  lifts  the  child  to  its  feet  and  injure-  its  arm.  There 
•rtain  amount  of  pain  and  swelling  ami  the  hand  cannot  be1  su- 
1  he  .r-ray  examination  is  not  an  easv  one.  The 
-.  and  will  not  hold  hi-  arm  .-till  while  the  radio- 
in  o.-t  practicable  method  is  to  have  a  celluloid 
I  inches  wide,  wrapped  in  light-proof  envelopes 
od  -plint  or  a  strip  of  heavy  cardboard.  The 
fn ml  of  tli 


THE    .r-HAY 


bandage.      The  ai'in  may  then  be  held   up  before  the  x-ray  iul>e,  \vliich 
is  behind  the  elbow  and  a  little  to  its  radial  -ide. 


Dislocation  of  the  Joints  in  and  About  the  Hand. — These  require 
the  same  technic  as  fractures  of  the  same  region. 

Details  of  the  Soft  Parts  in  a  Radiograph  of  the  Hand. — The 

best  radiograph  of  the  hand  is  taken  with  a  low  decree  of  vacuum,  so 
as  to  have  threat  selective  absorption,  and  with  a  high  decreed  intensity, 
so  as  to  impress  every  detail  upon  the  plate,  and  a  sufficient  length  of 
exposure  so  as  not  to  require  abnormally  long  development.  The 
lechnic  already  described  is  as  good  a  general  guide  as  can  be  suggested, 
but  experiment  at  inn  with  one's  own  apparatus  will  perfect  the  results. 

The  outline  of  the  llesh  shows  as  well  as  that  of  the  bones,  and  every 
difference  in  the  thickness  of  the  soft  tissues  is  brought  out.  Certain 
differences  in  densit  v  are  revealed :  t  he  nails,  for  instance,  show  perfectly 
well,  and  faint  outlines  of  some  of  the  muscles  and  tendons  are  visible. 
As  man\'  as  eight  distinct  shades  of  color  may  be  made  out  on  a  good 
plate. 

The  arteries  do  not  usually  show.  If  they  show  distinctly  it  is  an 
evidence  of  at  heroma. 


104 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


Radiographs  Showing  the  Cutaneous  Markings. — These  are  made 
by  a  sort  of  trick.  Powdered  bismuth  subnitrate  is  rubbed  into  all 
the  creates  of  the  palmar  surface  of  the  hand  and  fingers  for  the  picture 
made  with  the  palmar  surface  on  the  plate,  and  into  the  grooves  around 
the  finger-nails  ami  all  the  creases  on  the  back  of  the  hand  and  fingers 


f  the  lower  oxtromitv  of  the  humerus  with  backward  displacement 


I'lastrr-of'-Paris  splints  front   and  hack 


i<>r  the  dorsal  picture.      Bismuth  is  so  opaque  to  the  .r-ray  that  it  casts 
a  .-hadow  showing  all  the  natural  markings  of  the  -kin. 

Functionally  Good  Results  After  Fractures.  Radiographic 
Appearances.  Tonw1  suinman/es  the  tacts.  Before  the  discovery 
nf  the  .r-rav  we  believed  that  the  anatomic  results  were  much  better 
than  iln1  radiograph  now  shows  them  to  be.  The  latter  has  established 
an  ideal  as  to  the  result  which  it  is  often  impossible  to  attain  and  which 
ii!  ino.-t  cases  would  have  no  advantage  for  the  patient.  The  practical 
ideal  is  to  secure  a  good  functional  result  without  deformity,  recogniz- 
able by  the  unaided  senses.  The  r-ray  shows  that  very  few  oblique 
fractures  of  the  leg  or  arm  are  treated  without  shortening  and  other 
deformities.  One  x-ray  picture  ma}'  exaggerate  the  deformity  just 
a-  another  may  '-onceal  it.  It  is  unjustly  exacting  as  to  the  results  of 
t  r;n't  nre-  in  lega  1  cases. 

Radiographic  Appearance  of  Callus  After  Fractures.      Recent  callus 
i-  not   opaque  to   the  .r-ray.  but    permanent    callus,  or   that    which   has 
changed  into  bone,  is  similar  to  natural  bone  in  opacity. 
1  Jour.  Am.  Mcil.  Assor..  Jiiix-  2.  I'.MHI. 


THK    X-HAY 


110.1 


RADIOSCOPY    IN    DISEASES   OF   THE   BONES   AND   JOINTS 

TABLK  OK  DISKASK.S  OK  TIIK   BONKS   AND  JOINTS   IN  WHICH    ./-KAY   KXAMI.  NATIONS. 

AUK.   i  >K  SKI:  \  ICK  ' 


xti-i/i*.      Spina  ventnsa. 

sfi/'t/*  Dfjiinininx.     -A  fieri  s  i>ntli  None  and  perin.-ieinn. 
x/i'i»>ti/<-i/tix.      Aliscess,  ni  •(•(•(  »is,  se<|iie>t  ra. 
I    Keijt'iicrafion  of  Hunt   Ajhr  ()/>i-ru/i<»/.      ('allus  t'orriiat  inn. 
'"•"]    Tuhcri-H/oxix.—  Nearly  ahvavs  in  epiphytes,  sunict  imcs  in  j<< 
Syphilis. 

A'/r/.r/.s.     Coxa  vara. 
.  t  rrnnii  </<i/  1/. 
(  Chronic  Pulmntmry  Oxtm-nrtln-n/Hitlii/. 


{  ( 'arcinoma  <  rare). 


f  Rheumatoid  arthritis  (atrophy  of  hone  and  all  joint 

,    ...    ,,   •  structures). 

T   •  Arthritis  iJefornuins.  \   ,  \    •' •    ,  •  \ 

Joints  -,  j  Osteo-arthntis  (hypertrophy  oi  hone  and  cartilages). 

1   ( 'harcot 's  disease. 
Rfii  >n»ntix»i.  —  Acute  and  chronic. 
i  Gout. 

)r/><>nitx  iihni/t  joint*.  including  urate  of  soda  or  lime  salts. 
,<mse  Cnrtilnrje. 


RADIOGRAPHY  IN  TUMORS   OF  THE  BONES  AND  JOINTS 

Radioscopy  of  bony  tunior.s  enublos  one  to  cliff e rent iatr  neoplasms 
from  osteomyelitis  and  syphilis  and  to  sec  whether  the  tumor  is  enrapsu- 
latrd  or  diffuse,  whether  it  is  accompanied  by  fracture,  and  whether  there 

are  metastases. 

Tumors  about  the  shoulder  sometimes  require  an  .r-ray  examination 
to  determine  whether  they  are  of  bony  origin  or  are  of  the  soft  parts 
only.  One  of  my  patients  had  a  tumor  resembling  a  sarcoma  of  the 
shoulder,  but  the  radiograph  showed  normal  bony  tissues.  An  operation 
was  performed  by  the  author  on  very  different  lines  from  what  would 
have  been  required  had  the  .r-ray  shown  bony  involvement.  The  tumor 
proved  to  be  a  fibroma. 

Sarcoma  is  characterized  in  the  radiograph  by  swelling  and  rare- 
faction of  the  bone  affected,  and  this  is  apt  to  be  of  a  rather  general 
distribution  in  the  affected  part  of  the  bone. 

An  interesting  case  was  referred  to  the  author  by  Dr.  Clallant. 
Then1  had  been  pain  and  swelling  about  the  knee  following  a  slight 
fall  sustained  two  months  previously.  The  radiograph  showed  that  a 
practically  spontaneous  fracture  of  the  femur  had  occurred.  There  was 
very  little  about  the  radiographic  appearance1  to  suggest  more  than  a 
simple  fracture,  except  the  fact  that  the  bone  was  soft  enough  at  the 
place  of  fracture  to  permit  of  impaction.  This  would  hardly  be  expected 
to  occur  in  a  woman  twenty-four  years  of  age  with  a  normal  femur  and 
bending  of  1.1  degrees  as  was  the  case  here.  A  microscopic  examination 
made  the  diagnosis  certain  and  the  thigh  was  amputated. 

Slightly  altered  from  Williams,  "The  llontiicn  Itay  in  Medicine  and  Suruery.'' 
70 


110(3 


MEDICAL    KLECTKIflTY    AND    KO.NTCiEN    RAYS 


It  is  sometimes  more  and  .-omet imes  less  difficult  to  see  just  whore  a 
tumor  ends  in  the  hone  than  is  the  case  with  other  diseases  of  hone. 

Carcinoma  when  it  occur-  in  bone  presents  a  radiograph  similar  to 
that  of  sarcoma.  The  differential  diagnosi>  is  based  upon  the  history 
and  other  similar  considerations. 

Benign  cysts  occur  in  bone,  and  are  seen  in  the  radiograph  as  large, 
sharply  defined,  rounded  areas  of  translucency.  Such  a  cavity  was 


' 


A 


found  1  iv  1  he  a ut  dor  in  a  case  <,f  tic  douloureux.  It  was  very  small  and 
i:i  :  port  ion  of  t  he  lower  \-,\\-  t'ro/n  which  t  he  t  eet  h  h,-id  long  ,-ince  been 
extracted. 

Kxo-to-es    -how   as    projection-,    sometime-   ot    normal    bony    ti--ue, 
ninetime-  of  r;ire|ied  or  of  unnaturally  den.-e  bony  tissue,  depend- 
in',     ipi  in   t  he  c;iti-''  of  the  '•  >>idi'  loll. 


ACROMEGALY 


THE    X-HAY 


1107 


enlargement    of   the   hones,    both   in   length   and   thickness.     This  was 
especially  marked  in  the  great  toe. 

BONY  CHANGES   SHOWN   BY   RADIOGRAPHS  OF  CASTRATED  ANIMALS 

L.  Hichon  and  P.  Jeandelize1  find  that  rabbits,  which  are  castrated 
when  young,  show  certain  bony  changes  when  adult.  Their  radiographs 
show  elongation  of  the  long  hones  and  increase  of  weight;  these  changes 
being  most  marked  in  the  posterior  extremities. 

OSTEOMYELITIS    AND   NECROSIS 

These  may  he  regarded  for  the  purpose  of  .r-ray  diagnosis  as  different 
stages  of  the  same  disease  — the  stage  of  inflammat  ion,  and  the  subsequent 
stage  during  which  nature  attempts  to  remove  the  dead  bone  produced. 


L10S 


MEDICAL    ELECTRICITY    AND    KONTGEN    RAYS 


Tin-  gradual  formation  of  an  involucruni,  or  enveloping  sheath  of 
newly-formed  hone  around  the  dead  portion,  may  he  observed  in  a 
series  of  radiographs.  The  hone  eventually  looks  twice  the  natural 
size,  and  may  not  present  the  usual  appearance  of  canccllous  tissue 
or  mveloid  canal. 


ACUTE  OR    CHRONIC   PERIOSTITIS 

These  eases  show  a  somewhat  irregular  projection  beyond  the  outline 
of  the  hone,  which  is  usuallv  distinctly  \-isihle.  The  density  of  the 
perio>tea]  .-welling  is  at  first  only  slightly  irreater  Than  that  of  the 
overlyin.if  flesh,  hut  as  the  case  becomes  chronic  more  and  more  irreg- 
ular bony  tissue  <hows  in  the  swelling. 

A   CASE   OF  OBSCURE  DISEASE   OF  THE  SHOULDER 

A-  a  very  younir  inrl   the  patient    had   been   treated  by  electricity 

f»r  -ome  trouble  of  a  neurit  ic  oj-  paralytic  type  about  t  he  riidit  shoulder, 

bu)     the    treatment    had    been    discontinued    because   she   seemed    to    be 

able  to  use  the  arm  fairlv  \ve!l.      After  this  she  swam  and  played  tennis, 

hi;'     ihvays   had    to  swim:  the  body   a   t:ood   deal    in   order  to  assist    the 

'    the   arm.       Six  years  or  more  had   elapsed   when   an   acute 

of  intense  pain   in   the  shoulder  occurred.      Thi<  was  diagnosed 

it  i- m,  and  t  lie  a  nu  was  kept  immobihxei]  for  six  or  eiu'ht  weeks. 

and  a   -ur^ical   examination   then   revealed  almo.-t    complete  absence  of 

'!.••  -lioulder-joint .      Then  followed  a  -cries  of  most   vigorous 

'"   try  to  break  up  suppo.-ed  adhesions.      This   was   very 

pain!  il.   and  n  imiier  of  week-  produced   no  improvement   and 


THK    J-KAY 

was  abandoned.  The  idea  of  forcibly  breaking  up  the  supposed  ad- 
hesions under  ether  was  under  consideration  when  Dr.  T.  M.  Lloyd 
referred  her  to  the  author  for  /-ray  examination. 

At  this  time  practically  no  voluntary  motion  could  he  made  at  the 
shoulder-joint,  but  passive  movements  of  rotation,  as  we'll  as  forward 
or  backward  or  to  either  side,  were  possible  for  .">  or  10  decrees.  \  olun- 
tary  movement  of  the  arm  was  almost  entirely  accomplished  by  motion 


of  the  scapula,  and.  of  course,  was  very  limited.  There  was  marked  atro- 
phy  of  the  deltoid  muscle  and  the  muscles  of  the  arm.  The  patient  could 
not  raise  her  rkdit  hand  to  shake  hands  or  to  carry  food  to  her  mouth. 
She  made  all  such  motions  bv  liftinir  the  n'uht  forearm  with  the  left 
hand. 

An  .r-ray  examination  was  made,  which  showed  a  perfectly  normal 
left  shoulder  and  (Fig.  786  made  in  the  same  position)  a  most  unnatural 
condition  of  the  ri^ht  shoulder. 

The  disease  seemed  to  affect  chiefly  the  head  of  the  Innnerus.  which 
was  flattened  on  top  and  had  lo>t  the  natural  uniform  convexity  of  its 
art  icular  surface. 

It  was  evident  that  the  material  fora  normal  ball-and-socket  joint 
\va-  absent,  and  that  forcible  breaking  up  of  the  articulation  would  have 
produced  serious  injury. 


1110  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

Treatment  l>y  high-frequency  currents  applied  from  vacuum  elec- 
trodes had  a  somewhat  restorative  effect  upon  the  muscles  but  left  the 
joint  unimproved. 

A  long  course  of  treatment  has  been  conducted  by  Dr.  Shaffer, 
who  considers  the  case  one  of  tuberculosis.  A  brace  has  been  used  to 
prevent  motion  at  the  shoulder-joint  and  support  the  weight  of  the  arm 
and  at  the  same  time  permit  of  the  use  of  the  limb.  There  has  been 
great  improvement  in  muscular  power. 

A  corroborative  fact  in  favor  of  tuberculosis  is  the  development  of 
a  case  of  ] lulmonary  t ui >erculosis  in  one  of  the  patient's  brothers. 

The  case  is  one  which  has  pu/zled  .some  of  the  best  surgeons  and 
orthopedists  in  this  country  and  Kurope,  and  the  varying  diagnoses  of 
rheumatism,  osteomyelitis,  and  tuberculosis  have  all  been  regarded  as 
verified  by  the  appearance  found  in  the  radiograph. 

It  shows  the  importance  of  an  .r-ray  examination  at  the  earliest 
po-v-ible  moment  in  every  case  of  joint  disease.  If  this  case  had  been 
radiographed  at  different  periods  from  its  earliest  manifestation  the 
diagnosis  might  have  been  certain  and  much  useless  suffering  from 
unavailing  manipulation  avoided. 

SYPHILIS  OF  THE  BONES 

This  disease  presents  itself  for  x-ray  diagnosis  in  two  general  groups-. 
1.  Svphilhic  gumma;  2,  syphilitic  inflammation. 

Gumma  of  Bone. — Wherever  this  specific  neoplasm  occurs  the  radio- 
graph .-hows  a  combination  of  a  destructive  and  a  proliferating  process. 

Some  part  of  the  bone  is  usually  rarefied,  another  part  may  be 
denser  than  normal,  and  there  is  often  an  increase  in  the  size  of  the  por- 
tion <  it  bone  affect  ed. 

The  Periosteal  Type  of  Gumma. — A  considerable  number  of 
radiographs  have  been  published  of  this  variety  of  the  disease.1 

The  typic  Rontgen  picture  of  syphilitic  gumma  of  bone  shows  the 
shaft  of  the  tibia,  for  example,  presenting  at  one  side  a  perfectly  normal 
outline  and  the  normal  thickness  of  corticalis  in  the  normal  relation  to 
the  rnedullarv  canal,  while  on  the  other  side  the  corticalis  is  thinned 
bv  irregular  patches  of  rarefaction  and  its  uniform  outline  can  no  longer 
be  traced,  the  periosteum  is  intact  over  a  swelling,  which  shows  more  or 
le.-s  ossificai  ion. 

At  the  extreme  margins  it  is  quite  easy  to  see  that  the  swelling  is  a 
periostea!  one.  because  there  the  bony  contour  is  preserved  with  the 
jess  dense  shadow  of  the  periosteum  gradually  springing  away  from  it. 

A  commencing  ^umma.  with  a  slight  periostea!  swelling,  hardly  at  all 
ossified,  and  with  verv  little  rarefaction  of  the  corticalis.  might  not  be 
distinguishable  bv  the  r-ray  alone  irom  traumatic  periostitis. 

The  Myeloid  and  the  Cancellous  Types  of  Bone  Gumma. — These 
b'"jin  on  the  inner  surface  of  the  corticalis  of  the  shaft  or  in  the  cancel- 
lou-  tissue  of  the  epiphysis.  Neither  of  these  present  marked  charac- 
teristic- bv  which  t  hey  may  always  be  easily  distinguished  by  the  x-ray 
alone  from  tuberculosis,  sarcoma,  and  other  diseases. 

i  Koliler,  I  or1  a.  'I.  f!«-h.  (I.  Kocnt.,  vn],  x,  \r>.  '1.  7.",,  I'lOC,;  Knoclicncrkrank- 
unir'-ii  im  I;-"  ;>: L"  nMH".  .1.  I1'.  I'cnrniann :  Ihilni,  Kontircn  Congress,  l!i()<>:  Halm 
iui'1  Df-yckf.  Knoriirii--y|iliilH  ini  KocnttrcnbiMc,  l!»(»i:  Hitter,  Wicn.  klin.  Woch., 
J'JUT,  No.  i'>,  p.  ic,j;  Ware,  . XimaN  of  Surgery.  Anirii-t,  1!K)7.  p.  I'.i'.t. 


THE    X-RAY 


111 


I"JLr.  7^7.-  (iunniia  of  the  soft  parts  not  affecting  the  inctatarsal  hone.       (Radiograph  by 
Dr.  B.  P.  Riley,  St.  Bartholomew's  Clinic.) 


L'.  "ss. — Gumma  of  the  radius  and  of  tin- first  nictatarsul  none.       (Radiofrranh  bv  Mr. 


Brush.  Mctronolitan  Hosi)ital.  '• 


Th<\v  arc  both  myelogonous,  arising  in  1)1^  marrow  either  of  the 
nivel'me  canal  or  the'  marrow  of  the  spaces  in  the  eancellous  tissue  of 
t  he  epiphysis. 


1112 


MKO1CAL    KLK(  TKU1TY    AND    HONTliKX    HAY 


Phey  are  apt  to  exist  in  the  same  bone  l>y  extension  from  one  part 
to  another. 

Fiti'im-  7S8  i  Mr.  Brush)  shows  this  condition. 

Spina  Ventosa  Syphilitica. — This  disease  affords  a  good  example 
of  a  myelogenous  .minima  of  bone.  One  of  these  fingers  presents  a  fusi- 


S;  •  liilitif    nrthriti-   of   thr  kneo.      ("Rauinjrrnjih   }iy    Mr.    Hrush,  Metropolitan 


form  -weUini:  ;ti)out   a  joint  without   much  redness  or  pain  and  with  a 

low  proirress.      It  feels  bony,  but  as  if  the  bony  wall  was  as  thin  as 

ii  ctrir-shell.      The  radiograph  shows  marked  rarefaction  of  the  epiphy- 

-    and    the   iieiti'hborin.iz  part    of  the  shaft    ot    the   affected  bone.      The 

llous  tissue  of  the  epipliysis  ma\'  be  largely  absorbed  and  the  bone 

ken.     Then-   is   a    periostea!   swelling,   which    ]»i'esents   a   varying 

amoui  '  of  o-sification  in  different  cases. 

formation   of   new   bone   is   about    the  only   feature   which   dlS- 
tin'j",'  hi'-   -uch  a  r-asc  radioirraphicallv  fi'om  tuberculosis. 

The     .  ithor   ha-    seen    cases   of    spma   \'enlo.~a    m    which    the    radio- 
i:ra])hic   a  ;tuce  did    not  enable  us  to  differentiate  l»etween  syphilis 

and  -imple  o.-tenniyelitis.      The  hi.- lory  in  one  ca>e  pointed  to  hereditary 
r-yjihilis. 


THK    Z-KAY 


A  case  of  gumma  of  theepiphysisof  the  radius  is  reported  by  Koehler, 
which  the  racliographic  appearance  alone  would  not  have  enabled  one  to 
different iatc  from  sarcoma.  His  description  of  the  radiograph  is  as 
follows:  The  entire  bony  structure  of  the  proximal  half  of  the  radius  is 
verv  much  altered.  The  shaft  is  somewhat  rarefied  from  the  middle  to 
the  t  uberositv  and  the  thickness  of  the  corlicalis  is  reduced.  The 
sponu'v  tissue  of  the  epiphysis  has  almost  completely  disappeared.  The 
compact  tissue  of  the  epiphysis  is  irregular  in  outline  and  reduced  to  the 
t  hick  ness  of  paper  and  has  protrusions  at  different  places.  The  articular 
surface  of  the  head  of  the  radius  is  practically  normal.  The  only  differ- 
ence between  this  and  the  radiographic  appearance  of  a  sarcoma  is  that, 
in  the  latter  case,  there  is  usually  a  sharply  defined  dividing  line  be- 
tween the  diseased  and  the  sound  bony  tissue. 

SYPHILITIC  INFLAMMATION   OF  THE  BONES    NON-GUMMATOUS) 

A  patient  suffering  from  syphilis  is  peculiarly  liable  to  every  form 
of  acute  or  chronic  bony  lesion  which  may  be  covered  by  the  broad  term 
Inflammation.  Some  of  these  are  quite 
similar  to  simple  inflammatory  pro- 
cesses of  the  same  type,  but  very  often 
t  he  .r-ray  will  show  a  decided  difference; 

A  radiograph  of  a  patient  at  St. 
Bartholomew's  Clinic,  with  a  somewhat 
tender  fusiform  swelling  of  the  tibia, 
showed  that  this  was  a  pure  hyperpla- 
>ia  and  sclerosis.  The  other  factors  m 
the  history  confirmed  the  impression 
derived  from  the  radiograph  that  the 
process  was  due  to  hereditary  syphilis. 

Ware  calls  attention  to  the  occur- 
rence of  syphilis  in  joints,  especially  the 
elbow,  secondary  to  syphilitic  osteo- 
chondritis  at  the  epiphyseal  line.  The 
upper  epiphyseal  line  of  the  radius  is 
hit  ra-articular. 

The  secondary  results  of  gumma  of 
bone  show  in  a  radiograph  taken  at  a 
later  stage.  There  may  be  exostosis. 
hyper<  ><to<is.  or  osteoscierosis.  and  some 
of  these  are  difficult  to  distinguish  ra- 
diographically  from  similar  results  fol- 
lowing acute  osteomyelitis  or  sometimes 
healed  1  uberculosis. 

Riley's1  diagnostic  sign  of  syphilis 
con-q<ts  m  an  obliteration  of  the  medul- 
lary canal,  or  a  lack  of  differentiation 
between  the  cortex  and  canal  even  in 
exceedingly  gooi  1  radi<  (graphs  of  the  long 
bone-.  He  has  noted  t  his  abnormal  ap- 
pearance even  in  ot  her  bones  than  those 
in  which  symptoms  had  been  present. 

1  I  )r.  1'.  B.  Hilev,  personal  communications  apropos  of  several  rase 
the  author  for  nidiographic  examination. 


Radiographs  made  at  different 
referred  to 


1114 


MEDICAL    ELECTRICITY    AND    KON'TGEN    HAYS 


~t  :i<j.e~  <  if  i  re;it  menl  and  cure  sho\v  u.  return  1o  normal  differentiation  of  the 

medullary  c;i!i;il. 

BONE   SYPHILIS   IN   ANIMALS 

Yon  N'ii'--(-ii  ha-  ]iul dished  ;t  valuable  scries  of  radiographs  (made 
1 -y  Koohler  iliii-t  r;i  i  inn-  the  sulijcrt  (if  syphilis  nf  idc  hones  in  animals 
artifici  'iilalcil  \villi  thai  disease.'  They  <\\<  <\\'  t  he  same  lesions 

a-  in  t  IK-  case  «\  men      e\<  i<t<  >.-is  of  the  inner  side  (if  t  he  r\\x.  periostitis, 
o>-ifie;it  i<  in  df  the  ril)-.  i  p-tc(ich«indritis. 

1      :•      ;  :      ...}.<  ich.  tier   liociitsicn.,  vol.  vi.  p.    IsS.    1«.K|J. 


THE    X-RAY 

RICKETS 

The  characteristic   radiographic    appearance 


1115 


in  a  long  bone  of  a 
rachitic  child  is  seen  at  the  line  i>et\veen  the  hone  and  the  cartilage. 
An  irregular  zone  of  ossification  extends  into  the  clear  osteoid  tissue. 
The  bowed  legs  and  oilier  deformities  which  often  result  from  the  dis- 
ease are  shown  in  radiographs  and  the  latter  furnish  valuable  informa- 
tion as  to  the  part  of  the  bone  at  which  an  operation  should  be  per- 
formed or  brace-pressure  applied  (Fiji;.  791). 

THE   JOINTS    IN   RHEUMATISM 

The  radiographic  appearance  is  described  under  a  grouping  based 
upon  Mussor's  "Medical  Diagnosis"  (Philadelphia,  1900).  It  will  be 
understood  that  the  x-ray  alone  will  not  always  enable  us  to  differentiate 
between  these  diseases.  It  will  almost  always,  how-over,  show  that  the 


a   chair-invalid   in   spite- of  treatment 


1'iir.  I'.'L'.  —Rheumatoid  arthritis.     Patient    I  wan 


i  >y  hi^h-frcqucncy  current.-  and  tl 


case  belongs  to  this  group  of  diseases,  and  not,  for  instance,  to  tubercu- 
losis or  malignant  disease.  The  author  makes  an  x-ray  examination  in 
every  case  of  this  class  of  disease  which  lie  treats.  It  is  of  the  greatest 
assistance  in  diagnosis  and  prognosis.  A  finger-joint,  showing  ankylosis 
with  continuous  bony  structure  between  the  two  phalanges,  as  in  one  ol 


lilt)  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

the  author's  e-ases,  is  not  going  to  be  restored  to  functional  usefulness 
by  high-frequency  currents. 

Acute  Articular  Rheumatism.-  This  disease  is  accompanied  by  acute 
fever.  It  occurs  in  early  life.  There  is  swelling  and  redness  of  one  or 
metre  large1  joints.  This  may  be1  fugitive,  leaving  one  joint  and  attack- 
ing another.  It  does  not  tend  to  attack  the1  same1  joints  on  both  sides 
of  the1  boely  symmetrically. 

The1  .r-ray  shows  no  change1  in  the1  bones.  Effusion  into  the  knee- 
joint  is  almost  always  recognizable  in  the1  radiograph,  the1  floating  patella 
and  the1  pouch  under  the1  quadriceps  tendon  being  evident. 

Chronic  Articular  Rheumatism.^ This  is  a  disease  of  later  life; 
the1  history  of  heredity  is  very  marked.  It  affects  several  of  the  large1 
joints,  especially  the  shoulder  and  the  knee.  There  is  spontaneous  pain 
as  we'll  as  te'udcrness  most  of  the  time,  but  with  exacerbations,  due  in 
some  of  the  author's  cases  to  weather  changes  in  either  direction.  There 
is  no  impairment  of  usefulness  in  these  joints  between  attacks,  except 
in  some1  verv  chronic  cases,  where  there  is  stiffness  or  even  fibrous  anky- 
losis. 

It  is  distinguished  from  chronic  gout  by  the  fact  that  it  presents  no 
spe-cial  tendency  to  affect  the1  great-toe  joint  or  to  produce  deformities 
by  a  de-posit  of  sodium  urate  in  the1  ears,  fingers,  and  about  the1  joints. 

Rti(lio(/r(i])liic(tlli/  these1  joints  present  very  little1  change,  the  bones 
show  no  rarefaction,  and  it  is  only  in  very  chronic  case's  that  there  is 
some  irregularity  in  the  bony  outline  and  an  unnaturally  close1  apposition 
of  the1  articular  surfaces,  indicating  partial  absorption  of  the1  cartilages. 

THE  JOINTS   IN  GOUT 

This  is  a  disease1  whose1  diagnostic  features  are1  the1  presence  of  uric 
acid  in  the-  blood,  a  deposit  of  seielium  urate'  in  the1  jeiints  and  either 
tissues,  a  marked  hereditary  predisposition,  the  fact  that  it  is  brought 
on  e.-peciallv  by  errors  as  to  fooel  ami  drink,  and  the  occurrence  of  certain 
digestive  and  nervous  disorders.  The  trouble1  very  often  attacks  the 
great  -toe  joint . 

Acute  Articular  Gout. — This  may  not  in  the1  early  attacks  show 
any  change  in  the  radiographic  appearance-  of  the-  joint,  but  later  some 
of  the  changes  of  chronic  gout  mav  be  found. 

The  y-rav  examination  of  a  joint  affected  by  an  attack  of  acute 
Sioul  shows  that  the  bones  are  normal,  and  enables  us  at  once  to  exclude 
osteomvelit  is,  which  these  cases  sometimes  resemble. 

The  presence  of  uric  acid  in  the-  blood  is  determined  by  means  of  a 
.-imple  test  applied  to  serum  from  a  blister.  A  little  acetic  acid  is  added 
;<i  the  serum  and  a  thread  is  placed  in  it.  After  being  kept  twelve1  or 
r  \vnt  v-four  hours  at  a  low  temperature  typic  uric-acid  crystals  will 
colled  on  t  he  thread. 

Chronic  Articular  Gout. — This  is  a  disease  characterized  by  de- 
furmitv  of  the  affected  joints,  deposit  of  sodium  urate  in  the  articular 
rar'il.-1'.M's.  ligaments. and  bursa1.  and  the  presence1  e>f  gouty  tophi  in  the 
ear  and  about  the  joint  s. 

Tl  >  radiographic  appearance  of  the  bone-  is  not  usually  very  much 
C-hanged.  evepl  that  their  articular  surface.-  may  be  unusually  close 
together,  i  nd  lack  senne  of  the  rounded  appearance  present  eel  when  they 
are  covered  by  normal  cartilage.  Deposit.-  of  uric  acid  wherever  they 
occur  are  clearly  visible-  in  the  radiograph,  forming  a  mass  more-  opaque 
than  the  lle.-h  but  not  -o  opaque  a.-  bone. 


THE    X-RAY  ill/ 

A  gouty  tophus  consists  of  a  spongy  mass  of  fibrou.-  ti»ue  whose 
meshes  are  filled  with  a  white  pasty  substance.  It  shows  as  a  clearly 
defined  though  not  very  dense  mass  in  a  radiograph. 

THE  JOINTS  IN   RHEUMATOID  ARTHRITIS   OR  RHEUMATIC   GOUT 

This  is  a  disease  which  often  seems  to  be  caused  by  repeated  preg- 
nancies or  by  privation,  and  is  of  slow  and  intermittent  but  determined 
progress  without  fever.  There  is  no  special  hereditary  influence  and 
no  uric  acid  in  the'  blood.  The  vast  majority  of  the  cases  are  subacute 
or  chronic. 

It  is  essentially  a  bilateral,  symmetric  disease  of  many  small  articula- 
tions, but  some  larger  joints  may  also  be  involved.  Subluxation  of  the 
finder  joints  or  of  larger  joints  may  occur.  There  may  be  changes  in  the 
outline  of  the  joints  due  to  absorption  or  to  osteophytic  processes.  The 
osteophytic  growth  may  cause  loss  of  mobility  in  the  affected  joints. 

The  hand  in  a  typic  case  of  rheumatoid  arthritis  presents  a  character- 
istic deformity.  Kvery  finger  is  more  or  less  affected.  The  first  phalanx 
is  either  flexed  or  extended  and  the  last  phalanx  is  either  flexed  or 
extended;  there  mav  be  simply  flexion  of  the  first  phalanx  while  the 
others  are  st  raight .  The  hand  is  pronated  and  the  fingers  turned  toward 
the  ulnar  side.  The  ends  of  the  phalanges  may  be  enlarged. 

Uheumatoid  arthritis  differs  from  chronic  articular  rheumatism  in  its 
bilateral  and  polvarticular  character,  the  absence  of  acute  attacks 
brought  on  by  climatic  conditions,  the  greater  deformity  produced,  and 
the  possible  involvement  of  the  articulations  of  the  spine.  Chronic 
rheumatism  is  more1  apt  to  affect  the  heart  and  to  present  a  history  of 
chorea. 

The  radiographie  appearance  in  rheumatoid  arthritis  corresponds 
with  the  apparent  condition  of  the  joint.  The  articular  ends  of  the 
bones  present  the  normal  degree  of  translucency  to  the  .r-ray,  but  there 
are  irregular  knob-like  projections.  Some  of  these  appear  more  trans- 
parent, and  others  have1  about  the  same  transparency  as  ordinary  com- 
pact itone.  In  one  such  case  the  joint  ben  ween  the  proximal  and  the 
second  phalanx  of  the  left  index-finger  was  permanently  and  irretriev- 
ably ankylosed.  There  is  continuous  bony  structure  right  through  this 
joint.  The  case  is  one  which  was  sent  to  the  author  for  treatment,  and 
it  was  important  to  know  the  condition  of  the  different  articulations. 

HYPERTROPHIC  ARTHRITIS   OR   OSTEO-ARTHRITIS 

This  is  a  slowly  progressive  disease  occurring  in  later  life  and  in 
both  men  and  women.  The  joints  are  enlarged,  painful,  and  tender. 
Formation  of  new  tissue  takes  place  at  the  junction  between  bone  and 
articular  cartilages,  and  this  new  tissue  becomes  calcified,  forming 
Heberden's  nodes,  but  these  eventually  break  down  and  destroy  the 
contour  of  the  articular  .-urface.  A  radiograph,  made  at  this  time,  will 
show  a  very  irregular  disorganization  of  bone,  which  can  easily  be 
differentiated  from  the  more  or  less  symmetric  destruction  seen  in  the 
atrophic  type  of  art  hrit  is.1 

Chronic  osteo-arthritis  is  the  name  given  by  l.avensoir  to  a  case  in 
which  radiographs  by  Pfahler  showed  that  some  of  the  joints  in  the  fingers 
were  obliterated  bv  fibrous  or  bonv  union,  and  others  in  the  fingers  and 
haiuls  by  the  absorption  of  bony  tissue.  There  were  several  luxations. 

Fitch.  X.  V.  Staff  Journal  of  Medicine,  vol.  vii,  Xo.  7.  April.  1<M)7.  p.  141. 
.lour.  Am,  Mr.1.  Assnc..  .l:m.  Ji'..   I '.107. 


1118 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


Some  entire  phalanges  were  absorbed.     The  process  doubtless  involved 
other  portions  of  the  body,  but  only  the  hands  were  radiographed. 

CHARCOT'S   JOINT -THE   TABETIC  JOINT 

A  typic  case  of  this  disease  presents  a  large  white  swelling  of  a 
single  large  joint,  especially  the  knee,  without  tendency  to  flexion,  and 
with  decided  relaxation  of  the  ligaments  from  wasting  of  the  articular 
end.-  of  t  he  bones. 

The  cartilages  are  eroded,  osseous  deposits  occur  in  the  ligaments, 
and  irregular  exostoses  occur  around  the  joint  (Fig.  70o). 

Dislocation  of  the  hip  may  occur  from  wasting  of  the  head  of  the 
femur. 

Spontaneous  fracture  of  the  pelvis  or  of  the  upper  part  of  the  femur 
may  occur  (cases  reported  by  Liebold.1  Fere  and  Durand,  and  Wilms). 
Though  they  are  rare,  they  should  be  taken  into  account  in  cases  of 
supposed  sarcoma  or  tuberculosis  of  the  hip. 


["he  boric--  Jn  not   show  rarefaction  as  in  either  of  these  oilier  con- 


1  -.  but.  on    the   contrary,  exo.-io.~e-   ;ind    irregular   hyperplasia    a: 


GONORRHEAL   ARTHRITIS 

Thi-  u-uaiiy  involves  the  knee-joint,  bui  sometimes  the  wrist  or 
pome  o'l.i-i  joint.  There  i-  r;irelv  destruction  oi  bone  or  anv  bony 
le-ion  rccoiiiii/.-dili'  by  the  x-ray. 

I     r-   •  •  I.  (  i.-li   rj    i{(M-ntui-n.,  vol.  X.  N'o.  '-'.  i>.  77.  I'.KHi. 


THE    X-UAY 


1110 


Figure  7<>1,  p.  K)S('),  is  of  an  dhow  from  which  several  ounces  of  gon- 
orrhea! pus  had  been  evacuated  a  few  months  previously,  and  Fig.  7<).j 
shows  a  hip-joint  from  which  several  ounces  of  pus.  'also  containing 
gonococci,  were  evacuated  a  few  months  after  this  examination. 

Neither  of  these  radiographs  show  any  visible  abnormality.  Of 
course,  if  pus  had  been  present  at  the  time  the  radiographs  were  made 
the  fact  of  fluid  in  the  joint  would  have  been  discovered  by  the  radio- 
graph. Pus  shows  about  the  same  density  as  water  or  as  the  soft  tis- 


siie>  i 'f  i  he  body.  Inn  a  considerable  collect  ion  of  any  kind  of  iluid  almost 
alwav-  .-how-;  a  di-tmci  boimdarv  m  the  radiograph. 

(  'ases  of  destruction  from  an  morrheal  arthrii-  are  rare  and  -how  a 
radiographic  appearance  -imilar  to  ihat  of  tuberculosis. 

(  'ases  of  ankylo-i-  are  not  -o  uncommon.  '1  he  radiograph  does  not 
-how  bony  ti-.-ue  extending  aero--  the  .-pare  between  the  bone-  nor 
exo-to-e-  about  them.  The  process  is  one  of  fibrous  tissue  formation. 


ill2<)  MEDICAL    ELECTRICITY    AND    RONTGEN    HAYS 

TUBERCULOSIS   OF    BONES    AND   JOINTS 

The  principal  feature-  are  <l<  *trurlion  and  sitlilu.rtitio>i. 

The  ,r-ray  shows  at  first  increased  translucency,  then  some  loss  of 
detail  in  t  he  bony  si  ruct  ure.  and  then  wasting  away  of  t  he  part  affected. 
There  is  usually  no  tendency  to  the  production  of  exostoses  nor  to  the 
depo.-it  ot  bony  tissue  in  peno.-teal  swellings. 

The  areas  of  rarefaction  are  sometimes  so  clearly  defined  as  to 
indicate  practically  tubercular  abscesses  of  bone.  In  other  radiographs 
the  rarefaction  of  the  bone  presents  no  sharply  defined  border  separating 
it  fn  iin  the  unaffected  bone. 

It  is  a  very  important  fact  that  the  increased  translucency  extends 
beyond  the  limits  of  actual  disease.  There  is  more  or  le-s  i'a refaction  and 
atrophy  of  other  bones  beyond  these  limits. 

Reiative  Diagnostic  Value  of  the  ,r-Ray  and  the  Tuberculin 
Test. — \V.  S.  Haer  and  II.  W.  Kennard  discuss  the  diagnostic  value 
of  tuberculin  in  orthopedic  surgery.1  It  gives  an  earlier  diagnosis  in 
some  cases  of  tubercular  joints  than  is  obtainable  by  the  radiograph 
almie. 

The  ophthalmotuberculin  test  is  extremely  simple  and  convenient 
and  does  not  cause  fever  or  other  constitutional  disturbance.  A  few 
drop.-  in  the  eye  are  said  to  cause  a  local  reaction  there,  if  tuberculosis 
i.-  present  in  any  part  of  the  patient.  It  is  not  mathematically  certain 
however. 

Tuberculosis  of  the  Hip. — For  this  disease  see  p.  lOtii). 

Examples  of  Tuberculosis  in  Other  Joints  and  Bones. — A  valu- 
able series  of  radiographs  has  been  published  by  K.xner.2 

They//-*/  <•<!*<  was  one  of  swelling  of  the  carpus,  three  months  old,  and 
having  had  a  fistula  for  two  weeks.  The  radiograph  showed  tubercular 
changes  in  the  proximal  part  of  the  metacarpus.  There  was  also  a 
noticeable  translucency  in  the  distal  part  of  the  metacarpus  and  in  the 
phalanges.  The  compact  tissue  is  markedly  thinner  than  normal,  and 
the  cancellous  tissue,  especially  in  the  heads  of  the  metacarpal  bones 
and  phalanges,  is  very  much  decalcified,  but  the  fine  detail  of  structure 
was  .-till  visible. 

Tin-  xcro-i'id  cnsc  was  of  a  nine-year-old  child,  with  pain  and  swelling  in 
the  knee-joint  for  a  year.  During  the  first  month  of  the  disease  the  child 
had  been  able  to  walk,  but  since  then  it  had  been  kept  in  bed  by  pain. 
Tin-re  was  a  contracture  of  the  knee-joint.  Active  motion  was  impos- 
sible ;ind  there  was  passive  movement  to  only  a  limited  extent.  The 
radiograph  showed  tubercular  changes  in  the  joint  and  a  much  higher 
degree  of  old  atrophy  of  the  femur,  tibia,  and  fibula.  The  femur, 
especially,  showed  thinning  of  the  cortical]-. 

tlii r<!  rn.-:i  had  a  fungat ing  tuberculosis  ol  the  right  carpus.      The 
wed    tuberculosis    of    the    carpus   am 
i  li-t  a!  (-nds  of  t  he  met  acarpal   bones 
h  v  ot  t  hese  bom  -s. 

id   suffered    very  slight    pain    in   the   hand   for  six 
onths  there  had  been  a  .-mall  .-welling  on  the  back 
Ula    hail   formed   and   the  process   had  extended   until 

•piiced.     The  radiograph  showed  tubercular  changes 
the    proximal    parts   ot    the    metacarpus,   a    marked 

in-   Mopkin-;  Ho.-pital,  Hi.  Ki  I'.'dl. 

1.  (Jcb.  il.  Kuentfrcn.,  vol.  vi,  No.  I.  p.  7.  I'.K)2. 


THE    X-RAY  1121 

thinning  of  the  compact  tissue,  and  a  wide-meshed  appearance  of  the 
cancellous  tissue  at  fhe  distal  part  of  the  metacarpus  and  of  the  pha- 
langes. Atrophy  was  visible  in  this  case  within  two  months  after  the 
beginning  of  the  tubercular  process. 

The  _//////  case  had  a  swelling  of  the  back  of  the  hand  for  six  years, 
with  a  fistula  for  practically  the  whole  of  that  time.  There  was  very 
little  movement  at  the  wrist-joint.  The  radiograph  showed  tuberculosis 
of  the  carpus  and  metacarpus  and  also  old  atrophy  of  the  heads  of  the 
metacarpal  bones  and  of  the  phalanges. 

The  sixth  case,  a  child  six  and  a  half  years  old,  had  suffered  when  two 
years  old  with  a  swelling  of  the  left  knee.  After  a  long  time  an  abscess 
formed  which  left  a  fistula.  For  the  last  year  movement  of  the  joint, 
had  been  impossible,  but  the  fistula  had  healed.  The  radiograph 
showed  subluxation  at  the  knee-joint  with  the  changes  due  to  a  healed 
tuberculosis.  Besides  this  there  was  old  atrophy  of  the  femur  and 
tibia,  with  marked  reduction  in  the  amount  of  the  corticalis.  The 
atrophy  of  the  fibula  had  reached  a  much  higher  degree,  perhaps  be- 
cause the  lateral  displacement  of  the  tibia  had  removed  the  weight  of 
the  body  from  the  fibula. 

The  seventh  case  had  suffered  for  two  years  previously  from  an  injury 
uo  the  right  elbow.  This  was  followed  by  pain  and  swelling  which  lasted 
for  only  a  short  time.  Ankylosis  in  a  position  of  extension  gradually 
followed.  The  radiograph  shows  subluxation  and  that  the  joint  sur- 
faces are  practically  destroyed  by  a  tubercular  process.  In  addition, 
there  is  unnatural  translucency  of  the  humerus,  radius,  and  ulna  in 
the  neighborhood  of  the  joint.  An  operation  showed  that  those  parts 
were  not  affected  by  the  tubercular  process. 

The  eiahth  case  had  noticed  for  five  months  a  swelling  of  the  left 
ankle-joint  with  considerable  pain  on  motion.  Two  months  before  the 
.r-ray  examination  an  incision  was  made  over  the  inner  malleolus  from 
which  pus  exuded  as  a  permanent  fistula.  The  radiograph  showed 
destruction  of  bone  in  the  astragalus  and  the  os  calcis.  The  peripheral 
ends  of  the  tibia  and  fibula  and  the  healthy  bones  of  the  tarsus  were 
strewn  with  translucent  spots.  These1  spots  had  indistinct  outlines  and 
seemed  to  lie1  in  the  cancellous  part  of  the'  bone. 

Several  other  e-ases.  shown  in  Fxner's  radiographs,  presented  these 
atrophic  e'hangvs  in  the  bones  of  the  foot  from  tuberculosis  of  the1 
ankle;  or  in  the  bones  of  the  hand  from  tuberculosis  of  the  elbow. 

EXAMPLES    OF   THE    VALUE    OF   THE    X=RAY  IN   THE  STUDY  OF  ANATOMY 

Figure  7(.*r>,  a  radiograph  of  a  fish,  was  made  with  the1  portable'  high- 
frequeney  coil  apparatus  (Browne1.  Salem.  Mass.). 

Figures  T'.'t)  SO;-)  are  raeliographs  showing  t  he'  inje'cted  blood-vessels  of 
normal  human  subjects.  They  were  made  for  the1  author  by  Mr.  Brush 
of  t  he  Met  ropolitan  1  lospital. 

Rontgen   ray  may  lie  used  in   studying    postmorte'in    anatomy 
any    limitations   as   to   length   and   strength   of   exposure1,    and 
1  advantage1  derived  from  absolute'  immobility  ami  the  injection 
ilood-vessels  and  other  hollow  organs  with   e>paque  substances 
transparent    gases.      Pictures   produced   in   this  way   show   the' 
•ssels    in    their    natural    relation?-,    undisturbed    by    elissect ion. 
hollow  and  solid  abdominal   viscera  with  a 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


Fi<_'.  7U5.-  Radiograph  <>f  a  fish. 


THE    £-KAY 


HIM 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


I  i:'    ,'•>>.  —  Injected  iirterie-  of  t  lie  Confirm,  including;  t  lie  deep  palmar  arch. 


THE    X-RAY 


1 1 25 


1120 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


THE    X-RAY 


112S 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

r~ 


THE  X-RAY  1120 

more  clearly  defined  outline  than  is  possible  during  life,  with  its  respi- 
ratory, circulatory,  and  peristaltic  movements. 

The  diagnostic  value  of  these  pictures  lies  in  their  use  as  charts  for 
the  interpretation  of  radiographs  made  from  living  patients.  The 
author's  radiograph  of  the  different  pneumat'c  sinuses  of  the  face  filled 
with  lead  shot  are  examples,  and  also  Proust  and  Sefroit  's1  radiographic 
studies  of  the  topography  of  the  pelvic  organs.  r\  ne  latter  show  espe- 
cially the  relations  of  the  injected  blood-vessels  and  the  ureters. 

ANATOMIC   AGE   DETERMINED    BY   RADIOLOGY 

The  late  Dr.  Kotclr  introduced  a  >ystem  of  determining  the  develop- 
ment of  t he  child  and  its  fitness  for  work  in  the  school  or  the  gymnasium 
or  the  factory,  by  radiographs  showing  the  osseous  development  of  the 
wrist.  The  following  is  his  table  of  ossification  as  determined  radio- 
graphically: 

A.      First  yr;ir ( >s  magnum,  uneifonn. 

H.      Second  to  third  year ( )s  magnum.  unciform,  lower  epiphysis  of  radius. 

( '.      Second  to  third  year ( )s  magnum,  uncit'orm,  radius,  cuneiform. 

1).     Second  to  third  year ( >s  magnum,  uncifurm,  radius,  cuneiform,  semilunar. 

K.     Third  to  fourth  year ()s  matumm.  uncit'orm,  radiu>.  cuneiform.  M'miluiuir. 

trapezium,  or  scaphoid. 

Filth  to  Mxth  year Os  magnum,  uneifonn,  radius,  cuneiform,  semilunar, 

trapezium,  scaphoid. 

Sixth  year Os  magnum,  uncit'orm.  radius,  cuneiform,  semilunar, 

trape/ium,  scaphoid,  trape/oid. 

Sixth  to  seventh  year ( )s  maiiiium.  uncit'orm,  radius,  cuneiform,  semilunar, 

trapezium,  scaphoid,  lower  epiphysis  of  ulna. 

1.       Sixth  to  seventh  year Same  as  jjroup    II  as  to  number  of  bones,  but  more 

advanced  in  development. 

.1.      Seventh  to  eighth  year.  .  .  .Same  as  jjroup  I,  but  more  advanced  in  development. 

K.      Ninth  to  eleventh  year.  .  .  .Same  as  <rroup  .1,  but  the  pisiform  bone  appears  just 

under  cuneiform,  and  all  the  carpal  bones  and  epi- 
physes  are  much  more  massed  and  further  ad- 
vanced in  development. 

I..  Seventh  to  twelfth  year.  .  .Same  as  ijroup  K,  but  much  more1  advanced  in  devel- 
opment; pisiform  appears  plainly  at  lower  end  of 
cuneiform. 

M.    Twelfth  to  fourteenth  year .  Very    much    more    advanced    in    development    than 

firotip  L,  and  the  pisiform  bone  almost  as  larfie  as 
the  cuneiform.  All  the  bones  of  the  wrist  are  much 
more  developed  than  in  any  previous  <iroup. 

I)  and  K  correspond  to  the  kindergarten  period.  F.  G,  and  II  to  the 
school  period,  and  L  and  M  to  the  minimum  factory  period.  The 
method  is  sufficiently  accurate  to  be  a  valuable  factor  in  discovering 
evasions  of  the  child  labor  laws,  and  in  preventing  overstrain  at  work  or 
play  in  the  case  of  children  with  ret  an  led  development.  The  literal  lire 
of  ihi-  subject  has  been  tabulated  by  Skinner. "  and  includes  articles  by 
Long  and  ('aldwell  i  1(,)11  I,  Koger  l!N)s>.  Pryor  i  l<>o:>.  UHlti,  and  1908), 
Kotrh  i  I'.HM)  and  1(.)  10),  and  Smith  i  191M>.  Tlie  last  mentioned  feels  that 
the  method  is  of  little  value  in  the  case  of  naval  cadets,  eighteen  to 
twenty-two  years  of  au'o.  It  >hoiiid  be  applied  at  an  earlier  period  and 
then  may  indicate  future  fitness  for  the  work. 

1  P:iri<  Sucii'te  Anatomique,  March  '27.   I'.Hls. 

-  The  Development  of  the  Hones  in  Karly  Life.  Studied  by  the  1'ont^en  Method 
for  the  1  ). •term ination  of  an  Anatomic  Index.  Trail-action  Amer.  1'hys.  Assoc.,  vol. 

.\\i\-.  p.  lit':1,,  I'.iu'.t. 

1  Interstate  Medical  .Inurnal.   Mav.   l!»i:i. 


lloO  MKIHCAL     Kl.K<  THlrlTY     AM)     KnXTCJKX     KAYS 

DETECTION   OF  PEARLS    IN  OYSTERS 

The  tiiu>worn  method  has  been  to  open  the  shell  and  kill  the  oyster. 
This  results  in  the  needless  destruction  of  millions  of  pearl  oysters 
containing  no  pearls  and  of  thousands  of  oysters  in  which  there  are  seed 
pearls  which  would  increase'  ten-fold  in  value  if  the  oysters  were  allowed 


to  live  another  year.  Experiments  by  the  author  evolved  a  method  for 
radiographing  121  oysters  at  a  time  and  the  process  has  been  in  actual 
il>e  in  (  'eylon. 

Tin-  ('/untie  Kfl'rct*  <>f  th<  .r-Iitii/. — These  are  not  striking.  Starch 
i-  -lowly  changed  into  dextrin  by  .r-ray  exposure. 

Water  exposed  to  the  .r-ray  for  one  hundred  hours  showed  no  scpara- 
ii'  in  of  oxygen  and  hydrogen  gases.1 

PHYSIOLOGIC   EFFECTS   OF   THE   XRA.Y 
FROM    MILD   APPLICATIONS 

A    -innle   mild   exposure   produces   no   perceptible  effect,   but   some- 

•  -en-ation  i>  felt  a^  of  proximity  to  a  source  of  static  electricity. 

••  picture  or  niakiim  a  fluoroscopic  examination  is  an  example  of 

ilicat  ic  in. 

(  '  persons  notice  a  perception  of  liirht  when  their  eyes  are 

'  \:  ii  •  -'-•  iv     1  )•  irn  and    Flit  hol'f  i . 

'I "•.  ha~    liecn   found   to  constitute  a    very  delicate  te<t   for  the 

pre-encc  Vllier-  Sch/'piibci-g'-'  f'md<  that    the  interposition  of 

mi.   I  .'•  H.-iiliinn,  7.  I'.iio.  27.". 

.    1.  (  ,.  ii.  -I.  I!M-HIUCII.,  vol.  vn.  Nu.  o,  I'.tnl. 


THE    Z-RAY 

shoot  load  prevents  this  perception,  but  that  a  sheet  of  lead  glass  which 
will  prevent  action  upon  a  photographic  plate  will  not  prevent  a  color- 
blind person  from  noticing  a  faint  light  sensation. 

Repeated  mild  exposures  if  ;,t  short  intervals,  loss  than  a  week 
apart,  produce  a  cumulative  effect.  \o  sensation  is  experienced  at  the 
time  of  exposure.  It  may  produce  an  erythema  followed  by  brunny 
desquamat  ion  or  regular  peeling  of  the  epidermis.  This  may  be  wit  hout 
pain,  and  if  the1  applications  are  continued  for  a  good  many  weeks  or 
months  will  cause1  bron/ing  of  the  skin,  amounting  to  the  darkest  tan  that 
ever  comes  from  exposure  to  sunlight.  This  is  about  the  history  of  the 
surface  change  which  it  is  most  desirable  to  effect  in  a'-ray  treatment 
of  deep-seated  lesions.  In  superficial  malignant  disease  the  treatment 
by  repeated  mild  applications  is  sometimes  best,  and  the  visible  effect  is 
as  just  described,  with  the  addition  of  a  gradual  change  from  disease  to 
health.  One  effect  upon  the  operator  from  exposure  to  entirely  too  fro- 


Fifi.  sO-">. --Radi 

([uently  repeated  mild  doses  is  to  produce  one  of  the  lesions  described 
under  the  head  of  x- ray  dermatitis;  another  is  to  produce  sterility. 

There  is  no  immediate  systemic  effect  perceived  by  the  patient  from  ex- 
posure ot  even  t  ho  entire  surface1  of  t  he  body  to  a  >ingle  mild  application. 

Repeated  exposure1  to  mild  doses  has  the  efleci  of  impairing  the 
vitality  ot  rapidly  growing  cells.  The  embryo  may  be  killed  in  utero 
by  a  number  oi  exposures  which  art1  without  any  appreciable  effect  upon 
the  mother.  For  example,  to  watch  the  course  of  gestation  in  a  cat. 
which  had  been  the  mot  hoi1  of  several  families  of  healthy  kittens,  the 
author  took  a  number  ot  .r-ray  pictures,  beginning  before  any  evidences 
of  gestation  were  present  and  continuing  at  intervals  of  about  a  couple 


1 1  :V2 


MEDICAL    ELECTUICITY    AND    RONTGEN    RAYS 


of  weeks  down  to  a  day  or  so  before  confinement.  In  each  case  the 
author's  own  hands  rested  upon  the  cat  to  hold  her  in  position  upon  the 
photographic  plate,  and  were  as  much  exposed  to  the  .r-ray  as  was  the 
cat.  The  exposures  were1  mild  and  short.  \o  effect  was  produced 
upon  the  cat  herself  and  none  upon  the  operator's  hands  (this  was 
a  dangerous  experiment),  but  at  the  natural  time  three  mature  and 
perfectly  formed  kittens  were  born  dead.  The  exposures  to  the  .r-ray 


were  -topped,  and  the  cat  proceeded  to  have  another  family  of  four 
kittens,  which  were  born  alive  and  healthv  two  and  a  half  months  after 
the  others. 

'I 'In'  del  ails  of  the  exposures  to  which  t  his  cat  was  subjected  are  iriven 


10 
|| 

s 
'.i 
it 
Hi 


TIIK    J-KAY  1  1M 

'1'his  is  the  effect  to  he  expecteil,  and  it  is  regarded  as  undesirable 
to  make  repeated  radiographic  or  lluoroscopic  exainitiat  ions  of  the  pel- 
vis of  pregnant  women.  That  the  .r-ray  will  not  always  kill  the  fetus, 
even  when  vigorously  applied,  is  quite  certain,  and  cases  are  recorded 
in  which  .r-ray  treatment  for  cancer  of  the  uterus  has  not  interfered 
with  the  progress  and  completion  of  normal  gestation.1  Probably 
a  single  ./'-ray  examination  of  the  pelvis  would  not  affect  the  vitality 
of  the  embryo.  Repeated  applications  of  the  .r-ray  to  the  pelvic  organs 
would  be  very  apt  but  not  certain  to  do  so,  and  would  assuredly  be 
justified  in  the  treatment  of  malignant  disease.  In  the  case  referred  to 
above  the  child  was  not  killed  bv  the  .r-rav.  but  probablv  actually  owes 
its  life  to  the  .r-ray,  which  restored  the  mother  to  apparent  health  and 
enabled  her  to  go  through  gestation  and  give  birth  to  a  healthy  child. 

There  is  no  effect  upon  the  embryo  from  the  application  of  the 
.r-ray  to  other  parts  of  the  patient,  and  in  this  case  the  pelvis  should 
be  protected  from  the  rays  either  by  a  localizing  shield  about  the  tube 
or  by  tin  .r-ray  proof  covering  over  the  abdomen  and  pelvis.  This  cov- 
ering may  be  a  sheet  of  .r-ray  metal  or  of  the  soft  .r-ray  proof  rubber, 
which  contains  a  certain  percentage  of  bismuth,  baryta,  or  other  heavy 
met  allic  powder. 

Repeated  exposures  to  the  .r-ray  will  retard  the  development  of  new- 
born animals.  Tribondeau  and  Recamicr  have  verified  this  observa- 
tion in  the  case  of  a  kitten.2  The  development  of  the  eyes  was  arrested 
and  structural  anomalies  of  the  retina  were  produced.  The  develop- 
ment of  the  teeth  and  of  the  bones  of  the  face  was  much  retarded. 

Action  ofthex-Ray  {'  pou  the  Dcrelopn/cnt  oj  the  Entl»\i/o  of  tin  Clilckoi* 
—Fifteen  Holzkneeht  units  of  .r-rays  prevent  the  development  of  the 
embryo  of  the  chicken  or  arrest  its  development  if  it  is  already  com- 
menced; the  biologic  properties  of  the  albumin  are  clearly  modified  by 
the  .r-rays;  the  albumin  becomes  less  coagulable,  and  it  is  more  diffi- 
cultly digested  by  pepsin;  these  facts  may  explain  the  arrest  of  de- 
velopment of  carcinoma  treated  by  the  .r-ray. 

Effect  on  Microorganisms. —  Experiments  upon  the  effect  of  the 
.r-ray  on  microorganisms  have  been  made  by  Russ.4  Looking  at 
the  cultures  on  the  lens  of  the  microscope  itself  while  exposed  to  the 
ome  microorganisms  do  not  appear  to  be  influenced.  These  are 
s  proteus.  Vibrio  cholera1,  and  Trypanosome  Lewisii.  Others, 
acillus  typhi.  Bacillus  coli,  and  Bacillus  pyocyaneus.  show  rapid 
disordered  movements.  Kven  long  and  strong  exposures  to  the 
.r-rav  do  not  interfere  with  the  growth  or  virulence  of  different  micro- 

1.   l.evitv'  says  plant*  c.r/ioxcil  to  x-i'<i>/  suitable  for  cancer  tin1  not   in- 
jured by  it.      Plants  inoculated  with  H.  titnicfacienx  developed  crown- 
nless  .r-rayed:   then   they   did   not.      lie   found   no   evidence   that 
irritated  or  stimulated  the  tumor  u'rowth. 
Sterility    from    Rontgen    Radiation.      Repeated    mild    exposures    of 
the  < » vary  or  test  i-  are  quite  generally  regarded  as  productive  of  sterility. 
In   the  case1  of  .r-ray  operators  the  loss  ot   the  power  of  motion  in  the 

1  LaqilciTHTi1  Mini  Lalicllc.  Bulletin  <  MiiricI  <lc  la  Socictr  Francaisr  D'Klectro- 
thcrapy  H  .if  Ita.linlnii-ic.  Sept..  1'ini. 

-  (  '.  !•!.  <!<<  la  Socictr  <le  Biologic,  SS,  HW,  June  C>.  I'.tO.V 

'  Bonlirr  and  (lalinanl,  Arch.  d'Klcrt.  Med.  K\p.  et  Cliniq.,  i:;.  I'.tl.  July  in.  I'm:,. 

1  Arch,  !'.  Hyuiene.  vol.  Ivi,  p.  Mil.  1'ttiii. 

&  Aiucr.  Jour.  Kleetrntherap.  and  Hadiol.,  vol.  xxxvi,  No.  15,  March,  1'JlS,  p.  1  lii. 


1  bvl  MKDH'AL    KLKCTHICITY    AND    KONTCKX    KAYS 

spermatozoa,  and  in  some  rases  absence  of  the  spermatozoa,  has  been 
demonstrated  a  great  many  times  by  the  microscope.  The  fact  was 
first  published  by  Tilden  Brown  and  A.  T.  Osgood.  of  Xe\v  York.  This 
is  not  accompanied  by  any  sexual  impotence,  and  it  is  doubtless  not 
permanent,  but  a  condition  which  disappears  after  the  exposures  'nave 
been  discontinued  or  protect  ion  by  a  proper  apron  or  shield  has  been 
adopted.  1  his  necrosperniia  mav  develop  in  anyone  who  spends  much 
time  in  an  .r-ray  room  where  no  precautions  are  taken  to  limit  the  rays 
to  sonic  one  particular  direction. 

The  effect  upon  the  testicle  from  repeated  moderately  severe  applica- 
tions of  the  ./--ray  has  been  studied  by  Bergonie  and  Tribondcau.1 
Six  while  rats  were  used,  and  entirely  protected  by  sheet  lead  except 
where1  the  testicles  were  exposed.  Rat  one,  five  applications  of  2 
Holzknecht  units  at  intervals  of  eight  days;  rat  two,  nine  applications 
of  1  H.  at  intervals  of  two  days;  rat  three,  eleven  applications  of  2  H. 
at  intervals  of  two  days;  rat  four,  ten  applications  of  4  II.  at  intervals 
of  two  days.  These  rats  had  all  had  one  testis  removed  before  the 
experiment.  The  one  exposed  was  removed  and  examined  a  month  and 
a  half  after  the  last  exposure.  Rat  five,  both  testes  exposed  five  times 
to  4  H.  at  intervals  of  eight  days,  one  testis  removed  immediately  after 
the  last  seance,  the  other  a  month  and  a  half  later. 

The  result  was  the  same  in  all.  There  was  no  change  in  the  skin  or 
hair,  but  there  was  a  great  change  in  the  testis,  consisting  in  the  substi- 
tution of  a  serous  liquid  for  the  peripheral  parenchyma,  the  same  liquid 
separating  the  deep  parenehymatous  tubules,  and  a  breaking  down  of 
the  epididymis. 

A  male  cat  may  be  sterilized  by  .r-rays  filtered  through  2  mm.  of 
aluminum  and  with  a  dose  of  about  4  Bordier  applied  in  one  or  two 
seances.  The  oviform  cells  survive,  but  disappear  sooner  or  later. 

The  same  authors  have  measured  the  dose  required  to  completely  and 
permanently  sterilize  a  male  dog.-  and  in  the  latter  case  have1  shown  that 
the  refractory  oviform  cells  are  incapable  of  regenerating  epithelium. 

The  histologic  changes  are  found,  in  the  seminal  epithelium  of  the 
testis,  which  is  the  source  of  the  spermatozoa,  and  not  in  the  interstitial 
glandular  tissue,  whose  activity  is  the  cause  of  the  sexual  instinct  and 
sexual  activity.  The  secretion  from  the  interstitial  gland  is  an  "inter- 
n;il  "  one.  and  is  concerned  with  the  maintenance  of  all  the  masculine 
characteristic.-!  of  the  general  system.3 

Observations  on  animals  show  thai  repeated  mild  exposure  of  the 
pelvic  region  results  in  the  ovaries  ceasing  to  produce  Graah'an  iollides. 
Thi-  effect  i-  probably  temporary. 

Two  hundred   minutes'  exposure  of  one  ovarian   region  of  a  rabbit 
•  lie  ot  her  ovarv  was  shielded  produced  very  marked  atrophy  ot  t  lie 
,..        •     ;md     disappearance  of     the     (iraafian     follicles.       I  lalberstadtcr 
iio-ure  iii  t  went  v  davs  in  divided  doses,  and  found  t  he  ovary 
;j/e  of  I  he  one  m  it  exposed. 

Return     of     Spermatogenesis    After     .r-Ray    Exposures.— The 

iiow-    of   c;ise-    in    which    physicians    working    much    with    the 

.    •.     ;  roteclion   have  been   luiind    to   have  complete 

i'l  :   ,-ricit.1  \I'-i:<':tl.'.  Bordeaux,  Krmri',  l-Vh.  2."i,   I'.Hir,. 

(   .  I!  ,  :    i      l: .  .!••  !;i  Sue.  .',.-  Bi.,1 ..  l\\.  :..  .l.-ni.  7.  I'.M  1.  :nnl  1\\, 
f>n.  .! 

\    v .  ••                     •  -   :   ' •••  -.  l';iris,  vol.  f\lii.  |>    ,  _':;. 

'      \     •      ;•  .        !_'.      I',   1.      .hll.       |li,       I'.HI.Y 


THK    r-HAY  1135 

necrospcrmia  and  apparent  azoosperrnia,  and  in  whom  a  vacation, 
and  tlie  subsequent  use  of  a  heavy  apron  of  rubber  loaded  witli  baryta, 
and  an  efficient  shield  around  the  .r-ray  tube,  have  been  followed  by 
the  reappearance  of  living  spermatozoa,  and  the  men  have  had  children. 

Laquerriere1  re])orts  a  similar  case,  in  which  the  return  of  sperma- 
tozoa was  followed  by  conception. 

A  patient  of  Dr.  Lapowski's-  was  a  man  with  pruritus  scroti,  who 
was  treated  by  the  r-ray.  Previous  microscopic  appearances  were  nor- 
mal, but  after  two  applications  of  ten  or  fifteen  minutes,  at  a  distance 
of  15  cm.,  there  was  necrospermia.  The  treatment  was  repeated  twenty 
days  later,  and  after  that  There  was  azoospcrmia.  Five  months  later, 
however,  living  spennato/oa  were  present. 

Phillips'  cases,  purposely  sterilized,  were  found  to  be  still  so  six 
mon) hs  later. 

A'-ray  workers  who  have  found  that  they  were  sterile  have  kept  out 
of  the  .r-ray  room  altogether,  and  have  after  a  year  or  two  had  children, 
and  then  have  resumed  r-ray  work  and  have  had  no  more  children. 
(  Mliers  have  found  no  living  spennato/oa,  in  fact  no  discoverable  sperma- 
tozoa at  all,  and  after  a  couple  of  months'  complete  absence  from  x-ray 
exposure,  followed  by  the  use  of  an  opaque  apron  and  of  a  shield  to 
envelope  the  tube1,  have  found  living'  spermatozoa  again. 

Absence  of  Effect  on  Spermatozoa  Outside  the  Body. — Human 
spermatozoa,  after  leaving  the  body,  are  not  greatly  influenced  by  the 
.r-ray.  Their  vitality,  according  to  Bergonie  and  Tribondeau,3  is  not 
modified  by  an  exposure  of  half  an  hour,  at  a  distance  of  15  cm.  from 
the  anticathode. 

Precautions  to  be  Taken. — When  repeated  applications  of  the 
.r-ray  are  required  the  ovaries  or  testes  should,  therefore,  always  be 
protected  from  the  .r-ray. 

Baldness. — Repeated  mild  exposures  result  in  thinning  or  loss  of 
the  hair.  This  is  only  temporary,  but  should  be  guarded  against. 

Toxemia. — In  a  number  of  cases  which  have  been  reported,  and  the 
author  is  sure  that  many  others  have  not  yet  been  reported,  and  some 
have  not  been  recognized  as  attributable  to  the  ,r-ray,  a  single  thera- 
peutic or  diagnostic  application  of  the  r-ray  has  been  followed  by 
seven1  constitutional  disturbance.  The  author  has  seen  this  occur  after 
the  first  mild  application  for  cancer  of  the  breast,  and  it  has  been 
noted  in  leukemia  and  other  conditions  in  which  applications  are  made 
with  a  view  to  an  effect  upon  a  constitutional  disorder. 

I  Msall's  observations* upon  cases  of  leukemia,  unresolved  pneumonia, 
pernicious  anemia,  and  gout  treated  by  the  r-ray  show  that  when  a 
single  application  produces  an  immediate  marked  effect,  beneficial  or 
otherwise,  the  examination  of  the  urine  and  other  means  of  stud}" 
usually  show  that  destructive  metabolism  has  been,  for  the  time  being, 
enormously  increased.  Some  of  these  patients  were  on  a  regular  diet 
containing  a  measured  amount  of  nitrogen,  and  the  amount  of  nitrogen 
excreted  had  been  watched  for  a  few  davs  before  the  .r-ray  was  applied. 

In  some  cases  the  excretion  of  nitrogen  during  the  next  twenty-four 
hours  was  almost  doubled.  These  cases  with  increased  excretion 


'  t.  '<  iniiiv-'s  of  the  French  Association  for  the  Ailv:inc 
on  Medial  I-:i.-ctri"ity,  Lyons,  Auu;.,  190*1. 

-  Bnnvn  ait'l  <>>u;<i<>d's  Article.  Am.  .lour.  Surgery,  19U.~>.  Xo.  0. 

;i  ('.  !!.  de  la  Socirte  do  Bio!oLn.',  57,  /W.">.   Dec.  ii.   I'.HH. 

4  University  <>f   Pennsylvania   Medical    Bulletin,   Sept.,    190.~>;  Jour.  Am.    Mi 
Assoc.,  Xov.  :;.'  I'.tOti. 


Hot)  MKDH  AL    KI.KlTKIClTY    AM)    KONTCKN     HAYS 

included  patients  with  leukemia  or  with  unresolved  lobar  pneumonia, 
and  were  favorably  influenced  by  the  .r-ray  applications.  The  increased 
metabolism  may  be  due  to  an  effect  upon  the  tissue  ferments. 

The  cases  without  an  increase'  in  nitrogenous  excretion  were  unfavor- 
ably influenced,  and  some  were  apparently  even  killed  by  the  .r-ray 
application.  It  seem.-  from  the'  studies  already  alluded  to,  and  also 
from  those  of  Kdsall  and  Pemberton,1  and  of  Musser  and  Kdsall.-  that 
these-  we're  case's  in  which  the-  large  breaking  down  of  nitrogenous  tissue 
-ub-tances  was  too  much  of  a  tax  for  the  eliminative  organs,  and  that 
the  latter  were  overwhelmed  and  partly  incapacitated  by  the  unusual 
demand  upon  them.  'Ihe  result  in  some  cases  was  a  toxemia  caused 
bv  the  excess  of  broke-n-down  products  in  the  system. 

According  to  these  authors,  the-  application  of  the  .r-ray  to  any 
considerable  portion  of  the  beidy,  especially  if  the  hematopoietic  organ-, 
such  as  the  spleen  and  the  marrow  of  the  long  bone-s  are  exposed, 
ivgularlv  produces  a  tremendous  increase  in  the-  destructive  meta- 
morphosis of  nitrogenous  tissue  substances,  such  as  mu'leoprotein,  and 
this  calls  for  increased  activity  of  the  eliminativc  functions.  The  effect 
under  consideration  is  not  that  of  a  large'  and  toxic  dose;  of  the  .r-ray, 
but  that  of  a  single'  therapeutic  or  diagnostic  application,  which  under 
ordinary  circumstances  produces  no  apparent  symptoms.  Kdsall  says 
that  he  knows  of  no  drug  or  other  therapeutic  agent  which  produces  an 
equal  effect  in  ordinary  dosage. 

The  cases  in  which  this  increased  tissue  destruction  is  liable  to 
produce  a  harmful  effect  are  those  in  which  the  patient  is  already  in 
a  toxemic  condition,  or  in  which  there  is  nephritis  or  some  similar  dis- 
ease which  interferes  with  the  elimination  of  waste  products. 

\o  constitutional  effect  results  from  such  an  application  of  the' 
.r-ray  as  is  required  for  treat  ing  an  epithelioma  of  the  face',  or  for  making 
a  radiograph  of  the  hand,  if  the  rest  of  the  body  is  shielded  from  the  rays. 
Hut  when  the  body  is  not  shielded,  even  though  one  of  the-  extremities 
may  be  nearer  the  .r-ray  tube,  and  consequently  receive  a  stronger 
exposure,  a  constitutional  effect  is  produced.  This  is  also  the  case1 
when  the  .r-ray  has  to  shine  through  a  large  part  of  the'  chest  or  ab- 
domen tor  examination  or  treatment. 

Harmful  constitutional  effects  may  be  avoided,  whether  the  patient 
is  in  a  favorable  condition  or  not,  by  shielding  all  but  the  portion  of  the 
patient  which  it  is  desired  to  examine  or  treat  when  this  is  a  small  and 
not  a  vital  part;  also  by  making  sure  that  the  patient  is  in  a  healthy 
condition  ">  cases  where  a  more  general  expo.-ure  or  one  involving  the 
•-'  or  abdomen  is  required.  Such  applications  to  a  patient  suffering 

i    the    tovniia    of    cancer,    pernicious    anemia,    leukemia,    or    other 

ilar  disease,  or  with  elimination  crippled,  as  m  cases  of  nephritis, 
-hould  generally  be  avoided,  but  il  necessary  .-hould  be  cautiously  made. 

I  he  effect   which  is  under  consideration  has  not   usually  the  cumula- 
iracter  shown  bv  the  effect  upon  the  -km  and  some  other  < irirans. 
!  iiil    ary,  a  -ingle  mild   general   application   may  be  followed  bv 

:."-'    profound  constitutional   effect,  while  a   number  of  similar  ap- 
'•  "li   -ucces.-ive  (lavs   may  not    produc*1  any  change  in   the  ap- 


i'  effects  of   a  single   severe   application  are   not    perceptible  at 
the  ;  ime,  b  n  develop  after  one  to  seven  da  vs.     'I  hey  a  re  clueflv  upon  the 

V,    Jour.  Me, |.  Sciences.  I  'ebruary  ;m«l  March.  I'.mT. 
*  I  nivt T-ity  of  Pennsylvania  Medical  Bulletin,  September,   l'.H),">. 


superficial  tissues,  and  vary  all  the  way  from  a  slight  erythema  to  a 
destruction  of  tissue  ri<;ht  down  to  periosteum,  which  may  lake  months 
to  heal  or  which  may  never  do  so.  The  lesser  decree  is  often  required 
m  the  treatment  of  disease  and  is  not  accompanied  by  visceral  changes. 
The  very  greatest  decree  has  onlv  been  produced  in  observations  on 
animals  —  alonu'  the  spine  it  has  resulted  in  men  in  ^it  is  and  death:  over 
the  abdomen  even  the  greatest  decree  of  overexpnsure  has  not  produced 
^TOSS  changes  in  the  Castro-intestinal  tract.  Enough  has  been  said  to  show 
that  the  effect  of  a  single  very  excessive  exposure;  is  so  disastrous  that 
the  ./--ray  should  never  be  applied  at  all  by  one  unfamiliar  with  its  dos- 
age. All  the  elements  which  ,uo  to  make  up  a  knowledge  of  the  correct 
do.-e  and  the  way  to  apply  it,  either  for  diagnosis  or  treatment,  are  of 
the  verv  greatest  importance.  Repeated  severe  applications  have  a 
cumulative  effect  if  u'iven  at  intervals  of  less  than  one  or  two  or  three 
weeks.  The  least  severe  application  which  will  produce  a  visible  effect 
upon  the  skin  of  the  face  is  about  o  1  lolxknecht  units  (o  11.),  and  this 
may  be  repeated  every  three  weeks  without  doin.u'  more  than  maintain 
a  sliji'hl  reaction.  If  this  dose  is  ^iven  more  frequently,  or  if  a  larger 
dose  is  li'iven  at  the  same  interval,  an  increased  effect  is  noted  from  each 
application..  Another  fact  of  importance  is  t  hat  a  surface  which  has  once 
shown  a  reaction  to  the  .r-ray  is  more  susceptible  for  a  ]on,ir  time  after- 
ward. 

Experiments  reported  by  I  leinecke.  of  Leipzig,  al  the  (ierman  Medical 
Congress  of  I'.tOl.  show  the  effect  of  prolonged  exposure  to  intense  radia- 
tion. His  studies  were  especially  upon  the  lienuitopoietic  organs,  and 
the  animals  were  exposed  to  the  x-ray  for  ten  or  fifteen  hours  at  a 
stretch.  In  the  marrow  of  the  lonir  bones  there  was  almost  a  complete 
disappearance  of  the  characteristic  lymphocytes,  only  red  cells  beintr 
present.  Xo  <:TOSS  lesions  were  present  if  the  animal  was  killed  imme- 
diately after  the  irradiation,  but  at  the  end  of  a  week  they  were  always 
found.  In  the  first  four  hours  after  irradiation,  in  do^s.  a  microscopic 
change  was  noted  in  all  the  lymphatic  oriran.-.  the  spleen,  the  intestinal 
follicle.-,  the  lymphatic  glands:  this  change  consisted  in  a  destruction 
of  lymphocytes  and  their  absorption  by  phagocytes.  This  abnormal 
condition  had  disappeared  at  the  end  of  twenty-four  hours.  1  he 
temperature  may  be  elevated,  and  the  do<_r  may  lose  as  much  as  one- 
four!  ii  of  his  entire  weight  in  twenty-four  hours,  '1  he  Malpi<i"hian 
corpuscles  of  t  he  spleen  almost  disappear  and  are  replaced  by  connective 
tissue.  lie  found  that  a  similar  effect  was  produced  upon  sarcoma, 
but  only  upon  the  small  round-celled  tvpe. 

Exposure  Necessary  to  Produce  Physiologic  Effects. — The 
constitutional  effect  which  is  sometime-  seen  immediately  after  a 
treatment  tor  cancer  or  leukemia,  and  which  seems  to  be  due  to  an 
increased  metabolism,  may  be  occasioned  bv  an  exposure  ot  twelve 
seconds  to  the  mo.-t  powerful  radiance  m  making  an  .r-ray  examination, 
or  of  live  minutes  to  the  milder  radiance  ordinarily  employed  in  radio- 
therapv.  The  changes  in  the  tissues  of  the  spleen,  lymphatics,  and 
marrow,  noted  in  the  experiments  on  mice,  rabbits,  do^s.  and  other 
small  animal.-,  required  verv  much  longer  exposures. 

Krau-e  and  Zie^ler  u.-ed  a  u'0-centimeter  or  iM-inch  induct  ion-coil, 
with  a  \\ehnelt  interrupter  connected  \\ith  the  1  10-voh  direct  electric 
liii'ht  iiiii  circuil  the  pnmarv  current  bemv;  I  or  •">  amperes.  1  he  dis- 
tance iVoin  the  animal  was  '_'()  to  10  cm.  >s  to  1(1  in.),  and  the  duration 


1.5iS  MKDKAL    KLKt  THHITY    AND     RoNTdKN     HAYS 

of  exposure  in  mice  was  from  two  to  ten  hours.  Mice,  which  were 
exposed  four  hours  or  longer,  died  in  a  few  days  as  a  consequence  of 
the  destructive  effect  upon  the  blood-forming  elements  in  the  spleen, 
the  lymphatics,  and  the  marrow  of  the  long  bones.  An  important  fact 
i-  that  the  fatal  effect  was  produced  whether  the  exposure  was  a  con- 
tinuous one  or  was  divided  up  into  several  exposures  of  fifteen  or  thirty 
minutes  each.  Kven  as  short  an  exposure  as  fifteen  minutes,  while  not 
producing  fatal  or  even  serious  effects  upon  the  animal,  caused  necrotic 
foci  in  the  spleen,  which  could  be  found  if  the  animal  were  killed  soon 
after  the  exposure,  but  which  were1  almost  normal  again  if  the  animal 
was  not  killed  until  eleven  days  later. 

Krause  and  Xiegler  exposed  guinea-pigs  for  ten  hours  with  similar 
temporary  effects  upon  the  blood-forming  organ.-,  but  without  a  fatal 
effect.  The  same  ten-hour  exposures  produced  similar  results  in  dogs. 

Sterility  in  men  appears  from  Phillip's  cases  to  1»>  produced  by  an 
exposure  of  one  hundred  to  two  hundred  minutes  to  a  ray  of  moderate 
intensity,  but  as  this  was  enough  to  produce  excoriation  of  the  scrotum, 
divided  shorter  exposures,  distributed  over  a  number  of  weeks,  could 
produce  this  effect  upon  reproduction  without  the  effect  upon  the  skin. 
Occasional  microscopic  examinations  would  show  when  necrospermia 
or  a/oospermia  had  been  produced. 

The  exposure  required  to  produce  falling  of  the  hair  is  susceptible 
of  quite  exact  measurement,  as  explained  under  the  head  of  .r-ray 
dosage  in  the  chapter  on  Radiotherapy.  The  effect  is  produced  either 
by  a  single  exposure,  amounting  to  from  4  to  7  Hol/knecht  units,  or 
by  several  exposures  aggregating  the  same  amount.  Workers  with  the 
.r-ray  should  have  the  ./'-ray  tube  enveloped  in  a  box  made  of  material 
opaque  to  the  .r-ray  except  in  the  direction  in  which  the  latter  is  to  be 
applied,  and  in  using  the  fluoroscope  should  have  the  fluorescent  surface 
covered  bv  lead  glass.  The  latter  protects  the  eves  also.  .  A  cap 
lined  with  sheet  lead  affords  very  good  protection  for  the  operator's 
hair.  An  apron  made  of  sheet  rubber  containing  a  large  percentage 
of  baryta  protects  the  body  and  genitals,  (iloves  containing  baryta  or 
lead  oxid  protect  t  lie  haiii  Is. 

Kienbock  observed  that  mice  which  were  exposed  for  several  hours 
to  the  .r-ray  applied  over  the  back,  developed  severe  nervous  svrnp- 
toms  in  about  three  days.  The  eyes  were  closed,  the  spinal  column 
flexed,  and  there  was  spastic  paralysis  of  the  limbs.  The  mice  died. 
Similar  exposures,  t  hough  -t  rong  enough  to  cause  the  hair  to  fall  out  and 
to  produce  dermatitis,  did  not  cause  symptoms  of  disturbance  of  any 
internal  organ  m  guinea-pigs  and  rabbits. 

<M    course,  in  the  smallest    animals    the    spinal    cord    is    covered    by 
;i   thin  delicate  layer  of  bone  and  soft    parts  as  to  be  very  directly 
e  . :  ose-d  to  the  ray.-. 

I1,    larger   animal-   a    thicker   layer  of   -oft    tissues   and    thicker   and 
•     (tones    absorb    a    larger    part    of    the    .r-rav    and    present    greater 
pro1  n  for  t  he  -[  >inal  con  I. 

•   cposed  a  pigeon  to  the  ./'-ray    and  ob.-erved  falling  out  of 
\'~.   not    onlv  on   the  .-ide  toward   the  ./'-ray  tube  but   al-o  on 
.    from    the   tube.      The   latter   was   apparently   caused   bv 
ray-  i  traversed   the  entire  thickne--  of  the  abdomen  without 

• '  'ft   upon  the  mt  ernal  orga  us. 

The  Effect  of  the  .r-Ray  Upon  the  Eye.     Tin's  | 


1139 

lively  studied  by  Rirch-Ilirschfeld.1  He  has  not  found  any  change' 
in  the  retina  except  in  cases  where  the  exposure  has  been  severe  enough 
to  produce  clinical  changes  in  the  eye. 

An  exposure  of  10  or  'JO  II..  however,  produces  changes  which  may 
attect  clueflv  the  anterior  or  the  posterior  structures  of  the  eye  in 
different  cases.  There  is  a  period  of  incubation  lasting  from  fifteen  to 
forty-one  days.  There  is  a  characteristic  effect  upon  the  epithelial 
cells  of  different  parts  of  the  eye.  Those  of  the  cornea  become  irregular 
and  swollen  and  their  nuclei  become  flattened  out  and  sometimes  divided. 
There  are  also  some  degenerated  and  vacuoli/ed  cells.  The  conical 
e[)it  helium  mav  be  desquamated  until  onlv  a  single  layer  remains,  and 
may  then  be  gradually  replaced. 

The  eyelashes  fall  out . 

These  are  the  changes  in  the  inner  walls  of  the  blood-vessels  detailed 
in  the  general  description  of  the  physiologic  effects  of  the  .r-ray. 

The  iris  undergoes  swelling  and  loosening  of  its  epithelial  cells  and 
degeneration  of  the  pigmented  cells  in  its  stroma. 

The  crystalline  lens  and  its  epithelial  cells  are  unaffected.  The 
effect  upon  the  retina  and  optic  nerve  becomes  visible  at  the  end  of  sev- 
eral weeks.  The  ophthalmoscope  reveals  atrophy  of  the  optic  papilla. 
The  microscope  confirms  this,  and  also  shows  degeneration  of  the  gan- 
glionic cells  of  the  retina,  with  vacuolization  and  a  characteristic  change 
in  t  heir  ehromatin.  This  coloring-matter  does  not  disappear  as  its  does 
from  the  effect  of  the  ultraviolet  ray,  but  divides  up  into  numerous 
small  particles.  It  becomes  "pulverized."  There  is  degeneration  of 
the  optic  nerve-fibers,  which  Birch-Hirschfeld  considers  secondary  to 
the  degeneration  of  the  ganglionic  cells,  and  not  due  to  a  direct  effect 
of  the  .r-ray  on  the  nerve-fibers. 

An  <  >/c  irhifh  )x  exposed  to  the  .T-rni/  in  the  course  of  tJie  trcatint  nt 
of  a  cancer  of  the  e>/eli(l  gradually  becomes  affected,  although  the 
sight  ma}'  not  be  destroyed  for  many  months.  The  eye  begins  to  look 
smaller,  the  conjunctiva  reddens,  and  the  cornea  becomes  opaque,  not 
whitish,  but  because  it  is  covered  by  newly  formed  connective  tissue. 
This  tissue  contains  blood-vessels  and  round  cells  and  is  covered  by 
several  layers  of  epithelium  of  a  character  similar  to  that  of  the  skin. 

The  //•/'*  is  infiltrated  by  leukocytes;  most  of  tin'  pigmented  cells 
disappear;  the  walls  of  its  blood-vessels  undergo  the  usual  effect  from 
the  .r-ray. 

The  retina-  shows  the  usual  r-ray  degeneration  of  the  ganglionic  cells 
and  of  the  intima  of  the  blood-vessels.  No  change  is  to  be  discovered 
in  the  optic  nerve-fibers.  There  is  a  very  marked  change  in  and  near 
the  macula  lutea.  Cysts  develop  which  thrust  aside  the  internal  gran- 
ular layer.  There  are  spaces  of  almost  normal  retina  between  these 
circumscribed  cysts. 

The  eye  is  permanently  destroyed. 

This  effect  may  be  guarded  against  by  usini:  sonic  kind  of  shield 
protecting  the  whole  orbit,  or.  if  the  evehds  are  to  be  treated,  the 
eveball  may  lie  protected  by  an  opaque  s 
and  under  the  eyelids.  The  model,  shown 
and  ha>  a  ]  >r>  tject  i<  n\  on  its  ext  erna  1 
M-rt  inu'  and  removing  n  . 


11-10 


MEDICAL    KI.KCTKUITY    AM)    ROXTCJEX     KAY: 


about  the  eye  be  limited  to  malignant  and  tubercular  disease  of  the 
eyelids,  and  that  not  more  than  S  or  10  H.  should  he  applied  once  in 
two  \veeks. 

These  conclusion-  should  probably  he  modified.  The  dosage  seems 
unnece-sarily  and.  then-fore,  undesirably  lariie,  and  the  x-ray  has  been 
used  safely  and  with  excellent  results  in  trachoma. 

Effect  of  the  ,/r-Ray  Upon  the  Liver. — Experiments  by  TTudellet1 
.-how  that  in  the  adult  rabbit  it  causes  only  some  interference  with 
intercellular  nutrition  in  the  liver.  In  a  voting  rabbit  it  causes  a  certain 
derive  of  atrophy  without  necrosis.  The  liver  of  a  newborn  kitten 
undergoes  changes  amounting  to  destruction  of  the  part  of  the  liver 
directly  exposed  to  the  rays.  Each  exposure  was  usually  the  same 
except  as  to  duration.  A  D'Arsonval-(  iail'fe  transformer  was  used  with 
1  ma.  of  secondary  current  and  Xo.  7  Kenoist  rays,  the  distance  from 
tin1  ant  icat  hodc  to  the  skin  being  l.~>  mm.  The  exposures  in  two  adult 
rabbits  were  one  hour  and  two  hours  respectively.  The  young  rabbits 
were  exposed  over  the  region  of  the  liver  foi  about  ten  minutes  every 
day  for  twenty  day.-.  A  newborn  kitten  received  exposures  of  ten 
minutes  every  other  day  from  the  third  to  the'  twenty-first  da)'  after 
birth. 


Effect  Upon  the  Nervous  System.-  Scorbo.  of  \aplc-.  has  noted  a 
neui1"":  i-ciilar  tr.iphic  action  of  the  r-rav. 

>'  '.  ej-al  author-,  including  Schaiv  have  reported  the  occurrence  of 
IH-rvo  .  -  i  -t  MI  1 1 a  lice-  alter  expo- urc  to  t  he  .r-i'a  y,  but  I  he  li'n-a  i  ma  jorit  v 
i'f-  have  never  ob-erved  anything  of  the  kind  in  their 
pat  lent 


THE    X-RAY  1111 

The  case  reported  by  ( 'olombo'  of  severe  nervous  crises  following 
therapeutic  applications  of  the  x-ray  to  the  leg  may  possibly,  in  the 
light  of  Kdsall's  observations,  be  attributed  to  a  toxemia  instead  of  to 
a  direct  effect  upon  the  nervous  system. 

Intense  radiation  of  the  brain  in  some  of  Kodet  and  Hertin's'-'  expeiv 
ments  caused  paralysis  and  convulsions  and  the  postmortem  appearance 
of  meningomyelitis. 

Tarkhanol'P  also  reported  a  diminution  of  reflexes  in  a  frog  in  which 
the  brain  was  irradiated. 

Later  observations,  especially  those  of  Krause  and  Ziegler,1  seem 
to  show  that  when  the  whole  animal  is  exposed  no  effect  is  produced  upon 
the  brain  or  spinal  cord,  and  the  same  mav  be  the  case  when  onlv  the 
nervous  centers  are  exposed. 

The  Effect  on  the  Intestines. — The  follicles  of  the  intestinal  wall 
are  among  the  tissues  which  are  especially  susceptible  to  the  influence 
of  t  he  ./--ray.  After  ten  hours'  irradiation  of  the  entire  animal  in  Krause 
and  Xiegler's  experiments  (/.  r.)  intestinal  follicles  were  found  imme- 
diatelv  afterward  to  show  necrotic  foci,  but  these  had  disappeared  if  the 
animal  was  not  killed  until  four  days  later,  and  a  clear  area,  consisting 
partlv  of  epithelioid  cells,  was  found  at  the  center  of  each  follicle.  The 
effect  on  the  intestines  is  really  part  of  the  effect  on  lymphatic  tissue, 
•which  occurs  wherever  this  is  to  be  found. 

The  eff'-ct  on  the  skin  is  a  breaking  down  of  the  hair  follicles,  edema, 
and  disintegration  of  the  epidermic  cells,  hyperkeratosis,  and  necrotic 
disintegration  of  the  epithelium,  inflammatory  exudation  into  the 
corium,  and  thickening  of  the  intima  of  the  large  vessels  in  the  skin. 
JK rd uxc  find  Zict/lcr  found  no  cfmnycs  in  the  liver,  ])dncrcdx,  the  mneoux 
<n'  xdlirdnj  yldndx,  the  thi/roid  (jldnd,  or  the  kidneys. 

Effects  Upon  the  Kidney. — As  has  just  been  stated,  the  latest 
•tnd  most  complete  series  of  experiments  leads  to  the  conclusion  that  the 
kidneys  undergo  no  change  referable  to  the  direct  action  of  the  .r-ray. 
Cases  of  nephritis,  sometimes  occurring  in  experiments,  were  considered 
a.-  due  to  the  anesthetic.  (Dogs,  especially,  had  to  be  kept  quiet  in 
this  wav  long  enough  for  the  exposure,  which,  however,  is  entirely 
\vithout  sensation.) 

Kdsall's  observations  make  it  seem  probable  that  cases  of  nephritis 
after  x-ray  exposure  are  due  to  the  increased  metabolism  occasioned  by 
t  he  exposure. 

A  recent  report  of  a  case  of  nephritis  cured  by  applications  of  the 
r-ray  to  the  kidnev  is  not  at  all  negatived  by  our  knowledge1  of  the  effect 
of  t  he  x-ray  upon  t  hat  organ. 

Wart  hin's  observations  upon  the  effect  of  the  x-ray  upon  the  kidney 
show  thai  the  direct  effect  is  very  slight,  even  when  animals  are  exposed 
to  very  long  applications.  The  indirect  effect  is  proportional  to  the 
destruction  of  leukocytes  and  the  exaggeration  of  uric  acid  excretion. 
and  is  mo-t  marked  in  leukemia.  In  some  cases  of  the  latter  disease 
after  x-ray  treatments  he  has  found  the  kidneys  sclerotic,  and  with 
calcareous  depo.-its  and  faltv  degeneration  of  certain  tubules,  while. 
other-  showed  pre-.-ure  necrosis. 


1112  MEDICAL    ELECTRICITY    AND    KONTGEN    KAYS 

Effect  Upon  the  Blood.—  There  is  a  direct  effect  upon  the  white 
Mood-cells.  Their  number  is  at  first  reduced  and  then  there  follows 
a  very  temporary  leukocytosis.  There  is  an  increase  in  the  amount  of 
hemoglobin  and  in  the  specific  gravity  of  the  blood  without  an  in- 
crease in  the  number  of  red  blood-cells.  In  the  smallest  animals  the 
mature  red  blood-cells  appear  to  be  produced  faster  than  normal  by  the 
loss  of  nuclei  in  the  cells  of  which  they  are  the  mature  form.  This, 
while  a  natural  process,  is  still  a  degenerative  one.  and  that  it  is  acceler- 
ated by  the  r-ray  is  in  line  with  all  the  rest  that  we  know  about  the 
properties  of  the  latter.  For  instance,  the  hyperkeratosis  which  is  a 
characteristic  effect  upon  the  skin  is  an  exaggeration  of  the  normal 
degeneration  through  which  epithelial  cells  pass. 

EI'I'IC!  ('/x»i  tin  Hl/iod  in  Vitro.  —  Helber  and  Linser1  have  tested  the 
effect  of  the  .r-ray  upon  blood  in  a  test-tube.  They  find  that  a  leuko- 
toxin  is  developed  in  the  serum  which  destroys  i  he  white  blood-cells 
Blood--ennn  from  a  patient  with  leukemia  ordinarily  produces  nC 
effect  if  injected  into  a  rabbit,  but  it  produces  a  marked  effect  if  the 
patient  from  whom  the  serum  is  obtained  has  been  under  .r-ray  treat- 
ment. In  this  case  an  examination  of  the  rabbit's  blood  four  hours 
later  shows  a  considerable  reduction  in  the  number  of  white  cells. 

Heinecke's  Experiments1'  on  the  Effect  of  the  ./'-Ray  Upon  the 
Marrow  of  the  Long  Bones.  —  The  destruction  of  white'  blood-cells 
in  the  bone-marrow,  which  takes  place  after  several  hours'  exposure 
of  the  entire  body  of  a  guinea-pig,  begins  about  two  and  a  half  hours 
after  the  commencement  of  the  exposure.  It  reaches  its  maximum 
in  ten  or  twelve  hours  and  ''eases  after  five  or  six  days.  All  the  different 
form-  of  leukocytes  in  tin  marrow  are  reduced  in  number,  but  the  lym- 
phocytes and  non-granular  myelocytes  are  the  most  affected;  the  eosino- 
phile.  mast  cells,  and  giant  cells  are  somewhat  less  affected,  while 
the  neutrophile  polymorphic  granular  cells  remain  intact  the  longest. 
1  he  broken-down  marrow  is  capable  of  regeneration,  and  this  begins  at 
the  end  of  about  two  weeks  and  is  completed  in  three  or  four  weeks. 

Ileinecke's  observations  go  to  show  that  in  man  the  bone-marrow 
may  read  to  the  ./--ray.  but  that  undesirable1  or  dangerous  complications 
from  the  destruction  of  lymphocytes  do  not  take  place. 

Changes  in  the  Spleen.  —  The  immediate  chanties  in  the  spleen  are 

unmatory    hyperemia    and    an    increased    collection    ot    leukocytes, 
takes    place  at    the  center  of  each   follicle   in    the   spleen.      There 


pleen  may  break  down 


of  a  rapii  IK'  proliferatin 


gs  the  secondary 
General    Histologic    Changes.     <  leneral 

•  r-ra  v  is  to  proi  luce  an  obht  erat  iv 

-  an>  1  a  '  le-t  rud  ive  effect  upon  cell 

,-e. 


V  RAY   BURNS   OR   RONTGEN   DERMATITIS 

1  1  1     '  ;  ,-     r-ra  v    |  >r<  «  luces   a    cha  Hire    in    the 


THE    X-RAY  1  143 

fatal  results.  The  danger  is  all  the  greater  beeause  there  is  no  sensation 
of  warmth  or  discomfort  at  the  time.  It  may  be  produced  by  a  single 
•  overexposure,  the  irradiation  being  too  powerful,  or  too  long  continued, 
or  the  tube  being  too  near  the  surface.  The  various  instruments  of 
precision  for  measuring  the  strength  and  quality  of  the  x-ray  are  as 
necessary  to  proper  dosage  in  examination  and  treatment  as  they  are 
to  successful  picture  making.  The  cumulative  effect  of  successive  ex- 
posures to  the  x-ray  is  a  source  of  danger,  especially  to  the  operator, 
and  very  many  of  the  x-ray  specialists  in  this  country  have  hands  which 
are  disfigured  by  chronic  dermatitis.  In  the  worst  case  the  author  over 
saw  the  patient  made  and  sold  x-ray  apparatus  during  the  first  year 
after  its  discover}",  and  was  probably  looking  at  or  allowing  others  to 
look  at  the  bones  in  his  hand  a  large  part  of  the  time.  The  apparatus 
in  those  days  produced  a  comparatively  feeble  radiance,  so  that  no 
immediate  effect  was  noted,  but  after  several  weeks  of  this  reckless 
exposure  he  suddenly  developed  an  inflammation  and  gangrene  of  the 
back  of  the  hand  and  wrist.  After  several  months  of  severe  suffering 
the  slough  all  came  away  leaving  the  tendons  and  the  articular  carti- 
lages bare.  Healing  with  deformity  finally  took  place.  Of  a  similar 
nature  at  the  start  were  the  recorded  cases  which  years  later  formed 
the  starting-point  for  epithelioma;  and  amputation  and  in  some  cases 
even  death  have  followed. 

There  is  nothing  to  indicate  that  an  x-ray  burn  is  an}'  more  likely  to 
be  followed  by  cancer  than  any  other  lesion  of  similar  severity  and  ehron- 
icity. 

Rontgen  dermatitis  may  be  of  four  different  degrees: 

(1)  A  mild  temporary  redness  of  the  skin  occurs  without  anatomic 
changes;  it  may  not  develop  until  two  weeks  after  exposure  and  lasts 
for  only  three  days  or  so. 

(2)  Quite  a  decided  erythema  with  moderate  itching  and  followed  by 
desquamation  of  dry  epithelial  flakes,  which  may  amount   to  a  regular 
peeling  of  the  affected  region;  no  raw  surface  is  produced  and  there  is  no 
pain;  it   develops  about  a  week  after  exposure,  and  it  is  three1  or  four 
weeks  before  the  skin  appears  normal  again;  slight  atrophy  of  the  skin 
may  remain  permanently,  especially  if  a  dermatitis  of  this  degree  has 
been  repeatedly  produced. 

(-'!)  After  a  period  of  incubation  of  only  two  days  a  severe  dermatitis 
with  blistering  occurs,  and  this  is  followed  by  some  destruction  of  the 
deeper  layers  of  the  skin  and  ulceration  which  takes  many  months  To 
heal.  It  is  excessively  painful  until  the  sloughs  have  separated  and  it 
leaves  a  permanent  seal'. 

(  1-)  The  most  severe  degree  has  a  period  of  incubation  lasting  for  one 
oi1  TWO  days;  begins  in  much  the  same  manner  as  the  third  degree,  but  it 
is  soon  evident  that  all  tin1  tissues  have  been  destroyed,  perhaps  to  a 
depth  of  \  inch.  The  separation  of  the  slough  is  very  slow  and  painful, 
and  the  ulceration  has  very  little  tendency  to  cicatrize.  If  at  all  ex- 
tensive it  ma}'  Take  years  to  heal  or  it  ma}'  remain  as  a  chronic  ulcer. 

The  Chronic  Dermatitis  of  the  Hands  of  ,r-Ray  Operators. — 
This  is  a  condition  produced  bv  frequently  repeated  exposures  which 
individually  would  produce  no  effect.  The  lesion  is  somewhat  of  the 
charar,  ;•)•  of  a  chronic  eczema,  and  leaves  the  hands  seamed,  scarred. 
:""'  discolored,  with  deformed  and  brittle  nails,  altogether  such  a  con- 
dition as  would  preclude1  the  use  of  the  hand  in  aseptic  surgery.  A  hand 
that  has  one*1  developed  this  condition  is  for  a  long  time  thereafter 


1144  MF.niCAL    KLKCTK1CITY    AND    R(")NT(iKN    HAYS 

more-  suse'e'ptible  to  the  x-ray.  Se>me  operators  believe  that  there  is  an 
aequireel  susceptibility  to  the  action  e>f  the  x-ray  by  which  a  strength 
of  expe>smv,  which  would  not  have1  affected  the1  operator  at  the  start, 
may  after  months'  or  years'  work  with  the1  x-ray  suddenly  produce  a 
dermatitis.  In  Dr.  Pitman's  own  recoreled  experience  he  suddenly 
developed  a  elcTinatitis  affecting  a  large  part  of  the  body.  The  history 
of  the1  use1  e>f  the'  x-ray  by  very  many  operators,  however,  does  not  lend 
support  to  the'  theory  of  a  gradually  developed  susceptibility,  but  one 
e-annot  toe)  stremgly  caution  those  using  the1  x-ray  against  a  gradually 
developed  false1  se'iise  of  security. 

A'-ray  Warts.-  After  some  years  of  x-ray  work  the1  skin  of  the 
operator's  hands  may  present  horny  growths  which  are1  hard  ami  black. 
Some  of  these  project  decidedly  above  the  level  of  the'  skin  and  some 
are  fiat  t  Plate  14).  They  seem  to  be  of  similar  structure  to  verruca 
senilis.  and  there  is  gn>at  danger  of  their  developing  into  epithelioma. 
Drs.  Kassabian.  Caldwell  and  Leonard,  and  Messrs,  (ireene,  Bauer,  and 
Baker  are1  a  few  of  our  American  x-ray  workers  who  have  lost  their  lives 
in  this  way.  Their  occurrence  indicates  that  the1  ojxTator  has  not  taken 
sufficient  precautions  against  exposing  his  hands.  They  may  be  removeel 
by  refraining  from  x-ray  exposure  and  by  applying  10  or  20  per  cent. 
salicylic  acid  aelhesive  plaster.  They  are  exceedingly  prone  to  recur. 

Another  application  is  undiluted  formalin  (40  per  cent,  formaldehyd). 
A  wooden  match  is  dipped  in  it  and  the  adherent  drop  is  applied,  to  the 
wart  alone,  every  three  e>r  six  hours  for  two  or  three-  days.  Smaller  ones 
are  killed  in  a  fe-w  days,  larger  ones  in  a  week.  After  exfoliation  the 
skin  should  be  unblemishe-el;  if  not,  repeat.  If  ulceration  occurs, 
apply  '/me  oxid  ointme-nt  or  something  similar.1  The  present  author 
has  applied  this  treatment  to  all  of  his  own  keratoses  with  permanent 
succe-ss  in  only  one.  The  first  applications  produce  no  sensation;  the' 
later  ones  are-  decidedly  painful. 

Pyrogallic  acid.  1">  per  cent,  solution  in  flexible1  collodion,  has  been 
u-ed  by  Dr.  L.  F.  Femen.  of  Denver  (personal  communication).  After 
cutting  off  the  wart  almost  to  the  bleeding-point  an  impervious  coating 
is  applied  to  the  wart  and  extends  slightly  over  the  sound  skin.  The- 
^olution  is  applied  night  and  morning  for  three1  days,  and  ofte-n  enough  te> 
maintain  the  coating  for  a  week  altogethe-r.  At  the  e-nel  of  a  wee-k  it  is 
apt  to  become  very  much  inflamed  and  painful,  and  requires  a  dressing 
of  boric  acid  ointment,  after  relieving  the  tension  by  softening  the  col- 
lodion and  removing  it.  A  black  jx-llicle  of  charred  tissue  forms  which 
separates  spontaneously  a  couple-  of  weeks  later,  leaving  a  surface 
that  look-  like  -oiind  skin,  but  which  may  require  one  more  course  of 
treatment.  For  the  author's  own  hands  this  proved  unsuccessful. 
iJcciirrence  took  place.  The  treatment  is  very  painful. 

The   d;tily   application    of    lanolin   or  of   cold   cream    or   the    like   to 

keratoses   j-  «,f  the   ure-atest    benefit,   and.    persisted   in.    has    kept 

them  apparently  innocuous  and  scarcely  perceptible  in  cases  where  they 

and  fissures  (of  the  palm1  remaining  after  x-ray 
us   cured   by   three  chlorin   ioiii/at  ions.      No  pig- 
fter  x-ray  t  real  ment  .- 
done  in  time,  i-  usually  permanently  effective-, 


.July,  I'll 2. 


i;    •.••_••:.-:  :,.    ki-ratiiM-.-;  ul    the   author'*  left    hand.      Tht-sc   had    prrsi.-tcd   for   t\vrlvi> 

IIP     m    nn\\     I-Vbruary,    I'.il.".   l)cinu  i-un-tl  nm<  tifii-r  jinothcr  li\~  radium.      I.;ili-r 

I'1-'!!     'hi    iippfaraiifi1   i~   imi    very   ditYi-n'iii .    Inn    p;iiiit'ul    fi-~nri---   >  "•i-;i-iuii;ill\- 

:    •          •    i  In    dor-uni  nf  ihi-  iudi-x-fiimi-r.      Tlii-  inti-rfi-rrs  Mjnii-what  witli   tin-  UM-  uf  tlic 

r   n    ii          '   ' ;  •       t'l'i     tfd      n-a-  an-  ciitirt-lv  i 


TIIK    X-RAY  1145 

llol/.knecht  lias  cured  about  50  cases  by  the  application  of  hard, 
filtered  .r-rays  and  an  equal  number  by  the  gamma  rays  from  radium 
(page  12(>9)." 

The  author  has  cured  several  cases  by  unfiltered  radium  rays,  apply- 
ing the  glass  tube  directly. 

Electrolytic  actions  take1  part  in  the  production  of  Rontgen  erythema, 
as  pointed  out  by  Bordier  and  Salvador,1  but  the  present  author  be- 
lieves that  the  x-ray  is  the  exciting  cause  of  the  electrolytic  action,  and 
that  there  is  no  means  of  entirely  preventing  it  except  by  interposing 
something  entirely  opaque  to  the  .x-ray. 

The  experiments  of  Strater,  Kienbock,  Oudin,  and  Scholtz  seem  to 
leave  no  room  for  doubt  that  radiodermatitis  is  due  to  the  x-rays  and 
not  to  electric  discharges  and  other  physical  phenomena  which  take 
place  around  the  tube. 

PRECAUTIONS   AGAINST   RONTGEN   RAY   INJURIES 

General  Precautions. — Measure  the  intensity  of  the  x-radiance  your 
apparatus  produces  and  learn  the  safety  limit  of  its  application.  Prac- 
tice upon  inanimate  objects  until  you  have  learned  to  produce  a  quality 
of  x-radiance  which  wrill  have  the  desired  effect  with  a  safe  exposure. 
Remember  the  cumulative  property  by  which  several  short  exposures 
have  as  great  an  effect  as  a  single  prolonged  one.  Remember  that  the 
danger  varies  inversely  as  the  square  of  the  distance  from  the  anticathode 
to  the  skin. 

1.  Precautions    in    .r-Ray    Examinations. — A.     Protection    of    the 
Patient. — 1.  Theuseof  thoj^woroscopeis  fraught  with  the  greatest  danger, 
and  I  believe  should  be  abandoned.     If,  contrary  to  my  advice,  it  is 
employed  on  rare  occasions,  the  strength  of  the  radiance  applied,  and 
consequently  the  safety  limit  of  exposure  should  be  determined  before- 
hand, and  strict  account   should  be  kept  of  the  actual  exposure.     A 
number  of  short  exposures  have  an  effect  equal  to  one  long  exposure. 
Only  the  requisite  part  of  the  patient  should  be  exposed.     The  x-ray 
should  be  filtered  by  passing  through  a  thick  screen  of  sole  leather  or 
aluminum.     The  anticathode  should  be   18  inches,  and  in  most   cases 
much  further  from  the  nearest  surface  of  the  body.     The  portions  which 
are  to  be  especially  protected  are  the  eyes,  the  testes,  and  the  blood- 
forming  organs  such  as  the  spleen.     The  greatest  danger  arises  when  a 
long  examination  is  made  or  a  long  operation  is  performed,  as  for  the 
removal  of  a  foreign  body  under  the  fi Horoscope. 

2.  In  radiography  the  strength  of  the  radiance  employed  and  the 
safety  limit  of  exposure  should  be  determined  beforehand  and  the  fact 
of  the  cumulative  effect  of  several  exposures  borne  in  mind.     Cinemat- 
ographs of  a   thick  portion  of  the  body  requiring  prolonged  exposure, 
even  with  an  intensifying  screen,  are  contrary  to  my  advice  as  involving 
a   total  exposure  which  may  be  dangerous.      The  effect  of  an  x-ray  ex- 
posure (Iocs  not  disappear  for  at  least  three  weeks.     A  heavy  sole-leather 
or  aluminum  screen  should  be  employed  and  only  the  requisite  part  of 
the   patient    exposed.       The  anticathode   should   never  be   less   than   i;> 
inches  from  the  nearest  surface  of  the  body,  and  should  be  considerably 
further  away  when  a  thick  portion  of  the  body  is  to  be  depicted.     An 
intensifying  screen,  reducing  the  exposure  to  about  one-tenth,  should  be 
u-ed  whenever  a  radiograph  is  to  be  made  through  a  thick  portion  of  a 
very  large  person,   or  when   a   number  of  radiographs  are  to  he  made 

'('.  I!.  Acad.  Sri.,  cxxviii.  Kil'J,  June  2(i,  1  *<)<). 


11-k)  MKDICAL    KLKfTHK  ITY    AM)    HUNTCKN    HAYS 

through  a  thick  portion  of  even  ;i  small  person.  The  greatest  danger 
arises  when  a  more  difficult  case  is  attempted  than  ever  before,  and  the 
most  important  tiling  is  to  place  the  tube  at  an  increased  distance  from 
the  skin.  Leukemia  and  renal  insufficiency  necessitate  caution  as  to 
any  strong  general  exposure  of  the  abdominal  organs.  The  proper 
([iiality  ot  .r-ray  is  important;  too  low  a  decree  of  penetration  lias  an 
excessive  effect  upon  the  skin  with  too  little  effect  upon  the  plate,  as  so 
much  is  absorbed  by  the  tissues.  The  unfluctuating  current  genera- 
tor, producing  .r-rays  of  approximately  uniform  wave-length,  is  an  ele- 
ment of  safety  in  radiography  by  reducing  to  a  minimum  the  admixture 
of  <oft  rays  with  those  of  the  proper  penetration. 

The  best  way  to  limit  the  application  to  the  desired  part  of  the 
patient  in  radiography  is  by  means  of  an  impervious  case  completely 
surrounding  the  .r-ray  tube,  and  having  openings  of  adjustable;  size  either 
plane  or  cylindrie  through  which  the  .r-ray  is  directed.  The  most 
satisfactory  form  of  protective  filter  is  a  sheet  of  heavy  sole-leather  in- 
side the  impervious  case  and  covering  its  orifice. 

It  is  es.-ential  to  be  able  to  maintain  the  proper  quality  of  radiance 
and  to  recognize  changes  in  the  .r-ray  tube,  which  destroy  its  effective- 
ness in  producing  a  picture  and  by  multiplying  the  length  of  time  re- 
quired add  greatly  to  the  danger  of  injury. 

]>.  Protection  <>j  tin-  Operator  in  x-Ray  Examinations. — 1.  Never  make 
direct  use  of  the  fluoroscope, 

'2.  Never  use  any  portion  of  your  body  as  a  test-object  for  measuring 
the  quality  or  the  intensity  of  the  a'-ray. 

'.).  Do  not  use  a  fluoroscopic  penet  rometer,  but  always  make  a  radio- 
graph of  the  pcnet  rometer  in  testing  a  new  tube  or  new  conditions. 

1.    Do  not  hold  the  film  or  plate  in  position  yourself. 

.">.  Never  remain  in  the  room  with  an  unshielded  .r-ray  tube  in  opera- 
tion. 

1 .  Mm  in  iscopy,  (luring  which  the  operator  stands  beyond  the  patient 
in  a  direct   line  with  the  .r-ray,  if  many  times  repeated,  means  certain 
injury  and  frequently  death.      The  danger  to  the  operator  may  be  ob- 
viated  by   his  -landing  behind  an  impervious  screen  and  viewing  the 
fluoroscopic  linage  in  a  mirror. 

2.  The  phy-iciaiis  who  have  died  from  .r-ray  injuries  have  been  vic- 
tim- chiefly  of  the  habit  of  looking  at   the  bone-  of  the  hand  as  a  means 
of  testing  1  he  quality  and  intensity  of  the  .r-ray.      The  manufacturers 

./•-ray  a  p  pa  rat  us  are  often  asked  by  prospective  customers  to  allow 
the  ./'-rav  to  shine  through  the  chest  or  some  other  part  of  the  bodv,  so 
thai  the  customer  may  see  the  fluoroscopic  image.  This  has  resulted 

ny  lingering  and  painful  deaths  among  the  men  who  have  brought 
tiif  apparatus  to  it-  present  efficiency.  No  physician  ought  ever  to 

ich    a    reque-t  . 

.1.    Many  of  the  injuries  to  physicians  have  come  from  holding  the 
'•ope    m    po-iiion    for    testing    the    radiance    with    a    fluorometer. 
ice  -hould  lie  abandoned  and  a  radiograph  made  of  such  a  test 
I  >eni  i'i-t    radiometer. 

,)•  regrets  very  much  hi-  former  practice  of  holding  the 
Him  mouth  in  dental  radiography.      The  individual  ex- 

po-  in  svi  re  «ii  .  nefil  to  the  patients,  but  their  cumulative  effect  has 
permanent  ly  d  i  _  ,:<•<]  t  lie  ope  rat  or'-  hands,  and  if  t  he  pract  ice  had  been 
contm  iei|  a  c;i  •  u'ould  have  been  produced. 

"».    llavinu     '    -       A'itche-    in    a    different    room    from    the   .r-rav    tube 


TIIK    X-KAY  1  147 

affords  perfect  protection.  And  the  same  object  may  lie  attained  by 
having  t  lie  .r-ray  t  ube  enveloped  in  a  case  opaque  to  1  he  .r-ray  and  having 
the  operator  stand  behind  a  lead  screen  and  wear  leaded  spectacles,  cap, 
apron,  and  gloves.  Repeated  exposure,  even  at  a  considerable  distance, 
to  the  unshielded  rays  from  an  .r-ray  tube  have  in  the  case  of  a  great 
many  operators  produced  sterility  and  leukopenia,  and  has  doubtless 
contributed  to  the  fatal  cases  of  .r-ray  cancel'. 

II.  Precautions  in  Rontgen-ray  Treatment.-  (A  )  J'ro/cct/o/i  of  tlic 
I'dti'int.-  1.  Do  not  give  any  Rontgen-ray  treatment  until  you  are  able 
to  measure  and  control  the  quality  and  intensity  of  the  a'-ray  and  know 
what  exposure  will  produce  a  certain  effect.  A  single  measured  dose 
sufficient  to  produce  a  more  or  less  severe  erythema  is  often  desirable, 
but  is  very  dangerous  in  the  hands  of  the  inexperienced. 

2.  Expose  only  the  desired  portion,  shielding  other  parts  by  dia- 
phragm or  cylinders  or  by  sheet  lead  or  the  like,  fastened  around  the 
part  to  be  treated. 

:•>.  l"se  a  quality  of  ray  adapted  to  the  case — as  nearly  as  possible 
all  soft  rays  for  a  cutaneous  lesion  and  all  rays  of  greater  penetration  for 
deep  lesions.  The  soft  rays  are  obtained  from  a  tube  with  a  low  degree 
of  vacuum,  and  expecially  with  a  converter  producing  a  constant  poten- 
tial. The  rays  of  greater  penetration  may  be  produced  by  a  tube  with  a 
higher  degree  of  vacuum,  especially  if  excited  by  a  converter  producing  a 
constant  potential.  Screens,  of  aluminum  or  of  sole-leather  are  often 
useful  in  arresting  whatever  soft  rays  may  be  present. 

4.  I'se  the  cross-fire  system  in  treating  a  deep  lesion,  so  that  no  one 
portion  of  the  surface  will  bear  the  entire  brunt. 

.">.  The  deeper  the  lesion  the  further  the  anticathode  should  be  from 
the  skin.  If  the  anticathode  is  only  4  inches  from  the  skin,  the  latter 
will  be  twice  as  near  the  anticathode  as  a  lesion  4  inches  below  the  sur- 
face, and  the  skin  would,  even  if  distance  were  the  only  factor,  receive  a 
radiance  four  times  as  strong  as  the  deep  lesion.  The  percentage  ab- 
sorbed by  tin1  tissues  overlying  the  deep  lesion  increases  the  difference 
in  the  effect,  but  is  about  the  same  whether  the  tube  is  near  the  surface  or 
far  from  it. 

I).  1  )o  not  be  deceived  by  the  theory  that  any  .r-radiance  is  so  entirely 
made  up  of  hard  rays  that  it  can  be  safely  applied  with  the  tube  very  near 
the  surface  and  in  extremely  large1  doses.  Surface1  injuries  and  injuries 
to  the  i issues  of  the  intestines  have  followed  therapeutic  applications 
1  >;ised  upon  this  theory. 

7.  The  eyes,  testes,  ovaries,  and  hair  are  portions  to  be  especially 
protected  from  accidental  exposure. 

( J) »  Protect/on  of  the  Operator  in  Rirntgcn-roij  Tnatnimi. — The  same 
precautions  are  absolutely  necessary  as  in  .r-ray  examinations. 

The  Prevention  of  .r-Ray  Dermatitis. — (1)  The  patient  should  not 
be  exposed  too  long,  too  frequently,  or  to  too  strong  a  radiation.  The 
strength  of  the  radiation  depends  partly  upon  the  energy  given  out  by 
the  ./'-ray  tub--  and  partly  upon  the  distance  at  \\hich  it  is  placed,  the 
effect  diminishing  as  t  he  square  of  the  distance  increases.  For  instance, 
at  twice  the  distance  from  the  anticathode  the  region  exposed  is  sub- 
mitted to  only  one-quarter  t  he  st  ren.ui  h  of  ./'-ray.  The  length  of  time  is, 
of  course,  dependent  upon  the  strength  of  the  application.  For  those 
who  have  not  the  different  apparatus  for  measuring  the  strength  of 
the  application  a  good  limit  is  nine  minutes' exposure,  at  a  distance  of 
one  foot  from  t  he  anticathode,  and  a  st  rengt  h  of  .r-ray  which  will  pen  nil 


IMS  MKIHl  AL    KLKCTHICITV    AND    RONTOKX    HAYS 

the  bones  of  the  hand  to  be  seen  faintly  at  a  distance  of  2  feet  from  the 
anticathode.  A  stronger  radiance1  would  call  for  a  correspondingly 
shorter  exposure.  Sometimes  in  treating  the  side  of  the  neck  it  will  be 
found  that  the  shoulder  is  much  nearer  the  tube  than  the  part  to  be 
t  reated.  and  if  so  it  would  receive  a  dangerous  amount  of  radiation  unless 
shielded  from  the  rays.  In  .r-ray  treatment  it  is  always  desired  to  pro- 
duce some  effect  upon  a  certain  area  of  tissue,  and  all  other  parts  of 
the  patient  should  be  protected  either  by  lead  or  other  .r-ray  proof 
sheets,  or  by  encasing  the  tube  in  some  kind  of  loeali/ing  shield.  There 
is  some  protection  of  the  part  exposed  by  interposing  a  thin  metallic 
screen,  like  ihe  author's  screen  for  soft  rays,  or  even  by  the  clothes. 
Begin  with  smaller  doses  than  indicated  above  and  do  not  repeat  them 
oftener  than  once  in  three  days.  Holzknecht's  chromoradiometer 
furnishes  a  direct  measure  of  the  amount  of  radiation  to  which  the 
region  is  exposed.  Three  Holzkneeht  units  applied  at  one  session  will 
produce  a  visible  reaction  upon  the  face,  and  this  limit  should  not  be 
reached  in  radiography.  Hut  in  radiotherapy  it  will  be  noted  that 
certain  cases  require  applications  of  3  or  4  Holzkneeht  units,  which, 
however,  should  not  be  repeated  until  the  reaction  has  subsided. 
This  may  require  an  interval  of  three  weeks  or  more.  If  the  applica- 
tion is  to  be  repeated  once  a  week  half  the  above  dose  is  the  limit, 
and  if  used  more  frequently  a  still  smaller  fraction  of  the  dose  is  applied. 
A  low  vacuum-tube,  giving  a  brilliant  radiance,  produces  a  much  greater 
effect  upon  the  superficial  tissues  than  a  tube  with  a  high  vacuum  and 
greater  penetration.  The  amount  of  radiance  bears  a  certain  relation 
to  the  strength  of  the  current  actually  passing  through  the  tube,  as 
indicated  by  a  milliamperemeter  introduced  between  the  coil  and  the 
tube,  and  it  has  been  hoped  that  this  one  measurement  would  fully 
indicate  the  strength  of  the  radiance1,  and  that  we  could  simply  apply  a 
Mrength  of  so  many  milliamperes  for  such  a  time  at  such  a  distance. 
This,  however,  is  not  sufficient.  A  Miiller  heavy  target-tube,  excited 
bv  a  12-inch  coil,  \vitha  Caldwell  interrupter  giving  about  5000  inter- 
ruptions a  minute,  with  a  primary  current  of  '.*  amperes,  and  about  3 
inches  resistance  in  the  tube,  allows  1  ma.  to  pass.  This  is  with  con- 
siderable resistance  in  the  rheostat;  but  with  all  the  resistance  cut  out 
by  turning  the  rheostat  all  the  way,  the  current  trough  the  tube 
iii(  reases  to  2',  ma.  and  the  radiance  becomes  much  more  brilliant.  "We 
ni  i\v  connect  t  he  same  tube  in  precisely  the  same  condition  as  to  vacuum 
wuh  the  prime  conductors  of  a  static  machine,  with  six  revolving  glass 
plates  2t>  inches  in  diameter,  and  making  about  300  revolutions  a 
minute,  the  machine  being  in  first-class  working  order.  "We  find  that  1 
:  .  i-  passing  through  the  tube,  but  that  the  radiance  is  not  nearly 
as  powerful  as  when  1  ma.  was  passed  through  the  tube  by  the  coil, 
ihe  compari.-on  is  not  quite  a  fair  one  that  is.  comparing  the 
•t  of  1  ma.  through  the  .r-ray  tube  in  conjunction  with  the  coil  and 
'!,>•  sair:<;  in  coniunciion  with  a  .Malic  machine.  "\\  hile  it  is  not 
v  known,  yet  it  is  a  fact  which  can  be  easilv  demonstrated,  that 
,a\  in-  a  parallel  spark-irap  of  1  inches  on  an  ./'-ray  coil  will  only 
:  lid  -park-nap  of  ',  inch  on  a  Matic  machine. 

!o  the  use  of  the  mill ia mpereniet ( T,  Lewis  Jones  went 
lis  matter  very  carefullv.  and  his  conclusions  were  that  as  long 
parallel  -pafk-^ap  of  the  tube  did  not  exceed  ~>  inches,  the  mim- 
milliampere-.  through  the  tube  irave  a  fair  idea  of  its  .r-rav  value 


;  on  the  same  a|)paratus,  using  the  same  rate  of  in- 
<ame  strength  of  primary  current. 

The  milliamperemeter  does  not  really  give  such  information,  so  that 
another  operator  using  a  different  make  ol  apparatus  would  be  able 
to  absolutely  reproduce  the  same  effect,  but  it  does  give  the  individual 
opera  t  or  a  good  guide  as  to  t  he  work  of  his  t  ube,  and  it  he  keeps  t  he  rate 
of  interruption  constant,  the  primary  current  constant,  and  the  resist- 
ance of  his  rheostat  constant,  then  the  meter  will  be  of  decided  benefit, 
so  l  hat  t  wo  facts  are  evident ,  t  he  milliamperage  passing  t  h rough  t  he  1  ube 
1-  not  by  itself  a  sufficient  measure  of  the  amount  of  .r-ray  the  patient 
is  receiving,  and  an  amperemeter  on  the  primary  circuit  by  itself 
is  still  less  so.  The  only  safe  guides  are  wide  experience  or  Ilolx- 
knecht's  chromoradiometer  or  some  similar  quantitimeter,  combined 
with  some  good  qualit imeter,  like  Walter's  or  Benoist's.  The  in- 
tensity of  the  radiance  may  be  measured  by  the  author's  method,  but. 
of  course,  we  make  use  of  the  radiometer  and  spintremeter  for  determin- 
ing the  degree  of  vacuum.  By  the  use  of  I lol/.knecht 's  chromoradiom- 
eter for  determining  the  amount  of  .r-ray,  combined  with  a  radiom- 
eter and  a  spintremeter  to  show  the  degree  of  vacuum  of  the  tube, 
and  hence  t  he  quality  of  t  he  ray,  and  I  he  aut  hor's  met  hod  of  measuring 
tlie  intensity  of  the  ray,  we  are  able  to  administer  the  same  doses  as  are 
recorded  in  the  reports  of  worker.-  in  all  parts  of  the  world,  and  with 
apparatus  varying  wonderfully  in  efficiency.  It  is  nut  necessarv  to 
note  the  change  of  color  in  the  prepared  pastil  of  the  Bolzkneeht 
chromoradiometer  for  every  exposure,  but  it  is  very  desirable  to  ex- 
periment with  it  until  you  have  determined  for  your  own  apparatus 
how  many  minutes'  exposure  at  a  certain  distance  and  under  certain  con- 
ditions will  produce  1,  2,  or  o  llolxknecht  units. 

Merely  as  an  example,  it  may  be  stated  that  a  certain  12-inch  coil 
with  a  Wehnelt  interrupter,  a  primary  current  of  10  amperes,  a  tube  of 
vacuum  No.  (i  (  Benoist  ).  was  found  to  produce  4  llol/knecht  units  upon  a 
surface  •">  inches  from  the  ant  icathode  during  an  exposure  of  ten  minutes. 

(2)  A  screen  for  soft  rays  may  be  used.  A  thin  sheet  of  aluminum, 
or  of  tin-foil,  or  a  thick  sheet  of  leather  may  be  interposed  between  the 
.r-ray  tube  and  the  portion  to  be  treated.  The  rays  which  produce 
dermatitis  are  those  which  are  of  little  penetration  and  which  are  con- 
sequentlv  absorbed  bv  the  skin.  A  screen  for  soft  rays  will  arrest  these 
rays  and  allow  onlv  the  more  penetrating  rays  to  reach  the  patient,  and 
these  have  very  much  less  effect  in  the  direct  ion  of  producing  dermatitis. 
I'hi-  protection  is  not  absolute,  however,  and  an  overexposure  is  to  be 
avoii  led. 

(o)  ( leyser  has  suggest  ed  that  i  he  cause  of  dermatitis  is  not  the  .r-ray, 
Inn  an  elect  rost  at  ic  condition  which  may  be  avoided  by  placing  the  t  ube 
directly  in  contact  with  the  part  to  be  treated.  The  author  does  not 
regard  this  as  probablv  correct,  and  recommends  avoidance  ot  over- 
dosage  when  the  Kontgen  ray  is  applied  in  this  way. 

Modern  apparatus,  such  as  the  ( 'oolidge  tube  and  the  transformer 
and  the  oscilloscope,  make  it  entirely  possible  to  produce  .r-rays  cor- 
re-poiidiim'  exactly  to  a  specified  spark  length,  free  from  inverse  dis- 
With  these  factors  secured,  the  do-aue  may  be  accurately 
-  so  many  milliampere  second-  with  such  a  spark  equivalent 
a  -econdary  voltage  if  you  are  sure  of  your  voltmeter)  at  such 
ce  through  -ndi  a  filter  or  without  any  filter, 
i-  now  i  I!i20;  the  method  of  choice. 


RONTGENOTHERAPY 

THE  TREATMENT  OF  DISEASE  BY   THE  .Z-RAY 

IT  has  been  found  by  actual  observation  that  the  .r-ray  has  a  cura- 
tive influence  upon  quite1  a  variety  of  morbid  e-onditiems.  It  is  not  a 
sufficiently  powerful  bactericide  to  have  any  direct  effect  upon  bacteria 
in  doses  which  would  be  harmless  to  the  tissues,  and  ye>t  it  is  an  ex- 
cellent remedy  in  myeotic  skin  diseases.  This  is  due  to  its  depilatory 
action  and  to  the  slight  stimulation  it  produce's.  It  has  a  very  mark- 
edly beneficial  effee't  em  tubercular  proevsses.  probably  by  an  alterative 
and  stimulating  e'ftect.  And  of  a  like  nature  is  it<  effect  upon  rheumatic 
01-  gouty  eleposits  about  joints  or  nerves,  and  upon  a  variety  of  condi- 
tions, from  colitis  to  keloid.  It  has  a  specific  action  in  e'pithelioma  and 
to  some  extent  in  every  either  form  of  malignant  disease.  It  is  a  power- 
ful analgesic. 

The  method  e>f  application  is  by  allowing  the1  .r-ray  te>  shine1  eliive-tly 
upon  the1  affected  part  from  a  tube1  with  a  vae-uum.  whie-h  eh'penels  tipon 
the  depth  of  the  lesion,  and  with  a  strength  and  at  a  distance1  and  for  a 
length  of  time1  sufficient  to  proeluce1  a  certain  effe'ct  upon  the1  tissue's. 
Different  plans  may  be  adopted;  the'  exposures  may  be1  mild  and  iv- 
peated  e've-ry  day  or  e'veTy  twe>  e>r  thive  days,  and  a  conditiem  of  ivae-tiem 
gradually  reached  and  maintaine-el:  single1  large1  dose's  may  be  use'el 
sufficient  to  produce1  the1  degree  e>f  reaction  required  in  that  particular 
eli-ea-e.  and  if  necessary  repeated  after  the'  three  or  four  or  more1  we'e'ks 
which  it  takes  for  the'  traction  to  de've'lop  and  subsiele1:  eir  half  eloses 
may  be  used,  each  of  which  will  e'xcite  a  slight  traction,  anel  the  dose's 
may  be  repeated  every  week  or  two.  The  method  by  frequently 
repeated  small  doses  is  the  one  which  was  at  first  tise-d  in  this  country, 
[l  would  be  dangerous  guesswork  te>  apply  the  .?'-ray  for  treatment 
without  at  least  measuring  the  spark  equivalent,  suppressing  all  inverse 
discharge  and  measuring  the  milliampe'rage. 

For  doses  repeated  every  three  days  the  wall  of  the  tube  should  be>  at 
a  di-tance  of  '.)  inches  from  the  nearest  exposed  -urface1.  If  only  a  small 
area  i-  to  be  treated  the  tube  may  be  brought  nearer  and  the  time1 
peculated  according  to  the  -quare  of  the  distance.  Thus,  at  a  distance 
of  '•>  indie-  from  the  wall  of  the  tube  or  (i  inche-  from  the  anticathode  or 
di-k  fVom  which  the  rays  radiate,  an  exposure  of  1  wo  minute's  and  a  quar- 
uld  produce  the  >ame  effect  as  nine  minute-  at  a  distance  of  '.• 
t  he  wall  of  t  he  1  ube  or  \'2  inches  from  t  he  a  lit  icat  hode1.  In 
leiuhboritlg  part-  -hould  be  protected  by  -heel  lead  or  the 
iii  a  locali/iii"  >hield  enca-ing  the  tube.  Thi.-  is  e-qually 
i't  her  the  di.-t  aiice  be  urea  t  or  small,  .r-1  tax  met  a  I  i  (  'on  ley 
\\  .  '2~>\\\  Street.  New  York  i-  very  convenient  for  pmtec- 
compound  '')'  lead  and  tin,  and  doe-  not  rub  ofl  on  the 
ild.  The  thin  weight  i-  riuht  for  this  purpo-e: 
ill-  I  loot  \\  idi  •  a  nd  co-t  -  1 0  or  t .")  cent  s  a  pound.  Sheet  - 


RONTGENOTHERAPY  1 151 

of  this  foil,  measuring  12  x  IS  inches,  may  he  put  over  the  head 
and  face,  and  other  sheets  with  a  hole,  which  may  he  made  larger  or 
smaller  by  turning  back  Maps,  may  be  applied  over  the  region  1o  be 
treated.  Large  L-shaped  pieces  are  useful  in  many  places,  as  for 
exposing  the  shoulder  while  protecting  adjacent  parts.  Other  opera- 
tors use  a  vertical  screen  of  sheet  lead  with  an  adjustable  orifice, 
and  others  sheet  lead  covered  with  rubber.  The  x-ray-proof  rub- 
ber compound,  made  for  gloves  for  protecting  the  operator's  hands 
from  dermatitis,  makes  a  flexible  and  effective  protection,  but  is 
rather  expensive.  With  a  substantial  and  readily  adjustable  x-ray 
tube  stand,  and  a  localizing  shield  which  is  opaque  to  the  x-ray  and 
almost  completely  surrounds  the  tube,  the  treatment  of  any  part  of 
the  surface  of  the  body  is  a  very  simple  matter.  Different  diaphragms 
make  the  orifice  through  which  the  x-ray  shines  large  or  small,  and 
vulcanite  tubes  are  useful  for  introduction  into  the  mouth  or  vagina. 

Treatment  tubes  of  various  patterns  have  been  designed  by  Cossar,  of 
London,  and  Morton,  Cleaves,  and  Caldwell,  of  Xew  York,  and  by  the 
author.  In  one  type  the  bulb  is  large  enough  to  avoid  overheating  and 
rapid  change  in  vacuum,  but  is  made  of  lead  glass  opaque  to  the  .r-ray 
while  transparent  to  ordinary  light.  Opposite1  the  anticathode  there 
is  a  prolongation  through  which  the  .r-ray  passes,  the  extremity  being 
made  of  glass  which  is  transparent  to  the  x-ray.  There  is  a  glass  handle, 
bv  which  the  tube  may  be  held  in  position  for  applying  the  .r-ray  to 
some  small  area  like  an  epithelioma  near  the  eye,  or  the  prolongation  may 
be  passed  into  the  vagina  or  mouth  for  the  treatment  of  a  cancer  of  the 
uterus  or  of  the  tonsil.  In  any  case  it  is  desirable  to  slip  on  a  rubber 
cover,  which  is  used  only  for  a  single  patient. 

In  another  type  of  treatment  tube  the  bulb  and  prolongation  are 
similar  to  those  in  the  one  just  described,  but  there  is  no  anticathode. 
The  concave  cathode  directs  the  cathodal  stream  into  the  prolongation, 
and  when  this  stream  strikes  the  glass  Avail  of  the  prolongation  the  x-ray 
is  produced.  Such  a  tube  may  be  successfully  used  in  the  rectum,  but, 
of  course,  the  prolongation  must  be  kept  cool  by  a  constant  flow  of  water 
through  an  outer  jacket. 

Still  another  type  has  the  anticathode  near  the  end  of  the  pro- 
longation, directing  the  x-ray  laterally,  and,  because  of  its  close  prox- 
imity to  the  glass,  blackening  the  active  part  of  the  tube  very  quickly, 
Such  a  tube  mav  have  a  heavily  insulated  wire  returning  from  the  posi- 
tive pole  or  there  may  be  no  wire  there.  In  the  latter  case  the  coil 
must  not  be  a  too  powerful  one  and  the  positive  pole  of  the  coil  is  some- 
times grounded.  This  tvpe  of  tube  is  less  desirable  than  the  others. 

A  fourth  type  is  the  unipolar  x-ray  tube,  constructed  on  much  the 
same  lines  as  the  last  described,  without  a  positive  wire.  The  cathode 
is  connected  with  an  Oudin  resonator.  The  high-frequency  and  high- 
tension  current  produces  a  cathodal  stream  which  impinges  upon  the 
anticathode  and  is  then  converted  into  the  x-ray.  These  are  made  in 
small  sixes  for  use  in  the  mouth  and  get  overheated  if  run  for  more  than 
about  half  a  minute  at  a  tune.  As  the  anticathode  is  so  near  the  surface 
to  be  treated,  one  or  two  short  applications  are  enough.  This  tube,  of 
course,  acts  also  as  a  u'la<s  vacuum  electrode  for  the  application  of 
hiti'h-frequency  current-.  It-  practical  value  is  problematic. 

For  general  radiotherapy  the  Standard  Coolidge  tube  with,  a  solid 
tunirsten  anticathode  has  proved  verv  doirable.  The  essential  feature 


11.VJ  MF.DH'AL    KLKelRiriTY    AND    H(")NT(  iKN    KAYS 

of  a  tube  for  therapeutics  is  the  ability  to  stand  prolonged  use  with 
fairly  heavy  currents  without  overheating,  and  the  possession  of  a 
regulating  device  by  which  the  resistance  may  be  readily  and  accurately 
adjusted.  The  best  generator  is  a  step-up  transformer  with  a  high- 
tension  rectifier  or.  still  better,  the  author's  generator  of  constant  high- 
tension  current.  With  either  of  these  and  the  ('oolidge  tube  .r-ray 
do.-aire  becomes  a  mathematical  certainty,  in  using  a  coil,  a  pri- 
mary current  of  more  than  9  amperes  will  seldom  be  required  for 
treatment,  and  with  some  interrupters  a  primary  current  of  l>  or  even 
o  ampere-  i-  ample.  The  author  greatly  prefers  a  mechanical  inter- 
rupter, such  as  the  Wappler  wheel  interrupter,  for  radiotherapy. 
Six  amperes  would  be  the  current  furnished  by  a  Wehnelt  interrupter 
in  which  only  the  tip  of  the  platinum  is  exposed,  and  this  is  1  milli- 
meter in  diameter,  no  resistance  being  interposed  by  the  rheostat. 
A  ('aldwell  or  Simon's  interrupter  may  have  small  or  comparatively 
large  holes  between  the  two  portions  of  liquid,  or.  in  some  cases,  the 
-ixe  of  the  opening  is  adjustable.  If  the  openings  are  small  the  in- 
terruptions are  rapid  and  the  strength  of  the  primary  current  is  per- 
haps only  from  3  to  .">  amperes  without  any  rheostat,  but  the  second- 
ary current,  as  indicated  by  ( laift'e's  milliamperemeter  and  by  the  .r-ray, 
produced  will  be  very  good  indeed.  With  larger  holes  the  interruptions 
are  -lower,  the  noise  produced  is  of  a  lower  pitch,  and  the  primary  cur- 
rent may  be  as  much  as  10  or  12  amperes  if  no  rheostat  is  used.  This 
produces  a  brilliant  .r-ray  and  a  much  stronger  secondary  current 
than  with  the  smaller  and  more  rapid  interruptions.  Hut  this  strength 
is  usually  cut  down  by  the  rheostat  until  the  secondary  current  and  the 
./•-ray  are  about  the  same  as  those  with  the  more  rapid  interruptions. 
The  primary  current  in  this  case  remains  quite  heavy,  perhaps  S  or  9 
ampere-.  With  a  coil  the  greatest  amount  of  self-induction  in  the 
primary  winding  i-  desirable  for  treatments.  For  several  treatments 
in  rapid  succes-ion  it  will  be  found  necessary  to  have  at  least  two  tubes 
in  readiness.  The  anticat  hode  gets  very  hot  from  continuous  use,  gives 
out  an  injurious  amount  of  radiant  heat,  and  throws  off  metallic  particles 
which  blacken  the  tube.  The  gas-filled,  water-cooled  tube  runs  for  a 
long  time  without  a  change  in  its  degree  of  vacuum  with  the  strength  of 
current  -uital  >le  for  treatment . 

The  important  measurements  in  treatment  are  the  quality  and  the 
amount  of  ./'-rav.  The  first  must  be  determined  partly  by  means  of 
the  spint  remeter,  showing  the  length  of  spark  which  will  pass  between 
the  pole-  of  the  ./'-ray  generator  rather  than  pass  through  the  tube. 
The  hiirher  the  degree  of  vacuum  in  a  gas-tilled  tube,  the  greater  is  its 
resistance  to  the  pa--aue  of  the  current  and  the  longer  is  the  spark  it 
will  back  up.  Another  method  of  determining  the  quality  is  by  noting 
with  the  lluoro-cope  the  degree  of  penetration  of  the  ./'-ray  produced. 
excee 
-  oW 


to  make  a  pract  ice  of  1<  Miking  at 


d.  although   th< 


se  of  a  radiometer  in  which  the  decree  of 


et al  thn High  which  the  ./'-ray 
er's  and  I>enoi-l's  radiom- 
penet  rat  loll.  i  lie  mea 

appneo  may  i  >e  by  Sabouraild  and  Noire  s 
-    chromoradiomet er    ID.     I  1  .">  1   .    which 


RONTGENOTHERAPY  ]  15.'] 

responding  to  a  certain  number  on  a  color  scale.  To  give  the  same 
treatment  recommended  by  some  authority  it  is  only  necessary  to  u.-e 
the  same  resistance  and  to  continue1  the  application  until  1  he  prescribed 
nnmlier  of  Ilol/knecht  unit-  have  been  applied.  Thi.-  doe-  not  mean 
that  it  is  necessary  to  use  one  of  these  pastils  every  time  the  .r-iav 
i-  applied,  or  even  that  it  is  absolutely  necessary  for  everyone  u.-ing 
the  .r-ray  to  have  the  Ilolzknecht's  chromoradiometer,  but  it  is  very 
desirable  that  everyone  should  know  the  strength  of  his  apparatus 
in  term-  of  these  international  units.  Thus,  one  >hould  know  how 
many  minutes'  exposure  it  takes  to  equal  •*>  Holzknecht  unit-  with 
such  a  tube  and  vacuum,  and  -uch  a  primary  winding,  and  such  an 
adjustment  oi  the  rheostat  and  interrupter,  and  with  or  without  spark- 
gaps  and  at  such  a  distance  from  the  anticathode  to  the  surface  treated, 
and  with  .-uch  readings  ot  the  amperemeter  on  the  primary  circuit 
and  the  miliiamperenieter  on  the  wire  pa>-ing  from  the  coil  to  the 
.T-ray  tube  and  with  such  a  spark  equivalent.  The  efficiency  of  dif- 
ferent tubes,  coils,  interrupters,  transformers,  and  static  machines 
u-ed  to  vary  so  much  that  the  strength  of  the  application  could  not  be 
stated  accurately  in  ampere-  or  milliamperes.  The  ( 'oolidge  tube  and 
the  u'eiierators  made  to  excite  it  have  made  it  possible  to  state  the  ap- 
plication as  of  -uch  a  number  of  inches  back-up  and  such  a  number  of 
milliamperes,  and  with  these  generators  the  same  technic  may  be 
used  with  a  uas-filled  tube.  ( tne  may  begin  with  the  dose  indicated  on 
p.  1  1  17,  and  gradually  acquire  a  knowledge  of  safe  and  effective  dosage, 
or  one  may  watch  the  work  of  an  expert  long  enough  to  be  able  to  rec- 
oirni/e  the  different  qualities  and  intensities  and  to  know  their  dosage: 
or.  better  -till,  one  may  have  the  different  instruments  of  precision,  and 
thu-  be  able  to  more  accurately  duplicate  the  applications  recommended 
by  workers  in  different  part-  of  the  world.  Attention  to  detail  i- 
absolutely  e.-sential  in  .r-ray  work,  and  the  operator  should  record 
every  condition  under  which  each  exposure  to  the  .r-ray  was  made. 

THE   TECHNIC   OF   RONTGEN   THERAPY 

An  >>-  or  12-inch  coil  may  lie  u>ed.  and  its  primary  winding  should 
be  -uch  a-  to  give  a  variable  -elf-induction,  and  u-ually  the  greatest 
amount  of  -elf-induction  i-  used.  The  details  of  this  and  other  technical 
point-  are  more  fullv  u'one  into  in  the  section  on  Radiographie  Technic. 
A  YVehnelt  interrupter  with  a  platinum  rod  1  mm.  in  diameter  and  with 
ju-t  it-  tip  exposed,  or  a  mechanical  wheel  interrupter,  or  a  Caldwell- 
Simon  interrupter  with  comparatively  >mall  holes  will  be  found  to  give 
the  be-t  eurrent.  This  should  have  rapid  interruption-  and  a  strength 
of '_'  to  1  or  ")  ampere-  when  properly  regulated  by  the  u.-e  ot  t lie  rheostat. 
A  transformer  with  high-ten -ion  rectifier  or  an  unfluctuating  current  gen- 
erator may  be  used,  but  with  a  much  weaker  current  than  for  radiog- 
raphy. The-e  are  preferable  to  an  induction  coil.  The  intensity  of  the 
.r-ray  it-<'lf  -hoiild  be  measured  with  a  certain  ,-trenuth  of  eunent.  It 
\\ill  be  easy  to  duplicate  the  condition-  at  any  time.  The  Standard 
('oolidge  tube  with  a  -olid  tumi.-ten  anticathode  simplifies  the  technic 
very  much,  or,  among  gas-filled  t  ube-.  a  wat er-co< >led  t  ube  i-  excellent,  7- 
inch  t  uni!>t  en  t  aru'et  t  ube  or  wa  t  er-c<  >oled  1  ube  ;  Fig.  1S7  ]  are  very  >at  is- 
t'actory.  It  ha-  often  been  stated  that  the  vacuum  should  be  medium  or 
low.  resistance  1  or  2  inches,  and  radiometer '2  to  1  Heiioi-t  for  an  effect 
upon  the  -kin:  but  the  author  believe-  thai  for  the  be-t  result-  in  skin 


1154  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

lesions  as  well  as  for  deep  therapy  a  back-up  of  6  inches  is  required.  The 
current  passing  through  the  tube  itself  should  be  1  to  3  ma.  Spark-gaps 
between  the  coil  and  tube  are  usually  not  required,  but  should  be  used 
if  the  tube  shows  signs  of  inverse  discharge,  especially  by  an  oscilloscope 
or  by  the  absence  of  a  sharp  equatorial  line  dividing  the  light  from  the 
dark  hemisphere.  (The  two  positive  terminals  are  connected  by  a  wire, 
or  only  the  anode  or  the  anticathode  may  be  used  to  get  the  best  ra- 
diance.) The  tube  should  be  so  placed  that  its  long  axis  is  parallel  to  the 
surface  to  be  treated;  the  wires  are  in  this  way  as  far  as  possible  from  the 
patient.  The  radiance  is  equally  intense  in  practically  all  directions  in 
front  of  the  anticathode. 

The  neighboring  parts  should  be  protected  by  the  Ripperger,  Fried- 
lander,  or  a  lead  glass  shield,  or  by  sheets  of  x-ray  metal,  or  by  the  use  of 
.r-ray  tubes  made  of  lead  glass  opaque  to  the  x-ray  except  in  the  direc- 
tion of  the  part  to  be  treated. 

A  stand  should  be  used  substantial  enough  to  stand  the  weight  of  the 
tube  and  shield,  and  with  arrangements  by  which  the  tube  may  be 
readily  adjusted  in  any  position.  Such  a  one  is  Ripperger's,  slightly 
modified  by  the  present  author. 

The  Dosage  of  the  x-Ray.  This  is  a  matter  which  is  influenced  by 
various  considerations  which  produce  the  greatest  possible  difference 
in  the  intensity  of  the  radiation  from  different  apparatus  and  from 
the  same  apparatus  differently  manipulated.  Two  entirely  different 
methods  of  administration  are  in  use.  In  one,  one-sixth  erythema  doses 
are  given  at  intervals  of  three  days  until  a  reaction  of  the  desired  degree 
is  gradually  produced.  The  operator  must  not  guess  at  the  above  dose, 
but  must  know  how  to  measure  it.  A  good  example  of  this  fractional 
dose  is  (i-inch  spark,  3  milliarnperes;  10-inch  distance,  3  mm.  aluminum 
filter  for  two  minutes.  The  other  method  requires  a  knowledge  of  the 
dose  which  will  produce  the  necessary  reaction  with  a  single  application. 

The  dose  in  the  second  met  hod  is  equally  easy  to  define,  but  requires 
a  special  apparatus  for  its  measurement  or  very  great  experience  and 
judgment  in  applying  the  .r-ray.  One  special  apparatus  is  Holzknecht's 
chromoradiometer.  A  chemically  prepared  pastil  is  exposed  at  half 
the  distance  from  the  tube  to  the  part  under  treatment,  and  the  ap- 
plication is  continued  until  the  pastil  has  changed  color  to  corre- 
spond with  1,  2,  o,  4,  or  possiblv  •">  of  the  color  scale.  This  indicates 
thai  the  irradiation  ha-  amounted  to  a  corresponding  number  of  IIolx- 
knecht  units.  One  II.  is  about  a  third  of  the  amount  of  t  lie  .r-ray  that 
uiu-t  lie  applied  at  one  -e-sion  in  order  to  produce  a  visible  reaction 
on  the  face;  M  or  1  II.  i-  a  full  dose,  and  would  not  be  repeated  until  the 
reaction  had  developed  and  subsided,  usually  not  for  several  weeks; 
•")  II.  with  1-inch  resistance  is  a  verv  large  dose,  sometimes  required  in 
cancer  cases;  2  II.  is  a  half  dose,  which  may  be  repealed  every  two  weeks 
and  will  maintain  a  con-taut  moderate  reaction.  In  every  case  it  is 
nece-~ary  that  the  tube  should  be  of  the  propel'  degree  of  resistance, 
although  Ilolxknecht  thought  originally  that  a  certain  number  of  units 
fe(|  liv  hi-  instrument  would  product'  the  same  effect,  whether 
•-i-1ance  were  high  or  low.  This  has  not  proved  to  be  the  case, 
ipparatu-  doe-  mea-ure  the  amount.  The  I  lol/knecht  (II) 
it.  but  without  the  chromoradiometer  this  would  require 
which  the  distance  and  duration  of  exposure  would  be 
and  the  intensity  of  the  irradiation  would  be  the  most 


RONTGENOTHERAPY 


1155 


complex,  factor.  The  latter,  of  course,  is  determined  by  the  spark 
equivalent  and  the  milliamporagc.  For  this  measurement  of  the 
Holzknecht  unit  see  page  11(>8. 

llolzknccht  Unit*  tit  Sic  in  Distance. — McKee  so  measures  his  dosage, 
and  a  discoloration  of  1  II  would  be  equal  to  4  H  if  the  pastil  were 
at  the  usual  one-half  skin  distance. 

daiffe'x  Mcdxurcnicnt  of  .r-h'tii/  DOMUJC.* — His  method  employs  a 
piece  of  barium  platinocvanid  screen,  which  is  placed  upon  the  surface  of 
the  body  near  the  part  under  treatment.  A  part  of  the  screen  is  shielded 
from  the  .r-ray  by  different  thicknesses  of  some  such  material  as  lead- 
toil.  The  general  surface  soon  loses  1'ts  brilliancy  of  tluorescence,  while 
the  parts  which  are  shielded  do  so  more  slowly.  The  latter,  however, 
is  only  a  matter  of  time.  The  unshielded  part  undergoes  a  maximum 
loss  of  brilliancy  which  is  attained  by  the  different  shaded  portions  in 
succession.  To  see  what  amount  of  .r-ray  has  been  applied  the  barium 
platinocvanid  screen  is  removed  from  behind  the  shield  and  held  up  to 


1  i-.  s().s 


the  .r-ray.  Some1  parts  of  the  shaded  portion  mav  be  found  to  have 
exactly  the  same  loss  of  brilliancy  as  the  unshaded  portion;  the  number 
of  pails  which  have  attained  the  maximum  loss  of  brilliancy  shows  the 
amount  of  .r-ray  applied.  Such  an  apparatus  should  be  standardized 
so  thai  each  unit  would  be  equal  to  1  llolxknecht  unit  or  a  certain  frac- 
t  ion  thereof. 

Scl<  nhnti  ('<il  in  x-I\ai/  Mcaxurancnt. —  fleo.  C.  Johnston,  in  America." 
and  Luraschi'  describe  a  method  by  which  the  varying  resistance  of  a 
-eleiiimn  cell  when  exposed  to  the  .r-ray  is  u-ed  as  a  measure  of  the 
intensity  of  the  latter.  The  general  arrangement  is  shown  in  Fig.  SO'.). 
A  dry-cell  battery  generates  a  current  the  strength  of  which  is  indicated 
on  the  millianiperemeter  and  is  dependent  upon  the  resistance  in  the 
selenium  cell  and  in  a  certain  adjustable  additional  resistance;  the  latter 
is  regulated  so  as  to  have  the  indicator  point  to  the  /ero  mark  on  the 
scale.  \\hen  the  resistance  of  the  selenium  cell  is  lessened  by  exposure 
to  the  .r-ray  the  millianiperemeter  registers  an  increased  current.  The 
selenium  cell  is  set  at  a  point  near  the. r-ray  tube,  and  the  battery, 


1  !."><) 


MKDICAL    KLKCTHICITY    AND    KONTCKX    KAYS 


resistance,  and  inilliamperemoter  may  bo  al  a  distant  position,  whore 
the  operator  may  be  protected  from  the  .r-ray  by  the  interposition  of  a 
brick  wall  it'  this  is  desired.  Any  change  in  the  amount  of  current 
registered  bv  the  niillianiperenieter  would,  of  course,  indicate  a  fluctua- 
tion in  the  amount  of  ./'-ray  being  generated  by  the  lube,  ami  would 
cause  the  operator  to  take  the  necessary  steps  to  regulate  the  tube. 
The  use  of  the  apparatus  as  a  measurement  of  dosage  is  more  or  less; 
empiric.  The  selenium  cell  is  set  at  a  certain  di-'ancc  from  the  .r-ray 
tube  and  the  amount  of  deviation  produced  in  the  milliamporemeter 
is  noted.  A  Sabouraud  and  Noire  tablet  for  radiomet  ry  or  a  Holxknooht 
tablet  is  exposed  for  the  time  necessary  to  produce  a  specified  number 
of  Hol/kneeht  units.  This  furnishes  a  scale  from  which  the  operator 
can  judge  of  the  number  of  units  or  fraction-;  of  units  applied  in  any 
number  of  minutes.  It  is  necessary  to  place  the  selenium  cell  at  the 
same  distance  as  in  determining  the  standard,  and  to  regulate  the  in- 
tensity of  the  .r-ray  so  that  it  will  produce  the  standard  deviation  in  the 
milliamporemeter,  and  then  expose  the  patient  for  the  necessary  num- 
ber of  minute-  to  produce  the  required  dosage. 

Boi'il/t  /•'.<  I 'nit  I.  It  is  the  amount  of  .r-ray  which,  acting  upon  a 
2  per  rent,  solution  of  iodoform  in  chloroform,  the  rays  being  normal 
to  the  surface  -the  surface  being  1  square  centimeter  and  the  depth  1 
centimeter-  will  liberate  ,',,  milligram  of  iodin. 

'.->.')  I  is  about  equal  to  5  II.  1 5  Holxknecht  unit-;. 

I>nr<li<'r'x  Railionictric  Thitx. — These  depend  upon  the  change  in 
color1  undergone  by  barium  platinocyanid  at  half  the  distance  from  the 
ant  icat  hodo  to  the  skin. 

l>i>r'li<r'x  tint  1  'clear  yellow;  equals  21.  'I  equals  the  quantity  of 
.r-ray  which  will  liberate  ,',,  milligram  of  iodin  in  1  cc.  of  Ground's  solu- 
tion. The  latter  is  a  2  per  cent,  solution  of  iodoform  in  chloroform 


and   become-  red  when    exposed   to  the  .r-ray.      His  //'///   .•*  'sulphur  yel- 
equal-:;1,    I.       Hi-  tint.}  fuambogej  equals  .V,    1.       Hi-  tint  .'/    (c'hest- 

1     . '      '';.•-     |U   I. 

-"//'///'.    lf<itlif>fjh/>foni('tr>c  Miffioil.    -This  consist s  in  a  method 
i*-1  '    I  he   illumination    produced    in   a    barium    platinocyanid 

creei  it  of  ordinary  light  of  different   candle-powers. 

\Jiilmil  nf  It/nliti/t/i  //•//.  This  i-  in  (leiermine  by  \'olume 
the  anio  r.'  alomel  precipitated  from  a  solution  of  ammonium  oxa- 
late  and  'hloi'iil  wheti  exposed  to  the  .r-ray. 


EtOXTOEXOTHERAPY  1  1  ")/ 

Caxtex  modifies  Schwartz's  method  by  taking  the  weight 'of  the  pre- 
cipitate instead  of  its  volume. 

Cnrchod's  Method  of  x-/\'(ty  Dosage  by  a  Voltameter  rti  the  Secondary 
Circuit.1 — The  instrument  is  like  a  pipet  containing  15  cc.,  but  with 
its  lower  end  bent  up  so  as  to  hold  about  10  cc.  The  latter  is  open 
at  the  top.  .Platinum  wires  allow  the  secondary  current  to  pass  through 
the  acidulated  water  in  the  closed  arm  of  the  pipet,  and  bubbles  of 
mixed  hydrogen  and  oxygen  gas  tire  liberated  and  accumulate  at  the 
top.  The  number  of  cubic  millimeters  of  gas  liberated  while  a  Sabou- 
raud  and  Xoire  barium  plat inocyanid  pastil  is  changed  to  tint  B 
affords  a  unit  which  may  be  subdivided  at  will  for  future  treatments 
without  having  to  use1  the  pastil  each  time,  and  it  is  useful  by  giving 
smaller  fractions  than  the  Sabouraud  and  \oire  method. 

liiraonu's  Aelinomcicr. — This  is  an  instrument  for  measuring  the 
intensity,  in  actinic  rays,  of  the  various  lights  used  in  phototherapy 
and  also  of  the  x-ray.  A  hollow  metal  cylinder  has  an  opening  at  OIK; 
end  which  fits  closely  over  the  observer's  eye  and  at  the  other  end  a  disk 
half  of  which  is  opaque  and  black,  the  other  half  being  coated  with 
barium  platinocyanid.  This  end  of  the  tube  is  closed  by  a  sheet  of 
quart/  crystal,  and  the  whole  tube  is  moved  back  and  forth  by  means  of  a 
rack  and  pinion  in  the  dark  box  which  surrounds  it.  This  box  is  filled 
with  a  solution  consisting  of: 


Opposite  the  end  of  the  tube  there  is  a  quartz  window  4  cm.  in  di- 
ameter. The  light  to  be  tested  passes  through  this  window,  through 
the  liquid,  and  through  the  quart/  window  at  The  end  of  the  tube, 
and  produces  a  greater  or  less  fluorescence  in  the  barium  platinocyanid 
at  that  point.  The  solution  with  which  the  box  is  filled  absorbs  the 
actinic  rays,  and  if  the  layer  of  liquid  is  thick  enough  it  will  entirely 
prevent  the  visible  fluorescence  of  the  barium  platinocyanid.  In  apply- 
ing the  test  the  actinometer  is  held  at  a  distance  of  2  meters  from  the 
source  of  light,  and  the  tube  is  moved  back  and  forth  in  the  box  so  as  to 
measure  the  thickness  of  liquid  required  to  suppress  the  fluorescence. 

Tested  in  this  way  an  arc  light  for  phototherapy  (current  of  110 
volts.  20  amperes)  suffered  absorption  of  all  its  actinic  rays  by  5X.5 
mm.  of  the  solution;  a  large  arc  lamp  for  stereopticon  purposes  with 
vertical  carbons  (110  volts,  20  amperes),  by  55.5  mm.;  a  small  arc 
lamp  for  the  stereopticon  (110  volts,  7  amperes),  by  42.5  mm.;  the  direct 
rays  of  the  sun  at  4:^0  p.  M.  in  July,  by  70.5  mm. 

This  method  is  applicable  to  all  varieties  of  phototherapy,  including 
the  ultraviolet  ray  from  (leissler  tubes.  It  has  not  yet  been  deter- 
mined whether  this  furnishes  a  reliable  guide  to  the  comparative  in- 
tensity of  the  .r-ray,  but  it  certainly  seems  less  convenient  than  the 
ordinary  radiometer  dependent  upon  the  thickness  of  a  metal  which 
the  .r-ray  will  penet  rate.  This  is  indicated  upon  a  barium  platinocyanid 
screen  or  upon  a  photographic  plate  in  the  cases  in  which  it  is  desired 
to  produce  an  indisputable  record  of  the1  penetrating  quality  of  the  ray 
employed  in  making  a  radiograph.- 

1  Arch.  d'Hlec'tric-ito  Mc'liralc,  Jan.  10.  1907. 
-  Ihi-L.  Bordeaux,  France,  Jan.  1.1,  UK):]. 


1158  MEDICAL    ELECTRICITY    AND   RONTGEN    RAYS 

Kienbock'x  Qtiantitometer  for  Measuring  x-Ray  Doxage. — The  appa- 
ratus used  by  this  Vienna  radiologist1  employs  little  .slips  of  not  very 
sensitive  bromid  paper  of  a  standard  make.  One  of  these  is  wrapped 
in  black  paper  and  exposed  at  the  same  time  and  distance  as  the  patient; 
then  it  is  placed  in  a  developing  solution  of  standard  strength  for  a 
standard  time  (one  minute)  inside  a  little  portable  dark  room.  The 
developed  paper  is  at  once  compared  with  a  scale  of  different  shades  of 
paper.  The  number  marked  on  the  shade  which  the  test  paper  matches 
indicates  the  number  of  Kienbock  units  applied.  Kach  unit  is  called 
"x."  and  is  equal  to  A  11..  so  that  this  method  is  twice  as  delicate  as  the 
Hnl/knecht  method.  The  developing-box  is  just  large  enough  for  the 
hands  to  work  inside  of.  a  dark  sleeve  being  fastened  around  the  wrist 
to  exclude  ordinary  light.  Kuby  glass  windows  admit  red  light  and 
allow  the  operator  to  see  what  lie  is  doing.  Possible  sources  of  error 
are  a  change  in  the  sensitiveness  of  the  paper  from  age  or  atmospheric 
conditions  and  a  change  in  the  activity  of  the  developing  solution. 

Milton  Franklin  $  electroscope  for  the  dosage  of  the  x-ray  consists 
of  a  delicate  electroscope,  which  may  be  placed  at  a  measured  distance 
from  the  tube.  The  electroscope  is  first  charged  and  the  rapidity  of 
discharge  is  noted  by  means  of  a  magnifying  glass.  A  circular  metal 
disk  forms  a  shield  for  the  operator. 

The  labour  and  and  Xoire  Radiometer. — This  is  described  more  fully 
on  p.  1181.  A  little  tablet  coated  with  barium  platinocyanid  is  exposed 
at  half  the  distance  from  the  anticathode  to  the  surface  to  be  treated 
during  the  x-ray  application.  When  the  original  apple-green  color  has 
changed  to  tint  B,  a  brownish  yellow,  a  full  dose  of  5|  Holzknecht's 
units  has  been  applied. 

The  Hampson  radiometer  has  a  colored  scale  of  25  tints  with  which 
an  exposed  barium  platinocyanid  pastil  is  compared,  4  E  at  skin  distance 
equals  Sabouraud  tint  B  or  about  5  H  (Holzkneeht  units.) 

The  Lovibond-Corbett  tintometer  is  a  device  for  accurately  estimat- 
ing the  coloration  of  a  Sabouraud  and  Noire  pastil. 

It  has  been  stated-  that  doubling  tiie  voltage  (without  changing  the 
amperage)  results  in  only  doubling  a  Holzkneeht  pastil  reaction,  while  it 
quadruples  the  photographic  effect.  Within  certain  limits  this  is  ap- 
proximately correct;  and  the  effect  upon  the  skin  is  only  doubled  while 
the  deep  effect  is  quadrupled.  With  the  doubled  voltage  the  x-rays 
possess  four  times  more  energy  and  are  more  penetrating  and  less  ab- 
sorbable.  The  effects  of  all  kinds  are  proportional  to  the  energy  of  the 
ray-  reaching  1  he  specified  object  and  to  t  he  quantity  of  energy  absorbed 
by  t  he  object . 

I/are/'*  Carrii-r  for  the  Sabouraud  and  Xn/rt  [Radiometer*  This  ap- 
paratus (Fig.  810)  is  employed  by  the  author  and  is  made  of  hard  rub- 
ber and  i-  damped  to  the  x-ray  tube  near  the  cathode.  It  carries  one 
of  the  Sabouraud  and  Xoire  tablets,  which  may  be  adjusted  at  half  the 
di-tance  from  the  aiitieathode  to  the  patient,  and  also  a  dark  brownish- 
yellow  tablet  for  comparison.  During  the  exposure  the  radiometer 
tablet  i-  protected  from  ordinary  light  by  a  sheet  of  black  paper,  but 
occasionally  the  tablet  may  be  turned  back  for  comparison  with  the 

1  I.'     ll'i'l.-im.   April.   I'HMl.  p.   1'J.I. 

-Am'T.  Jour.   Klcrt  rotlicrapriitics  jind   Radiology,  vol.  xxxvi,  No.  1,  Jan.,   101S, 

p.  :;i. 

3  Arch.  il'Klc.-trintc  M<.,lic;i!c,  Jan.  10,  190.1 


RONTGENOTHERAPY 


1159 


tost  object.  When  it  has  turned  the  same  dark  yellow  color  as  the  latter 
it  is  called  tint  II,  which  means  that  a  full  therapeutic  dose  has  been 
applied,  causing  all  the  hair  of  the  scalp  to  fall  out  from  a  single  treat- 
ment. This  is  equal  to  f^  Ilolzknecht  units. 

It  is  supposed  to  be  necessary  only  to  simply  continue  the  exposure 
to  the  x-ray  until  the  test  object  has  undergone  the  standard  chemic 
change  as  indicated  by  its  color.  Practically,  it  is  found  that  a  variety 
of  conditions,  atmospheric  and  otherwise,  render  it  difficult  to  apply 
these  methods  every  time  the  x-ray  is  turned  on.  At  the  same1  time,  these 
methods,  applied  under  ideal  laboratory  conditions,  are  excellent  for 
use  in  standardizing  other  more1  practicable  methods  of  dosage. 

The  practical  object  to  be  sought  is  a  means  of  measuring  the  in- 
tensity of  the  radiation  in  terms  from  which  one  may  in  an  instant 
calculate  the  duration  of  exposure  at  a  given  distance  required  to 


Fi«.  SlO. — Haret's  carrier  for  the  Sabouraud  and  Xoirc  radiometer. 

produce  a  certain  effect  on  the  tissues  if  rays  of  a  certain  quality  are 
employed. 

x-Ray  Doxayc. — For  Rontgen  therapy  as  well  as  for  radiography 
an  entirely  satisfactory  and  universally  available  method  is  to  regulate 
the  apparatus  so  that  it  will  apply  rays  corresponding  to  a  certain  spark 
length  or  resistance  or  voltage  and  a  certain  milliampcrage,  either 
through  a  certain  filter  or  not,  for  a  certain  length  of  time  and  at  a  cer- 
tain distance.  With  the  Coolidge  tube  and  a  modern  transformer 
outfit  these  factors  are  easily  controlled.  Any  operator's  determination 
of  the  factors  required  to  produce  a  certain  physiologic  effect  may  be 
by  reading  authoritative  statements  as  to  dosage,  and  in  this  case  it  is 
most  important  to  be  sure  that  one's  technic  is  correct,  especially  as  to 
the  voltage  or  spark-gap  represented. 

Or  the  individual  operator  may  test  the  dosage  himself  by  keeping 
accurate  records  of  the  factors  employed  in  each  application  and  of  the 
results  therefrom.  This  method  usually  requires  some1  approximate 


1160 


MEDICAL    ELKC'TRK'ITY    AND    RONTGEN    RAYS 


guide  in  the  beginning  cither  from  the  experience  of  others  or  from  some 
direct  method  of  measurement  of  the  radiation  itself.  Or  the  operator 
may  adjust  his  apparatus  for  the  desirable  factors  of  voltage  or  spark 
and  milliamperage.  and  then  by  means  of  an  ionization  chamber  or  of 
barium  platinocyanid  pastils  or  of  photographic  paper  determine 
the  time  required  to  produce  a  Sabouraud  or  Kicnbock  or  similar  unit 
of  .r-ray  dosage.  It  would  be  wise  to  make  such  a  determination  re- 
peatedly to  overcome  sources  of  error  and  finally  to  use  the  electric 
and  time  and  distance  factors  for  actual  treatments.  These  are  more 
uniformly  reproducible  than  any  dose  involving  the  direct  measurement 
of  the  radiation  for  each  treatment. 

With  modern  apparatus  the  author's  unit  of  the  intensity  of  the 
.r-ray  is  no  longer  required. 

Kxample  of  erythema  dose  of  hard  .r-ray s:  In  treating  a  recurrent 
malignant  tumor  of  the  intestine  the  author  used  a  3  mm.  aluminum 
filter  and  the  anticathode  was  10  inches  from  the  skin.  His  generator 
of  a  con-taut  high  voltage  was  used  with  a  parallel  spark  resistance  of 
~)'l  inches  and  the  current  was  3  ma.  Each  exposure  was  ten  minutes 
for  successive  quadrants  of  the  abdomen,  shielding  the  others  with  lead 
about  \  inch  thick.  The  same1  area  was  exposed  at  intervals  of  three 
weeks  and  the  second  exposure  was  followed  by  transitory  sensation 
with  scarcely  any  change  in  the  appearance  of  the  skin. 

This  is  exactly  the  author's  teclmic  for  deep  therapy  when  the  same 
area  is  to  be  exposed  at  intervals  of  three  weeks  or  more. 

He  makes  the  time  possibly  50  per  cent,  longer  when  only  one  ap- 
plication is  to  be  made  to  the  same  area. 

T<>ux(-ii  r/a'/N  <>f  .I'-h'iti/  Power  and  Quantity.—  1  Touxcu  is  the  .r-ray 
power  which  will  produce  upon  kodak  photographic  film  an  effect  equal 
to  that  of  1  candle-power  of  carbon  filament  incandescent  electric  light 
of  the  usual  brightness,  applied  for  the  same  time  and  at  the  same  dis- 
tance. Different  films  and  plates  present  different  ratios  of  sensitive- 
ne-s  to  light  and  the  .r-ray.  Kodak  film  is  selected  because  universally 
obtainable.  It  is  equal  to  0-inch  spark  and  .10  ma.,  or  to  6-inch  spark 
and  100  ma.,  or  4-inch  spark  and  200  ma. 

1  TUHXCII  uictcr  xccond  is  the  quantity  of  the  .r-ray  which  will  produce 
upon  kodak  photographic  film  an  effect  equal  to  that  of  1  candle-power 
of  carbon  filament  incandescent  electric  light  applied  for  one  second  at 
a  di.-taiice  of  1  meter. 


ition  =  1  II. 

it  ion   =  ">.\  II. 

ition  :    Tint  B.  Sabouraud  and 

NoirtS. 

ition        Tint   1  Bordicr. 
ition   -   '.'>  or  -1  units  I  Bordicr- 

( ialinmrd. 
ition        (i2.r)  Ciuilh'ininot    units. 

M. 

it  ion        10  X  i  Kionbock), 
it  ion         •'>..">  kalonis  (Srli\vart  /  ' . 
ition        An  ordmarv  crvthcina 


RONTGENOTHERAPY 


1101 


This  is  a  valuable  means  of  gauging  the  intensity  of  the  .r-nty,  and 
so  determining  its  safety  limit  and  the  exposure  required  to  make  a  pic- 
ture in  radiography  and  its  dosage  in  therapeutics. 

.  1  ji/>l/c(itioti  of  ////N  Mdhoil  l<>  Secure  Nc//r///  ///  Radiotfra  [thij.—  The 
radiographer  should  measure  the  intensity  of  the  radiance  which  he 
habitually  uses  for  certain  classes  of  work.  If  this  is  of  1  Tousey  power, 
then  .")()()  meter  seconds  (or  fifty-five  seconds  at  ]  meter  from  the  anti- 
cathode  to  the  skin)  would  lie  an  erythema  dose.  This  exposure  at  one 
time,  or  divided  among  several  radiographs  within  a  week  or  two,  would 


DR.S.TOUSEY 


produce  an  .r-ray  burn.  If  one's  technic  is  so  poor  or  the  subject  so  diffi- 
cult that  the  examination  cannot  be  completed  without  approaching 
this  s.-ifcty  limit,  the  attempt  should  be  abandoned. 

.(•-Rav  of  1  Toiisev  power  will  make  most  radiographs  in  a  fraction 
of  a  second  with  or  without  an  intensifying  screen,  depending  upon  the 
i lifficulty  of  the  case, 

77"  THII.^I  i/  Mi  t/inil  nf  l)dsii'i<  >n  L'ii/ifi!<  not/it  rn />>/.-  For  surface  lesions 
no  tilterinu'  sci'een  is  used  eith.er  for  previously  measuring  the  Tousey 
pow<  r  with  a  kodak  film  or  during  the  treatment.  If  the  .c-radiance  lias 


1102  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

Erythema  Exposures  vf  x- liny  of  Various  Rndiographic  Strengths. 


Antieathuile  to  Skin. 

Meters.                          Inches. 

13 

56 

6                                                   ''-1' 

14 

' 

13 

2  4 

i 

til 

42 

13 

52 

1 

64 

14 

| 

13 

<)j 

6 

til 

2  ' 

1 
3 

13 

18! 

*                                                   G" 

4, 

an  erythema  dose  of  500  Tousey  meter  seconds.     Other  distances  and 
their  erythema  doses  are  given  in  the  following  table: 

Erythema  l)nx<  of  x-Rny  in  Ordinary  Therapeutic  Strength. 


I  H-tanfe  fro 

tO  r 

11  antirathtxle 
kin. 

'1'ousey  power. 

Six-inch 
spark.  Ma. 

Four-inch 

spark,  Ma. 

Minutes. 

Meters. 

Inehw. 

13 

1  /()() 

14 

3 

56 

- 

13 

1   50 

2 

4 

47 

13 

1/40 

21 

5 

37 

13 

1/30 

34 

6| 

28 

9  3 

1  /'()() 

14 

3 

31 

94 

1/50 

2 

4 

25 

94 

1/40 

21 

5 

20 

9! 

1/30 

3f 

6§ 

15 

8 

1/60 

14 

3 

20 

s 

1  /50 

2 

4 

16! 

s 

1    40 

2.  I 

5 

134 

i 

8 

1  /30 

3  , 

61 

10 

i 

6| 

T>0 

u 

14 

ji 

6J 

50 

111 

i 

til 

40 

94 

i 

til 

30 

7 

i 

5  i 

IK) 

10 

i 

51 

50 

S| 

i 

5.1 

10 

61 

i 

5.1 

/30 

5 

i 

4; 

/tiO 

8 

4; 

/50 

61 

i 

4; 

1     10 

54 

i 

4; 

1    :•!() 

4 

i 

I1, 

1    tiO 

6 

i 

1  1 

1    50 

5 

!{ 

1     10 

4 

: 

45 

1    30 

3 

1'nu.i,,  1'nii-i  r  of  thi  .r-lttii/ front  \'<tr/onx  (it  m-rntnr*.-  A  1 2-inch  induc- 
tion-roil, \\-jt  1:  ;i  wheel  interrupter  and  a  primary  current  of  110  volts 
and  .">  ampere-  ,-ind  a  -ecoTidary  current  of  11  ma.,  produces  an  x-ray  of 

about     ,.',,    ToU-e\'. 


RONTGENOTHERAPY 


1163 


~  •— 


o 


O     i 


c 
- 


*T:  —    T.  ~   ~  "'  w 

5-5  ~~    -  "^ 

i'>.H.^=        ^ 


t.     X  t_ 


Ilti4  MEDICAL    ELECTRKTTY    AXD    RONTCJEX    KAYS 

The  same  coil,  with  a  Wchnolt  interrupter  and  a  primary  current  of 
110  volts  and  IS  amperes  and  a  secondary  current  of  S  ma.,  produces  an 
.r-ray  of  about  ^  Tousey. 

A  static'  machine  actuated  by  a  current  of  220  volts  and  25  amperes 
and  sending  about  ('•>]  ma.  through  the  .r-ray  tube  produces  an  .r-ray  of 
about  i  Tousey  power. 

An  interrupterless  transfonner  or  a  high-tension  direct  current  gene- 
rator produce  from  ,1  to  1  Tousey  for  radiographic  work,  and  may  be 
reduced  to  ,;',,  Tousey  for  treatment  or  Huoroscopy. 

Modern  apparatus,  such  as  the  Coolidge  tube  and  the  transformer 
and  the  oscilloscope,  make1  it  entirely  ]>ossible  to  produce  rays  corres- 
ponding exactly  to  a  specified  spark  length  and  milliamperage  free 
from  inverse  discharge.  And  with  these  factors  secured  the  dosage 
may  be  accurately  stated  as  so  many  milliampere  seconds  with  such 
-park  equivalent  (or  such  a  voltage  if  you  are  sure  of  your  voltmeter), 
at  such  a  distance  and  with  or  without  such  a  filter. 
This  is  now  (1920)  the  method  of  choice. 

ViUdril'*  Instruments  for  Measuring  the  Intensity  and  Quality  of  the 
x-R<i]i. — These1  depend  upon  the  ionizing  effect  of  the  ray.  The  radio- 
sclerometer  is  of  the  nature  of  a  quadrant  electrometer,  which  is  con- 
nected with  a  source  of  uniform  potential,  such  as  a  direct  110-volt 
of  electric-light  circuit.  The  .r-ray  can  reach  different  parts  of  the  ap- 
paratus through  an  aluminum  and  a  silver  screen.  The  deviation  of  the 
electrometer  indicates  the  ratio  between  the  radiation  transmitted  by 
the  silver  and  by  the  aluminum.  This  is  dependent  upon  the  quality  of 
the  ray  and  not  upon  its  intensity. 

The  radioquantitorneter  registers  by  clockwork  the  number  of  times 
that  an  electroscope,  connected  with  the  110-volt  direct  current,  becomes 
charged  and  discharged  during  the  total  time  that  the  patient  is  exposed 
To  the  .r-ray.  The  electroscope  in  this  case  is  of  the  general  construction 
of  a  quadrant  electrometer. 

Kach  of  these  two  instruments  looks  like  a  milliamperemeter,  and 
is  intended  to  be  placed  at  the  same  distance  from  the  .r-ray  tube  as  the 
patient. 

Influence  of  the  Rate  of  Interruption  in  the  Primary  Current 
Upon    the    Quantity    of    x-Ray    Produced. — In   an   experiment    by 
ier,1    with    the   same   strength   of  primary    current    and   the   same 
ity  of  .r-ray,  the  Sabouraud  and  Xoin'  radiometer  absorbed  1  lint 
ineteen  minutes  with    1!KJX  interruptions  per  minute;  and  required 
ten  and  a  half  minutes  when  the  interruptions  were  at  the  rate  of 
•  minute. 

has  a  very  important  bearing  upon   the  subject   of  dosage  in 
rapy.      It  doe-  not  impair  the  value  of  any  of  the  measurements 
•pend  upon  the  change  produced  in  a  chemic  substance,  but   it 
>•<•!    measurements   based,   like   the  author'-,  upon  brilliancy  of 
':•>::.  or.  like  Johnston's,  upon  the  resistance  of  a  selenium  cell. 
'.'M   methods  and  several    others  might    give   different    results 
types  of  apparatus  .-ending  impulses   through   the  .r-ray 
•  ;  i !    rat  es  per  minute. 

the  .''//••>  imirhhn   for  ./'-ray  treat  merits  is  entirely  satis- 
H       '    m;i'-hine  is  powerful  enough  and  in  good  working  order. 
Arch.  d'Klcctriciti'  Mrdic;de,  .Ian.  10,  1907. 


RONTGENOTHERAPY  1  l()f> 

Measured  by  ;i  milliamperemeter  the  current  passing  through  the  lube 
will  be  found  not  to  be  much  over  1  or  '2  ma.  at  the  most,  ami  the  fact 
that  tlie  amperage  is  very  lo\v  makes  the  healing  of  the  ant  icathode 
very  slight.  In  fact,  1  he  heat  is  dissipated  as  last  as  it  is  produced, 
and  so  the  bulb  may  be  used  for  hours  without  getting'  hot  and  without 
material  change  in  decree  of  vacuum.  Jt  is  on  this  account  that  tin- 
less  expensive?,  but  equally  well  made,  light  anlicathode  tube-  are  used 
with  t  he  stat  ic  machine.  The  small  amount  of  current  passing  through 
the  tube  causes  the  intensity  of  the  ray  to  be  so  slight  that  much  longer 
exposures  are  required  than  with  a  coil.  Jvxperience  in  radiograph v 
Allows  thai  t  he  1  in ie  must  be  about  five  t  nnes  as  long,  and  in  fluoroscopv 
the  safe  t  ime  of  exposure  is  so  long  1  hat  t  here  is  danger  of  forget  t  ing  1  hat 
t  here  i<  a  limit  beyond  which  1  here  is  the  risk  of  a  burn.  In  radio!  herapy 
with  the  static  machine,  in  the  absence  of  special  apparatus,  like  Ilol/- 
knecht's  chromoradiometer,  the  dose  which  may  be  administered  every 
two  oi1  three  days  may  be  Mated  to  be  eight  to  lifleen  minutes  at  a  dis- 
tance of  10  inches  from  the  anticathode.  This  is  with  a  machine  having 
twelve  or  sixteen  revolving  glass  or  mica  plates,  i>'2  inches  in  diameter, 
and  with  a  t  ube  of  medium  or  hi.irh  vacuum,  backing  up  a  spark  of .'!  to  o' 
inches.  Spark-gaps  are  generally  useful  when  working  with  a  -tatic 
machine. 

THE   -V-RAY  IN  THE  TREATMENT   OF  MALIGNANT  DISEASE 

'I  he  ./--ray  most  assuredly  has  a  selective  action  upon  the  atypic, 
rapidly  developing  cells  which  constitute  the  essential  part  of  most 
malignant  neoplasms.  There  is  reason  to  believe  that  tne  soft  rays. 
those  with  the  least  penetrating  power,  produce  the  most  beneficial 
.  and  it  is  very  certain  that  the  disease-,  like  epithclionui.  in  which 
the  lesion  is  ofien  a  purely  surface  one.  an1  much  more  amenable  to  this 
method  of  treatment  than  are  the  carcinomata  and  the  sarcomata  with 
deep-seated  lesions.  Still,  even  these  are  almost  always  favorably 
a !'ii rted.  and  in  some  case-  a  cure  may  be  produced.  The  effect  generally 
.-ought  is  not  one  of  destruction  <  n  tndxxc,  but  of  molecular  change  and 
elimination.  It  is  seldom  wise  to  produce  an  ulceration  by  the  applica- 
tion of  i  he  ./'-ray  in  treating  malignant  disease.  In  some  cases  the 
elimination  of  the  products  of  a  degenerative  process  produced  by 
./•-ra  v  t  reat men!  of  a  large  malignant  growth  will  cause1  a  .-ort  ol  toxemia. 
This  is  a  temporary  mat  ter  and  its  nai  ure  is  discussed  in  the  chapter  on 
the  phvsiologic  effects  of  the  .r-ray.  It  mav  furnish  an  indication 
for  less  vigorous  treatment  for  a  tune;  it  doe-  not  indicate  a  tendency 
on  [lie  part  of  the  treatment  to  produce  metastases  and  a  general 
dissemination  of  the  disease.  The  latter  question  has  been  most  thor- 
oughly studied.  In  certain  cases  which  are  submitted  to  .r-ray  treat- 
ment while  the  disease  is  still  purely  local,  and  before  any  metastases 
have  taken  place,  the  x-ray  effects  either  an  actual  or  a  symptomatu 
cure.  In  other  cases  metaslase-  have  already  occurred  and  may  some- 
time- be  demonst rated  by  .r-ray  examination  m  the  mediastinal  glands, 
although  symptoniatically  the  disease  may  still  appear  to  be  a  local  one. 
In  such  a  case  .r-ray  treatment  ma\  produce  a  brilliant  effect  upon  tin 
li  sion,  and  this  mav  be  accompanied  by  a  most  gratifying  increase 
in  health  and  strength.  Then  after  a  period  of.  it  may  be,  seemingly 
perfect  health  lasting  for  several  months,  the  patient  shows  evidence 


llOt)  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

of  the  systemic  involvement,  and  a  fatal  termination  very  quickly  ensues. 
In  such  cases  the  .r-ray  has  not  caused  the  dissemination  of  the  disease, 
it  has  simply  been  unable  to  prevent  it.  Much  benefit  may  be  accom- 
plished in  such  cases  in  the  direction  of  removing,  controlling,  or  pre- 
venting the'  recurrence  of  a  local  lesion  and  delaying  the  occurrence  of 
metastases  and  death,  and.  except  for  intrathoracic  and  intra-abdominal 
cancers,  a  considerable  percentage'  of  cures  may  be  expected.  A'-ray 
treatment  before  and  after  an  operation  upon  an  external  growth,  such 
as  a  carcinoma  or  sarcoma  of  the  breast,  has  a  decided  tendency  to  pre- 
vent recurrence.  The  same  holds  good  of  cancers  of  the  neck  of  the 
uterus,  a  part  which  can  be  reached  directly  by  the  .r-ray,  but  here 
internal  involvement  has  practically  always  occurred  before  .r-ray 
treatment  is  begun.  Valuable  and  effective  as  it  is  in  these  cases  it 
will  probably  not  save  the  patient's  life.  The  beneficial  effects  of  the 
.r-ray  in  cancer  are  the  relief  of  pain  by  an  immediate  action,  the  cure  or 
control  of  a  local  lesion,  a  directly  beneficial  effect  upon  the  general 
health,  the  prevention  of  recurrence  if  internal  involvement  is  not  al- 
ready present,  and  the  cure  or  control  of  external  glandular  metastases. 
A'-ray  treatment  is  indicated  at  every  stage  of  a  cancer,  but  it  should  be 
an  adjunct  to  and  not  a  substitute  for  surgery  in  the  majority  of  cases. 
The  technic  consists  in  exposing  not  only  the  affected  region,  but  a 
considerable  surrounding  area,  to  the  rays  from  a  tube  with  a  low 
vacuum  ('resistance  3  inches)  or  preferably  a  high  vacuum  for  surface 
lesions,  and  a  high  vacuum  (resistance  0  inches)  for  those  more  deeply 
seated.  It  is  absolutely  necessary  to  produce  a  certain  degree  of  reaction, 
but  probablythe  best  results  are  obtained  when  this  occasions  only  redness 
and  a  dry  desquamation  without  uleeration.  Cases  of  deep-seated  cancer, 
as  of  the  breast,  in  which  the  disease  has  not  produced  uleeration,  are  as 
amenable  to  the  influence  of  the  .r-ray  as  cases  in  which  uleeration  has 
occurred.  The  same  two  methods  are  available  for  cancer  that  are  used 
f or  other  cases.  By  one  method  moderate  doses  (nine  minutes  at  10  inches 
from  theanticathode,  with  an  intensity  which  shows  the  bones  of  the  hand 
faintly  at  2  feet;  or  \Vehnelt  interrupter  with  tip  of  platinum  I  mm.  in 
diameter  exposed,  primary  current  1  amperes,  current  through  .r-ray 
tube  1  or  2  ma.,  six  minutes  at  a  distance  of  10  inches  from  the  anti- 
'•athode;  or  static  machine  with  twelve  revolving  plates  '.]()  inches  in 
diameter,  ten  minutes  at  a  distance  of  10  inches  from  the  anlicathode) 
are  iriven  about  every  three  days.  Or,  preferably,  li-inch  spark,  10-inch 
di-t a i ice,  12( '  m ill iampere  seconds  without  a  filter  or  210  m.  s.  with  o  mm. 
aluminum.  The  development  of  the  desired  reaction  is  gradual  and  the 
dosm'e  mav  be  regulated  accordingly.  Treatment  is  usually  continued 
for  a  li'iod  many  months,  possibly  making  complete  intermissions  from 
The  other  method  involves  the  administering,  either  at 
a  If  doses,  of  a  sufficient  amount  of  .r- radial  ion  to  produce 
leuree  ()f  reaction.  The  amount  is  m  terms  of  IIol/- 
oradiometer,  and  i-  1  II.,  •>  H.,  or  even  more  in  certain 
But  the  working  direction-  are  about  (100  ma.  seconds  at  10 
with  a  li-inch  -park  and  no  filter.  Or  1200  ma.  seconds  with  :> 
it  aluminum.  The  application  should  not  be  repeated  until  after 
•velopmeiit  and  subsidence  of  the  reaction.  This  will  take  from 
to  MX  weeks.  _\  standard  Coolidge  tube  or  a  water-cooled  or 
ded  ua--tiiled  lube  are  excellent  for  this  purpose.  A  locali/ing 


RONTGENOTHERAPY  1167 

shield  is  a  desirable  means  of  protection  for  the  operator  and  the  patient 
in  the  treatment  of  most  cases. 

With  some  apparatus  a  primary  current  of  2  or  3  amperes  and  12 
volts  is  suitable  for  therapeutic  work,  while,  with  others  a  primary 
current  of  from  o  to  10  amperes  and  from  (>()  to  90  volts  is  required. 
The  different  elements  that  go  to  produce  the  x-ray  are  so  complex 
and  mutually  dependent  that  the  only  universal  measure  of  efficiency 
and  dosage  is  in  the  radiance  itself. 

The  number  of  milliamperes  actually  passing  through  the  tube 
furnishes  a  guide  of  considerable  value,  though  it  does  not  dispense  with 
Hie  other  considerations.  About  3  ma.  passing  through  a  tube  with 
a  resistance  of  (>  inches  usually  produces  at  a  distance  of  10  inches  a 
normal  dose  of  ',  II  in  one  minute.  This  normal  dose  is  the  radiation 
which  may  be  repeated  every  two  or  three  days  until  a  reaction  gradually 
becomes  established. 

d'<i/j]'e'x,  Snook' x,  or  Wcxton'x  miUiamperemeter,  showing  exactly  the 
amount  of  current  passing  through  the  .r-ray  tube,  is  valuable  in  con- 
nection with  the  other  factors  which  go  to  the  production  of  the  .r-ray, 
especially  the  spark  equivalent.  Taken  by  itself  it  does  not  furnish  a 
reliable  guide. 

If  a  large  region  is  to  be  treated,  the  full  number  of  units  may  be 
applied  to  different  portions  one  after  another.  Within  reasonable 
limits  the  .r-ray ing  of  several  different  parts  of  the  extremities  on  the 
same  day  does  not  produce  an  undesirable  effect,  but  it  is  especially 
necessary  to  limit  the  application  so  that  adjacent  parts  will  not  receive 
a  double  dose.  Further  details  about  safe  and  dangerous  doses  have 
been  given  in  the  article  on  rr-Kay  Dermatitis. 

The  author  has  been  consulted  about  a  case  where  a  general  appli- 
cation of  the  .r-ray  to  the  hand  for  multiple  warts  was  followed  by  tJie 
necessity  for  amputation. 

If  a  transformer  is  used  instead  of  an  induction-coil  the  primary 
current  should  be  turned  on  sufficiently  to  produce  a  current  of  '2  or  3 
ma.  through  a  tube  with  a  (i-inch  resistance.  This  form  of  appara- 
tus riMiuircs  no  interrupter  and  works  on  an  alternating  circuit.  The 
x'coiidary  current  is  absolutely  steady,  and  perhaps  this  is  the  best 
apparatus  yet  devised.  It  is  described  in  detail  on  p.  748.  Hither  a 
gas-filled  or  an  electron  discharge  tube  like  the  standard  Coolidge  tube 
may  be  used. 

The  harder  the  rays  or  the  greater  the  resistance  of  the  tube,  the 
ureater  number  of  Ilolxknecht  or  of  Kienbock  units  the  >kin  will  stand. 
But  this  does  not  mean  a  greater  number  of  millianipere  seconds. 
Ordinarily  for  dee])  radiotherapy  a  filter  >uch  as  o  mm.  of  aluminum  is 
ii>ed  t<>  shield  the  skin  from  rays  which  could  not  penetrate  the  su- 
perficial tissues  and  affect  the  deep  tissues,  but  would  be  useless  and 
dangerous.  The  dose  in  II  units  is  always  after  the  rays  have  passed 
through  the  filter  and  can  u>ually  be  larger  than  the  safe  dose  of  unfil- 
tered  r-rays.  The  author's  generator  was  devised  to  produce  approx- 
imately homogeneous  .r-ravs  and  to  avoid  the  necessity  for  a  filter. 


1168 


MKIHCAL     Kl.KCTKiriTY    AND    KONTCKX    HAY 


Kxposrm:  TABI.I:  FOR  ROXTOKX-RAY  THKIIAPY 

Introiliic!i>ry.  —  l'i\v  II  or  ;m   "erythema  do<c"  i-  a  inathcinatic  quantity  of  .r- 

radiation  applied  tn  the  Mirt'ace  of  the  hody.  Thi-  quantity  of  -oh  or  medium  un- 
tiltrivd  ray-,  oinvspoiulin.i:  I'D  a  >]iark-i:ap  of  ~)  inchi'.-  or  less,  or  to  (1  Brnoist  or 
lc».  will  produce  an  rrythcina  of  tlir  skill.  If  a  filter  i-  u-ed  the  ijiiantity  which 
reache>  the  >kiu  i-  niea-ui-ed.  not  the  total  of  \\hat  is  arreMed  li\  the  filter  and  what 
p:ts>es  throimh.  Hard  ray<,  tlnmmh  a  thick  lilter.  can  lie  applied  in  much  greater 
iiuantity  than  the  "erxt'iiMiia  dose"  without  producing  an  erythema  of  the  skin  and 
with  much  invater  Item-tit  to  deep  Ic-ioiis. 

\'ery  u'l-eat  cMiitu-mn  ha>  an>en  in  reuard  to  t he  Holx.knecht  unit.  Some  oper- 
ators  measure  the  discoloration  of  the  barium  plat inoryaii id  | laMil  "at  skin  (list aiu'e," 
or  at  the  same  distance  a>  the  >k in.  One  11  mea-mvd  "al  -kin  distance"  i-  an  ery- 
t  lieina  dose  equal  to  four  11  with  t  he  past  il  at  one-half  the  di-1  ance  to  the  skm.  The 
latter  i-  ihe  original  method  and  i.-  adhered  to  in  the  present  volume. 


s 

9 

lit 


I'nless  otherwise   >tated    the   do-e-   ^iven    hel<i\v   are    "massive   doses."   not   to 
hi-  repeated  in-id''  of  four  weeks. ) 

\.    B.      'I'iii-  tahle  i-  mtendeil  fi  r  a  aenera!  uniiie;  not   as  a  prescription  to  he 

h  i\\  i-d  1  >y  a'i  inexperienceil  <  iperali  ir. 

Tin    vohauc  and  -park  and   milliamjiei'e-  ;q'e  tlii'  lie-t    iiuide.  providing  (lie  cur- 
rent    -full\   rec'i Hied.      If  there  i- inver-e  di-chariie  tl      i  HJMTCS  are  daiifierously 

mi-Ii-adiim'.      The  -tamlard   ( 'oolidjje  tuhe  and  a   rectiiied   trail-former  ai'e  excellent 
i  iplying  t  lie-e  di  »es. 


Id 

HI 


I1 1      l-'i  >r  animal  experiment- 
>timu!ate-    lymphat- 

ics         and         llicri'::-e- 

lympliocytes    in    the 

hloo'd. 


Ill 


IKi'.) 


Spark, 


7  3       10         30  10 


Id  in 


Kl'Vt  lieilia    do.-l 


10 


i5'   '10     Author'.-  do-c  l'(.r  every 
kind       n|'        therapy. 

.\l    VIT    C.MIl.-O    derilKI- 

i  it  is.  Not  to  he  re- 
peated in-idr  ot'  t'olir 
tn  >i\  weeks. 


tcriK-  iifci 
>i.\  areas. 

I  )ivi(ied  into  1 1m  e  >uc- 
cessive  da>>  l'i  •}'  each 
area. 


Always  prom  >unced  n- 
^       Iti        action. 

tn        to         Kxtivnir     (lt»P.  Deep 

12      2-1  and     indurated     cpi- 

t  hrlioina. 


'I' 


1170  MKDICAL    KLKCTKICITY    AND    KOXTC.EN    HAYS 

EXPOSCKE    TAHLE    V(  >H    RONTC.EX-RA  Y    THERAPY 


X  '. 

'•'!• 

."> 

7i) 

:r>(  i 

10 

3 

si 

'.»'. 

."> 

VI) 

100 

10 

'1 

9 

in 

10 

0 

[) 

10 

-• 

10 

0 

9 

in 

6 

10 

0 

9 

in 

i9j 

.  .  3 

<i 

10 

(3) 

3.  Pte. 

'.» 

10 

(9) 

3 

«.i 

10 

.33. 

10 

3 

'j 

11) 

37 

10 

4 

') 

ID 

30 

111 

1,  ctr. 

3,   etc 


2")      "id      KilN    r-arcoma   cells    in 
vivo. 

.'•50     (ill      Kills  carcinoma  cells  in 

VIVO. 


1        '_'       Twice  a  week. 
'2        1        '  )nce  a  week. 

I  )ee|)  or  indurated  epi- 

t  heiioma. 

Faint  erythema  in  a 
month  and  pro- 
nounced in  six  or 
eight  weeks. 


Twice  a  week;  well- 
marked  erythema  in 
a  month. 

Deeper  epithelioma. 

Krvthema  dose. 


Hi 


lor  ^  or 

10 


10     21 


Prostate;  each  of  sev- 
eral perineal.  coccy- 
geal,  and  suprapubic 
parts  once  or  twice  a 
month. 

l\  H.  three  times  a 
week  with  thick  sec- 
ondary filter. 

Exophthalmic  goiter. 

Mediastinal  glands  10  x 
on  each  of  ten  areas 
in  a  couple  of  day-;. 

Tinea  capit is. 
Lupus. 

( 'ancer  of  brea~t .  Each 
of  about  six  areas. 

Thymus.  Thick  leather. 
Front;  and  in  worst 
ca.-es  front  and  back. 

Animal  experiment  30 
to  (.IO  ma.  min.  =  7 
to  21  H.-f  glass  filter; 

IK,  effect  on  tubercle 
bacilli  or  S/iijifii/ln- 
firciix  a  H''i  >!.•<  except 
to  render  tliem  more 
Hl-cep»ible  to  being 

killed  bv  :;c,'  r. 


KOXTCKXOTHK11APY 


1171 


Spark, 
niches. 

Benoist 
Bauer. 

Ma. 

Min. 

• 

Ma. 

min- 
UteK. 

I  >].--         Kilter  nun.  of     1  1  Ji  =  2  \  ' 
tain-e,      aluminum  un- 
indies.         le.ss  stated. 

II  1    X 

It) 

(IS)       2 

(l()j     |       IS 

.")  and  1  rum. 

-10     SO      F.  Winter.1 

brass 

1'terine  fibroma  each  of 

two      ti-inch      areas; 

lower  abdomen,   two 

of  back. 

Protect      1-inch      strip 

median  line. 

These  four  applications 

in  two  days  at  end  of 

menstruation.   Cause 

amenorrhea  at  once. 

Measure  SO  x  by  ion- 

tophoresis. One  of  his 

cases  had  dermatitis. 

(A'o/r. — Other  filters  for  applying  very  hard  .r-rays  are  .'  mm.  copper  <,r  10  nun. 
aluminum  in  lean  patients;  or  1  mm.  copper  ordinarily.) 

(.\  i>t< •.— Most  of  the  above  .r-ray  dosage  is  quoted  from  other  writers.  The 
author's  own  dose  is  0-inch  spark.  ^  ma.,  five  minutes  at  10  inches  distance.) 

(Xatc. — The  6-inch  spark  in  the  author's  dose  for  radiotherapy  is  measured  be- 
tween moderately  sharp  points.  If  measured  bet  ween  polished  walls  J  inch  in  diam- 
eter the  spark  would  be  4-2  inches.; 


1.  STALKS  OK  HAHDNKSS  OK  .r- 


Benoist  (Bauer  same  values). 

Wehnelt.                                                        Walter. 

Degrees  B. 

Degrees  Wh.                                                     Degrees  W. 

(About) 

2 

l.S  to  2 

2  to  3 

3 

O 

4  to  o 

4 

6| 

o  to  0 

5 

7| 

0 

6 

8 

0  to  7 

7 

9 

? 

s 

10  to  11 

7  to  S 

Knits  H.                     Tints.                       Knits. 

Tints. 

Knits  \. 

Kaloms. 

1    II 

2  X 

l.l  H 

3  X 

1  kalom 

:{  H 

4  II 

5  II-               Tint  B                    4 
0  H 

7  to  v  I! 

'int  0 
'int  0  to  I 
'int   I 
'int   I  to  11 
'int   II 

ti  X 
s  X 
10  X 
12  X 
14-10  X 

2  kaloms 
o.j  kaloms 

11  II 

int   III 

2s  X 

20  to  22  II 

'int    IV 

40-44  X 

'Arch.  dT.lec.  Med.,  July.  U'T 
I'^rvtht  ma  dose. 


1172  MEDICAL    KLKi  TKK  1TY    AM)    ROXTdKX    KAYS 

^T-RAY   TREATMENT   IN  PARTICULAR   DISEASES 
SKIN  DISEASES 

The  .r-ray  produce.--  atrophy  of  the  more  highly  specialized  elements 
of  the  r-kin.  Thi-  is  utili/nl -in  the  treatment  of  acne,  sycosis,  hyper- 
trichoMs.  and  excessive  sweating'. 

Acne.-  Schamberg1  regards  tlie  .r-ray  as  the  mo.-1  important  single 
therapeutic  measure  in  acne,  hut  says  that  other  measures  are  to  be 
coinhined  with  it.  (^specially  expression  ot  the  comedones  or  black- 
heads. The  latter  is  a  measure  which  the  present  author  regards  as 
undesirable  on  account  of  scarring;  freeing  the  sebaceous  glands  by 
Irictioii  with  tar  soap  and  warm  water  seem  to  me  preferable. 

The  applications  may  be  of  the  frequently  repeated  mild  type  or  of  a 
more  severe  type,  such  as  2  Holzknecht  units  repeated  every  couple  of 
weeks.  In  eh  her  case  it  is  necessary  to  produce  a  slight  reddening 
of  the  sui'face,  and  the  anticathode  should  be  10  inches  or  more  from  the 
face,  so  that  the  effect  may  be  about  equal  on  the  whole  surface  exposed. 
The  vacuum  should  be  the  lowest  that  will  produce  a  brilliant  radiance 
in  the  lluoroscope  (resistance  about  1  inch,  radiometer  about  2).  The 
eyes.  hair,  and  eyebrows  should  be  protected,  a  localizing  shield  being 
very  convenient.  Treatment  by  the  .r-ray  alone  will  effect  a  cure  in 
the  majority  of  these  cases  in  from  three  to  six  months.  Combined 
with  hiirh-frequency  currents  as  a  stimulating  application  the  time  is 
somewhat  shortened  and  the  assurance  of  success  is  greater.  My 
own  treatment  is  the  .r-ray  and  high-frequency  currents  combined  with 
the  following  medicinal  means:  Internally. 

ir,-.  ij : 

....  ...    :JT.    I  : 

LT.  v : 

ur.  v: 

;ul.    ,~  ij.  —  M. 


1  his  is  m  \-  t  reat  mem    fur  all  forms  ot    acne,  and  the  wor.-l   cases  even  of 

a<-:;<-   ro-acca  have  been   completely  and   permanently  cured.      ( )nlv  the 

•    ./'-ray  treatment   i-  required  in  this  combination,  and  this  is  an 

e-pec;al  advantage,  because  more  severe   applications  of   the  .r-ray  mav 

lie  -kin.     The  latter  condition  resembles  t  he  shrivelling 

1  ••     ii  a  Lie.      1  consider  it  uiiuecessarv  t  o  sqiiee/e  out  comedones 

mde-irable  to  incise  or  curet   the  pustules.      The  scarring  that 

•''    .   liy  that   -ort  of  treatment   i-  sunplv  terrible. 

Hypertrichosis.      Mild  repeated  applications  of  the  ./--ray,  scarcely 

•     than    to   uraduallv  Ian   the  skin,   are  entirelv   ineffective  in 

i1!'!)!.      To   succeed    it    i-    nece.-sarv    to   produce  a 

the  -km  accompanied  bv  lo.-s  of  liair.     'I'his  must 

be    repeuti    ,    alter   about    three    months    and    perhaps    more   than    once 

after  that,      'i  '  '"ollicles  can  certainly  be  destroyed,  but   whether 

V       ^'i.rk  Mc.lical  .JciuriiHl.  Fch.  _':;.   I'jiiT. 


ROXTOEXOTIIERAPY  1173 

this  can  be  done  without  producing  sonic  degree  of  atrophv  of  the  skin 
is  questionable.  With  careful  management,  this  atrophy  mav  he  -o 
slight  as  to  he  a  very  great  improvement  over  the  original  condition  in 

cases  with  almost  a  heard,  hut  in  cases  with  just  a  slight  exaggeration  of 
the  normal  downy  growth  ,r-rav  treatment  is  not  to  be  recommended. 
Tor  .r-ray  treatment  the  vacuum  should  be  low,  the  neighboring  parts 
of  the  face  protected,  and  the  application  may  consist  of  .'!  II.  repeated 
once  every  six  or  eight  weeks  during  six  to  twenty  months;  or  of  '1  II. 
every  three  or  four  weeks  for  six  months,  then  stopping  for  two  months 
to  see  whether  the  atrophy  is  uoiiiLi'  to  be  so  marked  as  to  make  further 
treatment  undesirable.  If  this  is  not  1  lie  case  treat  ment  is  recommended. 

Another  plan  is  to  give  a  course  of  from  six  to  ten  treatments  of  such  a 
nature  as  to  produce  a  reaction  from  their  total  effect,  and  still  have 
each  treatment  so  mild  and  the  intervals  between  them  so  long  that 
when  the  reaction  begins  the  treatments  may  be  stopped  with  a  knowl- 
edge that  the  effect  will  not  go  to  an  undesirable  extent.  This  reaction 
should  be  accompanied  by  complete  loss  of  hair  over  the  exposed  area, 
and  after  it  has  subsided  the  skin  should  be  left  as  smooth  as  a  baby's. 
The  hair  almost  all  returns  after  two  or  three  months  and  the  course  of 
treatment  has  to  be  applied  again.  Three  or  four  courses  of  treatment 
may  be  required  during  the  course  of  a  year,  and  are  likely  to  be  partly 
successful  in  permanently  lessening  the  amount  of  hair.  This  method 
is  attended  by  the  usual  risk  of  causing  slight  atrophy  of  the  skin,  and 
too  severe  a  reaction  must  be  guarded  against  tor  two  reasons — one 
because  it  is  painful  and  temporarily  disfiguring,  and  another  because  it 
mav  give  occasion  for  some  legal  claim  against  the  operator.  The  pa- 
tient ought  to  be  told  that  the  treatment  necessarily  involves  the  pro- 
duction of  an  inflammatory  reaction,  or  ".c-ray  burn,'  accompanied 
by  .-on  ie  redness,  pain,  and  swelling,  that  it  is  not  certain  that  all  t  he 
hail'  will  be  permanently  removed,  and  that  there  is  some  possibility 
of  the  skin  being  left  somewhat  thin  and  puckered  afterward.  It 
seems  to  be  a  matter  which  lh"  operator  should  approach  with  a  feeling 
that  there  is  probablv  very  little  credit  to  be  gained  from  treating  such 
a  case  and  that  the  wrong  kind  ot  a  patient  may  make  trouble  tor  him. 
It  may  be  undertaken  at  the  earnest  solicitation  of  a  patient  who  is 
disfigured  by  a  regular  beard,  and  who  understands  that  the  iv-ult  may 
no;  be  complete  destruction  of  all  the  hairs  and  that  there  may  be  some 
effect  upi m  t he  skin. 

A  patient  lias  recently  been  seen  by  the  author  who  was  treated  eight 
yea!'-  ago  in  another  city.  There  had  never  been  any  redness  or  pain 
or  swelling.  The  hair  had  -imply  fallen  out,  but  had  returned,  and  six 
month.-  later  atrophy  and  shriveling  of  the  .-kin  -et  in.  This  has  re- 
cently become  less  and  les-  apparent  .  but  t  he  chin  .-till  look-  a  lit  t  le  as  if 
it  had  been  the  seat  of  a  very  mild  but  thickly  di.-tributed  small-pox 
erupi  ion. 

f  A  i'i>! icdt /mi  _/'<//•    II  UJH  I'ti'icfmmx.-    The   following  records 
f  treatments  given  by  the  author,  and  which  produced  the 
reaction  accompanied  by  the  temporary  falling  out  of  all 
region  treated:  110-voli  direct  current;  12-inch  induction- 
t   interrupter:  primary  current    1  amperes:  Kriedlander 
i/e  and  stle  as  the  M  Tiller  No.  1 '.].  onl     t  he  anticat  hode  was 


1174  MEDICAL    ELECTRICITY    AND    ROXTGEX    RAYS 

ance  equivalent  to  that  of  a  4-inch  spark.  There  was  1  ma.  of  secondary 
current  passing  through  the  x-ray  tube.  No  series  spark-gap  was  used. 
Distance  from  anticathode  to  surface  of  the  skin  7  inches;  12  ohms'  resist- 
ance in  rheostat.  Applications  were  made  every  other  (lay—  three  were  of 
one  minute  each,  one  of  two  minutes  each,  three  of  three  minutes  each, 
two  of  five  minutes,  and  one  of  three  minutes.  The  total  exposure 
amounted  to  7  Holzknecht  units,  applied  in  three  weeks.  The  first  effect 
was  less  rapid  growth  of  the  hair  and  some  tanning  and  freckling  and  some 
tenderness.  This  was  noted  two  weeks  from  the  first  application  and 
after  about  -  Holxknecht  units  had  been  applied.  Four  days  later 
tin1  hairs  were  brittle.  After  the  full  three  weeks'  applications  of  a  total 
of  7  Holzknecht  units  there  was  commencing  redness  of  the  >kin.  The 
desired  dose  having  been  applied  the  applications  were  stopped  and  the 
further  progress  of  the  reaction  was  noted.  The  portion  of  the  face 
which  had  been  treated  became  quite  a  fiery  red  and  somewhat  swollen 
and  quite  painful.  This  gradually  changed  TO  a  darker  red  or  almost 
a  brown  color.  There  was  desquamation  of  the  epidermis  and  com- 
plete falling  out  of  the  hair,  but  without  any  ulceration.  The  face  had 
to  be  treated  in  several  different  sections,  each  part  in  succession  receiv- 
ing the  amount  of  exposure  specified  above,  while  the  rest  of  the  face 
was  protected  by  sheet  lead.  Besides  the  atrophy  of  the  skin,  there 
may  develop  a  dilatation  of  the  superficial  blood-vessels,  such  as  seen 
upon  the  noses  of  chronic  alcoholic  subjects.  X-ray  treatment,  then,  is 
indicated  only  in  seven1  cases  where  the  resulting  slight  changes  in  the 
skin  amount  to  nothing  in  comparison  to  the  relief  experienced  from 
tin-  removal  of  the  original  disfigurement.  The  more  experienced  the 
operator,  the  better  within  certain  limits  will  he  be  able  to  regulate  the 
changes  produced  in  the  skin. 

The  use  of  an  aluminum  filter,  1  mm.  thick,  and  the  application  of 
single  doses  of  1  Sabouraud  (o^  H.),  or  a  little  less,  is  apt  to  cause  falling 
out  of  the  hair  without  inflammatory  reaction :  it  may  have  to  lie  repeated 
several  times  to  secure  any  permanent  removal. 

Favus. — In  this  disease,  when  it-  affects  the  scalp,  the  .r-ray  is 
probablv  the  best  means  of  treatment.  The  object  should  be.  by  one 
or  t  \vo  vigorous  applications,  or  bv  a  serie.-  ot  frequently  repeated  milder 
ones,  to  produce  complete  temporary  loss  of  hair.  After  this  has  been 
produced  it  is  easy  enough  to  eliminate  the  fungus  by  suitable1  medica- 
nieiits,  but  this  is  not  the  case  if  any  hairs  have  been  left.  1  he  scalp 
,-lioul'  1  be  exposed  in  four  different  sections  i  frontal,  occipital,  temporal. 
an1!  parietal)  and  the  anticathode  should  be  tar  enough  away  (about 
](i  inches)  to  secure  uniformity  ot  action.  Sheets  ot  .r-ray  metal  torni 
the  onlv  sat  i.-t'actorv  protection  while  each  particular  portion  is  exposed. 

If  one  full  dose  is  given  it  should  be  ot'  lor.")  II.  (Holzknechl  units), 
aii'l  it  -hould  be  repealed  after  three  or  tour  weeks  over  any  portion 
v.  hi'-h  has  not  become  depilated.  '1  his  treatment  produces  a  very 
decjilnl  reaction,  which  is  most  severe  in  the  regions  already  inflamed 
by  the  disease.  The  hair  falls  out  and  there  is  considerable  desqua- 
matiori.  The  hair  begins  to  grow  again  six  weeks  after  it  has  fallen  out . 
e,  the  follicles  which  have  been  de.-t  roved  by  the  favus 
not  regenerated.  The  application  mu-1  not  be  too  severe 
llicles  will  be  destroyed  by  the  .r-ray  and  the  part  remain 
ald.  I  hi-  i-  Holxknecht 's  own  method,  but  Freund.  of 
o-i  operator-  in  America  secure  the  same  reaction  in  the 


ito.vn ;  KNOTH  KHAI>  Y  1 1 75 

course   of   three    weeks    by    repeated   milder    applications.      A    medium 
degree  of  vacuum  should  be  used. 

Alopecia  areata  is  treated  in  the  same  way  as  favus  and  with 
fairly  good  results.  The  application  need  not  extend  more  than  \  inch 
beyond  the  margin  of  the  area  affected,  and  must  be  somewhat  less 
vigorous  for  the  beard  than  for  the  scalp.  Neither  in  this  disease,  in 
favus,  not  in  any  other  is  it  likely  that  the  beneficial  effect  is  due  to 
bactericide  action.  In  favus  it  is  good  almost  solely  as  a  depilatorv. 
and  in  alopecia  areata  it  has  a  slight  stimulating  effect  upon  the  hair 
follicles.  This  last  is  shown  even  when  no  visible  reaction  has  been 
produced.  As  the  result  of  .r-ray  depilation  for  alopecia  areata  is  some- 
what uncertain  it  may  be  wise  to  follow  Freund's  suggestion  and  try  the 
effect  upon  one  small  area  before  treating  all  the  regions  affected. 
In  no  case  should  repeated  severe  reactions  be  used  that  would  destroy 
the  hair  follicles  entirely. 

Sycosis. — Y-ray  treatment  gives  excellent  results,  the  technic  being 
the  same  as  for  favus  of  the  face.  It  is  one  of  the  diseases  in  which  the 
.r-ray  may  be  regarded  as  a  specific. 

Psoriasis. — One  full  dose  of  '_'  II.  for  the  face  or  o.\  II.  for  the  body 
sullices  to  cause  the  disappearance  of  the  patches  over  the  area  exposed. 
The  hair  should  be  protected  by  .r-ray  metal.  No  inflammatory  reaction 
should  be  sought.  Recurrence  is  as  liable  to  take  place  as  after  any  other 
treatment.  Or  smaller  doses  may  be  given,  and  repeated  every  day  at 
first,  and  later  every  other  day.  until  the  appearance  of  the  slightest 
possible  reaction.  The  vacuum  of  the  tube  should  be  medium  or  low. 

The  author's  experience  indicates  that  the  diseased  area  is  much 
more  susceptible  to  the  .r-ray  than  the  surrounding  skin,  and  also  that  a 
second  course  of  treatment  finds  the  diseased  areas  with  an  increased 
susceptibility.  The  point  of  the  elbow  where  the  disease  is  often 
present  is  particularly  slow  to  heal  after  a  severe  dermatitis.  Smaller 
doses  than  usual  should  be  used  in  recurrent  cases  of  psoriasis. 

The  way  in  which  the  patches  disappear  is  quite  remarkable.  There 
is  no  doubt  about  this  being  due  to  the  application  of  the  x-ray,  because 
areas  which  receive  a  sufficient  dose  clean  up  completely,  while  thor-e 
insufficiently  treated  do  not  show  complete  improvement.  The  center 
of  a  large  patch  may  become  perfectly  clean  if  the  tube  is  close  to  the 
surface  and  is  kept  in  one  position,  while  the  edges  are  but  slightly 
improved.  The  distance  in  this  case  from  the  anticathode  to  the 
psoriatic  patch,  may  be  considerably  greater  than  from  the 
the  middle  of  the  patch.  As  the  intensity  diminishes 
lare  of  the  distance  the  tube  must  either  be  at  a  consider- 
o  as  to  reduce  the  difference  in  the  relative  distances,  or 
the  tube  must  be  changed  from  one 
exposure.  A  greater  distance1  requires 

If  success  requires  equal  exposure  of  all  parts  of  a  single  patch  it 
will  be  readily  seen  thai  a  number  of  patches  on  different  aspects  ot  a 
limb  must  be  treated  individually. 

The  application  >hould  lie  limited  to  the  areas  of  disease  and  a 
small  /.one  of  surrounding  skin.  This  is  not  to  prevent  undue  action 
on  the  neighboring  skin.  for.  as  already  mentioned,  the  dose  required  to 
affect  the  diseased  an -a  is  smaller  than  that  required  to  affect  the  sound 
skin.  So  many  regions  of  the  body  are  affected  that  application 
to  all  of  them  with  a  bare  x-rav  tube  miirht  produce  some  undesirable 


1170 


MKim  AL    KLKCTHU'ITY    AND    KONTCiEN    KAYS 


effects — baldness,  sterility,  e>r  constitutional  disturbance.  Such  a  shield 
as  the1  Kipperger  is  use-fill.  It  is  a  box  made  e>f  opaque  material  com- 
pletely surrounding  the1  .r-ray  tube  except  for  a  4-inch  opening;.  This 
opening  is  directed  toward  the1  part  to  be  treated.  Smaller  diaphragms 
may  be  used,  or  a  piece1  e>f  shevt  leael  may  be1  fastene*d  to  the  surface  of 
the  body  with  an  ope'iiing  e>f  the1  right  size  anil  shape  to  expose  the 
pse>riatic  pate-h  to  the'  action  of  the  .r-ray. 

Lipoma.-  This  disease*,  especially  Dercum's  disease,  has  been  treated 
by  the  applications  of  .r-rays  Xe>.  5  to  Xo.  7  Be-noist.  Xogier,1  who 
reports  sue-h  a  case1,  founel  that  the  fatty  tumor  would  diminish  in  size 
but  not  entirely  elisappear.  The  pain  of  lipomatosa  dolorosa  is  quickly 
relieveel  by  the'  same  treatment.  The  disease  take's  a  long  course  of 
.r-ray  tre'atment,  and  there  does  not  seem  to  be-  any  great  probability  of 
cure-.  Massive  e loses  of  4  or  5  II.,  repeated  every  two  or  three1  weeks, 
ha\v  been  use-el  in  the-  e-ases  thus  far  re-porte-d. 

Keloid.-  The*  successful  treatment  of  the  disease  by  the  .r-ray  has 
bei'ii  reported  by  many  different  operators,  and  it  can  no  longer  be  con- 
sidered xub  JHflice.  Some  degree  of  re- 
action  should  be  exe-ited,  but  no  ulcer- 
ation.  Kays  Xo.  •">  and  a  quantity  of 
about  (')  H.  may  be  applied  once  in  five 
of  six  weeks,  or  milder  doses,  amounting 
to  the  same  total,  in  about  three*  weeks, 
and  t he-n  followed  by  an  intermission 
of  three1  weeks. 

The*  case1  shown  in  Fig.  813  of  keloid 
of  the  lobe' of  the  ear  was  given  a  num- 
ber of  .r-ray  applications  at  St.  Barthol- 
omew's ('Unie-  with  commencing  bene- 
fit, but  abandoned  treatment  be-fe>re  it 
wascomple-te-.  It  was  more  of  a  tumor 
than  most  e-ases  of  keloid.  They  are 
often  more1  like  hypertrophied  se-ar-tis- 
sue-  and  are  then  more*  quie-kly  amenable 
to  treatment.  It  take's  from  three  to 
six  months  in  any  ca.-e,  and  t  he-re  are* 
so  far  no  <  >bservat  ions  to  show  whether 
it  removes  the  tendency  to  the  develop- 
ment of  thi-  abnormal  tissue  in  new 


It  i- 


a  t  rea tment  which  is  to  be 
extent,  where  electrolysis 
-  in  it  t  he  only  successful 
ic-1  one.  Treatment  bv 


'/'•'  ',,.^'1,/n/i  in  in  '/if  Trait nn  nl  of  Ktlnid.      Thi-  me1  hod  of  treatment 

:  bv  the  author  in   l^'.M.'  and  consist-  in  the-  internal  ad- 

•    (.  liypndcnuie  ii-'1  '  'f  the  druu  in  question.      Thiosina- 

inin  ;  |)roduces  a  very  marked  ten  UK  irary  leukocytosis 

;ilid  n  i-iii'v  to  cause  the  absorption  of  fibrous  or  ricat  ricial  tis- 

,iir.      [•  n   kdoid,  in  which  it   noi  only  causes  the  absorption 

,  remove's  the  constitutional  tendency  to  it. 

\I,-,).  IV..P,  iin-1  i  Tin..  I-.  :Ji v.">.  M.-iy  l>."i,  I1.)!)."). 

M.   lir:,!  .Ir.unial.   \^\. 


RONTGENOTHERAPY  1177 

The  importance  of  the  latter  feature  is  very  great.  These  rases 
develop  a  larger  keloid  in  the  scar  if  the  original  growth  is  excised. 
Thev  develop  one  in  each  needle-puncture  if  hypodermic  1  real  inent 
is  adopted.  A  keloid  developed  in  the  scar  from  too  intense  photo- 
therapy in  a  case  reported  by  Helot. 

A  case  treated  by  the  author  was  one  of  a  college  student  who  de- 
veloped keloid  in  a  vaccination  scar.  After  one  excision  this  formed 
a  large  mass  with  numerous  prolongations,  disfiguring  and  greatly 
disabling  the  arm.  Thiosinamin  was  at  first  used  by  hypodermic 
injection  near  the  growth,  but  as  new  keloids  soon  developed  in  each 
needle  puncture  the  method  ol  administration  by  capsules  to  be 
swallowed  was  adopted.  Treatment  had  to  be  continued  for  about  a 
year,  but  resulted  in  a  complete  cure  of  the  growth  and  of  the  tendency 
to  the  formation  of  others. 

\\hether  the  .r-ray  alone  will  cure  the  tendency  to  keloid  is  a  question 
rot  yet  settled. 

Cases  of  multiple  keloid  have  been  reported  by  Sievers'  which  were 
cured  by  the  x-ray  without  any  other  medication  and  had  shown  no 
recurrence  in  two  years. 

l\adium  is  used  very  successfully  for  keloid  by  the  author  and  others. 

Hyperidrosis.—  This  disease  has  been  treated  by  the  .r-ray  and  a 
successful  technic  described  by  Leopold  Freund.'-' 

My  own  technic  is  illustrated  in  the  following  cases  of  UK  st  extni- 
ordinary  hyperidrosis  palmaris.  The  patient,  a  phy-ician  twenty- 
seven  years  old.  had  always  suffered  from  such  sweating  of  the  palmar 
surface  of  the  hand  and  fingers  that  sixty  seconds  after  wiping  his  hands 
on  a  towel  the  unnatural  secretion  would  fall  from  his  finger-tips  in  great 
drops. 

The  treatment  consisted  in  a  single  massive  do»e  of  each  hand  of 
unfiltered  .r-rays  about  Xo.  7  Henoist  penetration  and  Fi\,  Tousey  inten- 
r-iiy  and  about  10  Ilol/knecht  units  of  quantity.  Thi-  dose  was  applied 
from  a  tungsten  anticathode  7-inch  bulb  excited  by  a  1'J-inch  induction- 
coil  with  a  wheel  mechanical  interrupter.  The  primary  current  was 
.")  to  I)  amperes,  the  ^econdary  1  to  ]\  ma.:  the  distance  from  the  anti- 
cathode  to  the  -kin  It1,  inches  and  the  time  of  exposure  twenty-right 
minute-.  This  was  more  than  a  Saboliraud  and  Noire  ery.thema  dose 
of  -V,  11.,  and  was  made  possible  by  the  toughness  of  the  >kin  in- 
vnlved  and  preliminary  tests  of  it-  sensitivenes.-  in  this  particular  ca-e. 

The  result  was  redness  and  -welling  coming  on  after  a  period  of  incu- 
bation. I  Vy  desquamation,  except  in  one  -mall  area  where  there  was  an 
actual  blister.  The  -kin  was  left  -niooth  ar.d  dry.  and  when  seen  a  few 
month-  later  the  palmar  surfaces  were  as  dry  a-  a  bone. 

Thi-  radiance  required  an  expo-ui'e  of  -ixiy  n  mute-  upon  a  Sabou- 
raild barium  platinocvanid  pastil  at  o'1,  inches  from  the  anticathode 
to  change  it  to  Tint  IV  Sixtv  minute-  at  !•>  inches  twice  a-  far  as  the 
p:  -til  would,  t  here  fore,  have  applii  d  a  Sabouraud  do-e  to  the  -kin  and 
on< -quarter  thai  lime  or  fifteen  minutes  would  have  been  a  Sabouraud 
do-e  at  (I1,  inches,  the  di-tance  at  which  the  application  was  actually 
made  to  the  skin. 

./•-I  'ay  applications  ab-olutely  and  permanently  -topped  this  disease. 
but  were  followed  by  kcratosis  and  fissures  requiring  treatment  bv 


il<X  MKDICAI.    ELECTRICITY    AND    RONTIJEN    HAYS 

radium.  The  .r-ray  applications  had  boon  made  tentatively,  not  by  a 
sinirle  massive  dose.  It  is  hard  to  say  whether  smaller  dose's  would 
have  cured  the  hyperidrosis  without  injury,  but  I  feel  sure  that  in  this 
case  the  patient  would  have  preferred  the  disease  to  the  after-effect 
of  the  treat  ment . 

Eczema.  This  disease  is  very  amenable  to  .r-ray  treatment,  and, 
according  to  Leonard,  the  lowest  practicable  degree  of  penetration  pro- 
duces the  best  roults.  The  .r-ray  tube  may  show  the  blue  cathode 
stream  and  the  radiometer  may  indicate  a  penetration  of  only  Xo.  1 
Benoist.  Practically  the  whole  radiation  is  arrested  by  the  skin — 
absorbed  by  it.  A  tube  in  this  condition  converts  a  very  small  fraction 
of  the  electric  power  passing  through  it  into  Rontgen  radiance1.  The 
latter  is  not  very  penverful,  and  rather  long  exposure's  are  required,  and 
the  tube1  may  be  very  near  the  skin.  It  is  difficult  to  define  the  dosage 
exactlv.  and  probably  the  safest  way.  until  one1  has  experience  as  a 
guide,  is  to  give  practically  the  same1  expeisure-s  that  would  be  given  at 
the  same  distance  with  a  medium  degree  of  vacuum.  Other  operators 
use  a  medium  vacuum.  Xo  screen  for  soft  rays  is  used.  If  a  single  dose 
instead  of  divided  doses  is  given  it  should  amount  to  3  or  4  II.;  the  limbs 
will  require  separate  expe>sures. 

Warts  and  Moles. — These  may  be  treated  by  frequent  exposure  to 
mode-rate  doses  or  a  single1  exposure  te)  a  very  heavy  dose  (X  LI.).  In  the 
latter  case1  it  is  very  important  to  prefect  the'  semnd  skin.  Some  ot 
these  show  a  tendency  te)  de-velop  into  epithelioma,  and  in  such  cases  it 
seems  probable  that  the1  slower  milder  tre-atment  is  better.  There  is 
,-ome  reason  to  belie-ve  that  a  severe  change  in  the1  skin  from  the1  .r-ray 
produces  m  some  cases  a  tendency  toward  malignancy. 

Piaelium  is  the  author's  preference  and  high-frequency  sparks  his 
ne\t  choice  for  these  cases. 

Pruritus.  Itching  of  the-  skin,  with  or  without  anatomic  change1, 
i-  relieved  by  mild  applications  of  the  x-ray  combined  with  the  use  of 
high-frequency  currents  from  ultraviolet  ray  vacuum  electrodes  or  from 
•opper  electrodes.  This,  however,  should  be  combined  with  other 
appropriate  treatment,  such  as  an  ointment  containing  resore-in.  car- 
bolic ;icid.  alum,  and  ichthyol:  the  internal  use  of  salophen,  10  gr.  three' 
time-  a  day.  The  latter  is  of  the  greatest  service1  in  the  cases  which 
are  dependent  upon  a  uric-acid  diathe.-is. 

Nevi.  Va.-e-ular  or  hairy  nevi  or  port -wine  stains  may  be  treated  by 
the  ./'-ray,  but  mild  application-  produce  little  or  no  effect.  There 
nr>  1-1  be  a  very  marked  reaction,  although  it  is  better  to  avoid  ulceration. 
After  successful  treatment  the  skin  may  show  slight  atrophy  and  its 
may  not  be  absolutely  normal,  having  somewhat  of  a  cicatricial 
In  the-se  cases  the  choice  of  treatment  lies  bet  ween  radium, 
e,  electrolysis,  exci-ion.  and  the  ./--ray.  Where  the  nevus  is 
at  it  is  possible  to  -ecure'  a  linear  cicatrix  exe-ision  is  best. 
-i-  i-  excelle-nt  for  nevi  of  moderate  -i/e  where  the'  cosmetic 
\'-i-ion  would  be  bad.  The  .r-ray  i-  adapted  to  case's  of  large- 
•1  in  which  the  disfigurement  i-  so  great  that  the  result  ob- 
.•••n  though  it  can  hardly  be  expecte-d  to  be  perfect,  will  be  a 
'  improvement .  In  the-e  cases  a  .-ingle-  elose  of  }  H.  may  be 
\i  the  neighboring  part-,  and  repeating  it  after  a  month. 
id  do-e-  mav  be  the  -am<-  or  of  -lightly  greater  strength,  de- 
ipon  the  degree-  of  reaction.  The  vacuum  should  be  medium, 


KONT<  i  KXOTI 1 K  K  A  P  Y 


1179 


and  if  repeated  fractional  doses  are  given  the  radiance  should  he  rather 
hrilliant,  so  as  to  he  a  little  more  than  tin'  standard  dose  on  p.  1  !(>(>. 
The  decree  of  reaction  sought  is  one  accompanied  hy  slight  blistering, 
hut  without  ulcerat ion. 

Chronic  Ulcers.  The  .r-ray  does  not  appear  to  have  any  specific 
effect  upon  an  ulcer,  hut  exposure  to  the  r-ray  may  produce  two  different 
results.  There  may  be  a  stimulation  due  to  the  charge  of  static  elec- 
tricity emanating  from  the  .r-ray  tube  and  having  a  tendency  to  stimu- 
late healing,  and  then'  is  a  regular  cloud  of  atmospheric  dust  repelled 
from  the  .r-ray  tube,  and  if  a  raw  surface  is  exposed  to  this  a  dangerous 
implantation  of  bacteria  and  other  particles  may  take  place.  This  last 
effect  may  be  prevented  by  the  interposition  of  a  thin  piece  of  cloth. 
Mild  doses,  like  those  on  p.  1  !(>(>,  repeated  only  once  a  week,  may  be 
used.  There  are  so  mtftiy  better  applications,  electric  and  otherwise, 
that  the  x-ray  will  hardly  be  chosen  unless  there  is  some  special  reason, 
such  as  the  fear  of  a  development  of  malignancy. 

Syphilitic  Gumma. — A  ease  of  ulceration  of  the  side  of  the  neck  from 
a  broken-down  syphilitic  gumma,  which  had  remained  open  for  a  couple 
of  years,  was  successfully  treated  by  means  of  high-frequency  effiuves 
and  very  soft  .r-rays.1 

Syphilitic  Rhinoscleroma. — A  case  referred  to  the  author  as  prob- 
ably one  of  lupus,  but  which  was  subsequently  thought  to  be  of  a  syph- 
ilitic nature,  did  remarkably  we'll  under  .r-ray  applications,  and  was 
promptly  and  completely  cured  when  antisyphilitic  medication  was 
added  (Fig.  814). 

Scorbo,  of  Naples,  has  treated  a  syphilitic  lesion  of  the  skin  by 
ultraviolet  light  and  the  .r-ray. 

Rhinoscleroma. — FreumF  reports  the  cure  of  such  a  case  by  twenty- 
five  applications  of  the  x-ray.  The  nose  was  thick  and  indurated  and 
the  nostrils  were  blocked  up  with 
nodules,  which  also  involved  the 
hard  palate  and  the  posterior  wall 
of  the  pharynx.  Ditt  rich's  bacilli 
had  been  found  in  the  tissues. 

Leukoplakia  Buccalis. — Lednr' 
reports  :•>  cases  treated  by  ex- 
posure of  the  tongue  to  medium 
soft  rays  at  a  distance  of  20  cm. 
^  inches)  from  t  he  ant  icat  hode  for 
two  minutes  at  the  first  treatment, 
possibly  repeated  in  three  weeks. 
The  letikoplakia  completely  and 
permanently  disappeared  without 
the  sound  part  of  the  tongue  show- 
in  sj;  any  effect  from  t  he  apphcat  ion. 

Cicatricial  Contractions. — These  yield  slowly  to  the  influence  of 
mild  applications  of  the  .r-ray.  Thiosinamin  is  also  excellent  in  these 
cases,  and  requires  to  he  given  internally  for  six  months  or  more.  Its 
effect  is  more  fully  explained  in  the  paragraph  on  keloid. 

1  Laquerriere,  Bulletin  officiel  <Ir  la  Soru'to  Kranrai-e  d'Electrotherapie,   Dec., 


I  Hi)." 


-  Wiener  Me.l    Wocli.,  June  L'.l.  1  <><):>.  p.  127 
'  Arch.  (I'Klectric'ite  Medicale,  Feb.  10.  190 


11X0  MKDICAL   Ki.KeTKK  Try  AND  HONTOKN  HAYS 

Effects  of  War  Injuries.1  -  Fibrous  tissue  forming  about  nerves  after 
war  injuries  is  absorbed  by  .r-rays.  10  or  12  II.  under  a  filter,  once  a 
month  with  cross-fire,  without  injury  to  the  nerve  and  with  restoration 
of  function.  Also  adherent  cicatrix.  painful  cicatrix.  keloid.  neuritis, 
ankvlo-i-.  Heaujard1-'  finds  benefit  from  the  .r-ray  in  crippling  or  painful 
wounds,  neuroma,  cau-alsiia.  and  cicatricial  compression  of  a  nerve. 
Laquerrieiv  advises  it  in  infiltration  and  inflammation  of  tendon 
sheaths,  and  old  hydrarthrosis.  It  is  most  effective  in  the  case  of  young 
cicatricial  tissue. 

Leprosy.  Thi-  is  a  disease  in  which  some  of  the  cutaneous  lesions 
are  susceptible  of  improvement  by  r-ray  treatment,  and,  according  to 
Ouilin.  th"  .r-ray  -eems  to  have  a  specific  effect  upon  the  morbid  tissue 
wit  hour  affect  in»  t  he  neighborin.ir  sound  tissues.  The  application  should 
be  -uflicient  to  produce  a  mild  erythema,  not  *ulceration :  5  or  (i  Holx- 
knecht  unit-  should  be  applied  to  each  of  the  regions  treated.  This 
amount  may  be  a  single  dose  or  divided  amonu;  several  sessions. 

Scholtx.  on  the  other  hand,  did  not  observe  any  decided  benefit, 
clinically  or  microscopically,  from  .r-ray  applications  in  2  cases  of 
leprosy  which  lie  treated. 

From  a  study  of  cases  of  leprosy  made  in  the  hospitals  of  Norway  it 
seems  TO  the  author  that  the  r-ray  may  be  of  service*  in  the  treatment  of 
the  tubercular  cutaneems  and  subcutaneous  nodules  and  of  the  chronic 
ulcers  which  characterixe  the  disease.  The*  larire-r  question,  as  to 
whether  the  disease  itself  can  be  cured  by  .r-ray  applications  ove-r  the 
spine  or  the  hematopoietic  organs,  must  lie  left  undecided,  but  when  one 
sees  case  after  case  which  has  suffered  from  the  steady  advance*  of  this 
terribly  mutilating  disease  for  fifty  years  it  seems  as  if  an  effort  should 
be  made*  to  conquer  the1  bacillary  infection  or  the  trophoneurosis  by 
.r-ray  treatment.  Applied  in  these  two  directions,  and  with  courses 
of  treatment  extending  over  long  periods  of  time,  but  only  to  the  extent 
of  causing  stimulation  of  the  .skin,  never  ulceration,  it  may  prove  the 
means  of  curing  the  disease.  We  know  of  nothing  else  in  the  whole 
Pharmacopeia  which  has  so  marked  an  effect  upon  the  whole  organism 
in  therapeutic  de>ses. 

.1  (.''!.-•'  nf  Leprosy  Apparently  Cured  Inj  the  x-Ray. — This  case  is  re- 
ported  by  Victor  G.  Hciser  of  the  Leper  Hospital  at  Manila."  The 
different  le.-ions  wore  exposed  for  ten  minutes  every  third  day  to  a 
ie-e  ju.-l  intense  enough  to  show  the  out  line  of  the-  in tra carpal  bones 
An  ordinary  .r-ray  tube  was  used  with  an  1^-ine-h  induct ion- 
d  a  mercurv  turbine  interrupter.  The  distance'  from  the  tube  was 
IPS.  for  tl  e  fir.-l  three  we-e-ks,  beginning  Nov.  .">,  I'.tOti.  but  improve- 
•cte-d  u mil  after  the  distance*  had  bee^n  reduced  to  0  or  7 
June.  l'.!O7.  after  .-even  month.-'  treatment,  the  lesions 
red.  Miid  the  lepra  bacilli,  which  had  be-en  abundant, 
Jo  demon-irate.  l'-v  Januarv.  I'.'Hs,  after  fourteen 


no    ane'si  hot  i< 

!, 


Ji  HP  and   -buy,    I'.iOs,   it   wa 
:        bodv.       At    the  1: 


: ;  l .  I ' 


RONTGENOTHERAPY  1 181 

190S,  after  nearly  two  years'  treatment,  the  patient  was  apparently 
cured. 

Scleroderma. — Encouraging  results  have  been  reported  from  ap- 
plications of  6  or  S  llolxknccht  units  of  Xo.  5  rays  made  every  three 
weeks.  The  sclerotic  patches  are  apparently  less  sensitive  to  the  x-ray 
than  normal  skin;  for  these  rather  large  doses  do  not  excite  an  inflam- 
matory reaction.  Xo  complete  cures  have  been  reported. 

Chilblains. — The  redness  and  pain  are  relieved  even  in  severe 
recurrent  cases  by  the  .r-ray  and  high-frequency  currents.  Ichthyol 
ointment  is  excellent  and  so  is  white  lead.  The  author  has  had  very 
great  success  in  treating  these  cases  by  immersing  the  feet  in  mackerel 
brine,  as  hot  as  it  can  be  borne,  for  about  fifteen  minutes.  This  may  be 
repeated  in  two  or  three  days,  and  these  two  applications  will  probably 
suffice  for  the  whole  winter  and  there  may  never  be  a  recurrence. 

Tinea  Capitis  or  Ringworm  of  the  Scalp. — The  discovery  that  the 
.r-ray  is  the  most  effective  means  of  treating  this  disease  is  due  largely 
to  Sabouraud  and  Xoire,  and  their  names  have  become  associated  also 
with  a  convenient  method  of  measuring  the  dosage  of  .r-ray  required 
for  the  treatment  of  this  disease.  Their  method  is  to  apply  rays  of  & 
medium  or  low  degree  of  vacuum  (Xo.  4  or  5  Benoist),  with  a  sufficient 
exposure  to  produce  complete  falling  of  the  hair  without  inflammatory 
reaction,  and  without  ulceration.  Their  method  of  measurement  is 
based  upon  the  change  in  color  undergone  by  barium  platinocyanid 
when  exposed  to  the  .r-ray.  A  little  tablet  coated  with  this  chemical, 
which  is  the  same  that  is  used  in  fluoroscopes,  is  placed  S  cm.  from  the 
anticathode,  while  the  surface  to  be  treated  is  at  a  distance  of  15  cm. 
\\  hen  it  has  turned  to  a  standard  color,  so  as  to  exactly  match  one  of 
the  brownish-yellow  tablets  supplied  with  the  apparatus,  we  know  that 
a  certain  quantity  of  .r-ray  has  been  applied.  One  of  the  test  tablets 
indicates  an  exposure  which  is  about  1  he  proper  dose  for  ringworm.  This 
indicates  the  application  of  •">.',  11..  which  is  the  large.- 1  dose  that  can  be 
applied  without  producing  radiodermatitis.  The  quantity  to  be  applied 
varies  a  little.  Only  4  11.  is  required  for  a  child,  and  o  11.  is  the  average 
dose  for  application  to  the  hairy  scalp  in  adult.-.  The  Sabouraud  and 
Xoire  pastils  form  a  most  convenient  means  of  measuring  the  dose. 
Haivt's  little  device  holds  the  pastil  attached  to  the  .r-ray  tube  at  just 
the  correct  distance  from  the  antieathode.  Ordinary  light  affects  the 
barium  platinocyanid,  so  the  pa.-Hl  is  kept  covered  by  black  paper, 
except  occasionally,  when  it  is  tinned  back  for  comparison  with  the  test 
object ,  which  also  is  held  in  position.  It  is  not  necessary  to  turn  off  1  he 
current  while  making  this  comparison.  Holzknecht  's  chromonu hornet er. 
depending  on  the  change  in  color  of  another  cheinic  compound,  may 
be  used.  The  author's  own  method  is  based  upon  the  intensity  of  the 
./'-rat  ha  nee.  which  can  be  measured  before  tin-  exposure  is  begun,  enabling 
one  to  determine  beforehand  just  how  many  minutes  the  .''-ray  is  to  be 
applied.  It  is  described  on  a  not  her  pa  ire  and  is  excellent  for  many  pur- 
poses, but  presents  too  great  a  personal  equation  for  general  use  in  these 
part icular  cases. 

The  treatment  of  these  cases  without  any  exact  means  of  measuring 
the  amount  of  .r-ray  applied  is  to  be  most  strongly  deprecated.  Before 
the  introduction  of  the  Sabouraud  and  Xoire  method  of  app'vinir  an 
exactly  measured  dose  at  once  or  in  two  parts,  separated  by  a  day  or 
two,  the  best  radiologist  had  most  uncertain  results  in  these  cases. 


MKDICAL    KLECTHH'ITY    AND    KOXTGEN    KAYS 


An  example  of  the  best  technic  would  be  (i-inch  spark,  70  kv.,  400 
ma.  seconds  at  10  inches  distance  for  the  total  application  over  any 
one  area.  At  a  distance  of  1">  cm.  from  the  anticathode  to  the  skin  in 
one  of  the  author's  exposures  with  another  technic  twenty  minutes 
amounted  to  about  4  llol/knecht  units,  and  was  suitable  for  the  total 
dose,  not  to  be  repeated,  in  a  case  of  tinea  capitis  in  a  child  three  years 
old  (Fig.  SI")).  The  treatment  was  successful. 

All  portions  of  the  scalp 
that  are  affected  must  be 
treated,  and  all  must  receive 
an  equal  application  of  the  x- 
ray.  The  strength  of  the  rays 
and  hence  the  quantity  ab- 
sorbed in  a  given  time  varies 
inversely  as  the  square  of  the 
distance  from  the  anticath- 
ode. The  convex  shape  of 
the  head  would  result  in  the 
part  directed  toward  the  .r-ray 
tube  being  very  much  more 
affected  than  the  other  parts  if 
a  single  exposure  were  made 
in  a  fixed  position.  It  is  nec- 
essary to  turn  first  one  part 
and  then  another  toward  the 
tube,  protecting  other  parts 
by  sheet -lead  while  one  part  is 
I  icing  t  reatecl.  Practically  t  he 
whole  scalp  may  be  treated 
in  four  sections— frontal,  oc- 
cipital, and  right  and  left 
parietal. 

It  is  unwise  to  attempt  to  make  this  subdivision  of  the  exposure 
by  means  of  a  diaphragm  which  regulates  the  distribution  of  the  rays 
from  the  tube.  Such  an  arrangement  is  excellent  for  treating  a  single 
area,  but  it  would  be  very  difficult  to  prevent  some  contiguous  portions 
ot  two  neighboring  areas  from  receiving  a  double  exposure,  and  other 
parts  would  perhaps  not  receive  any.  I'sing  the  sheet-lead,  a  portion 
on  one  side  of  a  perfectly  straight  line  may  be  treated  during  the  first 
part  of  the  exposure  and  the  portion  on  the  other  side  of  that  line  during 
the  second  part  of  the  exposure. 

Kach  successive  part  that  is  exposed  is  to  receive  an  exposure  of 
about  I  I  lol/kneclit  unit s. 

/  Action  <>f  UK  :f-l{(\\i  nt  Tinm  ('u/nfi*.-  -The  disease  appears 
to  an  infection  by  microorganisms  which  are  limited  to  the 
')•  of  epidermis  in  the  hair  follicles.  In  this  position  the  in- 
difficiilt  or  impossible  to  eradicate  by  any  ordinary  chemic 
ic;d  means.  The  hairs  break  off  if  one  tries  to  pull  them  out, 


Mo. —  HiiiKwcirin  of  the  scalp  (tino.-i   capitis) 
cured  I  v  .r-rav. 


R<  )  XT(  !  EX  OTH  E  R  A  P  Y  1183 

The  now  hair  grows  out  free  from  infection. 

The  sound  hairs  of  the  area  exposed  to  the  x-my  fall  out  just  the 
same  as  the  diseased  ones  and  are  also  replaced  by  new  hairs. 

The  I)<in</er  of  Reinfection,  —  The  disease  is  a  most,  contagious  one, 
and  one  portion  of  the  scalp  may  be  inoculated  from  any  other  part. 
The  exfoliated  hairs  carry  perfectly  live  and  active  germs  (tricophyti), 
and  must_be  prevented  from  starting  new  areas  of  disease.  Saboufaud 
makes  daily  applications  of  flowers  of  sulphur  to  the  diseased  area  from 
the  tenth  to  the  thirtieth  day  after  irradiation. 

Such  an  application  as 

H.     Sulphur  preeip.  \ 

Sp.  vini  reel.      /  '  •    ^ 

,A(J"ai  .......................................  ad. 

big.  —  Shake  before  usin 


is  also  effective.     Or  the  scalp  may  be  rubbed  daily  with 

U.     Tr.  iocli  ..........................................    oiss; 

Sp.  vini  reel  if  ...................................  ad.   3j.—  M. 

Sig.  -Lotion. 

Ringworm  of  Other  Regions  than  the  Scalp.  —  The  same  disease  affect- 
ing the  beard  should  receive  milder  applications  of  the  x-ray  because  of 
the  greater  susceptibility  of  the  face  to  the  x-ray  dermatitis.  It  will 
probably  be  found  unwise  to  make  an  application  severe  enough  to 
produce  complete  depilation  on  any  part  of  the  face. 

Mycosis  Fungoides.  —  The  x-ray  treatment  yields  good  results  in  this 
condition.  The  application  should  be  thorough,  3  to  5  11.  at  a  single 
application,  protecting  the  surrounding  parts,  or  repeated  applications 
of  a  strength  that  the  operator  knows  will  gradually  produce  a  decided 
reaction. 

Lupus.  —  The  x-ray  treatment  of  lupus  is  practically  certain  of  con- 
siderable success.  The  time  required  for  each  treatment  is  only  a  few 
minutes  and  the  number  of  treatments  is  from  five  to  fifty.  In  both 
these  particulars  it  possesses  advantages  over  the  Finsen  treatment. 
Some  cases  treated  by  the  best  and  most  expensive  Finsen  apparatus 
require  four  hundred  and  seventy  treatments.  Whether  there  is  an 
equal  prospect  of  success  with  the  two  methods  has  not  been  definitely 
settled,  but  in  most  cases  the  preference  lies  with  the  x-ray,  at  least  for  a 
fair  trial,  or  as  a  preparation  for  Finsen  treatment.  A  great  many 
cases  have  been  reported,  and  many  have  been  cured.  Though  perhaps 
the  majority  cannot  be  entirely  cured  by  the  x-ray  alone.  The  method 
produces  a  better  cosmetic  effect  than  curetage  or  cauterization  and  is 
free  from  pain,  but  it  requires  about  as  long  a  course  of  treatment  as  any 
other  met  hod. 

The  t  real  ment  by  mild  applications,  repeated  every  two  or  three  days 
until  a  slight  reaction  has  been  produced,  and  bv  then  maintaining  this 
degree  of  reaction  throughout,  is  the  one  which  is  perhaps  the  safest. 
For  details  of  the  met  hod  sin1  page  1  1  o4.  The  ot  her  method  involves  the 
application  of  3  to  ~)  II.  once  a  month  for  five  or  ten  months  and  is  also 
good.  In  lupus  vulgaris  the  change  produced  by  the  x-ray  is  one  of 
degeneration  of  the  lupus  nodules  followed  by  inflammatory  changes  in 
the  neighoring  tissue,  and  if  severe  applications  are  made  the  whole 
diseased  area  may  slough  out  ;  Tors  Ilolxknecht  units  at  a  single  session, 


1184 


MKDH'AL    KLKCTKH'ITY    AND    RONTGEN    HAYS 


H. 


or  as  the  total  of  the  applications  made  in  a  single  week,  will  produce 
slouii-hinu-.  but  this  is  seldom  desirable.  The  ulcer  is  painful  and  takes 
perhaps  many  months  to  heal.  Milder  applications  without  an  intense 
reaction  produce  a  sort  of  sclerosis,  followed  by  absorption  of  the  lupoid 
tissue  with  disappearance  of  the  bacilli. 

It  is  important  to  note  that  the  effect  upon  the  disease  is  not  due  to 
the  bactericide  action  of  the  .r-ray.  The  latter  is  so  weak  lhat_  it  would 
require  tremendous  overdoses  to  directly  influence  the  bacilli.  I  he 
effect  is  produced  directly  upon  the  tissue-cells,  and  they  are  in  some 
way  enabled  to  dispose  of  the  bacilli. 

Whether  strong  or  weak  applications  are  made,  the  .r-ray  certainly 
has  a  curative  effect,  and  the  milder  treatment  carefully  conducted  is 
less  apt  to  cause  a  painful  ulceration  at  any  sta<re  of  the  case.  ()i  course, 
fresh  lupus  nodules  may  come  to  the  surface  and  prolong  the  treat- 
ment. 

In  lupus  erythematosus  there  is  not  the  same  reason  to  expect  ulcera- 
tion. and  so  either  the  gradual  method  or  that  by  massive  do-es  of  3  or  1 
repeated  every  month  or  six  weeks,  may  be  employed.     '1  he  vacuum 

in  the  tube  used  for  the  milder 
frequent  applications  in  all 
form-  of  lupus  should  be  me- 
dium, o  or  4  inches  spark  re- 
sistance and  •">  to  7  radiometer. 
but  for  the  heavier  doses  the 
vacuum  should  be  low.  1  or  2 
inches  spark  resistance  and  2 
or  :>  radiometer.  It  will  often 
be  found  advantageous  to  com- 
1  line  occasional  curetaiie  of  cer- 
tain nodules  with  the  .r-ray 
treatment.  After  the  disease 
<:enn  appears  to  have  been 

.  it  will  often  happen  that  a  complete  cure  will  be  promoted 
by  Fin.-en  treatment,  and  will  not  take  place  under  the  .r-ray  alone  even 
if  ci  iiit  inued  for  a  lonir  t  ime. 

Helot'  analyzes  the  treatment  of  different  forms  of  lupus  as  follows: 
"  \\  hi le  certain  cases  of  lupus  of  the  ext  remit ies  are  benefited  bv  curet  - 
au'e.  any  extensive  case  of  lupus,  whether  ulcerated  or  not,  ouirht  to  be 
'  .  •••:.•'•;  b;.  the  j'-ray  :  t  his  t  real  me  in  i.-  more  rapid  ami  effective.  Kebei- 
lio  .-  points  are  to  be  treated  by  phototherapy,  bin  it  may  be  that  the 
produces  changes  in  the  tissues  which  interfere  with  the  beneficial 
action  of  the  arc  Imht.  Phototherapy  properly  applied  Lnves  excellent 
mall  locali/ed  lllpUS." 

•  authors  to  \\hom  our  knowledge  of  the  curative  effect 
i  pus  i.-  due  a  re  Jut  assy,  Sch  iff.  I-  reund.  Scholt  z.  Campbell, 
nerv.     Ormsby,     Kummel.     (iocht,    Albers     Schonberi:. 
-ser.    Lee,     I'lahler,     I    hlmaiili.     I'usey,     Kienbock,    Holx- 
\\illiam-.  and  P>elot. 

thi-  disease  was  referred   to  the  author  by  Dr.  Jar- 
ie    was    -ixtv-seven    vears   old,  and    had    had   a    patch   of   lupus 
the   check    for  about    a   year.      Her  father  had  a  similar 

he  nose  to  ulcerate  awav. 


MI 


A 


RONTGENOTHERAPY  1  IS") 

Tlic  technic  for  ouch  treatment  was  as  follows:  No.  K)  Miiller  1ul»e, 
radiometer  No.  2.1  Henoist  ;  resistance  2.1  inches;  S-inch  induct  ion- 
coil;  Caldwell  interrupter;  Jl()-volt  direct  current;  1  amperes  primarv 
current;  1  ma.  secondary  cunvnt;  ant  icathode  and  accessory  anode 
connected;  distance,  S  inches;  intensity,  No.  5  Tousey ;  S  ohm.-'  resistance 
in  rheostat.  Five-minute  exposure  equaled  1  Holzknecht  unit.  The 
exposures  were  of  two  minutes'  duration  and  thirty-five  treatments 
were  given  in  a  period  of  two  and  a  half  months.  The  total  exposure 
during  this  time  amounted  to  about  I  I  Ilol/knecht  units.  There  was 
at  no  time  anything  more  than  the  slightest  decree  of  redness  and  itch- 
iu.il.'.  A  complete  cure  was  effected  and  there  has  been  no  recurrence 
in  three  years.  There  is  no  scar  upon  t  he  face.  It  should  be  added  that 
the  diagnosis  was  made  from  the  clinical  appearance  and  history,  not 
from  microscopic  examination.  It  is,  therefore,  not  absolutely  certain 
that  the  disease  was  lupus  and  not  epithelioma. 

Absence  of  Effect  Upon  Hydatid  Cysts.—  There  is  no  apparent 
reason  why  the  .r-ray  should  succeed  in  destroying  the  parasites  which 
cause  this  disease,  and  Deve  has  found  from  experiments  on  this  disease 
in  rabbits  that  this  supposition  is  correct. 

Rontgenotherapy  for  1'yorrhca  Alvcolarix  is  described  on  page  tilt;. 

X-RAY  THERAPY   IN  TUBERCULOSIS 

Experiments  by  Bergonie  and  Tissier1  showed  that  the  x-ray  had 
no  effect  upon  the  tubercle  bacilli  in  a  culture,  and  that  it  had  no  marked 
effect  upon  the  lesions  of  experimental  tuberculosis.  They  concluded 
that  the  x-ray  had  a  doubtful  influence  upon  clinical  surgical  tubercu- 
losis and  none  upon  phthisis. 

Miihsam,  at  the  same  date,'-'  found  that  the  .r-ray  did  not  produce 
tuberculosis  in  guinea-pigs,  and  that  it  only  slightly  attenuated  the'  local 
manifestations  of  this  disease  if  the  animal  was  inoculated  with  it.  The 
x-ray  did  not  completely  cure  tuberculosis  in  guinea-pigs. 

Rodet  and  Bertin-Sans,  about  the  same  time,:i  found  that  the  x-ray 
had  an  unfavorable  effect  upon  nutrition,  and  that  in  cases  of  tubercu- 
losis the  x-ray  moderated  the  infection  in  the  lymphatic  glands,  but 
somewhat  favored  generalization  in  the  viscera.  Their  verdict  was 
that  no  benefit  resulted  from  the  treatment. 

Hieder,  a  little  later,1  came  to  the  conclusion  from  his  observations 
that,  while  the  x-ray  appeared  to  attenuate  or  kill  different  di>ease  germs 
in  glass  test-tubes,  the  rays  had  no  such  effect  upon  infectious  processes 
in  animals  inoculated  with  different  pathogenic  germs.  His  results  at 
that  time  seemed  to  show  that  local  tubercular  processes  were  favorably 
influenced,  and  that  in  some  cases  generalization  of  the  disease  was 
antagonized.  The  animals  experimented  upon  died,  however,  doubtless 
from  organic  disorders  produced  by  the  irradiation.  lie  reported  neg- 
ative re.-ults  in  human  tuberculosis. 

Since  that  time  increased  knowledge  as  to  the  dosage  of  the  x-ray 
has  led  to  improved  re.-ults.  and  the  x-ray  has  become  a  most  valuable 
therapeutic  au'ent.  especially  for  localized  tubercular  lesion-.  Bergonie* 

1  Congress  of  Tuberculosis,  7ti.  P;iri.-.  1>',)S. 
-  Munch.  Mc«l.  \V,»ch..  _'t.  715,  Nov.  in.  IV.K. 

3  Arch.  .I'Klcctnntc  Mc.lirale,    H:;.  iv.tv 

4  Munch.  Me<l.  W.M-h.,  ,)unr  lx  iv.t'.t. 

5  C.  K.  A  cad.  dcs  Science-,   MO.  >s',l,  Paris,  March  27.  11)0.1. 


finds  I  hat.  with  modern  technic.  the  .r-ray  has  a  clearly  favorable  effect 
upon  iion-suppurat  ive  tubercular  glands.  According  to  tin-  observer 

all  the  tunietieil  glands  which  are  treate<l  become  smaller,  but  rarely 
completely  disappear.  The  disease,  as  it  affects  the  joints,  the  larynx, 
i  he  peritoneum,  the  lungs,  the  skin,  and  other  parts,  has  been  very 
favorably  influenced  by  the  .r-ray.  We  know  thai  tuberculosis,  like 
manv  other  infectious  diseases,  is  often  recovered  from  if  the  local  lesion 
i-  i 'tin!  rolled  and  if  1  he  general  dealt  h  is  maintained,  and  1  he  local  lesions 
are  often  of  a  character  or  situation  to  make  them  difficult  to  directly 
influence  bv  anv  other  measures  than  the  .r-ray. 

The  effect  ot  the  .''-ray  is  not  directly  upon  the  tubercle  bacilli,  but 
upon  tin-  lowly  orga ni/.fd  tissue  with  rapidly  developing  cells  charac- 
tt-ri-tic  of  this  di.-ease.  The  •••ffect  of  the  ./'-ray  i.-  greatly  added  to  by 
combining  with  it  the  use  of  high-frequency  current-.  The  latter  may 
be  applied  from  ultraviolet  ray  vacuum  electrodes,  or  bv  placing  the 
pat  ient  bet  ween  t  \vo  ( )udin  or  Guilleminot  resonators  in  such  a  way  that 
the  eifluve  or  perha])s  only  the  invisible  di.-char^e  is  intercepted  by  the 
pat  id  it 's  body.  1  he  ozonizing  effect  of  high-frequency  currents,  a])  plied 
in  either  of  these  ways,  is  of  great  therapeutic  value,  acting  by  stimulat- 
ing 'hi-  tis-ue  cells  and  increasing  metabolism  as  well  as  by  circulatory 
stimulation. 

Kempster'  states:  "Rontgen  rays  are  not  gennicidal,  but  inhibit 
reproduction  of  germ-  and  stimulate  the  tissues,  causing  phagocytosis, 
wh'n-h  will  destroy  an  unproductive  colony  of  bacteria."  (Quoted  from 
.lour.  Amer.  Electrotherapy  and  Radiology.) 

According  to  .).  1).  (libson-  the  x-ray  heals  tuberculosis  of  the  lungs 
by  ab-.orbing,  softening,  and  eliminating  fibroid  ti-.-ue. 

Rontgen  Therapy  in  Cutaneous  Tuberculosis.  Moderate  exposures 
repeated  t  wo  or  three  times  a  week  have  a  curative  effect  upon  the 
warty  or  nodular  type  of  the  disease  and  upon  the  ulcers  and  fistula; 
which  accompany  another  type.  A  suitable  exposure  for  each  applica- 
tion i-  one  and  a  half  minutes,  at  a  distance  of  10  inches  from  the  anti- 
cathode,  with  a  resistance  of  4  inches,  55  kv.,  and  '•>  ma.  Kadi  applica- 
tion amount-  to  about  \  Holzknecht  unit,  and  the  application  may  be 
kept  up  for-  three  or  four  weeks  if  necessary  and  then  intermit  fed. 

Tubercular  Adenitis.     Chronic  tubercular  gland-  with  periadenitis, 

treated    by    Hoiit'_!.en    rav.    may   become   -mailer   and    change   to   fibrous 

nodule-  which  do  not  entirely  di-appear.      Acute  tubercular  glands,  and 

tho-e  aheadv  havmg-a   tendency  to  soften,  may  be  caused  to  undergo 

chee-\    degeneration.      The  author  has  observed  excellent    results  from 

.•'-:  •:"   treatment    m   -uppurative  tubercular  glands  oj   the  neck  already 

opened   spontaneously  or  by  the  surgeon'.-  knife.      He  has  successfully 

ca-e  of  chronic  -inu-  of  the  liack   following  an  operation  for 

ilar  o-teitis  or  tubercular  arthritis  of  the  -pine-by  exposure  to  the 

The  ,/--ra  v.-  were  of  a  qualit  v  of  a  bout  No.  .">  ]  lenoi-t .      The  ant  i- 

iboul    IK  indie-  from  the  -urface  o|   the  t>odv,  and  the  ap- 

For  about  five  minute-  every  other  day  until  the  skin  be- 

1  ••ddein-d.      Kadi  application  amounted  to  about    1    Hol/- 

I  !<  .'it  'jenot  hera  pv   re-ull-   in    better   cicatrices   as  well   as 

in  ca-e-  of  tuberculous  abscess  and  -mil-. 

Tubercular    Lymphatic    Glands    of    the    Neck.     These    are    readily 


KONTCKXOTHKKAI'Y 


US? 


amenable  to  treatment   by  a  radiance  of  a  penetration  of  No.   ">  or  (> 

Benoist.  Short  applications  of  about  a  minute  and  a  half,  at  a  distance 
of  about  10  inches  from  the  ant icathode,  may  be  made  three  times  a 
week  until  some  reaction  appears.  Then  the  treatment  should  be  inter- 
mitted. Kach  application,  made  according  to  this  plan,  should  he 
calculated  to  be  a  little  less  than  1  Hol/knecht  unit.  Another  plan  is  to 
make  massive  applications  of  1  or  .">  II.  at  a  single  session,  or  as  1  he  total 
of  two  or  more  sessions,  occurriim'  within  the  course  of  two  or  three  davs. 


\o  more  application-  should  be  made  tor  two  or  three  week-,  but  it  mav 
then  be  repeated.  It  i<  quite  important  to  limit  the  application  by  a 
shield  or  by  c<>vennu'  all  other  pa  Us  ot  the  patient  with  -heet  lead. 
Haldne--  and  sterility  and  any  possible  toxemia  ai'e  thi-  avoided. 

The  re-tilt-  are  that   the  glandular  mass   shrivels  and  certain  uland- 
cease   to   be   palpable,   while  others   remain   as   innocuous   -mall   tihrn'i- 
iiodule-.      Leonai'd    found    that    the    lymphatic    vessels    are    convertei 
into  iilii'ou-  cords.      ( 'a-e-  treated  hv  the  author  make  thi-  treatini 


11SS  MEDICAL    KLECTKICITV    AND    H(")NT(iEN    RAYS 

tubercular  glands  of  the  neck  seem  preferable  to  surgical  extirpation, 
because  this  treatment  leave>  no  scar  and  because  it  permanently  closes 
certain  lymphatic  channels  and  hence  tends  to  protect  the  patient  from 
general  infection. 

Tuberculosis  of  the  Mediastinal  Lymphatic  Glands.-  Disease  in 
this  location  is  also  amenable  to  treatment  and  the  radiance  required 
is  one  which  will  give  a  good  fluoroseopic  image  of  the  chest,  or  will 
produce  a  good  radiograph  of  the  chest  with  an  exposure  of  five  min- 
utes or  less,  ."i-inch  resistance.  ()•")  kv.,  and  '.')  ma.  The  anticathode 
should  be  ]'.)  inches  from  the  surface  of  the  body,  and  an  exposure  of 
three  minutes  may  be  given  twice  a  week,  with  intermissions  on  the 
development  of  some  redness  of  the  skin.  A  screen  for  soft  rays,  made 
by  interposing  a  piece  of  sole  leather,  or  a  single  layer  of  tin-foil,  or  a 
sheet  of  aluminum  ft\T  inch  thick  between  the  .r-ray  tube  and  the  surface 
of  the  body,  will  tend  to  prevent  dermatitis  while  permitting  the  pas- 
sage of  the  more  penetrating  rays,  which  alone  could  reach  the  seat  of 
disease  anyway  and  which  are  less  irritating  to  the  skin.  The  nearest 
skin  surface  should  receive  about  2  Holzknecht  units  a  week,  and  a 
distance  of  13  inches  is  great  enough  not  to  make  too  great  a  dispro- 
portion between  the  distance  to  the  skin  and  that  to  the  seat  of  disease. 
If  the  tube  were  so  near  that  the  distance  from  the  anticathode  to  the 
cutaneous  surface  were  only  half  the  distance  to  the  deep-seated 
le-ion.  the  divergence  of  the  rays  would  result  in  the  skin  being  ex- 
posed to  a  radiance  four  times  as  intense  as  that  which  reached  the 
mediastinal  glands.  Under  such  conditions  it  would  be  difficult  to 
produce  any  therapeutic  effect  upon  the  mediastinal  glands  without 
a  bad  effect  upon  the  skin. 

Massive  doses  are  available  here  as  elsewhere,  but  probably  are  less 
desirable  than  mild  frequently  repeated  ones. 

The  results  of  this  treatment  are  variable,  but  it  is  certainly  capable 
of  great  benefit  in  certain  cases. 

Associated  as  this  disease  is  so  apt  to  be  with  pulmonary  tubercu- 
losis, it  will  often  be  advantageous  to  combine  the  .r-ray  and  high- 
frequency  currents  in  its  treatment. 

Hypertrophy  of  the  thymus  gland  causing  compression  and  cyanosis 
or  even  suffocation  has  been  successfully  treated  by  Regaud  and  ( 'remien. 
They  sometimes  apply  Hi  II.  units  to  the  skin  measured  after  having 
pa--ed  through  4  mm.  aluminum.  A  milder  application  is  made  twenty 
days  later.  Wei  11  uses  the  same  filtration,  but  a  smaller  dose  of  ^  to  7  II. 
For  example,  anticathode  b")  cm.  or  0  inche-.  and  filter  7\  cm.,  or  '.'> 
inche-  from  the  skin  and  the  application  made  from  both  front  and  back 
( if  t  lie  upper  part  of  t  he  1  horax. 

Tubercular  Lymphatic  Glands  in  Other  Regions.-  These  are  treated 
in  t  he  same  way  and  wit  h  due  regard  to  t  heir  superficial  or  deep  situation. 
The  applications  should  be  localized. 

Rene  I)e-p]als  ha-  made  blood  examination-  in  patient-  with  tuber- 
cular adenitis  treated  by  the  x-ray  and  find-  a  reaction  similar  to  that 
which  occurs  111  leukemia  under  this  treatment.' 

Tubercular  Peritonitis.      Kdntgen   ray  treatment    ha-  proved  bene- 
ficial  iii  ;i   ca-e  of  tubercular  peritonitis  in   which  an  exploratory  lapa- 
rotomy  had  been  done  and  the  fluid  evacuated  and  the  diagnosis  (•(in- 
firmed  l,y  the  micro-cope.      Repeated  tapping  was  required  until  .7--ray 
1  I.--  Radium,  Sept.  i:,.  P.m.V  p.  :',OO. 


RONTGENOTHERAPY  1 189 

applications  were  made.      A   lasting  cure  was  obtained  in  this  way,  a 
slight  recurrence  disappearing  at  once  under  .r-ray  treatment. 

The  application  in  such  cases  should  be  over  the  whole  front  of  the 
abdomen,  of  a  spark  resistance  of  (i  inches.  !•>  ma.,  sixty  seconds  without 
a  filter  or,  preferably,  one  hundred  and  twenty  seconds  through  o  mm. 
of  aluminum,  the  anticathode  being  at  a  distance  of  10  inches  from  the 
skin.  This  amount  of  radiation  is  applied  three  times  a  week.  The 
soft  rays  which  might  cause  dermatitis  are  arrested  by  the  aluminum 
screen. 

Tuberculosis  of  the  Kidney.  -This  is  a  disease  in  which  the  .r-ray 
and  high-frequency  currents  did  good  in  one  of  the  author's  cases.  The 
./•-ray  seemed  to  act  by  breaking  down  exudative  masses  and  the  high- 
frequency  currents  seemed  to  stimulate  the  elimination  of  enormous 
collections  of  pus.  The  local  condition  was  improved,  but  general 
infection  had  probably  already  taken  place  and  the  patient  died.  The 
applications  should  be  limited  to  the  lumbar  region  on  the  affected  side. 
The  anticathode  should  be  10  inches  from  the  surface  of  the  body  and 
the  radiance  should  have  a  penetration  of  Xo.  (>  Benoist  and  the  same 
exposure  a-  tor  tuberculous  peritonitis.  A  screen  for  soft  rays  will 
protect  the  skin  to  a  certain  extent.  The  exposures  should  be  given  two 
or  three  times  a  week,  and  be  of  <uch  a  length  that  redness  will  develop 
in  three  weeks  and  change  to  bronzing  in  six  weeks,  without  ever  having 
any  sorene-s.  An  application  amounting  to  1  II.  at  the  surface  of  the 
body  twice  a  week  is  about  correct. 

Massive  doses  ot  i  or  .">  II.,  applied  once  everv  four  or  five  weeks,  are 
permissible,  but  are  probably  somewhat  less  desirable.  A  mild  con- 
tinuous effect  seems  usually  better  for  tubercular  processes,  and  this  is 
a  region  where1  the  toxennc  effect,  which  sometimes  immediately  fol- 
lows any  .r-radiat  ion.  might  be  serious  if  the  dose  were  a  large  one. 

The  x-Ray  Treatment  of  Pulmonary  Tuberculosis.-  A  certain 
number  of  patients  have  recovered  from  tuberculosis  of  the  lungs  utidei 
treatment  by  the  .r-ray  and  high-frequency  currents  and  others  under 
high-frequency  currents  alone.  These  recoveries  have  been  character- 
ized by  the  disappearance  of  ail  the  symptoms  of  the  disease,  including 
the  bacilli  in  the  sputum,  and  by  the  radiographic  findings  character- 
istic of  cured  pulmonary  tuberculosis. 

Other  cases  have  shown  considerable  improvement  under  .r-ray 
treatment  alone,  and  these  cases  have  been  mostly  those  in  which  the 
applications  have  been  severe  enough  to  excite  a  cutaneous  reaction 
with  a  possible  count  erirrit  ant  effect. 

The  best  opinion  at  the  present  time  seems  to  be  that  the  .r-ray  has 
little  i!  anv  permanently  curative  effect  m  pulmonary  tuberculosis. 

If  ii  is  used  either  alone  or  in  combination  with  high-frequency 
currents  the  technic  is  the  same  as  for  tubercular  media -thud  glands,  and 
milt  1  frequent Iv  repeated  doses  are  lo  be  given  with  the  production  of  a 
slight  react  ion  upon  i  he  skin. 

Tuberculosis  of  Bones  and  Joints.—  This  localized  form  of  disease 
is  certainly  benefited  by  the  r-ray  and  some  cases  are  cured.  A  chronic 
sinu-  oi  the  back  from  ;m  old  operated  tubercular  osteitis  of  the  lower 
dorsal  vertebra1  in  one  of  the  auil  or's  cases  healed  after  a  few  applica- 
tion- of  the  ./'-ray  and  of  hi:Ji-frei|uei;cy  currents  from  ultraviolet  ray 
vacuum  elect  1'ot  le-.  I'ltbercula  r  rheumal  ism  oi  the  Wl'ist  has  been  cured 
by  ./--ray  applications,  and  the  ;;;iii.  edema,  and  stiffness  removed 


1190  MKDICAL    Kl.Ki  TKK1TY    AND    HoNTCKN     HAYS 

i  reported  l>y  Rehoul',  and  Beclere  ha-  reported  a  case  of  spina  ventosa, 
tubercular  osteitis  of  a  finger  \viili  fistula1,  entirely  cured  by  the  .r-ray. 

It  is  to  1  ic  recou iinei H let  1  at  t  he  different  stages  of  hone  or  joint  1  uber- 
culosis.  when  an  operation  does  not  seem  to  lie  indicated  or  when  it  lias 
not  proved  completely  successful  and  repetition  oi  the  operation  seems 
undesirahle. 

The  .r-ray  should  generally  he  applied  from  several  different  direc- 
tion^, exposing  only  a  small  area  of  skin  at  a  time,  so  as  to  secure  an 
effect  upon  the  deep  tissue  without  much  on  the  skin.  The  choice  lies 
between  mild,  frequently  repeated  applications,  continued  until  there 
i-  slight  cutaneous  reaction,  and  massive  doses,  applied  at  one  or  two 
se-<ion<.  The  penetration  should  he  Xo.  (i  Benoist  and  the  resistance 
i)  inches  70  kv.,  '•'•>  ma.,  at  a  distance  of  10  inches  from  the  anticathode, 
for  t  lie  wri-t .  hip.  or  spine. 

The  mild  frequent  applications  would  require  an  exposure  of  one 
minut"  two  oc  three  times  a  week,  and  the  massive  doses  would  require 
five  minute-'  exposure  at  a  single  session,  or  as  the  total  exposure,  during 
the  coin1-"  of  two  or  three  days.  The  author's  preference  is  for  frequent 
mild  application-.  Xo  severe  reaction  is  to  he  sought,  and  the  use  of  a 
screen  for  soft  rays  may  he  found  desirahle.  With  o  mm.  of  aluminum 
the  expo-ure  should  he  twice  as  long. 

lioedercr.1  who  has  collected  the  published  reports  upon  the  treat- 
ment of  tubercular  joints  and  other  local  tubercular  lesions,  finds  no 
evidence  that  .r-ray  treatment  tends  to  a  general  dissemination  of  the 
disease.  Mv  own  experience  agrees  with  this  conclusion. 

Spina  ventosa  is  very  favorably  influenced,  while  the  .r-ray  does  not 
seem  to  accomplish  much  in  Pott's  disease  or  tuberculosis  of  the  hip. 

ARTHRITIS  DEFORMANS 

Anders,  Daland,  and  Pfahler  report  excellent  results  from  the 
application  of  the  ./--ray  in  arthritis  deformans.  This  treatment  should 
be  combined  with  other  measures  appropriate  to  the  individual  cases. 

The  Author's  Experience  with  the  ./'-Ray  in  a  Variety  of  Rheu- 
matic Affections. — The  .r-ray  applications  have  a  decided  alterative  ef- 
fect in  this  whole  cla-<  of  cases  and  are  a  valuable  adjunct  to  treatment 
by  hijrh-frequency  currents.  The  latter  are  applied  by  vacuum  elec- 
trode-. A  c;i-e  without  bony  changes  discoverable  in  the  radiograph 
.  .  ly  yield-  re.-idily  to  the  combined  treatment.  l»ony  changes, 
however,  do  not  appear  to  he  cured,  though  the  urea  test  benefit  may  be 
'i  in  'lie  wav  of  arresting  the  progress  of  the  disease.  Illustrative 
(•a-e-  ;tre  tn'-iit  n  >nei  1  on  p.  .V. ID. 

In   the  phy-iot  herapy   of   war   injurie-  chronic   ei't'u-ion-  into  joints 

ii     it*-d  by  /-ray  applications  every  two  week-  'Hirt/:;). 

TRACHOMA 

•'il1-  o|    r-rav   therapv   in   tin-  di-ea-e  have  not    been  exactly 
•     'hi     hand-   of  different    operator-.      Ya--ioiit  insky'1   reports 
.  '  I'-li    the  .r-rav   certamlv   had   a    inafkeil   influence   upon   the 
•  •-.    e-pecj.-dlv    the    infiltration.     The    pannu-    yielded 


RONTGENOTHERAPY  1  101 

slowly.  lie  (lid  not  secure  anv  complete  cures,  no  matter  how  long  or 
how  frequent  the  exposures  were.  This  tissue  seems  to  present  hut  a 
slight  tendency  to  cicat  ri/at  ion.  The  applications  were  absolutely 
painless  and  produced  no  harmful  secondary  effects  upon  the  eye. 
lie  thought  the  .r-ray  would  give  favorable  results  where  other  methods, 
have  failed. 

Xewcomet  has  had  better  success  in  entirely  curing  cases. 

A  difference  in  the  results  of  Rontgenotherapy  may  be  due  to  differ- 
ences in  technic,  and,  generally  speaking,  it  is  desirable  to  know  what 
the  results  of  treatment  with  average  apparatus  and  technic  is  likely  to 
be. 

The  exposures  must  be  calculated  with  special  reference  to  the  avoid- 
ance of  injury  to  th<>  eve.  In  some  cases  little  metal  or  enamel  shields 
(Fig.  807,  p.  1140)  may  be  placed  over  the  eyeball  under  the  eyelids.  A 
drop  of  cocain  solution  enables  the  eye  to  tolerate  this.  The  eye  is  then 
entirely  protected,  and  as  much  .r-radiance  may  be  applied  to  the  lids 
as  is  required.  It  is  not  necessary  to  evert  the  eyelids  in  order  to  secure 
an  effect  upon  the  mucous  surface. 

Frequently  repeated  mild  doses  art'  desirable.  The  penetration 
should  be  about  No.  4  Benoist,  the  resistance  or  equivalent  spark  4 
inch,  2  ma.,  and  the  distance  about  10  inches.  Kxposures  of  two 
minutes  three  times  a  week  amount  to  about  4  H.  in  three  weeks,  and 
this  is  about  the  proper  amount  to  apply.  The  treatment  may  be  re- 
sumed, if  necessary,  after  an  interval  of  a  couple  of  weeks. 

The  results  of  .r-ray  treatment  of  trachoma  while  very  good  are  not 
thought  to  be  quite  so  good  as  those  from  treatment  with  radium. 


RADIOTHERAPY   IN   SYRINGOMYELIA 

Successful  results  have  been  reported  by  Heaujard  and  L'llermitte,1 
Delherm,2  and  Clramequc.:!  The  applications  of  the  .r-ray  are  made  over 
the  affected  part  of  the  spine  as  indicated  by  the  location  of  the  principal 
symptoms  and  are  of  a  degree  of  penetration  equal  to  Xo.  S  Benoist  or 
7-inch  spark.  The  tube  should  be  at  a  distance  of  10  inches,  measured 
from  the  anticathode  to  the  surface  of  the  body.  Applications  of  2 
Hol/knecht  units  may  be  given  about  every  six  days  until  the  develop- 
ment of  a  cutaneous  reaction  and  then  reduced  in  strength.  It  is  too 
early,  and  there  have  been  too  few  cases  reported,  to  know  whether  the 
disease  is  permanently  curable  by  this  means.  Improvement  seems  to 
be  reasonably  certain. 

OLD   SPRAINS 

111  an  old  and  very  stout  lady  a  fall  down  stairs  resulted  in  a  sprain 
ot  the  tuetatarsophalangeal  articulation  followed  by  pain  and  dis- 
ability until  cured  by  the  .r-ray  :i  year  later.  A  localizing  shield  con- 
fined the  ra  v  to  an  area  about  1 ',  inches  in  diameter.  Six-inch  spark, 
•\  ma.  Ill-inch  distance1,  '•'>  mm.  aluminum,  ten  minutes.  1  he  patient 
noted  a  -limy  redness  of  the  -kin  and  very  marked  improvement.  A 
second  application  two  month-  later  resulted  in  a  complete  cure. 


1192  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

DISEASED  TONSILS 

The  author's  treatment  has  l>een  (i-inch  spark,  3  ma.,  13-inch  dis- 
tance. 3  mm.  aluminum,  ten  minutes.  The  application  is  external;  the 
chin  up  and  head  turned  to  the  opposite  side.  A  protective  cylinder 
3  inches  in  diameter  limits  the  rays  to  the  region  behind  the  angle  of 
the  jaw.  One  treatment  is  sufficient  for  one  tonsil,  and  where  both  are 
affected  each  side  of  the  neck  may  receive  such  an  application  at  a 
single  session  or  at  different  sessions. 

Hypertrophy  of  the  tonsils  disappears  in  a  magical  manner. 

A  case  of  quite  a  different  character  had  been  tonsillotomized  long 
before,  but  for  a  couple  of  years  had  had  constant  infection  of  the  ton- 
sillor  crypts  from  which  a  year  ago  stony  concretions  had  been  ex- 
tracted. An  application  to  both  sides  at  a  single  session  cured  the 
chronic  suppuration. 

LOCOMOTOR  ATAXIA 

The  author  has  seen  remarkable  and  lasting  benefit  from  .r-ray  and 
high-frequency  applications  to  the  region  of  the  lumbar  enlargement  of 
the  spinal  cord.  The  applications  should  be  localized,  and  mild  and 
repeated  ones  are  preferable  to  massive1  doses.  Probably  no  cases 
have  been  permanently  cured. 


.v-RAY   TREATMENT    OF    FACIAL   NEURALGIA 

The  .r-ray  examination  having  verified  the  clinical  diagnosis  of 
neuralgia  without  gross  anatomic  lesion,  the  therapeutic  applications 
mav  be  undertaken.  The  ray  should  be  of  a  penetration  of  about  Xo.  (> 
Henoi-t.  (i-inch  >park.  70  kv.,  3  ma.,  and  the  anticathode  should  be 
about  10  inches  from  the  skin.  Such  an  application  may  last  about  one 
minute,  equivalent  to  1  II.,  and  be  given  three  times  a  week.  A 
locali/inii  -hield  and  leather  screen  are  desirable;  3  mm.  aluminum 
require-  exposures  1  wice  as  long.  The  hair  and  eye-  are  to  be  protected. 
but.  generally  >peaking.  rather  a  generous  area  of  the  painful  region 
i-  to  be  expo-ed.  A  three-  to  five-minute  application  of  an  ultra- 
violet ray  uia--  vacuum  electrode  is  to  be  made  at  the  conclusion  of 
each  .r-ray  treatment. 

A  rase  of  this  kind  was  a  lady  about  sixty-five  years  of  age.  referred 

to   (he  author  by    Dr.    \V.  T.    Hull.      She  had   suffered   for  twelve  years 

from  ob-tinate  neuralgia  of  the  upper  jaw.  which  had  not  been  relieved 

series    of    siirti'ical    operations.      The    .r-ray    examination    showed 

:!  bonv  conditions.      Twelve  r-rav  and  high-frequency  treatments 

'.'  ere  Li'ivt-n  us  indicated  above,  the  ./--ray  shining  riii'lit   through  the  cheek 

. :  -.      She  had  to  leave  the  cit  V  at   the  end  of  tin-  tune  on  account  ot 

miner  heat.      The  pain  had  then  been  onlv  somewhat   relieved,  but 

i  »      Hull  reported  to  mi'  the  following  winter  that   the  pain  had  entirely 

'•a  red  during  the  summer  ami  had  ,-hown  no  sign  of  recurrence. 

1 '  •!  N  >'.\  iii'_r  i-  a  case  in  which  there  was  a  deep-seated  lesion  which 

be  readied  by  remedial  agent.-:  The  patient .  a  lady  of  about 

'.'.  a-  b  nm  trhi  in  i  he  au t  hoi-  by  Dr.  \\  .  K.  Draper,  with  a  his- 

•  ere  pain,  e.-pecially  in  the  region  of  the  right  eye  and 

•     -i    the    forehead.      A    supra-orbital    neurectomy 

H'ood  examination-  had  .-howii  a  marked  degree 

•  'I  .-.'  •      i-d  onh     partly  to  medical  treatment:  r-rav 

•  .    '  '     '  •        u   in  i  he  jaw.  ant  rum.  or  t'n  mi  a! 


RONTGENOTHERAPY 


1193 


sinus.  The  treatment  was  chiefly  by  static  electricity  and  high-fre- 
quency currents  from  ultraviolet  ray  vacuum  electrodes.  In  addition 
there  were  a  sufficient  number  of  .r-ray  applications  for  diagnosis  and 
treatment  to  produce  an  effect  in  a  case  amenable  to  them.  There 
was  marked  improvement  for  awhile,  but  never  complete  disappearance 
of  pain,  and  at  the  end  of  a  thorough  trial  the  treatment  was  abandoned. 
The  severity  of  the  symptoms  and  the  patient's  poor  general  condition 
led  to  the  conclusion  that  some  very  grave  though  obscure  malady 
existed.  Death  ensued  and  an  autopsy  revealed  a  tumor  of  the  right 
parietal  part  of  the  brain  with  considerable  softening  around  it. 


Leonard1   applied  the  .r-ray  in 


>f  migraine,   tie   douloureux, 


and    facial    neuralgia,    generally   with   success.     There   was   recurrence 

in  one  or  two  cases,  but  in  most  cases  the  relief  seemed  to  be  permanent. 

Tumor  of  the  sphenoid  shows  distinctly  in  both  the  lateral  and  an- 

teroposterior  radiographs  of  a  case  now  under  treatment  with  the. r-ray. 


Fit:.  Mv — Tumor  <>f  the  sphenoid.      An  .r-rav  apnlicatioti  from  in  front.      Pan  of  a  cross- 


'i<i-ure  sis  shows  the  application  from  one  of  the  many  different  direc- 


tions necessarv  to  secure  sufficient   deep  effect   by  a  cross-fire  method. 


.v-RAY   APPLICATIONS   AFTER    NERVE   RESECTION   FOR    TIC   DOULOUREUX 

A  case  recently  under  treatment   bv  the  author  was  referred  by  l)r. 

A.  II.  Kly  after  operation  by  |)r.  Harvey  (  'ushinu'.      A-  ureat  a  portion 

as  practicable  ot   the  interior  dental  nerve  had  been  resect etl  from  the 

in>ide  of  the  month.      Six  months  later  there  had  been  >oine  return  of 

:  M  ft  lira]  Hi  cord.  Julv  1.1.  P.m.-. 


1104  MEDICAL    KLECTHICITY    AND     KO.NTGKN     HAYS 

pain,  hut  not  much  return  of  sensation  in  the  portion  of  tin1  lip  supplied 
by  the  inferior  dental  nerve.  A  few  months  ago  .r-ray  treatment  was 
begun,  with  a  view  to  a  retarding  influence  upon  the  regeneration  of  the' 
nerve  and.  if  possible,  to  prevent  bridging  over  the  g;ip  by  newly  formed 
nerve-fibers. 

The  application-  have  been  made  both  externally  and  inside  the 
mouth.  For  both  the  .r-ray  tube  has  been  enclosed  in  a  Ripperger 
shield  and  a  cylinder  diaphragm  has  been  used.  The  distance  from  the 
anticathode  of  the  Friedlander  heavy  anode  tube  (same  model  as  the 
Miiller  No.  13)  to  the  outer  or  inner  surface  of  the  jaw  has  been  13 
inches.  A  12-inch  induction-coil  was  used  with  the  110- volt  direct 
current,  a  Wappler  mechanical  interrupter,  12-ohm  resistance  in  rheo- 
stat, 3  amperes  primary  and  1  ma.  secondary  current.  Rays,  No.  6 
Benoist.  In  the  course  of  twelve  days  the  application  was  of  sixteen 
minutes'  duration,  on  an  area  3  inches  in  diameter  on  the  outside  of 
the  face  and  ten  minute's  on  an  area  1  inch  in  diameter  on  the  inside  of 
the  jaw.  Three  minutes  of  either  application  was  equal  to  1  Holzknecht 
unit.  The  first  course  of  treatment  then  applied  0  H.  externally  and 
3\  II.  internally  in  six  different  applications  made  during  twelve  days. 

The  effect  from  some  of  the  earlier  applications  was  to  cause  com- 
plete disappearance  of  the  pain,  but  the  later  applications  of  the  first 
course  of  treatment  were  followed  by  a  sort  of  stimulation  of  the  nerve, 
causing  temporary  pain. 

The  pain  at  every  stage  of  the  case  came  in  paroxysms,  and  was 
located  immediately  behind  the  last  lower  molar  tooth.  The  patient 
said  it  was  just  as  if  the  lighted  head  of  a  match  had  broken  off  and 
landed  on  the  gum.  Treatment,  in  another  city,  by  radium  and  by  the 
.r-ray  had  been  unsuccessfully  tried  before  an  operation  was  resorted  to. 

There  seems  reason  to  hope  for  success  from  the  application  of  the 
.r-ray  after  resection  of  the  nerve,  but  the  value  of  the  method  has  not 
yet  been  proved. 

Treatment  was  begun  Feb.  S,  ]!)OS,  and  as  far  as  practicable  has 
consisted  of  a  series  of  courses  of  treatment,  during  which  (j  Holzknecht 
units  have  been  applied  bot  h  out  side  and  inside  in  about  three  weeks,  and 
then  an  intermission  of  three  weeks  has  been  allowed.  On  July  20.  1!K)S 
the  outlook  seemed  very  favorable,  and  the  patient  passed  the  first 
entirely  comfortable  dav  for  over  a  year.  Twinges  of  pain  when  thev 
did  occur  were  much  lighter  than  formerly.  The  patient  characterised 
them  as  xcHstitifinx  rntln  r  Hi/in  /min.  A  vacation  from  treatment  during 
the  summer  was,  followed  by  a  recurrence,  which  did  not  yield  promptly, 
and  the  pat  H 'tit  abandoned  treatment  and  had  an  operation  by  alcoholic 
injection,  which  I  believe  has  given  encouraging  results. 

PROSTATIC   HYPERTROPHY 

The  author  ha-  treated  -everal  cases  and  in  some  a  tew  .r-ray  treat- 

liave  produced  a  marked  reduct  ion  in  I  he  a  mount  ot  residual  urine 

•  turn  of  the  abihtv  to  urinate  without  a  catheter.     The  method 

,  allowing  the  .r-ra  v  !o  shine  over  I  he  perineum  in  t  he  direct  ion 

late,    the   scrotum.   ailUS,   and    bullock-   being    protected    by   a 

I hield    surrounding    the    .r-ray    lube.      Mild    application.-    of 

•   netratinir  ray.    No.  7    IVnoi-t.  (i-inch    -park  and  3   ma.,  two 

'  :    3  mm.  aluminum  at  a  distance  ot   13  niche-,  are  made  every 

otl  <i    as    tii    apply    .">    [lol/knecht    unit-    in    about    two    weeks. 

Treat  m    '  '    •  intermitted  upon   the  appearance  of  >li<iht    redness. 


RONTGENOTHERAPY  1  lit") 

There  is  no  danger  of  inducing  sterility  if  the  x-ray  docs  no!  shine 
directly  upon  the  testicles.  Men  for  whom  the  author  has  had  to 
make  long  and  strong  applications  to  one  testis  while  shielding  the 
othei-  with  -heel  lead  ha\'e  subsequently  married  and  had  strong 
healthy  children. 

In  one  of  the  author's  cases  nocturnal  incontinence  of  urine  per- 
sisted lon»-  after  the  use  of  the  catheter  was  obviated.  This  annoying 
.symptom  was  cured  by  applications  of  the  high-frequency  vacuum 
electrode  to  the  scrotum  and  penis  exactly  as  for  a  case  of  impotence. 

Moskowicz  and  Stegmann1  report  0  cases  treated  successfully. 
At  the  end  of  one  or  two  weeks'  treatment  the  prostate  became  softer 
and  a  little  sensitive  to  pressure.  Most  of  their  patients  had  some  un- 
comfortable symptoms  for  a  time,  frequent  desire  to  urinate,  a  sensa- 
tion of  weight  in  the  perineum,  and  sometimes  rectal  tenesmus.  Some 
cases  also  showed  an  increase  in  the  existing  cystitis,  an  increase  in  the 
amount  of  pus,  and  even  a  little  blood  in  the  urine.  One  patient  de- 
veloped slight  epididymitis.  All  these  symptoms  were  slight  and  of 
short  duration.  They  were  attributed  to  an  irritation  caused  by  the 
rapid  destruction  of  the  glandular  epithelium.  In  some  cases  there  was 
the  same  temporary  toxemia  which  characterizes  the  application  of  the 
.r-ray  in  cancer  and  leukemia,  but  this  also  was  mild. 

All  their  cases  were  successful,  but  the  most  rapid  cases  were  those 
which  had  only  been  compelled  to  use  a  catheter  for  a  short  time  and 
who  had  not  developed  cystitis  or  vesical  paralysis. 

Moskowic/  and  Stegmann2made  their  applications  through  a  Kelly 
rectoscope  !)  cm.  long  and  with  its  inner  end  cut  obliquely  so  as  to  expose 
a  larger  surface.  The  rectoscope  is  held  in  place  by  strips  of  adhesive 
piaster  and  the  neighboring  surface  is  protected  by  sheet  lead.  The 
.r-rav  tube  is  placed  so  that  its  anticathode  lies  in  the  direction  of  the 
axis  of  the  rectoscope  and  at  a  distance  of  40  cm.  (Hi  inches)  from  its 
orifice.  Their  exposures  lasted  fifteen  minutes,  and  two  or  three  ap- 
plications were  made  at  intervals  of  two  or  three1  weeks. 

Drs.  Turaschi  and  Carabelli8  report  several  cases  treated,  with  fine 
re-nits.  Their  method  was  by  application  over  the  perineum,  protect- 
ing the  scrotum  from  the  rays. 

Applications  at  either  side  of  the  coccyx  are  preferred  by  Kotera,3  who 
reports  15  cases  successfully  treated.  The  filters  used  we're  3,  4.  or  5 
mm.  of  aluminum;  5  II.  to  each  zone1  was  applied  once  or  twice  a 
month.  In  some  10  or  15  II.  to  each  /one  was  applied  once  in  two  or 
three  months.  There  was  no  skin  reaction,  but  some  bladder  and 
pn  »s1  ale  react  ions. 

My  o\vn  cases  of  tubercular  and  other  prostatitis  were  treated  with 
the  patient  lying  upon  his  back,  the  legs  bent  up,  and  the  hips  near  the 
edge  of  the  table.  A  locali/ing  shield  enveloped  the  .r-ray  tube  and  af- 
forded general  protection.  The  exact  area  of  application  was  secured 
by  culling  a  suitable  orifice  in  a  sheet  of  .r-ray  metal  spread  over  that 
part  of  l  lie  pat  ient . 

A  sole-leather  disk  covered  the  orifice  of  the  localizing  >hield  and 
arrested  the  less  penetrating  rays,  which  otherwise  would  have  been 
absorbed  by  the  skin  and  wmiM  have  produced  irritation. 


119ti 


MKDICAL    ELKC'THICITY    AND    RONTGEN    KAYS 


X-RAY  TREATMENT  OF  GOITER 

The  method  of  aplication  is  to  allow  rays  of  a  medium  degree  of 
penetration  1X0.  G  or  7  Henoist)  to  shine  upon  the  front  and  sides  of  the 
neck  from  two  or  three  different  directions.  A  localizing  shield  is  used 
to  limit  tlu^  rays  to  the  proper  region,  and  a  solo-leather  disk  may  be 
used  to  absorb  the  less  penetrating  rays.  It  may  be  necessary  to  wrap 
the  chin  in  shrct  lead,  and  it  may  be  wise  to  cover  one  side  of  the  neck 
with  sheet  lead  while  the  other  side  is  being  treated.  It  is  difficult, 


M.      r-H:iv  r n-;it im-ul  of  cxoiiht liiihiiir1  n<>itcr.      Brickiicr  .-<  tunr-stnml.      !•  nr-dlandcr 


'uint  of  clnii  Mill  further     rotccti-il  1  >     .r-ni      met 


i'h  tlic  loe:ilixer  alone,  to  limit  t  he  ray  <o  exactly  t  hat  1  here  will  not  be 
efted   al<>n:i  the  median  line  ti'om  t  \v<  >  successive  anterolatenil 
in  •-. 

Mild  n  pea  ted  exposures  tire  to  be  preferred      ',  ti  i  1   II.  twice  a  week. 

livalen!    t<>  .i-inrh   spark.   -  ma.   for  1\\'o  1o  four  minutes  at 

el     In    !:"-he-    tmni    the   antieathode.       |-]aeh    of    the    l\v<>   or 

-U!'laee  -ueee— i\'ely  expired   i-  t«i  ha\'e  \\\\<  ainoiint   <if 

t  rea  t  tn  ••       ---ion. 

-!>me\vha1     iiii<-ert  ain,    alt  luni»Ii    the    treatment     i.- 


RONTGENOTHERAPY 


1197 


successful  in  a  sufficient  proportion  of  the  cases  to  cause  it  to  bo  recom- 
mended. 

An  experiment  was  performed  by  Drs.  Luraschi  and  Fiorentini  upon 
three  puppies,  all  of  whom  had  goiter.  One  of  them  was  killed  and  the 
tumor  examined  under  the  microscope.  Another  was  kept  as  a  control 
and  the  third  was  subjected  to  x-ray  treatment.  This  one  died  of 


IL:.  N_'U. — Exophthalmic  goiter.     Treatment  by  high-frequency  currents  applied  l>y  ultra- 


asphyxia  after  a  few  treatments,  and  a  microscopic  examination  showed 
that  the  .r-ray  had  produced  no  effect  upon  the  goiter.1 

Michaux  has  treated  cases  of  u'oiter  and  obtained  results  in  the  hy- 
pertrophic  variety,  but  the  growth  recurred  when  the  treatment  was 
stopped." 

Kobolko,  on  the  other  hand,  reports  a  case  of  goiter  cured  by  the 
x-ray. :! 

A  glandular  swelling  in  the  neck  may.  of  course,  be  one  of  the  lesions 

1  Le  Radium.  Sept.  LI,  I'.MIo.  p.  300. 
-  Ibid. 
'  Ibid. 


119S  MF.DK  AL    KI.K(  TKH  ITV    AM)    H(")XT(iKN    KAYS 

of  leukemia  or  pseudoleukemia,  and  in   that   case  the  x-ray  produces 

pi isit ive  results. 

Two  other  cases  of  goiter  have  been  treated  with  benefit  by  Steg- 
niann.1  Six  treatments  in  one  case  and  two  in  the  other  led  to  softening 
and  reduction  in  si/e  without  any  systemic  disturbance. 

Steu'mann  did  not  notice  the  special  susceptibility  of  the  skin  to 
the  .r-ray.  which  has  been  described  by  (lorl. 

Exophthalmic  Goiter. -•  Many  successful  cases  have  occurred  in 
the  practice  of  the  author  and  others.  Every  case  should  have  an  .r-ray 
examination  of  the  teeth.  The  presence  of  a  badly  infected  tooth  will 
interfere  with  the  cure.  Mild  repeated  applications  of  the  .r-ray 
over  the  thyroid  gland  and  of  a  vacuum  electrode  from  the  (  hulin  resona- 
tnr  over  the  (nit ire  neck  resulted  in  the  cure  of  a  case  brought  to  the 
author  by  Dr.  Love.  Before  treatment  the  pusle  was  never  below  1W): 
there  was  such  a  tremor  of  the  hands  that  she  could  not  pour  a  cup  of 
tea.  and  such  palpitation  of  the  heart  that  it  shook  the  whole  bed  and 
kept  her  husband  awake  at  night. 

Treatment  was  continued  for  about  three  months,  and  when  the 
patient  returned  to  her  home  in  North  Carolina  her  pulse  was  90  and 
all  the  ocular  and  nervous  symptoms  had  disappeared.  The  thyroid 
gland  had  diminished  in  size.  It  had  never  been  very  large. 

No  recurrence  took  place  even  during  a  period  of  great  anxiety  over 
her  sick  child  the  following  year.  The  patient  was  examined  three  years 
later  and  was  perfectly  well. 

The  method  of  application  of  the  .r-ray  is  shown  in  Fig.  819  and  of 
the  high-frequency  current  in  Fig.  820. 

Death  After  x-Rau  Treatment  of  Exophthalmic  Goiter. — Yerning2  re- 
port- 2  recent  cases  a  month  from  onset;  both  received  5  H.,  repeated 
after  one  or  two  days.  All  symptoms  were  aggravated  and  death 
occurred  in  fifteen  and  forty-two  days. 

Rontgenization  of  the  suprarenal  capsule  in  high  arterial  tension 
produces  a  decided  fall  and  an  improvement  in  the  symptoms/' 

PERNICIOUS  ANEMIA 

This  is  a  disea>e  in  which  the  effect  of  the  .r-ray  upon  the  blood- 
forminu'  '  iriians.  t  he  spleen,  and  t  he  marrow  of  the  long  bones  may  some- 
times  be  of  great  benefit.  The  danger  of  causing  toxemia  and  possible 
d'-at  1 1  make-  it  necessary  to  Use  extremely  small  doses  at  the  commence- 
ment, and  some  ob.-ervers  <  1'ancoa-t  >  consider  the  x-ray  absolutely 
'•'  ail  r.-tindicated  on  account  of  the  danger.  Injections  of  diphtheria 
antitoxin  in  addition  to  the  x-ray  have  been  used  successfully  by  Henon 
and  Teixier.4 

iiODGKIN'S   DISEASE   AND   PSEUDOLEUKEMIA   AND    LYMPHOSARCOM  A 

licenses   iii   which    ./'-ray   applications   to   the   affected 


RONTGENOTHERAPY  1 199 

tumor  which  diminished  one-third  in  ten  hours  mid  was  all  gone  in  six 
months,  and  hemoglobin  was  raised  (>0  to  90  per  cent.  The  beneficial 
effect  of  the  .r-ray  is  due  to  a  direct  action  upon  lymphoid  tissue  and 
to  an  effect  upon  tissue  ferments  (Kdsall).  The  affected  lymphatic 
glands  become  a  great  deal  smaller  and  the  microscopic  appearance 
is  changed.  There  is  a  destruction  and  disintegration  of  lymphocytes 
with  the  presence  of  masses  of  chromatin  derived  from  their  nuclei. 
The  gland  may  finally  change  to  a  fibrous  nodule. 

In  a  case  of  Ilodgkin's  disease,  treated  by  Roth,1  the  glands  were 
reduced  to  a  normal  si/e  by  .r-ray  treatment  everv  other  day  for  about 
three  months.  A  medium  hard  tube  was  used,  with  the  anticathode  at  a 
distance  of  JO  inches  from  the  skin  over  the  neck  and  nianubrium  sierni 
(there  were  enlarged  mediast  inal  glands),  and  the  duration  of  each 
exposure  was  from  ten  to  thirty-five  minutes,  divided  up  over  different 
glands.  Two  or  three  recurrences  took  place  requiring  fresh  courses  of 
treatment.  Seim  and  Pusey  were  among  the  earliest  to  treat  these 
conditions  by  the  .r-ray.  Pancoast  has  collected  the  reports  of  44  cases 
treated  up  to  1907.  and  finds  for  this  general  group  of  diseases  of  the 
lymphatic  glands  without  marked  blood  changes  ./--ray  treatment  in  29 
cases,  of  which  the  final  outcome  is  known,  has  given  25  per  cent,  of 
cases  which  are  alive  and  apparently  well  from  one  to  four  years  after 
the  first  symptomatic  cure,  and  (10  per  cent,  have  died,  while  2  of  the 
4  cases  still  under  treatment  are  likely  to  die  and  the  other  2  seem  likely 
to  get  well. 

Rosenberger2  has  treated  one  case  of  pseudoleukemia  with  some 
reduction  in  the  size  of  the  spleen,  but  without  much  general  benefit. 

Two  cases  of  pseudoleukemia  treated  by  Krause;)  showed  prompt 
improvement,  while  no  result  was  obtained  in  2  cases  of  lymphosar- 
coma.  1  ease  of  splenic  anemia,  and  .'•>  cases  of  chronic  splenomegaly. 

Jn  no  case  did  the  treat  men t  have  any  serious  secondary  effect. 

'Two  methods  of  dosage  are  available.  According  to  one  method, 
.'5  to  4  Hol/knecht  units  of  rays  Xo.  S  Benoist  should  be  applied  over 
each  glandular  mass  once  a  week  unless  contraindicated  by  the  ap- 
pearance of  dermatitis.  According  to  the  other  method,  smaller  doses 
of  I  llol/knecht  unit  should  be  applied  over  each  glandular  mass  three 
times  a  week. 

\\hen  using  either  met  hod  exposure  of  the  abdomen  should  be  under- 
taken with  caution.  There  is  not  ihe  same  special  danger  ot  toxemia 
as  in  leukemia,  but  still  the  danger  is  great  enough  to  make  it  desirable 
to  ascertain  the  condition  of  the  kidneys  before  making  the  exposure, 
and  t  he  first  one  should  be  short . 

The  distance  and  the  strength  of  current  and  duration  of  exposure 
mentioned  under  the  head  of  Leukemia  (p.  1205;  are  suitable1  here. 

The  dilliciiltv  "f  differential  diagnosis  between  lymphosarcoma 
and  Ilodgkin's  disease  add-  a  further  element  to  the  uncertain  prog- 
nosis which  must  be  given  in  these  cases. 

POLYCYTHEMIA 

T  he  results  of  .r-rav  t  real  men  t  in  this  disease  have  not  been  decisive, 
but  .-till  .r-ray  exposures  of  the  splenic  area  have  produced  some  im- 
provement and  no  accidents  in  4  reported  cases. 


MKDU'AL    KLKITKICITY    AXI)    UOXTCKX    HAYS 
A'-RAY   TREATMENT   OF   LEUKEMIA 

The  credit  of  first  reporting  the  treatment  of  a  case  of  leukemia 
!>y  the  .r-ray  is  generally  accorded  to  Semi,  but  Pusey,  Childs,  Dunn,  and 
others  treated  cases  at  about  the  same  time.  The  treatment,  therefore, 
is  of  American  origin,  hut  it  has  been  adopted  in  every  country  and  has 
been  made  the  subject  of  over  one  hundred  articles  by  various  authors. 

It  was  at  once  found  that  the  majority  of  the  cases  improved  in  a 
most  remarkable  way  if  the  .r-ray  was  applied  repeatedly  to  the  enlarged 
spleen,  any  enlarged  lymphatic  glands,  and  the  long  bones.  The  num- 
ber of  leukocytes  diminished  from  200. 000  or  more  to  the  normal  4000 
or  5000.  and  the  general  condition  of  the  patients  became  so  much  better 
that  they  were  called  symptomatically  cured.  The  spleen  often  dimin- 
ished to  its  natural  size,  but  this  effect  was  not  so  uniform  as  the  effect 
upon  the  blood  and  lymphatic  glands  and  upon  the  general  condition. 

The  treatment  required  frequently  repeated  application  for  several 
months  or  a  year. 

The  results  were  found  to  be  permanent  in  only  1  case  in  about  15. 
As  a  rule,  recurrence  and  death  took  place.  Then1  were  bad  effects  in 
certain  cases  which  were  described  on  page>  1135  and  1205 

Xevertheless.  the  .r-ray  produces  an  improvement  which  nothing 
else  ever  did.  and  it  seems  to  be  the  proper  treatment  for  this  disease. 
It  is  not  unlikely  that  improvements  in  the  mode  of  application  may 
result  in  saving  more  lives  than  the1  (i  or  S  per  cent,  shown  by  the  record 
to-day.  Pancoast's  method  of  application  to  the  long  bones  instead  of 
to  the  spleen  has  proved  to  be  a  step  in  advance. 

The  close  analogy  between  leukemia  and  sarcoma  makes  it  seem 
|H)shible  that  leukemia  also  will  prove  to  be  incapable  of  permanent 
cure  in  the  great  majority  of  cases.  This  is  a  point  which  the1  future 
will  decide.  It  does  not  at  all  imply  that  the  .r-ray  is  not  the  best  treat- 
ment that  we  know  of.  The  .r-ray  ought  to  be  applied  in  ('very  case 
unless  contraindicated. 

.r-Kay  applications,  in  leukemia  suppress  fever  when  this  is  present, 
and  also  night-sweats,  apathy,  and  anorexia.  Asa  rule,  the  cachectic 
appearance,  the  color  and  dyspnea,  and  insomnia  all  begin  to  improve1 
in-ide  of  two  weeks.  Albuniinuria.  if  present,  rapidly  disappears,  but 
edema  is  sli  i\ver. 

The  .r-ray  is  more  constant  in  its  result-  upon  the  myeloid  than  upon 
the  lymphoid  variety  of  leukemia. 

The  author'-  cases  show  a  marvelous  disappearance  of  the  glandular 
-wellinu-  following  direct  .r-ray  application-,  also  very  great  improve- 
ment in  the  blood  count  and  almost  complete  disappearance  of  the 
-plenic  tumor.  It  should  be  noted  in  the  latter  connection  that  while 

a-ional  direct  application-  to  the  spleen  are  usually  required,  they 
ot  moderate  do-aize.  They  are  followed  by  diarrhea  and  a 
amount  of  depression  la-ting  a  few  day-.  The  author  has  had 
1  ot  permanent  cure,  but  -everal  of  wonderful  temporary  benefit . 
ifn!  i /ift  cl  inn  \va-  a  hiiihly  po--ihle  causative  factor  in  one  fatal 
i  which,  however,  there  \va-  a  -tronu  familial  cause  as  well. 

Examples  of  the  Results.  Kr.-nise1  reports  the  treatment  of  li 
case-  iii  myelou'enous  leukemia:  •>  ot  these  showed  rapid  improvement, 
reduction  in  the  number  ot  leukocyte-,  increased  number  of  red  blood- 

!'••  rlitl     klJTi.    \Vnrl,..    M;iY   S,    I1. Hi.".,   p.   .X):   iwirwr.l   in    HadilUIl,   Sept.    1.' 


RONTGENOTHERAPY  1201 

cells,  increased  globular  value,  diminution  or  complete  disappearance 
of  the  splenic  tumor,  increased  bodily  weight,  marked  improvement 
In  general  health.  The  remaining  case  of  myelogenous  leukemia  was 
complicated  by  hemorrhagic  nephritis  and  was  not  influenced  by  the 
.r-ray  treatment. 

Out  of  4  cases  of  leukemia  (myelogenous?)  treated  by  Mclland,1  3 
were  benefited  by  the  .r-ray. 

Ilynck2  has  not  obtained  permanent  results  from  the  treatment  of 
leukemia  (myelogenous?)  with  the  x-ray,  but,  at  the  same  time,  the 
condition  of  the  blood  and  the  spleen  showed  the  improvements  noted 
by  other  observers,  and  there  was  the  same  improvement  in  the  general 
health. 

Rosenbach3  believes  that  the  reduction  in  the  number  of  leukocytes 
is  not  due  merely  to  the  destruction  of  leukocytes  and  erythrocytes  in 
the  blood,  but  also  to  the  migration  of  great  numbers  of  leukocytes  into 
the  irritated  skin  and  subcutaneous  connective  tissue.  The  products  of 
the  destruction  of  t  he  leukocytes  probably  have  an  inhibitor}-  effect  upon 
the  production  of  leukocytes, 

According  to  Rosenbach,  the  .r-ray  acts  upon  a  symptom,  not  upon 
the  cause,  of  the  disease.  He  thinks  it  may  even  be  that  the  great 
number  of  leukocytes  is  a  defensive  provision  of  nature  in  this  disease. 

A  case  of  splenomyelogenous  leukemia  was  treated  by  Roth4  by 
r-ray  applications  over  the  spleen  and  the  long  bones  alternately. 
The  primary  effect  of  the  .r-ray  was  to  increase  the  number  of  white  cells, 
which  reached  its  maximum  five  hours  after  each  exposure.  The  num- 
ber of  leukocytes  steadily  increased  from  loo. 000  before  treatment  to 
:>7vOOO  after  the  first  month's  treatment.  From  this  time  on  there 
was  a  stead}"  fall  in  the  number  of  leukocytes,  aided  toward  the  last 
by  the  use  of  Fowler's  solution  of  arsenic.  After  a  year's  .r-ray  treat- 
ment, and  a  month  after  the  arsenic  had  been  stopped,  the  leukocyte 
count  was  normal,  but  the  size  of  the  spleen  was  not  greatly  changed. 
The  primary  increase  in  the  number  of  leukocytes  was  accompanied  by 
a  great  number  of  degenerate  cells,  principally  disintegrating  myelocytes, 
which  in  man}  cases  consisted  merely  of  a  network  of  iibrilhe.  The 
amount  of  hemoglobin  remained  uniform  at  70  per  cent,  during  a  whole 
year's  .r-ray  treatment,  but  promptly  rose  to  SO  per  cent,  when  ai>eiuc 
was  added  to  the  treatment.  The  dosage  of  the  latter  was  at  first  o 
Fowler's  solution  three  times  a  day.  and  this  was  u'radually 
!o  \~i  t  Imps  t  hive  1  nne-  a  day. 

mail"  finds  that   .r-ray  applications  reduce  the  number  of  leu- 
and  t  hat   t  his  is  due  part  ly 
ig    in    the    blood,    the    effect 
re>pond   to  basic  dyes. 
1  he  marrow  of  1  lie  b< mes. 


1  he  effect  of  long  .r-ray  exposure  M  hree  to  fiv 


1  Hriii-h  Mc.l.  Jour.,  July,  !'.»<).-,. 

-  Wiener  Med.  \Vnch.,  June  10.  1005. 

•'  Mi'mrli.  Med.  \\Mi-h..  May  :;n.  1  !»().">.  p.  11).')."):  reviewed  in  Radium,  Sept.  !.'>.  l!)0.">. 

4  Jour.  Amor.  Med.  Assoc."  Oct.  •_'(>.  I'.'Oti 

5  Briti.-h  Med.  .lour..  July  1  1,  I'.MHi. 

6  American  Medicine,  Dee.  '_'.  1<M>">. 

7t> 


1202  MEDICAL    ELECTRICITY    AND    ROXTGEX    RAYS 

of  leukocytes,  the  lymphocytes  being  chiefly  affected.     There  is  no  effect 
upon  the  number  of  red  blood-cells  or  upon  the  amount  of  hemoglobin. 

It  must  be  remembered  that  a  sudden  fall  of  perhaps  200,000  leuko- 
cytes is  not  an  unheard  of  thing  in  leukemia  without  special  treatment. 

Dock'  has  made  valuable  observations  upon  the  clinical  benefit  and 
pathologic  findings  in  cases  of  leukemia  treated  by  the  .r-ray.  He  found 
that  the  myelocytes  rarely  disappeared. 

(iramegna  and  Quadrone2  and  L.  d'Amato3  found  that  .r-radiation  of 
the  spleen  led  to  a  perceptible  increase  in  the  number  of  leukocytes, 
notably  of  lymphocytes,  apparently  by  contraction  of  the  organ. 
The  blood  of  the  spleen  examined  in  3  patients  showed  a  large  pro- 
portion of  lymphocytes,  some  multinuclear  myelocytes.  a  small  number 
of  multinuclear  cells  and  of  myelocytes  and  of  nucleated  red  blood- 
cells,  the  number  being  superior  to  that  found  in  the  circulating  blood. 
The  serum  had  a  slight  agglutinative  action,  but  no  hematologitic  or  leu- 
kocytic  action. 

The  abnormal  relations  between  the  various  forms  of  leukocytes 
persist  even  though  their  total  number  is  so  markedly  reduced. 

Effect  Not  a.  Bactericide  One. — The  benefit  in  leukemia  does  not 
seem  to  be  due  to  a  bactericide  action,  for  the  ;r-ray  is  only  weakly 
effective  in  this  direction,  and  then  we  do  not  know  that  the  disease  is 
of  parasitic  origin. 

Nature  of  the  Beneficial  Action. — The  favorable  effect  of  the  .r-ray 
in  splenic  and  lymphatic  diseases  (including  leukemia  and  pseudo- 
leukemia)  is  explained  by  Krause  and  Ziegler  on  the  ground  that  the 
application  destroys  the  pathologic  lymphoid  tissue. 

Kdsall  attributes  the  beneficial  effect  to  an  action  upon  the  tissue 
ferments. 

The  Nature  of  the  Leukocytosis  in  Leukemia. — Large  lympho- 
cytes form  'JO  per  cent,  of  the  total  number  of  leukocytes;  small  lympho- 
cytes, 4  per  cent.,  polymorphonuclear  leukocytes,  4  per  cent.;  myelo- 
cytes, 2  per  cent.;  eosinophilc,  0.5  per  cent.;  no  basophiles  or  eosino- 
phile  myelocvtes  (Mendelson  and  Soiidem).  These  observers  found  that 
on  the  da}'  of  death  the  large  lymphocytes  fell  to  30  per  cent.,  while  the 
small  lymphocytes  increased  to  o3  per  cent. 

A  simple  count  of  the  number  of  leukocytes  is  not  regarded  as  suffi- 
cient ;  there  should  be  also  a  differential  count  in  cases  of  leukemia  under 
:r-ray  treatment. 

Ledingham4  treated  a  case  of  splenomyelogenous  leukemia  with 
marked  general  improvement  in  the  condition  of  the  blood.  The 
patient  died  of  the  grip,  and  a  post-mortem  examination  showed  that 
Malpighian  corpuscles  were  absent  from  the  spleen  and  that  lymphoid 
tissue  was  very  scarce.  The  most  remarkable  change  consisted  in  the 
substitution  of  proliferating  undifferentiated  basophile  myelocytes  for  the 
fully  formed  neutrophile  cells  usually  found  in  the  spleen  in  leukemia. 

The  profoundness  of  the  changes  in  the  spleen  caused  Ledingham  to 
recommend  caution  in  the  application  of  the  .r-ray  after  the  leukocytes 
had  been  reduced  TO  the  normal  number. 

Holdinu  and  Warreir'  report   temporary  improvement   in  a  case  of 


508. 


RONTGENOTHERAPY 


1203 


pseudoleukemia  and  in  one  of  leukemia.  The  treatment  was  applied 
to  the  spleen,  the  enlarged  glands,  and  the  epiphyses  of  the  long  bones 
(elbows  and  knees  especially).  The  blood  showed  the  improvement 
reported  by  so  many  other  observers.  A  careful  examination  of  the  urine 
showed  an  increased  amount  of  uric  acid  and  a  high  ratio  of  uric  acid  to 
urea  during  periods  of  active1  .r-ray  treatment,  but  Holding  and  "Warren 
were  unable  to  trace  any  relation  between  the  leukocyte  chart  and  the 
urinary  analysis,  as  above,  or  as  regards  the  uric  acid  and  purin  excre- 
tion. 

The  increased  coagulability  of  the  blood  produced  by  x-ray  ex- 
posures has  been  suggested  as  of  possible  value  in  hemophilia  and  other 
hemori'hagic  conditions.1 

Effects  of  ;r-Ray  Treatment  Upon  Excretion  of  Uric  Acid  in 
Leukemia. — The  majority  of  observers,  including  Pancoast,  find  that 
the  amount  of  uric  acid  in  the  urine  is  increased  by  the-  treatment,  and 
regard  the  treatment  as  contraindicated  if  the  amount  of  uric  acid  in  a 
twenty-four-hour  specimen  falls  after  the  .r-ray  exposure. 

It  is  noteworthy,  however,  that  another  observer  has  arrived  at  a 
contrary  conclusion: 

The  reduction  in  the  amount  of  uric  acid  in  the  urine,  which  is  a 
consequence  of  increased  oxidation  and  other  vital  processes,  is  regarded 
by  Rosenberger"  as  an  important  indication  of  the  benefit  of  .r-ray 
application  in  leukemia.  If  the  amount  of  uric  acid  fails  to  be  reduced 
ho  thinks  that  especial  caution  should  be  used  in  applying  this  method 
of  treatment.  According  to  this  observer  there  is  a  change  in  the  ex- 
cretion of  uric  acid  in  cases  of  leukemia  treated  by  the  .r-ray.  The 
amount  is  increased  at  first,  then  diminished,  and  then  returns  to  about 
the  normal.  The  excretion  of  xanthin  is  increased  throughout  the  treat- 
ment, lie  finds  no  such  change  in  the  urine  in  cases  of  pseudoleukemia 
or  diseases  other  than  real  leukemia  treated  by  the  .r-ray. 

Chemic  and  Histologic  Researches  in  Patients  with  Leukemia 
Treated  by  the  .'/'-Rays  (Lossen  and  Morawitz3). — They  record  a  case 
of  myeloid  leukemia  treated  by  .r-rays,  and  in  which  there  was  a  return 
to  the  normal  number  of  leukocytes  at  the  same  time  that  the  excretion 

/       ^* 

of  uric  acid  returned  to  the  average.    (—.  *  — .-,  =  30,  instead  of  13.  as 

\uric  acid 

it  was  at  first.) 

These  facts  indicate  a  diminution  in  the  activity  of  the  tissues  pro- 
ducing leukocytes.  These  authors  insist  on  this  retrogression  of  the 
leukopoietic  functions.  In  certain  case.-,  however,  the  diminution  in 
the  leukocytes  is  not  accompanied  by  a  lowering  of  the  uric  acid  ratio. 
Sometimes  one  can  see  developed  in  patients  treated  by  the  .r-ray 
an  aplastie  leukemia  which  is  dependent  upon  the  hypoplasia  of  the 
leukopoietic  organs  produced  by  the  r-rays. 

Development  of  a  Leukotoxin  from  .r-Ray  Exposure. — Milchener 
and  "Wolff4  found  that  .r-ray  exposure  of  the  spleen  after  removal  from 
the  living  body  produced  a  leukotoxin.  An  extract  of  such  a  spleen 
injected  into  a  healthy  animal  produced  a  marked  reduction  in  the  num- 
ber of  leukocytes,  while  a  similar  injection  from  a  spleen  which  has  not 


1201  MKIHC'AL    KLKH  TKiriTY    AND    HC)XT(iKX    KAYS 

been  .r-rayed  produced  leukocytosis,   increasing  the1  number  of  white 
blood-cells. 

Kxposure  of  living  animals  to  the  .r-ray  produce's  a  reduction  in  the 
number  of  leukocytes,  especially  if  the1  blood-forming  organs,  the  spleen 
and  bone-marrow,  arc1  exposed.  The  fact  that  the  primary  effect  is 
followed  bv  a  renewal  of  the1  number  or  eve'ii  an  increase  over  the  original 
number  of  lenikocytes  is  taken  by  some  authorities  to  indicate  that  the 
eftVc't  is  a  direct  one1  upon  the  leukocytes  and  not  a  depressant  one 
upon  the1  blood-forming  organs.  Other  observers,  like  Iwan  Hosen- 
stern,1  consieler  it  due  to  the'  effect  upon  the1  leukocyte-forming  organs, 
and  that  the  number  of  leukocyte's  is  reduced  not  by  their  destruction, 
but  by  their  greatly  restricted  production. 

The  observations  of  Capps  and  Smith2  show  that  serum  from  a 
leukemic  patient  who  has  been  tivateel  by  the  .r-ray  produces  a  marked 
reduction  in  the  number  of  leukocytes  if  .injected  into  another  leukemic 
patient.  This  leukotoxin  is  strongest  when  the  patient  has  responded 
best  to  .r-ray  treatnu-nt.  The  action  is  selective,  a  (fee-ting  mononuclear 
leukocytes  more;  than  pe>lynuclear  ones.  Its  repeated  injection  into 
another  patient  proeluces  a  kind  of  immunity,  so  that  it  is  not  followed 
bv  as  gre-at  a  reduction  in  the  number  of  leukocytes  as  it  e-aused  at  first. 
This  same  serum  possesses  marked  leukolytic  and  agglutinating 
effects  upon  blood  rn  rilro.  Phagocytosis  is  not  affected  by  the  serum 
from  a  patient  who  has  bevn  .r-rayed. 

Accidents  Which  Have  Followed  x-Ray  Treatment  in  Leukemia. 
— X-i'ni/  (Icrnidtilix  over  the  spleen  has  bevn  observed  by  so  many 
operators  that  it  seems  as  if  some}  special  susceptibility  must  exist. 
One  precaution  which  may  be  taken  consists  in  the  use  of  a  screen  of 
leather,  wet  or  dry,  or  o  mm.  of  aluminum,  as  a  means  of  arresting 
the  soft  rays,  which  would  otherwise1  be  absorbed  by  the1  skin  and 
set  up  dermatitis  and  which  have  no  curative1  influence1  in  leukemia. 
The  position  of  the  tube  has  a  great  deal  to  do  with  the  e'l'fecl  upon  the 
skin.  In  some  reported  cases  the  .r-ray  tube  has  been  placed  10  cm. 
'  I  inches)  from  the  Mirface  of  the  body.  A  burn  was  a  natural  conse1- 
qiience  if  enough  .r-ray  was  applied  to  affect  the  deeper  part--  of  the 
spleen,  -ituated  two.  three,  or  four  times,  as  far  from  the  .r-ray  tube1. 
I  he  rays  an-  then  four.  nine,  or  six!  ecu  times  as  concentrated  at  t  he  skin 
irface  as  they  w<  mid  be-  a  1  t  lie  deeper  parts  of  the  spleen  if  t  he  mat  ter  of 

we  have  added  t  he  effect   of 
The  anticathode  should  be  placed 
he    cutaneous   surface    in    treating 
a    fan'    degree    (>f    penetration, 
ol    vital  importance,   and  either  long 
ans  of  measurement  as  t  he  Sa bo ura  ud 
inteiisimet  ric  unit  s  should  be  de- 
o  apply  the  .r-ray  even  for  what 
nis  it  he  has  no  means 
It   is  like  administering 
ked  ''  Solut  ion  of  Mor- 
solut  ion,  of  which  a  tea- 
>r  hypodermic  adminisl  ra- 
iconscious  and  a  tea- 
ir  may  know  t  hat  wil  h  his 

p.  loot;. 


RONTGENOTHERAPY  1 205 

apparatus  regulated  in  a  certain  way,  so  as  to  give  a  certain  number  of 
amperes  with  a  certain  rate  of  interruption  in  the  primary  current  and  a 
certain  resistance  in  thetube  result  ing  in  a  certain  numlxTof  milliamperes 
of  secondary  current,  a  certain  number  of  minutes'  exposure  at  a  certain 
distance  constitutes  a  desirable  application.  This  knowledge  he  may  have 
gained  by  experience  or  by  the  use  of  the  quantitative  or  intensimetric 
systems  so  often  referred  to  in  this  book.  If  he  does  not  know  the  safe 
dose  of  the  rays  generated  lie  had  better  make  the  quantitative  or  inten- 
simetric measurements  for  the  special  cast;  in  hand.  The  theory  that 
the  .r-ray  does  not  burn,  but.  rather  an  electrostatic  or  condenser  con- 
dition of  the  air  separating  the  .r-ray  tube  from  the  skin,  and  that  burns 
may  be  prevented  by  placing  the  .r-ray  tube  at  the  proper  distance 
(10  inches)  to  overcome  this  effect,  is  not  to  be  relied  upon  to  the 
neglect  of  proper  dosage.  Burns  have  occurred  in  cases  in  which  this 
theory  as  to  distance1  has  been  exclusively  depended  upon.  The  cumu- 
lative effect  of  the  .r-ray  is  always  to  be  borne1  in  mind.  Exposures 
which  individually  might  produce1  no  visible  effect  might  produce1  bad 
burns  if  repeated  day  after  day  for  a  great  many  weeks.  This  is  where 
the  exact  Knowledge  of  dosage  is  most,  important. 

A  case  of  Licbermeister's,  a  woman  of  sixty,  showed  cardiac  weakness 
and  additional  swelling  of  the  glands  and  elied  after  .r-ray  exposure  for 
llodgkin's  disease.  Pleurisy  with  effusion  followed  .r-ray  exposure  for 
leukemia  in  two  of  Quadrone's  patients.  Such  accidents  as  these 
suggest  caution  in  commencing  this  treatment  upon  a  new  patient 
whose  degree  of  susceptibility  is  unknown. 

The  toxemia  which  often  follows  .r-ray  exposures  in  this  disease, 
and  which  has  been  made  the  subject  of  admirable  studies  by  Eelsall  and 
others,  is  dese-ribeel  on  p.  1135.  A  case  in  which  Pancoast  made  a  single1 
radiographic  exposure  of  eight  see'onds  preliminary  to  any  therapeutic 
application  showed  pronounced  and  almost  fatal  toxemia,  This  con- 
dition appears  to  be  due  to  the  inability  of  the  kidneys  to  remove  the 
enormously  increased  products  of  destructive1  metabolism.  It  may  be 
guarded  against  in  two  ways:  First,  by  making  sure  that  the  kidneys 
are  in  a  healthy  and  active1  condition  before  applying  the  .r-ray,  and, 
second,  by  commencing  with  extremely  small  doses.  Pancoast's 
suggestion  as  to  avoiding  the  sple'en  in  the  first  few  weeks  or  months  of 
.r-ray  treatme-nt  for  leukemia  certainly  tends  to  prevent  the  occurrence 
of  extreme  toxemia,  though  this  is  not  its  only  object. 

In  occasional  cases  of  leukemia  treated  by  the  .r-ray  a  rapidly  fatal 
fun  ini/i  has  followed. 

Contraindications. — The  .r-ray  comes  into  play  especially  in  cases 
where  abnormal  cellular  activity  and  development  are- taking  plae-e.  and 
is  contraindicated  where  profound  depression  of  cellular  life  has  taken 
place,  as  in  the  marrow  of  the  long  bones  in  pernicious  ane'inia. 

I iixu  t/irit  ni"i/  of  Ten dl  act/ rih/  is  a  contraindication. 

Technic  of  ,r-Ray  Application  for  Leukemia. — Two  principal 
methods  have1  been  used  for  the  application  to  the1  spleen  and  the  ein- 
la  I'ged  glands:  (1)  Helot  and  ot  hers  in  Europe  make  applical  ions  of  -I  or  5 
1 1 ol /kneel it  units  oveT  the  en t  ire  surface  of  the  spleen  once  a  week  tmi  il 
stopped  bv  the  development  of  dermatitis,  whirh  seldom  occurs.  To 
secure  uniformity  of  eft'eH  the  tube  is  about  s  inches  from  the1  skin  and 
t  lie  surface  is  .r-ray ed  m  four  .-ec!  ion.-,  i  hrec  benur  protected  \\  Itile  one  is 
exposed.  The  entire  four  sections  are  treated  at  the1  same  session. 


1206  MEDICAL    ELECTRICITY    AND    RONTGEX    RAYS 

Belot  has  not  observed  any  oases  of  toxemia  from  this  method,  hut  in 
America  it  is  regarded  as  extremely  hazardous  in  an  untried  patient. 
Fatal  toxemia  has  been  observed  from  a  single  application  of  this 
strength  in  leukemia.  There  is  not  so  much  danger  in  the  same  appli- 
cation to  the1  lymphatic  glands,  but  even  here  it  is  risky  at  the  first 
treatment.  ('2)  The  method  of  daily  application  of  fractional  doses 
of  about  \  to  I  Holzknecht  unit  over  the  spleen  and  lymphatic  glands  is 
usually  safe,  provided  the  urine  has  been  analyzed  and  the  kidneys 
found  to  be  normal. 

The  rays  should  have  a  penetration  of  about  Xo.  7  Benoist,  and  an 
example  of  technic  producing  .1  II.  is  as  follows: 

Muller  heavy  anode  tube  0  inches  in  diameter,  12-inch  induction- 
coil  with  great  self-induction;  Caldwell  interrupter,  S  amperes  current, 
2  ma.  secondary  current;  Xo.  ,s  Benoist,  3j  inches  parallel  spark-gup, 
1  anode  used;  no  rheostat  resistance:  distance  from  anticathode  to 
skin  12  inches:  an  exposure  of  three  minutes  equals  \  H. 

An  exposure  of  six  minutes  under  the  same  conditions  equals  1  H. 

The  daily  dose  varies  between  these  amounts  in  different  cases. 

The  duration  of  exposure  would  be  doubled  if  the  treatment  were 
given  only  every  two  days. 

Another  example  of  dosage  employs  the  same  :r-ray  tube  and  coil,  a 
Wappler  mechanical  interrupter,  3  amperes  of  primary  current,  1  ma. 
of  secondary  current,  rays  Xo.  o  Benoist,  resistance  3  inches,  12  ohms 
rheostat  resistance,  no  spark-gap,  anticathode  and  accessory  anode, 
connected  distance  from  anticathode  to  skin  12  inches:  an  exposure  of 
five  minutes  equals  about  1  Holzknecht  unit. 

Another  example  of  dosage  (quoted  from  Paneoast)  employs  a  hard 
tube,  resistance  4  inches,  an  induction-coil  with  a  mechanical  spring 
interrupter,  and  a  secondary  current  of  1  ma.  Four  minutes' exposure 
over  the  abdomen  at  a  distance  of  !)  or  10  inches  is  a  very  mild  exposure, 
but  .-till  was  enough  to  cause  profound  toxemia  in  a  case  of  pernicious 
anemia.  Ten  or  fifteen  minutes  is  a  regular  therapeutic  dose  em- 
ployed by  Pancoa-t.  Attention  is  to  be  called  to  the  fact  that  he  no 
longer  makes  the  application  to  the  spleen,  not  at  the  start,  at  all 
event-. 

The  author'*  technic  is.  to  make  a  separate  application  to  each  glan- 
dular ma--  and  to  each  knee  and  elbow  and  to  the  spleen  from  in  front 
and  from  the  side.  One  application  is  0-inch  spark.  3  ma.,  five  minutes 
unfiltered.  or  ten  minute-  through  ?>  nun.  aluminum  at  a  distance  of  10 
inches,  expo-ing  an  area  .">  inches  in  diameter.  One  application  is 
made  to  different  area-  three  time- a  week  and  in  the  first  course  of  two 
or  three  week-  each  area  has  received  one  dose.  Then  either  immedi- 
ately or  after  a  two  or  three  week-'  intermission  a  series  of  half  doses 
i-  applied  in  exactly  the  same  way. 

The  .-tandard  ( 'oolidge  tube  and  a  transformer  are  excellent  for  this 
work.  Thi-  tube  can  be  run  with  the  solid  tungsten  anticathode  in- 
eande-cent  if  the  '/,  nia.  i-  not  exceeded. 

Rontgenization  of  the  Long  Bones  Instead  of  the  Spleen  in 
Leukemia.-  This  i.-  a  method  adopted  by  Pancoasl1  in  the  effort  to 
find  ;i  tin  an-  of  permanent  cure  instead  ol  temporarv  benefit,  and  it  is  a 
method  which  seems  to  be  less  likely  to  be  accompanied  by  distressing 
accident.-  than  •  he  older  met  hod. 

:  J.mr.  Amor.  M<-<1.  Assnr.,  April  2.",,  19(is. 


RONTGENOTHERAPY  1207 

The  same  daily  applications  are  required,  and  the  same  quality 
and  intensity  of  radiation,  and  the  same  distance  and  duration  of 
exposure.  The  spleen  is  not  exposed,  and  should  be  protected  by  x-ray 
metal  if  an  x-ray  tube  is  used  without  a  localize!1.  His  method  is  to 
make  daily  exposures  of  both  knees,  for  instance,  for  three  days,  which 
usually  causes  a  reduction  in  the  number  of  leukocytes,  a  fourth  ex- 
posure being  sometimes  required.  The  different  parts  of  the  skeleton 
receive  successive  courses  of  exposure,  even  the  dorsal  vertebra  being 
treated.  After  making  a  complete  round  in  this  way,  the  same  process 
is  repeated,  and  it  may  be  that  several  rounds  will  have  been  gone 
through  before  any  applications  are  made  to  the  spleen. 

The  result  is  a  progressive  reduction  in  the  number  of  leukocytes 
and  a  return  to  the  normal  differential  count.  The  spleen  does  not 
show  nearly  as  rapid  a  change  as  when  it  receives  direct  applications, 
but,  none  the  less,  it  gradually  diminishes  in  size.  Exactly  when  to 
begin  x-raying  the  spleen  is  a  matter  of  judgment  in  individual  cases. 

The  guiding  principle  seems  to  be  that  the  spleen  should  not  be 
x-rayed  as  long  as  it  is  practically  a  great  mass  of  degenerate  leuko- 
cytes, ready  to  break  down  under  the  x-ray,  and  cause  toxemia  from 
overloading  the  excretory  functions.  The  theory  assumes  that  the 
spleen  does  not  produce  these  degenerate  leukocytes,  and  that  treatment 
of  the  spleen  merely  destroys  them  without  reaching  the  cause  of  their 
abundance.  The  application  to  the  marrow  of  the  long  bones  is  sup- 
posed to  exert  a  curative  influence  upon  the  cause  of  the  disease. 

The  results  of  this  plan  of  treatment  are  excellent. 

The  applications  should  be  made  with  very  great  regularity,  and  no 
ordinary  excuse  should  be  accepted  for  taking  a  vacation  of  even  as  long 
as  ten  days  at  any  time  until  the  blood-count  is  normal. 

Benzol  as  a  Medicine  for  Leukemia. — Koranyi  of  Budapest  was 
the  first  to  report  upon  the  benefit  to  be  derived  from  the  internal  use  of 
this  drug,  and  this  fact  has  been  verified  by  numerous  other  observers. 
A  good  mode  of  administration,  suggested  by  Kiralyfi,  is  by  capsules 
containing  7  grains  of  pure  benzol  and  an  equal  quantity  of  olive  oil. 
Two  to  ten  capsules  are  taken  after  meals  and  the  maximum  dose  is 
75  grains  (5  grammes)  of  benzol  per  day.  The  treatment  is  especially 
effective  in  cases  previously  treated  by  the  Kontgen  ray.  The  effect  is 
chiefly  that  of  reducing  the  number  of  leukocytes.  Benzol  is  a  drug  to 
be  used  cautiously,  and  not  for  an  indefinite  period  of  time.  Too  great 
an  effect  causes  severe  or  even  fatal  gastro-intestinal  irritation. 

The  Gauss  Method  of  Rontgenotherapy  for  Uterine  Fibromyomata. 
—The  use  of  hard  rays  filtered  through  o  mm.  of  aluminum,  with  the 
tube  rather  close  to  the  skin  and  the  cross-tire  principle  to  avoid  re- 
peated exposure  of  the  same  cutaneous  surface,  has  led  to  greatly  im- 
proved results  by  Kronig  and  Gauss  in  the  Freiburg  Clinic.  They  re- 
gard practically  every  case  of  myoma  as  curable  in  five  weeks,  but  con- 
sider operation  preferable  if  enucleation  is  possible  without  causing 
sterility,  or  if  there  is  probably  cancerous  degeneration  or  gangrene  or 
if  the  bladder  is  incarcerated.1 

Their  technic1'  involves  the  use  of  a  water-cooled  tube  with  a  5-inch 
principal  bulb,  connected  with  a  7-inch  accessory  bulb,  which  increases 
the  stabilitv  of  the  vacuum.  Thev  use  a  secondary  current  of  5  or  10 


1208 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


milliumperes  sent  through  the  lube  in  a  succession  of  flashes  by  a  rhyth- 
ineur.  The  tube  is  enclosed  in  a  cup-shaped  shield  of  lead  glass,  the 
orifice  of  which  is  covered  by  a  screen  of  aluminum  3  mm.  (or  -J  inch) 
thick.  The  .r-ray  is  applied  to  thirty  or  forty  different  areas  of  the  ab- 
domen, front  and  back.  Kach  area  is  about  1  inch  in  diameter,  and  upon 
it  is  laid  a  Kienbock  strip  of  photographic  paper  to  test  the  dose  applied. 
The  skin  immediately  around  this  area  is  protected  by  a  thick  lead  disk 
with  a  hole  1  inch  in  diameter,  and  overlapping  the  edges  of  this  are  two 
L-shaped  pieces  of  sheet  lead,  J,-inch  thick,  protecting  a  region  of  1  foot 
square.  Overlapping  the  lead  is  a  protection  of  .T-ray-proof  fabric  cover- 
ing the  entire  trunk  and  head.  They  place  the  tube  very  near  the  skin 
to  bring  the  anticathode  as  near  as  possible  to  the  deep  lesion,  relying 
upon  the  thick  aluminum  filter  to  stop  the  rays  which  would  chiefly 
affect  the  skin:  and  also  upon  the  fact  thai  the  dose  applied  to  the  deep- 
seated  lesion  is  divided  among  many  different  skin  areas.  Nevertheless, 
as  measured  by  the  photographic  strip  in  contact  with  the  skin,  the  dose 


iii.  M-'l.  —  Water-c 


tungsten  target  tul>r  for  (  lauss  I  rent  incut  work  (Baker  A'-ray  (  'o.). 


applied  by  these  operators  at  each  spot  appears  to  be  several  times  the 
ervthema  dose  as  measured  by  the  Kienbock  sensitized  paper.  The 
reason  this  large  dose  does  not  produce  a  dermatitis  in  each  place  to 
which  it  is  applied  is  because  the  thick  aluminum  filler  has  stopped  all 
the  ravs  which  would  be  entirely  arrested  by  the  skin  and  permits  the 
pas<ane  of  rays  which  are  approximately  homogeneous.  While  they  are 
arre-ted  in  part  bv  every  portion  of  substance  through  which  .r-ray 
pas.-es.  -till  there  is  no  great  part  which  slops  right  at  the  surface  and 
exert  ~  all  it-  effect  t  here. 

Kxperiment  s  with  a  Kienbfx  k  st  rip  placed  upon  the  surface,  and  an- 
other in  -ide  t  he  ut  ei'u  s  (after  dilat  at  ion  ),  have  shown  i  hat  one-quarter  of 
t  he  .r-ra1  •  pa  —  mii  t  hroii.Lih  '•>  nun.  ol  aluminum  readies  t  he  cavity  of  t  he 
uterus  a  n<  I  one-hall  when  1  inn:,  are  used. 

I  In1  .'  ra\  converges  upon  the  uterus  and  ovaries  from  many  dif- 
ferent port  ion-  of  t  he  surface.  Kronig  and  (  lauss  give  a  complete  t  reat- 
ment  at  a  -mule  -r--  ion.  la  st  mu  'perhaps  three  hours  and  requiring  per- 
hap-  -e\i  n  dilieivnt  .r-rav  lube-.  This  is  repeated  every  three  weeks 


RONTGENOTHERAPY  1 209 

until  permanent  amenorrhea  is  produced,  and  in  300  cases  or  more  they 
have  secured  a  complete  cure.  The  cases  in  which  amenorrhea  is  not 
secured  are  apt  to  have  a  return  of  the  fibromyorna.  (!.  K.  1'fahler  and 
John  A.  MKilinn,1  however,  consider  the  effect  upon  the  ovaries  un- 
necessary and  report  a  couple  of  cures  by  the  .r-ray  treatment  of  the 
uterus  alone. 

This  method  of  very  heavy  dosage,  even  with  filtered  rays,  is  not  to  be 
rushed  into  without  gradual,  careful  testing  of  the  effects  of  such  appli- 
cations. Necrosis  of  the  intestine  lias  been  reported  in  rare  instances  and 
also  dermatitis. 

Kronig  and  (iauss  apply  mesothorium  and  radium  internally  in  many 
cases. 

The  method  described  marks  a  very  great  advance  in  Rontgeno- 
therapy, but  requires  great  study  and  experience. 

The  author's  tcchnic  is  to  divide  the  portion  of  the.  abdomen  below 
the  umbilicus  into  four  sections  and  the  sacral  region  into  two  lateral 
halves.  For  each  application  one  of  these  areas  is  exposed  and  the  sur- 
roundings protected  by  sheet  lead  4  mm.  thick.  Kays  of  (5-inch  spark, 
70  kv.,  3  mm.,  five  minutes  unfiltered  or  ten  minutes  through  3  mm. 
aluminum  at  a  distance  of  10  inches  are  applied  to  three  separate  areas 
one  day  and  to  the  other  three  two  days  later.  This  is  a  complete 
treatment  which  may  have  to  be  repeated  two  or  three  times  a  year. 
It  may  be  combined  with  intra-uterine  applications  of  radium. 

EPITHELIOMA 

The  form  in  which  the  skin  is  not  adherent  or  fixed  to  the  underlying 
tissues  is  almost  certain  to  be  cured  by  .r-ray  treatment.  This  form  is 
frequently  met  with  near  the  inner  angle  of  the  orbit,  and  is  microscopic- 
all}'  the  same  as  the  intractable  form  occurring  on  the  lip.  The  first 
form  may  exist  for  years  without  amounting  to  very  much  locally  and 
without  glandular  involvement,  and  may  be  radically  cured  by  caustics, 
excision,  or  the  .r-ray.  The  second  form  is  clinically  an  entirely  different 
disease.  After  reaching  a  certain  stage  it  involves  the  tissues  deeply, 
produce?  glandular  metastases,  has  a  tendency  to  destroy  life,  and  is 
seldom  completely  cured  by  caustics,  excision,  or  the  .r-ray.  The  first 
type  occurs  upon  a  dry  cutaneous  surface,  the  second  usually  at  the 
nmcocutaneous  junction  at  one  of  the  orifices  of  the  body.  The  first 
may  be  called  cancroid,  as  distinguished  from  the  true  cancer  of  the 
second  type.  In  the  first  type,  or  skin-cancers,  .r-ray  treatment  is 
practically  certain  of  success  and  gives  a  better  cosmetic  effect  than  any 
ot  her  kind  of  t  reat  ment. 

Recurrence  after  surgical  excision  of  an  epithelioma  of  the  face1  is 
frequentlv  due  to  the  fact  that  the  surgeon  has  not  gone  beyond  the  in- 
fected urea,  being  influenced  by  a  desire  for  a  cosmetic  effect  and  to 
leave  as  lit  lie  deformitv  as  possible,  ('uretage,  the  galvanocautery, 
elect  rolvsis.  or  mercurial  cataphoresis  also  are  liable  to  leave  infected 
t  issue  for  the  same  reason.  The  tissues  which  are  no i  actually  destroyed 
are  sources  of  trouble  unless,  the  process  has  been  applied  beyond  the 
infected  area,  and  this  it  is  often  impossible  to  do  without  leaving 
undue  deformity.  The  .r-ray  i-  noi  open  to  any  such  objection.  It  can 
be  applied  to  a  wule  enough  area  to  include  all  the  infected  tissue  and 
some  of  the  surrounding  sound  tissue  in  a  case  of  epithelioma  of  the  face, 
and  in  a  strength  suitable  to  the  cure  of  epithelioma  it  does  not  de-troy 
1  Aincr.  Jour.  (>l>-trt.  :tnd  Pis.  <>f  Wi.nicn  and  Children,  vol.  Ixxvii,  No.  '2.  1'JIT. 


1210  MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 

neighboring  sound  tissue.  It  is  an  ideal  method  from  a  cosmetic  stand- 
point, and  for  the  reason  above  stated  a  case  of  epithelioma  of  the  face 
cured  by  the  .r-ray  is  much  less  liable  to  recur  than  one  treated  by  the 
other  methods  mentioned. 

Some  caustics,  like  pyrogallic  acid,  have  the  property  of  destroying 
exposed  epitheliomatous  tissue  without  injuring  the  neighboring 
sound  skin  and  arc  excellent  from  a  cosmetic  point  of  view.  There  is  no 
such  deformity  as  results  from  surgical  excision,  but  there  is  not  the 
same  freedom  from  recurrence,  which  is  the  chief  advantage  of  :r-ray 
treatment. 

According  to  Robinson,  the  .r-ray  as  an  exclusive  treatment  is  most 
likely  to  be  successful  in  the  variety  of  cutaneous  epithelioma  known 
as  rodent  ulcer  and  in  some  cases  of  superficial  prickle-celled  epithelioma. 
He  also  regards  certain  cases  of  rodent  ulcer,  especially  those  of  the 
crateriform  variety,  as  incurable  by  the  .r-ray  or  any  other  known 
means.  ''  Hard,  firm,  elevated  epithelial  margins  must  be  made  more 
vulnerable  by  injuring  agents,  such  as  caustics,  before  the  .r-ray  is 
applied." 

These  are  the  cases  in  which,  if  the  .r-ray  alone  is  depended  upon, 
a  more  severe  reaction  than  usual  must  be  produced. 

The  high-frequency  spark  from  a  metal  electrode  is  an  excellent  ap- 
plication for  epitheliomata  which  do  not  yield  readily  to  .r-ray  treat- 
ment, or  which,  from  their  very  appearance',  we  know  will  probably  not 
do  so.  It  has  been  referred  to  elsewhere  as  an  adequate  exclusive  treat- 
ment for  non-malignant  keratoscs  and  for  epitheliomata  where  the  dis- 
ease is  entirely  localized.  It  does  not  destroy  the  disease  beyond  the 
point  of  application  and  necrosis  and,  therefore,  in  certain  cases  it  would 
not  prevent  recurrence  unless  the  .r-ray  were  also  used. 

Microscopic  Changes  in  Cancer  Under  ,>r-Ray  Treatment. — 
Stewart1  examined  tissues  from  an  epithelioma  of  the  wrist  of  traumatic 
origin.  The  important  changes  found  were  fatty  degeneration  and 
vasculari/ation  of  the  epithelial  pearls;  leukocytic  infiltration  and  carious 
degenerative  processes  leading  to  destruction  of  tissue;  bodies  indis- 
tinguishable from  Plimmer's  bodies  multiplying  as  the  epithelia  de- 
generated. 

The  histologic  changes  in  a  case  of  epithelioma  of  the  gum  and  hard 
palate  treated  by  myself  were  chiefly  those  of  leukocytic  infiltration. 
The  disease  was  not  cured  in  this  case,  however,  only  held  in  check. 

Pusey  has  found  that  an  effect  is  produced  upon  the  morbid  epithelial 
cells  themselves,  and  consists  in  a  primary  stimulation  followed  by  de- 
generation, absorption,  and  disappearance,  and  their  replacement  by 
connective  tissue  derived  from  the  healthy  stroma.  Endarteritis  is 
produced  in  the  smaller  vessels  in  immediate  relation  with  the  tumor. 

Effect  of  Alcoholism.-  Alcohol  used  in  excess  is  injurious  in  cases 
of  epithelioma,  especially  in  elderly  persons,  and  interferes  with  the 
ellic-icv  i  if  ./--ra  v  t  real  nient .  ~ 

Application  of  a  Caustic  Before  .r-Ray  Treatment  of  Epithelioma. 
-  A  saturated  solution  of  chlorid  of  /'me  is  an  excellent  caustic  for 
removing  part  of  a  growth  or  for  rendering  an  indurated  growth  more 
susceptible  to  .r-ray  treatment .  It  forms  a  dry  eschar,  but,  has  no  selective 
act  inn  upon  t  he  diseased  tissues,  such  as  that  exerted  by  pyrogallic  acid. 

rlical  .Iniininl,  Dec.  L".t,  I'.XIti. 


RONTGENOTHERAPY 


1211 


A  desirable  technir  is  a  single  "massive"  of  3-inch  spark,  0  ma., 
five  minutes  with  l;  mm.  inch  aluminum  at  a  distance  of  10  inches. 

Flat  Surface  Forms  of  Epithelioma. — A  case  of  this  kind  was  suc- 
cessfully treated  by  the  author  at  St.  Bartholomew's  Clinic.  There 
was  an  ulcerated  surface,  looking  like  the  sluggish  raw  surface  some- 
times left  by  a  burn,  over  the  trapezius  muscle  on  one  side  of  the  neck. 
The  patient  was  a  man  sixty  years  old,  and  this  had  begun  as  a  small 
pustule  and  had  gradually  extended  until  it  measured  1  inch  by  2  inches. 
Applications  were  made  by  a  (Ireen  and  Bauer  heavy  anode  rr-ray  tube 
G  inches  in  diameter,  enclosed  in  a  Friedlander  shield  and  excited  by  an 
8-inch  induction-coil  with  a  Caldwell  interrupter  and  a  primary  current 
of  4  amperes.  The  rays  were  of  penetration  Xo.  6  Walter.  Exposures 
of  two  minutes  three  times  a  week,  at  a  distance  of  9  inches,  were  made 


Fit:.  S23. — Euitholicnia  of  forehead  cured 


?2.  —  Epithelioma    of    forehead    and 
sc  before  Rontgon  ray  treatment. 


until  a  slight  reaction  occurred,  and  were  then  reduced  in  frequency. 
It  took  about  seven  months  to  effect  a  cuiv  in  this  case. 

The  case  shown  in  Fig.  82 i  was  peculiar.  Following  a  scratch 
received  when  the  patient  was  a  girl  twelve  years  old  an  indurated  and 
ulcerated  spot  had  persisted  for  fourteen  years.  This  disappeared  under 
.r-ray  applications  made  with  the  tube  in  a  locali/ing  shield  (Fig.  S2t>), 
with  the  face  further  protected  by  sheet  lead,  through  which  a  hole  was 
cut  considerably  larger  than  the  lesion.  A  piece  of  adhesive  plaster 
fastened  the  lead  to  the  skin  around  the  lesion,  the  latter  being  left  en- 
t  irely  exposed. 

During  I  lit1  course  of  a  couple  of  years  there  were  recurrences  and 
repeated  .r-ray  treatment  and.  finally,  surgical  excision,  rnfortunately 
there  was  no  microscopic  examination.  There  has  been  no  recurrence. 

Epithelioma  Near  the  Ala  of  the  Nose. — The  following  was  such  a 


1212 


MKIMCAL    KLKl'THU'ITV    AND    KONTCKN     KAYS 


case,  the  patient   being  a  lady  sixty-seven  years  old.  whoso  father  had 
suffered  from  a  similar  trouble,  resulting  in  the  loss  of  the  entire  a!a  of  the 


nose.     Hers  began  three  years  ago  as  a  small  abrasion  and  growth  under 
the  right  eye  and  which  gradually  reached  the  condition  present  when 


t   the  n  lea  t   of  an  a  linond 


RONTGENOTHERAPY 


1213 


r  isz.  si.' (j.  —  I  cch n ir  of  Roiitjii'iiotherapv  for  enit  helioma  of  face.     Tube  in  a  locali/ii 


hit-Ill;    perforated    sheet    of   .r-rav    metal    securelv    fa-teued    to    the    surface    \>\-    adliesi 


Kpit  h>  liotna  of  nipple  which  had  fe-i^ted  radium  t  n 'at  me  tit.      Aliandoned  .r-r  i\ 


a  < Ice])  ulcer.       The  LiTi)\vth  was  freely  movable  and  t  here  \va>  IK  >  pain,  hut 


tnerelv  an  itcliinsj  and  uncoinfortank1  sensati.m.       [here  wa>  a  swcllin": 


1214 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


and  redness  of  the  malar  region.  There  were  no  glandular  involvements 
or  affection  of  the  general  health.  The  only  treatment  was  by  four 
applications  of  the  .r-ray  each  week  from  October  1.  11)04,  to  March  1, 
1  !»(>.">.  For  most  of  the  applications  a  Morton  treatment  tube  was 
used,  which  is  made  of  lead-glass  perfectly  transparent  to  light,  but 
opaque  to  the  .r-ray — this  is  the  kind  known  as  flint  glass,  and  is  the 
"paste''  of  which  imitation  diamonds  are  made.  A  piece  of  ordinary 
glass  ^transparent  to  the  .r-ray)  forms  the  end  of  the  prolongation 
through  which  the  .r-ray  passes  from  the  anticathode.  When  properly 
excited  this  tube  is  filled  with  a  beautiful  blue  light,  brighter  in  front 
than  behind  the  equator  formed  by  the  plane  of  the  anticathode.  The 


—  Fpithcliiitiia    near  lulu-  of  cur.      Had   boon   unsiircpssfully  treated  1>y  radium 


and  abandoned  .r-rav  t  rent  incut  after  three  applications. 


ry  "crown"  or  soda  ijass  forming  the  end  of  the  prolongation 

:  :•  -'.MI-  the  familiar  greenish  fluorescence  of  the  .r-ray  lube.  With  the 
>scope  ;t  >harply  deiineil  circle  of  liu'ht  is  produced  by  the  .r-ray 
from  thi-  prolongation.  It  i-  covered  with  thin  rubber  and  held  directly 
in  contact  with  t  he  part  to  he  t  rented.  A  liquid  interrupter  of  either  the 
<  -  in  type  or  the  \\'elmelt  was  used  with  a  12-inch  coil,  with 

lai'ife  M-if-ii  .  iction  m  the  primary  coil,  and  a  prunarv  current  oi  41 
amperes,  the  iv.-i.-t  atice  of  the  tube  beinc:  '_'  inches  and  the  radiometer 
(Tousey's)  '_'.  To  avoid  overheating  the  tube  it  was  applied  for  a  num- 
ber ot  ,-hort  exposure>,  aggregating  from  three  to  five  minutes  at  each 
session.  The  tubi  was  ln-ld  in  iiosition  bv  hainl.  The  last  month's 


RONTGENOTHERAPY 


1215 


treatment  was  with  a  Miiller  heavy  anode  tube,  No.  13,  and  a  local- 
izing shield  with  a  hard-rubber  prolongation,  the  end  of  which  (cov- 
ered with  thin  rubber)  was  im- 
mediately in  contact  with  the  face. 
The  anticathode  was  thus  at  a 
distance  of  10  inches  from  the 
part  to  be  treated.  The  resist- 
ance' in  the1  tube  was  2  or  3  inches, 
the  radiometer  3  or  4,  and  t In- 
duration of  exposure  six  minutes, 
with  the1  same  primary  current  that 
was  use'd  with  the  Morton  treat- 
ment tube. 

Whenever  a  certain  reaction, 
indicated  by  moderate  redness  and 
some  itching,  was  established,  the 
treatments  we're1  made  somewhat 
weaker.  The-  ulceration  was  com- 
pletely  heale-d  in  two  months  and 
a  half,  but  the1  induration  was 
more1  persistent  and  the  treatment 
was  not  completed  until  the  first 
of  March,  l!)()o.  At  that  time  the  ' 
surface1  was  flat  and  fle'xible;  there  Fi--  R20-~  Epithelioma  of  nose,  cured  by 

,  ,         ,,  jr-rav  treatment. 

was  some  redness    as    a    result  ot 

the  treatment      Three  years  after  the  cessation  of  treatment  there  had 

been  no  recurrence. 

Several  hundred  similar  cases  have  been  treated  in  different  parts  of 

the1  world  and  with  great  suc- 
cess. 

A  Case  of  Epithelioma  of 
the  Gums  and  Hard  Palate.— 
The  patient  shown  in  Fig.  s3() 
had  been  see'n  by  Dr.  Brewer, 
who  had  re-moved  a  section  for 
microscopic  examination,  and 
who  consiele'red  the1  case1  as 
unsuitable  for  operation.  She 
was  se'venty-five  years  old  and 
had  a  jxisitive1  family  his- 
tory of  cancer.  The  trouble1 
started  four  ye'ars  before1  in 
e'onsequence  of  irritation  from 
a  set  of  artificial  teeth.  When 
first  treateel.  August  14.  1!H)4, 
the  upper  gums  and  ro.if  of  the' 
mouth  and  the'  inside  of  the 
chee-k  presented  the  apjx-ar- 
ance  of  a  bright  purple-  mul- 
berry. Kach  little  nodule- was 
shiny  and  translucent.  There1 
was  comparatively  little  pain. 
The  treatment  consiste-d  in  applications  from  a  heavv  tanret  (iunde- 


1216 


MEDICAL    ELECTRICITY    AND    RONTGEN    RAYS 


Inch  tube  in  a  localizing  shield  with  a  cylinder  I1,  inches  in  diameter; 
the  distance  from  the  anticathode  to  the  diseased  surface  being  from 
*!  to  11  inches.  An  S-inch  induction-coil  was  used  with  a  Caldwell 
interrupter  and  a  primary  current  of  4  amperes.  The  resistance  of  the 
tube  was  equal  to  a  2i-ineh  spark-gap  and  the  rays  were  No.  5  Benoist. 
Kaeh  part  of  the  diseased  tissue  received  an  exposure  of  from  fifty  sec- 
onds to  two  minutes  at  each  treatment,  twice  a  week. 

There  was  more  pain  after  the  treatment  was  begun  than  there  had 
been  before,  but  this  disappeared  as  the  case  progressed. 

A  pathologic  examination,  made  October  C>,  1904,  after  two  months' 
treatment,  showed  the  same  general  type  of  epit  helioma  as  in  June,  two 
months  before  treatment  was  begun,  but  more  epithelial  pearls  and  a 
mild  acute  inflammation,  the  whole  tissue  being  infiltrated  with  pus-cells. 

Six  months'  treatment  kept  the 
growth  absolutely  in  check,  but  did 
not  cause  any  part  of  it  to  disap- 
pear. made  the  patient  more  com- 
fortable and  better  able  to  take 
all  kinds  of  food  except  those  re- 
quiring mastication.  She  had 
gained  21  pounds  in  weight.  She 
became  discouraged  bv  the  expense 
of  the  treatment  and  of  coming  to 
the  city  from  her  country  home, 
and  thought  perhaps  that  she  would 
get  along  equally  well  without  anv 
further  r-ray  treat  ment.  Reports 
during  the  ensuing  year  were  to  the 
effect  t  hat  her  niout  li  had  got  I  en 
into  terrible  condition,  and  she  died 
many  months  alter  the  ./'-ray  treat- 
ment was  stopped. 

Cancer  of  the  Lip.  This  is  a 
type  of  epit  helioma  which  is  very 
different  from  that  occurring  upon 
ot  her  part  s  of  i  he  face;  .r'-ray  t  real  - 
ment  should  not  be  depended 
upon  as  the  sole  method  of  treat- 


t  re;  1  1  men)   a  \<  me. 

Epithelioma    of    the    Eyelid    and  at  the   Inner  Canthus.     Another 

class  lit'  c;ises  i-  shown  in  Fig.  SMI,  a  seventy-five-year-old  patient  at  St. 

Bart  holon  lew's  (  'lin  ic.  with  a  deep!  v  nice  rat  ing  epit  helioma  of  the  lower 

•lid:  r-rav  treatment   \vas  emploved  for   a    period  of  about  a  Year  and 

.  but    it   did  not   succeed  in  healing  the  ulceration.         In  fact,  this 

.  '.    became  uTadiiallv  larger  during  the  course  ot  treatment.      Had 

en   in  a  region  where  more  vigorous  treatment   was  permissible  a 

cure  would  probablv  have  been  effected,  although  the  patient's  age  and 

surroundings  were  unfavorable. 

\nnt  her  unfavorable  chiss  of  cases  was  illustrated  by  a  St.  Bartholo- 
mew',- patiejil    \\nli  an  ulceration  on  the  side  of  the  nose  near  the  inner 


RONTGENOTHERAPY  1217 

canthus.  The  surface  \vus  smooth  and  red  and  level  with  the  surround- 
ing skin.  It  was  adherent  to  the  underlying  tissues  and  there  was  evi- 
dence of  deep-seated  involvement;  .r-ray  treatment  continued  for 
about  a  year  seemed  to  hold  this  in  check,  but  did  not  result  in  a  cure. 
Here  again  the  pat  lent  was  old  and  poor,  and  the  region  was  one  in  which 
vigorous  treatment  was  contraindicated. 

In  cases  like  the  two  last  .r-ray  treatment  is  useful  as  a  palliative 
means  if  an  operation  is  impracticable,  and  also  before  and  after  opera- 
tion as  a  means  of  preventing  recurrence. 

It  is  going  to  an  extreme  to  say  that  .r-ray  treatment  is  not  indicated 
in  epithelioma  where  the  skin  has  become  adherent,  but  it  is  certainly 
true  that  there  is  a  very  much  greater  prospect  of  success  where  this  is 
not  the  case. 

Cancer  of  the  Penis. — According  to  Robinson,1  the  rr-ray  has  bene- 
fited or  even  cured  certain  cases,  but  in  other  cases  he  says  it  has  has- 
tened the  growth,  and  its  long-continued  use  for  a  course  of  twenty, 
thirty,  forty,  or  even  a  greater  number  of  treatments  wastes  time  and 
may  reduce  the  possibility  of  success  from  an  operation. 

There  is  no  doubt  that  most  cases  of  cancel-  of  the  penis  should  be 
promptly  operated  upon  surgically.  The  .r-ray  used  afterward  and  com- 
menced oven  before  cicatrization  will  greatly  increase  the  patient's 
chance  of  escaping  from  recurrence.  If,  for  any  reason,  it  is  desired  to 
avoid  an  operation  and  try  the  .r-ray  as  the  sole  treatment,  the  attempt 
should  be  given  up  if  there  is  no  evident  improvement  in  three  or  four 
weeks'  time.  The  testicles  should  be  protected  by  sheet  lead,  and  in 
most  cases  the  entire  penis  and  both  groins  should  be  exposed. 

RADIOTHERAPY  WITH  THE  TUBE  IN  DIRECT  CONTACT  WITH  THE 

BODY 

The  theory  that  the  x-ray  itself  does  not  cause  radiodermatitis, 
but  that  the  latter  is  due  to  a  condenser  effect,  and  may  be  avoided 
by  placing  the  tube  in  contact  with  the  surface,  has  found  its  principal 
adherent  in  Dr.  (loysor.  His  records  show  a  series  of  about  ;">()()()  appli- 
cations with  the  tube  in  contact  without  a  burn,  but  in  a  personal  state- 
ment to  the  author  Dr.  (Joyser  says  that  he  has  had  more  than  one  burn 
due  to  the  patient  not  holding  the  tube  in  perfect  contact  with  the  sur- 
face. His  patients  have  sometimes  made  this  mistake  in  order  to  lessen 
tin-  feeling  of  static  electric  discharge  winch  they  experience,  especially 
when  the  vacuum  of  the  tube  is  a  little  higher  than  usual. 

It  should  be  noted,  however,  that  those  applications  were  with  a  small 
special  t  ube,  t  he  Cornell  t  ube  (see  p.  12  lit  i,  and  that  t  IK'  doses  were  small, 
and  that  there  seem  to  have  boon  no  comparative  experiments  with  the 
same  doses  to  prove  t  hat  t  hov  would  have  produced  irrif  at  ion  if  the  tube 
had  been  at  a  distance.  It  is  a  fact  also  that  Dr.  (!eysor  does  not 
apply  larii'o  ./'-ray  tubes  to  the  surface,  either  for  treatment  (as  in  cases 
of  leukemia)  or  for  radiography,  and  that  ho  does  not  produce  burns. 
The  same  is  true  of  other  operators.  For  instance,  in  the  author's 
service  at  St.  Bartholomew's  Clinic  not  a  single  burn  has  boon  produced 
from  the  discovery  of  the  .r-ray  to  the  publication  of  this  book,  and 
the  tube  has  been  at  a  distance  from  the  surface  in  most  cases.  The 
condenser  theory  supposes  also  thai  with  the  tube  at  a  certain  distance 

1  Xi-\v  York  .Mod.  Jour.,  JVr.  2U,  1<)()<>. 


12 


MKDICAI.    KLKi  THICITY    AND    RONTGEN     HAY; 


fn>m  the  surface  there  is  hnnuiiiity  from  burns,  but  1his  again  is  to  be 
viewed  in  the  light  (if  cases  of  leukemia,  in  which  treatment  begun  by 
1  )r.  ( ieyser  has  been  con  t  in  tied  at  the  same  distance  bv  other  operators, 
advi.-ed  by  Inn;,  and  hum.-  ha\'e  been  produced. 

1  lie  au'hor  feels  niai  the  condense]'  tlieor\'  of  the  origin  of  .r-rav 
dermatitis  has  not  been  proved,  but  that  it  probablv  contains  a  certain 
element  of  truth.  He  believes  it  exceedingly  dangerous  to  say  that  a 
burn  cannot  be  produced  with  the  tube  in  contact  or  with  the  tube  at 
a  certain  distance  ("far  enough  to  avoid  condenser  effect";,  lie  be- 
lieves that  correct  dosage  is  just  as  important  in  this  as  in  any  other 
application  of  the  ./'-rav.  He  hope.-,  however,  that  tins  method  may 
prove  a  means  of  applying  correct  doses  without  the  irritation  which 
the-'-  have  sometimes  pioduced  when  applied  from  a  distance. 

TECHXIC   OF  DIRECT  APPLICATIONS 

The  tube  is  of  lead-glass,  except  at  a  window  of  soda-glass,  where  it  is 
to  be  hel'  1  again-t  t  lie  surface. 

Different  tubes  have  been  constructed  for  this  purpose,  begin- 
nim:  with  Cossar's  and  followed  by  Morton's.  Pif'fard's,  Caldwell/s, 
Tou>oy's,  and.  mo.-l  recently,  the  Cornell  tube.  Most  of  these  can  be  ap- 


!   l>:i<-k   fnnn   tho  plane 


1 '.-  '  ;  •          :  •  ce  of  the  .-kin  or  introduced  inlo  i  he  cavities  or  held 
cc.     Then   ihei'e  should  be  mentioned  the  dii'i'erent   uni- 
Tesla's    tube  to   Stern's,    all   of  \\hich   are   intended 
i  ion. 

•'    •    :    .      •        choice   lies  between    Toil-ey's   lube  and   the  Cornell 
,  by  1  he  same  manufacl  ui'ers  u]»on  t  he 

•  •          i-ii  ion-,  \\-iiich  (he  aul  hot1  '  hinks  de- 

•    •  .*•  Rfiy   Treatment  Tube  '!';-.    '-•''.>-        The  bulb  i-  of 

prol          t  ion, 

.  -•.     The  atiod'    and  cathode  ]  "!|1-  are 

' 

; 

i 

•.    .,  I  •  I'tM     dis- 

.    i  i hat 


RONTGENOTHERAPY 


121!) 


Ilic  Tou-ey  ; ube  has  a  bull)  1  inches  in  diameter  and  ;i  h";ivv  antlcathode. 
These  features  lit  it  for  .-landing  hca\'\'  currents  for  a  sufficient  lime 
for  any  ordinary  radiograph,  where  as  small  an  area  of  illumination  as 
tins  will  cover  is  sutlicient.  Jt  holds  it-  decree  of  vacuum  better  than 
the  lighter  Conicl!  tube.  \\'hen  employing  the  Tousey  tube  one  is  not 
confined  to  lomr,  weak  applications,  of  five,  six,  or  more  minutes,  but  may 
make  an  a]) plication  of  t  he  same  amount  of  a  ray  in  one  or  t  \vo  minutes 
or  le-s  if  desired.  'This  tube  may,  therefore,  be  run  with  a  Caldwell  in- 
terrupter and  other  interrupters,  with  which  we  .-hall  sec  the  Cornell 
tube  becomes  overheated  and  loses  its  vacuum. 

Dosage  With  the  Tousey  Treatment  Tube  in  Contact  with  the 
Surface  of  the  Body. — The  anticaihode  is  only  2]  inches  or  ]()  cm. 
from  the  surface,  and  so,  when  the  tube  i-  directly  in  contact  with  the 
surface,  the  measurement  of  dosage  by  the  Sarbouraud  and  Xoire  tablets 
becomes  a  little  different  from  the  usual  method.  Ordinarilv  the  test 


tablet  is  placed  half  as  far  from  the  anticathode  as  the  surf  a  PC  to  be 

treated,  and  on   the   principle   of  the  square  of   the  distance  the  skin 

is  exposed   to  an  intensity  four  times  less  than   the  test  tablet.     \Vith 

oniact  treatment  tube,  however,  the  test   tabl-t   and  the  skin  are 

at    ihe  sain     distance  and  receive  the  same  imet:-ny  of  radiance.     A 

•  MI  ex  po- lire  to  produce  i  in  i  /•'  in  \  '•:-  >:  '  ••••:":•.''.'  I  and   Xoire  radi- 

•    ..        '  •  '  ir  .,'.•>—•!•,    \    .  out  Al  II.  if  ti      -kin  i-  i '/.•ice  as  far 

:  ;n  icrii  hod,;-.  Inn     •  '  :'   : !  •    co-'/a--;    •  ent  the  same 

"•;  : lie  (-1  >]or  of  the  i       •      I  •  he  dose  del 


1220  MEDICAL    ELECTRICITY    AND    KONTGEN    HAYS 

the  soda-glass  window,  glass  prolongations  insulating  the  electrodes, 

the  turning  of  the  latter  away  from  the  patient,  and  the  insulated  glass 
handle.  The  differences  are  lighter  construction,  contributing  to  easy 
handling,  hut  detracting  from  ability  to  stand  the  current. 

Dr.  deyser's  originality  lies  in  the  routine  use  of  the  tube  for  contact 
treatments,  with  the  claim  that  the  same  amount  of  .r-ray  will  not  pro- 
duce a  burn  in  this  way,  as  if  the  tube  were  at  some  distance  and  a 
condenser  effect  were  thereby  established. 

There1  are  certain  technical  details  which  must  be  observed  in  the 
use  of  the  Cornell  tube.  These  are  consequent  upon  the  small  si/e  of 
the  bulb  and  the  lightness  of  the  anticathode.  Currents  of  the  strength 
ordinarily  employed  in  radiography  or  radiotherapy  almost  imme- 
diately cause  the  tube  to  break  down.  The  anticathode  becomes  over- 
heated and  the  vacuum  falls  below  the  useful  limit.  There  are  several 
way.-  in  which  this  can  be  prevented  and  the  tube  kept  in  working  order 
long  enough  for  the  therapeutic  effect.  If  the  \Yehnelt  interrupter  is 
used,  it  is  found  desirable  to  expose  a  very  great  deal  of  the  platinum 
point,  so  that  a  heavy  current  of  lo  amperes  will  be  allowed  to  flow, 
but  with  very  slow  interruptions.  The  rheostat  ma}'  be  used  in  securing 
this  effect.  Kach  of  the  slowly  repeated  impulses  produces  a  flash  of 
.r-ray,  and  an  application  of  about  live  minutes  is  required  when  the  tube 
is  excited  in  this  way.  Another  method,  which  will  usually  be  found 
preferable,  is  to  use  a  mechanical  interrupter,  such  as  the  "Wappler 
interrupter,  adjusted  to  give  quite  slow  interruptions  and  a  current  of 
about  2  amperes.  About  five  minutes'  application  is  desirable  in  this 
case,  but  the  quantity  of  .r-ray  bears  such  a  direct  relation  to  the  number 
of  interruptions  per  minute  that  even  a  very  slight  difference  in  the  ad- 
justment of  the  interrupter  will  necessitate  a  decided  change  in  the 
durat  ion  of  the  exposure. 

Any  technic  is  suitable  which  enables  the  proper  quantity  of  x- 
radiation  to  be  applied  without  overheating  the  tube. 

CARCINOMA 

The  cases  in  which  .r-ray  treatment  may  produce  a  cure  are  prac- 
tically limited  10  those  of  the  breast  and  other  external  parts  with- 
out internal  glandular  involvement,  and  the  more  nearly  the  tumor 

roaches  in  microscopic  structure  the  border-line  between  a  ma- 
lignant and  a  benign  growth,  the  greater  is  the  prospect  of  complete 

Effect  of  rr-Ray  Treatment  in  Cancer. — The  mode  of  action  of  the 

./"-ray  in   the  treatment    of  cancer  has  been  studied  by   J.yle.1      lie  has 

ahvays  noted  an   abundant    discharge  after  the  applications,  and  this 

rtre    is    alkaline    and    crystalli/es   when    exposed    to   the   air.      lie 

-  this  as  an  external  evidence'  of  a  cln-mic  effect,  which  accounts 

he    toxemic    symptoms    v.hidi    sometimes    follow    an    application. 

il'-  thinks  that   1l:is  cliemic  product   is  dangerous  and  sometimes  fatal, 

!  .r-rav  treatment  should  be  limited  to  cases  in  which  drainage 

can  be  <  -'ablished.  and  that   it   should  not   be  used  in  deep-seated  caii- 

ccrs, 

Apropo-  of  t]  is,  the  present  author  believes  thai  substance's  analo- 
gous; to  toxin-  or  antitoxins  are  produced  by  exposure  of  a  cancer  to  the 

1  Me-liral   Hfvonl,  Julv  1."),   1(10.1. 


RONTGENOTHERAPY  1221 

.r-rny;  that  the  production  and  absorption  of  those  substances  in  large 
doses  causes  toxoinic  symptoms;  but  that  in  proper  proportions  they 
have  a  curative  effect  upon  cancel1.  1  have  many  times  seen  a  beneficial 
effect  upon  cancerous  involvements  which  from  their  position  (as  to 
depth  or  otherwise)  could  not  have  received  enough  radiation  to  produce 
a  direct  effect.  It  is  true  enough  that  a  cancer  which  forms  a  flat,  open, 
and  freely  discharging  ulcer  may  properly  receive  larger  doses  of  the 
x-ray  than  a  malignant  tumor  without  ulceration. 

Perthes1  has  noted  that  the  cancerous  cells  fuse  into  a  uniform  pro- 
toplasmic mass  with  an  irregular  outline  and  that  their  nuclei  stain 
less  and  less  well.  Leukocytes  and  connective-tissue  cells  penetrate 
the  mass;  later  the  cancer  cells  are  seen  imprisoned  and  isolated  in 
the  meshes  of  connective  tissue  and  undergo  degeneration  and  absorp- 
tion. 

Ellis2  thinks  that  the  .r-ray  produces  necrosis  of  both  the  parenchyma 
and  the  stroma  of  the  tumor,  accompanied  by  proliferation  of  elastic 
tissue  and  obliterative  endarteritis. 

According  to  Schwartz,  the  .r-ray  causes  a  decomposition  of  the 
lecithin,  which  is  more  abundant  in  rapidly  growing  cells,  like  those  of 
neoplasms  and  like  the  normal  parenchymatous  cells  of  the  testis.  and  in 
this  way  has  a  destructive  effect  upon  these  particular  cells  in  doses 
which  do  not  affect  other  healthy  tissue  cells. 

Mouse  tumors  taken  out,  x-rayed,  and  put  back,  grew.  When 
the  mouse  was  x-rayed  after  the  tumor  was  taken  out  and  then  put 
back  it  did  not  grow.  The  theory  is  that  the  x-ray  caused  lymphocytosis 
which  inhibited  the  growth  of  the  tumor,  but  further  radiation  would 
lessen  this  inhibition.3 

The  fact  that  serum  from  a  part  which  has  been  strongly  x-rayed 
may  produce  symptoms  of  an  x-ray  dermatitis  if  injected  into  a  part 
of  the  same  or  another  animal  which  has  not  been  irradiated  is  sug- 
gestive of  a  cliemic  effect.  It  may  be  that  an  anticancerous  serum 
could  be  injected  deeply  into  the  substance  of  a  malignant  tumor  and 
produce  a  greater  degree  of  benefit  in  the  depths  than  the  rays  weak- 
ened by  absorption  in  passing  through  the  superficial  parts  of  the 
tumor.  This  could  be  done  without  exposing  the  patient  himself  to 
the  x-ray. 

From  the  diversity  of  opinion  among  the  above  and  many  other 
authors  it  is  evident  that  we  do  not  know  the  exact  way  in  which  the 
x-ray  affects  the  cancer  cells,  whether  by  a  direct  action  or  by  an  electro- 
lytic process.  There  seems  to  be  no  doubt,  however,  that  cancer  cells 
have  an  especial  susceptibility,  and  that  under  favorable  circumstances 
they  may  undergo  degeneration  and  absorption  without  ulceration  or 
destruction  of  the  mass  of  tissue  making  up  the  tumor. 

( 'ases  of  cancer  have  died  suddenly  quite  a  long  time  after  having 
been  treated  with  a  great  deal  of  benefit  by  the  x-ray."1 

'Thirty—croud  ('on<ir<'>s  of  the  (icnnaii  Siiruiral  Society,  Berlin,  June  li. 
r.  to: ; 

-  Ainrr.  .lour.  Mod.  Sciences,  Jmmary.  P.'<i:5. 

3  Murphy.  Ainer.  Jour.  Klertrother.-ipv  :,nd  Radiology,  vol.  xxxvi,  Xo.  :i.  March, 
I'.tls,  p.  [ST. 

1  Hu>enl>erii«T.  Second  IIoiii-cu  (  'onure-s.  I'.'ii.",. 


1222 


CARCINOMA   OF   THE   BREAST 

The  technic  employed  I >y  1  he  author  is  (i-incli  .-park.  ~.\  ma.,  filter 
of  '.\  nun.  aluininuin,  distance  10  inches,  ten  minutes  to  each  area,  re- 
peated every  three  or  four  weeks. 

The  absorption  by  the  tissues  is  such  that  of  a  surface  dose  at  X 
inches  from  the  ant  icat  hode  and  with  .r-rays  corresponding  to  a  9- 
inch  spark  gap.  only  one-seventh  reaches  4  inches  below  the  surface.1 
Bo^s'  standard  dose  is  20  x  Koenig  (( iauss  modified  Kienbock 
scale),  and  this  is  produced  in  a  Coolidge  tube,  a  modern  transformer, 
S-inch  distance,  4  mm.  aluminum  filter.  9-inch  resistance,  25  ma. 
minutes. 

For  a  cancer  of  the  breast  with,  of  course,  possible  involvement  of  the 
mediastinal.  axillary,  and  supraclavicular  glands  as  well  as  other  neigh- 
boring structures,  Boggs  applies  such  a  dose  to  each  of  the  following 
areas:  (1)  Three  or  four  areas  of  the  anterior  chest  wall  and  extending 
toward  the  axilla  and  liver ;  ( 2 )  the  three  or  four  areas  of  axilla  and  one  area 
of  the  side  below  the  axilla;  (3)  three  or  four  supraclavicular  areas; 
(4j  supra-  and  subscapula;  (o)  one  or  two  to  mediastinum  from  behind, 


Fie.  S.'j4. — Recurrent  carcinoma  of  the  male  brea.  t  cured  (no  recurrence  in  five  years)  by 

ar-r;iv  treatment . 


between  the  opposite  scapula  and  the  spine;  ((>;  four  to  eight  areas  of  the 
opposite;  (7)  epigastric.  A  second  course  is  given  four  weeks  later. 
While  each  of  these  many  areas  is  receiving  the  .r-ray,  all  other  parts 
are  protected.  There  is  a  cross-fire  effect. 

In   a   ureat    many   cases  of  recurrent    cancer  of    the   breast    there   is 

contraction   of  the  axillary  cicatrix  which   binds  the  arm  more  or  less 

to  the  -ide  and  make-  it   difficult   to  apply  the  .r-ray  to  the  axilla.      It 

ha-  been  succe-sfully  accomplished  hv  the  present   author.     The  .r-ray 

•i  liplicd  from  in  Front  while  1  he  ell >ow  is  drawn  back  as  far  as  possible ; 

and    fV'im    behind   while   the  elbow   i-  drawn   forward  across  the  chest. 

way  every  part  of  t  he  axilla  is  either  exposed  direct  ly  or  through 

thi'-k   obstruction   of  fle-h   in   cases   where   the  elbow  cannot    be 

d   ironi  the  -ide  more  than  a  few  inches. 

.  of  course,  i-  very   <-onvenient  ly   applied   even    in    the   most 
ext  -    df  axillary   contraction   and   ulceralive   neoplasm. 

nf  a  case  of  carcinoma  of  the  ma  le  breast  referred  to  t  he 


author  bv  IV.  K.  \Y.  Hall.  I  operated  upon  the  original  growth  in  one 
breast,  removing  a  tumor  which  the  pathologic  examination  showed 
to  l»e  carcinoma,  but  with  an  appearance  which  did  not  indicate  the 
great  est  degree  of  malignancy.  There  was  recurrence  in  t  he  ot  he!1  breast 
within  a  year  and  .r-rav  treatment  was  at  once  begun.  Mild  applica- 
tions were  made  three  times  a  week  until  the  development  of  a  mild 
erythema,  and  then  the  treatment  was  kept  up  sufficiently  to  keep  the 
skin  slightly  reddened.  The  tumor  made  no  further  headway  from  the 
time  that  the  .r-rav  was  first  employed,  but  there  was  no  perceptible 
diminution  in  the  size  of  the  tumor  for  about  nine  months.  Then  it 
bewail  to  improve,  and  in  two  more  months  not  a  trace  of  it  remained. 
The  region  of  the  original  growth  was  .r-rayed  at  the  same  time  as  the 
other,  but  never  showed  anything  but  a  somewhat  suspicious  appear- 
ance. It  is  now  five  years  since  the  cessation  of  treatment  and  there 
has  been  no  return  of  the  growth. 

Figure  S35  is  of  a  patient  referred,  May  12,  1905,  by  Dr.  Clement, 
of  Cleveland.  The  patient  was  a  lady  sixty-four  years  old  upon  whom 
the  surgeon  had  five  years  previously  performed  an  amputation  of  the 
breast,  with  removal  of  the  pectoralis  major  and  the  axillary  contents. 
The  microscopic  examination  showed  that  the  disease  was  carcinoma. 
There  had  been  a  recurrence  in  about  two  years  which  was  considered 
inoperable,  and  for  which  x-ray  treatment  was  applied  for  twelve  months 


Fit:.  V!."). — Inoperable   recurrent    carcinoma   of  1>re:i-t    held    in    check    for   lliree   veurs   ti\ 


with   a   great    deal  of  benefit.      Some  tune  had   passed  since  then,   and 


asse  appearance  ot 


the  breast  and  axill  i  and  enormous  swellum'  of  the  arm.      Measur 


1224  MKDUAL    ELKITRICITY    AM)    K(")NT(IKN    RAYri 

made  at  this  time  showed  an  increase  of  2  inches  at  the  wrist,  of  3£ 
inches  in  the  forearm,  of  21  inches  at  the  elbow,  and  of  2\  inches  at  the 
arm  over  the  circumference  of  corresponding  parts  of  the  other  arm. 
A  fluoroscopic  examination  showed  that  there  was  no  intrathoracic 
tumor. 

This  case  never  showed  anything  resembling  a  toxemic  reaction  from 
the  x-ray  applications. 

An  example  of  the  technic  employed  is  found  in  the  following: 
Miiller  Xo.  13  tube,  induction-coil  110-volt  direct  circuit,  Wehnelt 
interrupter.  5  amperes  primary  and  3  ma.  secondary  current,  resistance 
21  inches,  radiometer  Xo.  (j,  exposure  five  minutes  at  a  distance  of  12 
inches  from  the  anticathode,  limited  to  an  area  8  inches  in  diameter  by 
a  localizing  shield  with  its  3-inch  diaphragm.  The  exposures  were 
sometimes  divided,  so  that  the  axilla  and  the  breast  received  exposures 
like  the  above  separately. 

High-frequency  currents  were  applied  to  the  arm,  breast,  axilla,  and 
side  of  the  neck  from  ultraviolet  ray  vacuum  electrodes. 

Treatments  were  given  three  times  a  week,  except  for  a  couple  of 
months  in  the  summer,  and  for  two  years  the  disease  was  held  in  check 
and  the  patient  was  well  and  happy  and  attending  to  her  usual  social 
duties.  The  disease  in  the  meantime  seemed  to  have  lost  its  malignancy, 
There  remained  some  fulness  of  tissue  at  the  anterior  fold  of  the  axilla, 
but  there  was  no  longer  any  ulceration,  and  the  arm  was  much  less 
swollen.  Then  came  a  period  of  gradually  increasing  pain  in  the  region 
of  the  other  shoulder-blade.  There  also  developed  a  small  abrasion  at 
the  anterior  fold  of  the  axilla  that  was  quite  painful.  The  great  swelling 
nf  the  arm  never  returned,  although  some  swelling  continued  throughout 
the  entire  course  of  the  disease.  While  no  local  appearance  of  malig- 
nancy was  apparent,  it  was  evident  that  her  general  strength  was  failing, 
and  the  patient  died  in  September,  l'.M)7.  This  was  seven  years  after 
the  operation,  and  for  the  last  five  years  of  her  life  x-ray  treatment 
had  kept  her  perfectly  comfortable  and  an  active  member  of  society  in 
spite  of  the  presence  of  an  inoperable!  carcinoma.  There  were  a  great 
many  times  when  the  patient  forgot  about  the  trouble,  and  really  the 
only  annoyance  for  months  at  a  time1  was  the  swelling  of  the  arm. 

Another  case  was  referred  by  Dr.  Hissell.  The  patient  was  about 
fortv  years  old.  and  had  been  operated  upon  two  years  previously  for 
a  carcinoma  of  the  breast,  which  she  had  concealed  until  it  was  too  late 
to  hope  for  anything  like  a  cure.  The  poor  lady  also  concealed  the 
fact  of  a  recurrence  in  the  other  breast  until  it  formed  a  larire  ad- 
herent  mass  and  her  general  condition  precluded  operative  treatment. 
'1  here  was  also  recurrence  in  the  cicatrix  on  the  side  which  had  been 
operated  on.  1  he  pat  lent  had  a  verv  si  ran  lie  v  a  so  neurosis,  which  at  the 

'    in-pection  <>f   the  case   and  before   the   x-ray  was   turned  on  caused 
hest    to   become  a  fierv  red   like   the   most   violent    blushing, 
kepi   her  face   covered  with  a  thick  veil,  so  that 
'!'  the  deep  blu-h  suffused  the  face   also.       At    .- 
h  lira  dually  became  less  marked  over  1  he  chest,  and  finally, 
••  i|  lite  accustomed  to  ihe  presence  of  the  oper- 
.   :'    ceased  to  occur.      At    a    subsequent    period,  however. 
•  :  '    -uriieoi  .    v  r  'i   was    consulted    in    regard    to    a    conipll- 
•    rei  ini    of   thi-   vivid    blu-h    covering   the   entire 
;'    the  x-rav  had  been  u-'-d  the  natural   supposition 


RONTGENOTHERAPY 


1225 


was  that  the  redness  he  saw  was  the  first  symptom  of  x-ray  dermatitis; 

and  from  its  extent   and  vividness  the  doctor  thought   that   there,  was 

going   to   bo  a  severe  burn.     Tin's 

appearance, 

tive. 

The    treatments    in 
were  of  the  same  kind 


>f  course,  was  decep- 


this    case 
as  in  the 
case1   previously   described.      The 

first  treatment  was  followed  by  a 
febrile  movement,  102°  F.,  with 
some  prostration.  This  was  at- 
tributed to  a  temporary  toxemia 
caused  by  the  x-ray  exposure. 
It  did  not  occur  again  during  the 
course1  of  treatment. 

This  patient  did  wonderfully 
well  for  a  time,  the  recurrent 
tumor  in  the  breast  diminishing 
one-half  in  size  and  the  original 
cicatrix  assuming  a  natural  ap- 
pearance. The  patient's  general 
health  was  greatly  improved. 
Then  came  a  complicating  pleu- 
risy, with  effusion,  and  a  rapid 
illness,  which  terminated  fatally. 
It  cannot  be  doubted  that  death 
was  due  to  cancer,  but  the  treat- 
ment gave  wonderful  benefit  for  a 
time  in  a  desperate  case.  It  looked  at  one  time  as  if  the  disease 
might  even  be  arrested  for  years,  as  in  the  case  previously  described. 

X  "  T 


1,.,-k    fur  tv.,,  ;,,.,!   ;,     ;alf  vears  1, 


-ra\    treatment.      (   a-c  alter  !\vn  yeai>    t  r<  atn.i  M 


hoconsulled  the  author  about  what  she 


•  iirure  S.'-U)  i-  (it    a   n; 


regarded  as  an  un  healed  burn  t'r<  >m  ./'-fay  I  rea  H  i  icn  t  s  bv  another  opera  to] 


MKDlt    \L    F.l.Kl  TRKITY     AM)     UO.NTi.KN     HAYS 


s.-is.- -  Inoperable  carcinoma  of  breast  held  in  chock  for  two  and  a  half  years  bv  Ront- 
genotherapy.     Case  a  few  weeks  before  death. 


f   bn'.'isl   \\il'i   ftinnnou>   edema  of  the 


122' 


more  than  two  years  previously.  These  lesions  are  extremely  painful 
and  very  slow  to  heal,  though  in  the  case  referred  to  the  carcinoma  itself 
seemed  to  have  been  checked  by  the  treatment.  Jchthyol  ointment 
and  high-frequency  currents  applied  from  a  glass  vacuum  electrode 
give  more  relief  than  anything  else  in  such  a  case  and  also  promote 
cicat  rization. 

In  addition  to  the  carcinoma  of  the  breast,  this  patient  had  developed 
a  flat  epithelioma  of  the  other  side  of  the  face. 

The  patient's  daughter  died  of  carcinoma  of  the  breast. 

Prognosis. — Cancer  of  the  breast  which  has  been  operated  upon 
and  which  has  recurred  gives  excellent  results  at  first,  but  after  a  certain 
period  there  may  come  a  time  when  the  disease  pets  beyond  control. 
This  may  take  a  few  months  or  several  years,  as  in  some  of  the  author's 


Fin.  S-t(). — Inoperable  recurrent  carcinoma  of  breast.      Held  in  check  for  a  year  by  Ront- 

genotherapy. 

cases.  The  :r-ray  appears  to  prevent  the  development  of  external 
growths  or  uleeration,  and  keeps  the  patient  comfortable1  and  for  a  time 
strong  and  well.  The  (Mid,  when  it  does  come,  is  usually  from  internal 
involvement  and  often  without  definite  symptoms.  Scirrhous  cancer 
of  the  breast  in  old  persons  presents  a  less  unfavorable  prognosis. 

RECURRENT  CARCINOMA   OF  THE  LARYNX 

The  patient.  AV.  If.,  was  a  man  of  thirty-seven  years,  and  was  re- 
ferred to  tin1  author  in  April.  1  !•<).">.  by  Dr.  Moore,  of  Xew  Brunswick, 
X.  J.  The  first  symptoms  of  throat  trouble  developed  in  April,  1902. 
On  April  17,  1!»()1.  he  had  undergone  a  complete  excision  of  the  larynx 
for  carcinoma,  and  during  thai  year  had  been  breathing  through  the 
tracheotomy  tube.  In  February,  1'ifi.").  however,  he  became  unable  to 
swallow  ail}'  food,  either  liquid  or  solid,  in  consequence  of  the  return 


MKDICAL    KLKCTUK  ITY    AND    RONTGEN    RAYS 

of  the  growth  shutting  off  the  esophagus.  A  gastrostomy  was  per- 
formed March  15,  1!M).">,  by  ])r.  Moore,  and  at  about  the  same  time  the 
doctor  wrote  to  me,  making  inquiry  as  to  the  probability  of  benefit 
from  .r-ray  treatment  after  recovery  from  the  shock  of  the  operation. 
The  reply  was  encouraging,  and  a  few  weeks  after  the  operation  had 
been  performed  the  patient  began  making  regular  trips  to  my  office  for 
.r-ray  treatment.  When  1  first  saw  him  there  was  a  considerable  swelling 
in  the  neck,  presenting  almost  the  appearance  of  a  new  larynx,  and 
above  the  tracheotomy  opening,  in  the  median  line,  was  a  discharging 
sinus,  from  which  some  of  the  liquids,  milk.  etc..  which  he  tried  to 
swallow  escaped.  The  whole  region  was  red  and  swollen,  and  pre- 
sented the  typic  appearance  of  a  recurrence  of  carcinoma.  An  .r-ray 
picture  which  is  reproduced  herewith  (Fig.  841)  was  made,  and  shows 
the  presence  of  the  hyoid  bone  and  the  absence  of  all  the  cartilages  of 


1!        C-.i-i-    < >f    l.-irvTiircctumv    niul    bom-fit    from    .r-r:tv   trr-.'itnifiiT    for    rffiirrciil 


.:-::. Lr   '_'    -trutomv.      J.iirlit   ;irc:i    in   mini    «>    upper  verteunr:   pturnl    part    <>1 


,     i  •.   uml   t  ••; 


the  larynx,  and  demonstrates  also  very  prettily  the  obliteration  of  the 
trachea  below  the  level  of  the  hvoid  bone.  The  patient's  weight  at 
t  hi-  •  imc  wa~  10H  pounds. 

I  he  treatmeiil  consi.-led  in  the  application  once  a  week  of  the 
r-ray.  allowed  to  shine  above  the  front  and  side-  of  the  neck.  All 
oi  '  he-e  a pplicat  ions  were  <  \ternal,  and  i'ollowei  1  a  very  d is!  met  formula 

Mi*   author  has  found  -ucces.-ful  m  manv  cases  of  recurrent  malig- 

o 

t  uniors. 

The  r-r.'tv  lube  ha-  a  tuntr-ten  anticalhode  and  i-  about  7  inches 
in  diameter,  and  has  also  an  accessory  anode.  A  little  side  tube,  con- 
ned • . '_>  wii  ii  t  he  main  one,  has  means  !or  li  iweriim"  the  degree  o|  \-aciium 
li\-  -en  .  u'j  ',]  portion  <  >f  ihe  current  through  thi-  regulator.  The  anti- 
c:i '  :  -  a  m. -i  —  '  if  cop  pi  r.  \\'ei^hin^  \  pound,  with  a  but  Ion  of  t  ungsten 

-urfacc   which   faces  obliquely   toward   the 


K(")\T( ;  K\(  )TH  KHA  I' V  1  229 

cathode.  Tungsten  has  a  melting-point  twice  as  high  as  that  of  plati- 
num. With  a  moderate  strength  of  current  this  type  of  tube  maintains 
its  degree  of  vacuum  longer  than  most  other  types.  The  metal  does  not 
liberate  many  particles  of  gas  unless  it  becomes  red  hot.  At  the  dif- 
ferent treatments  the  spark  length  varied  from  2\  up  to  o  inches,  and 
for  one  or  two  treatments  even  7  inches,  while  the  degree  of  pene- 
tration varied  from  2  to  (>  or  even  8  units  of  the  Benoist  radiometer 
scale. 

The  effect  of  treatment  was  to  reestablish  the  ability  to  swallow, 
though  this  always  remained  difficult,  to  materially  increase  the  man's 
weight  and  strength,  and  to  cause  a  great  reduction  in  the  cancerous 
swelling  in  the  neck.  This  improvement  continued  for  about  a  year, 
but  did  not  save  the  man's  life. 

CANCER  OF  THE   TONGUE 

Guilleminot1  reports  4  cases  of  carcinoma  of  the  tongue  unsuccess- 
fully treated  by  the  .r-ray. 

CANCER   OF  THE   SHOULDER 

A  case  of  inoperable  cancer  of  the  shoulder  has  been  reported  as 
cured  by  .r-ray  applications.1' 

SECONDARY   CARCINOMA   OF    THE   MEDIASTINUM 

Carcinomata  of  the  mediastinum,  secondary  to  cancer  of  the  breast, 
have  been  treated  with  benefit  in  the  direction  of  relieving  symptoms 
and  prolonging  life.  Pfahler  has  published  the  histories  of  0  such 
cases. 

The  object  should  be  to  us*1  such  a  quality  of  ray  and  to  have  the 
tube  at  such  a  distance  as  will  produce  a  deep  effect  without  undue 
irritation  of  the  skin.  The  ant icathode  of  the  .r-ray  tube  should  be 
about  10  inches  from  the  surface*  and  the  penetration  should  be  about 
No.  7  Benoist,  (i-inch  resistance,  70  kv.,  '•*>  ma.,  but  the  proportion  of 
soft  rays  reduced  by  the  use*  of  a  o  mm.  aluminum  filter.  A  maximum 
exposure  would  be  ten  minutes,  equal  to  •">  II..  and  not  to  be  repeated 


be  greater  from  frequently  repeated  mild  exposures  than  from  single 
severe  ones.  A  dosage  of  \  Ilol/knecht  unit  will  usually  be  found  cor- 
rect. The  cross-fiiv  system,  whereby  the  ray-  reaching  the  growth  pass 
through  different  portion-  of  skin  each  time,  and  e.-pecially  always 
protecting  the  skin,  which  i-  not  in  a  direct  path  toward  the  growth, 
add  greatly  to  the  efficacy  of  the  treatment. 

CARCINOMA   OF   STOMACH   AND   INTESTINES 

\\  e  can  seldom  hope  tor  more  than  a  palliative  effect  in  cancer 
of  the  stomach  or  intestines,  but  even  here  tin1  treatment  give-  much 
relief  from  pain  and  adds  much  to  the  patient's  strength. 

A  case  treated  by  the  author,  in  consultation  with  l)r.  T.  M.  Lloyd. 
Allowed  temporary  relief  front  pain  and  from  almost  complete  pylorir 
obstruction.  He  became  able  to  retain  food  and  had  natural  move- 


12  MO  MKim'Al.     HI.KCTHICITV    AND    lit  >NTi ;  F.N    KAYS 

iiH'i!!-  ot  the  bowels,  lie  died.  however,  in  a  few  weeks  from  exhaus- 
tion. The  disease  \vas  of  long  -landing  and  of  such  an  extent  and  the 
patient's  condition  so  critical  that  no  operation  appeared  justifiable, 
and  the  .r-ray  and  the  ultraviolet  ray  high-frequency  applications  were 
made  with  tin'  hope  of  temporary  relief  only. 

More  recently  the  author  ha-  Treated  such  cases  at  a  somewhat 
earlier  -taue  and  with  very  great  benefit.  A  screen  of  aluminum  o  mm. 
thick  ha-  been  u-ed  and  the  anticathode  placed  at  a  distance  of  10  inches 
from  the  skin. 

A  palpable  tumor  of  tin1  right  iliac  region  in  a  patient  referred  by 
Dr.  Park',  proved  to  be  a  gelatinous  mass  which  recurred  after  opera- 
tion. Tin-  recurrence  was  also  accompanied  by  distention  of  the 
abdomen  with  the  saint1  gelatinous  substance.  .c-Hay  applications  to 
all  four  quadrants  of  the  abdomen  combined  with  radium  applications 
to  the  ri^ht  iliac  tumor  made  a  very  great  improvement  in  the  patient's 
weight  and  strength,  ability  to  take  nourishment,  and  in  the  action  of 
the  bowel-.  Combined  with  occasional  operative  removal  of  the 
gelatinous  substance,  the  treatment  has  maintained  this  improvement 
for  some  years.  The  diagnosis  is  obscure. 

CARCINOMA  OF  THE   UTERUS 

A  patient  was  rcfcrn-d  by  ])r.  Hoyle.  She  was  a  lady  fifty  years  old, 
with  a  very  large  uterine  fibroid  winch  made  her  look  as  if  in  the  last 
month  of  pregnancy.  Carcinoma  of  the  cervix  had  developed  and  she 
ndergone  a:i  operation  under  ether.  'The  whole  pelvis  was  found 
to  be  one  solid  ma-.-  of  cancer,  and  so  the  operation  \va.-  limited  to  the 
removal  of  a  section  large  enough  to  examine  microscopically.  The 
pathologist  reported  carcinoma,  and  the  probability  seemed  to  be  that 
it  could  live  bul  a  few  weeks.  Treatment  b\  the  .''-ray  was 
begun,  however,  the  patient  having  to  come  in  a  carriage,  assisted  by 
her  physician  and  her  mother,  husband,  and  nurse.  There  was  an 
:  •  nd  very  offensive  discharge  and  great  pain  over  the  ovarian 

and  lumbar  regions.      The  .r-rav  was  applied  partlv  over  the  abdomen 

II  I 

>ugli   a   vaginal  speculum.      T'ne  distance  tVom  the  anti- 

f-athodf  to  the  abdominal  wall  was    1.'!  inches  and  the  rays  were  \<>.  7 

•  •mlit   minutes.      (  Mherwise  the  details  were  the  same 

•i-  in  the  case  of  cancer  of  the  brea-1   described  on  p.    l_'_'l.      The  same 

t  !•(•':  nar  \\as  ii-  tlie  vaginal  applicat  ion-,      'i'he  .r-ray  tube  was  a 

No.   \'-\.  and   lo'-ah/al  i.  :n   wa-  accomplished  bv  covering 

i  in-  pat  lent '.-  bti:  tock-  and  t  hi^rh-  wit  h  .r-ra.y  me;  a  i  wit  h  :\  hoh-  ju-t  large 

1      •  •  i  •   j  y\'(  'si  'lit    \\  i'!  i  ing  t  he  atii  !n  *r  makes 
-imila r  ca.-e-  b\  then-eol  a  locali/ing  shield  and 

:  w  i  1 1 1   !  t . 

\  :  •  •        rom  one  pi  '••    of  the  /'-ray  coil  were  applied  over 

1  •        -     ;•  i  eal  ment .      The  t  real  - 

:  '      •  .     month.-     i  ' ;  i , '  •  ' '  1 1 ' 

:  •   .    '      • 

.   .  . 

•     •  •:  '  '  :        \  ;':••!• 

• 


RONTGENOTHERAPY  1231 

ably  from  cancer,  but  without  any  of  the  pathognomonic  symptoms  of 
that  disease. 

Other  cases  t  reated  by  the  author  and  other  operators  show  that  it  is 
not  unusual  to  have  marked  improvement  as  to  hemorrhage,  discharge, 
pain,  odor,  and  general  strength.  It  is  practicable  even  to  carry  such 
a  patient  through  pregnancy  and  to  see  a  healthy  child  horn,  but  the 
ultimate  prognosis  seems  to  he  uniformly  bad. 

General  Results  in  Carcinoma.—  The  preceding  cases  of  carci- 
noma, some  cured,  but  most  treated  with  very  great  temporary  benefit, 
but  nevertheless  dying  in  from  six  months  to  six  years,  are  fair  exam- 
ples of  what  may  be  expected  from  /-ray  treatment  of  this  disease. 

SARCOMA 

The  author's  teehnic  is  0-inch  resistance.  3  ma..  10-inch  distance, 
3  mm.  aluminum  filter,  ten  minutes  for  a  "massive"'  dose  over  each 
area,  not  to  be  repeated  inside  of  three  weeks. 

Squamous-celled  epithelioma  is  less  favorable  for  radiotherapy. 
The  best  are  tumors  with  the  largest  and  most  prominent  nuclei. 
Lymphosarcoma  recurrences  end  in  death.1 

/-Hay  or  radium  should  not  be  tised  before  operation  and  should  not 
be  neglected  after  operation.2 

Many  cases  of  this  disease  are  favorably  influenced  by  /-ray  ap- 
plications and  a  few  cases  have  perhaps  been  permanently  cured. 
There  is  no  particular  form  of  the  disease  which  is  recognised  by  all 
observers  as  especially  apt  to  be  favorably  influenced,  and  in  no  form 
is  this  treatment  cont  raindicnted.  The  general  principle  is  the  same 
as  in  the  "radiotherapy  of  other  malignant  disease-—  the  .r-ray  has  a 
depressant  effect  upon  ever\*  kind  of  tissue.  The  rapidly  proliferating 
cells  of  neoplasms,  like  the  normal  cells  of  the  testis  and  the  ovary,  are 
more  susceptible  to  ihe  influence  of  the  .r-rav  than  other  ceils.  The 
/-ray  is  applied  in  doses  from  which  the  more  susceptible  tissue-cells 
cannot  recover,  but  from  which  the  neighboring  sound  tissue-cells 
do  recover  after  a  period  of  depression.  V\  here  small  repeated  doses  are 
employed  ihe  quantity  applied  is  such  that  the-  sound  cells  completely 
recover  from  the  effect  of  one  application  before  the  next  one  is  made, 
while  the  neoplastic  cells,  more  decidedly  affected,  do  not  completely 
recover  between  applications  and  experience  a  cumulative  eitect.  Ihe 
operator  arranges  the  strength  and  frequency  of  the  applications  with 
t  his  end  in  view. 

Ilolzknecht  regards  sarcoma  as  more  easily  influenced  than  epitheli- 
oma hv  the  .r-rav.  Colev,  who  is  not  a,  radiologist .  but  who  has  had  a 
large  number  of  cases  treated  In*  the  /-ray.  helieve<  thai  the  mixed 
toxins  o|  ervsipelas  and  M reptocnccns  an  o!  urea!  value  in  sarcoma. 
According  to  his  conclusions,  ihe  antitoxic  ;  realm  -n!,  either  alone  or 

Mos     •  :t.  ;:< :!o'ji-:  •=,  on  t  he  oi  hi  r  hand.  ,         '  :      ;  hue  or  i        •  "i- 

IM  ci  ion  \\  f'  i!  -ui'irical  nn  asup  -  :-:  :  ;  ••  :       ••  «:'  .-    '•••••••. 

momen'    after  ihe  diam 


MH1MCAL    KLl-XTHUTTY    AND    KOXTCEN    RAYS 


be  removed  with  a  reasonable  degree  of  completeness  without  danger  to 
life  and  without  too  great  mutilation. 

The  .r-ray  has  been  employed  as  a  prophylactic  before  surgical  treat- 
ment. The  advantage  to  be  derived  is  somewhat  doubtful  as  com- 
pared with  the  benefit  to  be  derived  from  an  early  operation.  Still, 
if  the  case  is  not  a  threatening  one,  and  if  the  patient's  general  condition 
is  such  that  preliminary  constitutional  treatment  by  tonics  and  hygienic 
surroundings  is  required,  .r-ray  treatment  may  be  recommended  during 
this  preparatorv  treatment.  The  benefit  sought  is  to  reduce  the  size 
of  the  tumor  and  so  make  it  susceptible  of  more  complete  removal,  and 
especially  to  convert  some  of  the  lymphatic  channels  into  fibrous  cords 
ami  thus  reduce  the  liability  to  the  formation  of  metastases.  These 
preliminary  applications  should  include  a  generous  area  of  tissue  around 
the  growth,  and  the  doses  had  better  be  mild  and  frequently  repeated. 
Prophylactic  applications  after  an  operation  are  of  undoubted 
value,  and  may  be  begun  immediately  after  recovery  from  the  effect  of 
the  operation.  It  is  not  necessary  to  wait  for  the  wound  to  heal  and  the 
applications  may  be  made  through  the  dressings.  The  doses  should  be 

small  and  frequently  repeated,  and 
should  be  continued  until  about  7  H. 
have  been  applied  in  about  three; 
weeks.  Then  applications  of  1}  or 
4  II.  may  be  mad*1  every  two  weeks 
for  two  or  three  months.  'Flu1  qual- 
ity of  the  ray,  as  represented  by  its 
degree  of  penetration,  depends  upon 
the  depth  at  which  the  lesion  is  lo- 
cated. No.  ">  to  7  Benoist,  .l-inch 
resistance,  is  correct  for  the  treat- 
ment of  the  cicatrix  after  an  am- 
putation of  the  breast,  while  rays 
No.  0  or  10,  (i-inch  resistance,  would 
be  suitable  for  a  case  of  sarcoma  of 
the  kidney.  The  use  of  a  screen  for 
soft  rays  is  to  be  recommended  in 
almost  every  case.  The  rays  which 
I  hose  which  would  be  absorbed  by  the  skin,  and  by 
we  are  enabled  to  make  more  effective  applications 


TREATMENT   OF   AN   INOPERABLE   PRIMARY   OR    RECURRENT   SARCOMA 

\\liat  i-  said  under  I  he  head  of  Melanosarcoma  and  in  the  earlier 
paragraphs  on  Sarcoma  give<  the  author's  view>  as  to  prognosis.  The 
treatment  i-  a  little  different,  however,  in  the  direction  of  being  more 
-i  vere.  It  should  be  as  thorough  as  possible  without  causing  ulcer- 
alion.  Kit  her  the  method  ol  large  doses  of  about  7  II.,  repealed  everv 
I  \\'o  or  three  weeks,  or  that  of  smaller  doses.  1  or  2  II.,  everv  two 
or  three  days,  may  be  applied.  The  same  differences  between  deep  and 
-iiperficinl  lesions  call  for  differences  in  the  degree  of  penetration  and 
also  IMF  dillerences  in  the  distance  from  the  anticathode  to  the  surface 
of  the  [tody.  The  latter  distance  may  be  as  small  as  desired  when  the 
disea-e  i-  practically  on  the  surface  of  the  body,  but  the  distance  from 
the  ant  icat  hode  to  t  he  -iirface  of  t  he  bodv  must  be  about  II)  inches  when 


K<">XT<  ;  K.\<  >TI  i  KKA  i' v  1 233 

the  disease  is  deeply  located.  This  is  on  account  of  the  fact  that  the 
intensity  of  the  radiance  diminishes  as  the  square  of  the  distance  in- 
creases. The  distance  from  the  anticathode  to  the  skin  should,  there- 
fore, he  a  large  fraction  of  the  distance  from  the  anticathode  to  the  dis- 
ease, so  as  to  make  less  relative  difference  between  the  two  distances 
and  less  difference  between  the  intensity  at  the  two  places.  \Yith  the 
tube  close  to  the  surface  the  intensity  at  the  skin  may  be  four  or  six 
times  as  great  there  as  at  a  deep-seated  growth,  and  hence  it  would  be 
impossible  to  produce  sufficient  effect  upon  a  deep-seated  growth  with- 
out destroying  the  skin.  This  is  without  taking  into  account  the  fact 
that  the  deeper  tissues  receive  a  reduced  strength  of  application  in  con- 
sequence of  absorption  by  the  superficial  tissues.  A  localizer.  such  as 
the  Ripperger  shield,  with  a  4-inch  diaphragm  should  be  generally  used 
to  limit  the  action  of  the  rays  to  the  region  of  the  disease. 

rlopatt1  reports  the  case  of  a  woman,  with  probably  malignant 
lyinphosareoma  of  the  anterior  mediastinum,  successfully  treated  bv 
lifty  applications  of  the  .r-ray.  Radiographs  showed  a  reduction  and 
finally  the  complete  disappearance  of  the  unnatural  shadow  cast  by  the 
growth,  and  there  was  a  coincident  disappearance  of  tin-  dyspnea  and 
other  symptoms.  It  is  not  known  whether  the  growth  recurred. 

Helot  and  Bissene-'  have  treated  cases  of  diffuse  sarcoma  of  the  skin 
and  of  premycosis  and  mycosis  fungoides  by  the  .r-ray.  The  last- 
named  disease,  although  due  to  a  germ  infection,  has  many  of  the  prop- 
erties of  cutaneous  sarcoma,  and  the  .r-ray  in  massive  doses  of  o  to  7 
Holzknecht  units  of  rays  No.  I  or  ">  Benoist  has  effected  a  cure  in  the 
two  or  three  cases  in  which  it  has  been  used.  Scholt/  uses  even  larger 
doses,  intending  to  produce  superficial  necrosis,  but  this  does  not  seem 
necessary.  In  the  cases  treated  by  Belot  it  happened  that  one  or  two 
small  regions  accidentally  received  a  larger  dose  than  7  H.,  and  the  effect 
was  less  desirable  than  elsewhere. 

A  case  of  very  malignant  sarcoma,  involving  the  soft  tissues  at  the 
angle  of  the  jaw.  recurring  after  t  wo  opera t ions,  disappeared  under  .r-ray 
treatment  and  had  not  returned  a  year  later.3 

Xo  doubt  exists  in  the  author's  mind  of  the  occasional  permanent 
curability  of  sarcoma,  both  of  the  bones  and  soft  parts,  by  Rontgen  ray 
treatment.  This  is  also  the  experience  of  Skinner  of  New  Haven.,  Piah- 
ler  of  Philadelphia,  and  M.  L.  Dorn  among  others  abroad. 

MELANOSARCOMA 

This  disease  usually  responds  favorably  to  .r-ray  treatment,  and 
shows  either  an  arrest  of  the  morbid  process  or  an  almost  complete 
disappearance  of  the  visible  lesions.  Some  cases  which  have  been  re- 
pi  >rt e<  1  showe<  1  onl v  a  very  t empoi  a rv  arrest .  but  in  most  case.-  tin'  benefit 
was  long  continued.  The  ultimate  result,  it  i-  to  be  feared,  will  be  that 
the  majontv  of  eases  cannot  'he  permanently  held  in  check.  .Mild. 
frequently  repeated  doses,  without  ever  exciting  an  inflammatory 
reaction,  have  given  good  results  m  some  cases,  while  a  case  treated 
bv  Bisserie,  an  ulcerated  inelanosarcoma  of  the  nipple  with  axillary 
adenopathy,  received  an  application  of  !)  11.  ot  ray.-  Xo.  -t  or  .">.  re- 
peated fifteen  days  later.  There  was  an  intense  reaction,  followed  by 


12:}  l 


MKDH'AL    ELECTRICITY    AND    KOXTCEX    KAYrS 


complete  healing  ;>f  the  ulcer,  and  three  months  later  there  remained 
only  a  small  non-ulcerated  and  painless  tumor  of  the  consistence  of  a 
lipoma. 

The  milder  method  is  generally  more  suitable  for  non-ulcerated  sar- 


I'iir.  ^43.  — Molanosarcoma  of  back,  recurrent.      Only  one  or  two  rr-ray  treatments;  with- 
out much  effect. 

comata  and  the  severe  applications  for  the  uleerated  and  more  threat- 
ening cases. 

As  in  other  cases  of  malignant  disease,  the  application  should  gen- 
erally l>e  limited  to  the  region 
immediately  embracing  the  dis- 
ease. Some  constitutional  effect 
is  doubtless  always  produced  by 
breaking  down  of  malignant  tis- 
sue under  the  influence  of  the 
.r-ray.  and  the  author  believes 
that  in  many  cases  an  antitoxic 
action  is  thus  secured.  Kxten- 
sions  ot  disease  in  regions  not 
exposed  to  the  .r-ray  or  in  conse- 
quence of  their  deep  location  re- 
ceiving only  a  small  fract  ion  of  the 
dose  applied  to  surface  lesions  of  ton 
receive  marked  benefit .  which  1  he 
author  Accounts  tor  on  the  hy- 
pothesis given  above.  (  'ases  may 
occur  in  which  the  same  profound 
effect  on  the  Mood  from  which  so 
much  benefit  occurs  in  leukemia 
mav  be  sought  in  sarcoma.  It 
may  1  ie  o!  it  ained  !  iy  applicat  ions 
over  1  he  spleen  and  I  he  long  bones. 
The  c;i<e  o|  melanosarcoma  of 
the  back  and  urom  sliown  in  1'  la's. 
S  1!!  and  S  I  1  was  referred  to  i  lie 
tapid  recurrence,  bolli  locallv  and  in  the 


HOXT<  i  K\<  >T!I  K.UA  I'Y  1  235 

those  did  not  produce  any  perceptible  e-hange  in  the  course  of  the  dis- 
ease. The  case  is  introduced  niorolv  for  the  purpose  of  describing  the 
author's  technic.  The  .r-ray  tube  was  a.  Mi'iller  No.  13  heavy  anti- 
eatlKtde1  tube  (>  inches  in  diameter.  It  was  enclosed  in  a  Hippor^or 
shield  or  wooden  box  lined  with  lead  oxid.  At  a  distance  of  (>.',  inches 
from  the  antic'lthode  there  was  an  opening  (i  inches  in  diameter,  which 
was  (lin%cted  toward  the  part  to  be  treated.  The  patient  lay  face  down 
on  the  table,  with  the  anticat hode  of  the  tube  13  inches  from  1  he  surface 
of  the  back;  an  area  S  inches  in  diameter  was,  therefore,  exposed  to  the 
.r-ray.  A  12-inch  induction-coil  was  used  with  the  110-voll  direct  cur- 
rent and  a  Wehnelt  interrupter,  transmitting  fi  amperes  of  primary  cur- 
rent and  sending  1  ma.  of  secondary  current  through  the  .r-ray  tube. 
The  rays  were  No.  0  Benoist,  4-inch  resistance.  Kach  exposure  lasted 
three  minutes,  and  was  equivalent  to  1  Ilol/knecht  unit.  These  ap- 
plications were  to  have  been  made  three  times  a  week  until  a  slight 
cutaneous  reaction  was  established,  and  then  reduced  in  strength  or 
frequency  so  as  to  maintain  a  slight  reaction. 

A  case  of  recurrent  alveolar  melanotic  sarcoma,  of  the  neck  seemed 
to  be  entirely  cured  by  three1  months'  .r-ray  treatment  a.pplied  after  the 
second  operation.  The  wound  had  failed  to  heal  and  the  growth  was 
rapidly  extending  to  the  entire  neck.1 

MULTIPLE  PIGMENTED  SARCOMA 

The  .r-ray  affords  some  benefit  in  this  fatal  disease  and  is  the  only 
treatment  that  does  so.  The  difference  between  this  and  melanosarcoma 
is  in  the  arrangement  of  the  cells  and  also  in  the  fact  that  the  pigment 
in  melanosarcoma  is  largely  melanin,  and  in  this  disease1  it  is  mostly 
hemosiderin.  It  usually  first  develops  on  the  hands  or  fee't  and  extends 
upward  to  involve  vital  organs.2 

Stcoutliirji  x-Itai/s  from  Silver  hi  the  Alimentary  CaftaZ.— Hernaman 
and  Johnson3  have  found  that  there  is  a  elefinite  value  to  the1  secondary 
x-radiation  fre>m  metallic  silver  in  the  alimentary  canal  for  the'  treatment 
of  malignant  disease  thereof. 

FLUORESCENT  MEDICINES   IN  CONNECTION  WITH  X-RAY  THERAPY 

Experiments  by  the  author  show  that  the  various  fluorescent  media 
which  have  been  given  internally  while*  the  patient  was  exposed  to 
the  .r-ray  probably  have1  no  beneficial  result,  due  to  the  luminosity 
e-xcited.  Some  of  them,  like  bisulphate  of  ejuinin.  are  excellent  tonics 
in  themselves,  and  this  is  not  questioned  at  all,  but  the  .-pecial  claim 
ha>  been  made  that  these  substances,  circulating  in  the  blood  and  in 
all  t  lie  other  tissues  of  the  body,  become  fluore'scent  under  the  influence 
of  the  .r-ray  and  generate  light  in  the  tissues  and  that  this  light  has  a 
beneficial  effect  upon  cancerous  tissues.  The  tact  that  so  good  a  man 
as  \Ym.  J.  Morton  advocates  this  method  is  sufficient  to  make  it  worthy 
of  the  mi  isl  careful  considerat  ion. 

The  fhioresconl  medium  recommended  by  Kemp  for  gastrodia- 
phany  is:  Ouinin  bisulphate1,  gr.  x.  in  a  glass  of  water,  to  which  i.-  aelded 
111  iv  of  dilute1  phosphoric  acid.  After  this  has  be-en  .-wallowed  a  glass 
of  plain  water  is  also  to  be  taken. 

1  Dr.  Kihvin  Walker.  Medical  Hmml.  Xov.  S,  1  <>()•_>. 
-  LirbiTthal.  N<-\v  York  Mccl,  Jour..  June  ~2:\.  I'.iiMi. 
3  Abstract,  Aincr.  Quarterly  ut"  Hui'iit^i'imlnu-y,  M:iivh.  Hirj.  p.  ."7. 


MKDK  AI.    KLKCTUIC1TV    AM)    KnNTOKN    KAYS 

I  his  uives  sufficient  fluorescence  when  an  electric  lamp  is  intro- 
duced into  the  stomach  to  produce  :i  visible  luminous  area  indicating 
the  sixe.  shape,  and  position  of  the  stomach.  The  experiment  must  be 
curried  out  in  a  dark  room. 

Fluorescin  is  more  strongly  fluorescent  and  is  non-toxic  in  the 
strength  of  i  to  }  grain  to  the  pint  (gin.  0.07  or  0.14  per  ">()()  cc.j. 

Fluorescin  produce.-  a  medium  for  gast  rodiaphany  when  prepaied  as 
follows: 

(live  the  patient  S  ox.  of  water  with  ,~j  of  glycerin,  gr.  xv  sodium 
bicarbonate,  and  gr.  J  fluor<-scin.  This  should  be  prepared  one-half 
hour  previously  and  exposed  to  sunlight. 

F.-culin  is  also  an  excellent  non-toxic  fluorescent  substance. 

Fit  her  of  the.  three  media  described  above  will  become  luminous 
when  ordinary  light  shines  through  them.  This  is  due  to  a  slowing  of 
the  rate  of  vibration  in  the  waves  of  light  in  passing  through  the  liquid, 
and  each  particle  of  liquid  becomes  in  a  certain  sense  a  source  ot  colored 
liuht  nearer  the  red  end  of  the  spectrum  than  the  light  was  originally. 
White  light,  seen  by  transmission  through  such  a  .-oh it  ion,  may  have  one 
color,  while  by  reflection  it  sometimes  lias  quite  a  different  color.  Many 
fluorescent  substances  are  dichroic  in  this  way. 

A  striking  example  of  the  slowing  effect  upon  vibrations  of  light  by 
fluorescent  substance's  is  shown  by  a  simple  experiment: 

The  spectrum  of  the  Cooper-Hewitt  mercury  vapor  lamp  is  almost  a 
pure  violet',  as  seen  in  a  spectroscope,  but  when  a  piece  ot  cloth  coated 
with  a  suitable  fluorescent  substance  is  held  close  to  the  lamp  and  the 
reflected  light  from  t  he  clot  h  is  examined,  t  wo  brilliant  red  lines  are  seen 
to  spring  into  view. 

Fluorescent  substances  become  luminous  and  variously  colored  under 
the  influence  of  the  ultraviolet  rav,  which  is  itself  of  such  rapid  vi brat  ion 
as  to  be  invisible. 

Thev  also  behave  in  t  he  same  way  under  the  influence  of  radium  ray.-, 
themselves  invisible. 

Thev  inve  the  same  phenomena  under  the  influence  of  the  ./"-ray  as 
in  the  case  of  the  barium  plat inocyanid  screen,  which  is  so  universally 
u-ed  in  fluoroscopic  examination.-. 


NATURE   OF  THE   RADIANCE  FROM   FLUORESCENT   SUBSTANCES 
'1  he  aut  hor's  belief  that   I  he  radiance  t  rom  t  hese  .-ill  ist  a  nee-  consist  s 
practicallv  entiivlv  of  ordmarv  visible  li^ht.  and  not   of   invisible  ultra- 
violet   rav-.   i-  ba-ed   partlv  upon   the  following: 

Kj-jii-riniftil  (by  the  author,  Feb.  L'V  !!)()?*»).-— .\  Machlett  .r-ray  tube, 
nivinu'  rays  No.  7  IVnoi-l.  .~>-inch  re-i-tanee  or  -park  equivalent  and  ."> 
Ilia.,  u  a-  r -ii closed  in  a  Ripperger  -hield.  wit  h  a  1-inch  diaphraum  in  a  per- 
fed  1  v  dark  room .  A  piece  ol  \\  illemite,  exposed  direct  Iv  to  the  radiance 
from  the  .r-ra  \'  !  ul  >e.  showed  the  -a  me  ^  reen  fluorescence  that  expo  -in  e  to 
!'  lolet  ray  lamp  produce-  m  it.  It  \\a-  much  le--  brilliant,  how- 
e\'er,  '  •'.',  ou  Id  have  been  m  the  latter  ca>e.  Still.  \\  illemit  e  <erves 

tl  e  pre-ence  of  r-ra.Vs.  ju-t  as  it  i-  used  as  a  te.-t  for  the  rays 
from  radium,  none  of  which  are  |  hose  lechnicallv  referred  to  as  ultra- 
\'io|et  \\illemite  fluore-ce-  -o  brilliantly  \\heii  expo-ed  to  the 

ultra'    •    •  '  thai    it-    yTeen    coloration    -er\'e~   a-   a    verv    delicate    te-t 

for  thi    pi  '         radiation.      Now  a  barium  plat  inocyanid  -creen 

wa-    placed  •       '       '    lore-ci-nt     -urface    a\\ay    from    the    ./'-rav    tube. 


1237 

The  "Willemite  fluoresced  \vitli  a  green  color  \vhcu  held  in  front  of  the 
barium  platir.ocvanid  in  a  line  with  the.  r-ray.  The  color  disappeared, 

In  >wever,  when  the  \\  illemit  e  was  licit  1  somewhat  to  one  side  of  the  open- 
ing in  the  diaphragm  so  as  to  be  shielded  from  the  ,  /'-rays,  though  near 
enouglit  to  the  brilliantly  fluorescent  barmm  plutinocyanid  screen  to 
recei\re  whatever  rays  emanated  from  the  latter.  The  result  was  a  pale, 


from  an  ultraviolet  lamp  has  to  pass  through  ordinary  glass  to  reach  it, 
and  is  in  this  way  deprived  of  the  ultraviolet  rav.  Interposing  a  piece 
of  ordinary  glass  between  the  fluorescent  screen  and  the  Willemite  did 
not  lessen  or  change  this  appearance  in  any  way. 

The  last  part  of  the  experiment  seems  to  show  that  the  radiance 
emitted  by  barium  platinocyanid  under  the  influence  of  the  .r-ray 
does  not  contain  the  .r-ray  or  any  of  the  rays  characteristic  of  radio- 
active bodies,  or  the  ultraviolet  ray  in  sufficient  amount  to  be  demon- 
strable by  so  delicate1  a  test  as  Willemite. 

A  strong  solution  of  fluorescin  (gr.  j  to  oz.  j  )  in  a  perfectly  dark 
room  fluoresces  brilliantly  when  exposed  to  the  .r-ray  from  a  tube 
entirely  enclosed  in  black  paper  (experiment  by  the  author  Feb.  29. 
1904),  so  that  no  visible  Hu'ht  could  ivach  the  solution. 

The  proper  solution  for  internal  administration  (experiment  by  the 
author  March  4,  1904)  consists  of  (1)  gr.  -J,  fluorescin  in  ~>j  alcohol, 
(-)  f>ss  glycerini.  (.'>)  f>ss  to  j  olive,  oil.  (4)  water,  q.  s.  ad.  1  pint.  Mix 
thoroughly  at  every  stage.  The  above  solut  ion  gives  only  a  questionable 
fluorescence  with  the  unshaded  .r-ray.  The  same  solution  fluoresces 
well  with  the  light  from  an  ultraviolet  ray  vacuum  electrode.  This 
solution  really  forms  a  very  delicate  test  for  ultraviolet  rays.  Since 
it  shows  onlv  a  doubtful  fluorescence  when  exposed  to  the  .r-rav.  it  is 
evident  that  no  appreciable  generation  of  ultraviolet  rays  can  take  place 

111   l!    when  so  exposei  1. 

Kven  if  the  stomach  were  filled  with  this  solution  in  a  case  of  cancer 
oi  t  hat  organ,  exposure  to  the  .r-ray  could  produce  only  trivial  luminositv 
in  the  liquid  and  probably  no  ultraviolet  rays.  When  we  consider  the 
hundred  or  more  applications  of  an  hour  each  from  an  ultraviolet  lamp 
of  KIIK)  or  more  candle-power  required  in  the  treatment  of  lupus 
or  epilhelioma.  it  seems  impossible  that  the  feeble  radiance  from  the 
liquid  in  question,  acting  for  only  a  few  minutes,  could  produce  any 
effect  upon  the  cancer.  I  'he  author  has  given  a  fluorescent  solution  of 
quin  in  m  tin-  way  m  a  case  oi  cancer  of  the  stomach  and  could  not  see  that 
it  modified  the  effect  of  the  .r-ray  in  any  way. 

Another  experiment  by  the  author  (March  12.  190  H  consisted  in  partly 
removing  the  vegetable  matter  which  filled  the  stomach  of  a  dead  rab- 
bil  and  replacing  it  with  a  radio-active  solution  and  then  making  a 
radiograph  showing  the  stomach  region.  The  .r-rav  l  ube  was  enveloped 
m  !  >l;ick  paper  and  i  he  room  was  darkened.  No  fluorescence  or  gastro- 
diaphanous  appearance  was  visible.  The  fluoroscope  showed  great 
franslucency  through  the  dilated  stomach,  and  tins  same  tact  is  shown 
in  the  radiograph.  Another  radiograph,  inade  after  the  stomach  has 
fern  emptied,  shows  a  verv  u'reat  difference.  (  >nlv  a  skilled  anaionn-t 
could  tell  where  the  stomach  i.-.  The  conclusion  from  t  his  experiment  is 
that  a  radio-active  solution  introduced  into  the  stomach  doe-  not  assist 
m  radioscopy  bv  any  transillumination  effect.  Since  the  increased 
i  u'liet  rabilit  v  was  attributed  to  the  mass  of  vegetable  matter  m  the 


MEDICAL    ELECTRICITY    AND    KONTGEN    KAYS 

stomach  it  is  not  probable  that  the  radio-activity  of  the  solution  had 
anything  to  do  with  making  the  radiograph  >how  the  stomach  more 
clearly. 

INFLUENCE     OF    THE    INJECTION    OF    PHOTODYNAMIC    SUBSTANCES    INTO 
THE    TISSUES    BEFORE    A'-RAY    EXPOSURES 

A  solution  of  eosi  n  1  :  1000  has  been  injected  into  the  tissues  by  Kothe,1 
who  has  found  that  verruca1  will  disappear  after  an  exposure  to  the  .r-ray 
too  short  to  produce  any  effect  upon  other  verruga1  which  had  not  been 
injected.  Similar  results  were  obtained  in  treating  lupus  and  in  experi- 
ments upon  rabbits. 

RADIOTHERAPY   IN   INFECTIOUS  DISEASES 
SPECIFIC  IMMUNITY 

The  development  of  toxemia  under  .r-ray  applications  hailed  to  the 
suggestion  by  A.  AY.  Crane2  that  .r-ray  applications  might  be  used  to 
generate1  an  antitoxin  in  the  system  of  a  patient  suffering  from  an  infec- 
tious disease.  This  has  not  been  sufficiently  experimented  with  to  know 
whether  it  will  prove  efficient.  Possible  advantages  are  that  the  anti- 
toxin (using  the  term  in  a  broad  rather  than  a  strictly  accurate  sense) 
liberated  is  derived  from  the  identical  germs  or  morbid  tissues  which  are 
present  in  the  patient,  and  thus  the  harm  which  might  come  from  an 
error  in  diagnosis  and  the  use  of  the  wrong  specific  antitoxin  or  serum 
by  ordinary  inoculation  is  avoided.  The  method  does  not  at  all  sup- 
pose a  direct  bactericide  action  of  the  .r-ray  upon  pathogenic  micro- 
organisms in  living  patients. 

RONTGEN  APPLICATIONS  FOR  PRODUCING   STERILITY 

Men  may  be  rendered  sterile  without  loss  of  desire  or  ability  for 
coition.  The  reported  cases  in  which  this  has  been  done  were  given 
applications  sufficient  to  produce  decided  dermatitis  without  ulceration 
of  the  scrotum.  The  spermatozoa  were  still  absent  six  months  later. 

Women  may  be  purposely  made  sterile  by  exposure  to  the  .r-ray 
applied  over  the  ovaries.  The  greater  thickness  of  tissue  to  be  pene- 
trated makes  this  require  more  total  exposure  than  is  the  case  in  men. 

A-'vnvlli  Aitilio''  reports  the  cure  of  a  case  of  osteomalacia  by  in- 
ducint:  ovarian  atrophy  through  .r-ray  applications. 

(iatiss1  regards  the  attempt  to  produce  sterility  by  the  x-ray  as 
dangerous,  and  when  he  attempts  to  produce  abortion  obtains  a  written 
promi-e  from  the  patient  to  have  an  operative  abortion  performed  if 
the  .r-ray  fails.  This  is  to  prevent  a  possible  lawsuit  for  the  birth  of  a 
•  lefi  >rmed  child. 

I).  iiN<-h.  M-'l.  Worh..  Sept.  1",.  I'.uil. 
'-  Am.  .Jnur.  <>f  .Mi'.lir;tl  Sciences,  M:uvli.   !'.»()*. 
1'  illctiriD  <iel!;i  Society  I.:i nci-i;i tin  di   Roma.   I'.Hiti. 

•>   1  l.y  A.  II;t!iiin.  Tlic-r.-tj).  Monutshcfte,  xxvii.  No.  7,  July,  1913. 


RADIUM 

KAPIUM  is  a  new  clement,  which  is  supposed  to  exist,  but  which  has 
not  yet  been  isolated.  Several  of  its  salts,  especially  the  bromid 
and  the  sulphate,  have  been  obtained  in  what  is  thought  to  be  a  pure 
slate,  and  if  is  from  the  study  of  these  that  our  knowledge  of  radium 
itself  is  derived. 

It  is  classified  as  a  metal  of  the  alkaline  earths,  very  similar  to  barium. 
Its  atomic  weight  has  been  calculated  to  lie  about  226  times  that  of 
hydrogen.  It  is  thus  one  of  the  heaviest  metals.  The  other  metals 
which  are  radio-active  also  have  very  high  atomic  weight.  The  atomic 
weight  of  polonium  is  234;  that  of  uranium  is  240;  while  that  of  bismuth, 
which  is  radio-active  from  an  admixture  of  polonium,  is  208. 

This  very  high  atomic  weight  is  thought  to  account  in  some  way 
for  the  property  of  radio-activity  possessed  by  these  substances. 

The  spectrum  of  radium  shows  twelve  distinctive  lines,  one  of  them 
in  the  ultraviolet  region  being  particularly  marked.  Pure  radium 
bromid  colors  the  flame  of  a  Bunscn  burner  carmine. 

Such  small  amounts  of  radium  salts  have  been  produced  and  they 
are  so  expensive  that  the  efforts  of  the  chemist  have  been  devoted  to  the 
means  of  obtaining  them  in  a  pure  state  rather  than  to  a  study  of  the 
various  possible  compounds  and  reactions  of  radium. 

The  bromid  is  the  most  active;  salt  of  radium,  and  occurs  in  the  form 
of  small  white  crystals,  which  are  very  soluble  in  water.  It  is  hygro- 
scopic, and  exposed  to  the  air  will  gradually  absorb  sufficient  moisture 
to  become  liquefied. 

Kadium  chlorid  has  the  same  properties,  but  is  not  so  powerfully 
radio-active. 

The  sulphate  and  the  carbonate  are  white  powders  and  are  insoluble 
in  water.  The  sulphate  is  preferable  for  almost  every  purpose1  except 
for  the  intravenous  or  subcutaneous  injection  of  a  radium  solution. 

Xone  of  these1  radium  salts  are  destroyed  or  dissipated  even  by  a 
red  heat,  although  their  radio-activity  is  some'times  temporarily  reduced. 
Kadium,  therefore,  is  less  interesting  from  a  chemic  than  from  a  phys- 
ical standpoint.  The  complex  phenomena  known  as  radio-activity  are 
what  make1  radium  inteTesting  and  valuable. 


RADIO-ACTIVITY 

Kadio-active  substances  were  discovere-d  in  IMMt.  shortly  after 
Kfmtgen's  discovery  of  the  .r-ray  in  ls!)">.  Becquerel  found  that  rays 
of  a  character  somewhat  similar  to  that  of  the  .r-ray  were  given  off  by 
the1  metal  uranium. 

Becquerel  rays  (named  from  their  discoverer),  <>r  the  rays  froir, 
uranium,  produce-  many  of  tin1  effects  of  the  .r-ray.  They  affect  a 
photographic  plate,  ionize  gases,  and  this  electrification  is  governed  by 
the  same  laws  as  in  the  case  of  the  .r-ray.  The  Becquerel  rays,  how-, 
ever,  are1  reflected,  refrae'ted,  and  polarize1*!  in  the  same  manner  as  light, 

1239 


1210  MKDICAL    KLKCTKICITY    AND    K<">XT(,KX     KAYS 

aii«l  mu.-T  have  about  the  same  wave  length.     Class  lias  the  same  index 
oi  retraction  lor  these  ra\'s  as  for  ordinary  lisiht. 

The  3"-Rays  or  Blondlot  Rays. — They  are  given  the  name  .Y-rays 
in  honor  ot  Xancv,  France,  where  Blondlot  is  a  professor.  The  >ources 
troin  which  they  are  generated  are  the  ordinarv  luminous  bodies,  in- 
cluding the  Crookes  tulie.  the  \Yelsbach  and  -imilar  lights,  the  Xernst 
lamp,  red-hot  metals,  and  the  sun;  and  also  non-luminous  bodies,  in- 
cluding bodies  in  a  state  of  stress,  sonorous  bodies,  a  magnetic  field, 
Hertzian  waves,  liquefied  liases,  odorous  substances,  soluble  ferments 
vegetable  tissues,  and  the  human  body.  Thev  ha\'e  very  similar 
properties  to  t  hose  of  ordinary  light ,  and  under  favorable  circumstances 
are  believed  to  make  the  human  body  visibly  luminous  in  an  entirelv 
dark  room.  It  is  only  fair  to  add  that  many  unprejudiced  observers 
have  found  themselves  unable  to  perceive  this  luminosity. 

Discovery  of  Radium.—  M.  and  Mme.  Curie,  of  Paris,  made  a  series 
ot  very  delicate  tests  of  the  radio-activity  of  different  specimens  of  ura- 
nium residue,  and  fotind  that  they  differed  very  markedly  in  activity. 
The  inference  was  drawn  that  some  substance  of  greater  radio-activity 
than  that  of  uranium  was  present  as  an  impurity.  This  substance, 
which,  however,  has  not  been  completely  isolated,  is  called  polonium, 
from  Poland.  Madame  Curie's  native  country. 

The  further  investigation  of  radio-activity  was  carried  on  by  the 
Curies,  the  line  of  investigation  consisting  in  separating  a  mass  of  radio- 
active substance  into  two  portions  by  chemic  :M'oces.-es  and  testing  the 
activity  of  each  portion.  The  portion  more  highly  radio-active  is 
>ubjected  to  further  chemic  analysis,  until  finally  a  very  small  residue 
of  very  hiiihly  radio-active  substance  is  obtained. 

It  was  in  thi-  way  that  the  discovery  of  radium  was  made.  In  its 
pure-t  salts,  the  bromid.  chlorid.  and  sulphate,  its  radio-activity  is 
from  l.SOO.OOO  to  '2. 000. 000  times  that  of  uranium. 

Metallic  radium  ha-  been  obtained  by  Mine.  '  'urie  and  M.  Dubierne 
through  the  distillation  of  an  amalgam  of  mercury  and  radium  pre- 
vioii-ly  obtained  by  electrolysis.  It.-  atomic  weight  is  a  fraction  less 
than  ±>(i. 

Properties  of  Radio-active  Substances. — Thevgiveout  a  radiation 
and  -omc  of  them  '.rive  an  emanation,  which  both  have  peculiar  proper- 
ties. Taking  radium  a-  the  radio-active  substance  ot  urealest  import- 
ance, j;  i-  found  that  it  generates  heat  iii  it. -elf  without  any  apparent 
•  combmat  ion,  and  t  he.-e  are  i  he  onl v  subM  an ces  which  are  known 
•  '>  produce  heai  in  this  wa v  without  the  applical ion  of  any  outside  force. 
A  -pee imen  of  radium,  whet  her  perfectly  protected  from  the  atmosphere 

',  i',    con.-tantlv    maintains    a    temperature    i'°   or   i!°   ( '.   higher   than 
r  oi    it  -  -urroundimis.      Thi-  heat .  of  course,  radial  es  trom  t  he  ra<  hum 
ectiotis,    as    11    would    from    anv   oihei1   substance   will    a    tem- 
'']:•    higher  than  its  surroundings.      Its  evolution  is  continuous  and 
pi  mifonii,  and  i-  not   accompanied    by  any  perceptible    lo-s   of 

'  'alciilation-  have  shown  that  the  en  t  ire  radial  ion  of  lieal  from 
a  me  that    WOill' !  occur  from  a   s  pi  i  ere  ot   the  -a  me  -i/e  con- 

l       •    .   of    radium    per   cubic    meter    i  I .")    'jr.    per   cubic   yard). 
'    heat,  however,  i-  not    'he  mo.-t    important   part   of  the 
prop'          km  iwn  as  ra>  lio-act  i\"H  v. 

ii::   '•<>}          '       maintain-  a  negative  elect  ;-ic  state,  and  radio- 
• .     the  r»nl\    one-   v.-hi'-h   do  become  spontaneou.-ly 


RADIUM 


1241 


charged  with  electricity.  It  has  the  property  of  charging  substances 
with  negative  electricity,  both  those  which  are  in  contact  with  it  and 
those1  at  a  distance1.  It  also  has  the  property  of  ionizing  air  or  other 
gases  and  liquids. 

The  current  of  electricity  generated  by  a  surface  of  2',  square  centi- 
meters of  barium  chlorid  containing  a  great  eleal  of  radium  and  of  a 
thickness  of  .2  centimeter  is  about  T>O,OOO,OOU,OOO  U111P('1V-  This  repre- 
sents an  amount  of  electric  ene-rgy  eejual  to  about  1(MH)U()0|)  ^  att. 

Radium  could  never  serve  any  practical  purpose  as  a  source  of  heat 
or  electricity,  the  quantities  of  both  being  so  very  small  in  comparison 
with  its  cost. 

The  Radiation  from  Radium. — This  consists  of  three  distinct 
kinds  of  ravs — the  alpha,  beta,  and  gamma  rays — which  have  entirely 
different  properties.  The  diagram  shows  the1  way  in  which  these1  differ- 
ent rays  are1  ai'fecteel  by  the  action  of  a  magnet.  The  olplia  /Y///.S-  are 
deviates!  to  only  a  slight  degree1  and  away  from  the  magnet.  They  are 
deflectiMl  in  the  same  elirection  as  the1  Canal  Si  rahlen  (Goldstein),  or  in  the 
opposite*  direction  from  that  in  which  cathode1  rays  would  be1  deviated. 

The1  !H  In  /Y///.S  are  deviated  in  the  same'  direction  as  that  in  which 
cathode  rays  would  be  deviated — /.  c.,  toward  the'  magnet — and  are-  seen 
in  the1  illustration  to  be'  brought  around  set  as  to  impinge  vertically  upon 


the  plane1  from  which  they  start.  Some  of  them  are  more1  deviablc 
than  others  and  strike  the  plane  nearer  to  the  radium  than  others. 

The  tfitnittirt  /Y///X  are  not  deviated  at  all  under  the  magnetic  in- 
fluence. 

The  radium  in  the  illustration  is  supposed  to  be  at  the  bottom  of  a 
deep  cylindric  hole  in  a  heavv  block  of  lead.  Practically  .-peaking,  all 
t  lie  rays  would  emerge  as  a  slight  ly  divergent  bundle  of  perfectly  ,-t  raight 
lines,  but  thev  are  subjected  to  a  sort  of  analysis  by  the  selective  action 
of  the  magnet  upon  the  different  kinds  of  rays  that  go  to  make  up  the 
whole  radiation.  The  radium  gives  out  this  radiation  in  straight  lines 
in  everv  direct  ion,  but  in  the  ill  ust  rat  ion  t  he  lead  is  supposed  to  be  thick 
enough  to  absorb  practically  all  the  rays  except  those  directed  toward 
the-  opening. 

None  of  the  alpha,  beta,  or  gamma  rays  are  subject  to  refraction  or 
reflect  ion. 

They   all   produce   electric,    chemic,    photographic,    and   physiologic 


1242  MKDICAL    KLK<  TK1CITY    AND    KONTOKN    HAYS 

effects,  and  all  penetrate  substances  opaque  to  ordinary  light.  The 
different  kind-  of  rays,  however,  have  these  properties  to  very  different 
degrees. 

The  alpha  rays  are  believed  to  consist  of  particles  of  matter  which, 
although  almost  incredibly  small,  are  still  quite  large  as  compared  with 
the  particles  that  make  up  the  beta  rays.  They  travel  at  a  speed  of 
thousands  of  miles  a  second,  but  still  at  a  slow  rate  as  compared  with 
the  beta  rays. 

They  cany  an  electric  charge  as  great  as  the  negative  charge  carried 
by  the  beta  rays.  As  a  result  of  the  great  size  of  the  alpha  particles 
compared  with  their  velocity  and  their  electric  charge  the  alpha  rays  are 
but  slightly  deviated  by  a  magnet.  They  travel  to  a  distance  of  only 
about  o..">  cm.  or  l^,,  inches  through  the  air  from  the  radium  from  which 
they  radiate  and  they  penetrate  only  the  thinnest  metallic  screens.  They 
are  practically  all  absorbed  by  a  sheet  of  aluminum  -y-,/,,  or  -^fa  mm. 
(  '7,\>G  or  j.,Vu  inch)  thick,  or  by  *  mm.  of  glass,  the  thickness  of  the  wall 
of  the  smallest  glass  tubes  in  which  powerful  specimens  of  radium  are 
sold.  They  have  great  similarity  to  the  canal  rays  present  behind  the 
cathode1  of  an  x-ray  tube.  Chadwick,  working  in  Rutherford's  labora- 
tory in  the  University  of  Manchester,  has  shown  that  alpha  rays  falling 
upon  ordinary  matter  may  produce  gamma  rays.  Alpha  rays  constitute 
the  greater  part  (04  per  cent.)  of  the  radiation  from  radium. 

The  beta  rays  consist  of  particles  of  matter  calculated  to  be  about 
,  0V(>  the  size  of  a  hydrogen  atom,  traveling  at  a  velocity  of  20,000  miles 
a  second,  carrying  a  charge  of  negative  electricity,  and  being  greatly 
deviated  by  a  magnet  in  the  same  direction  as  the  cathode  rays  in  a 
( 'rookes  tube.  Some  of  the  beta  rays  are  more  (leviable  than  others  in 
consequence  of  differences  in  their  velocity.  A  piece  of  photographic 
paper  laid  along  a  line  be!  >w  the  word  maf/nct  in  the  illustration  would 
be  affected  along  a  band  starting  from  the  lead  receptacle  and  extend- 
ing outward  for  a  considerable  distance.  The  paths  of  the  beta  rays  are 
bent  by  the  action  of  a  magnetic  field  of  2o()()  units,  so  that  practically 
none  of  t  hem  can  reach  a  distance  of  more  than  70  mm.  from  the  radium. 
Th<-y  are  very  penetrating,  but  suffer  a  certain  amount  of  absorption 
in  pas.-ing  through  solid  substances  or  the  air.  and  those1  that  get  through 
are  generally  slowed.  They  produce  a  demonstrable  effect  at  a  distance 
of  2  or  :•>  meters  or  yards  if  not  deflected  by  a  magnet  or  absorbed  by  some 
solid  screen.  They  constitute  about  24  per  cent,  of  the  radiation  from 
radium.  They  are  very  similar  to  the  cathode  particles  in  an  .r-ray  tube 
whose  impact  gives  rise  to  the  Rontgen  ray. 

<  >nly  a  small  part  of  the  beta  rays  are  of  a  highly  penetrating  char- 
•  ter  and  extend  to  a  considerable  distance  through  the  air.  They  are 

ested    by   thick    sheets   of   metal.      The   distance   at    which   they   are 

elective  is  influenced  partly  by  the  absorption  they  undergo  in  passing 

.  •_  :    the  air  and  partly  by  t  he  fact  t  hat  1  he  intensity  varies  inversely 

•i  ;;  i.'irr  of  the  distance  from  the  point  from  which  the  radiation 

tak--    place. 

Absorption  of  Beta  Rays  by  the  Air. — There  are  hard  and  soft  beta 
ray-,  and  d!  irradations  between  these.  Their  absorption  by  air  is  at 
lh«'  rate  n  imately  1  or  2  per  cent .  for  each  centimeter  traversed. 

Measurement  of  the  Velocity  of  Beta  Rays.-  Hecquorel's  original 
method  places  tl  e  radium  in  a  narrow,  deep  lead  receptacle  with  a  linear 
orifice.  Above  t!  •  at  some  distance,  is  a  diaphragm  with  a  linear  orifice 


KADI  I'M  1243 

at  u  right  angle  to  the  other.  A  magnetic  field  of  a  known  strength  causes 
(lifl'eivnt  parts  of  the  sheaf  of  l)eta  rays  to  deviate;  more  or  less  as  evi- 
denced by  the  action  upon  a  photographic  film  placed  beyond.  The 
deviation  indicates  velocities  of  from  90,000  to  180,000  miles  per  second. 

The  beta  particles  have  various  initial  velocities,  slower  ones  being 
the  more  absorbable.  They  all  undergo  a  reduction  in  velocity  in  passing 
through  matter.  \V.  Wilson1  finds,  for  instance,  that  beta  rays  which 
start  from  radium  with  a  velocity  of  2.85X10  "'  (/.  e.,  10,000,000,000) 
cm.  per  second  are  slowed  to  2.55X10  '"  cm.  per  second  by  passing 
through  1.5  mm.  of  aluminum. 

The  alpha  and  beta  rays  are1  those  which  are  chiefly  effective  thera- 
peutically  for  surface  work,  and  their  properties,  enumerated  above, 
mala1  it  desirable  that  the  radium  should  be  directly  in  contact  with  the 
surface  or  only  separated  from  it  by  the  thinnest  practicable  covering. 

Origin  of  Beta  and  Gamma  Rays. — The  atom  of  a  radio-active  sub- 
stance consists  of  rings  of  negative  electrons  surrounded  by  a  positive 
charge,  but  in  an  unstable1  condition,  akin  to  a  velocity  of  rotation  such 
that  centrifugal  force  exceeds  cohesion.  According  to  Rutherford,2 
there1  are  two  types  of  instability — the  first  leads  to  the  expulsion  of  an 
alpha  or  positive  particle1,  the  seconel  to  the-  appearance  of  beta  and 
gamma  rays.  A  beta  particle  in  escaping  from  the  atom  passes  through 
the  rings  external  to  the  one  from  which  it  springs,  and  at  each  ring  it 
loses  part  of  its  energy  in  exciting  erne  or  several  gamma  rays. 

The  Gamma  Rays. — These  are1  not  deflected  by  a  magnet,  but  travel 
in  straight  divergent  lines  from  the  point  from  which  they  radiate.  They 
are1  highly  penetrating  and  are1  not  entirely  arrested  by  2  or  3  cm.  (about 
1  inch)  of  lead  or  glass.  They  do  not  consist  of  material  particle's,  but 
are-  of  the  same  nature  as  the  .r-ray,  and  are,  therefore,  supposed  to  be  a 
form  of  motion.  Their  velocity  is  the  same1  as  that  of  light.  They  are 
less  active  physiologically  than  the1  other  radium  rays,  it  being  a  general 
truth  in  regard  to  radiations  that  the  effect  occurs  only  where  they  are 
absorbed.  They  form  10  per  cent,  of  the  radiation  from  radium. 

Some1  gamma  rays  are  more1  penetrating  than  the  most  penetrating 
.r-rays  from  a  Crookes  tube.  ()udin:!  says  that  he  lias  seen  a  glass  tube 
containing  .75  gm.  of  pure  radium  bromid  in  Curie's  possession  bril- 
liantly illuminate  a  barium  platinocyanid  screen  through  a  thick  sheiet 
of  lead.  There  are  all  degress  of  penetration  in  these1  gamma  rays. 

Interesting  Theories  About  Radium. — Frederick  Soddy'  considers 
the1  following  as  probably  occurring  in  the  evolution  of  the  elements: 
rranium  change's  into  radium,  radium  into  emanation  and  successive1 
products,  lead  changes  into  silver,  and  these  change's  are1  spontaneous. 

Radio-activity  and  the  Internal  Structures  of  the  Earth. — An  exami- 
nation of  a  great  many  rocks  and  minerals  shows  a  greater  amount  of 
radium  than  would  be  necessary  to  maintain  the  internal  temperature 
of  the  earth  if  it  contained  that  proportion  all  the  way  through.  There1 
cannot,  therefore,  be  the  same  percentage1  of  radium  below  a  e-ertain 
elepth.  This  is  apropos  of  Rutherford's  observation  that  the1  earth  con- 
tains enough  radium  to  account  for  its  internal  heat.  Rutherford  ex- 
amined many  rocks  and  minerals  iR.  -I.  Strutt). 

1  Proc.  Royal  Sor.,  s4.   1910.  p.  141. 
-  Le  Radium,  9.  October,  1912.  :«7. 

3  Ibid..  Sept..  190(5. 

4  Congress  of  the  British  Association,  19fXi. 


1214 


MKIHCAL    ELECTRICITY    AND    RONTGEX    RAYS 


The     Radiation     from    Different    Radio-active    Substances.  —  Ra- 

dium uives  out  alpha.  beta.  and  gamma  rays:  polonium  gives  out  only 
alpha  rays:  actinium  give<  out  alpha,  beta,  and  probably  gamma  rays; 
ura!iium  gives  out  alpha  and  beta  rays;  thorium  gives  out  alpha  and 

The  Ionizing  Effect  of  Radiation 
from  Radio-active  Substances.-  The 
air  in  which  radium  is  placed  is  ionized 
and  becomes  a  conductor  of  electricity. 
This  effect  may  be  shown  in  two  dif- 
ferent ways:  one.  by  charging  an  elec- 
troscope with  stat  ic  electricity  and  not- 
ing the  fall  of  the  divergent  gold  leaves 
as  the  electroscope  becomes  discharged  ; 
the  other  consists  jn  measuring  the 
electric  current  from  a  battery  which 
will  pass  across  an  ail1  space  introduced 
in  the  circuit  (Fig.  <S46). 

The  lirst  method  is  very  convenient  for  testing  a  substance  for 
radio-activity  and  may  serve  even  as  a  quantitative  indication.  The 
other  method  is  the  one  adopted  for  the  very  delicate  tests  by  which  the 
radio-activity  of  radium  is  measured.  A  suitable  arrangement  of  an. 
electroscope  for  use  in  testing  radio-activity  consists  of  a  metal  cylinder 
with  two  windows,  covered  by  wire  gauze  to  prevent  currents  of  air.  but 
allowing  observation  of  the  interior.  Tne  electroscope  itself  is  formed 
of  a  metal  rod  which  projects  through  the  top  of  the  cylinder,  where  it 
i-  surrounded  by  a  non-conducting  collar.  Parallel  with  its  lower  por- 
tion there  is  a  strip  of  1:0  Id  leaf  which  is  free  to  diverge  from  it.  The 
arrangement  for  charging  the  electroscope  is  a  bent  rod  projecting 
through  another  insulated  opening  in  the  top.  and  which  is  normally 
helil  apart  from  the  electro-cope  by  the  action  of  a  spring. 

A  rod  of  amh'T  or  hard  rubber  is  rubbed  on  silk  or  wool  and  touched 

to  the  cute]-  end  of  the  charging  rod.  which  is  held  in  contact  with  the 

electro-cope  and  then  released.      'I  he  gold  leaf  becomes  widely  diverg- 

ent. MIH  !  under  ordinary  circumstances  would  remain  so  for  a  considerable 

lengt  h  of  time.     The  substance  to  be  tested  for  radio-act  ivity  is  placed  in 

a  tray,  which  is  now  applied  at  the  bo  t  torn  of  the  c\  Under.     The  air  in 

the  cylinder  becomes  a  conductor  in  consequence  of  an  ionizing  influence 

if   the  substance,   i.-   radio-active.      1  he  >tat;c   charge  is   carried   by   the 

;,'/  from  the  electroscope  to  the  metallic  wall  oi   the  cylinder  and  the 

'_n>Id   leaf  fall.-   into   contact    with   the   vertical   rod   of  the  electroscope. 

The  time  'hat    thi-   requires   furnishes  a   certain   measure  ol   the  radio- 

'i    itv    rif    the   substance.      A    telescope   with    a    micrometer   eyepiece 

•-  bi    used  to  mea.-ure  the  exact   rapidity  at  which  the  gold  leal  tails. 

A    -creen   i  if  any   kind  nuiv   be  introduced  above  the  radio-active  sub- 

ithi  ••  for  the   purpo.-e  of  testing  the  effect    of  various  screens 

:••-:•.<••  i  \-  it  \-  ot'  i  he  -a  me  Mibst  ance.  or  as  a  mean.--  ol  reducing 

•  vitv  of  a  standard  substance  or  of  the  substance  to  be 


Curie's   Electrometric   Apparatus   for    Measuring   Radio-activ- 


124.-) 


from  it   by  a  small  air  space.      This  upper  plate  is  connected  with  the 
earth  through  an  electrometer  and  a  quart/  electric  balance. 

The  action  of  the  battery 
results  in  the  lower  horizontal 
plate  being  raised  to  a  potent  ial 
of  a  certain  number  of  volts. 
The  air  between  the  two  plates 
being  a  non-conductor,  no  cur- 
rent passes  to  the  upper  plate, 
and  consequently  the  elec- 
trometer connected  with  that 
shows  no  deviation.  Now  a 
radio-active  substance  is  placet  1 
upon  the  lower  horizontal  plate 
and  the  air  between  the  two 
plates  becomes  a  conductor  ot 
electricity.  A  complete  circuit 
is.  therefore,  established  from 
OIK'  pole  of  the  bat  tery  tot  he 
lower  plate,  through  the  air  to 
the  upper  plate,  and  through 
the  electrometer  and  the  earth 
to  the  other  pole  of  the  battery. 
The  strength  of  the  current,  as 
indicated  by  the  electrometer, 

sinnvs   the  degree  to    which    the   air  has  been  ionized  and  the  radio- 
activity of  the  substance  winch  is  being  tested. 

For  exceedingly  weak  currents  the  quart/  electric  balance  is  used  to 
exactly  counterbalance  the  electromotive  fo1  ce  of  the  battery  and  to 
prevent  the  passage  of  any  current  through  the  electrometer. 

Electromotive  foice  generated  by  the  quart/  electric  balance  is 
susceptible  of  very  delicate  adjustment. 

It  is  sometimes  desirable  to  first  establish  a  direct  connection  be- 
tween the  upper  plate  and  the  earth,  which  is  broken  after  the  electric 
current  has  begun  to  flow  in  a  uniform  manner. 

Standard  specimens  of  different  radio-activity  are  required  for 
comparison,  ami  different  screens  may  be  Used,  or  the  specimens  of 
radium  may  be  placed  at  a  measured  distance  from  the  two  plates 
instead  of  directly  between  them. 

The  static  electroscope  is  used  chiefh 
radio-activity.  The  apparatus  in  Fiir.  M7 
Co..  is  designed  to  detect  a  radio-activi 
I'-ed  without  a  magnifying  ula<-  it  shows 

Current  Electroscope  of  Zeleny.'—  Thi- 


used  for  tc.^tinu:  radio-activity 


to  te<t   various  minerals  for 
made  by  AYaite  and  F>artlett 
y   of    .  „'„  n    t  hat    of   uranium, 
a  radii  Kid  ivity  of     ,; . 
i-  mi  1  he  principle  t  if  a  static 

electric  pendulum.  One  terminal  i-  charged  to  a  potential  of.  say.  100 
volts.  A  swinging  sheet  of  u'old  foil  is  attracted  to  it  and.  receiving  a 
charire.  is  repelled,  but  as  it  is  connected  with  an  ioni/inir  -pace  it  loses 
charge  and  is  au'ain  attracted.  The  number  of  excursions  per  minute 
f  the  sireiiiith  of  the  ioni/iiiir  substance, 
trument  i<  the  one  Used  for  testing  th 
radium  ramrinu;  from  1000  to  1  .SOO.I 


it 


124f>  MKDICAL    KLFJTKM  1TY    AM)    KOXTOKX    KAYS 

The  International  Radium  Standard. — The  one  adopted  was  pre- 
sented to  the  International  ( 'ommission  by  Madame  Curie,  and  contains 
'2'2  mg.  of  pure  radium  bromid  in  a  sealed  "'lass  lube  almost  completely 
filled. 

Measurement  of  the  Radio-activity  of  Specimens  of  Radium  as 
Compared  with  a  Standard  Specimen. —  .lust  as  all  the  linear  measures  in 
a  country  are  based  upon  a  comparison  with  a  carefully  prepared  and 
permanently  preserved  national  standard  meter  or  yard  measure.  K. 
Rutherford1  thinks  an  international  standard  of  radio-activity  should  be 
preserved.  The  standard  specimen  should  be  weighed  and  kept  in  a 
sealed  »'lass  tube  of  known  size  and  thickness  of  walls. 

The  most  reliable  comparative  measurement  of  radio-activities,  which 
are  very  unequal,  is  by  compensation.  Two  ionizing  chambers  are  used, 
both  connected  with  the  electroscope  in  such  a  way  that  the  current  tends 
to  pass  through  one  and  is  opposed  by  the  other  ionizing  chamber. 
Equal  ionization  in  both  chambers  is  indicated  by  an  absence  of  current 
through  the  electroscope.  In  one  chamber  a  plate  of  uranium  oxid  is 
used  as  a  constant  source  of  ionization.  The  first  part  of  the  measure- 
ment consists  in  measuring  the  distance1  at  which  the  standard  speci- 
men of  radium  must  be  placed  in  order  to  exactly  counterbalance  the 
ionizing  effect  of  the  plate  of  uranium  oxid.  Then  the  same  test  \s 
made  with  the  radium  under  examination.  The  activities  of  the  two 
specimens  of  radium 'arc1  directly  proportional  to  the  square  of  the  dis- 
tance at  which  they  will  produce  the  same  effect. 

This  measurement  is  based  almost  entirely  upon  the  effect  of  gamma 
rays,  and  caution  must  be  employed  to  detect  the  presence  of  mesothor- 
ium  which  might  produce  an  equal  strength  of  this  radiation  at  a  cheaper 
cost.  This  may  be  detected  by  dissolving  the  supposed  radium  salt  in 
water  and  boiling  for  several  hours  to  drive  off  all  emanation.  Exam- 
ined immediately  afterward,  the  radiation  from  radium  will  be  free  from 
gamma  rays,  while  1  hat  from  mesothorium  will  contain  them  abundant  ly. 

A  substance  of  very  low  radio-activity,  like  mineral  waters,  is  tested 
by  a  comparison  of  its  emanation  with  that  from  a  standard  solution 
containing,  say,  10  '"  grammes  of  radium  to  the  cubic  centimeter.  This 
solution  is  perfectly  stable,  especially  if  a  small  amount  of  hydrochloric 
acid  is  added. 

Radium  Testing  by  Photographic  Effect. — The  author  finds  this  ex- 
cellent for  practical  therapeutic  work. 

The  Tousey  Unit  of  Power.-   This  is  the  photographic  effect  upon 

kodak  film  by  1   candle-power  incande-cenl    electric  light  with  a  carl  ion 

filament,    and    with    the    usual    blight  ness    or    whiteness.      One    Tousey 

meter  -erond  i-  the  effect    produced  by  such  a   light   at   a  distance  of    1 

from  kodak  film  in  one  -erond.      For  actual  measurement  a  port  ion 

•  c  him  mav  be  previously  exposed  to  1   Tousev  meter  second  of  m- 
caiii  '    ceni  elect  ric  lio hi .  and  ol  her  port  ions  are  exposed  to  the  specimen 
employing  the  condition-  under  which  it   is  to  be  used.      For 
•    of  the  author'-  radium  instruments  i-  a  small  glass  tube, 
approximately    'JO    milligrams   of    radium    with    an   approxi- 
nf   '_>. (Kill. OIK).       This    i-    placed    close   to   the   kodak    film, 
Mr-fare  up.  but    the  film  covered  bv  two  thicknesses  of  black 
portions  are  exposed  to  the  radium  for  various  num- 

'    'i>  :•<•!!    \"(-r\'.-cn(Iuntr    !>'•!   r;i<lio;tktivrii   Mrs-iin^cn. 
•.    \  .  i'!.-nii",  <  Ir-i-llsHinft,  I.icp-iir,  P.M  1. 


RADIUM  1247 

bers  of  seconds,  protecting  every  other  part  with  heavy  lead  during  each 
exposure.  The  entire  film  is  developed  in  M.  Q.  developer  of  regular 
strength,  for  ten  minutes,  in  complete  darkness.  The  portion  exposed 
to  the  radium  for  5  seconds  is  as  dense  black  as  the  portion  exposed 
to  1  Tousey  meter  second  of  incandescent  electric  light.  This  specimen 
is  of  maximum  power,  and  a  contact  application  of  the  glass  tube  will 
produce  a  pronounced  dermatitis  after  about  five  minutes,  which  natu- 
rally is  about  the  time  limit  of  its  application  until  the  period  of  cumu- 
lative effect,  say  two  or  three  weeks,  shall  have  elapsed.  The  same  spec- 
imen of  radium,  tested  in  an  aluminum  treatment  tube  with  walls  ./ 
mm.  thick  would  require  longer  application  to  equal  1  Tousey  meter 
second,  and  could  be  applied  for  three  times  as  long  without  producing  an 
excessive  reaction  upon  the  skin;  and  since  the  radiation  is  of  greater 
average  penetration  there  would  be  a  greater  deep  effect  from  this  longer 
filtered  irradiation.  Lead  screens  are  often  added  to  secure  still  greater 
average  penetration  by  arresting  the  beta  and  transmitting  only  the 
gamma  rays,  and  the  safety  limit  and  effectiveness  of  the  application  may 
be  measured  in  the  same  way. 

A  sheet  of  lead  %  mm.  thick,  and  weighing  an  ounce  to  12  square 
inches  in  addition  to  the  glass  tube  and  the  aluminum  treatment  tube, 
increases  the  permissible  time  of  exposure  to  18  times  that  for  the  glass 
tube  alone,  or  6  times  that  for  the  glass  and  aluminum  tubes  combined. 

Analysis  of  the  Radiation  from  the  Author's  Radium  Applicator  No.  4 
(20  milligrams,  2,000,000  Activity). — The  bare  radium  salt  would  give 
rays  in  the  proportion  of— 

Alpha 00  per  cent. 

Beta 0  per  cent. 

Gamma 1  per  cent. 

100  per  cent. 

Enclosed  in  a  glass  tube  of  0.3  mm.  wall  thickness,  about  2  mm.  di- 
ameter, all  the  alpha  rays  are  absorbed  in  the  salt  and  the  glass  walls, 
also  50  per  cent,  of  the  beta  rays  and  1  per  cent,  of  the  gamma  rays;  this 
leaves  a  ratio  of — 

Alpha.. 

Beta 

( lamina .  . 


and  this  new  total  is  composed  of  only  about  55  per  cent,  of  the  original 
total  radiation. 

An  additional  screen  of  aluminum,  ]  mm.  thick,  cuts  down  the  beta 
rays  about  50  per  cent,  and  the  gamma  rays  about  1  per  cent.,  leaving 
the  following  ratio: 


The  further  addition  of  a  lead  screen,  ^  mm.  thickness,  changes  the 
ratio  to — 


1 248 


MEDICAL    KI.KCTKH  ITY    AND    HONTGEX    KAYS 


And  o  nun.  of  lend  transmits  prncticnlly  nothing  but  gamma  rays. 

Applied  to  ol  her  specimens  of  radium,  the  object  is  first  to  measure  the 
time  of  exposure  required  to  produce  1  Tousey  meter  second  effect  upon 
kodak  film.  The  radio-activity  of  the  specimen  may  be  calculated  from 
a  comparison  of  the  exposure  it  requires  to  produce  the  same  effect  as  the 
author's  20  milligrams  of  2. 000, 000  radio-activity.  The  erythema  dose 
and  deep  effect  under  different  conditions  as  to  filter  may  be  calculated 
in  the  same  way. 

Radium  Measurement  by  Sabouraud  and  Noire  Pastilles  of  Barium 
Platinocyanid. —  Such  a  specimen  of  pure  radium  salt  in  a  "'lass  tube 
changes  a  pastille  to  Tint  ti  in  about  five  hours,  whereas  five  minutes 
contact  produces  an  extreme  erythema  dose. 

Electroscope  and  lonization  Chamber  for  Measuring  Radio-activity. 

—The  utilization  chamber  1 1$\  of  brass  is  about  1 1  cm.  in  diameter  and  S.\ 

cm.  high.      Through  the  top  passes  a  thick  amber  spool  insulating  and 


, 

1 

mi 

~D 

[ 

-fi 

B 

t 

fe 

m 

— 

E 

-upporting  the  electroscope  /.     The  charging  wire,  shown  separately,  is 

i>a--rd  t  hrouii'h  the  hole  in  the  amber  spool  and  i-  withdrawn  when  the 
•_:  •!>  i  leaf  i-  -ecu  tn  di  vi  rue.  \\  iiid<  >ws  at  oppo>H  e  side^  ol  the  ionixiition 
lier  allow  of  observation  through  the  microscope  indicated  by  the 
dotted  circle  //'.  Screeii>  (it  dillereiil  materials  mid  thickness  mny  be 
inl  I'oduced  t  hroiiiili  the  -lit  A'.  The  -teli  i  /  of  t  he  elect  1'oscope  is  a  brass 
rod  1  mm.  i  hick  and  '.\  cm.  loiiu1.  t  he  u'old  leaf  ha  \  iuu  t  he  .-a me  dimensions. 


ORIGIN   AND   COST   OF   RADIUM 

in  -inall  i  iiia  ni  it  ie.-  in  inaii\'  diflerent   iniiieral-  found 


KADIUM  1249 

springs.  For  practical  purposes  it  is  extracted  from  pitchblende,  a 
heavy  black  mineral,  looking  somewhat  like  anthracite  coal,  but  break- 
ing with  a  smooth  fracture  without  jagged  corners  or  edges.  <  )ne  of  the 
principal  deposits  of  pitchblende  is  at  Joachimst hal  in  Bohemia.  This 
mineral  contains  uranium  oxid,  which  is  extracted  from  it.  The  residue 
at  a  certain  stage  of  this  process  contains  the  radium  of  the  original 
mineral  in  quite  a  concentrated  form,  but  still  closely  associated  with 
a  do/en  or  more  other  elements. 

The  treatment  of  a  ton  of  this  residue  requires  5  tons  of  various 
chemicals  and  50  tons  of  water.  The  product  is  about  1  gram  (15  gr.j 
of  pure  radium  bromid,  with  a  radio-activity  of  2, 000, 000. 

From  500  tons  of  the  ore  (carnotite.  etc.)  1  gram  of  radium  is  obtain- 
able1, a  concentration  of  100, 000. 000  is  therefore  required. 

The  price  at  which  this  was  sold  in  1909  was  $80,000,  or  400,000  francs, 
or  L'15,500,  and  the  price  has  increased  50  per  cent,  in  1014. 

Smaller  quantities  are  sold  at  a  corresponding  fraction  of  the  price 
per  gram. 

The  best  manufacturers  prepare  the  less  powerful  specimens  of 
radium  bromid  by  taking  a  certain  percentage  of  pure  radium  bromid 
and  adding  the  necessary  amount  of  barium  bromid.  The  price  is  a 
corresponding  percentage  of  that  of  the  same  quantity  of  pure  radium 
bromid. 

One  decigram  (I1,  gr.)  of  pure  radium  bromid  with  an  activity  of 
2,000.000  costs  $12,000  in  1914. 

O-ne  decigram  of  radium  bromid  of  ISO. 000  activity  (containing, 
therefore,  10  per  cent,  of  pure  radium  bromid)  costs  81200. 

One  decigram  of  radium  bromid  of  20,000  activity  costs  8120. 

( )ne  gram  (15  gr.)  of  radium  bromid  of  a  radio-activity  of  only  50 
(Y.  c.,  fifty  limes  that  .of  uranium)  costs  8l>. 

The  other  radium  compounds. — c.  ;/.,  the  sulphate  and  the  chlorid — 
are  prepared  in  various  strengths  and  sold  at  prices  corresponding 
with  the  radio-activity  of  each  specimen. 

VARIATIONS   IN  THE   RADIO-ACTIVITY   OF   RADIUM 

The  purest  radium  salt  does  not  present  any  marked  radio-activity 
when  it  is  first  extracted  from  the  mineral  containing  it.  The  property 
develops  in  a  short  time  if  the  radium  salt  is  kept  in  a  closed  glass  tube 
or  similar  air-tight  container,  and  its  full  act  ivit y  is  developed  in  three  or 
i'( ui!'  wi 'eks. 

It  is  supposed  that  the  development  of  radio-activity  under  these 
circumstances  is  due  to  the  storing  up  of  the  emanation  in  the  radium. 
The  emanation,  which  is  to  be  described  in  detail  on  a  subsequent  page, 
is  a  sort  of  vapor  which  arises  from  radium.  fi  cannot  pass  through 
glass  and  passes  only  very  >!owly  through  a  capillary  tube,  it  renders 
radio-active  any  substance  by  which  it  is  absorbed. 

Radium  which  is  enclosed  in  an  air-t ight  container  of  metal,  glass,  or 
rubber,  or  if  covered  by  varnish  preserves  its  radio-activity  unchanged 
for  years  at  ordinary  temperatures. 

Exposure  to  the  air  does  not  cause  any  great  loss  of  radio-activity 
in  the  case  of  radium  salts  which  are  in  the  solid  state,  but  it  does  occa- 
sion a  secondary  loss  if  the  radium  salt  is  hygroscopic  and  absorbs 
enough  moisture  to  be  liquefied. 

70 


1250 


MEDICAL    ELECTRICITY    AND    RONTGEN    KAYS 


Effect  of  Temperature  Changes. — Mine.  Curie  has  found  that 
radium  loses  10  per  cent,  of  its  activity  if  kept  at  a  temperature  of  130° 
C.  for  an  hour,  but  that  a  temperature  of  400°  C.  for  only  ten  minutes 
produces  no  noticeable  effect.  If  maintained  at  a  red  heat  for  several 
hours  a  radium  salt  loses  70  or  80  per  cent,  of  its  activity.  This  radio- 
activity is  regained  gradually,  and  at  the  end  of  two  months  or  so  it  is 
usually  even  greater  than  it  was  originally. 

A  red  heat  causes  the  emanation  to  almost  completely  disappear 
from  a  specimen  of  radium,  and  with  it  the  property  of  inducing  radio- 
activity in  other  substances.  These  may  be  at  once  completely  restored 
by  dissolving  the  radium  salt  in  water  and  drying  it  at  a  temperature  of 
120°  C.  The  salt  may  then  have  its  full  property  of  emanation,  caus- 
ing radio-activity  in  other  substances  even  before  it  has  fully  regained 
its  own  radio-activity. 

Effect  of  Solution. —  Dissolving  a  radium  salt  causes  the  liquid 
to  become  radio-active,  and  this  radio-activity  is  not  all  at  once  concen- 
trated again  in  the  radium  when  the  solution  is  evaporated.  The  more 
dilute  the  solution  and  the  longer  the  radium  remains  in  solution,  the 
greater  amount  of  emanation  is  abstracted  by  the  liquid  and  the  less 
radio-active  the  radium  salt  is  found  when  dried.  If  the  solution  has 
been  exposed  to  the  air  for  a  number  of  days,  much  of  the  radio-activity 
of  the  solution  is  lost.  After  evaporation  it  is  found  that  the  dried  salt 
is  less  radio-active1  than  if  the  solution  had  been  exposed  to  the  air  for 
a  shorter  time  or  had  been  kept  in  a  sealed  glass  tube.  It  also  takes  a 
longer  time  for  the  radium  salt  to  regain  its  original  radio-activity. 

Radio-activity  seems  to  be  due  to  the  storing  up  of  the  emanation. 
The  emanation  is  not  very  readily  yielded  up  to  solids,  liquids,  or  gases 
by  radium  in  the  solid  state,  so  that  in  this  state  it  accumulates  up 
to  a  certain  maximum,  which  is  maintained. 

A  solution  of  radium,  on  the  other  hand,  very  readily  parts  with  its 
emanation,  and.  therefore,  soon  loses  a  large  part  of  its  radio-activity 

if  exposed  to  the  air.  Such  a  solution  re- 
gains its  radio-activity  if  sealed  up  so  that 
the  emanation  can  no  longer  escape,  but 
accumulates. 

The  Emanation  from  Radium.—  The 
salts  of  radium  produce  constantly  and 
uniformly  a  gaseous  substance,  which  has 
already  been  referred  to  as  the  probable 
cause  of  the  radio-activity  of  these  sub- 
stances and  of  the  communication  of 
radio-activity  to  other  substances. 

This  gas  is  also  radio-active  itself.  It 
accumulates  m  solid  radium  salts  and 
makes  them  highly  radio-active.  It  is 

•specially,  from  solutions  ot  these  salts  unless  the  solutions 
sealed  glass  tube>.  and  it  is  rapidly  liberated  from  the  solid 
the>e  are  kept  at  a  red  heat  for  about  an  hour 
"1-  \-  the  one  which  i>  used  1o  obtain  the  eman; 
nut  if  ( >r  experiment  al  purposes. 

o\vs  an  appara  t  us  for  securing  t  he  einanat 
hum  bromid  dissolved  in  water  is  placed 
connected  at  one  upturned  end  \vilh  an  aspirating 


ion.  At  least 
in  a  t  ulie.  J\', 
tube.  There 


RADIUM 


1251 


is  ;i  plug  of  absorbent  cotton  in  this  tube  at  .4,  so  that  the  air  drawn 
through  the  apparatus  contains  only  the  gaseous  emanation  without 
possible  small  particles  of  the  solution  of  radium.  The  apparatus  in- 
cludes a  water  bottle,  through  which  the  air  enters.  Being  thus  satu- 
rated with  moisture,  the  air  does  not  cause  evaporation  of  the  radium 
solution.  Other  parts  of  the  apparatus  are  a  simple  aspirating  syringe 
and  tubes  B,  f ,  and  I),  which  may  be  drawn  full  of  air  saturated  with  the 
emanation  and  preserved  for  use  at  any  time. 

Collection  of  Radium  Emanation. — The;  simple  apparatus  shown  in 
Fig.  850  shows  only  the  basic  idea.  In  actual  practice  a  large  quantity, 
500  mg.,  of  radium  chlorid  at  the  Huntington  Memorial  Hospital,  and 
3  gm.  at  the  Radium  Research  Laboratory  of  the  Standard  Chemical 
Co.,  of  Pittsburgh,  are  dissolved  in  a  small  quantity  of  very  dilute 
hydrochloric  acid.  The  vessel  containing  this,  stationary  in  a  safe,  has 
a  tube  leading  out  to  a  complicated  system  of  tubes  and  bulbs  and  stop- 
cocks connected  with  an  air  pump.  First  a  vacuum  is  created  in  a 
vessel  into  which  the  accumulated  emanations — water  vapor,  hydrogen, 
oxygen,  etc. — arc  allowed  to  diffuse.  Then  dried  air  is  admitted  to 
carry  this  mixture  past  a  mercury  seal  into  vessels  where  sodium  hy- 
droxid,  an  electrically  heated  copper  oxid  spiral  and  phosphorus  pen- 
toxid  absorb  carbon  dioxid,  hydrogen,  moisture,  etc.  Then  this 
emanation-charged  air  is  compressed  into  a  tiny  long  tube  possibly 
cooled  by  liquid  air,  this  compression  being  repeated  every  few  minutes 
until  all  the  accumulated  emanation  has  been  desposited  in  the  tube, 
which  can  then  be  sealed  by  heat,  and  cut  into  different  sealed  lengths 
containing  fractional  parts  of  the  day's  accumulation  of  emanation.1 

Figure  850  shows  a  type  of  apparatus  for  the  preparation  of  radio- 
active liquids.  One  or  two  mg.  of  pure  radium  sulphate,  which  is  in- 
soluble, are  placed  in  the  open  upturned  end  of  the  tube  in  the  lower 
bottle  of  water.  As  fast  as  the  radio-active  solution  is  drawn  off  at  the 
bottom  of  the  lower  bottle  additional  water  enters  from  the  upper  bot- 
tle. The  arrangement  is  such  that  no  air  can  enter  the  lower  bottle. 


Nature  of  the  Emanation. — Niton,  or  the  emanation  from  radium,  has 
an  atomic  weight,  according  to  different  authorities — Curie,  Ruther- 
ford. Debierne.  and  others- -of  from  170  to  235.  The  theory  is  that  an 
atom  of  radium  loses  an  atom  of  helium  in  order  to  produce  an  atom  of 
emanation  which,  in  its  transformation,  loses  three  more1  atoms  of  helium. 
Radium  emanation  is  twenty  times  more  absorbed  by  organic  liquids 
like  gasoline,  alcohol,  and  benzene  than  by  water. 

1  C.  H.  Viol,  Radium,  vol.  xiv,  No.  1.  Oct..  1910.  p.  1. 


MKDir.VL    ELECTRICITY    AND    KONTCEX    KAYS 

Helium  is  spontaneou>ly  produced  by  radium  at  the  rate  of  between 
20  to  'JOO  '  probably  I.")?1  c.min.  a  year  ))er  ^.rani  of  radium.  It  is  also 
produced  by  other  substances  which  emit  alpha  rays. 

It  is  very  certain  that  helium  is  evolved  from  radium,  and  perhaps 
this  is  the  essential  part  of  the  emanation.  Helium  is  a  pis  lighter  than 
hydrogen:  it  occurs  abundantly  in  the  sun.  but  only  to  a  very  small 
extent  upon  the  earth.  <  ^  the  twelve  characteristic  lines  in  the  spectrum 
of  radium,  live  are  al-o  common  to  helium. 

The  volume  of  emanation  in  equilibrium  with  1  lira m  of  radium  is 
about  ()..")'.)  c.mm.1 

The  quantity  of  emanation  is  jireally  reduced  by  the  addition  ot 
different  acid-  and  salt-,  such  as  sulphuric  acid  and  barium  sulphate  to 
the  solution  of  radium  salt  .- 

Radio-active  Emanation  Contained  in  the  Air  Near  the  Earth. — This 
i-  derived  from  the  uranium,  radium,  and  thorium  present  in  the 
earth,  and  it- amount  is  such  that  a  cubic  meter  of  the  air  contains  an 
fimount  of  emanation  which  would  be  in  equilibrium  with  SOX10'"12 
uni.  of  radium.  '1  hi.-  i>  equivalent  to  SOX  1C  :~  curies. 

Radium  Contained  in  the  Atlantic  and  lonization  of  the  Air  Over  the 
Ocean.  .loly  has  found  about  1.1X10  !;  .mn.  of  radium  in  1  c.e.  of 
sea-water.  The  air  over  the  ocean  receives  an  insignificant  quantity 
of  u'amma  rays  and  of  emanation,  but,  nevertheless,  has  been  found  by 
variou-  observers  to  have  about  the  same  conductivity  and  number  of 
ions  as  the  air  over  the  earth.  Eve8  regards  thi-  anomaly  a-  a  serious 
objection  to  a  purely  radio-active  theory  for  the  normal  ionization  of  the 
at  nn  '-phere. 

<  >nly  the  purest  radium,  thorium,  and  actinium  salts  <rive  out  an 
effective  amount  -of  emanation.  Polonium  and  uranium  do  not  produce 
an  emaiiat  ion. 

Induced  Radio-activity.-  -Any  substance — solid,  liquid,  or  gaseous 
exposed  to  the  direct  influence  of  radium  salts  becomes  it-elf  radio- 
active, though  this  property  i-  retained  for  only  a  short  time.  The 
condition-  under  which  tin-  occurs  make  it  seem  that  it  must  be  an 
effect  of  the  ab-orption  of  the  emanation. 

The  dcctric  charge  of  t  he  a  1  ptm  rays  emit  t ed  1  >y  1  curie  of  emanation 
i-  about  '. H).s  electrostatic  units  per  second. 

A  radio-active  .-olution  is  not  the  same  a.-  a  solution  of  radium  (or  a 

rad  i  fen  HIS  solution;.     'I  he  latter  contain-  radium,  which  is  constantlv 

•  •.M:  emanation,  and  in  this  way  it   either  permanently  maintains 

j'-'-lf   in    a    radio-active   state   or   constantly   induce.-   radio-activity    in 

-ub-taiices.      ,\    radio-active    solution,    on    the    other   hand,    mav 

-i  Mply  a  -olution  in  \vhidi  radio-activity  ha.-  been  induced  liy  ab- 
:.  of  the  emanation  from  radium.  It.-  radio-activity  disappears 
ni  tins  emanation.  Kadio-act  ive  solutions  are  pre- 
i  ;  :•  immediate  use.  Itadiferous  sub.-tances— nil,  glycerin,  oint- 

licines  on  the  other  hand.  ina\'  be  l.ept  for  use  at  aiiv 


HADir.M  1253 

As  will  be  seen  later,  there  is  reason  to  believe  that  the  beneficial 
activity  of  certain  medicines  is  enhanced  by  the  addition  of  radium. 

Other  Electric  Phenomena  Connected  with  Radium. — .More 
than  once  it  has  happened  to  Mine.  Curie  and  others  that  radium 
that  has  been  long  kept  in  a  sealed  glass  tube  has  developed  a  powerful 
static  charge.  On  breaking  open  such  a  tube  a  discharge  has  occurred 
like  that  of  a  tiny  Leyden  jar  and  the  precious  particles  of  radium  have 
been  scattered  over  the  floor.  A  slight  electric  shock  is  sometimes  felt 
in  the  fingers  under  these  circumstances. 

Robert  Abbe  in  such  a  case  employed  an  ingenious  device  for  locat- 
ing the  particles  upon  the  carpet.  He  spread  a  sheet  of  sensitized 
paper  over  the  floor  and  developed  it  after  the  proper  time.  The 
paper  showed  a  chart  of  the  position  of  the  different  particles  of 
radium. 

Mereanton,1  in  order  to  open  a  tube  containing  radium  without 
danger  of  explosion,  wrapped  around  it  a  platinum  wire  heated  by 
electricity.  A  tiny  invisible  opening  was  made  in  the  tube,  as  evidenced 
by  the  radio-activity  induced  in  a  neighboring  piece  of  metal  by  the 
escaping  emanation.  A  control  experiment  showed  that  the  emanation 
does  not  escape  in  perceptible  quantities  from  an  unbroken  glass  tube. 
There  was  no  protrusion  of  the  glass  at  the  point  where  a  hole  was  fused 
in  it,  and  the  experimenter  believed  that  in  this  particular  case,  at  all 
events,  there  was  a  partial  vacuum  instead  of  an  increased  pressure 
inside  the  tube. 

Absorption  of  Radium  Rays. — The  rays  pass  through  a  vacuum  in 
very  much  the  same  way  as  through  the  air. 

The  alpha  rays  are  practically  all  absorbed  by  7  or  even  3.5  cm.  of  air. 

The  radiation  given  out  by  a  specimen  of  radium  enclosed  in  a  small 
glass  tube  produces  an  ionixing  effect  (in  the  apparatus  for  measuring 
radio-activity)  which  between  10  and  100  cm.  varies  inversely  as  the 
-quare  of  the  distance. 

Thus,  in  one  of  Mine.  Curie's  experiments,  the  current  of  saturation 
at  10.  30,  50.  1)0.  and  100  cm.  was  127.  174.  (i.9.  4.7.  and  1.115.  A  sheet 
of  aluminum  0.01  mm.  thick,  placed  almo-t  in  contact  with  a  thin  layer 
of  thorium,  transmits  3S  per  cent,  of  1  he  original  radiation.  If  radium 
is  used,  about  30  per  cent,  is  transmitted,  and  from  polonium  or  uranium, 
only  20  per  cent . 

The  highly  penetrating  ray-  from  radium  become  practically  non- 
absorbabie  after  passing  through  -event I  centimeters  of  solid  substance. 
The  alpha  ray-,  on  the  contrary,  appear  to  be  rendered  more  ab-orbable 
after  pa -sage  through  even  a  thin  metallic  screen,  just  as  if  they  con- 
-i-ti'd  of  solid  particles  which  lo-t  some  of  their  momentum. 

Absorption  of  Gamma  Rays  by  Gases  and  Light  and  Heavy  Sub- 
stances.- '  >.  Chadwick."  experimenting  with  radium  rays  which  have 
pa— ed  through  3  mm.  of  lead  'allowing  only  gamma  rays  to  pass),  finds 
that  liquid  air,  liquid  hydrogen,  and  liquid  carbonic  acid  gas  absorb 
about  5  per  cent .  of  1  he  lamina  rays  per  centimeter  of  the  liquid  1  ra  versed. 
Water,  aluminum,  wood,  and  other  li^ht  substances  absorb  from  4' 
to  5\  pel'  cent,  and  lead  about  !i  per  cent,  ol  the.-e  rays  per  centimeter. 

Comparison  Between  the  Absorbability  of  Beta  and  Gamma  Rays. — 
II: 


1254  MEDICAL    ELECTRICITY    AND    ROXTGEX    RAYS 

lead,  and  with  increasing  thicknesses  of  lead  these  beta  rays  have  about 
the  same  power  as  the  gamma  rays.  The  gamma  rays  show  a  50  per  cent. 
absorption  by  12  mm.  of  lead,  and  from  there  on  such  a  low  rate  of  ab- 
sorption that  some  may  be  demonstrated  to  pass  through  even  20  cm. 
of  lead. 

(lenerally  speaking,  harder  gamma  rays  emerge  than  enter  a  metal 
with  very  high  specific  gravity,  and  softer  with  metals  of  very  low  specific 
gravity. 

Polonium  rays  undergo  a  transformation  in  passing  through  alu- 
minum which  makes  them  less  penetrating.  M.  ('uric  found  that  a 
screen  of  aluminum.  0.01  nun.,  and  then  one  of  brass,  0.005  mm.,  thick, 
transmitted  2'  times  as  much  of  the  radiation  as  when  the  same  screens 
were  used  in  the  other  order,  brass  and  then  aluminum. 

Secondary  Rays  from  Radium. — These  are  similar  to  those  pro- 
duced by  the  .r-rays  and  cathode  rays  from  a  Crookes  tube.  Lead, 
in  particular,  gives  out  these  secondary  rays  in  a  manner  corresponding 
to  the  fluorescence  of  other  substances  under  ordinary  light.  The 
secondary  rays  have  less  penetration  than  primary  rays,  but  have  an 
equal  photographic  effect. 

A  lead  filter,  arresting  the  alpha  and  the  more  absorbable  beta  rays, 
gives  out  secondary  rays  which  are  absorbable  and  would  have  an  un- 
desirable surface  effect  during  long  application.  They  should  be  arrested 
by  a  covering  of  rubber  or  several  thicknesses  of  gauze. 

Secondary  Gamma  Rays. — These  have  the  same  heterogeneous 
wave-lentrth  as  primary  gamma  rays.  Their  existence  is  easily  proved 
1  iy  t  he  fact  t  hat  an  elect  roscope  behind  a  lead  screen,  0.7  cm.  thick,  shows 
the  presence  of  10  per  cent,  more  gamma  rays  than  when  the  same  lead 
screen  is  placed  near  the  radium  5(>  cm.  away  from  the  electroscope. 
Florance1  has  measured  the  quantity  of  gamma  rays  emerging  from  a 
sheet  of  lead  through  which  primary  gamma  ray-  emerge,  but  in  a  di- 
rection from  which  the  original  ravs  an1  excluded  by  heavy  masses  of 
lead.  Studying  the  properties  of  these  secondary  rays,  he  has  come  to 
the  conclusion  that  they  are  simply  diffused  primary  gamma  rays.  They 
may  be  compared,  therefore,  to  the  rays  of  white  light  which  pass  in  every 
direction  from  t  he  further  side  of  a  sheet  of  paper  held  up  before  a  light. 

Secondary  gamma  rays  produced  by  beta  rays  have  been  demon- 
strated especially  by  ,1.  A.  (Iray.- 

Delta  Rays.  These  are  produced  by  any  source  of  alpha  rays,  and 
are,  at  least  in  part,  secondary  radiations  caused  by  t  he  bombardment  of 
the  substance  itself  by  the  alpha  particles.  They  are  slowly  traveling 
elect  1 1  in- 
Luminous  Effects  of  Radium  Rays. — .Many  substances  are  fluor- 
•  under  the  influence  of  these  ray.-  and  become  visibly  luminous  in 
lontr  as  t  hev  are  held  verv  near  t  he  radium.  Salts  ot  barium 
All  but  the  purest  and  must  expensive; 
•  admixture  of  barium  salts  and  hence  are 
Jadium  in  a  very  weak  mixture  with  barium 
•tivelv  when  heated.  Pure  radium  bromid  i- 
c.  A  diamond  held  near  a  specimen  of  radium 
nous,  and  tlii-  property  sometime-  distinguishes 
illations.  Deviation  of  the  beta  rays  by  a  magnetic 

'.tin. 


KADI  I'M  1255 

field  enables  one  to  obtain  distinct  radiumgraphs  by  the  gamma  rays 
alone,  the  object  being  beyond  the  carrying  distance  of  the  alpha  rays. 
A  longer  time,  of  course,  is  required. 

A  part  of  the  disturbing  beta  rays  is  absorbed  by  zinc  sulphid,  and 
clearer  pictures  may  be  obtained  by  mixing  the  radium  salt  with  a 
certain  percentage  of  this  substance. 

Radiumgraphs  of  small  animals  do  not  show  the  bones,  since  the 
bones  and  flesh  are  about  equally  resistant  to  the  penetrating  rays. 

Influence  of  the  Thickness  of  the  Layer  of  Radium. — The  amount 
of  radiation  is  greater  from  a  moderately  thick  layer  of  a  radium  salt 
than  from  a  very  thin  one.  The  alpha  rays  practically  all  radiate  from 
the  surface.  Those  from  the  deeper  layers  are  mostly  absorbed  by  the 
superficial  layers.  The  beta  rays  penetrate  more  abundantly  from  the 
deeper  layers  and  it  is  owing  to  them  that  a  thick  layer  of  radium  is 
somewhat  more  effective  than  a  very  thin  one.  A  layer  of  radium 
0.4  mm.  thick  gives  out  only  about  one-quarter  as  much  radiation  as  a 
layer  2  mm.  thick.  The  percentage1  of  beta  rays  is  almost  twice  as  great 
in  the  latter  case. 

Radium  Rays  Lessen  the  Resistance  of  Selenium  Cell. — This  effect 
is  produced  more  slowly  than  by  ordinary  light  or  by  the  .r-ray. 

CHEMIC  EFFECTS  OF  RADIUM  RAYS 

Barium  platinocyanid  is  gradually  changed  from  its  original  apple- 
green  color  to  a  brownish  yellow,  and  this  is  accompanied  by  a  lessened 
degree-  of  fluorescence,  just  as  in  the  case  of  exposure  to  the  x-ray.  The 
Sabouraud  and  Noire  pastils  for  the  dosage  of  the  .r-ray  are  slowly 
discolored  by  radium  rays.  A  similar  effect  is  produced  upon  the  test 
objects  in  the  Holzknecht  chromoradiometer,  and  these  are  of  practical 
use  in  standardizing  the  therapeutic  dosage  of  radium  radiation. 

The  impact  of  radium  rays  causes  a  number  of  chemic  changes 
which  ordinarily  require  some  outside  influence,  such  as  a  high  tempera- 
tun-.  \Yater  is  decomposed  into  oxygen  and  hydrogen.  Ozone  is 
produced  from  the  oxygen  of  the  air.  Oxygen  and  hydrogen  or  oxygen 
and  nitrogen  enter  into  combination.  The  alpha  rays  are  much  more 
absorbable  and  are  also  much  more  active  chemically  than  the  beta  and 
gamma  rays.  Hut  in  most  experiments  the  alpha  rays  are  arrested  by 
the  walls  of  the  container.  The  effect  is  like  the  catalysis,  by  which  we 
used  to  believe  that  a  substance  exerted  a  chemic  action  by  its  inert' 
presence  without  undergoing  any  modification  itself. 

The  penetrating  rays  of  radium  cause  decomposition  of  sodium  iodid. 
and  Kailan  has  found'  that  a  solution  of  Mich  a  substance  in  water  which 
contains  the  ordinary  amount  of  oxygen  absorbed  from  the  air  is  much 
more  rapidly  decomposed  than  when  the  water  has  been  boiled  to  free 
it  from  oxygen. 

Radium  decomposes  lecithin  and  fatty  acids,  and  its  effect  upon  the 
embryonic  cells  and  upon  leukocyte-  and  upon  tumor  cells,  all  of  which 
are  rich  in  lecithin,  is  partly  at  least  due  to  the  decomposition  of  this  sub- 
stance.- 

The  t'tnuncition  from  rntl/nm  decomposes  uric  acid  and  other  purms. 

'Sii/h.  Akud.  Wiss.  Wcin.,  1  •_'<>.  I'.Ul. 
2  P.  Mi'xTiiitskv.  Kmisskv,  Vratcli  i\.   rJ: 


12.>l>  MF.Dle  AL    KLKCTHICITY    AND    KONTCEX     KAYS 

and  produces  much  more  soluble  substances.  Mesernitsky1  finds  that 
.029  gram  of  sodium  monourate  is  completely  decomposed  in  twelve 
days  by  50  millicuries  of  emanation. 

The  glass  tube  in  which  a  specimen  of  radium  is  kept  fora  longtime 
becomes  somewhat  browned  by  a  molecular  change1. 

The  Spinthariscope.-  Crookes  has  devised  a  little  instrument,  con- 
sisting of  a  closed  metal  cylinder  with  a  barium  platinocvanid  screen 
inside1  at  one  enel  and  a  magnifying  lens  at  the  other  end.  A  small 
particle  of  radium  is  placed  at  the  back  of  a  metal  disk  fastened  a  short 
distance1  in  front  of  the  fluorescent  screen.  Hays  from  the  radium 
cause1  brilliant  fluorescence  in  the  scree1!!.  This  light  is  seen  to  consist 
of  thousands  of  scintillating  sparks,  showing  the1  impact  of  successive 
alpha  and  beta  particles  upon  the  different  crystalline  particles  of  the 
screen. 

fluorescent  substances  exposed  to  the  emanation  from  radium 
become'  luminous.  Solutions  e>f  radium-bearing  salts  are  luminous. 

RADIOGRAPHIC  EFFECT  OF  RADIUM  RAYS 

All  kinds  of  radium  rays  produce  an  effect  upon  a  sensitized  plate. 
One  must  enclose'  the  radium  or  the1  photographic  plate  in  se)ine 
light-proof  e-nvelope  in  order  to  secure  the1  effect  of  the1  radiation  apart 
from  that  of  ordinary  light  from  the  fluorescent  radium  salt.  The 
ravs  will  pass  through  substances  opaejue  to  ordinary  light  and  produce 
radiographs,  such  as  one'  of  a  coin  and  a  key  inside1  of  a  leather  purse. 
Raeliumgraphs  are1  less  sharply  defined  than  picture's  by  means  of  an 
.r-ray  tube  and  take1  a  very  much  longer  time.  A  fairly  gooel  radium- 
graph  of  a  metallic  object  at  a  distance  of  10  cm.  may  be1  obtained  in  four 
hours  with  six  seale'd  glass  tubes  of  phosphorescent  zinc  sulphid  and 
barium  and  radium  chloriel,  activity  1000.  The  plate'  in  this  experi- 
ment is  enclosed  in  five  thicknesses  of  black  paper.  Specimens  of  greater 
radio-activity  produce'  radiumgraphs  in  a  somewhat  shorter  time — one 
hour  at  a  distane-e1  of  20  cm.  or  one  day  at  a  distance  erf  1  meter.  A  pure1 
radium  salt  of  2,000.000  activity  and  20  mg.  produces  a  good  radiogram 
in  one  or  two  seconds  when  in  e-ontact  with  the'  black  paper  em-losing 
the  film. 

All  the-  rays  from  radium  affect  a  photographic  film,  anel  this  effect 
may  be  used  as  a  measure  of  the  activity  of  the  substance.  Two  speci- 
mens, examined  under  the  same,  conditions  as  to  distribution  over  the1 
surface  of  the  applicator,  as  to  the  nature  and  thickness  of  the'  material 
separating  the  radium  from  the  photographic  film  and  as  to  distance, 
-hould  produce  the  same  photographic  effect  in  the  same'  length  of  time 
it  1  hey  are  ot  t  he  same  strength ;  and  if  t  wo  specimen--  test  eel  under  t  he 
-ame  condition-  take  a  different  length  •!'  time  to  reproduce  an  e<|iial 
photographic  etled.  we  may  know  that  their  radio-activities  varv  in- 
,  '-r-e!y  as  I  he  I  hues  required. 

ivs,    like   ordinarv   c;iihode   lays,    give   rise   to   abundant 
in  passing  t  h rough  a  solid  subst  ane-e,  and  t  hese  a  re  widely 
is  i  he  cause  of  the  lack  of  e  list  inct  ne-s  m   ra<  liunigra]  >hs. 
radium  themselves  lo-e  somewhat   of  their  pure  \\hite- 
•-e  of  time,  tin.-  prohablv  being  due  lo  all  effect   upon  the 
I  ifi  'sent  as  an  m  i  punt  v. 

:  [,c  H;niiuiii,  '.i.   I,  April,  l!>r_'.  1  \~>. 


RADIUM  1257 

THE  THEORY  OF   RADIO-ACTIVITY 

The  radium  atom  uniformly  generates  energy  in  some  way  which  wo 
can  only  guess  at,  and  this  energy  is  manifested  in  1  wo  wavs — one, 
by  radiation  of  rays,  both  charged  and  uncharged  with  electricity;  and 
second,  by  conduction,  /.  r.,  gradual  transmission  to  surrounding 
bodies  in  a  gaseous  or  liquid  medium  by  the  production  of  an  emanation 
and  induced  radio-activity. 

Alpha  rays  are  charged  with  positive  electricity. 

Beta  rays  are  cathode  or  negative1  particles  freed  from  the  radium  by 
the  loss  of  the  positively  charged  alpha  particles. 

The  beta  rays  give  origin  by  their  friction  with  the  radium  atoms 
to  gamma  rays,  which  are  similar  to  the  most  penetrating  kind  of  .r-rays. 

The  portion  of  a  radium  atom  which  remains  after  the  emission 
of  the  alpha  and  beta  particles  is  transformed  into  the  gas  known  as 
the  emanation. 

The  emanation  itself  gives  rise  to  induced  alpha,  beta,  and  gamma 
rays,  and  what  remains  is  partly  helium  gas,  which  is  a  stable  substance 
giving  rise  to  no  further  phenomena,  and  partly  a  solid  substance 
(radium  A),  which  causes  induced  radio-activity  and  is  transformed 
into  radium  B.  Successive  transformations  finally  result  in  radium  F, 
which  is  the  same  as  polonium,  and  a  final  stage  results  in  the  production 
of  lead.  Thorium  undergoes  similar  transformations,  the  final  stage  of 
which  is  bismuth. 

PHYSIOLOGIC  EFFECTS  OF  RADIUM 

The  radiation  from  a  sealed  glass  tube  containing  0.2  gram  of  radium 
of  SOO.OOO  activity  carried  in  the  pocket  of  a  flannel  shirt  for  six  hours 
produced  an  ulcer  without  any  pain  and  which  took  over  a  month  to  heal. 
This  had  been  preceded  by  an  erythema  which  developed  after  a  fifteen- 
day  period  of  incubation.  This  accident  was  a  personal  experience  of 
Becquerel.  An  accident  of  the  same  nature  occurred  to  Mine.  Curie; 
and  M.  Curie,  Dr.  Oudin.  and  M.  (iiesel  have  made  experiments  upon 
themselves  and  upon  animals. 

Ten  hours'  contact  with  radium  of  5000  activity  in  a  gutta-percha 
sac  caused  an  erythema,  followed  in  twenty  days  by  ulceration  taking 
four  months  to  heal. 

Two  hours'  contact  \vith0.3gram  of  pure  radium  bromid,  contained 
in  thin  celluloid,  caused  ervthema  and  dermatitis  with  a  raw  weeping 
surface  like  that  following  a  burn.  Complete  healing  took  three  months 
and  left  a  smooth  cicatrix  like  that  from  a  burn. 

Plate  15  shows  the  result  of  an  experiment  upon  my  own  forearm 
with  my  radium  applicator  No.  1.  a  sealed  glass  tube  containing  about 
20  nig.  <>f  radium  of  an  activity  of  about  2.000.000.  One  minute  pro- 
duced no  vi.-ible  effect:  two.  three,  four,  and  five  minutes  produced 
a  more  and  more  pronounced  redness  and  itching  with  some  desquama- 
tion.but  no  blistering  or  ulceration.  Thi-  reaction  was  preceded  by  a 
period  of  incub;iiion  la-ting  about  two  weeks. 

The  -a me  powerful  tube  of  radium  enclosed  in  an  aluminum  treat- 
ment t  u be.  !  mm.  t  hick  and  covered  wit  h  rubber,  produces  a  dry  redne-- 
in  fifteen  minute-  and  bli-teriiiLi  in  twenty-five  or  thirty  minute-,  as  in 
the  treatment  of  keloid. 

\Yorking  in  the  extraction  and  testing  of  radium  exposes  one'.-  hands 


12~>S  MEDICAL    ELECTRH  ITY    AND    HONTC.EX    RAYS 

to  the  radiation  and  sometimes  causes  dermatitis  of  the  fingers  like  that 
from  which  .r-ray  workers  suffer. 

Paul  Besson1  has  suffered  from  slight  bad  effects  after  studying 
specimens  of  radium  for  a  number  of  hours.  After  a  week's  incubation 
an  attack  of  rhinitis  developed  with  considerable  pain,  discharge,  and 
desquamation. 

He  classifies  the  methods  of  applying  radium  by  which  the  skin  may 
be  affected  as  follows: 

A  Single  Strong  Application. — This  may  be  with  a  specimen 
of  great  radio-activity  left  on  the  surface  for  a  few  hours  or  one  of  less 
activity  for  many  hours.  The  result  is  an  acute  radiodermatitis. 

Strong  but  Divided  Applications. — A  high  degree  of  radio-activity 
applied  for  a  few  minutes  each  day  produces  a  slightly  milder  inflam- 
matory and  ulcerative  effect  than  the  same  length  of  application  at  a 
single  session. 

Long  and  Weak  Applications. — This  method  uses  very  weak 
radio-activities  applied  for  a  long  time.  Besson  says  that  it  does  not  lead 
to  accidental  ulceration,  and  he  believes  that  it  will  be  the  method 
adopted  in  the  future. 

Pissareff's  classification  of  the  dcyrccs  of  radiodermatitis  from  ap- 
plications of  radium  is  quoted  by  Besson  as  follows: 

Firxt  Dctjrec. — There  is  a  period  of  incubation  lasting  two  or  three 
weeks.  Then  the  hairs  become1  brittle  and  fall  out.  The  skin  is  left 
perfectly  smooth  and  may  be  slightly  pigmented.  The  hair  be'gins  to 
grow  again  in  two  months  and  the  skin  regains  its  normal  appearance. 

S<  com/  l)«jr<c. — This  is  characterized  by  an  e.Tythema,  pink  at  first, 
but  later  of  a  darker  red.  The  tissues  are  infiltrated  and  the.- re  is  some 
desquamation,  but  no  ulceration.  The  epidermis  is  left  a  little  thin 
and  diiny,  and  this  some'times  remains  for  a  long  time. 

Third  Dcfjrtc. — There  is  an  intense  dark  red  erythema.  The  skin  is 
thickened,  and  blisters  form  which  exude  se'rum  and  afterward  pus. 
.Some  ulceration  ensues  which  is  sometimes  quite  painful.  The  hair- 
follicles  are  completely  destroyed  and  the?  cicatrix  is  permanently  pig- 
mented. 

/''on lift  I)njr(c. — There  is  complete  destruction  of  the  skin  with  pain, 
which  is  often  very  severe  and  may  radiate1  to  a  distance.     A  brown 
.-louiili    forms    and    there    is   a  thick  discharge.      The   slough  doe-s   not 
separate  ea~ilv  and   the  ulcer  is  a  deep  one,  which  is  very  tedious  in 
healing.      The  cicatrix  has  nodular  borders  and  it  is  ele'pivssed  anel  pig- 
There  is  usually  a  pe>rienl  of  incubation  e>f  from  eight  to  twenty-ono 
'lays  after  the  application  of  radium.      '1  he  more  sensitive  the1  skin  the 
susceptible  it    is  to  radium,  and  diseased  areas  react  much  more 
t  '.an  t  he  -ound  -kin. 


EFFECT    ON   MICRO-ORGANISMS 

'ericidal   effect   is   probablv   due   to   the   alpha  rays  alone, 
-hown    to  act  upon   culture's  ///   ritro  by  Pfeif'fer  and  Frcid- 
hoid    fever    and    cholera);    bv     Hoffmann     (staphvlococcus 
.  .     Campari   has  shown   its  efficiency  upon  tubercle  bacilli 
thi    anterior  chamber  of  the  e've1  and  upon  diphtheria 
.:     <  •  ;.    |{:nli«i-activitc.  ('.aiithicr-Villars,  Paris.  1004. 


RADIUM  1259 

bacilli  introduced  into  the  muscles.      Injections  of  radio-active  .solutions 
prevented  the  infection  of  the  animal  by  these  inoculations. 

The  alpha  rays  have  so  little  penetration  that  it  may  easily  happen 
that  only  the  bacteria  in  the  superficial  layers  of  the  culture  arc  de- 
stroyed, and  that  the  deeper  layers  of  a  culture  in  a  test-tube  are  not 
affected  by  the  radiation  from  radium. 

Infiltrating  the  culture  with  the  emanation  from  radium  would  in- 
duce the  liberation  of  alpha  rays,  as  well  as  others  in  the  substance 
itself,  and  should  destroy  bacteria  throughout  the  culture. 

\Vcrner  has  shown  that  in  cases  of  radiodermatitis  the  affected  tis- 
sues are  not  susceptible  to  bacterial  inoculation,  and  this  may  be  due  to 
induced  radio-activity  in  the  tissues. 

Braunstein  finds  that  bacteria  cannot  develop  in  air  laden  with 
radium  emanation. 

(Joldberg  finds  that  typhoid,  anthrax,  and  colon  bacilli  are  destroyed 
by  the  gaseous  emanation. 

Dorn,  Bauman,  Valentiner.  Kidman,  and  a  number  of  others  have 
found  that  radium  rays  and  radium  emanation  are  bactericidal. 

The  minimum  exposure  to  radium  emanation  required  to  markedly 
affect  and  also  to  kill  cultures  of  Bacillus  prodigiosus  have  been  studied 
by  Jansen.1 

Radiations  Tested  in  Experimental  Tuberculosis  of  the  Eye. — Radium 
and  mesothorium  radiations  do  not  kill  the  bacilli,  though  they  do  have 
some  attenuating  effect.  They  have  an  effect  on  the  tissues,  chiefly  the 
blood-vessels.  Ultraviolet  rays  have  verv  much  more  effect  on  the 
bacilli.'-' 

Among  the  earliest  observations  are  those  of  Askinass  and  Caspari, 
verified  by  Danysz.3  A  culture  of  Micrococcus  prodigiosus  upon  agar- 
agar  was  not  affected  in  one  experiment  by  exposure  to  the  radiation 
from  a  distance  of  1  cm.  and  through  a  sheet  of  aluminum  0.10  mm. 
thick.  The  same  radium  salt,  activity  not  stated,  completely  arrested 
the  development  of  a  culture  with  which  it  was  directly  in  contact  for 
from  two  to  four  hours.  Cultures  of  anthrax  have  been  destroyed  in 
the  same  way  (Danysz).  The  latter  author  and  Besson  believe  that  the 
radio-activity  induced  in  the  culture  by  the  emanation  from  the  radium 
as  well  as  the  direct  radium  rays  were  operative  in  this  case. 

The  beneficial  effect  from  radium  applications  in  bacterial  diseases — 
e.  (/.,  those1  observed  by  Tizzoni  and  Bongiovanni — in  hydrophobia  can- 
not be  attributed  to  a  direct  bactericidal  effect,  because  the  tissues  of 
the  patient  would  be  destroyed  by  any  radium  application  powerful 
enough  to  arrest  the  development  of  bacteria  in  them. 

The  effect  of  radium  upon  infective  micro-organisms  and  infection  of 
the  tissues  has  been  studied  by  R.  Warner.'  Two  principal  results  follow 
from  his  researches:  First,  radium  rays  may  destroy  bacteria  in  certain 
cases,  and  in  others  modify  them  without  developing  in  them  properties 
Favorable  to  immunization;  >econd.  the  tissue  cells  which  are  destroyed 
by  these  rays  are  capable  of  pi'oducinir  bactericidal  substances  which  are 
scarcely  observed  in  ordinary  autolytic  proce-ses. 


fiir  Hyuirm'.  Ixvii.  1  :!."">.  I'.MO. 
-  Flt'inrniims  an.l  Krusins.  IVut.  M.-,l.  \Yorh.,  August  ol.  I'.tll,  KM). 
:  D:in\->z  (I'astrur  In-titii!c  .  C'mnpti's  llcndc-;.  l'rh.  Iti.  I'.Xi:',. 
4  MiinVh.  Mc-1.  \Vnch..  p.  It'rJ.").  A'm.  _'-'.  I'.td."). 


1200  MKDH  AL  Ki.F.eTHHTry  AND  KONTOK.X   KAYS 

EFFECT   ON    PLANTS 

This  varies  according  to  the  conditions  of  the  experiment.  Lilac 
and  chestnut  buds  are  hastened  in  their  development  by  exposure  to 
radium  or  radium  emanation  in  November  or  December,  but  no  per- 
ceptible effect  occurs  with  an  earlier  or  a  later  exposure.1 

l>i  lit  /v///.s-  from  ratl/iini  retard  the  germination  of  different  grains  in 
proportion  to  the  penetrability  of  their  outer  layer  and  not  to  their 
chemic  composit  ion.- 

Radium  emanations  greatly  increase  the  growth  and  chlorophyl  con- 
tent in  seeds  and  plants.  • 

EFFECT   OF   RADIUM   ON   TOXINS 

Sulphate  of  radium.  20  micrograms  per  20  c.c..  left  more  than  thirty 
days  in  contact  with  Ostrovsky's  necrotuberculin  reduces  its  activity. 
Tetanu-  antitoxin  was  unchanged  and  diphtheria  toxin  and  Koch's 
bacilli  were  only  slightly  attenuated.1 

EFFECT    OF    RADIUM    UPON    ANIMALS 

The  radiation  destroys  infusoria,  the  larva'  of  insects,  and  the  eggs 
of  1  lirds. 

Animal  ferments,  such  as  pepsin  and  pancreatin.  according  to  Bergell 
and  Braunstein,  have  their  activity  somewhat  increased,  but,  according 
to  Ivichet,  lactic  fermentation  is  retarded. 

The  venom  of  snakes  (cobra  and  viper)  is  destroyed  by  the  radiation 
or  the  emanation  from  radium.  That  of  the  land  salamander  and  the 
common  toad  is  not  destroyed.5 

Emanations  of  radium  do  not  affect  the  gaseous  respiratory  ex- 
changes, the  oxygen  in  the  arterial  and  venous  blood  remain  normal. 
The  blood-pressure  is  lowered  by  a  vasomotor  effect." 

Small  animals  which  have  died  afier  exposure  to  radium  show  con- 
gestion of  the  spinal  cord  and  its  membranes  with  submeningeal  hem- 
orrhages. 

<  >ne  effect  upon  the  eye  is  an  atrophic  retimtis  without,  change  in 
the  cornea  or  the  other  ocular  media. 

There  are  different  degrees  of  susceptibility.  The  same  application 
which  causes  ulceration  in  a  guinea-pig  will  only  stimulate  the  growth 
of  hair  in  a  rabbit. 

])aiivs/  found  that  moderate  applications  in  the  case  of  a  mouse 
produced  erythema,  with  loss  of  hair  and  a  discharging  surface,  but  no 
general  ills!  url  ia  nee. 

b  .posim;  to  radium  of  vi  ry  great  activity  caused  convulsions,  paral- 

1   .   and  death   in  about    ten   days  without   surface  lesions.      The  fatal 

-  are  produced  bv  the  gamma   rays  and  by  the  most    penetrating 

'   of  !  he  be  i  a  fa  vs.      Tlii-  effect   is  analogous  to  that  of  t  he  X-ray. 

•      I  nei    nus  system  in  thesmallest  animals  is  covered  by  only 
•    transparent    bones   and    soft    tissues,  through  which 
•  \  -  ma  v  act . 


UADIl'M  1201 

In  the  human  being,  on  the  contrary,  these  vital  organs  are  protected 
by  tissues,  through  which  practically  none  of  the  physiologically  active 
ravs  of  radium  can  penetrate.  .None  of  the  resulting  nervous  symp- 
toms occur  in  man  from  radium  applications,  although  they  arc  not  so 
very  unusual  from  exposure  to  the  radiation  from  an  ./'-ray  tube. 

Young  animals  arc  much  more  susceptible  to  the  fatal  effect  of 
radium  applicat  ions. 

lleinecke  has  found  the  wall  of  the  intestines  in  small  animals  de- 
stroyed through  the  intact  abdominal  wall.  The  lymphatic  glands, 
the  spleen,  and  the  thymus  gland  atrophy  after  exposures  which  do 
not  injure1  the  skin,  lleinecke  and  Selden  find  that  radium  has  an 
effect  like  the  .r-ray  in  producing  sterility  in  men  and  women  as  well  as  in 
animals. 

Ten  or  fifteen  minute.-'  application  of  very  active  radium  is  followed 
by  development  of  an  acute  eryi  hema  in  1  \\cnty-fotir  or  forty-eight  hours. 
No  experiments  have  yet  been  made  with  the  alpha  or  beta  rays  sepa- 
rately to  ascertain  their  physiologic  effect,  but  a  screen  of  sheet  lead  has 
been  used  in  applying  only  the  gamma  rays.  Such  a  therapeutic  appli- 
cation may  take  a  number  of  days. 

Pic/mentation  from  k<i<limn  Radiation. — One  milligram  of  radium 
bromid  applied  for  two  to  six  hours  to  the  shaved  skin  of  a  rabbit's 
ear  produces  an  area  of  decolori/ation  surrounded  by  a  pigmented  /one. 
The  pigment  is  deposited  in  the  depths  of  the  epithelial  layer  and  it  is 
not  deposited  when  an  albino  rabbit  is  used  for  this  experiment.1 

EFFECT  OF  RADIUM  UPON  THE  EYE 

It  causes  a  sensation  of  light  in  the  eye,  which  may  be  eluc  to  fluo- 
rescence of  some  of  the'ocular  media.  It  has  been  used  in  mild  applica- 
tions for  trachoma  and  other  lesion-.  The1  reported  cure  of  hydro- 
phobia in  rabbits  by  the  application  of  radium  to  the1  eye'2  is  very  curious 
and  is  important  enough  to  be  described  at  length. 

According  to  these  authors,  hydrophobia  virus,  which  has  been 
exposed  to  radium  emanation  for  from  four  to  thirty-six  hours,  changes 
to  a  powerful  antitoxin.  A  drop  of  this  injected  into  a  rabbit's  eye 
renders  the  animal  immune  to  subdural  inoculation  with  active  hydro- 
phobia virus.  Rabbits  already  inoculated  with  hydrophobia,  and 
presenting  a  rise  of  temperature  and  weakness  of  the  posterior  extremi- 
ties, we're  cured,  while  e'ontrol  animals,  which  we're  not  tivated,  got 
worse  and  died.. 

These  cases  were  treated  by  the  application  of  radium  etf  100,000 
activity  over  the-  brain  and  spinal  cord.  The  exposure.-  were  for  six  to 
twelve  hours  the  first  day.  live1  to  twelve  hours  the  second  day,  and  four 
hour-  on  each  of  the  six  following  days. 

Birch-iiirschfeld3  has  left  L'O  nig.  of  radium  bromid  in  a  mica  en- 
velope upon  the  closed  eyelid  of  a  rabbit  for  two  to  six  hours.  Only 
the  beta  and  gamma  rays  could  penetrate1  to  the  eye  itself.  There  was 
a  period  of  incubation  la>iing  seven  to  sixteen  days,  follower!  by  con- 
junctivitis, iritis.  a;id  superficial  or  interstitial  keiatitis  (inflammation 
of  the  come_a).  There  was  inflammation  of  the  e-yelid  with  loss  of  hair 

1  .1.  (  >.  \V.  Barratt.  Quarterly  Journal  of  Kxperimental  Physiology,  11 1.  2t'>l,  19K>. 
-  Ti/xoni  and  Boiifiiovanin.   Rii'orma  Medira,  July.  190."),  p.  sis. 
"'  Aivhiv.  f.  Ophthalmologir.  vol.  lix.  pp.  L's7  -:ji)ti;  reviewed  in  l,e  Uadium.  Sept. 
15,  190."). 


12(12  MKDICAL    KLKCTHICITV    AND    K(")NT(  iK\     HAYS 

and  ulceration.  There  was  often  atrophy  of  the  optic  nerve, 
•walls  of  the  blood-vessels  were  hut  slightly  affected.  The  retina  was 
decidedly  affected  and  in  the  same  way  as  by  the  x-ray,  not  as  by  the 
ultraviolet  ray.  The  lesion  was  a  degenerative  one,  chiefly  of  the 
ganglionic  cells.  The  optic  nerve  atrophy  was  secondary  to  this. 
There  was  no  inflammatory  change  in  the  retina  or  optic  nerve. 

Subjective  troubles  with  the  eyes  have  been  noted  after  studying 
specimens  of  radium  for  too  long  a  time.  The  eyeball  should  he  pro- 
tected by  heavy  metal  or  lead-glass  shields  when  radium  is  applied  to 
the  eyelids  in  therapeutics. 

Wichmann1  has  made  experiments  upon  the  absorption  of  radium 
by  the  skin  and  other  tissues.  The  normal  skin  arrests  two-thirds  of  the 
radiation,  most  of  this  being  absorbed  by  the  derma  and  very  little  by 
the  epidermis  and  the  subcutaneous  fat.  Abnormal  tissues  in  general, 
such  as  lupus,  cancer  of  the  breast,  and  fibromyoma  of  the  uterus,  ab- 
sorb from  50  to  100  per  cent,  more  than  adjacent  healthy  tissues. 
This  may  very  probably  be  the  cause  of  an  apparently  selective  action 
of  the  rays  upon  morbid  tissues.  The  greater  part  of  the  rays  being 
quite  absorbable,  a  special  arrangement  of  metal  or  other  screens  is 
required  to  produce  an  effect  upon  the  deep  tissues  without  undue 
action  upon  the  skin.  The  screen  is  to  arrest  the  absorbable  rays  while 
permitting  the  passage  of  the  highly  penetrating  rays.  Wichmann's 
experiments,  including  l.'i  microscopic  examinations,  do  not  confirm  the 
usual  statement  that  there  is  a  primary  effect  upon  the  inner  walls  of 
the  blood-vessels. 

.1.  Sehlacta2  has  experimentally  studied  the  similarity  previously 
reported  by  Werner  between  the  effect  from  inlradermal  injections  of 
lecithin  and  that  from  exposure  to  the  radium  rays  or  the  x-ray.  The 
conclusion  may  be  drawn  from  his  experiments  thai,  while  these  in- 
jections will  cause  alopecia  and  ulceration  just  like  that  from  the 
radiation,  we  do  not.  yet  know  the  precise  nature  of  the  chemic  products 
generated  in  the  tissues  by  the  radiation. 

EFFECT  UPON  ANIMALS    DURING   THE   STAGE    OF  DEVELOPMENT    AND 

GROWTH 

Tissues  or  organisms  of  slow  growth  appear  to  have  their  growth 
retarded  by  exposure  to  radium  rays,  while  those  of  rapid  development 
are  either  destroyed  or  the  growth  is  slowed  or  quickened,  according 

to  the  nature  of  the  different  tissues. 

PATHOLOGIC  EFFECTS  OF  RADIUM 

The  change-  in  the  skin  appear  to  be  analogous  to  those  resulting 
from  the  ./"-ray;  they  require  a  longer  application,  bul  are  more  intense. 

Slow  degenerative  change-  take  place  in  the  cellular  elements  of 
tl  in.  e.-pecially  t  he  cells  of  the  epidermis,  and.  to  a  less  extent ,  the 

cell-  ni  the  glands,  blood-vessels,  and  muscle.-.  (  onnective  tissue  is  not 

SO  HIM 

rj  here  i«  a  secondary  congestion  and  extravasation  of  serum  and 
Jeukocyti  .  The  legion-  in  the  blood-vessels  are  chiefly  responsible  for 
the  verv  -low  healing  when  ulceration  occurs. 


RADIUM 

THERAPEUTIC  USES  OF  RADIUM 

1.  The  mildest  applications  modify  the  nutrition  of  the  tissues  and 
stimulate  the  growth  of  hair  and  the  activity  of  the  glandular  elements. 
They  may  be  useful  in  cases  of  atrophy,  atony,  or  ulcers  of  the  skin,  and 
in  ophthalmologic  and  gynecologic  cases. 

2.  A  more  or  less  destructive  effect  may  be  produced  upon  such 
affections  as  epithelioma,   lupus,  nevus  (birth-mark),  verruca   (wart), 
keloid,  and  a  variety  of  other  localized  conditions. 

Administered  internally,  solutions  of  radium  modify  morbid  condi- 
tions of  the  Castro-intestinal  canal  and  other  viscera  and  produce  a 
systemic  effect.  The  latter  may  act  as  an  adjunct  to  other  medication. 

Inhalations  of  air  laden  with  the  emanation  from  radium  have 
been  used  for  an  effect  upon  tubercular  processes  in  the  lungs  and 
air-passages. 

APPARATUS    FOR   THERAPEUTIC    USE    OF   RADIUM 

There  are  two  forms  of  apparatus  for  applying  the  radiation  from 
radium.  In  one  the  radium  is  placed  in  a  shallow  cavity  and  covered 
by  a  very  thin  screen  of  gutta-percha,  aluminum,  celluloid,  or  mica. 
In  the  other  the  radium  is  mixed  with  a  suitable  waterproof  varnish  and 
fixed  upon  the  surface  of  the  instrument.  The  latter  method  has  many 
advantages. 

Danne's  varnish  transmits  GO  per  cent,  of  the  radiation,  while  the 
thinnest  kind  of  a  screen  transmits  only  10  per  cent,  of  the  radiation, 
and  even  this  does  not  include  the  alpha  rays. 

Radium  Applicator  with  a.  Screen. —  Fig.  851  shows  the  usual  type 
of  apparatus.  The  shallow  cavity  is  either  5,  10,  or  15  mm.  in  diameter, 


A 

Fig.  NJ!.  —Radium  applicators:   .1,  A'-rudium  cell  covered  by  mica;  H,  radium  applicator 

to  fit  on  a  rod. 

and  is  said  to  be  filled  with  either  0.01,  0.05,  or  0.1  gram  of  radium. 
The  activity  of  the  latter  may  be  from  50.000  to  l.XOO, 000,  the  cost  of 
the  instrument  and  radium  varying  accordingly  from  825  to  $S(JOO. 

The  higher  activities  require  only  a  few  minutes' application,  during 
which  the  patient  may  hold  the  instrument  in  position.  The  radium  is 
usually  held  in  contact  with  the  surface  to  be  treated,  separated  only  by 
the  thin  screen  of  the  apparatus.  As  it  is  difficult  to  thoroughly  dis- 
infect this  after  use,  a  better  plan  is  to  stretch  the  thinnest  kind  of  rub- 
ber, not  nearly  the  thickness  of  paper,  over  the  entire  instrument.  This 
rubber  may  be  renewed  each  time 

The  lower  activities  require  long  applications  and  the  instrument  had 
better  be  secured  in  position  by  adhesive  plaster. 

Apparatus  with  Radium  Secured  by  Varnish.-  One  type  of  in- 
strument is  shown  in  Fig.  S51.  The  surface  of  a  metal  disk  is  from 
10  to  25  nun.  in  diameter,  and  is  coated  with  varnish  containing  from 
0.01  to  ().()()  gin.  of  radium  of  from  50.000  to  l.SOO.OOO  activity!  The 
instrument  and  the  radium  cost  from  825  to  85000.  A  little  tube  at  the 


1204  MKD1CAL    KLKCTHICITV    AND    KONTGEN    KAYS 

back  of  the  disk  serves  to  receive  a  rod  acting  as  a  handle  or  a  cord  by 
which  the  disk  may  be  bound  in  position.  The  radium-coated  surface 
i-  UMially  placed  directly  in  contact  with  the  part  to  be  treated.  It 


disinfected  after  use  by  washing  in  vottr.  or  1  per  cent,  solution 
xxi am  pernuuujanatc:  or  hydrogen  peroxid,  or  /  per  cent,  sodium 
iti  or  (ili/ciri/t.  or  /  fier  cent,  tncrcurij  b/chh>r/(l.  Exposure  to 
foi'inaldehyd  fumes  is  an  excellent  method.  Boiling 
in  water  for  a  few  minutes  does  no  harm,  but  alcohol 
and  (the)'  are  to  be  avoided. 

An  ulcerated  surface,  whether  malignant  or  not, 
had  better  be  covered  with  aluminum  foil.  - ,,',-,-,  or 
T|ju  nun.  thick.  This  protect >  the  instrument  from 
contamination  and  arrests  only  an  insignificant  part 
of  t  he  radial  ion. 

Other  instruments  are  like  those  shown  in  Fig. 
So2.  where  the  radium  is  varnished  upon  a  thin 
piece  of  metal  attached  to  a  long  stem  with  a  joint, 
by  means  of  which  it  may  be  adjusted  in  any  posi- 
tion. Tln>  may  be  applied  not  only  upon  the  sur- 
face of  the  body  but  also  to  many  of  the  mucous 
meml  >ranes. 

Others  are  metal  cylinders  coated  with  radium- 
varnish.  These  may  be  straight,  curved,  flexible, 
oi'  jointed,  for  application  to  the  eye.  ear.  nose, 
throat,  urethra,  or  uterus. 

Narrow  strips  of  celluloid  varnished  with  radium 
mav  be  introduced  into  punctured  wounds  made  in 
the  substance  of  a  malignant  tumor. 

Radium-coated  celluloid  in  flat  surfaces  or  as 
bougies  '  Fig.  S"v> )  are  chiefly  employed  by  the 
aut  hoi1. 

Radium-coated  Cloth.-  This  is  fastened  upon 
the  surface  to  be  treated  in  cases  requiring  a  long 
application.  It  contain.-  0.0'J  .mil.  ot  radium  per 
xpiare  centimeter  and  of  a  radio-activity  varying 
from  .")()(»  to  10.000.  It  costs  from  si  to  S.I1  per 
>(|Uai'e  centimeter.  1  he  surface  is  varnished  and 
the  cloth  mav  be  used  any  number  of  times. 

(  Ila>-  lubes  containing  radium  are  unsatisfac- 
tory for  therapeutic  purpo.-e.-.  The  glass  arrests 
a  very  large  proportion  of  the  rays  and  is  liable  to 
breakage. 

Protection  of  the  Neighboring  Skin.-  Sheet 
lead.  1  or 'J  mm.  thick,  may  be  used  when  the  ap- 
•  vere.  A  hole  of  the  proper  H/e  allows  the  rays  to 
I  he  diseased  area,  but  the  fact,  that  the  radium  is  at 
i~  to  'he  1  ime  of  exposure. 


RADH'M  1205 

Crusts,  scabs,  pus,  or  other  secretions  should  he  removed,  as  well  as 
hard  portions  of  epidermis.  They  would  all  tend  to  ahsorh  the  most 
active'  ravs  and  reduce1  the  therapeutic  effect  upon  tissue  cells. 

Longer  applica!  ions  may  he  made  upon  ulcerated  surfaces  than  upon 
unhroken  skin. 

THE    DOSAGE    OF    RADIUM    RADIATION 

The  quantity  of  a  radium  salt  should  he  1  or  2  eg.  per  square  centi- 
meter. The  duration  of  an  application  depends  upon  the  radio-activity 
and  whether  there  is  to  he  one  application  or  a  series  of  them.  It  must 
also  he  remembered  that  this  is  an  agent  of  which  some  specimens  sold 
for  therapeutic  use  may  not  prove  to  he  of  specified  radio-activity. 
The  dosage  given  below  is  intended  merely  as  a  general  guide,  to  he 
verified  by  cautious  trial  of  each  particular  specimen  of  radium.  Xo 
harm  at  all  and  only  a  trifling  delay  can  result  from  too  weak  applica- 
tions, while  very  great  suffering  may  follow  too  strong  ones. 

A  radio-activity  of  500,000  may  he  applied  for  an  hour  a  day  for 
six  or  eight  days  in  order  to  produce  a  superficial  destruction  and  an 
obliterating  effect  upon  the  blood-vessels  in  angeiomata. 

Weaker  specimens  would  have  to  he  applied  for  a  correspondingly 
greater  length  of  time  and  stronger  specimens  for  a  correspondingly 
shorter  time. 

The  intense  destruction  required  in  the  caseof  commencing  recurrence 
of  carcinoma  of  the  breast,  when  it  is  still  quite  localized,  ma}'  be  ob- 
tained by  the  application  of  radium  of  500.000  activity  for  an  hour  a  day 
for  twelve  or  sixteen  days.  The  same  effect  would  be  produced  by  the 
application  of  a  specimen  of  100. 000  radio-activity  for  two  or  three 
hours  a  dav  for  twentv  or  thirty  days;  or.  on  the  other  hand,  three  or 
tour  applications  of  six  to  ten  hours  each  with  an  activity  of  500,000 
will  produce  this  effect.  ' 

The  mildly  destructive  effect  required  in  lichen  planus  may  be  ob- 
tained by  applications  of  a  radio-activity  of  500.000  for  an  hour  each 
day  for  seven  days. 

Localized  scaly  prurigenous  eczema  is  favorably  modified  without 
destruction  of  tissue  by  500.000  radio-activity  for  two  minutes  three 
times  a  week,  or  100,000  radio-act  ivity  could  he  applied  once  for  half  an 
hour. 

Urethral  or  uterine  applications  of  an  activity  of  500.000,  lasting 
ten  minutes  and  repeated  three  or  four  times,  produce  an  alterative 
effect  without  destruction  of  tissue.  An  activity  of  100,000  would 
require  three  or  four  applications  of  half  an  hour  each. 

Applications  for  intercostal  and  other  neuralgias  and  for  herpes 
zoster  may  he  made  with  an  activity  of  500.000.  applied  for  ten  minutes 
at  a  time  tor  four  or  five  successive  days. 

Dosage  of  Radium  in  Medicinal  Substances  for  Internal  Ab- 
ministration.  —  Kach  irram  of  the  medicine  contains  a  measured  amount 
of  pure  radium  bromid,  varying  from  '•  to  10  micrognuns  fn,1IM,  ing.). 

Kadium   drinking-water  is  beneficial   in   trout   and  rheumatism  and 


Radium-bearing  quinin 
in  t  he  treatment   <  if  olist  in; 
tion  of  being  beneficial  in  internal  cancel 
SO 


1266  MEDICAL    ELECTRICITY    AND    RONTCJEN    RAYS 

A  pill  containing  radium  oven  in  this  very  small  amount  will  affect 
a  photographic  plate  if  left  directly  upon  it  for  twenty-four  hours. 

Other  medicines  to  which  radium  is  added  to  increase  their  special 
effect  as  well  as  for  its  own  properties  are  mercury,  arsenic,  digestive 
ferments,  sodium  nitrite,  and  various  medicinal  waters. 

Intravenous  Injection  of  Solution  of  Radium  Suit*.-  One  milligram 
of  radium  intravenously  causes  a  very  rapid  fall  of  blood-pressure  and 
death  in  a  few  hours,  ('ameron  has  noted  a  beneficial  effect  upon  the 
blood-pressure  and  blood-picture  from  a  single  intravenous  injection  of 
.")()  to  100  micrograms.  Ho  has  not  soon  much  effect  in  diabetes  or 
chronic  nephritis,  but  good  results  in  chronic  and  subacute  arthritis  and 
myelitis.  Three  weeks  after  an  intravenous  injection,  if  death  occurs, 
considerable  radium  may  still  be  found  in  the  bones  and  marrow. 

Dosage  of  Radium  in  Mixtures  for  External  Application. — Oleato  of 
mercury  and  mercurial  ointment  may  receive  an  admixture  of  1  micro- 
iiram  of  radium  per  gram.  This  is  said  to  enhance  the  specific  effect  of 
the  mercurial  inunctions  and  dressings. 

Radium  ointment  is  made  of  lanolin  or  vasolin.  or  a  mixture  of  both, 
and  contains  from  1  to  10  micrograms  of  radium  bromid  per  gram.  It 
has  been  used  in  carcinoma,  epithelioma,  and  for  rheumatic  pain. 

Radiferous  glycerin  is  made  by  actually  dissolving  the  radium 
bromid.  while  the  ointments  are  mechanical  mixtures  containing  solid 
particles  of  the  radium  salt.  The  emanation  is  given  out  very  much 
more  freely  by  radium  in  solution.  This  makes  the  solution  more 
effective  for  the  same  percentage  of  radium.  It  must,  of  course,  be  kept 
;n  a  seulod  crlass  container  when  not  in  use.  It  has  the  same  uses  as  the 
ointment,  and  is  especially  adapted  for  gynecologic  application.  It  con- 
tains trom  .,',,  to  10  micron-runts  of  radium  per  gram. 

Radiferous,  water  may  bo  prepared  of  any  strength,  from  in'oir  t° 
100  micron-rams  per  gram.  A  strength  of  from  \  to  10  micrograms  has 
been  used  as  an  injection  in  cancer  cases.  A  strength  of  ^  ,,'-(,,,  micro- 
ti'ram  per  gram  mav  be  used  as  a  beverage  and  is  more  radio-active  than 
the  majoritv  ot  natural  mineral  spring  waters. 

Radium-bearing  plain  water  or  mineral  water  preserves  indefinitely 
the  property  of  radio-activity,  which  in  the  natural  radio-active  spring 
Wat'-!'-  is  onlv  an  induced  and  vorv  temporary  quality. 

Baths  of  Radium-bearing  Water. — These  may  be  prepared  of 
greutor  st  rength  than  t  he  nat  ural  radio-act  ive  spring  waters  and  may  be 
Used  at  home  us  the  radio-act  ivit  v  is  permanent. 

The  Dosage  of  Radium  in  Terms  of  Holzknecht  ,r-Ray  Units. — 
K\  posing  a  1  lolxknechi  I  ablet  to  radium  of  7000  activity  t  h  rough  a  thin 
iroduced  by  twelve  hours,  and  10  II.  by  twenty- 

100  produces  ."   II.  in  fifteen  minutes  and   10  If. 
lire    radium   bromid.     radio-activity     1>00. ()()(). 
MI'  es  and    10  II.  m  1  en  m unit es. 

ilxknecht   units  from  radium  treatments  over 

II. 


RADIUM  1207 

Oudin  has  in  his  possession  a  specimen  of  radium  of  1,. 500,000  activ- 
ity, which  takes  an  hour  to  produce  3  II.,  but  which  will  produce  an 
erythema  lasting  a  month  from  a  fifteen-minute  application. 

1).  1).  (Danlos  ?)  in  Le  Kadium,  Sept.  lo,  1900,  reports  the  use  of  a 
1  eg.  square  of  copper  with  1  eg.  of  pure  radium  sulphate  incorporated 
in  a  varnish.  To  test  the  dosage  he  applied  this  to  different  places  on 
his  forearm  for  from  five  seconds  to  fifteen  minutes.  A  two-minute 
application  was  followed  after  a  very  variable  period  by  a  slight  red- 
dening of  the  skin.  A  ten-minute  application  led  to  an  actual  ulcer, 
requiring  two  or  three  months  to  disappear. 

Dosage  of  the  Emanation. —  Inhalations  of  air  laden  with  the 
emanation  from  radium  should  be  prescribed  with  caution.  Small 
animals  which  are  allowed  to  breathe  only  air  pretty  well  saturated  with 
it  die  very  quickly  from  its  effects. 

It  seems  to  the  author  that  the  best  method  is  that  by  which  the 
emanation-laden  air  is  very  largely  diluted  with  ordinary  air.  The 
ordinary  screen  radium-applicator  may  be  used  for  this  purpose,  remov- 
ing the  protective  sheet  of  metal,  celluloid,  or  rubber,  and  applying  a  few 
drops  of  water  to  the  exposed  radium  salt.  The  apparatus  may  be 
held  within  a  couple  of  inches  of  the  open  mouth  and  nostrils.  Only  the 
greatest  radio-activities  give  off  sufficient  emanation.  The  other  form 
of  apparatus  for  utilizing  all  the  emanation  (p.  12ol)  must  be  used  with 
caution.  Seventy  milligrams  of  radium  supplies  enough  emanation 
for  the  treatment  of  an  entire  roomful  of  people  in  an  emanatorium. 

Inhalations  of  the  emanation  may  also  be  made  by  inhaling  air, 
which  has  to  bubble  through  a  solution  of  thorium  nitrate,  but  these 
are  very  weak.  1  ing.  of  radium  giving  out  as  much  emanation  as  20 
pounds  of  thorium. 

The  curie  is  a  quantity  of  emanation  which  is  in  electric  equilibrium 
with  1  gram  of  radium.  The  practical  unit  of  emanation  either  for 
inhalation  or  in  solution  is  the  microcurie  or  one-millionth  of  a  curie. 

The  wachc  unit,  formerly  used,  represents  the  electric  energy  in 
volt  hours  multiplied  by  1000.  A  common  dose  of  emanation  is  a  liter 
of  water  containing  000  mache  units,  and  this  may  be  given  several  times 
a  day.  About  2.~>00  mache  units  equal  1  microcurie.  The  number  of 
mache  units  in  a  glass  of  water  may  be  directly  measured  by  a  special 
electroscope  called  the  fontactoscope. 

Tubes  of  emanation  (dosimetric)  are  sold.  They  are  full  of  air  as 
"oniplt'trly  saturated  as  possible  with  the  emanation  from  pure  radium 
bromid.  They  are  either  capillary  glass  tubes  or  hollow  needles. 
They  are  specified  1o  contain  a  certain  number  of  millicuries  and  are 
equal  in  effect  to  thai  number  of  milligrams  of  the  purest  radium. 
Hut  their  radio-activity  is  very  quickly  lost  and  is  reduced  one-half  in 
three  <  >r  \<  >ur  days. 

ler  subcutaneous  injection  ot  .">  or  10  c.c.  of  water 
emanation  t  he  t  issues  of  t  he  (Mil  ire  body  and  even 
to  be  radio-active.     This  extremely  rapid  diffusion 
n  l  he  case  of  oil  sat  u  rated  wit  h  the  enianat  ion,  which, 
a  si  ronger  local  effect . 

Experiments  by  the  Author  Februray  24,  et  seq.,  1904  >  with  a 
Solution  Exposed  to  the  Radiation  from  Radium.-  The  solution  was 
made  by  immer-um'  a  sealed  lilass  tube  conta 

0  (i 


ll2t')S  Mi:i)I(  Al.    KLKeTKHTrV    AND    H<">XT<  I KX    RAYS 

i(i. (I  pel1  cent.  XaCl)  for  fourteen  davs.  The  \vhole  was  kept  in  a  small 
iron  safe  \vei«;hin»;  7~i  pounds.  Tested  in  a  variety  of  ways  this  solution 
seemei  1  not  to  be  radii i-act  i\'e. 

The  solution  was  not  luminous  in  the  dark. 

It  was  not  fluorescent  when  exposed  to  f;asli<j:ht  or  the  Cooper- 
Hewitt  mercury  vapor  li^ht,  or  the  .r-ray  direct  or  shaded,  or  the  ultra- 
violet ray. 

It  did  not   cause  fluorescence  in  Willemite. 

A  piece  of  \\illemite  immersed  in  this  solution  ulows  as  well  as  if  in 
•water,  and  almost  as  well  as  if  not  in  a  liquid,  when  exposed  to  the 
Cooper-Hewitt  li^ht  (faint  irreen  crystalline  u'lou )  or  to  the  .r-ray, 
either  direct  or  through  a  hand  or  a  book  (\\hite  uluw),  or  to  ultra- 
violet ray  vacuum  electrodes  (brilliant  iireen  Li'lowi .  or  to  the  ( iorl  till  ra- 
violet  ray  lamp  (very  brilliant  <iTeen  trlow,  continuing  as  a  white  idow 
for  five  minutes  after  the  liirht  is  turneil  off).  .In  the  last  experinienl  the 
piece  of  \Yillemite  held  close  to  the  eyes  in  the  dark  after  1  he  ult  ra violet 
ray  is  turned  off  produces  the  sensation  of  a  brilliant  larire  white  liuht. 
The  difference  is  that  t  he  ido\v  is  whiter  when  t  he  solut  ion  is  used  than 
•without  it . 

The  same  solution,  normal  saline,  exposed  to  the  radiation  from 
radium  in  another  experiment  by  t  he  aut  hor  i  Feb.  '2  I.  1  !H)  1 1  was  mixed 
with  an  equal  quantity  of  a  solution  of  fluoreseene.  CUT.  i  to  1  pint. 
A  thin  transparent  rubber  ba.ir  filled  with  this  solution  was  laid  on  top 
of  two  silver  coins,  under  which  was  a  kodak  photographic  film  in  black 
and  oranji'e  envelopes.  The  whole  arrangement  was  in  a  photographic 
dark  room.  Xo  photographic  impression  was  made  upon  the  sensitized 
plate,  thou.ii'h  the  experiment  lasted  eighteen  hours.  The  same  hijiiid 
could  be  seen  to  fluoresce  brightly  when  exposed  to  daylight. 

Experiments  on  the  Physiologic  Effect  of  Normal  Saline  Solu- 
tion Exposed  for  Two  Weeks  to  the  Radiation  from  Radium  (by 
Ur.  I*.  C.  Kemp  at  the  Physiologic  Laboratory  of  the  College  of 
Physician-  and  Surgeons  with  solutions  prepared  by  1  he  author). — 
Ej'jH-rinicnt  \<>.  /.  -March  5.  I'.iOl: 

A  cat  \veiji'hinji  '_'  I  1  .">  Lnn.  received  in  the  back  a  hypodermic  injection 
of  \  ouii''e  of  t  he  above  solut  ion. 

A  ral>bit  \\cmlnnL!.  !*!)()  ;j.'m.  recei\"ed  a  similar  injection,  ',  ounce  of 
the  same  solution. 

Neither  of  these  produced  any  local  irritation,  but   there  was  slight 
temporarv  intestinal  trouble  in  the  cat. 
Ej'fit  i-imi  nl  .\u.    -'.       March    1  1.    I'.lDl: 

A  do^-  weiu'liin.u'  about    UK!!1  uni.  was  ethei-i/.ed  and  the  riirht  carotid 
arter\-  \vas  o pencil  and  connected  wii  h  a  manometer  which  registered  the 
ire.-r-ure  upon  a  chart.      '1  he  lett   femoral  vein  was  incised,  and  at 
re,   of  the  above  .-oluiioii   was   injected.      A   lew   minutes   later  a 
iiinl    of  the  solution    was   injected.       I  lie  do^  \\'as   not    incon- 
in  any  wav  at    first,  and   was  presented  at    a   meeting  oi   the 
ition   of  the   (ireatei'  ('it\'   of   \eu    \  ork   a    few   e\-eiun.L;s 
'   lime  he  trott  ed  a  round.  \\  a  ,'j '_:  m  ^  his  tail,  and  apparent  ly 
i'h.  but   he  died  a   fe\\   days  later,  evidently  in  coiisecjiienci.1 
h.  bui    '  ,   '    ,vh\    it   was  difficult   t  o  say. 

i-nts  ilescribi'd  above  the  only  symptoms  at   the 
;m    \' i  re  tliu.-e  direct  Iv  at  t  rilnit  able  to  the  saline  solu- 
•  Hi    o|   bloii(l-|!res.-iire.      There  were  none  a] >par- 


KADI  I'M  12(i(.) 

RADIUM  THERAPY 

'1  his  consists  most  commonly  in  the  application  of  a  radium  prepara- 
tion as  directly  as  possible  to  a  local  lesion  and  leaving  it  in  contact  for 
minutes,  hours,  or  days,  according  to  the  radio-activity  employed  and 
the  extent  of  the  tissue  changes  desired.  The  more  filtering  material  is 
interposed  to  arrest  the  less  penetrating  rays,  the  longer  the  application 
may  last  and  the  greater  is  the  deep  effect  secured. 

RADIUM    IN    THE    TREATMENT    OF    LUPUS 

A  radio-activity  of  20,000  is  applied  for  about  twenty-four  hours  and 
causes  ulccration,  which  heals  slowly  and  leaves  a  cicatrix  having  a 
natural  appearance  and  probably  completely  free  from  lupus.  This  is 
the  ulcerative  method  as  distinguished  from  the  dry  method. 

The  latter  method  seeks  to  modify  the  diseased  area  without  destruc- 
tion of  tissue.  Radium  of  an  activity  of  200,000,  300,000,  or  1,800,000 
(pure  radium  bromid)  may  be  used  in  applications  of  from  one  or  two 
to  five  or  six  minutes  each  day  for  several  days. 

A  irlass  tube  containing  20  mg.  of  a.  radium  salt  of  2.000.000  activity 
owned  by  the  author  can  be  applied  five  minutes  only  once  in  three  weeks 
to  any  particular  spot,  but  if  filtered  by  -j*  mm.  of  aluminum  the  applica- 
tion may  be  either  three  times  as  long  or  may  be  made  once  a  week. 

The  results  have  not  been  so  good  in  deep  ulcerations  from  lupus  or 
where  the  mucous  membrane  of  the  nose  or  mouth  are  involved. 

Radium  is  applied  especially  to  the  nodules  left  after  Rontgeno- 
therapy, Finsen  therapy,  or  other  treatment,  and  which  are  often  the 
site  of  recurrences. 

RADIUM    IN    THE    TREATMENT    OF    SKIN    DISEASES 

Verruca.-  Young  warts  yield  readily,  but  older  ones  may  be  resist- 
ant even  if  the  horny  layer  is  cut  away.  The  exposure  should  be  equal 
to  four  minutes  with  an  activity  of  1,800,000  and  a  weight  of  10  or  20 
mu\ 

Radiodermatitis. — The  author's  own  hands  and  face  and  numerous 
other  case<  which  he  lias  successfully  treated  were  cured  by  applications 
of  a  u'la—  tube  containing  20  mgm.  of  2,000,000  activity  for  thirty 
minutes  or  so. 

1  lol/knecht  has  cured  about  .">()  castes  by  a  different  method  which 
applies  only  the  iramma  rays.  A  flat  applicator  i-  coated  with  4 
mii'in.  of  radium  per  square  centimeter  of  applicator  surface.  The 
filters  used  are  0.2  mm.  silver.  1  mm.  aluminum.  1  mm.  copper,  and  a 
thin  layer  of  cotton.  The  duration  is  from  one  and  a  half  to  eiu'ht  and 
a  half  hour-. 

Eczema.  Radium  has  not  -ucceeded  as  well  as  the  r-ray  in  ec/ema 
and  prurin'o.  It  is  only  to  be  recommended  for  -mall  chronic  and  very 
circumscribed  area-,  especially  about  the  hands  and  fingers,  which  have 
per  ha  ps  failed  to  re-pond  to  the  .r-ray.  <  >n<  1m  ha-  cured  an  old  case  oi 
nniriui-  ani  by  two  ten-minute  applications  ten  days  ap^rt.  The 
radio-activity  was  1  .soii.iliiit.  wiLrhi  2-~>  mu'..  enclosed  in  glass  and  alum- 
inum, allowing  .,„',,„  <>f  the  total  radiation  to  reach  the  -kin.  This 
fraction  con-isted  practically  of  iramma  rays.  Another  method  is 

1n     Use    a     -heel     ot'    celluloid    Y;i  I'll  1-1  led    with    a    1'ei  lllcei  1   HI  (  1  io-a  ct  IV  i  t  y  a  !  1 1  ! 

separated  from  the  -kin  by  pa  ratlin  paper  and  held  in  place  for  some 
hour-,  or  until  the  appearance  oi  a  -liu.'hl  reaction,  by  strip-  ol  adhesive 
plaster:  recurrences  arc'  prevented  in  thi-  way. 


1270  MEDICAL    ELECTRICITY    AND    RONTGEX    RAYS 

Psoriasis.-  As  to  psoriasis,  radium  therapy  is  indicated  for  patches 
upon  the  face  and  about  the  nails. 

According  to  Helms,  a  two-  or  three-minute  application  of  1,SO(),000 
radio-activity  to  a  patch  of  psoriasis  causes  reddening  followed  by  dis- 
appearance of  the  spot . 

The  results  so  far  have  not  been  gratifying  in  xycoxis  (but  Blaschko 
reports  o  cures  out  of  ti  cases),  acne,  or  inipctiyo. 

Radium  Proposed  for  Hypertrichosis.-  A  plaque  1  inch  square 
coated  with  20  mg.  of  radium  element  is  used  and  recommended  by 
Dieffenbach.1  The  hair  is  first  removed  by  forceps:  for  young  persons 
the  radium  is  left  in  place  over  a  zinc  oxid  plaster,  as  a  filter,  for  one 
hour,  and  possibly  for  two  hours  in  women  over  fifty  years  old.  In- 
tense dermatitis  results,  with  a  crust  that  falls  off  in  three  or  four  weeks. 
The  margin  of  the  lip  must  be  shielded  by  thick  lead.  Telangiectases 
sometimes  result  from  the  application  and  require  catelectrolysis  for 
their  removal.  The  author's  experience  shows  that  a  glass  tube  con- 
taining 20  mg.  of  radium  element  can  be  used  in  the  same  way:  moving 
it  to  different  parts  of  a  square  inch  area  with  the  adhesive  plaster  filter; 
the  author  would  not  advise  more  than  twenty  minutes  for  the  first 
application.  The  final  effect  of  this  should  be  observed  before  treating 
other  areas. 

Radium  has  the  great  advantage  of  accuracy  of  dosage1  and  accurate 
positioning,  but.  like  the  .r-ray,  it  presents  some  uncertainty  as  to  per- 
manent destruction  of  the  hair  and  as  to  freedom  from  a  red  shiny 
after-appearance  of  the  skin.  My  judgment  would  be  that  an  operator 
should  gain  his  first  experience  ujxjn  some  hairy  part  of  the  body,  and 
not  until  he  has  obtained  results  there  which  would  be  entirely  satis- 
factory to  the  patient  should  it  be  used  upon  the  face. 

Pigmentary  nevi  require  an  ulcerative  effect,  but  raxculur  ncri  d<r 
not.  An  application  producing  a  mild  erythema  is  sufficient  to  cause 
the  obliteration  of  the  small  blood-vessels  causing  this  deformity. 

Alopecia  does  not  yield  to  radium  treatment. 

Keloid  sometimes  yields  excellent  results  and,  in  the  author's  experi- 
ence, requires  strong  applications,  say  20  mg.  of  2,000  000  activity,  filtered 


1  h rough  t  he     ,,  mm.  glass  wall  of  t  he  t  ube  i  arresting 


ie  ai 


and 


ing  the  passage 


sofie-t   beta  rays),  and  aluminum  \  nun.  thick,  pe 

of  ail  the  gamma  rays  and  the  hardest  beta  rays.     The  whole  should  be 

covered  with  rubber  to  stop  the  soft  secondary  rays.      Kach  part  of  the 

keloid  requires  an  application  of  twenty  minutes  or  somewhat    longer. 

Lichen  ruber,   rebellious  unit    roxucea,  and  lupus  erythematosus 

oiiiel  inies  vield  to  radium  t  reat  ment. 

Radium   Applications   for   Chronic   Arthritis. — Chronic   arthritis 
")c  favorably  influenced  hv  applications  of  an  activity  of  100.000 
lilYerent    parts   of   the   synovia!    membrane   of   the  joint    and    the 
is    of    the    tendons.      The    alpha    rays    and    the    more    absorbable 
l>et;i    rays  are  absorbed  bv  a  sheet   of  rubber  i  mm.  thick.       I  he 
i  arise  from  this  are  diffuse  rays  of  slight    penetra- 
•nt    their  reaching  the  skin  an  additional  covering  of 
A  di-k  I)  cm.  in  diameter,  coated  with  0.10  gin.  of 
activity,   is  applied  for  two  hours  over  each  ol  lour 
out    the  joints  on  the  same  day.      The  same  applica- 

\inf-i      I'     •       n|     1 1<  >IM<  -opiitliy.    al>-t.    AtinT.    .Imir.    Klrctrollirrupv    and 
,-(.!.  \\xvi.  No.    I.  p.   i:..l. 


RADIUM  1271 

tions  are  made  over  other  areas  on  the  following  day,  and  still  a  third 
series  of  four  applications  is  made  over  other  areas  on  the.jsucceeding 
day.  Two  of  these  applications  over  the  same  areas  would  cause  only 
a  slight  erythema  without  any  bad  result.  Wiekham  and  Degrais  have 
shown  the  increased  benefit  derived  from  applications  of  very  great 
strength  through  lead  \  inch  or  more  thick  and  lasting  forty-eight  hours. 

MALIGNANT  DISEASE 

Robert  Abbe,  of  Xew  York,  has  published  the  case  of  a  child  with 
apparent  sarcoma  of  the  jaw  cured  by  radium.  This  is  about  the  only 
supposed  case  of  truly  malignant  disease  which  has  been  cured.  Weaker 
and  longer  applications  appear  to  be  the  best  in  cancer  cases. 

C.  Esdra1  reports  the  cure  of  an  endothelioma  of  the  face  by  appli- 
cations of  radium  bromid — :•>  nig.  were  used  thirty-five  times,  for  an 
average  duration  of  thirty  to  forty  minutes  each  time. 

Epithelioma. — All  forms  of  ''benign"  superficial  epithelioma — 
ulcerative,  papular,  or  exuberant — are  cured  by  comparatively  mild 
applications  of  radium.  Malignant  epitheliomata,  like  those  of  the  lip 
and  tongue,  are  benefited,  but  so  far  have  not  been  cured  by  radium,  and 
the  same  is  true  of  carcinoma. 

A.  Blasehko-  finds  that  there  are  some  recurrences  after  "euro"  of 
epithelioma  by  radium  (one  personal  case).  Ulcerated  forms  are  more 
accessible  than  non-ulcerated,  but  the  latter  can  be  cured  without  de- 
stroying the  skin  (young  proliferating  cells  being  more  susceptible). 

Darier3  treated  a  case  of  recurrent  epithelioma  of  the  cheek,  the  side 
of  the  nose,  and  the  upper  eyelid  by  applications  of  radium — 5  mg. 
of  radium  sulphate  (activitv  500, 000)  varnished  on  a  copper  plate 
25  mm.  square  was  applied  for  thirty  minutes  to  each  of  the  three 
lobes  of  the  growth.  These  applications  were  repeated  three  days  later 
and  every  eight  days  thereafter.  The  subsequent  applications  were1 
over  different  scattered  nodules,  which  represented  invasion  around 
the  growth  itself.  The  tumor  fairly  melted  away  (in  ten  days),  and 
healed  without  any  scar  tissue  and  with  the  loss  of  only  a  small  portion 
of  the  tarsal  can  ilago. 

McKen/io  Davidson  reports  J4  cure.-,  of  rodent  ulcer  (epithelioma) 
by  the  application  of  the  radiation  from  radium  enclosed  in  a  glass 
tube.1 

Francis  II.  Williams  and  Samuel  W.  Fllsworth'  use  a  capsule  con- 
taining 50  mg.  pure  radium  bromid  covered  with  celluloid  for  skin 
cancer,  etc.  It  is  applied  two  to  ton  minutes  twice  a  week,  moving  it 
about  to  secure  uniform  action. 

K.  Sch iff'  reports  2  cases  of  opitholioma  of  the  face  cured  by  radium. 
Ho  believes  that  excision  should  be  resorted  to  if  prompt  improvement 
doc-  not  follow  radium  or  .r-rny  applications. 

Radium  Dosage  in  the  Treatment  of  Epithelioma. — Kpithelioma 
requires  applications  equal  to  a  -ingle  one  of  about  ten  minutes  with 
pure  radium  bromid,  activity  l.SOO.OOO,  weight  10  mg. 


1272 


MEDICAL    K1.K(  TKiriTY    AM)    HOXTC.KN    KAYS 


A  Case  of  Recurrent  Fndothelicma  of  the  Vestibule  of  the  Vagina 

(Fig.  S/V4).-  The  disease  had  recurred  very  promptly  after  operation 
and  in  three  weeks  had  regained  its  original  size,  about  1  inch  in  diame- 
ter. Secondary  infection  had  required  the  removal  of  lymphatic  glands 
in  both  groins  and  these  also  had  recurred.  The  author's  treatment 
consisted  in  the  application  of  radium-coated  celluloid  with  a  radio- 
activity of  2"), 000  for  from  ten  to  twenty  minutes,  once  in  eight  to 
fourteen  days,  to  the  vulvar  tumor,  and  applications  of  the  .r-ray  to  the 
inguinal  glands.  There  seemed  for  about  two  months  to  be  an  arrest 
of  the  progress  of  the  disease.  The  vulvar  tumor  became  flatter  with- 
out any  apparent  change  in  breadth.  Then  there  came  a  time  when 
the  tumor  gradually  increased  in  size  and  an  irritating  discharge  began 
to  flow  from  its  surface.  During  the  course  of  treatment,  which  extended 
over  a  period  of  about  four  months,  there  was  no  material  extension  of 


u'.   s-">4.  —  Kii'lnt  hrlioma  of  the  vulva.      Treatment    \>\~  radium    and    the  .r-rav  did    not 


the  inguinal  enlargement,  but  the  patient's  general  condition  gradually 
became  worse.  She  abandoned  treatment  then  for  the  purpose  of  seek- 
in  LL  the  benefit  of  count  ry  air  and  a  va  cat  ion  from  her  duties  as  a  school 
[principal  and  died  in  a  couple  of  months.  The  case  was  referred  to  the 
tthor  b>  Dr.  Hoag. 

A  Case  of  Disseminated  Carcinoma  of  the  Breasts  and  Axillae  Treated 
bv  Radium.      The  man  ~ho\vn  in  Plate  K»  \vas  referred  to  the  author  bv 
'ler.       I  he  right   mammary  gland  and  nipple  had  ulcerated  away 
and  \:i~  another    ulcer    below   that    region.      Hoth   were  adherent 

and  ci  i  id  n   red  parchment -like  epidermis,  and  were  surrounded 

IA    •!'.  '•  •' i   margin   project  um'   ',   inch  above  the  level  of  I  he  >kin. 

(ilandulai  •   larger   than   a    hickory   nut    but    -mailer  than  a    hen's 

eu.(i  \ven  Mih  axilla'  and  were  widely  >ca  I  tered  over  1  he  front 

of  the  cli  ••  riirlit  -ide  of  the  che~t  the  >kin  over  many  of  these; 

was  red.  and  ':,<       \\.rr<- evidently   i"  •''   wav  to  break  down   into  ulcers. 


P1.AIH 


RADIUM  1273 

On  the  left  side  the  nodules  were'  smaller,  white,  and  extended  from  the 
nipple  in  a  cord-like  mass  up  into  the  axilla.  The  disease  had  been  of 
several  years'  duration;  no  operation  even  for  removal  of  a  microscopic 
specimen  had  been  permitted.  There  was  no  history  of  syphilis,  and 
two  careful  \\assermann  examinations  were  negative.  The  clinical 
diagnosis  had  always  been  carcinoma,  and  if  so,  it  was  evidently  similar 
to  the  cases  of  epithelioma  cicatrizans,  which  are  sometimes  active  for  as 
long  as  eight  years  before  causing  death.  My  patient  had  lost  weight 
and  strength,  the  skin  was  adherent  to  the  chest  wall,  and  the  use  of  the 
right  arm  was  interfered  with. 

Treatment  was  by  contact  applications  of  20  mg.  of  radium  of 
2, 000, 000  activity  in  a  sealed  glass  tube  -,:in  mm.  in  thickness,  enclosed 
in  aluminum  \  mm.  thick  and  in  thin,  soft  rubber.  Treatments  were 
three  times  a  week  for  a  month  and  after  that  once  a  week.  At  each 
treatment  several  individual  nodules  or  parts  of  the  nodular  borders  of 
the  ulcers  received  an  application  equal  to  a  total  of  fifteen  minutes  in 
each  place.  During  the  first  month  every  growth  on  the  right  sick1  had 
been  treated  in  this  way,  and  also  the  floor  of  the  ulcers,  but  the  left  side 
had  not  been  treated.  At  the  end  of  this  time  all  the  nodular  masses  on 
the  right  side  were  perfectly  flat,  the  cicatrized  ulcers  were  no  longer 
adherent,  but  could  be  raised  and  bent  double.  The  arm  could  be  raised 
to  the  greatest  extent.  The  patient  felt  stronger  and  had  gained  5  pounds 
in  weight.  The  left  side,  untreated,  showed  marked  improvement, 
strengthening  the  author's  belief  that  the  application  of  the  .r-ray  and 
radium  rays  to  cancer  develops  some1  antibody,  which  is  carried  through 
the  system  and  in  proper  dosage  produces  benefit  to  cancer  foci  beyond 
the  effective  reach  of  the  direct  rays  themselves. 

Treatment  was  begun  upon  the  left  side,  and  the  subsequent  course 
of  the  case  has  been  one  of  steady  progress. 

For  a  cancer  of  the  jaw  in  a  delicate  old  gentleman  with  heart  disease, 
an  entirely  unfit  subject  for  resection  of  the  jaw,  two  applications  of  a 
tube  of  radium  placed  right  in  the  broken-down  cavity  in  the  jaw-bone 
will  effect  a  symptomatic  cure.  The  glass  tube,  containing  20  mg.  of 
2,000,000  activity,  should  be  enclosed  in  an  aluminum  treatment  tube, 
and  this  may  be  applied  for  a  total  of  from  twenty  to  forty  minutes,  de- 
pending upon  the  destruction  of  tissue  which  is  considered  desirable,  in 
addition  to  the  specific  effect  of  the  gamma  rays  upon  living  cancerous 
tissues  which  are  to  be  converted  into  living  healthy  tissues.  If  no 
destruction  of  tissue  is  desirable,  a  lead  filter  may  be  added  and  a  soft 
rubber  covering,  and  t  he  length  of  time  or  t  he  quantity  of  radium  greatly 
increased. 

Fuimatinu'  epitheliomatn  are  usually  treated  by  'U'ickham1  by  direct 
contact,  except  for  a  thin  rubber  covering,  with  a  flat  disk  varnish  ap- 
plicator, 1  inch  in  diameter,  containing  10  mg.  of  pure  radium  salt  with 
a  certain  amount  of  barium  and  other  impurities;  its  radiation  consists 
of  (.M)  per  cent,  beta  and  1(1  per  cent,  gamma  rays.  This  is  applied  for 
an  hour  at  a  time  every  third  day  until  about  thirteen  applications  have 
been  made.  Stronger  radium  m>trument>.  like  glas.-  tubes  containing 
'_'()  or  more  milligrams  of  t  he  pure  radium  salts,  are  effect  ive  with  shorter 
applications,  and.  of  course,  weaker  instruments  require  longer  applica- 
tions; but  in  any  case  the  destruction  of  fuim'ating  epithelioma  make- 

j;rais.  UadimnthtTapy.  Kndish  LMition,  published  by  Funk  A: 
HUH.  ;ni  fin  icli-niakinir  \v<>rk. 


1274  MEDICAL    ELECTRICITY    AND    RONTGEN    RAY'S 

an  unfiltered  radiation  desirable.  The  destruction  is  a  molecular  one, 
not  accompanied  by  sloughing. 

Kpitheliomatous  ulcer  of  the  side  of  the  nose  which  had  not  healed 
permanently  by  .r-ray  or  cautery  was  treated  by  Wickham  with  an 
apparatus  varnished  with  10  mg.  of  pure  radium  salt,  covered  with  T^0- 
mm.  of  aluminum  and  1  cm.  ( ,40  inch)  of  cotton-wool  as  filters.  Seven 
applications  of  one  hour  each,  spread  over  a  fortnight,  were  followed  by 
gradual  closing  up  and  healing  of  the  ulcer  without  any  inflammatory 
reaction.  The  cure  is  apparently  permanent. 

Small  idccraihnj  and  crust-forming  epithelioma  has  been  treated  by 
Wickham  with  ~\  mg.  of  pure  radium  salt  without  any  metallic  filter. 
Five  .applications  of  forty-five'  minutes  each  were  made  in  the  course  of 
seventeen  days.  Decided  reaction  followed,  with  the  development  of 
a  crust  which,  where  it  came  away,  left  a  perfectly  sound  surface  appa- 
rently permanently  cured. 

Papillomata  and  senile  warts  are  easily  cured  by  a  single  strong 
application  of  unfiltered  radium  rays. 

The  author  has  treated  many  cases  of  epithelioma  of  the  face 
by  a  single  application  of  20  millicuries  filtered  only  by  the  glass  wall 
of  the  tube  and  the  thinnest  rubber  tissue  or  paraffin  paper.  Twenty- 
five  or  thirty  minutes  ordinarily  results  in  a  permanent  cure  with- 
out any  scar.  If  there  should  be  an  incomplete  removal  or  a  slight 
recurrence,  another  radium  treatment  will  be  effective.  The  skin  around 
the  lesion  is  protected  by  lead  T!t)  inch  thick.  The  Mayos  say  that  this 
treatment  is  preferable  to  surgical  removal. 

Carcinoma  of  the  face  with  extensive  swelling  and  ulceration  was 
greatly  improved  by  Wickham  under  applications  of  GO  mg.  of  pure 
radium  salt  through  a  lead  filter  2  mm.  thick  for  seventy-two  hours 
over  the  center  of  the  mass,  and  15  mg.  through  the  same  thickness  of 
lead  over  all  other  parts  of  the  growth  for  fifty-two  hours  each. 

Epithelioma  of  the  parotid  region  was  successfully  treated  by  Wick- 
ham, using  a  cross-fire  method  by  surface  applicat  ions  of  four  inst  ruments 
containing  25,  25.  10.  and  ~\  mg.  respectively,  filtered  by  1  or  2  mm.  of 
lead,  at  different  parts  of  tin-  periphery  all  night  for  a  fortnight  and 
changing  to  other  parts  of  the  skin  each  night.  Besides  this  an  unfiltered 
application  of  50  mg.  was  made  over  the  ulcerated  center  of  the  growth 
for  three  hour-  altogether:  and.  in  addition,  a  radium  tube  of  10  or  20 
mti'.  of  1  he  pure  salt  screened  by  1  or  2  mm.  of  lead  and  giving  only  highly 
penetrating  rays,  was  inserted  into  the  substance  of  the  growth  for  four 
periods  of  twenty-four  hours  each.  The  growth  broke  down  and 
-loughed  out  through  t  he  ulcerated  place,  and  its  base  became  movable, 
whereas  it  had  formerly  been  adherent. 

Cancer  of  the  Breast.  Wickham's  experience  shows  thai  it  is  better 
not  t,,  expose  the  lung  to  too  much  radium  rays,  but  to  use  a  cross-fire 
in1  '  '  nd.  )•! ven  when  the  -kin  is  red  and  looks  like  an  abscess  1  he  e fleet 
of  radium  may  be  obtained  without  ulceration  by  a  cross-fire  method 
with  2  mm.  or  more  of  lead  and  long  application.-  of  strong  specimens. 

\\if*kham's  u.-e  of  radium  in  cancer  of  the  breast  is  confined  to  the 
following  ea-es; 

1.  "\\  hen  the  patient   firmlv  refuses  an  operation. 

2.  "\\hen  the  surgeon  founders  the  case  inoperable. 

•'>.  ". \Jfir  complete  -urirical  removal  if  there  are  enough  very  power- 
ful radium  in-t  ruments  t , ,  cover  a  la  rtre  ext  ent  of  the  surface;  ol  herwise. 


UADITM 


1273 


the  .r-ray  is  more  effective.  Sometimes  in  a  young  patient  refusing 
mutilation  by  the  loss  of  the  breast,  the  surgeon  may  remove  the  whole 
subpeetoral  and  axillary  chain  ami  the  breast  itself  be  treated  by 
radium." 


Figures  S .").">  Mil)  >how  tin1  beiirfirial  effect  in  a  case  of  tumor  of  the 
orbit  diagnosed  as  sarcoma.  The  patient  \vas  referred  to  the  author  by 
1  )r.  (  leo.  II.  \\f\\.  A  d  iff  i1  rent  pail  of  t  he  t  umor  received  an  hour'-  a]>p!i- 
cation  once  a  week  for  a  total  of  twelve  treatments.  A  20  mu'.  tube  (>t 
2,000.000  activitv  was  enclosed  in  an  aluminum  treatment  tube,  niid 


12il>  MKDICAL    KLKCTRH  ITY    AND    HOXTOKN    RAYS 

that  iii  thin  .r-ray  metal,  and  that  in  thin  rubber.  After  the  complete 
disappearance  of  the  tumor  the  eyeball,  which  was  sightless,  was  re- 
moved as  a  matter  of  precaution. 

Applications  of  very  powerful  specimens  of  radium  have  been  re- 
ported by  Cameron,  of  Pittsburgh.  lie  saw  very  great  temporary  im- 
provement in  a  case  of  cancer  of  the  rectum  from  applications  equal 
to  200  in"',  of  radium  screened  by  1  mm.  of  lead,  and  "Teat  reaction,  fol- 
lowed by  improvement  after  eight  treatments  of  an  hour  each,  in  a  case 
of  cancer  of  the  laynx. 

He  has  observed  the  same  toxic  condition  noted  from  .r-ray  applica- 
tion- upon  a  large  cancerous  mass,  and  it  is  sometimes  even  fatal.  Cau- 
tion must,  therefore,  be  used  regarding  too  long  or  too  strong  applica- 
tions. 

\  on  Franque  reports  the  effect  of  radium  upon  an  advanced  pave- 
ment epithelial  carcinoma  of  the  cervix  removed  the  day  after  the  last 
treatment.  The  epithelium  of  the  uterine  glands  in  the  immediate 
neighborhood  of  the  destroyed  malignant  focus  was  unchanged,  while  the 
connective  tissue  seemed  to  be  undergoing  active  proliferation.  In 
some  place-  the  connective  tissue  looked  like  young  granulation  tissue 
and  contained  abundant  mult inuclear  giant  cells,  probably  engaged 
in  the  work  of  disposing  of  dead  carcinoma  cells.1  This  will  be  seen  to 
be  ;>  favorable  interpretation  of  the  effect  regarded  as  unfavorable  by 
Ki-enl  >rey. 

In  a  case  of  carcinoma  of  the  cervix  previously  treated  by  radium  and 
in  which  a  hysterectomy  was  done  later  Kisenbrey'-'  considered  that 
radium  has  caused  irritation  about  the  edges  of  tumor  and  stimulated 
if-  uTowth. 

RADIUM   PUNCTURE   FOR   CARCINOMA 

Celluloid  needle-  coated  with  radium  of  various  radio-activities  may 
be  in-erted  into  the  substance  of  a  tumor,  and  will  cause  sloughing  of 
the  tissues,   -d  that   the  tumor  may  be  extruded  <  n   ///HN.-.Y .     \   radio- 
activity of  25,000  requires  to  be  left  in  place  for  two  or  four  days  and  the 
mass  -loiiu'hs  out  a  few  days  later.     Stronger  preparations  may  be  used 
with   a    correspondingly   -holler  exposure.      Cancer  cell-  are  more  sus- 
ceptible than  normal  cell-  to  the  influence  of  radium,  which,  therefore, 
mav  IK-  considered  to  exert   a  -pecific  action.      This,  however,  doe-  not 
extend   much   more   than    ',    inch   from   the  radium-coated   -urlace.   and 
il    -eems   doubtful    whether   treatment    by    radium    is   an\    le--   likely   to 
lie  ftillowed  by  recurrence  than  suruical  treatments.      A  large  tumor,  for 
ce,   of   the   breast    would    have   to   be   punctured    in    a    number   of 
|i  rent   places,  ;md  thi-  would  require  a  general  anesthetic. 
Two  !!.")  MIL:,  u'old  needles  of  radium  or  two  :'>.">  millicuries  of  emana- 
ueedles   mav   be   left    in   a    cancer   of    the   tongue    for    -ix    hour-: 
ed    two    week-    later.      lladium    is    applied    to    the    cervical 

1    an    exci-ed  later:' 

1  in-ert-  radium  needle-  into  carcinoma  of   the  pro-tale,  but 
•     left     h mi;    enoiiiih    i"    cau>e    -loiiuhini:.      ( 'arcinoinatous 
•i  i'  -mailer  or  disappeared.      It   i-  not   -uited  to  very  la  rue 
•In  \i:i        (  'a  ivim  'ina    of   the   1  ilai  1'  ler   vieli  led    ill    t  he 


RADIUM  12,7 

same  way,  and  one  had,  at  the  time  of  the  report,  remained  cured  for 
ten  months,  as  judged  by  cystoscopic  examination. 

THERAPEUTIC   USE   OF   NORMAL   SALINE  SOLUTION   EXPOSED   FOR   TWO  WEEKS  TO 
THE   RADIATION   FROM   RADIUM 

A  ease  in  which  t  he  aut  hor  employed  this  solution  was  that  of  a  young 
woman  who  was  seen  in  consultation  with  Dr.  H.  ^Y.  Hall.  She  was 
suffering  from  pyemia  resulting  from  an  abortion.  There  were  al»ce--e- 
about  the  hip  and  other  large  joints  and  a  very  high  temperature.  The 
treatment  recommended  consisted  in  cureting  the  uterus  and  admini  — 
tering  an  ounce  of  the  radiated  normal  saline  solution  by  hypodermic 
injection  in  the  back.  An  immediate  fall  of  temperature  took  place,  and 
from  that  moment  the  patient  began  to  improve,  and  though  one  or  two 
more  abscesses  developed,  there  were  not  of  a  serious  character  and  the 
patient  was  soon  entirely  well.  The  case  is  not  regarded  as  demonstrat- 
ing a  therapeutic  effect  from  the  solution,  but  it  may  have  been  of  bene- 
fit in  connection  with  the  surgical  removal  of  the  source  of  infection. 

RADIUM   IN   EYE   DISEASES 

Colin  and  others  have  found  radium  the  best  means  of  treating 
trachoma,  conjunctivitis,  and  catarrhal  folliculit  is.  A  glass  tube  con- 
taining radium,  or  a  small  metal  ball  on  the  surface  of  which  radium  is 
varnished,  may  be  rubbed  over  the  affected  mucous  membrane  for  a 
few  minute.-. 

K.  .lacoby1  has  treated  S  cases  of  trachoma  and  '.]  of  follicular  con- 
junctivitis with  radium.  Several  series  of  four  to  eight  application-  of 
fifteen  minutes  each  were  made  with  2  mg.  of  radium  in  a  glass  tube. 
lie  does  not  report  as  good  results  as  those  obtained  from  surgical 
treatment  and  ehemic  applications,  but  it  is  to  be  noted  that  his  technic 
differs  from  that  which  is  employed  by  the  numerous,  other  ophthal- 
mologists, who  report  almost  a  specific  action. 

Vernal  Catarrh  Treated  by  Radium.— Tin1  author  has  employed  two 
different  technics.  In  or.e  the  upper  eyelid  is  everted,  an  eye-shield 
i  page  1140)  protects  tiie  eyeball,  and  the  radium  tube  covered  by  thinnest 
rubber  tissue  is  applied  directly  to  the  plaques  of  granulation  tissue. 
The  glass  lube  contains  20  mg.  of  radium  salt  of  2.000.000  activity 
and  the  usual  duration  of  application  i-  thirty  or  thirty-five  minutes. 

Another  technic  dispen-e-  with  the  eyeball  shield.  The  radium 
tube  is  in  an  aluminum  treatment  tube,  and  that  ha-  a  single  wrapping 
of  thin  .r-ray  metal,  over  which  there  is  double  coaled  adhe-ive  plaster. 
The  latter  serves  partly  as  a  filter  and  partly  as  a  means  of  keeping  the 
radium  in  contact  with  the  right  part  of  the  upper  eyelid.  ]  or  3  inch 
from  the  free  border.  The  application  lasts  an  hour. 

The  oculists  who  have  sent  the-e  cases  to  the  author  report  a  cure 
following  several  treatment-  at  intervals  of  several  months. 

RADIUM    IN    UTERINE    FIBROIDS 

I  ferine  fibroids  have  been  treated  by  curetage;  removal  of  polypi; 
insertion  tor  three  hours  of  ill  Hi  to  -~>IH>  millicurie-  of  radium  emanation 
covered  with  a  rubber  col  on  the  end  of  a  sound.  Kxternal  application, 
in-lead,  may  be  one  or  more  liram-  -uitably  filtered  over  various  ab- 
dominal point-  tor  several  hours.  Immediate  re-ult-  are  nau-ea  for 
about  one  day.  abdominal  tenderness  for  -everal  day-,  occasional 
leukorrhea  f<  >r  several  weeks. - 

:    Dclll-rh.     M,.,l.    \\urh..    Jail.     1  1.     HMIti. 

2  II.  A.  Kelly,  Virdnia  Medical  Monthly.  April.  lOlv 


1278  MKD1CAL    KLKCTHICITY    AND    ROXTGEX    RAYS 

I.  ('•.  Feinbery;1  reports  a  case  of  degenerating  uterine  fibroid  that 
showed  tendency  to  malignancy:  red  cells  2, .")()(),()()(),  hemoglobin  30, 
treated  weekly  with  radium  soft  rays;  in  six  months  the  red  cells  were 
5.000, 000,  hemoglobin  SO,  and  the' weight  increased  from  102  to  140 
pounds. 

RADIUM  IN  NERVOUS  DISEASES 

Helms  shows  that  exposure  to  radium  tends  to  bring  about  a  return 
of  seii-ation  in  the  anesthetic  areas,  in  loeomotor  ataxia. 

Zimmern  and  Raymond  call  attention  to  the  relief  of  the  lightning 
pains  in  the  same  disease. 

Abbe  reports  a  case  of  exophthalmic  goiter  reduced  in  size  by 
making  a  punctured  wound  in  the  thyroid  gland  and  introducing  a  glass 
tube  containing  0.10  gm.  of  a  radio-activity  of  300.000. 

Darier  has  cured  a  case  of  supra-orbital  anesthesia  from  a  wound 
by  two  applications  of  radium.  There  is  a  beneficial  effect  upon  para- 
lytic and  painful  conditions  of  the  nerves,  and  also  upon  certain  nervous 
states  which  accompany  convulsions  or  epileptiform  attacks. 

A  case  of  tic  douloureux  which  was  treated  unsuccessfully  by 
applications  of  radium  and  of  the  .r-ray,  and  which  recurred  after  a 
resection  of  the  inferior  dental  nerve,  was  treated  by  the  author  with 
encouraging  re.-ults.  The  .r-ray  was  applied  to  prevent  the  regeneration 
01  the  excised  portion  of  nerve. 

Capriati  reports  th<j  cure  of  a  case  of  facial  neuralgia  by  applications 
of  radium. 

TONIC   EFFECT  UPON  THE   HEART 

This  has  been  observed  by  Tonta  (Congress  of  Radiology,  Milan. 
1900). 

Ionic  Radium  Treatment. — Radium  is  carried  into  the  tissues  by 
,MI  electric  current ,  regardless  of  t  he  blood-current,  quite  deeply,  and  may 
remain  fixed  in  the  muscle  or  bone  sufficiently  to  have  a  therapeutic 
effect.5 

Hadium  ion-  passed  through  the  tissues  by  electrolysis  produced  no 
effect-  appreciable  ,-ix  or  eight  weeks  after  the  last  ioni/ation." 

Radio-active  waters  are  carried  into  the  tissues  by  the  constant 
current .' 

SUBSTITUTES    FOR   RADIUM 

I  "rani un i  and  t  horium  are  not  successful  subst  ii  utes  for  radium  even 
in  larger  quantities,  to  correspond  with  their  weaker  radio-activity. 

Mesothorium   is  an   extremely    valuable  substitute   for  radium.      It 

'.'.;:-  discovered  bv  Ilahn  as  a  transformation  product  of  thorium,  and  i- 

..  :>.   I'M  I     not   at   all  in  the  state  of  purity  attained  by  radium.       The 

thorium   now  in   u-e  iherapeutically  consists  Of  ;i  large  amount   of 

iii' •:'    matter,  about    2">  per  cent,  of  radium,  and   less  than    1    per  cent. 


icerl  am.  but   it   is  calculated  t  hat 


jrv,   vnl,   \\\vi.   No.  :;,   M.Mvh.   1'Jls, 


RADIUM  1279 

is  300  times  as  active  as  pure1  radium  and  that  it  loses  ">()  per  cent,  in 
five  and  a  half  years,  while  radium  takes  1900  years  to  undergo  an  equal 

The  mesothorium  in  use  costs  about  two-thirds  as  much  as  a  pure 
radium  salt  and  requires  a  somewhat  larger  dose.  Tested  with  an 
electroscope  it  shows  an  equal  amount  of  gamma  rays  and  can  he  dis- 
tinguished from  radium  by  the  method  on  page  1245.  In  actual  treat- 
ment it  is  found  to  be  more  active  superficially  and  somewhat  less  active 
through  a  great  thickness  of  tissue. 

Kronig  and  (Jauss  have  made  extensive  use  of  it  in  the  treatment  of 
uterine  cancer  and  fibroma.  In  both  these  conditions  it  has  been  ap- 
plied inside  the  uterus  combined  with  the  re-ray  directed  through  the 
abdominal  wall,  the  perineum,  and  the  back,  to  secure  a  cross-fire. 
Their  success  has  been  almost  invariable  in  fibromyomata  and  has  been 
good  in  cancer  in  an  early  and  operable  stage.  At  this  stage  the  radia- 
tion treatment,  preceding  an  operation  to  obliterate  the  lymphatic  and 
blood-channels,  offers  the  best  chance  for  a  permanent  cure.  The  ex- 
tensively disseminated  inoperable  cases  are  materially  helped,  but  a 
permanent  cure  is  seldom  to  be  expected.  One  requires  for  this  work 
from  20  to  80  mg.  of  mesothorium  in  a  glass  tube,  with  a  filter  of  aluminum 
and  lead  or  gold  and  an  outer  covering  of  rubber  or  cotton,  to  arrest 
secondary  rays. 


NDEX 


AnnoMKx,  fluoroscopy  of,  1017 

radiography    of,    M  !.    1017 
Abdominal    neurasthenia,    elec- 
tricity for,  525 

Abnormal  electric  react  ions,  300 
Absce-s,  dental,  in  carcinoma  of 

breast,  !M2 

hepatic,  radiography  of,  1021 
high-frequency     current   .for. 

030 
of  lung.  i>lcurai  effusion  and, 

differentiation,    1010 
thickening     and,     diifer- 

entiation,  1010 
pyopneumothorax  and,  dif- 

'  fcrentiation,   lOO'.l 
radiography  of,  lOO'J 
of  tooth,  radiography  of,  942, 

!)43,  !U4 

retropharyngeal,  radiography 
of,  !>'.>:. 

Accessory     electrode     in     .r-ray 

tubes, '700 

Accidents,    death    from   electro- 
medical    apparatus,    302 
electric,  author's  experiments 

on,  303 

manner  of  occurrence,  350 
prevention,  35s 
from      electric-lighting      cur- 
rents, 377 
from  live  \\ires,  377 
from  telephones,  :JOO 
Accumulators,      '.t'.i.      See      also 

X!iirn<i<    li'tttrric*. 
Acetalnilum,  fracture  of,  radiog- 
raphy of,  l_07i)  _ 
Acid  hypo,  s74,  >>75,  N~l> 

for  plate.-,  ssH,  ss},  SSS 
for  prints,  ss:i,  S,s4 
protecting  metal  from,  213 

wood  from,  213 
radicle  of  voltaic  cell,  s;-; 
solutions    and    skin,    currents 

from,   2ii;i 
Acid-]iroof     insulating     cement, 

28'.l 
Acids,   fatty,  decomposition  by 

Acn.  .  diathermy  for,  03s1 
elect  ro!\  -i-  in,    I  Is 
high-frequency     c'urrent     for, 

(121,   1)2."),    1172 
radium  rays  in.   1  270 
ro-acea,       ca'aphoresis       with 

er<_"»  in   in,    !  is 
static  elcctri'-ity    for,    (27 
x-ray  in,  1  172 
Acromcgalv,      radiography      in, 

1  1<  n; 
Actinium,    pure,    effective   ema- 

n:it  ion  from,  12.">2 
ray-,  121  t 

Actiii 'ter,  I1,.-).". 

B_eru.  line's.  1  I."i7 
Acti'  m,  current-  iif,  27:i 
in  plant-,  2M) 
local,  2M 

piis-aue       throui;h       trans- 
Adams'  thermome_tric  measure- 
ment  of  .r-ra\  ,711 


Additiotial   outlet,   tapping  line 

lor,   2l:{ 

Adenitis,    chronic    suppurative, 
iodin    ana|>lior"sis   for,    400 

tubercular,  jr-ray  in,  1  ls<> 
Adhesion^  of  trench  foot,  static 

wave  currents  lor,  71 
Adnexa,  suppuration  of,  livdro- 

electric  -it,--baths   for,    H7 
Adrenalin  cataphoresjs,  4(r2 
Ai'-roferric  type  of  maunet,  11:1 
After-fluctuation,  positive,  2s:i 
Aire,   anatomic,   determined   by 

Air,  absorption  of  beta  ravs  bv, 

12  !2 
of  .r-rays  by,  li'.Kj 

as  conductoi  'of  electricity,  25 

as    dielectric     for    condenser, 
24") 

atmo.-iiheric      nitrates      from, 
means  of  obtainitiK,    "iS 

compressed,  for  drvins?  static 
machine,    10 

compr-es-ion      of,      analogous 
to  electricity.  52 

constant    discharge   from  stir- 
fa f  earth   to,   51 

contact     of     metals    in,    elec- 
tricity from,  !>7 

effects  of  static  discharge  on, 
57 

hot,    moisture    in    static    ma- 
chin- and.  to 

insulation.  22-'i 

ioni/.ation  of,  by  .r-ray,  ti-to 
conductivity  and.  ill  1 
therapeutic   use-,   litii 

near  earth,  radio-active  ema- 
nation  from,    1252 

normal  ionixation  over  earth, 
54 

regulator  for  r-ray  tubes,  V-;t; 
Albuminoid-    in   stomach,    radi- 
ography of,    102s 
Alcohol  injections  for  trigeminal 
neuralgia,   505 

nervous    C'onductibility    and, 

:i  12 

Alcoholic  facial  palsy,  471 
Al''oholi.-m,     epithelioma     and, 

1211) 
Alexander's  plastic  radiographs, 

SS.~) 

Alkaline     demarcation     current, 

colloids  and,  273 
Allan!    and    (  'aiiv\  '-    treatment 

of  locomotor  ataxia,  515 
Alloys,   fusing  points  of.  20'.' 
Alopecia,     taradic    current     for, 
127 

hii;h-frei|iieiic_v     current     for, 

radium   rav-  in.   1270 
static   bath-   tor,    127 

xinc   cat-iplioresis   for.    10s 
Alpha-radium   rax-.    12-12 

pr<  idui'I  ion   of  irimma   rays 

by.    1212 

-imilat   to  .-anal   rays,   1212 
Alteration     negativity,     -igniti- 


Alternating   currents,   accidents 

-.vith,  :i77 

charginu'   from,    KKi 
death  from,  :«)",  :ji72,  :i?:j 
d'vnamo,   power  of,    i:',2 
effective  value  of,    Hi2 
effects  on  heart,  :i7:-i 
electromagnetic  interrupter 

for,  s.->7 
for     high-fre<iuenc\-     work, 

5t:i 

fre.iuency  of,   102 
generator   for   r-ray    work, 
secondary    rays    from, 
740 

with  high-tension  rec- 
tifier for  r-rav  work, 
740 

interrupter        for,     electro- 
magnetic, s57 
Villard,  s.Vi 
latent  jieriod  of  mu-cle  and, 

330 

of  nerve  and,  330 
low-ten-ion,  Leduc  apj>ara- 

tus  for,    t'.U 

maximum  value  of,  102 
muscular  contraction  with, 

3  15 

100-cycle,  101 
110-volt,  213 
oscillatory  current  and, 

difference,  552 
oscilloscope  connected  with, 

70s 

path'. 'Ionic  effects.  3t')5.  372 
physioloL'ic  effects.  2',U.  2'.'5 
rate  of  flow  of.   101 
rectifier-  for,  723 
respiratorv   paralv.-is  from, 

372 
secondary,     high-frei|Ueiicy 

j--ra\-  tube  for,  734 
sell-induction  to  make  con- 

tinuous,  140 
shock  from,  3(iO,  307 
tlierai>c",:tii-  Use  of,   I''i2 
to     test      conductivity     of 

liquid-.    Is2 
transformers,  102 

for  .r-ray  work.  Ititi-lGO 
sei'oniiary  current  in.  Ill  1 
Villaril  interrupter  for.  v~>ti 
electric-light      current,     char- 
acter of,   101 
Aluminum     cassettes     :us     plate 

holders,  sltj 
cell,  mo 

eli'ctrolytic   rectifier,    723 
in  (  'alih'-ell  interrupter,  >54 
cup  of  x-ray   tubes,  ti'.l'.t 
filter    in    j-ray    treatment    of 

skin  disease.-,    1171 
in  rnnstruction  of  stati1'  ma- 
chine, 3!l 
screen,   secondary   ra\  -   from, 

nu 

to  protect  from  r-r:!\'  b';rn~. 

7'. 's 

voltage  required  for.  0'.'7 
Alveolar  absc(>s-  cause  of  tub'-r- 

culosis,  :'53 
localization  of,  !>45 

1281 


Amak'am,   !u-ib',e,   2011 

V  ik  iiiiMtiini  .'I'  /inc  fur  vol- 
taic cell,  VI 

Amaurosis,  h.\  stenc.  -is:; 

Aiiu'iu  irrin  a,  mercur\  .  vap,  >r 
li-ht  baths  tor,  lis'.l' 

Ammeters,     11>1.      See    also. 1m- 

Ammonia,    synthetic    manufac- 

turr,  of,  .")S 
Amperage,    I'.' 

different  kinds  of,  -HI 
factors  intluenrum,  ."ill,  51 
[i  >r    dire,  :    elect  rotherapeutic 

applications.  201,  205 
measurement,    !'.' 
of  bio-electric  currents,  271 
of      hinh-frequency      current, 

mcasunni:,  7.'!s 
•  if  secondary  current,  7o5 
of  voltaic  cell,  si,  v,-, 
relation  to  physiologic  effects, 

2i<5,  :;ot 
Ampere,  -in,   Kill,  172 

theory  of  mairnetisni,  11-1 
Amperemeter,  1!M 

d'  \rsonval,   110,   l'.i:{ 
foi  .r-ray  work,  s.",o 
-hunt  circuit  with,  20:1 
. \inyi     nitrite,    etTect     on     reflex 

r-ardiac  st  i:uiilation,  :•',,',•> 
Amyotrophic     lateral     sclerosis, 
bulliar      paraly.-is      in, 
47.") 

elect  ricity   for,  51  1 
. \nachlorhydria,  radiograph  v  in, 
Hi:  ;n 

-tatic  electricity   in,   7.") 
Anaphoresis,  -toil  ' 

iodin,   ton 
Anatomi'-     as_'e    determined    by 

radio],  (ry,    11211 

An:  lotm,   radiography  in,   Ill's 
Anclectrics,  HI 

Aneiectro'omis,    2S2 

excitability   and,    2S-1 
-"vtiL'th  of,  L's:', 
A:  •  inia,     faradic     current      for, 

I  1! 

in  leukemia  from  .r-ray,   ll'O.'i 
mercury     vapor     liirht     bath- 

pernieiou-.,     diphtheria     anti- 
Toxin  in,   1  lux 
./•-r:i-     in.    1  I'.is 
Ane-the-ia.   blue-lipht,  list; 

trii-,    r.L'.S      See    aKo    Rltr- 
Ir,,    .,,',,  ,,. 
faradic  current   for,    17O 

i  •  .i irreiil    for,   ,-i2!) 

local,     iron,     interrupted    ual- 

\-auic  current-,  .",:i(l 
•    •     ii  -ina  pec. or,-.  ;,:jO 
lor    bronchial  a-thnia,  :,:',0 


Anfriokeratosis,    elect rolysis    in, 

1  is 
Ant;ioina      eavernosa,      elect  rol- 

\.-i-  for,  -till 
Aiijtlf,  sine  oi,   lno,   llll 

tangent   of,    11MI 
Animals,  development  of,  I.ixluc 

current   and,    till 
r-tat  ic  elert  rieity  and,  7  1 
elTei-ts  of  hij-'h-l'recmency  cur- 
rents on,   "i7:( 
of  radium  on,  12(10 
flcetrie  currents  in,  L'(i7,  2liS 
cause,  L'Mi 
measurement,  174 
si^e  of,  death  from  condenser 

discharire  and,  o7  1 
tissues  of.  effects  of  electricity 

on,  21K) 

electrolysis     of,     21)7.      See 
also  'El,, -troli/sis   of  ani- 
ittnl  tixxurx. 
vital  processi's  of,  static  elec- 

tricit\   and,  ."i-l 
Anions,  21s,  2.":i 
discharge  of,  2r,9 
formation  of,  2">!l 
Ankle,  radiography  of,  1071) 
.-prained,  static  wave  curn>nt 

for,  7-1 
Ank\  losis,  chlorin  cataphorcsis 

'tor,  1(1.") 
of  lower  ,ia\v,  radiograpliy  of, 

1K17 

Anodal  closure  contraction,  H31 
dilTusion,  2">H,  2(»7 
ojieninn  contraction,  .'i.Sl 
Anode,  2l,s 

application  in  nerve-blocking 

for  neuralL'ia,  .'{S") 
of    electrolytic    cell,    phenom- 
ena at,  2."ill 
transmission  of  current  from, 

25!) 
x-ray   tubes  for   radiography, 

7(10 

heavy,  7(10,  7(11 

Antagonistic    muscles,    stimula- 
tion of,  :-',  IS 
reaction,  .H!)7 

Anterior  cornua  of  spinal   cord, 
(ranjrlion-cells  ot,  source  of 
elect  ricity,   21 VS 
i  rural    paralv  sis,     171 
poliomyelitis,  I'eekham's 

method  in,  obi 
superior  spine  of  ilium,   mus- 
cular   fracture    of,     radiog- 
raphy, 1071 

Anteroposterior        radiography, 
cardiovascular         topog- 
raphy in,  1002 
of  chest,    1001-  KM).'! 
of  ethmoid   cells,  H7O,   US."), 

!i  si; 

of  frontal  sinus,  '.'70 
of  maxillary  sinus,  1170 
of   neck,   HVI 
ot   -pherK.id   cells,  ;isf, 
(,!    thirh,    1072 
Anthrax,    galvanic    current    for, 

12s 
Anticathoile  for  heavy  currents, 

7iK  i 

nl    <  •.inliilni     tube,   77(1 
of  j--r:i.\    tube,  li'i'.i,  7OO,  7 ."ill 

\\  ithout,  772 

Ant  1-1  pt  ics,  elTect   ol,  2(17 
Antitoxin  of  -arc,, ma,   12:i2 
\:  •  •   .•    .    ,       nyema    of,    i:nlioir- 


Antrum,    radiography    of,   '.I'M, 

!i.">l,  !i."i2,  Utis.'liM 
for  comparison,  Hs:5 
stereoscopic,  1IS7 
Anus,  fissure  ot,  hij/h-frequency 

current   for,  (112 

Aorta,     aneuivsm     of,     radiog- 
raphy ol,'  1(H)1,   100(1 
Huoroscopy  of,   KIO.'i 
radiotrr:i])hv    of,     1001,     lOO.'i, 

100(1 
Aortic  atheroma.  triphase  baths 

in.    I  IS 

Aperiodic  interrupter,   112,  72S 
Apex    of    luiifrs,    tuberculosis   of, 

101  1 

Aphasia,  electricitx1  for,  ,"i!7 
Aphonia,  hysteric,'  17.">,  ts:{ 
Apical  forame:!,  dental  radioj;- 

raphy  to  locate,  ll-lll 
Apostoli's   bipolar   vaginal   elec- 
trode, :<s2,  ;is:< 
method      for      uterine      fibro- 

myoma,  -t^.'i 
Ai)])endi"itis,     adhesions     after, 

ra<liofrrapliy  in,  lO.'iO 
hijth-fre(iuency     current     for, 

(ill 

Appendix,  radiography  of,  1027 
Tousey's  position'  for,   10-10 
Aprons,  .r-ray  proof,  S02 
Arc      and      inc-andescent      li;zht 

bath,  (1(12,  (i()4 
lam]>s,     Tungsten     electrode, 

(1(11) 
lights,    bath,    physiologic    ef- 

tects,    (IS.") 

Ho)iue,  (iliCi,  (itiS 

Kinsen,  tit)."),  titiC) 

I-'in.-en-Heyn,  (1(1(1,  (1(17 

1'itTard,  (Kill 

rays     from,     reflection     of, 

'(iliti,  (KiS 
tests  of,  (loS 
thera]>etitic,  6(55 

uses,  liSS 

voltaic  cells  as  power,  205 
production  of,  2()(i 
rectifier,  mercury,   H):i 
Arcet's   metal,   fusing   point   of, 

2(  11 1 
Arcinn    at    swiK'h,    prevention, 

135 
in     primary     coil     for      .r-ray 

work,  7:U 
Arm,       arteries       of,       injected, 

radiograph  of,   1  121! 
Armatures,    12o 

of  electromagnets,    1  12 
Anester.  licht  ninj;,  220 

elect  rol\  tic,   227 
Arrhenius'     theory     of    electric- 
it;  ,  S2 

Ar-emate    to    seiisibili/e    tissues 

to  licht.  tis2 

Arsenic,  radium-bearing,   12(1(1 
Artefacts  ii]ion  film,  si  1 
Arterial      h.\  perteii-  ion,      diath- 

ei  m\   in,  (10(1 
electric  st  imiilat  ion  for,   liili 

lion  for,  .").",:; 
hi>.'h-tre,|uency    ciirrent    in, 

inducto-i-e-onator        etlluve 

for,  7ii 

stal  ic  electricity  in,  7  1 
ii\  pole tisii  in,      lii^li-tre(|llelicy 

current    in,  .",27 
stat  ic   elect  riritj    in,   7  1 
ten-ion,  low,  static  electricity 


I.NDKX 


Arteriosclerosis,   high-frequency 

Autopondensation,    application, 

current  fur,  575,  (.(Hi 

.").").''> 

triphase  baths  in,    t  Is 

i-oueli,  .Mr,,  .",4(1 

Arthritic  diathesis,  migraine  of, 

for  arteriosclerosis,  o'Od 

salie\  lie  cataphoresis  fur,    tll'.i 

for  calculi,  .".Mi 

Arthritis,     blcnnorrhagic,     ga!- 

for  diabetes,  ">!I7 

v:iiiic  current   tor,    I-'  t 

tor     I)npu\tren's     contrac- 

chronic,    bipolar     d'.  \rsonval 

tion,  .V.»7 

current    static    inducto-res- 

for  gout,  tiO."> 

(inator  for,  75 

for    neurasthenia    with    hy- 

detonnans, .r-ray   in,    lli'O 

pertension,  ."..sit 

sinusoidal  current^  for,    t  1  I 

for  obesity,   I.O.'i 

diathermy  for,  (i:i7 

for    pulmonary    tuberculo- 

gonorrhea!,    of     knee,     iodin 

sis,  DOS 

anaphoresis  for,    107 

for  rheumatism,  .".(I!) 

radiography    of,     Ills 

diathermal  currents  for,  (iill' 

livpert  rophic,  radiography  in. 

for  Kaynaud's  disease,  f,8:i 

'1117 

for  sciatica,   .".it.") 

radium  in,  1270 

effects  of,   ;,17 

rheumatoid,      clilorin     ionto- 

Xacelschmidt's,  f,'M 

phoresis  in,   -II  1 

l.ad,    irArsonval    current    by, 

faradic  current    for,  421. 

.".77 

radiography  in,  1  1  Iti,  1117 

for  hypertension,  577 

sacrococcvpeal,  salic\lic  cata- 

Autoconduct  ion  by  double  Guil- 

plioresis  for,  40'.l 

leminot    spirals,    .">.".:{ 

aphoresis  for,    lO'.t 

by     (iiiillemuiot  s    spirals     in 
arterial  hypertension,   ")">i 

syphilitic,      radiography      in, 

•  •age,  /H7 

111.',  111:} 

aiiplication  \iy,  'i-'t'.'i 

tabetic,    of    knee,    ioditi    ana- 

contraindications,  .">77 

phorcsis  for,  407 

Doumer's    results    with,    in 

tubercular    galvanic     current 

measured         electromag- 

for, danger  of,  4L'(i 

netic  field,  .">7S 

uriea,  sinusoidal  currents  for, 

for  arteriosclerosis,  (>().".,  tiilti 

-141 

for  calculi.  .".Mi 

.r-ray  for,  (>:H 

for  diabetes,  ,">7it,   ")!)7 

Articular  front,  radiography  in, 

for     Dupuytren's     contrac- 

1 1  Hi 

tion,  ,")!I7 

rheumatism,   radiography  in, 

for  pout,  (!()"» 

lilt) 

for  hypertension,  .">7(.,  577 

Articulations      of      lower      jaw, 

for   neurasthenia    with   h\'- 

radiography  of,  i>li.">,  'M'.ti 

pertension,  5SS 

A-cendinir   aorta,   aneurysni   of, 

for  obesity,  (>():{ 

radiography  of,   100(i 

for  paralysis,  5'JO 

Asphyxia  in  electrocution.  5.'i(> 

couch,  545 

Astatic  inairnctie  needle,  )7.'i 

effects  ,,f,  .",17 

Asthma,  electricity  for.  4M4 

from    d'  Vrsonval's    large    so- 

high-frequency    current     for, 

lenoid,  .-,.",:{ 

.")7.").  tiO7 

lighting  by,  517 

interrupted    galvanic    current 

measurement       of       high-fre- 

as local  anesthetic  in.  5:«) 

quency  current   in,  5  17 

Atheroma,        aortic,        triphase 

therapeiric  effect    of  diather- 

baths  in,   4tS 

mic  current  in,  ti.'i  t 

Atlas,     dislocation     of,     radiog- 

Auto-intoxication     in      arterio- 

raphy in,  ii'.u 

sclerosis,  tint) 

Atmospheric  air,  nitrates  from, 

static  wave  current  for.  75 

means  of  obtaining,  5S 

Automatic   rhythmic   rheotome, 

<  learing  from  static  discharge, 

4  VI 

50 

timers     for    .r-ray    exposure-. 

moisture,  difficulties  of  ,r-ra\ 

SOU 

work  in  tropics  due  to,  MM 

Avopadro's  law.  255 

Atom,  constitution  of,  till! 

Axial  current   of  rest  in  muscle, 

number  of  electrons  in,  (112 

272 

Thomson's  theory  of,  1112 

in  nerves,  272 

Atonic    constipation,    electricity 

for,  Cil 

dyspepsia,  electricity  in,   IM1 

H  \iu\sKi  ret!.  A.    177 

int  errupter,   142,  72S 

IVtch  'intl  \M(re!  Schmidt's  I'tmti 

for,   ilii'.i 

li'.MI 

static  ele  'tricit\  in,  7:> 

for  skin  diseases,  (i'.K) 

Atrophv.      chronic,      electricity 

Ma.'k-ur.   and    milliamperi's   in   a 

for,   :,1  t 

Ccicilidpe    tube    u  it 

progressive   muscular,   bul- 

changed       li'ament       in- 

bar  paralysis  in,    17."> 

i-an.li  -ci  nee,  relation  be- 

hemilinirual,  17:, 

tween,  Mil 

muscular,    four-cell    bath    for. 

in  a  gas-filled  tube  with  un- 

1  1:> 

chamred     vacuum,     rela- 

T  ion     bet  \\  I  -e!         Stil 

current    for,  til  s 

Hacteri.-i.lal      effects      of      liigh- 

of       uterus.       ,-terility       from. 

fre-iueney     sparks,     5ti!t, 

electricity  for.  !.;:•; 

571  1 

progressive      mu-eular,      elec- 

of  radium.  125^ 

trii  it\    for,  51  ! 

il  j-ra\  .   1  150 

Attractive     fnrce     of     magnets, 

Rak>  r     paper     di-k     static     ma- 

1 12 

chine.  :;7.  :is 

Audit    -;.    n    :.--  lire,    ISO 

-tat:      n         ine  for  j-ray  pn>- 

nerve,   react  i<  >n  >  M  ,    Iti'.t 

din  tii.n,  715 

I'aldness  from  r-ray,  1  1.' '..".,  1  K'.H 
1'andage      for      immobih/.at  ion, 

ID!  1 5 
Hang's     iron     electrode     lamps, 

(it'.7,  l.lj.s,  liliit 

Hario  vacuum  j-ruy  tube.  71; t 
Harium    meal    for    ga.-t  ro-intes- 

tinal   r:nliograph.\-,    KW.". 
platinocyanid,    M).l 

Sab(,uraud   and    N'oire   pas- 
•    lilies    of,     radium     meas- 
urement  by,   121s 
screen     for     measuring    j--rav 

do-age,  1155 
sulphate   and    fermillac    meal 

for  radiography     102:', 
in     stomach     radiography, 

1021 

Hath,   arc-light,   physiologic  ef- 
fects, (is:, 
blue-light,  CS7 
cabinet,  electric,  temperature 

in,  «i.s5 
elect ric-liirht,    (i.'.il,  (i(i().      See 

also  Elirtric.-liijlit  Imtli. 
l-'ranklinic,  f.O 

h\  (Iro-electric,  combined  with 
electric-light  bath  for  obes- 
ity, liss 

mercury   vapor,  (iss 
radium,   12til. 
static,  liO 

in  obesity,  7'.', 
ultraviolet     ray,     physiologic 

effects,    tisl' 

Math-tub      divided      by      dia- 
phragm, 1^7 

for  hydro-electric  bath,  -IHC, 
Hattcries,      storage-,       ill).      See 

also  Xt<ir<iin-t-ulti.riL*. 
.voltaic.      See    \'ollnic  cell. 
Heaker  interrupter,   .20,  722 
Heard,  tinea  of,  x-ray  in,  1 1S3 
Mec  Cared,  1157 
Heck's  technic   for  radiography 

of  gall-stones,   101S 
Hecquerel  rays,    IL'.'W 
Meex  ele, 'trie-light   bath,  ti(i2 
Hell's  palsy,  electn-'ity  in,  472, 

473 

Henedikt's    treatment    of    sciat- 
ica, 50! » 
Mennett's    fracture    of    thumb, 

railioLM-aphy  of,   1  101 
Henoist   electrodensiiiK'ter,  70 
railiochromomcter,   Ml),    s!2, 

S43 
for    measuring    quality    of 

x-ray,  707 

Menzol  tor  'leukemia,  1207 
Mergi.nie's  actinometer.  1157 
diaphragm,  7'.C> 
treatment    of  intercostal  neu- 
ralgia. 507 
of  obesity,  12s 
of      triu'eniinal       neuralgia, 

51 1 1 
Herleiiiout's    x-ray    tube    uith 

ai-cessory  electn.de.   7titi 
Heta-raduim  rays,  1241,  12»2 
and  gamma   rays,   compari- 
son   between    absorbabil- 
ii.,  of,  125:; 

absorption   by   air,    1242 
effect  on  plants,  12ti() 
measurement   of  velocity 

of,  1212 
oriu'in  of,  12  i:i 
production      of      secondary 
gam tua  rav-  by,   1254 

Mi-anodal  .r-ray  tubes,  75'.' 

Mi-electropraphs,  ti'.'s 

Miehromate  cells,  <io 

Micuspi.ls.     lowe.-,     radi    u 
of.  !i:i."> 

uiiper,    radiogr:inh\'   of.   '.I.-12 
unerupted,     radiograpln 


INDEX 


Hi:  ocal    tube    for    radiographs', 

Touse\  's,  770 
Bilateral  facial  pa!.-y.  -171 
Biliary  calculi,  penetrability  of, 

'   105,1 

radiography  (if,    101s,    UUO 
Be  'k's  techim,   IOHI 
cast's,   1020,    1002 
po-ition  ,  ,f  patient,   lOl'.i 
technic,   UUs 
value,  1020 
Bilinkin's  teolimc  for  cataphore- 

si-  in   t:-tula  in  ano,    IH7 
Binding-p"-ts  of  secondary  coil, 
1  17 

trie   currents,    20s 
amperage  of,  _'7  I 
nieasureineiit  of,  L'7."i 
registering,  322 
source  of.  2sn 
Tchiriev's  conclusi  ms,  2'.'0 
voltage  of,  _'7! 
Bip"'.ar  bath  1:1  s'-iatica,  5os 
i'leetri<'    stimulation,     law    of, 
32s 

I  ir   galvanopuncturc,   3s3 

...   3s2,   3  s3 

faradic  roller  electrode,  US.') 
i  in  zai  .  ni  fi  i':  incipient  cancer 

of   breast,    Kit 
n  -  mator,         (  I'Farrel         and 

Lebailly's,  551 
i  hidin,  55o,  503 
spiral,,  00.-, 

static     inducto-resonutor    et- 
•:  iv,    Mr   low  blood- 
pressure,   ,(i 
tor  paralyzed  and  atn>- 

•      phied     muscles     frolll 

war  injurie~,  70 
Birthmarks.      See  .V, 

Bi-muth  emulsion,  ;i'.i  1 

for     stomach     radiography, 
1021 
'.     1022 

Bi-.-.rie'-   electrode    for   prosta- 
uti.-.  5s7 

Bi-ulpha'e      of      i|iiinin,      x-ray 

.vitl  ,   1235 
Black   it  Hi   oxid   in   radiograjlhy 

ich,    1022 

Black,  ninir  of  .r-ras   tubf.-,  ^  in 

liladder,       foreign'    bodie-      in, 

,f,    lOot,    lii.lt 

hitrh-:  :  eiiuency      appliear  i-m- 


•  .'  •  •     ,    .-:-        of,        hitrh-fre- 
rri-nl    for,  osl 

•    •  :     ••  -       lor,    lo_' 
,r,.,lt.    Jxj 

rtlu  ti-,     B:tt- 
irr-m    :  ir,    1J1 
'         ,    'in   i-!,.,  'trod—,   (Hi 
.    IJ10 

•  .  .  •  ;  1  - 

irretit     .  in, 


Blood-cell.-,  Xenist's  method  of 

mea-unn^   electric    resistance 

of,  :«I7 

Blood-pressure    condenser,    dis- 
charges and,  :>7_' 

d'Arsonval  current   and,  57-1 

digitalis  and,  o7,") 

hinh,  electricity  for,  tiO.'i 

Jii^h-frei|iiency     ciiiTent     and, 
573,  ,">71 

in  neurasthenia,  .">!'- 

in     sinusoidal     hydro-electric 
baths,  1!.\  440 

low,  in  tropi'-s,  ti7ti 

low-tension  currents  and,  2'.»4 
Blood-vi-ssels    of   nose,    dilated, 
electrolysis  for,    11!) 

thoracic.        radionra])hy       of, 
10O3.  loo.'i 

Blotches  on  j.lates,  XII 
Blower,  l.'l 

Blue  Hcht    anesthesia,   tisti 
baths,  Ii.x7 

penetrating  power  of,  tj>_' 
treatment,   i'i^7 

Kaiser's   method,   tiv7 
with  heat,  tis7 

Blurring    from    ditTu~eil    radia- 
tion, M'3 
in    radiograph'.",    diaphr.'it'ii.- 

for,  M-'l,  M'o 

Board  compressor,  Tousey's,  in 
radiographs'  of  urinary  cal- 
culi, KM'.i 

Bobliin,    filling,    to    certain    re- 
sistance, L'L'O 
Body  as  electrolyte,  !'.> 
ilensit\-  of  part:-  of,  M7 
eleetlicity    of,    Jti.S 
insulation  of,  I'M 
resistance  of,  IMS,  :i77,  .'iMi 
ar-a  of  electrode.-  and,  :i^7 
electrolysis  and,  301 
I'.ogue's  arc  lamp,  t'liiti.  (ids 
Bones,  changes  in,  after  castra- 
tion.   1107 

diseases     of     radiographs-     in, 
1  10.1 

gumma    of,    radiography    in. 
1 1 10 

hs  pi-rtrophied,        turbinated, 

ioni/ation  for.    107 
necrosis    of,    radiography    in, 

1  HI; 
syphilis    of,     in    animals,     ra- 

diogi;iphy  in,    1111 
radiographs-    in,    1  1  10 
tuberculosis    of,    radiography 

in,   1120 
s-r:\\   in,  1  is; i 
tumors     of,     radic  igraphs'    in, 

I  1  i  ).•> 

Bo   -••  r,  loo 

B'  >r<iier's  radiometric  i  ints,  1  l.'iii 
tre.-ii  mi  nl  n!  Hi'-'  '1:1  inelice  of 


'10 


Bow-leg-,   radiography  in,   loo.',. 

Mil.  llir, 
Bos  ].  '-  law,  Jo:, 
Brachial     ni-ura!gia,     elei-tricity 

:  ".    ' 

rieiirifi-,  oOii 
I'!. MI-,   inj  irs    t« ',  static  wave 

rrelil     f.,f,     17N 

Braid,  protecting,   Jll'i 

Hi  lin,  --     !.  -  of,  radi- 

1    .    •  '  -      in,      radiograph  v      in, 
'.ml 
•  ••  \  r,f,  -timulaiioii  of,  :',."i. 


Brain,  destruction  of  motor  area 

followed   by   loss  of  faradic 

excitability,  3.') 3 

disease.-  of,  electricity  for,  olli 

effects   of   electromagnets  on, 

454 

of  x-ray  on,   1141 
olfactory       centers,       electric 

stimulation  of,   3,">3 
tumors  of,  electricity  in,  ol.S 

radiography  in,  dot 
Brass  bru.-h  electrode,  43 

point    electrode,    43 
Break    current,    production    of, 

134 

shock,   effects,   374 
.-witch  tor-direct  current,  135 
Break-finder,  211 

pole   detector   as,   211 
Breaking    of    current,    contrac- 
tions at,  331 
Breast,    cancer   of,   cataphoresis 

for,  403 

dental  abscess  in,  '.'42 
figuration  for,  5(13 
high-trec|U(  ncs    current    in, 

1 224 

inoperable,  j--ra\    in,   1223 
prognosis,  1227 
radium   in,   1272,   1274 

dosage,   12C,.i 
recurrent,  .r-ras-  in,   1222 
x-ray  in,  1  Kit),'  1222,  1221 

teclmic,    1221 

Breeze  current,  application,  GO- 
OD 

static,  direct,  (is 
indirect,  »iii,  (is 
overhead.  07.  !','! 
Bn-itunp's    telephone    for    test- 
ing  hearing,    1  si  i 
Bremer's        formulas    for    ojitic 

reaction,  4(is 

Brickner's  tube-stand,   S17 
Bromid  negative  jirints,  ss.", 
of  radium,    123'.! 
jiaper.-.  SO'l.  ssl 
jirints   directly    from   jiatient, 

ss5 

of  hand,  lO'.U 

Bronchi,       calcareous,       radiog- 
raphs of,  lOO'.t 
radiograjihy  of,  1OO2 
Bronchial  asthma,  local  electric 

t  ri  'ill  lies,  I'hvonic,  .-tat  ic  wav> 
currents     s\  ith     ozone     in- 
halation.-  for,   77 
Broiichiectasis,    radiograjihs-   in. 

I  I  I  1  .1 
Broiii'hiti.-,       galvanic      current 

lor,    131 
hig'n-.'reqiiency     current      lor. 


Bronz.ing  from  j--ray,  1  131 

•     and    >harp   s\  ire  gauges, 
.Ms 

Bn,«  i.  stains  on  j)late-,  so] 
B:  u.-h,    collect  ing,   i  it   stat  ic   ma- 
chine. 32 
disc), arge,   fox-tail,    Is 

oj    static   electricity,  57.  5S 

pencil,  tor  herpe-  zoster,  73 
electrode.-,  3S3,  :;sl 

bra--.  13 
Brushes,  121 

Bucca!    root-,    radiographs-,   (do 
Buck;.-  cellular  screen  for  arrest- 
ing -econdarv  ras's  from  ti.— 
-lie-,    S3! 
diaphragm,  s_vi 


I.XDKX 


1285 


Bullet  in  lir:iin,  ladiugraphy  in, 

'.mi 

probe,  telephonic,   17K 
Kunscri  cell,  '.'1 
Hum-     troni     conduclin^-curd, 

.1.11) 
from  electricity   -'"'>__ 

in  electrotherapy,  :;T.s 

prevent  ion,  Mss 
Kontnen-ray,  11  t.'.      See  nix. 


in  radioL'faphv  of 
stomach  and  in- 
test  ine-,  i  .">.") 

radioirraphic    expos- 
ures with,  7.1.1 
therapeutic          do>e 

from,  7.1:; 

table  of  voltajres,  710 
tran-fornier,   Salionraiid   do.-e 

with,  7"> 7 
Cadmium  standard  cell,  li:> 


in  Mat  ic  machine.  Mil 
oxalate    calculi,    penetrability 

lit',    Hi.">ii 
Calcium-tiiiiL'-tate  -creen,  s()/i 


urinarx  ,  radi>  ^rrapli >  of,  1 1 1  is. 

-. .  -ical,  radii  ijirapli;    of,   10.1(1, 

I  i  ii  ;  1  . 

:        I   •••.    7-'(l,    7^ 
with  :iluminu:n  'ci.!l,~s.-)  t 


ul     uterus,     cataphoroi.-     for, 

401 

me-otlioriiuii  for,  1^7'J 
.:'-l:r.     in,     i-'-lU 

radium  in,   1J71 

))iinctuve  for,   !_',  (i 


of,   17.' 

•      .  ::  "  :-i;niiLr,  -'•!  t 

it-,   _'  !  1 1 


raph\    of,    III)! 

•    irode,    177 

MTl'lHe'ele'ct  rode',   177,    17S 

.  17:; 
Canal  ra  v-  .-imilar  to  alpha  rays, 

1  _'  !  J 
(  '    lie,  |jo  i-       ;  :       bone, 

radioi;f:ip|,\    in,    1  I  In 
Canc.-r    cau.-rd    \>.     .,--ra\  ,    7n7. 
I  i  17 

troly-i.in.  1 1  _' 
-      trie.'./--]        iind          in,  H.TL' 

iritiary,  n  ' 

-for,         < 

; ( 

,  iii  lit,    ul     breast,    btpolai  < 


int  ract  ion,  :;iu 

•    :.   17  1 
'-.    17  1.    17.'. 

Mom'ach, 
L'l  I-' 


lirapliy    of,    lull.' 
topom'apii.\      in     anteropoMr- 

rior  railio(rrapli.\  ,  10(12 
Cane-,  fluoroM-opy  in,  '.Us 
C'arnotiti-,  production  of  ra- 


lion,   K)."i 

in  srlerodactylia,    10") 
in  sclerosis,    Uto 

cocam,  m  phaL'edenic  chancre, 

!  Ill 

cocaini/ation  by,    10."> 
copper,  for  jaw  tiMiila.-,   K)."i 

for       infected       punctun-il 
wound.-  with  fistulas,  l()t> 


electrodes     f..r.      with      lui;h- 

fre,|  leu   ;,    i-urn  ::'-.    11  1 
experiment.-  in.    Ion 
fixat  p  'ii  '  'I   ion-  after,    ion 

.    pi  cia,   ins 
for  ank\  losi>,   in:, 

liim:  I  i.-sues,   1(1.1 
lor  cunci'i-  di  brea-t,   (o:; 
nj    neck   of  Uterus,    101 

nf  ut i     i.-,    lot 
for     catarrh     of     I!i;Machian 

for    I  )upu;.  t  ren's   cont  ract  ii  in, 
!  i  i.l 

ia,   Io7 
;    •    :i-tu    ;   about   jau ,    lil.l 

.    )o7 
:  '  .  -   -.    I  Is 

wit'n  .  rt'oti:;  inacne  rosac-ea, 
1  Is 

la  •!.,  .    107 

in  1  unetri- 
ti-,    ins 

-.    : 
:  •         f  artliril 

I!       -1-,      III'.) 


12SI) 


INDEX 


•   •  :   lee,   IMS 
I'm    .-emit    ,    toil 
for  u  art-,   pit. 

.  :    •   trout,    IDs 
mai_'ne-         ,  tor  1     '  'A  arts.  Ill 

:    •    •    nc    litiu  w:irt>,    IMI; 
im-ri'uric-,  J.V.i,   !()_'• 

Ma--.  \  '-  te'-hmr,    i"-' 


li-tini-tioii,  loj 

iiiniii,        '    :'  111!    •    '       li    hen 
ruber,    11s 

h'-;.  \\'  .    fill  ..!_•"  tiip     ni     •.•- 

for   :..••  i:i.:il  >::,.    Hl-.t 


ti     rini    .    !"J 

•|'  . •.-.-    -  •    'in  i  ,  ;DJ 

:.    11  1 

v.ii  -  -    ••••  •  r,  ID) 
zin   .  i'H   :iinipi-c-ia,   His 
i  u:i,    11)7 


handle,  :!M 

in  brani-hial  neurit  i>,  .",11); 
traii.-tonniT.    |ii:{ 
voltaic  ci  II  for,  .MI,  ss 
f'anvy    aii'l    Allanl's    t  rcati 
of  loi'oniotor  ataxia,  ."'  1  ~> 


C<  11-baths,  pHJvanic,    •!:; 
:  ii   in  uriti.~,   !  \~> 
in   loroiiiotor  ataxia,    I  K5 
>inu>oi<lal,   H7 
tripha.-c, 


liatlon    o!,    '.-a.-oi'j')!"! 
effect^    "li    .-iiial!    inti-tiii'-, 

: ;  r. ' 

clc<-tncit\    ior,   .".I  1 

i-flc'-t-      o!       hiLril-t''!l-i.;Ii 


ioiii/ation  of  L'aM-  h\-,  71:! 
Oiano/V  method  to  detect  liio- 

elei-Trie    eltrrellt.-,    -'i'1 

Cliai'lioiineauV  t  rail-lot  ini-r,  7-!li 
( 'hare., t'~  joint,  railio^raph\   in, 


( 'he.-t,  area  fit,  in  di>ea.-e,   KHi") 

IIOMIinl,     KID') 

arterie.-     oi.     injeeted,      radi- 

ou'raph     of,  \\-2-l 
l,loo(!-ve~'.-  !.-  01,   ra-Hoj-'raphy 

of,  KHI:;,  HID.", 
ej  ithelioma  of,  jc-ruy  i:,.  U2.3, 

I  _'_'7 


in     pulmonary     ti.bere-iloM-, 

ID!  1 

radiosrraphy  of,  '.Hid 
anteropoVterior,   IDD1 

uith  (date  in  front,   !DO_', 

KID:', 

expo-iin   for,  slij 
for    liini.'.-,    lllll).      See    also 


not   in  -afittal  pl'u     .   KID:; 
c.l  ii.n:e,    MHKi,    ID"! 
top  '-raphir   value-,    IDiil 
witli    p'ate  1"  liind,    Kinl 

•      •  is.  1,  HUM 

in  front,   Kinl.   H)0'> 
topography      in     and  rc.posto- 
rior   r-idioi.'raph\-,    KHil 


CI       ri.l  of  i  idiiiin,    l-'.''.!l 

...       -:          1-1  I          .      !C',      ''    ' 

ol     /!'!'•     brJoT.'     r-ra\      i',     epi- 

th,  Itonia,    I.-K) 
Up,    ,,!      loi       ,-l        •    •     ,    |D| 


IN*  I)  EX 


1287 


Chloroform       .-vncope,      faradic 

Clav  electrodes,   :',Sl 

Colitis,  r-ray  lor,  C,  1  1 

current  for,    12!) 

C'leveite,  7C.."i 

Collecting    brush    ot    static    ma- 

Chlnro-i.-,   merciir--   vapor  light 

Clip,  film,  Tousey's,  !K<S 

chine,  :i2 

bath-  for.  lls'.l 

for    developing    ilental    film-, 

(  'oiler-  1  inn  of  radium  cmanat  ion, 

Choke  coil,   i:-!7 

!»:{s 

1251 

tor  r-rav  coil,   i:{7,   l:« 

Closed      magnetic      ring      trans- 

Colic-'     fracture,      radiogranhv 

separate,   Ki'J 

former,  120,  K'I.'I,  H',r, 

of,    10V.I,    1  ()!)() 

C'horea,  electricity  for,  .",l!l 

to     reduce     trolley-car 

lateral.    lO'.ll 

high-frequency      current      for, 

current,   211. 

TOU-.A  's      position      for, 

5!)  2 

Closing         shock,         pathologic 

[()!)() 

minor,  diathermv  for.  i',:is 

effect-.  :!7l 

Colloid.-,    alkaline    demarcation 

sinusoidal  currents  for,   1  11 

(  'oaL'iil.-u  ion      from      elect  re-it  \  , 

current   and,  2,:; 

Christen'.-     half-value     method. 

300 

Colon,      change.-      in      size      and 

SI  1 

necrosis  in  electrolysis,  2!I7 

moti'iitv     found     liv    j-ray, 

Chromium     aniicathode     tube-, 

Co-iklcy's  traiisilluminator,  !).sl 

I02S 

77:; 

Cocain,    nervous    conduct  ibilit  v 

obstn.ct  ion,    radiographv    of. 

Clir.tiMtiriiduiMiot.-r.              Hnlx- 

and.  :{!2 

1027 

knechfs,   1  b",:;.   Mr,  1 

Cocaintxation    l)\'    t-ataphon-i-. 

radiosniphy  of,    1027 

Cicatrices  after  burns,  galvanic 

405 

Color-blind,  etTe.-i  ,,f  .,--,-.-  -  ,,n, 

current   for,   127 

Cocevgeal     neuralgia,     electric- 

1  1  :',(  i 

indurated,          high-frequency 

it  v  for,  .".01 
t  *           r     i  ,-,.;.         i,    ,  I  <•       I../.*-  ,•!.. 

Colored        lights,        physiologic 

current    tor,   *i2i 
.r-ray  for.  (127 

(  occvgomm.a,        ti\  (It  o-elect  J 
sitx-bat'h-  for,   1  17 

effects  o|  ,  I  ,  ,  t, 

C.'icat  rici::  1       condit  ion.-,       high- 

C'occyx,    dislocation   of,    radinir- 

Comb  n!   sta!  if  machine,  charge 

frequency      current      for. 

raphy  of,  l()i',7 

in.  .'il 

5!>7 

fracture    of,    ratliography    of, 

Combined  pand%>es,    17s 

.r-ray  in,   1  17!> 

!  0117 

Comedones,  electrolysis  for,  11s 

Ciliary    ho.lv.    foreign    body    in. 

Coefficient    of  dissociation,   2.if> 

Commutator,    Ms,    121 

radiograoliy   in,   '.'Id 

of  i-\t  inet  ion.  o.s;l 

interrupter    tor    r-ray     work. 

Cine;;  atttgrapliy     of     stomach, 

Coil,  ehokf,  i:;7 

727 

author  opposed   to,    1  0:« 

for  .r-ray  coil,  i:<7,  i:!s 

Compass,  III"./.,  SIHI 

Circuit-breaker,    121,   20s,   217 

separate,   m 

Compound-wound  d.'/namo,  125 

automatic.   21li 

cutting  lines  of  force,  genera- 

Cnmiires-ed       air       for       dr\  ing 

u.-cd  in  automatic  •  ut-ofT,  217 

t  ion  of  electric  currents  in, 

static   machine,    Id 

Circuits,  capacity  of,   2  1'i 

122 

gas    in    (  iaitt'e's    trail-form--:-, 

conduct  ivitv  of,  law  of,    1  ss 

faradie.    l:;i,    1  HI.        See   also 

71  t 

derived.   1st;.    ls7 

/•'.;.'•<;./.-•   mil. 

Compression  band.   105d,  105! 

division  into  de'ived  circuits. 

galvanometer,      d'Arsonvai'.-. 

and  inflatable  bag  in  renal 

IMi 

p|.i 

radiography,    1051 

insulation,        resistance        of, 

movable,  angle  of  deflec- 

ir1     radiography      of      hip- 

n  '  e  a  -  1;  r  i  1  1  <  '  .   212 

tion  of.  in:; 

jnint  ,    1  diis 

one  -imp!'.-  and   two  derived, 

insulating      varni-'nes      for, 

in  renal   radiography,   1O5O 

Iso.    ]  ss 

212 

cylinder   and   iHaphraL'tn.   7.  -5 

principal.    1  s7 

heater,  platinum,  2iil 

in    radiogr:>piiy    ot    urina.'y 

law  of,    Iss' 

heuting  ot,  by  current,  222 
high-frequency,  5C.5 

Schf'inberg's.in  radiography 

short  ,  2dl 

fl'irtion  niii. 

diaphragm,  7  P.5 

fire  from.   20C, 

length  of  wire  for,  220 

Inofah  -;,"!:-'•  with,  7!ld 

shunt,   Is,  ,  21  1:; 

primarv.      See    I'rinuir.'/    roil. 

Sch.inl.erg-.-,       in       radi-'g- 

in   electrotherapeutics,   20:i 

resistance  of,   2.'-!2 

raphv.   S21 

starting  from  battery,   ISS 
t  ot  -d  i  mpedcnce  in     ]  }d 

determining,  221 
P.dntgen-rav.      See      /,'<',/'/<,-'  ,,- 

o;   air,   analogous  to  electric- 

undivided,    not     forming    de- 

reac'tion of,  :i:i2 

rived  circuit,   !ss 

H/,1  mkorff,   115 

(  '"!,--,  -ntra'ion    i-eil,     Horuttll  l's 

Circular  elect  n,!\  sis,  Xewman's, 

secondary,  1  15.     S<-c:iUoX.<- 

obsi  rvations,  2s,; 

for     e-oph;ige:il     stric- 

•iii'lnr'/  mil. 

example  ,  if,  2s,; 

ture,    121 

self-imluction,   l.'il 

Concentrator,    1  1 

for  urethral  strii'ture,  12d 

Tes  a,  511,  542 

Condensation      of      steam      by 

mi!-.  22-! 

t"sting  cat.acitv  of,  2:iii,  2-'), 

sta'  ic  discharge,  5'i 

Circ::lai  ion,      effects      of      stati 

total  weight   of,  221 

Condenser,   1  (s.  2M5 

i  lect  ;  icity  on,   72 

varnish  for,  212 

air  as  dielectric-  for,  215 

influence    o|,    oti    ner\-ous    ex- 
haustion,   .Sl.'i 

.r-ray,  151.     'See  al-o  1,,,','i  ;,   ,- 

paratu.-,    1H7 

in   neiir-ist  h"tiia,  ."i22 

r  •//  mil. 

capacit  \    of.   2M5 

in      neu'-omuscultir     prcpara- 

Coin  in  esophagus,  removal.  !i!>2. 

!  a  ,  215 

tioi  .   maintenance  ,  if,  :i  1  ' 

'.  i'.  i:! 

testinn  1        lirect  di 

Cir.-ula'orv       disorders,      static 

(  'oin-catcher,  '.ml 

-.;  , 

electricity  in,  7! 

C.  Id  ere;,,,,  for  r-ra\    keratos,  -. 

by     Thomsnirs     method. 

diathermy   for,  ii.15 

1144 

2:iii 

effect    of    stimulation    of    cer- 

current-     produced      i''.      ap- 

char_rim.'.  2  Id 

vical  sympathetic,  I!  IX  :U!' 

]i  icat  ion  t      a   m  rve.  :',2s 

formula'  :'  <:'.  2  !  1 

Cirrh  i.-i-  of  liver,  hyper'rophi  -. 

diagramn    iti.-  •-  piese!  1 

stal  ic  --A  avc  i  urrcnt    for     ,  .'< 

'.]  ;  

210 

Cl:ipp-I-'.:i-t!iai  i  coil,  ..--ray  from. 

la:;!0-    tni1    c\  sti  ,sci  ipje    woi  is, 

disi'luirges,  applieation,  i'1-" 

7  12 

r,.-,s 

at       hiirh      poti'inial      from 

Clark'.-     magneto-electric     gen- 

miisc'ilar      contraction      and, 

-tat  ic  machine,  :-!ii'.' 

i    Is 

:;  !  1 

.1,  a;h  -•  mi.  :iti'',  :;::;.  :;7! 

i                  -      -  .    int.  -;    ittenr.   In  - 

s  i  /<    oi    inn         a  n.i  ,  :•,  7  1 

in    of    :;.'.-     , 

drn-fara.lic  bath  for,    111', 

Cole'-     irrai       ;      nt     '    i 

t  rae-  i,  m  in.  :•'!  1 

Claii-iu.-1   theor.\    of  electroly.-is, 

;:  i  '  igraphv  .    In.;'. 

effects  of,  .Sd7 

2."io 

,  ,1,...  r.v:n  ,,  ,,,,      ,  ,,,      ..,.,-,  ,ndarv 

modification  of,  -',\  1 

Cla\ic!   ,     --  n  ture       ;.     !lu..ro.~ 

;  •  t  ~ 

on   bl  1.   :;i2 

p\    in.    HN.i 

!         •                   •    •          .    •             cur- 

on   1.1  ;-•:-,  -.--   -    .     ,-. 

radingrapln    ..!,    KI-.IN 

,r.  '.Id 

on  heart,  :;72 

radiography    of,    1002.    KM):;, 

membranous    i'!ectricit\     for, 

elecrroth,  ;  ip,  ir     , 

Id:  is 

i;-;i 

of  pa'h'  iiogic  eii'e,  ••..;.  ; 

INDEX 


!  faction,  :!!•) 

•     •    •    .c.  :«i7 

lii  ill    ir.ii:  .    M1O 

lion  b\  .    Is.', 


Hi  rvi-,   MO! I 

•  '    :'.          •  '     -•   \  -    ironi.    '  ill1. 1 

' .   mi   pnmarv   current 
•    induct  ion-coil, 'L'4:; 

i-!i     '  •  ':••   t'.ou    into  and   nut   of. 
Jlii 

Ic-.  :;s4.  ('IN 

r'k,'  :,<;:<,.  .vii,  ;,t\:,  ' 


.  :',s'.i  ' 

ork,'  '2:J,\> 
ation,    1  Is 
i  excite  .-"-ray  tube, 

[it,  r-.  s.-,7 
oil,  7M1 


•      „.    I '.I.', 
„     ,Ti,-,     tit.'. 

i  : .  l . '  - 
Is! 

r  n  lit.-, 


of  i..i,i/,.,l  air,  c,l  I 

tcasc>,  f,  t:i 
of  liquid,  cli'finitioii,   ls() 

<lc<rtVf    of    ionixation    and, 

f](^triVr  INI) 

rlfctrodcs  for  li'-tintr.   Is:-; 

iin'ilic-al  application.   1st; 

ri'i'iproc:il  of,   ls| 

ri'si>t:iHcfs  for  t.  -tin<.'.   Is  ( 

tclcphoin-  i\f  tot,  1st,  Is.-, 

t.-tiiiL'.    INJ.   l.sil 

vessels  for.    Is:-; 

\\  lieat>tone  bridjie  tor,   I.N.') 
ot  iin-tal  wires,  _'l!) 
of  solids,  _':i:i 
oj   urine,    iMi 
dt    water,   1'L's 
tlii'ory  of  elc-rtrotoiiiH,  L's.~, 
Conductors,  I'.',,  _<:;:;.   lii'.i 

c:ip;icit.\        of,        tr>iin<_'       liy 

•rin.iiisonV  metliod,  L'Hli 
copper  wire  as.    Hi! I 

•  •    !.     c-ondiu  tion     throuirli, 


Conn,.:    ' 

litrlit,  (is:; 

il    ::..     U77 

-    •     iroh  -I-  i:;.  1  l!i 

COIIIM  ction-,  I1..',,  till  ' 

.        -,     -    -    -    tor,   -MO 

'        I  live    ti.~ne,    dil/«  -tion    of, 

iL-raph;    and,    III:"' 

li  n'ial  d.\  namo,  \'2~> 
li|  at  ii  in,  atonic,  elect  ricity 
•  i,  ;.:] 

habilual.    ell  ctrieitv     fof.     I-M 

for,    i:;:; 

radio;-::,  pi.-.    ,,[,    llljs 
•        •   H,    7:; 

rreni      for, 

'-,,.     ,,      dvanieeur- 
rreni   for,  i;0.- 


from    intermittent    current 

li.\-  >elf-induction.    MO 
patliolojiic  efTeds,  :f7_',  ::7:{ 
C'ontraction.    fihrillar.v,    in   elec- 

trocut  ion.  .-).':] .  ."iUli 
from    >!  iinulal  ion,    '27 ~t,    '27 (\, 


ipncity  and,  :-!  H 
f '(intrust  in,'  IDL'l 
(  'out  n-iniiiilin  interrupter,  "L'.s 

[.(•due  modification,    14  t 
radioplioiometric    metliod    of 

1  I.-.C. 
Cnntu-ion>,      galvanic      lairrctit 

for,   lL'(i 

static  breeze  for,  7'.', 
C'onveciion,  charjre  b\',  L'l 
C'onvectiye     discliari.'('-,    L'-t.    («. 

See  also  Mfitt'r  n;,,,  ntrnnt. 
f'onverter,   rotar\',    1-'!1 
(  'onvul>ions,  epilept  ifonn,  from 

cort  ical  -timulation,  o.'i!! 
Coolidne  lube,   Ki'.l,  77t 

and  tran-tormer  for  dental 

radioirraphy,  \i:$7 
anticathode,  77ti 
div-tnirtion       of,      throuj-'h 

fihunem  current,  7so 

for  dental  radiography,  7s_> 

j/roimdin^,    7s_' 

inrandi  scenee,    77ii 

n.anipiilai  ion  of,  with  in- 
duction coil  or  Malic 
machine,  7s.~> 
with  Tousey's  yvncrator 
ol  con-tant  hi^'h-ien- 
>ion  current  or  «ith 
transformer  and  hiL'li- 
tcn-ion  rectifier,  7.sl 

motor  L'i -in  rat 01  and  ;  rans- 
fonner  for,  7,s) 

pioductioii  of  ./'-rax    in,  702 
il  ion   nt,  _7_77 

sell'-rei  '  if  \  iiiL',   77  ~> 
.-p:irL-L'a]i       ami       >pintre- 

mctcr  \\  ill,.   77'.l 
T.  iii-'\  V  -\;L"-'  >1  ion  lor',  777 
\  aeiiu'm,   77<i 

with      nnchanired     lilament 
incandc.-.  ence,     milliam- 
p,re,     and     hack   ii].     in, 
relation    between,    Mil 
r  radiation  limn.  777 
Coolinu  effect  »l  ele,  tricilv  .  IV,  1 
(  'ooper-IIewitt    lamp,  li.il'!      Si  c 
•  '         ,/-.., 

-  i-  loi   li.-t  ula>  about 

' 


11.    tor,    i::i 

-.    ,     ; 

ind  \  oltamete,-,    iM'.l 

I,    ind   re- 
-i.-tance  of,  i.'JJ 
•   nice   ol.   _']'.! 
,  '".,  f'on-d      conductor,      conduction 

L'h.   L's.-,,   L'NIi 
( 


INDEX 


1 2M) 


1001 

in  pulmonary  tuberculosis, 
101  1 

radiography  of,   1001 
Cotton  insulation  for  .r-  ray  con- 

ducting cords,  7:i7 
Couch,    aiitorondrnsation,    ."it.") 

autoconduet  ion,   5  1,", 

for  high-frequency  treatment, 

515,  .vi  t; 

indurated  fiber,  540 
Couirh,  galvanic  current  to  pro- 
voki-,  4li4 


, 

C'oxin,  S71 

Cracks    in    tilin    from    develop- 
ment     SOO 


Current  of  action,  local,  2X1 

passage       through       trans- 
former, 271! 

in     muscle    during    tonic 

contraction,  H27 
in  ureter,  H27 
of  rest,  270 
produced   by   cold   applied   to 

a   nerve,  H2S 
by    stimulation   of   nerve 
without   change  in  col- 
loid appearance,  IW  1 
strength  of,   average,   72li 
testing  for,  210 
triple  phase,   12.X 
unit   of,    171 
Cuspids,  lower,  radiography  of, 

llli") 

upper,  radiography  of,  OH2 
Cutaneous      area.-,      ^pinal-cord 
segments  and,    170 

te-ting,  L'li! I,  270 
nerves,    170 

tenderness,  areas  of,  .".01 
Cut-off,        automatic,        circuit 

breaker  used  in,  217 
Cut-outs,    L'OS. 
C.\anid      process     of     obtaining 

nitrates,   5 IS 

Cycle  of  alternating  current,  Kil 
Cyst,  hydatid.  x-ray  in.   11S."> 
in  bone,  radiography  of,  1  lOfi 
sebaceous,       electrolysis       in, 

4  1!) 
tooth,    radiography    of,    !*4~), 

Hlf, 
Cy-tin    calculi,    radiography    of, 

'1057 
Cystitis,      high-frequency     cur- 

'rent   for,  .r>Mi 
C'ystoscope,   Brown's,  ()">7 
('\-stoseop\-,     protargol    as    pro- 
ph.\lactic  alter,  lOtiO 


D\MI'I.;I>   oscillations,   .">3!) 

Daniell  cell,  !M 

DanneV     varnish      for     radium 

application.    12til> 
Dark-room,  .sJO 

liu'ht  for,  ,s70 

mercury  vapor  liirht  for,  \7() 

\\"e!sba'ch  li'irht  for,  s7O 

u  indow.-  of,   ^70 


d'Arson\-f»l      current,      indirect., 

effects,   .".71 

ozone    inhalation^    \\itli,   f>."i 
with     t-lass     vacuum     elec- 

tro. le,  effects,  o7  I  ,  .".72 
ilnpolarizablo  electrode,   271 
large  solenoid,  .",11 

autoeonduction          from, 


small  solenoid,  510 

application      of      current 

from,  55:; 

transformer  for  abscess,  oHO 
for  cellulitis,   ():',() 
for  chorea,   5112 
for  constipation,  OH) 
for  epithelioma,  021 
for  gout,  005 
for  high-frequency  current, 

544 

for  lumbago,  5(15 
for  neuralgia,  5!)I5 
for  neurasthenia  with  hy- 

pertetiMon,  500 
for  painful  flat-foot,  500 
for  periostitis,  020 
for  rectal  diseases,  014 
for  rheumatism,  000 
for  sciatic  neuritis,   505 
muscular  contractions 

with,  570 

with  .-mall   solenoid,   500 
voltmeter,   107 
Daylight  plates  for  radiography, 

M  ),s 
Dead-beat        niilliamperenieter, 

1  1  1.  'o:i 

Deafness,   electri-'ity   for,  A'.'A 
phonoirraph   for,    ]x() 
tele].  hone   in   treatment,    1x0 
voltaic  \-ert  iiro  as  test,  H05 
\"ates  method  of  t  roatinir,  4.'-i5 

Dean's  ,r-ray  tube.   702 

Death   after  .r-ray  treatment    of 

exophthalmic  iroiter,    1  l!<x 

electric,    M.'.ii,    5liO.      Se-    al-o 

Kluirm  ,it;<n,. 
from   electric  shock.   211 

tr.s     actuated     by     elect  ric- 

liu'ht  cui  rent,  :-i02 
from   .r-ra\  ,    114f, 
radi(JL"-;q.hic       determination 

of,  xf,:! 

Deciduous     teeth,     retention     of, 

Dotlei-iion   methods  of  measur- 

in-   voltage.    105 
Del-'orest        i  .....  die        or        cold 

Degenerated     ttiuscle,     contrac- 

tion in,  :;i5 
DoL'on,  ratio,,    of    motor   nerves, 

dmeno-is,  :«U.  :-;i'2 
reaction  of,  IJ01.    101.    See  also 
/,'.,/,  '  .........  .  ./.  /  .,;:/,,'„. 

|     1  )eLrree     of     vacuum     for  .r-rav 


1  )eh\  d ration  for  .r-ra\-  pur])oses. 

Mi! 
De       Kraft's      stuttf        indii'-to- 

liiL'h-froqueney  current-.  7'! 
t  ri  atnient   of  diaheto,    .  •"> 
Do  la    Hue'-  voltai.-  cell,   '<;; 
Delherm's    contraction    ;tppur:i- 

tu-.    1x7 
sialvanic    meth(.d     for    troii'.r- 

rheal   rheumatism.    125 
D.  lirium     r-ordis     in     ele   tl 
-.ion.  51-n.  :,:!(-, 


:  • ,    L'xx 

•  •  .  ,•,, n, ,1,1-  :U,,l.  .'7:-; 

I  )•:-:••     iij    rill  n  lit,    _'l'l 

•  .-     '  ..  .;i>-> 

.,l  li,    ii.1,   ixu 

1 
Dental    : '  -•',•--   in  cardni  ,ma  ' •  ' 

I'n  [-, 

method      ,,I      calculation, 

or,o.  !u;i 

w  ',,  ;•  :.ii:i;        i  if.        I),  in  I'n  ial 

:':•     •    nf,    '.'til 
,:tt;. p:..   :,  -   -.     Id.") 

.  devdnpint!  dip-  fur,  n:;x 
,;•  vcli  ipnn-nt        : .       in  ,_".:.•.. 


Dental     radioirrapln.    keratosis  j     Dpsmoid  tost,  Schwartz's,  1030 

nt    tini_',T-    frnin,   '.rj,  |     Deprez    electric    .-innal    tor    tim-     • 
mc-i-un-meni-  in,  'i.V.i  in«   m.\  otrraph,   :;  Is,  :il!t.  ol'l). 

of    antrum,    '.'.">(),    '.(.11,    '.!.">_',  :iL'l 

'.Mix  Dc.-truction     of     :-;0-milltampere 

of  ;ipic:d  foramen,  '.U'J  radiator         Conlidne         tube 

of     bicuspid-,      unerupted,  :         through  overheating,  "So 

Dr-tector.       ]inle.       extemporized, 


Develop,-!-,    X7.S 

il   canine  teeth,  unerupted,  ,          choir-t-  of,   x7s.   x.x'.l 

'•''>•'>  containing    no    hydrochinon, 

if  flariiiL'  foramina,  !'IM  XXL' 

if  toramina,  '.14 :.',  '-'i:i  eikon<i(-'en-hydroi|iiinone,   xx_> 

.f  inferior  canal,  '.nit.  'JG.">  for  forced  development,  xxx 

maxilla,   '.'O.~i  for  screen  plates,  x()x 

nerve,   '.Mi  t  Ka.-.-abian.   x'.M) 


M.  Q.,  ssl 

inetol   hydroquinonc,   ^ 

ortol,  S.S'L> 

pyro,  x7> 

pyrocatcchin,  vs-_' 

fhrolkeld-Edward.s  SOS 


It  vdopn.i  lit    It  ir,  ''.,'' 
r>',-      '.  •  .       ['ini.-i  -  '-.      '.'-'n. 
'.'.'1 

-  "i>y,  '.'^2 

in  id     .;  ,  '.'17 

."•._•:.•':•_•    flunn  i.-i't  ipf    ill, 

'.'_". 
•   '.  ::••••••:.' ' }   • 

til    :   ,    '  -:  ,.::.^-.  Hl'.i 

-.,:•'  nintr  ni  rrt  tii.  '.'17 

IC'll.   '•_'! 

iiir-ri.pl      It,  tli,  '.Us 

I-'.:.!      •      .'  -i-tci-ttjl       fill 

I,, .n  -.-.  int 


of  lower  teeth,  '<:,'! 

of  nerve,  '.I.V_' 
interior,  '.nil 

m  pulp.  <<:,_> 

ol    pulp-r-tone,   \>:>2 

n;   root-canal,  '.M'.i  Developing      clip-      lor      dental 

ol    roots  nt   crowned   tooth,  factor,    lL>.   x7x 

'.'-VJ  powder>,  Ka-tman  r-ray,  xx_> 

•    temporary   tooth.  '.)~>'.i  tank,   paragon   stone,   xx] 

n;   unerupted  teeth,  (i.Vi  tray    fol    dental   film.-,   :•:'.'.> 

lower, '.Itili, '.KIT  Deve'lopinji-out    pajn-i>.    xx  ( 

mea.-iiremr-nt   by,  H.ri."i  De\-elnpm,-nt.         blotche,        on 

of    i.pi'er  teeth,  '.<-'.-',  plat,.-,   x'.i] 

nn  horizontal  film.  '.'_'!  in  film.  x;i() 

pap, -i   fol   prim.-,  xii'.i.  '. 1 1:-;  defed.,  in.   xxi;,   x'.M) 

pcr-pectivc  in,  '.'.)•>,  '."'.:.  '.If  11  ex)  ilana  t  ion,  x(.  m 

pi  im .  examination,  !H  1  exposure  to  ruby  liL'ht.  x71 

-ter,-i-copii'.  '.Mil  fadiiiL-  ni   imaL-c,   xx7 

storage  nt   ]ilate>,  x'.i:]  film    uadied    nlT   duriiiL',    x!)0, 

.   "_•_'.   !W)  x'i] 


\enii-al     film-carrier     in,     .          in     nverexposure,     xxx 

!'L'7  in   '  rojiii-al  r-rjiintrie>,  x'Mi 

••   ei    :    diascope,  771,  772  influence  of  .r-ray  duriny,  -XM! 

ol  dental  film.,,  jii<itrin(.',  H.'jll 

i.l   film.  x77 

of  x-ra\   pictures,  x7u 


: .  „-  -  •    nd  m.'.  '•>'-' 
a.-  '  la  !./'  :    -,..-:.:• .-,  '.<'.V> 

•  I      .   '•-'_' 

• :     •   -    •    etli    d,   ''liH  1 )(  tit  i-t.    techiiic    tor,    in    dental 
brom iti    papt  r   lor.   xii'.i  --  ., ,]  •.  .   o:;x 

'         .     •  '   •       •     •    •.   7xJ  I  i    •  -:  .••  -  ,  '    ['.In,    iiirht      thcrapx- 
and     r  raii-int  mer     lor,  u  itli   h'-at   in,  'ix7 

!«:iT  D,  p    i •••  •/•  r,     olid,    double-fluid 

!,   "22.    1  !  Hi  eel!.-   uith,   ','1 

i    tor,  xjj  l)epo,it-  ii  lube.-,  MO 

•     i.c        .    x'.i:;  J),  ,,; i      irar-tnre      oi      -kull,  rc-tnrim.-.  xxx 

:        .  -     :    .•    .•      n,  nil  ratlioirraphj     in,    '.'I'-'    '.Mil  .-andy  depo,it.-  in,  ,x! 

'.•!!  I),  n-um'-      di-c;,-,.,      ./.|a\       in. 

Derived         I         t,,     |xli,     Ixx 

•  •      .   'tjl  ivn,    and    on,     -imple,    ]xii. 
.   '.'27  Ixx 

'.-;i    '.'17  !).•••       -.  7'.'1 

•  -     -      :   i      t,  !<.•,_'  Den     iiiti'-      from      fluoro,t 

-,    1J.V7 

|ii!litii,    elect 


-tain,-  on   plate.-  rlurinir,   x'.il 
tank.   x7'.i   xx] 
I'm    films,   XMI 

n  nla   lor,  xxu 
py,  tt   •    ni'-,  -7:; 

ti-mpel      •    .'.         •     I,    S'.lO 
t  line    Ic.  ,1111,  -d.    xxil.    xx] 


•     tadu  •••  iphv     ot,           I  ),   .    ation-      m  na.-al      -,-,,1.111., 

|  I  ect ,  .,1       b\  n 
m  of,                  teeth,  '.)(;_' 

i., dm  ••  .;.'.'     .  -.    Mint,                              I  ),        \Vattcville  current.       Set 

.   ii  1  _'  I  )e\t  r,ir-al      i  ,  Ii\,      ]>n-il  inn      oi 

...  .     .          .       , 

i, Hi  rr.-nt   thn      :-!..    Hix 

oi      km    -I.,!  t'h-!r,    IU.TI  1  Ii  ib,  I,  -,    a  itnconrluetion 

'  <  •         •         i  at  i,    n.aehint  .  d'.V  r-onval  ctu  rent  for,  ",7'.' 

1  ),    |\ -     •  :    ent  of,  7.', 

i  i.    •        I    t,--t       • hich-frei|iienc\      current     for, 

:      il  currents  for,    I  !_' 


INDEX 


1201 


Diahcte~,    static    electricity    in, 
71,  7.') 

.r-ra\    for,  ,"i7'.t,  o!l7 
Dialietic      L'an<rrene,      resonator 

eillu\  i-  for,  7ii 
Diarno.-i.-,   :;.Mi.      See  also   Kl,r- 


Diaphragm,    HerjtonieV,  7!»5 
IJin-Uy.  M".I 

ci  llular.   Tousey's,    7lx 
compression,   7 '.Ti 

in  radiography,  .XL'.", 
loofah  sponge*  with,  7<lli 
foiit:ii-t,  Toiisey's.  Mil 

in    rnli.i'jTaphv   of  .-pine, 

Kill',,  1017 
fluoroscop\   of,  Wo 

lor  secimdan   rays,  7'.i:i 
for  -ott    ra.\  .-,  7'.ix 
Friedlamler  shield.  7!H 

iri.-,   7'>! 
lead.   7«! 

niovi'iiii-nti  ot,  10(11 
of  .r-ra\    metal,  7'U 


<.I,...tro<l,.,-    for,    i;:« 
:  ii    i  'in  .  liMs 

•  ilii  i>,  'i:-;7 

for  arterial    hype:  tension.  »i()i; 
for  ai  thi'i'i.-,  ii:;7 
tor  i-h  iiv:i   niim  n  ,  i;:;> 
for  rlir.iiiii-  pro-ia!  i(i>,  [i:{7 
fi  ir  i-irc-,ilatoi'\   di~<  inlrrs,  ii:-!."i 

tor  di>i  :i-i-  i  if  uoiiicn,  i'.'-17 
fi  ir  i-piliirinii.  '->s 

i.  it  L'onorrhi-a.  ti:;7 

fm  ir»ut\   .1.  p..r-it>,  ill).", 

•    ....        .  ,;.;s 

r]       d-.  li  i-i 
n  ,  hnir   of.    IM'.I 

for  impot.Ti.',  .  '.':, 


100 

Diflcctrir,  .",'.! 
air  a-,  L'l.'i 

li.|iiid.-      ionixcd       hy       ultra- 
violet   ray.-,   t')7C, 
hy  .r-niy.-s  V,ns 
riL'idit\  .   _'l:; 
' 


rapliy,  ^2L' 
DifTusion,  anodal,  LN7 

cxtr;t])olar   'i;r:cnl~   of,   dire 

tion,  _'^_' 
Dijre-tive   disorders,   diathcni 

for,  <;:-;r, 


rurrent.  hreak  -wit.-h 
chariiiiiK  from,   lo_',   !0:i 
"i(H)-vo!t,  L'l  I 

for       electrol  herapeut  ie,-. 

L'  1  ", 
hiirh     ])otentia!     for     j-ra\  , 

7">0 

motor   generator   for  x-ray 
work,   7r.o 

|()()-Volt,    L'O.'i 

disdmnre     to     tesl      capacitx 
of  condi'ii-ers,  -Mil 

Statie   lllee/e.    Ii7,    IIS 

Disehartre,  .    Huh  n>i  r.     See  '  '•,    - 


l)i '  in,  n.    .liatl 

1  )      in  iitinti      nt      atlas,      radiot:- 

.       .          ,.,.- 


11.  Y.I 
ai-t  inometer  to  measure 

11.-)- 
liariuin  plat  inoe\-anid 

sereen      for      ini-asurina, 

1  loo 

Hi  r<ronie'~    a.-t  inometri    t 

measure,  1  !.",7 
Hordi.-r's         metho.U         o! 

mea-urinir,    1  l",i> 
Castex's    method    of    m.  ;i>- 

uriiii.'.  1  1  ->7 

lire,     1  I."  t 

C'ontremoiilin'-    rnetJuxl   o; 

measuring,  1  l.'r, 
furehod's  methorl  of  niens- 

urinu.   1  l.',7 
electroseope      to      mi 

ni:;,  ii.is 

erytheniti,  at  various  radio- 
irra]>hi'-  strengths.  1  li'i'J 
in    onlinary    therap     .' 

strensrth]    lHi_' 
l-'rank!iu'>    elect  roscoj>e    to 

measure,    11.  '>s 
(iaifTe's    method    of     n  .  :is- 


interruptions      in      primary 
current   and.    1  I  HI 

.1    •.  ....  •.  .,.,... 

nririL',    1  I.V) 

Kii-nlmek'-     i|uatititoineter 

to  mea.-ure.    !  i:,s 
I.iira,  hi',  mi  tliod  , 
111.', 

•••-.••:.•:.!.    1  lot 

qiiantitomcti  r   to    tii'  ilsli!    . 

!  l.ri> 

ra.l    ipl     loini'tric      11     tl 
»1    ineasiirinn.    1  lot; 

Sa!.  onrau.  1       and        No  i 

method       ol       :   , 

1  l.-,x.   MM 
Sehuart/'-         n.,-t! 


INDEX 


phy    of, 
I  >:   IL'S,     ::    •-   ular     ci  i!:traet ions 

Dry",', 

:      tes  tor  radii  ,irr:iph\  .  MIX 

•  iond  unpolarizable 
.  !,-  trod.-,  1274 
-    i]  -tiinuiation,  31l2,  334. 


EAR  diseases,  electricity  for,  43  1 
elect  roiliat'iio-is    in,    3'.!.") 
h'.L'li-lreijUeticy  current   for. 

lilil 

impeding  circulation  of,  cf-re- 

bral   rataphoresis  and,    101 

middle,  diseases  of,  combined 

d'Arsonval        and        (Midin 

methods  for,  43."i 

l-!arth,   constant   di-char<_'e  from 

surface  to  air.  .">  1 
as    storehouse    of    electricity, 

internal    structure    of,    railio- 

activity  and,    11213 
in  irn.al  ii  mizat  i'  'ii  '  •:'  air  over, 


''  /•:.•' 

rent   for,  t'.L'ii 

•    •  n  nl   ••  • .  ."17 

medical   ;  real  ment.   r,L'7 

•  i .  1 1  i  i'  1 1  - 


KHiow.  normal.   10(10 
radiography  of,   10SS 

exposure'  for,  Ml' 
tuberculosis    of,    radiojrraphy 

in.    Ill's 
Electric    accidents,    manner    of 

occurrence,    .'{."ill 
of  i)revention.  :i."s 
Tou.-cy's    experiments    on, 

olio 

anesthesia,  local.  .-,:•;() 
apparatus,     Mor-e'-    .-iirL'imr, 

-139 

arc.  production  of.   1'llii 
capacity,  inrasurinp,  I'.'il 

unit  of.    Ill 
charge,     normal,     of     earth's 

surface.  .->4_ 
carried  hy   rain.    ~>\ 
conductivity    of    cows'    milk, 

397 

of  human  saliva,  397 
of  liquid.-,  1^1) 
of  solids,  1'33 
currents,  attraction  between, 

cai-ryiiiL'  )iro!)erties  of,  l'."i7 

detection  of,   lli'.i 

di\-idin.!i  of.   IM! 

from    niajrnetir-ni.    llii 

ficncration    in    coil    ••utuim 
line.-  of   force.    !_'_' 

heat   produetii.n  b\  ,  1'iil" 

in  animal,    17 1.   i'ti7.   1'ti.S 

in  plants,  17!.  i'i!7,  I'llx 

induction  of  d\  namic  elec- 
tricitj    by,    i' :•',!' 

mea.-ureiiient   of,   Hi!) 

of  -kin.  I'li'.l 

rcL-uIation  of,   L'Ol 

^-treiiL'th   of,    139 

unit   of,    l!l 
death,     .")30.      See     also     El.r- 

triiriiti'tiH. 
dial\  sis,  frclatin  delnineralized 

douche   for   torj>or   recti,   -t3L>, 

433 
for     chronic     constipation, 


inte-tiiial  dou. -he-,  -|:;L> 
litrht,  r,;,j 

acci.lent-  from,  377 

and     telephones,     accidents 

bath,  I ','.•.9   i  '.(I! 

Hi-../,  iit-.j 

c-abinet,  r,f,n,  f,r,l 

temperaturi'   in,   lis/i 

c.nnbined      uith      hydro- 
.  I.  .  trie   bath   lor  obi  - 

it\    ,      I'lS-, 

I ol     lUL'il    :    i  ...-..:  '.-.   i,ss 
tor  arieriosdi'i-osis,   lidii 


INDEX 


ttiiecmc    iignt    natn,    ponarjie, 

tit'lL',   001 

IMeciricitv        lor       amvoiropnic 
lateral  sclerosis,  .'ill 

jLjjeeineiiy  101   pseuuoiaoes,  .11-1 

recumbent,  (Hi],  002 

for  aphasia,  .">17 

for  renal  pain,  .IK) 

bulbs,  nitrogen-filled,  0.1s 

for  atrophv,  .11  i 

for  sciatic  neuralgia.  .101 

conjunctivitis  from,  OS3 

for  Bell's  palsv,   172,  373 

for  sciatica,  .107,  .10s 

current,   alternating,    char- 

torbrachial neuralgia,  501,  500 

for     sclerosis,     amyotrophic. 

acter  of,   Itil 

neuritis,  .100 

.11  1 

POS1    III',    Mi 

for  brain  diseases,  510 

for  -pinal  diseases,  51  1 

for  radiography,  71  1 

tor  bulbar  paralysis,  475,  470, 

for  s-.  ringom\  elia,  .11  .1 

heat  production  of,  Mi,  s7 

.11  1 

lor  tabes  dor'salis,  .11  1 

induction-coil       operated 

for  cerebral  growths,  .~>1X 

for  test  icle  neuralgia.  11  1 

bv,  tor  x-rav  work,  71!) 

for  cervicobrachial  neuralgia, 

for  torticollis,  .11!) 

lamps*  210 

50(i 

for  trigeniinal  neuralgia,  .101, 

service,   207 

for  chorea,  .11'.) 

.101 

sockets,  -M<> 

for  eoccygeal  neuralgia,  501 

for  wry  neck,  .11!) 

tests  of,  fi.">7 

for  cranial  paralvsis,    170 

forms  of.   Is 

measurements,   111!) 

for  diffuse  spinal  disease,  515 

frictional.  Is,  1!).         See    also 

motor,   120 

for    diseases    of    central    ner- 

Slnhr rlrctririty. 

power  service,  207 

vous  system,   l.V>,  .11  1 

from    ganglion-cells    of    ante- 

unit of,   171,   172 

of  eve-,   '130 

rior  eornua   of   s]iinal   cord, 

reactions,  abnormal,  .'5(11 

of  motor  ganglia,  51  1,  51  1 

20  S 

normal,   3sO 

of  pyramidal  tract.  .~>1  t 

generating,   means  of.    Is 

resi-tance.   10!) 

of  sensory  patlis,  51  1 

harmful  effects,  3.11 

of       blood-cells,       Xcrnst's 

for  cnterocolitis,    131,  433 

heat    production   by,   202 

method     of     measuring, 

for  epilepsy,  51s 

history.    Is 

397 

for  exophthalmic  goiter,  520 

in  animals,   171,  207,  20s 

of  lymph,  3!)7 

for  facial  neuralgia,   "j()l 

in  eye.  20s 

response    of    nerve,    delay    to 

paral\"-is,    172 

in  nature,   .1  1 

second   stimulus,   343 

for      fourth-nerve      paralysis, 

in  plant-.   171,  207.  20s 

sleep,  4!)3,  .12s 

171 

in      radio-active      substances, 

current   for,  12S 

for  habit   spasm,   .~>l!i 

1211 

I.educ's,  4!)3,  528 

for  hemipleii-ia    .">  1  0    "i!7 

in  radium,   1211 

sparks,   nature  of,   27 

for  herpes  iTciiruliria,  "nil,  :,0l 

ionic  theory,  1!) 

stimulation  of  olfactory  cen- 

for high  blood-pressure.  00.', 

life  and,  207,  2(is 

ter:-  of  brain,  3.13 

tor  hvpoLrlossal  paralysis,   17") 

local  action  of,  303 

of  optie  nerve,  no  sensation 

for  hysteria.   ">21 

Lodge's    theory    of    transmis- 

of light  in,  3.13 

for    infantile    cerebral    paral- 

sion  through  gases.  01(1 

ten.-ion,      liydraulie     pressure 

vsis,   r>17 

magnetism  and.   relation,   107 

and,  comparison,  7S,  7!) 

sjiinal   p:iralysis,   "il  1 

manifestations  of,   Is 

tetanus,  330 

for  insanity.  .">22 

mechanical   equivalent,    123 

production,  337 

for  intercostal  neuralgia,  .107 

medical,  detinition.   17 

subniaxhnal,      of      striated 

for  intraspinal  disease.  ">l"i 

negative.   Is.    ](i.  i>.-,;i 

muscle,  337 

for  lateral  sclerosis,   .11  1 

non-conductors.   2.1 

thermostat,    Kegaud's,   203 

for  locomotor  ataxia.   .11.1 

one-fluid   theory,    1!» 

units,  4s 

for  lumbago,  .110 

passage  through   body,  300 

C.  C.  S.  system,  170 

for  mental  disorders.  .122 

through  conductor,  2.1 

variations  in  heart,  27S 

for  mult  ip'e  sclerosis,  .11  1 

through    Crooks'    tube,    040 

vibrator  for  massage,  ()02 

for      musciilocutaneous      neu- 

through  gases,   phenomena 

welding,  Mi 

ralgia.  .101 

of.  0  12 

Electricity,  air  as  conductor,  2.3 

for  myelitis,   .11.1 

through   non-conductor.   21 

animal,   cause,   2Mi 

for  nerve  injuries.    1.11 

through   solids.   201 

burns  from,   2!  Mi 

for  neuralgia,  .10  1 

through  vacuum.  04.1.  ii.11 

bv      elcetromagnetic      induc- 

for   neurasthenia.    .123.         See 

pa-Mtig  through   patient,   cal- 

tion. Kill 

also  \,'tira*th,-iiin. 

culating.    1  H 

coagulation  from,   31)0 

for  neuritis,  .10  1,  .103 

pathologic    effects    on    blood. 

compression  of  air,  analogous 

for   occupation    neuroses,    .11!  I 

3i  i 

to,  .">  2 

for  ocular  paralysis,    171 

on  power-house  workers. 

conductors  of,  I'.I,  2.1 

for  organic  diseases  of  central 

3OO 

cooling  efTects  of,  2til 

nervous  system,   .11  1 

physiologic  efforts  of.  21)2 

death    from.         See    £/.••:  '   •    (- 

for  ovarian  neuralgia,  101 

densitv    of    current    and. 

(inn. 

for  paralysis,  1.1.1 

302 

detinition.   17 

combined,   17s 

on  vertebrates,  2!'3 

discharge  of,   17 

Krb's,   177 

position      of      electrode- 

ilynamic,    78.      See    aNo    !)>/- 

hysteric,   Is3 

and.  303 

ntunii-  tlu-tririfi/. 

infant  ile,  .111.  .117 

relat  ion   of  amperage   t.  >, 

earth    as    storehouse    for,    21, 

musculospiral,   17!'.   IM) 

2!  1.1.   30  t 

221 

obstetric,   17!" 

of      voltage      to,      2!'.1. 

efTects  of,  17 

of  anterior  crural  nerve,  1M 

31  1  1 

harmful.  3.1  t 

ill   deltoid,    !7s 

positive.     I'l.    210 

on  animal  t  issues,  2!  Hi 

of  iiura~]iinatus.    !  ,  s 

quantitv  of,  unit  of,  4!' 

on  blood.  300 

ol  median  ner\  e.   IM) 

resinous,  I'.i 

on  elands,  302 

of  obturator  nerve,    1^1 

resi-tancc  to  pas-age  of,   unit 

on  heariiiL'.  302,  303 

of  plantar  nerves,    1^2 

of,   is 

on  heart,  2O3 

of  p.  ipliteal  nerves,    l^i 

static.  Is.  2.1.      See  also  Slut 

on  microorganisms,  2!)2 

i  if  scial  ic  nerve,    lv  1 

<  I.  r-tririt't. 

on  muscle,  3O2 

.  il  serratus  itiagnus,   17s 

theories  of,    I'.i 

on  nerve-fibers,  3O1 

ol  sixth  nerve.    171 

through    straight    wire,    mag- 

on  respirat  \-  >n,  _"'  1 

i>f  <pinal  accessory,    17.1 

neti.-m  induci-d  by.   K'7 

on  sight.  302 

of  sternomastoid,   177 

to    stomach,    effect    on    secre- 

on smell,  302 

•  il  ~upras])inati|s.   17s 

tion,  3.10 

i  Hi  -peciat  sen>es.  302 

of  third  nerve.    171 

transportation  of  matter  b\  . 

on  tactile  sense,  3O2,  303 

of  trape/,  iid,    177 

21)!) 

on  taste,  3O2 

of  vaiius,   171 

two-fluid  theory.   1'.' 

electron  theorv  of.  213 

peroneal,   1M 

units  of,   171  .   1  1  2 

faradic,   is.      See  also  /•'  •    •  • 

for  paraplegia.  .11.1 

:  .       (              i  .  | 

,1,,-trint;,. 

for  poliomyelitis,  .111 

voltaic,  'is.'       See  also    i 

for    abdominal    neurasthenia, 

:  u        progressive      muscular 

./.-••:•,      -, 

52o 

atrophy,  .11  i 

Electrics,    I'J 

i'J'tl 


I.NDKX 


:-         trilied    body,    attraction   of, 

Electrodes,  carbon,  43,  3x2 

Electrodes,    shovel,    for    hydro- 

for other  bodies,    2t> 

cla\  .  3s[ 

electric  bath.    -13x 

of  pi'h-bal!  by,  20 

condenser,  3x1,    ll'X 

size    for    bipolar    application, 

•  :i:L-ing  other  bodies,  with, 

for  high-frequency  current  . 

(13") 

I'l 

~>l  13    ->i  1  1     "ill  "i 

.-kin  and,  difference  'ii  poten- 

loss  .  :   .  harge  of.   23 

for      surface     applications, 

tial  between.  31HI 

I  lect  roca  rdii  'gram     '  H  '  1     3'  '  ". 

3xO     ti30 

-park    indirect     d7 

[ration       of       heart 

operation  ,,f,  .MKI 

-pong,..  43 

-'Hind-.  .;_'7 

at  distance  from  pat  lent  , 

and  in.-ulated  handle,  3X1 

in  ai  terii  isclen  i-i-.  3  I'll 

.-,1)1 

spray,  li'.l 

in  cardiac  neuroses,  3_'ll 

cords  tor,  -13 

static,  13 

in     cardiovascular    diagnosis. 

detector,    extemporized,    212 

Tousev  s.  o.VI 

_".  '1 

exploring,   Tousev's,  -I.V.I 

exploring,  4.  V.I 

•     1    •     •      :.:il   trouble  of  auri- 

external. 3s(l 

tor  fulguration,  'illl',  .">(13 

cle-.  327 

faradization  by  rolling,  3S.3 

indirect  sprav,  till 

in  hypertrophy  of  auricles,  Ml'ii 

for    cataphorcsis    with     high- 

vacuum,  ".!.-> 

<  it     let  t     Vent  ri'de.    32". 

frequencv  currents.  -11  1 

i  >:  i  itri.1   vent  nc';e.  3l'."> 

for      cutaneous      application. 

in   neurasthenia.   3_'ii 

3x0,  (130 

vaginal,  3x2,  3X3 

in  organ1.'-  arti  ria!  di-ease,  327 

Wehin-lt    interru])ter    in, 

virtual,  33X 

cardiac  disease.  32il 

3.s(l 

with  glass  sleeve,  .~>s7 

in  rapid  pulse.  327 

for  diagnosis,  3SI1,  -l.'.S 

wood  ball,  43 

in    vascular    thyroid    disease, 

for  diathermy,  Ii32 

hollow.  111) 

32ii 

for  electn.diagnosis,  Toiiscy's, 

point,  43 

of     possible     lesion     of     right 

3'.r2 

Klectrodiagnosi-.  3xil 

limb  of  Tawara,  327 

for  electrolysis  of  animal  tis- 

and    physiotherapy     in     war 

Pai  lion's   left    lateral   decubi- 

sues,  I'mi,  2(>7 

injuries,    l.'il 

tus  desirable  tor,  327 

for  faradic  bru-h,  3X3,  3S4 

condensers  for,  3(1!) 

;  ha.-es  '  if,  32."i 

currents,  3x0 

discharges  for,  3sx 

showing  irregularities  of  aor- 

for fulguration.  .".Hi',  .")(i3 

electrodes  for,  3xtl,  4.VS 

tic    insufficiency,    327 

for   galvanic   electricity,    3s(), 

Tousey's,  3H2 

of  cardiac  rhvthm,  327 

3S3 

in    alcoholic    peripheral    neu- 

Electrocardiograph/DuhamelV, 

for  galvanopuncture,  3x3 

ritis,  31i.") 

327 

for  gums,  (117 

in  ear  diseases,  311.") 

Nicolai  and  Huth's.  17.1,  32-4 

for    high-frequency    currents, 

in  eye  diseases,  3H3 

Elect  rocliemic  cauterization,  -133 

3,s(),  41  (.s 

motor  reactions  in,   1  .">."> 

equivalents,  I'.M,  l'.V2 

in  pyorrhea.  (117 

neuromuscular    reactions    in, 

Elect  ro"oagulat  ion,   (13!) 

for  hypertrichosis,  3s3 

45(3 
of  degeneration,  31'1,  3H2 

a-pl.yxia  in,  .")3li 

for  liiggs'  disea.-e,  I'd  7 

of  m\  asthenia.  3'.).") 

hy    alternating   current.    372 

for  skin,  3sli.  H30 

jirognosis  based  on.  3117 

b\    condenser  discharge,   3li'.i, 

bipolar,  3si>,  3x3 

record  of  examination,  31H1 

37n.  372.  37:-> 

\Vehnelt  interrupter  in,  3s() 

Electrodynamic     indui-tion,   di- 

b\    '•'.ntinuous    current,    372, 

for  static  electriciu  ,  43.  3X1 

rection  of  current,  122 

37:> 

for    surface   application,   3s(). 

E  lect  rod  vnamomcter,    11(3 

t,;.    crossed  wires,  I'll.", 

i  ;:in 

Siemens',  1K4 

b\    high-tension  currents.  I'll.") 

for     testing     conductivity  of 

Electrolysis,  IMS 

bv   industrial  currents,  3ii'.l 

liquids.    1x3 

bulbous-pointed    needles    for, 

b;     I  .-due  current,  .V3U.  :,:>,\ 

for  urethra,  3X3 

411) 

causes  of  death,  .'.:-;  1 

for  uterus,  3.s3 

burn-  in  37x 

changes  in,   .'.32 

glass,  filled  with  liquid,  -I'.HI 

by  voltaic  cells,  XX,  I'.Vl 

delirium  cordi.-  in,  .".31,  ."»3i> 

vacuum.  3s) 

circular.  New  man's,   120 

diagno-is,  .'.30 

handle-  for,  3xi 

conductivity  and.  31)1 

ir\    contra'  t  ion   in,    ">31, 

for  galvanopuncture,  3x3 

connterelectromot  ive         ton-e 

."i3(> 

in.-ulated.  3Sl 

during,  2">() 

hi     -  '    in,  .">3o 

interrupt  ing,  3s."> 

current   for,  strength  of,  413 

hemorrhage  in,  .">33,  r,3  1 

lion-interrupt  ing,  3s."> 

deep,  strength  of  current   for, 

.  :;::,,  :,3i  i 

Hart'.-,  for  fulguration.  .",1)2 

41  t 

-"'•"' 

hollow  wood,  use  of.  (Ill 

dest  met  ive,  377 
effect  on  body  resistance,  301 

•".--,  '."31-.-.3I 

tial      at      single      electrode, 

Faradax  's  law.-  of,  2.M 

-.  ;,:{() 

17s 
impolarizable,   27  1 

for   acne,    llx 
for  angiokerat  o-is,  -IIS 

p'h\-i                             •        .-!     death. 

d'  Vrsonval's,  271 

t'  ir  angioma  cavenn  isa,  1  I  il 

':,:>,  i 

1  )u   Hois-Heymond,  271 

for  birth-marks,   117,   117x 

•:....-.        :   .;.   ith,  -".-:( 

lie.-,  nault's,   271 

tor  cancer,    1  1  2 

[.ii    •  ••  idet.-imcter,    K.-iioist,    .  n 

in  elect  r,,!;,  t  ic  cell,  phenomena 

for  comedones,   lls 

1  ..    •  •    •  ;•  -,  .  ;-u 

at  .  2.Vi 

for  c.iniunctivitis.  vegetative. 

'  -  -   >r\  .  :n  .r-ra\    tubes,  7'iO 

mt  raga.-tric,  3x."> 

UK 

•  ..       •      • 

kaolin,   3x2,  (His 

for  cysts,  sebaceous.    1111 

-:.    -...    n  .  1's.-, 

lamp,  (Hi.     i'.  II 

tor  dermal  it  i-  papillaris  capil- 

p,  '    .:..•    '-  -  .  Ill  111 

massage  roller.    13 

litii,  4111 

.     •     -.    Iain  -      ol     b'.ih 

materials  for,  3x11 

for  e.-ophageal  stricture,    121 

mi  Millie  use.-,  3sn.  :;xl 

lor  exophthalmic  goiter,  .VJO 

:                             lie  roller,  3s."i 

ne.  die    3s:; 

for  folliculitis  vulva-,   120 

;    .-     •    .•••,   3s:; 

ot    voltaic  cell.   VI 

tor  hairs    ne\  i,    lls 

.  •  -  . 

|ilr  -ii  .:•  >gii      33s 

for    hyp'ertrichosis,   :-',oo.    3S3, 

.    ;s.j 

platinized,    1X2 

113.   311,    11.-. 

1  e.  •  v  e  , 

for  .  lei  troly.-i-,   2''7 

for    h\  pertn.  ph\    of   no-e,    llx 

for  ele.-trol.vlic  cell.  2.  V.I 

for  keloid,  4111 

- 

po-itini      :      •-.     I  on  elect  ri/a- 

•  .;   la'-rimal  -i  ricture,   121 

!    • 

ii'.  n.    303 

lor  lupus  er\  thematosiis,  -llx 

:       t  .  t  .    1  .  1 

!    -     '.    l.t'i    d       :-,      170 

for  I-,  mphaiigioma,    1  lo 

:  •       '  .      vi.  3-1 

r.  .  tal,  3xi' 

for  liiacroglossia,    121) 

: 

l)oiinn  r's,   .'.-.-, 

for  nasal  deviations,  -till 

el.  177 

vacuum,  id  1 

polypi,    1  111 

...... 

.    3x3 

-purs,    !!'< 

ingn    .••••... 

ic,  :>;, 

for  in  vi,    1  lo,    117,    1  17.x 

INDEX 


Electrolysis  for  ozena,   110 
for  pigmented  ncvi,    I  IS 
tor  p'llypi,  n:i.-;il,  410 
fur  port-wine  .-tains,  -117,   11\ 

!  17.S 

for  sebaceous  cysts,  -11!) 
for  strictures,  esophageal,   121 

o!    lacrimal  duct,    121 

of  urctlira,  420 
for  sycosis,  4  IN 
for  tattoo-marks,  418 
lor  vascular  ncvi,  -t  Hi 

tumors,  -I  Iti 
for  vegetative  conjunctivitis, 

41!) 

for  verrtiga,  41'.) 
for  vulvar  diseases,  -12(1 
for  warts,  4  111 
Fort's  linear,  420,  421 
indications  for,  410 
ionic      medication      by,      300. 

mechanism  of,  2,1(1 
medication     by,     ionic,     .'500. 

_See  also  Cataphortsi*. 
Newman's  circular,  420,  421 
ot  animal  tissues,  206 
burns  from,  208 
electrodes   for,    20S 
coagulation    necrosis    in, 

207 

polarization  in,  200,  301 
products  of,  207 

appearance      at,      elec- 
trodes,  200 
secondary,  208 
uses,  300 
of  dilated  blood-vessels  in  skin 

of  nose,  410 
of  pases,  044 
of  li.iuids.  (544 
of  solids,  (144 
of  water,  218 

platinum  electrodes  for,  297 
product.-  of,  248,  207 
theories  of,  2.13 
Clausius',  2.13 
Grotthuss',  2.13 
urethral,  high-frequency  (air- 
rent  after,  .ls(> 
voltage  for,  2.10.  2.11 
Electrolyte,  s2,  2r>l,  2.13 
body  as,  2.1s 

for  .r-ray  interrupter,  721 
ioni/ed  'iias  as,  (144 
ion>  in,  velocity  of,  2(11 
jelly.  2(11 

outside     battery,     passage     of 
current     through,     teniper- 
ature  changes,  2(i."> 
oxidation   of   positive   ion   in, 

2.10 

pa -.-age  of  metal  ions  into,  2.10 
passing  current  through,  2.10 
plienomena  in,  2.10 
precautions  in   mixing,  0.1 
reduction  of  negative  ion   in, 

2.10 
sulphate  of  copper  as,  01 

testing    for,    2.10 

Electrolytic   action    of   x-ray    in 

causing  erythema,    1  1  1.1 
cell,  anode  of,  plienomena   at, 

cathode    of    phenomena    at, 

2.10 
connected        by        asbestos 

M  rands,   i_>.">7 
countcrelectromotive    force 

of,  2.10 
electrodes     of,     phenomena 

at,  2.10 


Electrolytic  interrupters,  1  1.1 
for  'x-ray  work,  720 

mercury,  care  of,  727 

jet  ,'721 
turbine,  72.1 
principle  of,  720 
rectifiers  for,  723 
Hopiijuet's,  72.1 
Wehnelt,  722,  723 
polarity  of,  721 
lightning  arresters,  227 
medication  in  gonorrhea,  407 
rectifiers,    10(1,   723 

aluminum   cell,   723 
Elect  romagnetic  effects  of  static 

force.   1  13" 

factors  governing,  1 12 
in  hollow  cylinders,  1  13 
in  .-olid  cylinders,  113 
galvanometer,   173 
Snooks',  SC,0 
Weston's,  SIH) 

induction,  electricity  by,  10(1 
in  power-house,  21(1 
static  electricity   from,  .1.1 
interrupter     for     alternating 

current,   S.I  7 

for  triphase  current,  8.17 
vibrating,  141 
wheel  type,  1  13 
system  of  C.  (',.  S.,  171 
waves  in  universal  ether,   115 
Electromagnet  ism,     application 

of,  -1.13.  -l.lt 
effects,  4.14 
Electromagnets,  aeroferric  type, 

110 

armatures  of,  1  12 
ferric  type,  110,  120 
field.  123 

for  powerful  currents,  113 
for    removing    foreign    bodies 

from  eye,  -154 
iron  for,  1 13 

law    of    attraction    of    arma- 
ture, 113 

maximum  efficiency,  111 
non-ferric  type,  110 
physiologic' effects,  4.13 
poles  of,  determination,   100 
power  of,  111 
therapeutic  effects,  4.13 
volume    of,    during    magneti- 
zation,  1  13 

Elect  romechanotherapy,  4s3 
CailTe's    apparatus    for,    4s7, 

4ss,  4s!) 

in   chronic   articular   rheuma- 
tism, 42!) 

Tousey's  apparatus  for,   Isil 
Elect  roinedical  apparatus, 

death      from,      actuated      by 
electric-light    current,   3112 
Electrometer,  717 
capillary,  171 

LipmannV,  174.  17.1 
Einthoven'.s  string.  17.1 
for  measuring  voltage  of  r-ray 

current.  73s 
Nicolai  and  lluth's,  17.1 
quadrant,   101 
Elect  romet  ric  apparat  us. 

Curie's.    1241 
'•hart-.  320 
measurements,  2sO 
Electromotive     force,      2(1,     .10. 


Electron.   17.   Is,  2.13 

.r-ray   in,   7O2 
in  metal-,  vi  locity  of,  2(11 
theory   of  elcctri'  ity,   2.13 

E.Vctropathology,  3.1! 

Elcctrophorus,  30 
charging  of,  30 


ctn 


and  ionix.ation  chamber  for 
mea.-urement  of  radio-ac- 
tivit\-,  12'tS 

current,  of  /eleny,    1211 
for    measuring    x-ra\     il(j-age, 

(113,    11.1s 
PilTard's,  121.1 
static,   1211,    12  t.l 
to   test    radio-activitv,    12)1 
Wulff'.-,  21 

Electnjstatic  capacits'  of  gutta- 
percha,   22.1 
testing,  23-1 
induction,  .11 
system  of  C.  (.',.  S.,   170 
voltmeter,  217 

for  x-ray  current,  73s 
Elect  rot  herapeutic      apparatus, 
absein'c        of        pathologic 
effect.-,   37.1 
applications,     amperage     for, 

204,  20.1 

voltage  for,  204,  20.1 
bath-tub.  438 
table,  Tousey's,    445 
uses  of  heat  generated  by  re- 
sistance, 2U2 

Electrotherapy,  burns  in,  378 
experiments,  378 
prevention,  380 
condensers  for,  300,  40.5 
definition,  \, 
dynamo  for,  1211 

'  machine  for,  40.1 
examples  of  faradic,  422 
galvanic,  422 
sinusoidal,  -122 
Elect  rot  onus.  2s2 
anesthetics  and,  283 
conductivity  theory  of,  28.1 
currents  of,  282 
direction,  2S2 

effects  of,  at  various  dis- 
tances, 283 

Hermann's  theory,  2SH 
modifications  of,  2s3 
nerve  as  cored  conductor  and, 

2  S.I 
nervous    conductibility    and, 

284 

excitability  and.  2S.3,  281 
physiologic  effects  of,   2s3 
polarization  theory,  2stl 
po-itive  after-current  of,  28.3 
theories  of.   2-S.l 
Elephantiasis,  galvanic  current 

for.   127 
Elongation     of     muscle,     reflex, 

3-17 
Emanation,    radium,    collection 

of,   11.11 

Emanatorium,    amount     of    ra- 
dium   required    tor   treatment 
in    12(17 
Embryo,     effect      of     x-ray     on, 

1 1 :-;  i ,  n  33 

Empyema    of    antriim.    radiog- 
raphy   of,     '.i.ll,     o:>2,     OtiS, 
!is_'   osi; 
of  ethmoid  cells,  radiography 

in,  !is( 

of  lung,  radiography  of,   1013 
Emul.-ion  of  bismuth, ''.MM 
Knallaxatone    current.    4v.l 

apparatus  for.  4VI 
Endodiascopr,  771 

therapeutic  u-e,  772 
Endoin(>tritis,  hemorrhagic, 

zinc   cataph.,r.-i-   for.    (iis 
En<los,.opes,   ll.ls 
Endothelioma,  radium  in.   1271. 


INDEX 


Energy,  kinetic.   171 

Erysipelas,  red  light  for,  tlSd 

Exophthalmic       goiter,      death 

potential,    171 

static  breeze  for,  7:i 

after  r-rav  treatment  of, 

English  mca.-urc,  metric  equiv- 

Krvthema do.-e  of  hard-  r-ravs, 

11  US 

alents,  2L'S 

11(10 

diathermy  for,  ti:i7 

Enterocolitis,      electricity      for, 

of  r-ray   at   various   radio- 

electricity  for,  .,20 

i.;i.  i:w 

graphic  strengths,  1  1(12 

high-frequency  current  for, 

Enteropto.sis,  r-ray   findings  in, 

in    ordinary    therapeutic 

.",21,    11HS 

lOL'.'i 

strength,  1  1(12 

radium,  in   127S 

Envelope-,     effects     on     plates, 

from  radium  rays,  12.",7,  12(11 

r-ray   for,  .",21 

S1K-J 

from  ultraviolet   rav,  (isl 

Exostosis  of  bone,  radiography 

for  plates,  Ml.  si.', 

from  r-ray,   1  l.'-il,   1137 

of,   1  HIS 

Eo.-in     injections    before    r-ray 

elcctrolvtic    action    of    rav 

Exploring    electrode,    Tousey's, 

exposure,    12:>"> 

and,  'ill.", 

4  .V.  1 

to  seii-:bilize  tissues  to  light, 

Krythemat  odes,  high-frequeney 

Kxposure,  duration  of,  sll 

(Is  2 

current   for,   (121 

with       induction-coil       and 

Epl,  Title  sellslbl  1  It  V,  -P.'., 

-t  imulatioii  and.    Kill 

Ervt  hroc\  tes,  effect  of  r-ra\'  on, 

iin 

gas-filled   t  ubc,   Sll 
with  transformer,  Si  2 

Epididvmiti.-,  acute,  diathermy 

Erythromelalgia,    galvanic    cur- 

holders for  films,  S10 

for,  H.S7 

rent   for,  -127 

table    for    Hontgen-rav    ther- 

diathermy for.  d/!7 

Erythropsia      from      ultraviolet 

apy,  1  HIS 

high-fre.  iiieiicy     current     for, 

rav,  (is:-! 

radiographic,           Tousey's, 

.->V'! 

Erythro.-in        for       sensibili,:ing 

S90-902 

r-ra\   for,  ",s:i 
Epilation,   diathermy  for,   doS 

tissues  to  light,  (isl 
Eseuhn  with  r-ray,   l'2'M 

I-!xtemporize<l  pole  deteclor.  212 
Exten.-ibilitv  of  paraUxed  mus- 

1- pilep.-\  .  electricity  for,  .",1^ 

Esophagus,     com     in,     n  moval, 

cle,  :•;:« 

high-treqiiency     curient      for, 

!lc.  11 

l-.xternal  electrodes,  :;s(l 

.V.I] 

dilatation  of,  spindle-shaped, 

sphincter    ol    urethra,    spasm 

radium  in.   127s 

radiography  of,  11114 

of.  electricity  for,    IMO 

r-rav  for    r>ls    ,VU 

Extra  ravs    7111        See  al-o  .s'»  r- 

Epileptiform    convulsions    from 

99-! 

cortical  stimulation,  .'i.'l'.l 

foreign  bodies  in,  localization. 

1  'x!  ra-uterine    jiregnaiK'y,    radi- 

Epiphyseal   injurv    at    shoulder, 

i  ji  i  1      '  t'  r  '     '|l  IS     'I'  1  1 

ographv  in.    10(17 

radiography  "of  ,   101C, 

radiography     of,     with     tube 

Extremities,  lower,  fluorosoopy 

line  i  'I    hand,    radiography  of, 

behind,   1004 

of,    10(iS 

1  11)1 

stcno.-is     of,     elcctricitv     for, 

radiography  of,  lOHS 

Epithelioma,       alcoholism       in, 

i:U) 

radiography  of,  bromid  paper 

1210 

electrolysis  for,    121 

for,   Mill 

Hat  surface  forms,  1211 

from      mediastinal     tumor, 

exposure  for,  S12 

fulguration  tor,  .">lil,  ."ili:-! 

radiography   of,   I'll.', 

UJiper.    congenital    le.-ions    of. 

tunirating,  radium  for,   1273 

radiography  of,  !i!i"> 

radiographv  of,   lO'.l.'i 

high-fre<|ueticv      current      tor, 

Ether,     nervous     conductibilit  v 

fluoros.-opy  of,   10S(i 

(121,    1210 

and,  :i42 

fractures  of,  railioscopy  of. 

of  che-t,  r-ray  in.   122.,.   1227 

Ethmoid     cells,     empyema     of, 

101  IS 

of  ear.  r-ray  in.   122.', 

radiographv   in.   Msl 

radiography  of,  10SC, 

of  eyelid,  r-ray  in,    12H1 

radiography    of,    U7(),    HM, 

Svhdnbcrg's  compression 

of  face,  .r-ray  in,    121:,,    122.",, 

'.IS.',,    I'Sli 

cylinder  in,  lO'.'l 

1  22  1 
i  if  '.  >ret,ead  and  nose,  radium 

a  nt  i  Topo-t  erior  ,  .1  1  0,   'SI, 

for,  4:',d 

for.    1211 

lateral,  list,  '.IS.', 

elect  rodiannosis  in,  :ili:5 

•  1  pa'ate.  r-ray  in.  121.", 

]''.u-tachian     tube,     catarrh     of, 

high-frequency  current  for, 

ills 

of    inner    canthu-.    r-rav    in, 

cataphoresis  for,    10.", 

luminosity  test  in,  :*!)! 

1212 

Evaporation    of    water,    electric 

r.ai  lium  in,   1  2dl 

of  lip.  r-ray  in,  12Ui 

charge  and,  (14."> 

effect-  of  lightning-stroke  on, 

ol   nipple.  r-ra\    in,   12i:i 

Examination,     ultra  microscopic 

ds:i 

of  ii,,.-e,  r-rav  in.   121  1,   121.", 

stimulation      of      nerve-liber 

of  radium  on,   12(11 

nl  orbit,  r-ray  in.   121'i.   127.", 

under.  :«1 

of  ultraviolet    rav  on,  ds2 

nl   pan  i!  I'  1  regii  ,n,  radium  lor. 

Excitability   condenser,  .'Jsll 

of  r-ray  on,  1  WS 

1271 

degree  of,  :;:•;  i 

electric  current.-  in,  2dS 

of  peni-,  r-rav  in.   1217 

tatadic,  :jMl 

lixalion  of,  for  Dixon'-  local- 

i idium  in,    1271 

galvanic',  :{Mi 

izing  method,  I'll,  '.'i:i 

irn  nee  after  exci-ion,  1  2O'.i 

law  of,  :;i.-, 

foreign  bodies  in,  localization 

.  •  idium  for,   1271 

mii-ciilar,  nature  of.  :i:il 

of,  111  IS 

I-',    i  Hi.',,    120'( 

ner\'ou-,     alter     transplanta- 

radiography of,  1'OS 

-tic    before,     1210 

tion.  :',lf> 

muscles,  movements  of,  under 

'    |,l  1    ',1     /.iliC    be),,  re,      1210 

at  different   parts,  .'ill! 

corl  ical   ,-timu  at  ion,   li  10 

do-age.    7011 

cold  and,  :;i:; 

pal-ie-  of,    171 

,gic  change-,    1210 

elect  rot  on  I!.-  and.  2s:{,  2M 

ne|-\  e  of  read  ion   of,    HIS 

•  pic    change-,     12lo 

faradic,   Pio 

radiography    of,    alter    injury 

lapli    re-i      for,    Io7 

anomalies  of,   Kil 

fat  iL'Ue  and.  '•',  \'.\ 

seei  itn  larv  react  ion  i  ,1  .  M'.'  1 

•  .   1  27  1 

galvanic,    1.1s.    Kil 

steel  part  ides  in,  elect  romag- 

1                     i!      lion      metho.l      ol 

heal    and.  '.',W 

ni  1  ic  extract  ion   of,    1",  1 

•       oltage,    111.-, 

inlluence  of  drug-  on,  :!12 

Eyeball,  diameter  of,  !M."i 

'!,.  t  hod     .,:     mca  — 

nature  of,  :{:;! 

pet  fora  t  ion     of,     radiography 

'     Ige        pli', 

t  racl  ion  and.  .'!  t:i 

for,  Mid 

Erb                                      -      '       ItiJ 

ol    !  cart    in   lock-jaw,   :i.",1 

[iroti-d  ion     of,     from     r-ray, 

; 

of    motor    nerve-,    variations 

1  Kill,   1  1  10 

:       '  ' 

in.  :;12 

Eyelashes,    effect    of    r-ray    on, 

' 

ot    -pina  1   cord  ,   Mil 
Wei     '-  law  of,  :U.'i 

Eyelids,    cancer    of,    r-ray    for, 

.•  •  •   .     ' 

1  ,\'  itomolol    effect  of  -tat  1C  elee- 

effect-   on    eve,    1  l.'i'.l 

.  :  i  :  . 

Iricit  \  .  7:; 

epithelioma  of,  r-ra\   in.   1  21d 

.V_'.-| 

i    •.-..•      •  .   faradic,    Id! 

I'-  -.   17!                                                               galvanic,    Kil 

I-'  U'l.,   epithelioma   of,  r-rav   in, 

1               ,„                     :  d        -•"                                                '  lei  —  ler    degree    ot,    f.Hl 

121.!,    122.",.    1227 

1  _'.'  1                       nervi  m-.     inlluence     of     circii- 

sinu-e-    ot,    pneumatic,    fluo- 

rrent    lor,    '•  _'d                            lation  on,  :{]:; 

ro-.opy  of,  '.Hill 

12!  »7 


Face,  sinu.-es  of.  pneumatic, 
radiographs'  of,  diagnostic 
value,  '.Mid  ' 

Facial  nerve,   branches  of,  test- 
ing of,    173 

le.-ion  \\  ithin  aqueduct,  473 
parah.-is  of,    172 
alcoholic,   171 
bilateral,   171 
diptheria,    171 
elect  ricity  in,    172 
herpes  and.  471 
involvement       of       sixth 

nerve,   171 

lesion   within   pons,    1 ,  I 
otitic,   171 
reaction    of   degeneration 

in.  473 

without      taste     involve- 
ment, but  loss  of  hear- 
ing,  (71 
stimulation      of,      for      dry 

otitis  media,    131 
trunk  of,  stimulation,  3S.s 
netiralgia,  electricity  for,  .~>01, 


high-frequency  current  for, 

.V.I3 
radiography   in,   diagnostic 

value,  907 
radium  in,  127S 
ultraviolet  ray  in,  1193 
j-ray  in,   1  Id2 
paralysis,  static  wave;  current 

tor,  473 

Factor,  power,  7.">S 
Fading   of   image  during  devel- 
opment, s.s7 
Fahrenheit        and       Centigrade 

Fallopian     tubes,     <  Midin     and 
I )' Ar.-onval  combined  method 
for.  43li 
Farad,   Id.   172 
Faraday,  2ol,  2.V2 
Faraday's  laws,  2.'>1 
Faradic     brush    electrode,     3>3, 

MS  1 
coil,   131,   1  Id 

Helmholtx,  l.-),s,  I.V.I 
interrupter  for,  l.VS 
interruptions  in  current, 

ion 

nature  of  current,  IfiO 
ordinary  arrangement,  1-Vs, 

I.V.I 

j)rimary  waves  of,  1(10 
rapid   interruptions   in    pri- 

in,   Iti'l) 
source    of    imperfection    in, 

i.vs 

with    Wanner    hammer    in- 
terrupter,   I  .Vs.    I.V.I 
current      and      vibration      for 
obesity.   tLN 

electrodes  for,  3s() 
for  alopecia,   127 

for  anemia,    I  1  1 
for  anesthesia.    170 
for  bulbar  paralysis,   170 
for  chloroform  s\  tieope,  12'' 
for  constipation,    13  1 
for  cutaneous  gangrene,  127 
for  diarrhea.    IS.' 
for  dry  otitis  media,   13  1 
for     Duchenne-Krb     palsy, 
179 


Faradic  current    for  hemiplegia, 

517 

for  h\  drart  hro.-is,   12U 
for  hysteria,  .V2  i 
for  hy.-teric  aphonia,   !7.~> 

contraetures,  4*3 

paraU.-is,   1S3 
for  ichtiiyosis,   127 
for    incontinence    of    urine, 


for     intermittent     claildica- 

tion,    13d 
for  liche,,,    (L'7 
for  lumbago,  old 
for    motor    disturbances    of 

stomach,    (3D 
for    muscular    contractions, 

11)1) 
for  miisculospiral  paralysis, 

ISO 

for  mya-thenia,  39.') 
for  neurasthenia,  ~S2.~> 
for  neuritis,  .V.I3 
for  obesity,  42s 
for  obstetric  paralysis,  479 
for  ocular  paralysis,    171 
for  paralysis,   100 
for  pemphigus,    127 
for  perforating  ulcer  of  foot, 

(27 

for  poliomyelitis,  "ill? 
for  prurigo,  427 
for     rheumatoid     arthritis, 

426 

for  sciatica,  .~>07,  oOS 
for    secret orv    disturbances 

of  stomach,  430 
for       spasm       of       external 
sphincter  of  urethra,    130 
for     sternomastoid      paral- 

for  stimulation,  33S 

for  stricture  of  esophagus, 

430 
for      testing      branches      of 

facial  nerve,   473 
malignancy    of    lump    in 

breast,    101 

neuromuseiilar      appara- 
tus, IV.) 

sensory  react  ions,    107 
for  torticollis,  old 
for  trape/oid  paraly.-i-,   177 
for      triireminal      neuralgia, 

for  urticaria,   127 

for  \  itiligo,   127 

for  wr\    neck,  ol'.l 

from    lonir    seeondan     coil 

with    iron    core,    strenirth 

of.  Id2 
galvanic  current  wit  h.      See 

general    indications    for    ef- 

fec*s  of,    121 
illilui-ed.  217 

Ledue    curretH     and.    coni- 
pari-on,    Id2.    Id3 

ir  contractions  h\ 
modification-  in  effect-. 
107 

ime    for,     automatic, 

|so 

stimulation  by,   1st 
therapeutic  effects  of,    122, 

12.; 

indications  for,   122.  423 
tn   itn  cut  by,    I.Vs 
•    L'I      oi      mi  asui 
217 

',  ctri.-it\  .  Is 
tinit'i  ni,    Is 

•  •    thi-rapy,    <  xampli  -    of, 
122 


Faradic     excitability     following 
de-t  ruci  ion  of  motor  area 
of  brain,  312 
loss  of,   in   oxalic  acid   poi-- 

oning,  3  12 
exhaustion,    nil 
hyperexcitahility,  39(1,  401 
h\ -po-excitabilit  v      \\ith      gal- 

'  vanic  formula,  3dO 
loss,  40! 

roller  electrode,  3s.'> 
Faradimete:,  _' 1  7 
Faradization     by     rolling     elee- 

Faradogalvanie       current       for 

atonic  dyspepsia,   131 
for  entcroeo'it  i.-,    131 ,    133 
for  facial  paralysis,  472 
for  hemorrhoids,  012 
for  lumbar  sprain.-,    130 
for  menorrhagia,    131 
for   motor   disturbances   of 

for  neurit i-,   ")03 
for  renal  pain,  •">]  1 
rheotome     for     automatic, 

489 

stimulation  hy,  4s.~> 
Tou.-ey's  tech'nic,    l.SO 
Fatigue,    influence    on    contrac- 
tion, 333 

negative    variation    in    nerve 
and,  2SO 

nervous  excitability  and,  313 

reaction  of,  3d2 

resistance    in    muscles,  _static 
electricity  showing,  71 

static  electricity  and,  71 
Fats    in    -tomach,    radiography 

Faure's  aciaimulator,    102 

l-'avus,  x-ray  in.  1  174 

Feet,    radiography    of,    bromid 

paper   for.   s()d 
expo-lire  tor.    M2 
Femur,     neck    of,     fracture    of, 

radiography  of,   lOOs 
ununited.  radiography  in, 

1071 
Fenwick's    phlebolith    catheter. 

10.VS 
Fermillac   and   barium   sulphate 

meal  for  radiography,   102:', 
Ferric  t\  p-  of  magnet,  1  Id,  120 
Ferrie's  ondometer,   "il7 
Fery's  dry  cell,  do 
l-'ctii-,   effect   of  .r-ray  on,   1 131, 

1  133 

radiograph  of,  in  utero,   1007 
Fibrillary    contraction    in    elec- 

troeution,   .V.il.   .V3ii 
Fibrillation  in  heart   from  elec- 
tricity, 3-V2 
l-'ihroids,     uterine,     radium     i'l, 

1277,  127s 
Fibromyoma.    uterine,    Apo-toii 

treatment.   133 
(iau-.-'s       rontgenotherapx 

for,   12H7 

mesothorium  for,   1209 
radium  for,  iL'O'.i 
rontgenothera]\v    for,  Toii- 

se\  '-  teehnic,'  12(17 
Fihrou-      coinlitions.      high-fn- 

•    iMirrent  for,  ">d7 
Fibula,  fracture  of,   Pott's  radi- 
ography of,   107s 
r:nlioL'raph>-   of,    11170,    ](i,  , 

radiography  of,  ll>77 

liznets.    123 

I    •    d-plates    of   static    m: 
31 

Fi:t\  -centimeter      .:--• 


INDEX 


Files,  plate,  893 

Fleming    rectifier    for    high-frp- 

Fluoroscopy  of  heart,  007 

Fihi.L'   bobbin   to   certain   resist- 

quencv  current,  .",30 

of  humerus,  1080 

•     .     -'-'n 

-tandard  cell,  92 

of  knee,  1072 

Film,  xi  ix 

Flexible  contact  diaphragm,  801 

of  leg,   107.") 

arti  facts  on,  M  1 

Flexions     of     uterus,     high-fre- 

or lower  extremities,  lOOx 

celluloid,    inflammability    of. 

quency  current   for,  .">s2 

of  lungs,  000 

810 

Flower-  of  sulphur  in  tinea  cap- 

of  maxillie,  917 

clip,  Tonsey's,  038 

it  is.  11x3 

of  neck,  OSS,  001 

di  nl    ,.    di  v.-liiping    clips    for. 

Fluid    in    sphenoid    cells,    radi- 

of pelvis,   1017 

!H  ;x 

ographs    of.  9x7 

of  pneumatic  sinuses  of  face, 

ili  \  ••1'ipment     <.f,     judging. 

Fluorescence,   nature  of,  0.">3 

972 

930  ' 

nl"  tube.    709 

of     pulmonary      lymphatics, 

duplimed.  910 

Fluorescent  medicines,  behavior 

10OX,    KHIO 

gla-s  mounts  for,  Totisev's, 

of,   1230 

of  radius,   1080,  1090 

911 

bi-ulphate   of    quinin,    1  23."i 

of  shoulder.   1080 

t  ra\    devel,  ipment   fur.  030 

e-culin.  1230 

of  special  parts,  xo.-, 

development  of.  x7ii.  x77 

fiuon-cin,   1230 

of  stomach.   1021 

Fastman      duplitizod      jr-ra\  . 

for  gastrodiaphany,  1230 

of  thigh.  1071 

810 

radiance  from,    1  230 

of  ulna,  10x0,  1099 

•  xposiire   tiolder   for,   xl<) 

slowing  effect,    1230 

of  unempted  teeth,  91S,  010 

file,  xo.; 

with  x-ray,  123.") 

of  upper  extremities,   108(5 

:  '::._-  •  if,  x93 

Fluoresein,  dosage  of,  1  137 

of  ureteral  calculi,   10.V1 

t>  ir  'i'  ntal   •  ;n  lii  igraphy,  tank. 

internallv    to    sen-ibilize    tis- 

of urinary  calculi,   10",4 

.levelo,,ment,  xx(i 

sues  to  liglit,  iixl 

of  wrist,  '1080 

frilling  of,  X'.ID.  x'.il 

radiance  from,    1  137 

prolonged,  X9."> 

horizontal,      radiography      of 

with  x-ray,  123.", 

room  for,  711 

teeth   on,   021 

Fluoroniete'r,  Tousey's,  841 

stereoscopic,  SIS 

ii  -t  ml  me'  ms,  M  1 

Fluorophototrraphy,  803 

technic,  710 

nl  -,  celli:       1.  041 

Fluoro.-cope,   709,   XIK; 

to     differentiate      hematoma 

glas:-,  oil 

attaehn.i-nt   for.    ,  .",0 

from  fracture  of  skull, 

packet-,  ductile.  92:i 

author  opposed   to  u-e  of,   in 

004 

tooth,    overdeveloped,    reduc- 

gastric diagnosis,    1034 

from  hernia  cerebri,  004 

tion  of,  9:iO 

box,  709 

to  estimate  size  of  heart,  1007 

•    ragi    of,  x'i:-; 

in  radiographv  of  foot,  10x0 

to  test  lung  reflex,   101.", 

tank   develi  pn  cut    of,   xxli 

in  renal  radiography,  10.V1 

usefulness,  x9."> 

n  cr,   l'  u-tinan,  x]ii 

care  of,  709 

Flu.-h  receptacle,  2O7 

I    .      ;      h  '  S  ,      '.  '  2  X 

dangerous,   114.") 

Flux,  magnetic,   11.",,   1  19.     See 

•    '  '         :'..    927 

dental.  Tou.-ey'-,  920,  021 

aL-o  Mnamtic  Jinx. 

Filter  and  cellular  Mucky  screen 

deterioration  of,  709 

Focal  infection  of  teeth,  029 

:    rarrcstinKS-ei  '.ndary  ray- 

John-ton.  710 

Fogging,  x79.  SOI 

.      •  issin  -.      C'h'  lice      be- 

magnifying,  Tousev's,  021 

chemic.  S70 

twi  •  :..  x:;l 

operating,  710 

due  to  envelopes,  si  t,  M.", 

fi  ,••  -  ,••  j-ra  •  -    7'ix 

SalviniV,  922 

in  -torage  from  jr-ray,  X93 

Toils'   .  '-.    clo.-e    to    plate    tor 

screen  of,  color,  7O9 

Follicnlitis,  radiutri  in,   1277 

re--ing  -ccondary  rays 

illumination     of,     intensity 

vulva',  electrolysis  for,   120 

fiuoroscopv 

Touscy's  dental,  920,  921 

Food-  tuffs        passing        through 

of,  111  '2 

:      gnifving,  921 

stomach,  radiogr:i]ih\  of,  102x 

gr  i  pi         :.    1  102 

1  luoro.-cop\  .  7MI 

l-'oot,  artel  ies  of,  injected,  radi- 

gl   ph      of.    !  '  19  1 

In  fore   radiograph\    of  frontal 

ograph  of,  112x 

-    -    ::    p,   e.e,:,,   tiiii; 

sinus,   973.   971 

fluoro-copv  of,    K)x(l 

•  •   m  lupus.   1  Ix:-; 

danger  or.  x9.",.    1  1  10 

pertorating  ulcer  of,  high-fre- 

1  ins.  •-!;••  :.   lamp.  017,  MX 

dental,  922.      See  also  Dint'il 

qtiencx-  current  for,  029 

••   .    •        iting,  200 

'  .      ,  <,-„,,,,. 

radioL-iaph\    of,   lllxii 

-  •     /  is.  '.I'M 

ili  nn  :i  tit  is  from,  xo.", 

tuberculosis  ol  b.  ines  of,  radi- 

:         .            •     '    '                   .",  J 

in  brain  tumors,  9O1 

ographv  in,  112x 

i  •     ol.    1121,    1122 

in  carie-,  olx 

ulcer  oi,   perforating,   faradir 

i                               '     .                   *                 •               ,            }  .    -    "]      _]    T-(.(  1  ]   |('  J  Jl'\ 

m  pneumonia,   1O1  I 

current   for,   127 

rn-nt   for.  ol_> 

in  pregnancy,   1  133 

l-'oramen.    a],ieal,    dental     radi- 

:      •  .         bo  n    '  ,v  .    copper  cat- 

in      p:'lmonar\      tuberculosis, 

ography   to  locate,  04s 

KI.-J 

1011 

mental,     in      radiograjihv     ol 

in  softi  iiing  of  ti-fth,  Olx 

lower  bidi.-pid,  01.  "i 

-7     ''  1  x 

01  abdomen,    HH7 

Force,   170 

1  .  ,  ,  .  ,  .  ;  .  f,,r, 

of  juitrum    9x1 

Forearm,  arteries  of,  radiograph 

107  ' 

ol  aorta,   100.", 

of,  1121 

of  che-t,  090 

fluoroscopy   of,    10x0 

•    - 

...  .      ..        .,•.,; 

normal,    1O90 

... 

:     shoulder, 

igiaph\    of,    loxs,    111x9 

1102 

|-"on  ILTI    bod\     in    .  ilian     !  i«l\  , 

• 

bow,    10x0 

radiography    in,  OH1 

•     ;  ••  •  •    current.  211 

ol  fi  10!  .   Inxii 

in      cranium,      localization, 

•  •    t  herapi-ut  i'>, 

-  it   tori  at  in,    lose, 

9(1  1,   9ll."i.   91  Hi 

•    •  .     ••      •          .         n    e-opha- 

radiographv    lor,  0(11 

1                                    r  Dixoi 

'1.  992,  993 

-ti-i  eosci  ,p]c   i  adiograph;. 

.   '  '  i  !  ,   '  *  1  J 
!        • 

..  991 

triangulation   in,  9OO 

i                 :,••-,  o  n 

•    ••   i  -  •     ri    nt  cl;,i  ic)e,    Kixii 

in    e-ophagu-,    localization, 

;           .     .     . 

1   linger-.   1  102 

991.   902 

i.l      hun.eni-,      IOXIJ,      109X, 

in  eye,  radiography  of,  008 

.  •  •  •  • 

in     inic-tin.s,     loi 

•    • 

nl,   !O2x 

• 

n  g,      - 

'.II' 

Hii:, 

ol     lit  a.'  1099 

in  neck,  radiograpl          .   '91 

.  .          .                  ...-,., 
- 

•  •      •    -              :               efore   radiog- 

in     orbit,     radiograph;,     of, 

'  !(  )^ 

'  ,  -     ''/--- 

•         r,f,     pHiri 

1299 


Foreign  body  in  stomach,  local- 

Fracture of  scaphoid   bone,   1111- 

Frontal    sinus,    radiography    of. 

ization,  102S 

united,  radiography  of,  1  100 

with  patient  seated.  O7.'i 

radiography   to   locate,   x<>4 

of     scapula,     fluoroscopv     in, 
1  <  )Sd 

transiliumination  of,  OS] 

rornialtn  in  development,  S'K) 
undiluted,     for    .r-rav     warts. 

radiography  of,   100s 

127 

1111 

of  skull,  fluoroscopy  in,  002 

Figuration,  odl 

Formula    for    "ikonogen-hydro- 

hematoma     of     scalp     and. 

electrodes  for,  5(12,  5fi:', 

(|iiitniiic  developer,   SS2 

fluoroscopv  to  differenti- 

for cancer  of  breast,    ~>W 

for  hvpo,  SSt 

ate,  004 

tor  epithelioma,  5(11,  5(i:( 

tor  M.  (2.  developer.  SM 

hernia  cercbri  and.  fluoros- 

lor  tuberculosis,  5d2 

for  ortol  developer,  SS2 

co))v  to  differentiate,  001 

for  r-ray  dermatitis,  5(12 

for  pyro,  S.7S 

radiographs-   in.   002,   '.Hit 

warts,   1111 

for     pyrocatechin     developer, 

of    tarsal    hones,    radiograph  v 

Hart's  electrode  for,  502 

SS2 

of,    lOSt,    l()s.-, 

Tousey's    electrode    for,    5(12, 

for  tank  developing,  SSO 

of  tibia,    107"),    107(1,    1077 

5(i:{ 

for  tropical  developers,  SOO 

of  tooth,   radiography  of.  050 

Functional  angle  in  pulmonary 

intensifying,  sso 

of  ulna,  radiography  in,   1000 

tuberculosis,    10M 

Forschhainnier's      formula      for 

of  wrist,  radiography  of,  1000, 

Fungating     warts,     magnesium 

sensibilizing   tissues   to   light, 

1  100 

cataphore-is  for,    10(1 

(IS  2 

united,    radiographic   appear- 

l-'uniciilitis,      acute,     diathermy 

Fort's     linear     electrolysis     for 

'  ances  after,   1  101 

for,  (1M7 

esophageal       stricture. 

Frame   for   holding   plate   in    an 

radiant  liglit  and  heat  for,  51(1 

420 

inclined    po.-ition    for    gastro- 

Furunculosis,    cataphoresis     in, 

for  urethral  stricture,  420 

intestinal    radiography-,     10:i!i 

US 

Four-cell  bath,  connections  tor, 

Franklin   as   unit    of   density    ot 

galvanic  current   for,  4^7 

444 

static  charges,  70 

high-frequency     current      for, 

for  muscular  atrophy,  44") 

electroscope      for      measuring 

(121,  (127 

for  Ka\  naud's  disease,  44.1 

x-ray  dosage,   1  15S 

-tatic  electricit\-  for,  78,  427 

for  rlieuniat  ism,  444 

Frank'inic  bath,  (10 

Fu-e  wires,  200 

Sclmee's,  4  1  1 

Freckle.-,   red  light   tor,  (1S(1 

Fused  salts,  conduction  by,  2(11 

sinusoidal,  4  45 

Freezing    mixture    for    moisture 

Fusing-]>oints  of  alloys,  200 

I-'ourth   nerve,  paralysis  of,  471 

in  static  machine,   10 

of  metals,  200 

Fox-tail  brush  discharge,  4S 

Freezing-point  of  solution-,  2'itl, 

(•"Factional  volt  selector,  dental, 

2*17 

for  cataphoresis,  404 

Friction  spark,  (1(1 

GAO-XKHK'S  plate-holder,  S]5 

Fracture,    callus    after,    radiog- 

type of  static   machine,   -im- 

(laitTe's     a[>paratus     for     using 

raphy  of,  1104 

'  pie,  31 

alternating    current    Trans- 

Colics', radiography  of,  lOS'.l, 

Frictional     electricity,     is,     p.*. 

former  for  x-ray  work,  1(17, 

1000,   1000 

See  also  Stutir  ilidr^-iti/. 

Ids 

Tousov's     positions     for. 

resistance,  220 

arrangement  of  ventril  tubes, 

1090 

sourc(>s  of  static  electricity,  55 

7ss 

functional  results  after,   1104 

Friedlander       shield       as      dia- 

contraction   apparatus,    4SS 

of    acetalmlum,     radiography 

phragm.  701 

hot-wire  galvanometer,  SdO 

of,  1070 

water-colored  x-ray  tube,  7d3, 

method    of    measuring    .r-rav 

of     anti-rosiipcrior     s])ine     of 

7(14 

dosage,    1155 

ilium,  radiography  in,  1071 

Frilling  of  film,  SOO,  SO  1 

transformer,  748 

of     carpu.-,     radiography     of, 

Frimaudeau's  interrupter,    102 

outfit     for     high-frequency 

1000 

Frog's  legs,  contract  inn  of,  (!al- 

work,  5i:-; 

of   cervical    vertebra",   radiog- 

vani's experiment,  M14 

principle  of,  744 

raphy,  of  001 

Frontal    sinus,    fluoroscopy    of, 

safety-valve  of,  715 

of     clavicle,     iluoroscopy     in. 

b  'fore         radiography, 

Call-stones,      radiography      of, 

lO.Sd 

O7.'i  -07(1 

inis.             S«>e      a  so      biliary 

of     coccyx,     radiography     of, 

danger  in,  071,  07.~> 

calculi. 

10117  ' 

liigh-friMiuency    (  urrent    to, 

Calvanie  cell,  S2.      See  also  Vol- 

of      fibula,     radiography      of, 

1120 

tiiic  r.ll. 

107.").  1(17(1,   1077 

normal,  OsO 

cell-baths,   14:-!.  415 

of      finders,      fluoroscopv      of. 

of  empty  skull,  OSO,  '.M 

tor  chorea,  510 

1102 

radiography  of,  OHO 

tor    locomotor   ataxia,    443, 

radiography  of,   1  102 

anteroposterior,  071 

5  1  5 

ot    humcni-,    iluoro-copv    in. 

dUiphragtn  for,  07S 

for  neuritis,    1  15 

Ilisi;,   100s 

distance     from     tube     to 

current,    Benedikt's    applica- 

radiography of,   lOOs 

pate,  07H 

tion,  5(10 

of     inferior     maxilla,     radiog- 

fluo-oscopy  before,   07:;- 

electrode-  for,  ,'isO,  .'-',x:-J 

raphy  in.  Ols 

07(1 

expectorant   effect,    134 

01  li.uer  ja\\  ,  radiography  of, 

lateral,  0(10 

faradic  current   with,  stim- 

0(15 

plast  ic,  ssil 

ulation  by,    ls.5 

ot    mctacarpal    bones,   radiog- 
raphy in,   1  100 

position  for,  07:!,  071 

ftir  acute  gout.   125 
for  anthrax.    42s 

of    metafarsa!    bones,    radioLT- 

of  operator  in,  07s 

for  atonic  dyspepsia,   431 

raphy  in,   lUv~, 

relat  ive  po-itioll  of  tube, 

for  blennorrhagic  arthritis, 

of  neck  of  feiuiir,  radiography 

)i  ate,      and      iiat  ient  's 

121 

in,  Kins 

in  ad,  072 

for  bronchitis,  43  i 

ununited,      ra  diographv 

stereoscopic,  i>7."> 

tor  broni-hopne  unonia.   134 

of,   In71 

tei-hnic,  0,  s 

for  bulbar  para  ;.  -is.   17(1 

ot    odontoid    f)roeess,    radiog- 

time ,  [  exposure,  07S 

fi  ir    C(  rvici  ibrachial    neural- 

raphy of.  001 

Toll-ey's    device    tor    po- 

gia.   50(1 

ot    i  ilecranon    process  c  .;'   ulna. 

Mnot;inir  ,r-ra\    tube 

for    cicatrices    inter    b'.irn.-, 

radii  igraph  v   in,    1OOO 

for    'dl 

127 

of     patella,     radioLTapln      in, 

head  trnueto  indicate 

fi  if  con.stipatioi  .  -431 

107  1 

m  ei  1  i  a  n  o  '  :  i  n  •     '  '  7  * 

in  Iieurasthenia,  52'1 

unio,,  .  shown     bv     radiog- 

!at, ral    plat.  '-holder  in, 

:•  >r  ci  iiit  u-ion-.  42d 

raph;,  .    H)7:. 

07  1 

for  cutaneou-  gangrene.  ;27 

oi    phlanges    of    foot,    radiog- 

t TI   ::'  illg    '  it     plate,    O7'l 

for  deafness.   1M1 

raph;,     in,    Ins.", 

v  a  1  ii  i  •,  07'.' 

ti  'i-  dr\-  otitis  ::.    dia,    ',  •    ' 

of      hand,      tluoroscopy      of. 

\\i:  i    pati,  nt     lying    face 

for     Duchenne-Krl      p     -    . 

!  1  1  12 

do-A,,.  07H,  071 

170 

radi..grap!.\    of,    1  1O2 

fare   Ul>,   '.'71 

for     Dupti;.  tri'ti's         :."      - 

dt  radius,  radiographs  ot,  b  100 

on  -id,-,  070 

tion,   12ti 

INDKX 


•••••"     r  (    ;'.;'.--:!->•-, 

(ialvaii!'1    riirri-nT     lot    tubotvm- 

danniia-radii;  m  ra\>.  1211,  1  JU 

!.;i 

paiiiti.-,   i:-;t 

ab-orption     b\-     ua>e>    and 

:    •   -       liyi      si  -.    l_'o 

for  nr:  ii-aria,    tL'7 

liyht      and      lieavv     .-ub- 

fin        •:.    :•    i,    i_'7 

fi  r  \  ii  iliL-i  '.   1_'7 

stances,   !J7,:; 

for  eczema,   (_', 

for  \\  nlfi-'-  i-rainp.  .",  I'i 

origin  of,   ]_M:-! 

for  electric  baths.  1  1-'.      See 

jimiTal    inihi-at  ions    for    rf- 

])roilneed     bv     alj.'na     ravs, 

.    ' 

fci-tr-  of,    !-'t 

!  _'  1  _' 

lira\'\  ,    lor    roiiMipation    of 

secondary,  l.'ol 

for  '  lephantiasis,    1-7 

IH'i:ra~!  hi'iiia.  .">_'i'i 

produced    bv    beta    ra\'s, 

•    •    1                          -  .-.    17'.i 

inti-rruptcil,    Im-a!   anc-tln'- 

1  1'.'.  1 

for  i-r>>ip.-'ia.-,    L'7 

~ia  from,  7,:;n 

(ianclion-eel!-    of    anterior   i-or- 

fc  ir  er\  tiiT'  imelai!_-ia,    1_'7 

for    lii-oiii-hial    a-th- 

nua  oj  -pinal  cord,  electricity 

fur     exophthalmic     Boiler. 

ina.  .".:•!(  I 

from.  L'lis 

o_'l  ' 

fi  ir   i;,!:::  ;i  ini-,   o-'.i  > 

(  laiii-'ri  nc,       ciitanei  ills,       slat  ic 

f(,r    facia!    neurahna,    ,">()!, 

iiioilififil   li\-   i-onili-iiM-r.-   in 

elect  rieit\-   for,  4J7 

.".1  !.". 

parallel,  1st 

diabetic,      roonator       etlluve 

.,  .-  ,'•  -is    17-' 

rlit'otoint1     I<ii',     ;  i  u  t  '  '  1  1  1  ;  1  1  1  1  '  , 

'  o!  .    7*  i 

fur  furu'nculosi-,  4_>s 

4S'J 

svmmetric,    iralvanic    cnrretit 

for     traiiL'reiic.     .-  \-iniin-tric, 

>tiinulatioii   by,    1M 

for,   !L'7 

t_'7 

tlicra])c-utii-   clTci-t^  of.    }.'_', 

Oarment>.  j--ra\-  proof,  s(l_> 

:    •   ira.-tri     ilisi  a.-cs,    1-1 

l.'.'i 

tias-eiifrine,  iKnan.o  driven  bv, 

fur  Hi  iin  irrheal  rheumatism, 

to    pneunifipar-trir   nerve  in 

i_'i; 

}J1 

L'a-trir  diseases,   tMl 

Clases,  elect  roly.«is  of,  IJ14 

for     headache    of     nervous 

in    neurar-tiienia,     '>->>, 

ioni/ation    of,    iil_'.      Sec    al-o 

dyspepsia.  .-,:>ti 

."i_'7 

]nni:'it'"n  "''  '.,"•'  ft. 

for  hemipli  iria.  ~>17 

trratnii-nt  l>\-.  44ti 

ion>  in,  velocity,  L'lil 

•    -   :..•;..-/  .-t.  •.  i-. 

electrotherapy,    examples   of, 

transmission      of     electricity 

for  hydrarthrosis,   l_v. 

I.'.' 

through,      ])he!iomena      of. 

for  h'vpiTpla.-tic  utitis,   4:?4 

exritahility,  .'jss 

til_' 

for  hysteria.  5L'] 

anonia!ie>  of,   !iil 

Clas-fille.l       IJi'.nttren-ray     tub". 

for    hysteric    contractures, 

exhau-tion.  4iil 

advantage  of,  7^'. 

4s:; 

formula,       laraili'-       liy;>o-ex- 

.-ea^onintr,  .s:5!l 

paralysi-s    Iv'i 

citahilitv  with.  :-','.n  ' 

\\  ith  iinchantred  vacuum, 

for  i'-htin  ,-.-.    !_'7 

hyperexeit'ahility,  :i'M 

tnillainpcre.-.  and  back- 

for impotence  in  neurasthe- 

hypo-excitability    with     nor- 

up in,  relat  ion  bet  w  ci-n, 

nia,  .">:>.-> 

mal  formula,  faradic  hyjio- 

s:il 

!L".I 

inver.-ion,  Jiil 

-pi  i-d  of,  MIS' 

for  infantile  i-cn-hra!  palsy, 

los.--,  4f,l 

Gastric.      See  Slmwirh. 

.M  7 

[iiiiM-iihir  valve,  ^'7M 

Gastrodia])haiiy,          tluore-cent 

for  it.'hiiiL'  of  lichen  nihcr, 

,-i-ali-    of    IK  uri  unuscular    <-x- 

media  for,  1  j:C> 

tl'7 

citability,  4.,f, 

(  la  -tro-  intestinal     ra<lio(rra]iliy, 

for  keloid,   iJ7 

Oalvani's  frou  ex[)eriinc'iit,  ol  1 

Tousey's  technic.  ]n:',:> 

for  lichen,  4_'7 

Clalvai  autery,  JO:-; 

CJa.stroptosis,     tadiourapliy     in. 

for  !•  icomotor  ataxia,   ~>l~> 

blade>,  :;s:-;,  :iM 

K  ):{(),  1  <i:;_' 

for  lumbago,  ."'•.". 

handles  tor,  MM 

iindincs  in,  ](l_':i 

•  a,    l-'t. 

(  lalvanometer,  ii.s4 

f  laiiue-  for  wire,  21  s 

for  miisculi  spiral  paralv.-i-. 

acctira-y  of,  limits,  l'.H 

CJiiuss's      riint^enotlicrapy      for 

Isli 

coil,  d'Ar-onvaTr-.    I'.IJ 

uterine  tibromyiima, 

foi  ::,-.'   .-:-  •  mi'oidcs,   1:'7 

of       refli-i'tioll       of. 

1  _'i  )7 

fi>!    ni    ,••.-•!.•:.!•!.    ~i'2~i,   "i_'ii 

!'>:•; 

(lermatit  i-  in,   1  L'I  I'.i 

cephalic    .W, 

in.-uiat  inii      \-ariii.-li'-.-      lor, 

iieero-i-  oi  inte.-t  ine  in, 

:    •    tn    irii  -.  :,MH 

L'lL' 

1  _'(M  1 

:    •      •     -  •    .   tL's 

(l'Ar>onv:ir.-      movalile      coil, 

tn     tment  1  ubi  .   1  Ji  's 

:    •   oli-ti-fri''  para!y.-is,  47'.i 

!'!.' 

(lei.--  ler    decree    ol    exhaustion. 

pi    -   '.   1J7 

i  lei-troina^'iietic,  17:> 

1  i  1  1  i 

for  p         IMVI     ti-,  .'.  !  1 

Sn  .  ;  -'.  siiii 

tub.  s,  tin; 

i  .    oil 

\VeMo.r-,    vt',0 

as  vacuum  electrodes,  ti.".  1 

:    i   pi  irii;  .,    1J7 

(  laifTe'-    hot-«  ire.    Mill 

effect   o;   iiirht  on  nciuhbor- 

:    -    i:       -      .  ,      .11-   i-i..    l_"i 

hot   uin  .   171,  -ii(j 

iiiL'  (lases,  Ii7i; 

:    •    -:.     i!      '.    •    .    IJii 

mirror,  I'm 

;        -.-..!-.   eharned  particles 

:    r  roatini:    -    •   .r-,    1.11 

needle,    17:i 

in,  7l:i 

•     in  .  •  ,  •  -  .  :,  1  1  j 

di  \  iation-  in.    UK) 

showing     cathode     stream, 

:    •          1  1  i  i        ."  i  •  7  ,  .",i  i  -. 

n  -i-taiie,    ,,:,   171 

I',.",] 

roii.-rii.a,    1  J''. 

shunt    n-i-tiinre   and,   rela- 

-pccial form-,  ii..l 

tion.    |--x,    Is'.) 

(ielatine.     demineralized,     elec- 

. 

•     -                         Ii,  _'n:', 

,'  '•t'r'i'e'd'ialy-is,  L'.")S 

'    '        -;.'!-•:         o!        i  •  \  1  1  •  r  !    1  1 

-ill!    .       I'.'l 

conduct  ivity  of,  L'.'is 

•  •   -    •.  :     •    .•••:•..  i:;n 

.  17:; 

.    .  -I  ropositive.  _'.".-. 

•     .    !.'..! 

Snool       .        tn.i     iirni  tic,   Slid 

(  1.  m  latintr     electricity,     m<  m- 

toi.l     palaK  - 

fan-."  nt,   I'.'H 

.-:.   Is 

;  77 

liven.—  of.   I'M 

(  lelicrator,       elect  ric,       Jioitabli-, 

•  .  .,.,'• 

'I  In  :    p  onV  i:  irror.   I'.K) 

foi   ..--:  iv    vvi  .;  k,  T':'i'i 

•    • 

to  men     in     nterii1'    re-  -ttince 

motor,     direct      current,     lor 

:                       -       -•••.",;] 

ol    VO    lair    eell,    '.Mi 
vo'tai 

to    r.  'ii;cc    t  iol  !e\  -car    eur- 

i.  lit.  L'l.'i 

two-Ill  .  die.     171 

unfluctuat  mi'      lii)'li-|.otciit  ial 

• 

U  i  -ton'-          i  l.-etto!     iirin  ti'  . 

•    t.ani   r-iirrent,  7o" 

•>!,!  1 

,  lllllectilied  tl     •      '     1 

;  ,  ,  7 

<  ,..-.::  o...  n    •   .••  .          eli-'trode- 

a-'.  7  i:i 

• 

;,  ,,    ;;s:; 

i  ..  •       ilate  iranu'Hon,   inflan  ma- 

'.7  • 

•    •    •    .  .  -  -  ; 

•      •            17  1 

• 

'•  1' 

(I,.,,,,                  ....                   ,;,.... 

.'i  •  : 

•    •      •    •      .   1  1  ii 

••',.-;,,)'••     ciii  "  nt    foi  ,   .".v; 

• 

.     .        , 

i          - 

1  :                  ••;.,_•_' 

rent   lor,  ,",s:i 

INDKX 


flenito-urinary          tuberculosis, 

filass    \-acutim     electrodes    with 

Grounded  body,  induction  in,  23 

hinh-frequency     current      tor, 

d'Arsonval     current,     effects, 

(  Iroundirm     a     Coolidj/e     r-ray 

5S  1 

.">71 

tilbr-,  7s_' 

(  Inn;    valu'iim,    rai  lit  >trraphy    of, 

Glossolabial  paralysis,    17.'. 

one-  ],o!e  oi  a  batten  ,  :;i,l 

1H7.". 

(;loss\-    velox    paper    lor    dental 

of  a  step-down   Iran-for- 

( lerman  hiirh-frequcncy  appara- 

radiographs, '.i-»:5 

mer,  'Hi.") 

tus,    552 

(Hove.-,     protective,     in     dental 

static   machine,  :j(il 

s-i'.vcr,  fusitifr-point  of,  20'.  i 

radioj-'raphy,  !'_'."> 

Grove  cell,  '.H 

win-,  resistance  of,  -1'.',  2:5:5 

j--ra\  -proof,  Sl)2 

(luillemmot  spirals,   ~>~>~> 

(  ,i  station,  radioL'raphv  in,   1  1  .'i  1 

(How    discharge    of    static    elec- 

double,  autoconduction  by. 

Gilbert,   12ii 

tri.-i:  \  ,  .".. 

•  ).>.! 

Gland-.  elYect  of  electricity,  .'502 

(  Hyceriii,   nidiferous,   12(i(i 

hifih-tension  current-  from, 

(  llandular  secretions,  static  elec- 

Ciiiter,   exophthalmic,   hi^h-fre- 

.").")."> 

tricity  and,  ,"1 

qilenc\    current  in,   ll'.Mi- 

technic    in    arterial    hyperten- 

Glass     electrodes      filled      with 

1  l'.i>, 

sion,   '>'>'•-> 

liquid.   I!'!' 

radium,  in   1U7S 

Guillox's  stereodioKraphy  with- 

in  hij_'h-frequeiic\    apparatus, 

r-ra\    in,    1  I'.ni 

out   stereoscope,   sis 

22(1 

ioiiiu  anaphoresis  for,   100 

techni<-    for    cataphon-sis    for 

insulators,    resistance   of.    221 

x-ray  in,     I'.i. 

trout,   IDS, 

mount  for  dental   films,   Tou- 

Cioldber-'s  law,  (l.sl) 

.r-ray  tube,  7715 

se\  '.-.  Mil 

Coldstein's    kanalst  rahlen,    712 

Gumma    of    bone,    radiojrraphv 

plates,    force    required    to    ro- 

Goljri   method    in   studyiii}:   cell 

of,   1  1  in 

tate.  .">(! 

chaiiL'cv-     from     elect  roi-iit  ion, 

r-ray  in,  117!) 

tor  -tat  ic  machine,  .'51  ,   37 

.-,;;;; 

Gums,"  electrodes  for,  (117 

tube.-    for   radium    treatment, 

Clonorrhea,  diathermy   for,   (io7 

epitheliuma  of,  x-ray  in,  1215 

1  _'!  i  I 

lo.-s  of  vacuum  of.  electrode 

hi^h-lreoi  eiicv     current     tor, 
5S4 

h  ifih-1  n  'qiiet  lev      current      to, 
(11.-) 

properties  and.  5(1(1 

r-my  for,  "),S5 

Gundelach's  \vatcr-cooled  x-ray 

vacuum  electrodes.  :>s|,  ,">!) 

7.\!\i-    elec:ro!\'tic    medication 

tube,  7ti:; 

connected      with     induc- 

in,  !l)7 

x-rav  tube.  heav\-  anode,  7(10 

tion-coil.  .")(')(  i 

(lonorrheal     arthritis     of     knee, 

'light   anode,  '7(12 

with     pole     of     Tesla 

iodin      anaphoresis      for, 

Gustatorv     nerve,     reaction    of. 

transformer,  5(15 

11)7 

17(1 

with     stati"     machine, 

radiography  in.   111^ 

Gutta-percha   as  insulator,   225 

5(15 

rheumati.-m,      caivanic      cur- 

(•k'ctrost;itic  capacity   of,   225 

and     I.eydeu    jar, 

rents  for,   !_'.") 

for  iiisiilat  iiiL',   5'.i 

5ti(i 

stat  ic  wave  to  prostate  for, 

insulation   for  j-rav  conduct- 

effects  through  clotliinsr, 

77 

inn  cord-,  7:57 

."7i  i 

(ior!  ultraviolet   lamp,   I'iffard's 

resistance  of,  221 

for  abscess,  WO 

nuxlification,  H7(l 

Guyon'.s     treatment     of     incon- 

tor acne,  (125 

Clout,  articular,  radiograph'.'  in, 

tinence  of  urine,    (2(1 

for  alopecia,  H25 

11  Hi 

Gvmnotus,  static  electrieitv  in. 

for  ai>pendi"itis,  (ill 

elect  ric-li<_'ht    baths    for,    40s. 

'.".1 

for  calculi,  5sr, 

(is•^ 

(Jynecoloiry,          high-frequeucy 

for  ccllulitis,  <12!i 

galvanic  currents  for,  42."i 

current    in,    5s] 

for  chilblains,  (i2(l 

hifrh-frequency     current     for. 

h\-ilro-<-lectric    sitz-baths    in, 

foi  chorea,  5  '.12 

,")7."),  i;u.") 

'  447 

for  colitis,  ti  in 

lithium   cataphoresis  for.    His 

for  constipation,  1110 

merciirx    vapor  liL'ht  tor,  tiv.l 

for  diabetes,  57'.',  5!l!> 

radiosrapliy  in,  1  !  Hi 

HAIIKI;      process     of     obtaining 

!i  r  1  )upuyt  n-n'.-  contrac- 

radium    i  rinkins;-\\  ater     for. 

nitrate-  from  atmospheric  air. 

tion,  5117 

l_'ii.") 

"jS 

l'o'-  eczen  a     il'M 

rheumatoid,    radiotrraiiliv    in. 

Habit  spasm,  electricity  for.  51!) 

fur  cpithelioma,  (12! 

1  1  Hi,   117! 

Ilaljitual       constipation,       elec- 

for furunculosis,  ti2i 

tissue  oscillator  for,  (id! 

tricity  in.    !:•;! 

for  trout  ,  (i(l."> 

(lout  \   deposit-,  thermopcnetra- 

Hair,   loss  of,   from  x-rav,   11:55, 

for  hay-fever,  HI1.) 

tion  for.  ill).") 

1  l:-is 

for  herpes  '/.(  istel  .  t>27 

to,,  hu-,   1117 

standini.'   on    end    from   static 

fdi     indurated   cicatrices, 

(  Irai  ..   17-i 

electricity,  21 

Ii27 

(  :•  .:::.-'  .  :•;:-.   ill  nl  .   L'lili 

1  lair.    !:•  \  i,  i-lectrolj  -i-  for,   1  IS 

for  larynsrit  i-.  oiv.i 

C  nun-ion,  -'liii 

x-ra\    for,    11s 

lor  lupus  er\  t  hematosu-, 

(  Inim-molecule,   L'liti 

Halation',  SOU 

i  i  2  v 

(Iran  -[Kirtice.  L'lif, 

experiment,  7'.'2 

tor      molliisciim      conta- 

•  '.'.  r.'ii 

Hallux    valjru.-,  radiotrraphy   of. 

tr  i  o  s  u  n  .  o  _'  s 

•     ,  !_'.'. 

KIMI    KIM 

I,    -:,,'..  -it;    .    ll(i:5 

l'"l.   P<<    -          -     h;  . 

llami    1-1    inn  rn:])ter,   141,   112 

for  painful  fiat-foot,  .">!»!  i 

127,   !Js 

\Va-n.T,    with   faradic   cur- 

tor peril  j-i  i'  i  -.  ii_".  i 

(  Iran  liar     iid-.     hi- 

rents,   !5s.  iiin 

for  phlebitis,  ii:5O 

iirri'in   !'•  ii  .  lils 

llampson   radiomet,  r,    115s 

••  ''-^ 

i  ;  i  x 

Han.l,      •:•'..;,,        .;,      injected, 

-•    •.   jnj 

:             -.11  25 

n  1     •     p!.-tria.  !77 

•  -      -  .    1  i  1!  >  1 

for  n  '  '  -i  '  di-i  a-i  -,  >'d  1 

lefon      •       if,  radi- 

1  1  1  '    1  '  '  i  '  •  '  -  '  '  '  i  -  <  •  •  '  -  1     tile 

-..-...  li.-,s 

..--tt,',  -.   in.  10H7  ' 

(ill-'1         TIM.        ;  i  i  i  -  1  !  ]  '  '  '  '        til         1  :  1  -  1 

i.  ins.-, 


,0s! 

.  '  •  '  '  ' 

....       . 

1    '     '  •  -  '  .:.!•        ••:  ':'          '      •-• 

<>  1  ^ 

•    ••       •   •  .  r:;n 

s|  ! 

I'M  I              •    '  -  .    '  •  _'    i 

•:.  •     .    HIl! 

pha'aiiL'es      of,      :-  .    -      • 

•    '.':•'    o-i     •        '         oil  1 

i  ,  •  -  -  •    •   •  .  ~:,(  i 

•!     ,       !..-          p                  .       1    '"- 

i  ,               •                  1  ,."  1 

7l'ii 

ndi  iirra)  i 

• 

. 

.       .             ij;,> 

1  1  02 

•  "'~- 

!,-•••.             .          •           ; 

:    ;;';-,^!,ll:i,,7. 

(i                                             •                    •    .      .- 
'       '         .         ,     Jlli 

• 
r.  MJ 

1302 


IXDKX 


Hand  resonator,  "..'>() 

Heart,   size    of,    estimation    of. 

Hemorrhoids,  diathermy  for,  630 

raphv'to  show,  ll'tt 

and,    1007 

rent  for,  012 

x-ray  dermatitis  of,    1  1  Ci 

position    of    patient     in, 

faradogalvanic     current     for, 

Hanfeid  tis.-ue  o.cillator.  0<i:5 

1008 

012 

Hard     palate,     epithelioma     of. 

fluoro.-copv      to      estimate, 

high-frequency     current     for, 

x-ray  in.   121.". 

1007 

612 

rubber  a.-  .-ub.-titute  for  class 

Lepper-Immelmann    met  h- 

desiccation  for,  012 

in  static  machine.   :i7 

od,  1007 

hvdro-electric    sitz-baths    for, 

in.-ulatmg      properties      ol, 

radiographic        estimation, 

447 

lo,s  of,   22". 

1007 

internal,   high-frequency   cur- 

x-ray tub.  -,  7(^.  sivl 

Tousey's    method    of    esti- 

rent  for,  012 

and   Noire',  radiometer.   1  l.'.x 

stimulation  of,  :5.">0 

current  for,  012 

H:ii'i>oon    and    cannula    method 

modified  by  poisons,  3.")2 

sinu.-oidal  current  for.  012 

o*    localization.    Mi'.i 

pneumoga.-tnc  and,  :5"<2 

ultraviolet   ray  for,  001 

Hart',  electrode  tor  lulguration. 

teleradiography  of,  KMI7 

with  venous  congestion,  high- 

method       of       liigh-tr.-quency 

of,   1007 

Henry,  141 

.-park,  lor  cancer,  .".111 

Heat     and     light,     radiant,     for 

Hepatic     abscess,     radiography 

Ha\  -lever,    high-frei  (iieney    cur- 

war  wound,,  (iMi 

of.  1021 

Hea.i    bri  e'zi  .     12.    I')7-6'J 

blue-light      treatment      with, 

calculi,     high-frorjuency    cur- 
rent for,  ."iMi 

po-rioii    i,f,     in     paralysis    of 

from  electric  current,  210,  202 

x-ray  for,  .r>,s'7 

-pmal  acce,,ory,    17". 

from  ,-tatic  discharge,  oS 

Hering'.-  double  myograph,  .'52,>> 

radiography  of,   M  t,   002 

from  x-ray,  71:5 

Hermann'.-    theory    of    electro- 

exposure  for,  ML' 

latent.  L'Oo 

ton  u.-,  L'Mi 

sen.-ory  -\  -teni-,    Hi.">,    liiii 

mea.-urement  of.   173 

Hernia  cerebri,  fracture  of  skull 

Headache  in  ri'Tvou-  dy-pep,ia. 

mu,ciilar      contraction      and, 

and  fluoroscopv  to  differ- 

galvanic current   for,   ".20 

:;ii 

entiate,  00-1 

,ick.  c:ltaphore,i,  for,    100 

nervous  excitability  and,  :{-l.'5 

hematoma    of    seal])    and, 

p,  .    ;•  it\    and.  40 

of  ionization,  20o 

Huoroseopy    to    differen- 

static    iu.-ulation     and     head 

production  b\'  electricity,  202 

tiate.  001  ' 

breeze   for.    71 

by     electric-light      current. 

radiographv  in,  004 

Hearing,  effect  of  electricity  on. 

regulation,  Mi,  s7 

Heri.es,  facial  palsy  and,  474 

'••>'•  >'2,  M'l.'i 

b\-  voltaic  pells,  07 

neuralgia,  clectrieitv  in,   .".00, 

lo.-.-    of,     in    facial     paralv.-i,, 

regulation,  Mi,  S7 

501 

171 

in    bod\  ,    .-tatic    el(*-tricit\- 

zo,ter,    galvanic    current    for, 

sen.-i  s  of,   I','1 

and.  71 

427 

telephone    as    te-t,     170 

in  conducting  wires.  221 

high-frequency  current  for, 

Heart     di.-ea-e,     high-frequenc\ 

ra\>,   therapeutic  uses      i."..") 

022,  027 

current   for,  .".M 

of  gri'at  wave-lengtli    i,o!a- 

radium  in,  dosage,  120.". 

hydro-electric       bath,       in, 

tion  of,  00.") 

static  re-onator  etlluve  for, 

-inusoidal,    H'i.    117 

,  tatic  electricity  from,   ."."> 

7:5 

rapid      -inu-oidal      current 

unit  of.   17:5 

ultraviolet  ray  for,  001 

for,  1  in.  1  !  1 

I  leater  coil  of  platimun,  201 

H.-rtxian  waves,  ."".1.  ".00 

.-inu-oidal   current    in.    1  12 

Heating    effe,-t.-    of    static    di  — 

Hertz',    experiment    with    cath- 

static elect  ri'-it  \   in,  7  1 

charge.   .".', 

ode  rays,  712 

till  •  '  -  •  :    dtern  it  inn  currents 

ol    1  L--UC,  b-.    electric  current-. 

Heterodyne,  Cabot.  7.".0 

on,  :',72 

20  ii 

High  x-ray  tube-,  70:5 

of   break-r-hock    on,   :',7  1 

Heberden's  nod.-,  1117 

re-ult,  from,  xlO 

•     ..:.•:      k  on,  :-:7l 

Hefner,  li.'.7 

High-frequency   apparatu,.   .">:{!) 

o:  c,,n,|en,er  di.-charge-  on, 

HI   ineeke'-      experiment,     011     et- 

conden-er,  for,  :;7."..   107 

;-;71 

fect  ot  x-ray  on  marrow,   1  1  12 

I.evden  jar,  as,  L'i'.O 

rj|       ••:•.:...,,•.-     i-i«rn  r.'     on, 

l|e:i.z-Haui  r     <|iialilncter,     s.  I. 

lioehetort',  monolith,  2oO 

,7.  , 

X  \~t 

d  A'-onval.  oil.  .".10 

of  high-tension  current  -  on, 

Heliotherapy      in      chronic'      in- 

effect- of  working  near,  :i()7 

20". 

fect  ion-  o,teomye!iti>,  001 

Cerman,  .V.2 

of  1    A  -ten-    ,1         •   ,  •  •  -  on, 

H.  Ii  in    from   radium,   1  2..2 

gla-  in,  220 

20.' 

ga-  in  j--ra\    tube-.  ,  .;.", 

l.e-,ien    jar,    as     part     of. 

ot  ri  aki    -hock  on.  :;7i 

producfioii  of,    12.'.2 

107 

•      (.en  ing  -1       .       •:.  ,;7  i 

quantity    of,    12..2 

i  ludin,  .",11.  .".is 

ot   '-Mi'.'ulvi'on   ~'l     cervical 

Helndioltx  laradic  coil,  l.'.s,  l.'.O 

Tesla'.-,   ,')(],   ."..".1 

•-,-•.•        ,1       ;  i  •> 

rent   lor  -t  imu'.at  ion,  .',.','> 

coil,  :.;.". 

...       .'    _,7s 

II,  rnaton  a   o!    -i  alp,  fracture  ol 

•  :  ,    work,  Ti     l:t,  712 

•    i      it        ol,     in     lock  jaw, 

-kull  and,  fluoro.-copv    to 

current,     r.itx.      See     al,o     Ui- 

.  IT.  r.  ntiate,  O>  1  1 
;,.,,.      een  |,ri      and       fluo- 

,;//,.  rn,  i. 
flei       irethal      ,','•'  rol\  -i-, 

r-o-cop\     to   din.  i,  ntiate. 

•  .  ''07 

'.ill  1 

alter  rial  ing  dii  rent  tor,  .".  1:5 

-.        :/.  .     |IK)7 

....         .     ,in) 

amperage     of,      m>  a-uring. 

ri,  .",.;.', 

Her                              •  •  .    17." 

7:,s 

11                  ...            tubel 

II,  miplegi  ,.    170,    177 

ane-thetic    effect     of,     after 

•  .  >..> 

urethral  ele.  lrol\  -i-,  ,".Mi 

'                        ...-•..•      lor.   :,lii,  r.17 

application,  .V.2 

1  1.  tin  ,gl  'bit.,  .  tie.  t   <  ,!   x-ra\    on, 

[  J,  .more,         •     ci        •  ' 

au't'ocon'du',  ti,m      cage      1   ,r, 

ortl      .       ••                ',  O'i,  .  '('.is             Hcmorrhagi     ti   in     hiL'h-ten-ion 

.",17,  .",."..'. 

,    irrellt-,    L"i."i,    2'»i 

bacterial          effect-,          .",1,0, 

bipolar    rr-,onator   lor,   .".."il, 

...                 .          ,                .       .                               ;   ,    ,                i  ;      ,  ,  .      i   .     ;  ,     T  i  ,,    • 

....         [  i          in  .  1  o»  i.i 

:••    .       •                ..--,.,  ]_• 

'  effect-   ot,    r,17 

IN'DKX 


1303 


High-frequcnoy  'current  by  auto- 

High-frequency  current  for  epi- 

Iligh-frerjuenc\-  current  for  pul- 

conduction,  553 

lepsv,  501 

monary  tuberculoMis,  H07, 

capillarv     vasoconstrietion 

for  epithelioma,  (121,   1210 

11.  SO 

from,'  579 

for  erythematodes,  (12! 

for  pvorrhea  alveolaris,  H|5 

rataphoresis  with,  4  1  1 

for     exophthalmic      goiter, 

for   Ravnaud's  disease,  583 

condenser     electrodes     for, 

520,  1  IDS,  ]  100 

for  rectal  diseases,  (111 

563 

for  eye  disease,  (Us 

technic,  til  1 

large  size    5(15 

for  facial  neuralgia,  503 

fistula,  (113 

crown  cfiiuvcr  tor,  5(13,  .If  14 

for  fibrous  conditions,  597 

prolapse,   (112 

d'Arsonval,         application, 

for  fissure  of  anus,  (112 

stricture,  013 

351 

for  fistula  of  rectum,  1113 

ulcer,  (113 

ozone    inhalations    with, 

for  fiat-foot,  painful,  50(1 

for  renal  calculi,  580 

Go 

for  furunculosis,  (121,  (127 

for    rheumatism,    575,    509, 

small  solenoid  for,  552 

for  gastric  atom  ,  (KM) 

1100 

transformer  for,  511 

diseases,  009' 

Tousey's  technic,  OCX) 

definition,  .'50 

for  gcnito-urinarv  diseases, 

urine  in,  (100 

desiccation      by      high-fre- 

583 

for  Kigg's  disease,  (115 

quency  sparks,  5(10 

for  gonorrhea.,  58),  585 

for  sciatic  neuritis,  505 

for  hemorrhoids,  (112 

for  gout,  575,  (105 

for  sciatica,   507,  508,  503, 

for  hvpertrophied  tonsils, 

for  granular  lids,  CIS 

504 

fi  1(1 

for  hav-fever,  tl]l» 

for  seborrhea,  H28 

discharge  of,  simple,  53s 

if       t  ,     -j(\(: 

for  heart  disease,  581 

for  sinusitis,  (11!) 

cilects,  ouo 
dee]),  5(10 

for  hemorrhoids,  (112 
for  hepatic  calculi,  58(1 

for  ^kin-grafting,  (12!) 

eliminative,  .170 

tor  herpes  zoster,  (121,  (127 

for  spasmodic  stricture,  584 

general   application,    571 

for  hypertension,  57(1,  577 

for  sphincter  ani  paralvsis, 

local,  frtlX,  570,  571,  57:{ 

for  impetigo,  (121,  (127 

613 

on  animals,  573 

for  impotence,  5S7,  (113 

for  sterility,  433,  5S2 

on  bladder,  570 

in  neurasthenia,  525 

for  stricture  of  rectum,  (113 

on  blood,  571,  575 

for  infantile  paralysis,  570, 

for  sycosis,  til'l 

on  hypertension,  57(1,  577 

500  • 

for     svnovitis,     rheumatic. 

on  man,  573 

for  insomnia,  .">!>(• 

500' 

on    mucous    membranes, 

for  intestinal  diseases,  (i'vt 

for    telangiectasis    of    nose, 

5(1!) 

for  joint    injuries   and   dis- 

(121 

on  skin,  5(18,  574 

eases.  583 

for  tinnitus  aurium,  CIO 

on  urine.  575 

for  k-loid,  (127 

for  trachoma,  (118 

pathologic,  3H7 

for  keratosis,  (124 

for  trifacial  neuralgia,  503 

physiologic,  .'5(17,  50s 

for  kidney  disease,  575 

for  trophic  diseases,  583 

systematic,  573 

for  larvngeal  cancer,  (100 

for   tuberculosis,   570,   580, 

thermal,  575 

tuberculosis.  H07,  t'l'ls 

(107 

eflluver  for,  crown,  5(18,  5(14 

for  larvngitis,  00!) 

genito-urinarv,  584 

electrodes  for,  380,  408,  545, 

for  leukorrhea,  581 

of  bladder,  584 

55!  I 

for  locomotor  ataxia,   515, 

of  kidnev,  584,  1180 

eliminative  cfTeets,  570 

502,  1102 

of  larynx,  (107,  G08 

Fleming   rectifier   for,   53'J 

for  lumbago,  5!!3,  501 

of  rectum,  5s  1, 

for  ubseess,  (130 

for  lung  diseases,  (107 

pulmonary,  (107,  1  IS!) 

for  acne,  1121,  tli>5,  1171' 

for     lupus     erythernatosus, 

for  ulcer,  (120 

for  alopecia,  1121,  t'i_'5 

H2s 

of  rectum,  (113 

for  anal  fissure,  (112 

vulgaris,  (121 

for     uterine     malpositions, 

for  angina  pcctoris,  581 

for    mediastinal    Ivmphatie 

5s  2 

for  appendicitis,  lil  1 

tuberculosis.     ll'SS 

for  varicose  veins,  57n,  tii'O 

for      arteriosclerosis,      575, 

for  met  rorrhagia,  5.S2 

for  vcsioulitis,  5s(_i 

600 

for  moles,  (121 

for  warts,  til'l 

for  asthma,  5,  5,  Ii07 

for     molluscum      contagio- 

for    weakness    of   sphincter 

for  atony  of  stomach,  fiOH 

snni.  (12s 

ani,  c.12 

for  atrophv  <jf  optic  nerve, 

for  mouth  diseases,  1115 

for      xanthoma      multiplex, 

Mils 

for  multiple  sclerosis,  5]  1 

(12!) 

for  brorichit  is.  (107 

for  nasal  diseases,  (11!) 

frequency  of  oscillations  in, 

for  calculi,  5sH 

for  nervous  diseases,  5s7 

511 

for   cancer,    genit.o-urinar\  , 

t'or  neuralgia,  570,  503,  5!M 

from       induction-coil,    541, 

5M 

for  neurasthenia,  52'i,  575 

512,  513 

of  breast.   1221 

u  11  h  h\  pel-tension.  5s7 

from   PitTard's     hyper-tatic 

of  lar\-nx,  HO',) 

for  ncurit  i-,  5!'.'! 

transformer.   517 

of  rectum.  5s  1 

for  obe-it.x  .   575.   (103 

from    static    machine,    511, 

tor  cellulitis,  H2o,  r,:;i) 

for  optic  atrophy,  'Us1 

517 

for  cervical  erosions,  5s! 

for  on-hit  is,  •">*:< 

d'ArsonvalV,  05 

for  eervicobrachial   neural- 

for ozctia.  'il'.i 

(laitTe's      transformer      for, 

gia.  50i  i 

for  pain.  5'.i(,  505,  50il 

513,  713 

for  chilblain,  ti.'il 

for  paralx  sis,  5O(  I 

general  applicatiuns.effects, 

for  chorv:,,  50l> 

agitaris,  501 

571 

tor     cicatricul     conditions, 

infantile,  501 

(lui  leminot's,    for    arterial 

5'  '7 

of  -nhincter  ani,  (113 

h\  perten-ion.  553 

for  colitis,  till) 

for  I'a'rkinsi  n's  disi  a  •••.  501 

ted,  m..  553 

fur  cniistipal  ic  m,  57<i,  tllu 

for  pelvic  exudates,  5s_> 

hand  resonator  for,  55'i 

tor   const  itutinnal   disease-, 

for  pert'i  .rat  ing  ulcer  i  >i  foot  , 

high-tension.  551 

507 

(120 

effects.  574 

f,  ,r  c;  -1  :i  is,  5.X<) 

for  periostiti-,  1120 

local,  5118 

for    defective     metabolism, 

for  phlebitis,  5,  (>,  (130 

in  gynccology,  5M 

5  7  5 

I'*  if  pli-urit  ic  pain-,   5'.Kl 

indurated-iiber    couch     for, 

fur  dial).  1  >•-.  ."'7'',  507 

fur     i'!   ign  ssive      rnusi    . 

515 

:  11    I  Jupuvtreri's      coin  rac- 

atrophy.  51  t 

large  si  ilenoii  1   :  ,r.   553 

tion,  5'.)7 

for      prolap-e      of      rci-turn, 

lighting  ineandcsei  ut      .•    • 

for    d\  -pi'p.-ia     of     neiira.— 

('.!_' 

bv,  511 

thei    :.  527 

.t  ititi-,  5.M1 

l,,,,il  effects,   5lis,   r,f,0,   573 

for  ear  disea-es,  til'.l 

tor  pruritus,  i',2s 

locally,  55H 

for  I'c/ema,  I'rjil 

ani  with  cr/cma,  (113 

measurer:,,  nt     in     aut'  n-on- 

with  priiritu-  ani,  013 

for  p~,  iriasis.  (ijs 

n,  517 

for  epidid\  rnitis,  5SJ 

t'  ir  piilnn  inary  diseases,  'ii  >7 

of  os                     '  .   "•  i  , 

1:504 


INDKX 


liph-freimency    current,    mf-tal 

IIiph-ten--ion     currents,     thera- 

Hydro-electric baths  for  progres- 

c-..nili II-.T  electrode-  for, 

peutic    applications,    harm- 

sive    muscular     atrophv. 

.    ,  .    ,d  I,    ., 

1.  --n,--  of,  21  »; 

:>]  \ 

»l  of  appl;.  iiiL-.  .-.",7 

hiph-freiiuency   current,   VV  1 

for  >kin  disrascs,  42G 

mon.  .lnh  condenser  for,  VV2 

effects,  V7  1 

four-cell,   liili 

rnu-     .:  ;i    '  •  ,nl  racl  i,  ,n.s    by. 

local,  VliS 

nalvanic,    1  i:i 

.".  7  ii 

for  neiira-t  h"iiia,  V20,  V27 

for  litihtiiinp  pains  of  lo- 

<  >udin.  ."..M 

t  ran.-former,  7  1-i 

coinotor  ataxia,  4  4:j 

re.-    nator  for,  ."4s,  VV:-> 

Hip-joint,    di.-location    of,    con- 

in sciatica,  44){ 

•   ,i   :  .r.  WO 

genital,      radionraphy      in, 

phvsiolopic  effects,  442 

o-cillatory  character  of,  V:-;s 

1071 

i)olarit\    and.  4  l.i 

os,  ill.,  -cop,-     f,,r    studying. 

radiography  of,    l()(is 

induced,  442 

7:;s 

tuberculosis  ot,  displacement.-; 

larne  silicic,  4^7 

••    m,  VO'.i 

in,  1070 

shovel  flc-ctrrxle  for,  4:js 

patln  doiric  effects,  oO'.i 

MeCurdv'.-      transpelvie 

.-inu.-oidal,  44.") 

penetration-  of,  ."7« 

line  in,   1070 

blood-pres.-ure     in,     4iV, 

per;-4  dti     eft,  cts.  .",7  1 

radioL'raphv  ot,  loii'i 

!  Hi 

plr,  -i  ,|i  mi     •  ••',     •  -.  ,'jlis,  VOx 

roiiiprc'r-BUjn      band     for, 

effects  of,  440 

rectiiii-r  tor,    Kleinm",   Vi'.i 

101  is 

in      cardiovascular      dis- 

re-.iiiators    :or,     .Ms,     .V.."., 

plate-tunnel  for,  10(is 

ease,  44V,  440 

,Vji; 

reduced  radiability  in,  U»','.i 

in     In-art     disease,     410. 

rheo-tat  for,  7.;o 

-ipn.-,   lOii'.l 

417 

Koch.  .Jon      resonator     for, 

]\irr/.  compa.-s,  x(i!t 

pruritus  from,    1  10 

.,...,,  .  .  o 

Hodckin'.-     di.-ea-e,     /-niv     in, 

uses  of,   110 

it  ion  conden-er  elec- 

1 ins 

switch-board  lor,  livS 

trode  for,  V01 

HotTa'.-      tcchnii1     for     injer-tiim 

triphase,  417 

solenoid  tor,  small,  W2 

ox\-(ren  into  joints,   1074 

effect-,    417,    44S 

i-park   di>i  liarpi-s   from,    ef- 

Holder-, exposure,  for  films,  sin 

tub  tor,  4:i< 

fect-,  vo'.' 

Hollow    \\ooden    electnxle,    u.-e 

with    negative   electrode   at 

-ystematic  ,  fleet-,  :,7:-', 

of,  t'.S 

dorsum,  4  Cj 

Ti  .-la,  WU 

11  An.  ,-tat.ic  machine,  :',  l-ii7 

with    positive   electrode   at 

Texeira     tran.-former     for, 

-tartitifr  of,  :;i.   11 

•     niicha,   1  i:', 

.).").") 

Toepler    machine    to    ex- 

sitz-bath.-, 447 

thej-mal  effect,  V7V 

cite,  :j,2,  :-;:•! 

Hydrogen    electrode    for    mpas- 

T  '    '      trOll  til!      -Ill     .  -  ,      01-',      '  »-'  1 

-    u.  n  .-.  01." 

1  1  '  >'./.  K  IK  •'  'I  i*  -        '  '!  i  roniorjicixoi)  i- 
eter,   1  lV:i.   11V1 

e  eetrode,    17s 

Iran  -lor  sner  for,d'Arson\~al, 

unit-  at   nkin  di.-tanee,    11VV 

r-ntrance  trf,   into  ar-ray   tube. 

V  1  1 

treatment     of     fa\ii.-, 

701  1 

C,  dffe's,  vi.;.  71:; 

1174 

liberation  of,  in  voltaic  cell,  s:> 

Te.-la,  VV1 

HoorweuV  formula  for  ,-tLmula- 

to    reduce    vacuum    in    x-rav 

T.  -...  ira,  VVV 

tioll,    oSS 

tube,  700 

unda::  p.-d      '  ,-ci]lati,  IHS      in. 

11  ,r-.-power,  171 

x-ra\-  tube,  ,  07 

c,:-;.' 

Hot    air   for   moi.-ture   in   ,-tatic 

]I\  dronei.hro.-i.-,  radiography  of, 

vaci.um  electrodes  for,  ."IV, 

machine,  40 

1002 

.V.'.i.      See    al.-o     i 

Hot-wire  galvanometer,  1  ,4 

Hydrophobia,  radium  in.   12(11 

.   .    - 

(  :•..,:;.  '-.  si;ii 

H\  peiaciditv,    radiocraphv     in, 

vr.lt  ac"    of,  measurinir,   7:;s 
r  r.  ,    ,     i  1  t  ,  .  r    -  r  ' 

rnilJampercmcter,  ]~>\ 

'102!' 
1  1\  t  M  Te\  ci  t  at  ill  it  \~    .^''1     401 

..   -       ,          '    '  '  1  .     C  '  I  ,     .  M  •  , 

if,  .".:•;'» 

alt,  inatintr    current,    21  1 

ilyperidrosis,    x-rav    treatment 

.••:.••    '    '  .   HI  ••..•/.  VV'i 

IIour-irla>.-      -toma-h.      radion- 

'for,   1  177 

linn  of  term,   l''s 

raphy  in,   Hi:iO,   KCil 

1I\  ])(  rstatic  cutr«  nt,  ."4  ,  ,  Vis 

-et  ,  .".  t  1 

Hnl!'-  apparatiL-  for  x-ray  work, 

'transformer,  Piffard,  Vis 

-;   irk-  i    -  can   •  r,  ."'.1 

7V  s 

II.;,  rti  i.  -ion.       arti  :  ial,       dia- 

dc-icr-ii  ion     •  :     -kin     from, 

Hul-t'-  teehni'1  tor  fra-tric  radi- 

thc  rmy  in,  (ioO 

ipraphy,   1(«1 

CniUeniinot'-    autoconduc- 

,.-•;•     ,  -:     •    -.  .VKI 

II  in     n    li-.-ue-,    ab.-orption    ot 

t  ion  for,  Wi 

•  .•  .    •          d".i- 

-  1  •    .  ,  .,7 

inducto-resonator       eflluvc 

-    .".  si  ; 

Humei           fillo:         .  i[)V  of,    lOsi; 

for,  7(1 

for    pa;! 

:  •      tuti      of,     fluoro-'-opy     in, 

aiitoeonden.-ation      pads      tor, 

.-,  VOO 

-       i       ner,    ID'.I'.I 

aiitoconduction  cafe  in,  V7o. 

•  .!..         •           •          -,Vii 

radioci     :          of,    1  0'.i'.l 

V77 

-   •    :        '-,  7.;.; 

.-•         tel        '     ,,..,-.,  -It  \        01 

!    rh-  frei  |iienc\       cuncnt       in, 

-.-     7-  ... 

•     •       t,  1         f.  Id!  IS 

.'.  7'  ,.  V77 

-    •    • 

-.••••'.•      iry    ol, 

i.  nttri  nization    of    snptarc  nal 

•      .    •      7  .  ;  .- 

'raph.\  .    10:0 

,  ap-ule  for,    1  KH 

. 

T                                                 •      •                         •.'-,' 

Ial   current.-   for,    1  1  1 

• 

•       • 

•     •  •   . 

KISS 

•  •  '.    ,  •  1  1  M  ,  :  1  1   I  o  i  ,  V  s  , 

'  •     '         '  7. 

1     -  •       •  ,    •  •      t;;r<     .,!,    radi  •:'- 

11;,  p,    -h\  loidi-m,  iodin  !•;.  '    .7 

KI'I'.I 

II;  pell          1              ,      cll-etl 

.  -       ,  -        ,  - 

M.        .              .           .          ,      I  1  -.  ", 

-  .  ^.  \ 

t!     'ity     lor, 

e!     i;,,l;  -i-  tor,  ".no,  :>:;,  1  1;;. 

;  i  ;  ,  1  1  v 

. 

•      in    -in,    12,ii 
•a      in.   11 7:1 

:  .    117 
:    liver,   -talic  -A 


IXDKX 


Hypertrophy  of  tonsils,  high-fre- 

Incandeei-ent      lamps,     reflector 

Induction-coil,   manipulation  of 

l|llelie\    doiccation    ill,   li  Id 

tor,  non-loi-iir-intr,  tiii.'j 

Coolidge  tube  witli,  7s.", 

uf    ;  n  i  buiated    In  me--,    ioni/a- 

resistance  of,  (;.")S 

operated  bv  <-l<-etri'-  light  'ajr- 

tinii  i  ir,   Hi7 

rub\,  s71 

I.I',    7  1  !  1 

!!\  pnotie  effects  of  .-tatic  elec- 

tot's  of,  I')."i7 

1)V  galvani'-  cell-,  717 

t;ii-it\  ,  72 

tl;era[ieiitie,   (M.S-lil'il 

power  of,  Io2 

Hypo,  artior,  of,  S71,  s7.">,  ('77 

voltage  of,  li.").S 

soft-iron  con-  of,   1  17 

lor  plalo.  ssl 

with   reflector.  C.."S 

Spot  ti.-  wood's,   lot 

for  print.-,  ^M 

li^l.T  bath.  ].h\>io!oL'icefTects, 

12-ineli  rheostat   lor,  7.',0 

foniii;!.-!  lor,  N77 

ti.S'j 

voltage  of,  i.v; 

Hvpo-aeidit  v,     radiographv     in, 

temperature,  lis.'i 

watts  of,  i.-)2 

'10-'!  1 

therapeutic  effect  >  of,   (iMl 

without     iron     core,    -eparate 

Hypochlorhydria,     static     elec- 

Inci])ient   cancer    of    brea.-t,    bi- 

electromagnet for,  Io7 

tricity  in.  7"> 

polar  ioni/ation  for,   101 

Inductive     capacities,     ,-pceial, 

Hypo-excitability    and    shi<_r<_'ir-h 

[ncisors,  lower,  radiojrrapiu-  of, 

21  o 

contractions,  :-!!il 

s»:j4 

re-i.-tance,  .">  1  ,   ",!( 

faradie,     uith     galvanic     for- 

uppc-r,   r:idioyraph\-  of,   (l.'il 

of  voltaic  cell,  !K) 

mula.  ii'.M 

Incontinence      of      urine,      elec- 

Inducto-re-onator   aetuated    by 

galvanic,     with     normal     for- 

tricity for,  7:i,  42M 

static  machine,   ,  o 

mula,   faradic   hypo-excita- 

Index-finiier,     reduplication    of, 

effluve,  bipolar  static,  for  low 

bility  with,  :<!»!  ' 

10d7 

blood-procure,   7'i 

H  Vpoilio.-r-al    IKTVC,    pafalv-i-   "I, 

47.", 

Indirect  >park-,  'ili 
and  breeze,  tis 

tor  paralyzed  and  atro- 
phied   n.u-cle-   from 

Hypothyroidism,  iodin  in,  Oo7 

electrode,   117 

war  injuries,  7(> 

1  ly.-teria.  I'lcrt  ricit  y  in,   ">21 

spray  electrode,   Tousey's,  0!) 

for    arterial     hypertension, 

in  paralvsi.-  after  injury,  ma- 

.-tatic  bree/e,   (Hi,   (17 

7ti 

lingering  in,  -iCO 

for  neurasthenia,  ."i2t 

for  asthma,  70 

for  brorchiti-    70 

primitive  character  o!,  ->21 
p.-vchoneiirosis     anil,      differ- 

Induced currents,  l-^.'i 
cause,  1M:< 

for  diabetic  gangrene,  7(i 

entiation,  .">21 

faradic,  1>  1  7 

for  ton.-illiti.-.  70 

syinptiinis  of,  treatment,  ,~)21 

for  ,-horea,  r>10 

ftr<},,.ir\,.    li.i  t  ti         ll'> 

Indurated     cicatrice-,     hii_'h-fn- 

Hysteric  amain'osis,   lv> 
aphonia,  17.">,  is:-! 

ior  electric  Darn,   \\  — 
for  exophthalmic  goiter,  .">20 

j-ra\'   for,   ti27 

bnlhar  palsy,  470 

for  neurasthenia,  ~>'2  \ 

Indtirated-fiber  couch,  old 

contracture's,   ISi 

for  poliomyelitis,  .">14 

Induration   in   traumatic  arthri- 

paralysis,  l>o 

for  s'-iatica.  .">()!  i 

tis,  static    wave   current    and 

vomiting,   IV! 

for  stimulation,  .S.'is,   l!)o 

sparks  for,  71 

in  parallel  wire-,   l.'« 

Indii-tria!  currents,  death  from. 

in  ,r-ray  primary  coil,  S.'iS 

o:;o.  ooo,  o.'-;o 

isolated    shock.-,    curve    of, 

Inert  ia,-  maL'netic,   1  1  t 

li  HTHYOMS,      static      electricitv 

ISS 

of  water   flowing   through   in- 

tor.    127 

for  facial  paral\'sis,  4  i  2 

clinetl  tube.  247 

Ileum,  radiography  of,  1020 

for      incontinence      of 

Infant      stomach,      radiographv 

Ilium,    anterior    superior    spine, 

urine,  42!) 

of,   I02!i 

mii-eiilar     fracture     of,     radi- 

stimulation bv,  ">()!) 

Infantile  bulbar  pal.-\-,   !7ii 

ography.    1H71 

laws  of,  i:« 

c.rcbral  pa'.-v.  elect  ricity  !'  >r, 

[linn  matioii,  vacuum  tubes  for, 

static,  »',.",.     See  also  St  "   • 

517 

o.">2 

;,.,/„,;,/  current. 

paral;.  -..-.  high-frequency  cur- 

Image .-how  ing  on  ba.  k  of  film, 

study  of,  T.-JS 

rent  for,  o70,  .">!'(i 

040 

to  heart,  :{ol 

static  wav»  current  for,  .'>13 

Immobilization,      methods      of, 

undiilatorv  nature  of,  loo 

spinal      ]iara!\>is,      elei  tricity 

10!  11' 

Inductanc,.  rcjrulator,  oil 

fi  if,     ol   1 

•  •  .  r-ray  and,  !2o*- 

unit  of,  1  11 

Infected         plinct  t;r>'il         \\-i  ii;nd- 

Impetigo,     hiLrIi-frci|iie;:i-y     cur- 

Induction,  charge  by,  21 

wit!      fistulas,     copper     rata- 

rent   for,  021  .  027 

electromagnetic,      in     powor- 

-  -i-  for,   tut1, 

radium  ra\  -  in.   127c 

housc.  2Ui 

Infection,  dental,  symptom.-  and 

-tat  i'1  elect  ricit  \    1<  if,   127 

in  ttrounded  body,  2M 

lesion-      due     to     long 

Impolarixahlc  electrodes,  .'74 

1  1  *    \  ''-'  |T  1  V  '  '  '     ^         '  '7    ' 

in  itiMilate.l  bodies,  22 

standing.  "2'' 
n-i  danger  -:  ••    •'-    'i;;i  i 

1  >  ,    l;   is-He;  nioi  .1,  L'7! 

elect  ric  eiirn-nt-,    1:12 

his.'li-fre(iuene\    ("irrent   for. 

In.luctic.n-coil,   i:;:; 

iti  .."  ;•!.-.    •  reatment,  •"'.' 

osti,  i;iu 

and  stora  ire-battery  for  .r-ray 

I  nfectious     di.-ea.-i  -,     .r-rav     in. 

in     ncurar-th'-iiia,     L'alvanie 

work,  71S 

I2.SS 

curn  i.i   ;  ii  .  ."ijli 

•    i        ir,  2:;o.  LM2 

Inf.-rior     dental     canal,     radiosr- 

•  urn  nt 

•     n.   Its 

1>  if,   •"  L'I'I 

•       i 

maxil     .       •           >ic      if,     •  .  ;:- 

l,'i  \  naiilt  's,  L'7  ! 

212 

'  ,  "i  7 

1  Iicaip  le-rence,   t'i,"i."> 

win  n  n  ijuired,  2!o 

it  i.  'ii  of,  radii  igraphy 

inten-it;    ot,  li.Vi 

•  '    •  -         ••  .   1  .Vi 

law  oi.  i  ;:,.-, 

i.  212 

pi 

r.  i    :  •  •    tun    nf.  d.Vi 

•.••  i        .':.'.  _'  :.: 

[its 

[,,,  ..,,„!                    |                        . 

• 

•      r,l,y    of,     !IJx,     -.,-, 

i'.'i_>,  iv;i 

'.II- 

tierv  .  den-td;  rad      :rap] 

.       •      i      •           •  i  .  7  1  _' 

;    •                             .711 

•".I 

.  (  '•  '  x 

.   ,  i 

,'•'    '"    '  :  ''•'-."''   '.'  ''  :-'- 

r  i.'i  s 

....                                               .                      . 

•      .    '•   •' 

. 

•                                                                                                       ' 

-      .     -                                                                                                                                                -       ,      ,                      .                                                                                                                                                                                                                                                                    -     - 

'     •     ,                                                                                                                                              ....                                                                                                                                                                                                                                             -   _        1    ,,    ,.    , 

.  .'    •'    ','-"•  !  '    -  - 

'•••-.!• 

131  Hi 


INDEX 


Inhalations,    ozone,    with   static 
wave     currents     for     chronic 
bronchial  troubles,  77 
Inhibitory     nerves,    absence    of, 

in  voluntary  muscles.  .'Mil 
Injury  tiom  .r-ray,   1 1  Hi 

to      brachial      plexus,      static 

wave  current   for,  47H 
war,  physiotherapy  and  elec- 

trodiagno-is  in,  -151 
Inner   canthus,    epithelioma    of, 

.r-ray  in.   1212.   121d 
Innominate     artery,     aneury.-m 

of,   radiography  of,    lOOti 
Insaniu  ,  elictricity  for,  522 
In.-ide  wiring.   2OS 
In.-omma,    high-frequency    cur- 
rent   for,    5! Ml 

neura-tlienic,     static     in-ula- 
tion    and    head    breeze    for, 
523 
Matic  electricity  in.  72 

insulation  with  head  breeze 

for,  72 
Instantaneous     radiography     of 

In.-ulatcd   bodie-,  charge  by   in- 
duction in,  23 

physical     effects     of    Mafic 

electricitv  upon,  55 
ele.-trode  handle,  3S1,  5511 
high-l'reijueney  tube-,  551 
metal  hall  inside  hollow  metal 

sphere,  213,  214 
platform,  -11 
In.-ulation,  air,  223 

cement,  acid-proof,  213 

materials,  5!»,  212 

of  heavy  currents,  215 

of  human  body,  211     - 

ot  .-ilk,  212 

of  wire-,  223 

material-  for,  511 
of  wood,  212,  213 
of  j--ra\   conducting  cord-,  73d 
paper/212 

requirements,  20  s,  201 » 
re-i-tance      of      any       circuit, 
measuring,  212 

testing  of,  20H 
-tatic,  d() 

effects,  305 

in  obesity,  73 
tripe.  212 

In-u!ator-,  25.  "id'.l,  _':« 
If  la.--,  re-istancc  of,  22! 
/  ,•  •  :  pereha,  re-i-tanee  of, 

22  I 
pi  reel  lin,    :e-i-t;,n--e  of,   221 

Inten-ifii  r-,     -elenium     cell,     to 


Interrupter,  aperiodic,  142,  72S 
atonic,  1  12,  72S 
Heaker.  720,  723 
('aid well.  720,  722 
interruptions  of,  S52 
with  aluminum  cell,  S54 
Carpentler's,  72S 
commutator  t\  pe,  727 
condensers  for,  S.">7 
(  'ontremoulin,  727 

I.educ  modification,  144 
Draulfs  wheel,  s:,.-, 
electrolytic,    1  1') 

for  r-ray  work,  720 

mercury,  care  of,  727 
dip,  722 
jet,  721 
turbine,  725 
principle  of,  720 
rectifiers  for,  72:! 
Hopiquet's,  72,") 
\V clinch,  722,  723 
electromagnetic  current,  Sf>7 
for  triphasc  current,  ,s.">7 
vibratinfi,  111 
wheel  type,   113 
fc;r  alternating  current,  elec- 
tromagnetic, S.")7 
Villard,  Soli 
for  faradic  coil,  1.">S 
for   triphase   current,   electro- 
magnetic, S.")7 
Villard,  Soli 

for  r-ray  work,  1U7,  720 
electrolytic,  720 

mercury,  care  of,  727 
dip,  72:i 
jet,  721,  S.")!) 
turbine,  725,  S5G 
principle  of,  720 
rectifiers  for,  723 
Hopiciuet's,  725 
\\ehnelt,  722,  723 
Frimaudeau's,   l'J2 
hammer,   Ml,  112 

Wanner,    with    faradic   cur- 
rent,  15s,   I.V.I 
Johri.-ton,  727 

interrupt  ion-  of,  S57 
I.cdu.  ,111,   15s,   101 

liquid,     1    15 

mechanic,   1  I  1,  S54 
conden-er-  for,  s57 
mercury,  can-  of,  727 

jet,  725.  -.511 
turbine,  725,  S5(i 
metronome,    lor    tiiuiti^    my- 

ojiraph,  ,'ils 
pi-tnlulutri,    tor    timing    myo- 

trraph,  Mis 
polaril  \   of,  ,  21 

(jllc  -en    \  ibtatilij.',    S51 

ribbon,    1  12 


\Velinelt,    510 

.  t!i'  n  w\  of,  i :',(', 

in     ciitaneoii.-    application- 
:;si  I 

parnll.  1.'  rapid    r'adioirraph> 

v.ith.  71! 
/-ra\   wall  m-t  a  Hat  ion  with 


Interrupterless  x-ray  apparatus, 

Kny-Scheerer,  747,  71S 
Interrupting     handle     for    elec- 
trodes, 3S5 

Interruptions,  cliarac-ter  of,  S52 

in    primary    current,    rate    of, 

x-ray  production  and,  11114 

of  mercury  interrupters,  Soli 

rate  of,  S51 

Inte-tinal      diseases,      hijrh-fre- 

quency  current  for,  (iOit 
disorders,  diathermy  for,  (i3li 
douches, ^  elastic,  432 
obstruction,    electric   douches 

in,    132 
secretions,     static    electricity 

and,  75 

InteMine,     adhesions     of,     radi- 
ography in,   102(1 
cancer  of,  ,r-ra\    in,   122!) 
effect  of  j-ray  on,  1  111 
finding-  in,   1023 
fluoroscopy,  dangers  of,   1033 
foodstuffs     passing     through, 

radiography  of,   102S 
foreign     hodiers    in,     localiza- 
tion, 102S 
obstruction    of,    radiography 

in,   1023 

radio-cinematography,      dan- 
gers of,  1033 
radiography  of,   1021 

bismuth  meal  for,   1022 
intensifying  ,-creen  in,  1033 
technic,'  1030-1032 
TouscyV  position  for,  1010 
small,    effects   of   stimulation 

of  pneumoga.-tric,  3411 
Intracardiac  electrization,  350 
IntragaMric     electrization,     ef- 
fect.-, 431 
electrodes,  3S5 
Intraspinal    di>ease,    electricity 

for,  515 
Intrathoracic     tumors,     radiog- 

raj)liy  of,   1010 
Inverse  current   in  .r-ray  tubes, 

7O(i,  707 
di.-diarge,  115.   I  1H 

in      radiograi)h\  ,     suppres- 

sion,  sill 

of  r-ray  tubes,  7si> 
regi>t  ration  of,  Mil) 
spark-gap.-  for,  7sH 
ventril  tubc-s  for,  7Sli,  7S7 
Involuntary     mu.-cle,     contrac- 
tion of,  331 
lodin    anaphore-ia    for   adc-niti-, 

Kill 

for  goitcT,   IOC. 
for-    gononheal    arthriti-   of 

knee,  107 
for  tabetic-  arthritis  of  knee, 

107 

for  h\  perth\  roidi-m,  >',:•',, 
ioni/ation     for     acute     ton.-il- 

liti.-.   IO7 
Ionic     medication     b\     electrol- 

\-i-     :-;il!l.       See    al.-o    C,il- 

;,,,w._w.v. 

in  ear  diseases,    131 
imlii  at  ions  for,    11O 

theor\   of  elect  ricity,   111 
loni/.al  ion,  bipolar,  lot  incipient 

cancer  ot   breast,    1O1 
burns  due  to,  3711 
b>    cathode  ia>-,  713 
b\      radio-active     .-ub-tance-, 

'  1211 

by  ultraviold   ra\-s,  (175 
b\    j--ra\  ,  '',' is 
conduct  i\  it  \-     of    liquid     and, 


INDEX 


1307 


lonization,  heat  of,  205 

Johnston  interrupter,  727 

Knee, 

iodin,  for  acute  tonsillitis,  407 

interruptions  of,  857 

fo 

metallic,  therapeutic  applica- 

method    of     immobilization, 

tube 

tion,  297 

1094 

in 

of  air  bv  x-rav,  043 

of  measuring  x-ray  dosage, 

Knee-c 

conductivity,  043,  044 

1155 

See  ; 

over  earth,  5} 

Joint     diseases,     high-frequency 

Knifes 

therapeutic  uses,  013 

currents  for,  583 

doul 

to  render  conductor,  25 
of  gases,  012 

radiography  in,  1105 
injuries,   high-frequency   cur- 

Knock 

by  channel  rays,  713 

rents  for,  583 

1075 

bv  ultraviolet  rav,  643 

Joints,   oxygen   injections   into, 

Kny-S 

by  x-ray,  013,  098 

1074    _ 

x-ra\ 

conductivity  of,  043 

rheumatism    of,    radiography 

Kodak 

processes  for,  042 

in,  1115 

Kroma 

of  salts  in  cells  effecting  stim- 

stiff, static  wave  currents  for, 

ulation   of   nerve  and   mus- 

74 

cle,  331 

tuberculosis    of,    radiography 

Ionized  gases,  electrolytic  qual- 

in, 1120 

ities  of,  Oil 

x-ray  for,   1  IS!) 

Ions,  2  IN,  012 

tumors    of,     radiography    in, 

fixation    of,    in    tissue,    after 

1  1  05 

cataphoresis,  100 

Jones'   (L.)  table  of  duration  of 

large,  produced  bv  x-rav,  698 

condenser  discharge,  390 

LAC-RIN 

metallic,  259 

test   for  paralysis  of  serratus 

elect 

migration      of,      static      elec- 

niagnus, 478 

Lalaiu 

tricity  from,  55 

Joule,  172,  371 

I.allem 

negative.  043 

Joule's  law,  215 

work 

reduction  of,  in  electrolyte, 

Lane's 

25!' 

put 

of    metal    electrode,     passage 

KAISKK'S  blue-light  therapy,  087 

I.anolu 

into  electrolyte,  259 

Kanalstrahlen,  049,  712 

1144 

positive,  043 

Kaolin  electrodes,  3.82 

Large 

and   negative,  at,  same  dis- 

pads, 382 

au 

charging  point,  320 

Kassabian    tropical    developer, 

Laryn^ 

oxidation  of,  in  electrolyte, 

890 

rent 

259 

Kathions,    248.      See    also    Ca- 

Larynx 

small,  produced  by  x-ray,  09.x 

tions. 

transportation  of,  rate,  400 

Nations,  248.     See  also  Cations. 

hi 

velocity  of,  200 

Nave's     halation     experiments, 

in  electrolyte,  201 

793 

rei 

in  gase-,  201 

Keating  Hart's  electrode  for  ful- 

X- 

Iontophoresis,   chlorin,   in  rheu- 

guration, 502 

dise: 

matoid  arthritis.  41  1 

fulguratton  for  cancer,  501 

99 

for   sterilizing   root    canals   of 

Kellev-Noett    titubator,   8X3 

norn 

teeth,   105 

Keloid,  electrolysis  for,  418 

para 

Machado's    table    of    indica- 

galvanic current  for,  427 

pin  i 
t    i 

tions  t<  ir.  -110 
Iridoplatinu  u     n  lie    for    gal- 

.  027 

T  11  oe 

vanopuncture,  410 

radium  rays  in,   1270 

Iris  diaphragm,  791 

static  electricity  for,    127 

In 

effect  of  r-ray  on,   1  139 

thio-inamin  for,  027,  1170 

Iritis   from   ultraviolet    ray,   0x3 

x-ray  for,  027,  1  170 

.r- 
1  atent 

machine,      influence      of, 

so  ution     expo.-ed    to     radium 

perit 

122 

rays,  1  L'O.X 

tii 

soft,  1  17 

Keratitis    from    ultraviolet    ray. 

Int 

in  primary  coil,   1  5, 

0x3 

electrode    amp,  007.  OOx,  009 

Kerato-is,    high-frequency    cur- 

La t  era 

for  electromagnets,    113 

rent  for,  021 

og 

magnet  i/i  n  g  effect  of  dynamic 

X-ray,  lanolin   tor,    1111 

plan 

elect!i'-it\    upon,   107 

Key  receptacle,  20, 

parti'-le-     n    eye,    electromag- 

Kidney diseaser-,  diathermy  for,     i 

net  ic  extraction,   151 

"030      '                                                 radi. 

voltage  re  niired  for,  097 

high-frequency  current    for, 

Isolated    condenser    spark.-,    ap- 

575 

of 

plicatio  i,   195 

effect   of  .r-ray  on.   1111 

of 

induction    .-hock.-,    curve,    of, 

ra  liography  of,   1019 

ixs 

re-u  t-,  looo 

of 

for  facial  paralysis,    172 

tr.  len-ulo-i-        of,        high-fre- 

of 

for  incont  ineii'-c  of  urine, 

quency    current    tor,   5s). 

129 

1  1x9 

of 

stimulation  by,    tx  1 

radiograpln   of.  1O01 

of 

Leyden  jar  .-park,  application, 

x-ray  in,   !  1x9 

of 

190, 

Kici  bock'-     quant  itometer     to     j         scler 

Isolation     of    calorific     ray-    In 

measure  x-ra;.    do-age.    1  15s                        51 

qua'-!/  len-es    005 

Kilowatt.   172 

Law's 

L-oni'.-tnc  contraction,  :;10 

Kilowatt-hour,   172 

volt; 

I.  -'  itonic  contract  ion,  3  1  5 

Kincte-  ,-nerg\  ,   171 

chan 

It'-hing.  x-ray  in,  1  17s 

l\t:e-.     anteropo-ierinr    radiog- 

Leach'- 

raphy  of,   Hi7:; 

Lead    b 

arthriti.-  of,  gonorrheal.  iodin 

diapl 

.1  v\ys.       See  .U./x-V/,,. 

anapliore-i-  for.    \(\7 

lejunum,  radiography  of,   1020 

nitoro-cnpy   of.    1O72 

s] 

fellinek'-  ob-ervatio,,-  on   dec-              hydro-art  hro.-i>      of,      faradic 

Leaker 

trical  accident-    35O-305                                 uiTent   for,    120                                              ilc 

Jelly  electrolyte,    2O  1 

oxygen  injection-  into.    In,  1         .      Leathe 

John-ton  !!uoro-cope,  71o 

radi  'graph;,    of,   1072                                ray.-, 

Knee,  radiography  of,  exposure 

for,  812 
tuberculosis    of,    radiography 

in,   1  120 

Knee-cap,  radiography  of,  1071. 
al>o  l'ot,-ll,i. 
switch,    130 
louble-pole     connection.-     in, 

223 
Knock-knee,     radiography     of, 

1075 
Kny-Scheerer        interrupterles.s 

x-ray  apparatus,  748 
Kodak  film  for  radiography,  s()x 
-r's       mercury       vapor 

lamp,  072,'  074 
for     diseases     of     skin, 

090 

for  trachoma,  090 
therapeutic     u>e-     of, 
690 


INDKX 


• 
Le    (  '      :.    he  -  -  11,  "1 

•    •  is    :'..r    low-ten- 
sion int.  rrupti-el  currents, 
I'M 
to    te-t    mu.-cular    contra. •- 

•  •  .    t."i7 
current-.    |sv.    I'll.   r,_'s 

.     devi  lopinent     and. 
I'.U 

•ter  of.   1''2 

development    and.     l"t 
di-ael'  ant  ure  -      I,    I'-:; 
.  ITe.  '   on   rabbit-.    I','! 
elect  i  .  -'.2s 

laraeli"   current    und,    ontn- 
paris  in,    I'.tL',    I":; 

•  •  e-the.-ia,  5:;n 

it  ion,  ,".:;u,  .".:;i 


liter.     1  i  1.     L'.S,     t'.l] 

low-tension  in'errnpte-d  r/ur- 
re-nt  lor  -i  iatie-a,  .".07 

me  tin.'!  of  ondo-opii'  pho- 
totrraphy,  .'.'O 

e-ular  contract  ion,    157 

•  •     iti    e-nt   eii   trijre  'i.mal  neu- 

ralgia, .".01 

Left-]  mile  i  spiral,  matrnetie' 
pol.--  induc.-d  bv  curn-nt 
...  |(r|li  ,,lx 

I.et-al    electrocution,    2!'.-. 

I..  :-•-.  art.  rie  -of,    inji  e-teel,   radi- 

otrraph;    of,   ]  127 
be, we  el,   rail  ..    107.", 

•  i         .p;    of,    M.7.". 

'  .  ,.    LM    ph  -    "'.    1075 

|Us 


apparatu.-,  -t'.l7 
capacity   of,    L' :',."),   2t:{ 

formula,  2-1.". 
charuiiu.',  20,  210,  211 

formula',  2 !  1_ 
di.-i'harire-  ot".  L'i  ,  2S 

etTe-cts  of,  27,  W.I 

on  blood,  :;12 
from  statie-  mae'hine,  .'i1 


o.-e'iuate.ry   nature-,   2H 

in      treatment       by      static 

electricity,    12 
pathologic  'effects,  absence 


potential  of,   2t:', 

ffirimila,  21.") 
shock  from,  27 
.-  ispended,  -park.-  from, 

is 

t  herape-utie-  va'ue,  27 
Li'-hen    planu-,    radium    rays   in, 

rube  r,    L'ah  anic    curn-nts    1'or 
ite-hintr  of,   127 
inin       .-at  aphore.-i.s       for 
iti'hintr  of,   11s 
radium  in.   127(1 

•     tie   elect  I  i'-it  \    tor,    127 


1' 

.  inn  nl    for,   Ols 
.r-rn\    lor.   lils 
Life,  e    .  ciric  th.  '.ry  of,  2(17 
LiL'ht   and  In  at.  nnliant,  lor  ua 
I-.  lisii 

,    -7' i 
iron       •    '  i      eii-i  hare.'.  -,   .".7 

iandar.1   of.   '..",7 
o;  elilT.  ••.  ni   ''olor,  pi-ia  tratin; 
p 


patient        ami       sensations 

alter,   ii.'l 

i  ITee-l    on  ,-\  e,  (is:{ 
markinjrs  in,  :;.".t 
t  ii-atment.   :{."ili 


-ray    in, 
iL'Ki 

Lipmann's    capillary    e-lectre.m- 

.1.1.    171,   17.". 
Lipe.ma,  r-ray  in,   1  17tl 
Liquid   interrupter:-,    1-15 

o-i-tance    tor    (iailTc'-    trans- 
te.nncr,   71  1 

rheo.-tat,  2O2 

\olt-contre.ller,    ISl 


u  in.-  .-tains.   1 1  s 

Liquid.-,    conductivity    of,    1  sO. 
,<ee     al-o     Coinl'iictiritij     nf 

i,,,,,;,i«. 

current  density  of,   ls() 
electrolysis  of,  li-l-t 
potential  uradie-nt  of,  1M 
re  -i-tan.-e  of,    Is) 

peelari/ation   of,    Ls2 
sjiecifie-,    |sl 

Lithia-is,  triphase  cell-baths  in, 
l-ls 


Ids 

Live  wire-.-,  accielent-  from,  .577 
Liver,  e-ffe-ct  ,,f  r-ray  on,  11  in 

h\  pertro])hic       e-irrho.-is      of, 
-talie  wave  current   for,   75 
Local  currents  ot  action,  2.S1 
Localization     bv     trianjrulation. 


ol   !oo  i(_rn   1  u  i.li"-  m   cranium, 

'.Kit,  '.Kl5 

in  esophajrii.-,  '.HH    'M\ 
in   intestines,    MIL'S 
in  larynx,  !t!M 
in  lutitr,   1015 
in  neck,  d'.il 
in  p.-l\  ic  ortrans,   ini'.ii 
in  -toma.-h,    Io2s 
Ma.-ken/.ie  -Davidson    lo- 

.  ali/e-r   for,    SliS 
parallax  methf,d,   sr.'.l 

Touse>V   me  thod  of  ap- 

pKi'njr       radiojrraidiie- 

ali>  .  Mi! i 

-M,    Ill's    me  thoel,    SC.S 

I         ,->•-  m.-tl  o.l,  Miti 
I      e-ali/e  r.  Mack,  n/h  -  I  >a  M,  l-,,n. 


Locolliotof      ataxia.     radium      ill. 

LllIMls,  clirettaL'c  for,  statie  i-lee- 

Magnetic  pole-  induced   by  cur- 

127x 

I  ricit\   alter,    l_'7 

rent     ihrouirli     de\- 

sinusoidal  run-rut   tor,    1  1  1 

er\  themato-U-,  elect  ro    \  -1-  in, 

trorsal  helix,  HIS 

static  spark-  for,  7:; 

1  IX 

through    loop   o!    win-, 

wave  current    i'ur.   ">l.'i 

liiirh-l  'rei|ueney  current    lor. 

10X 

ultraviolet    ra\    I'm-,  Cixx 

lil'.x 

tliroiiu'h        sini.-tnir.-al 

vesical    criso    in,    galvanic' 

radium  in,   127(1 

helix,    ]0x 

current     till',     .11.1 

-tat  ir  elect  ricit  v   lor,    !_'7 

throiiuh     spirals,     ]ox, 

j--r:ty   in,   .11.1,   .102,    1  I'.cJ 

j'-ra\    in,    1  l.M    ' 

10!) 

Lodge's    theory    nl'    transmission 

FiiiM-n  liuht  in.  1  lx:; 

throiiL'h   .-traitrht    wire. 

nl  electricity  through  gases, 

fulirurat  ion   for,  ."iii2 

107 

lilO 

nicreiiry  \'apor  li^lit   for,  (ISO 

liv    laser-    of    v,  ire    about 

valve  tut).-,  (110 

radium'  rays   in.    1270 

'-pool,    100 

I.niiL'itiiiiinal  rrartii.n,    till 

uviol   lamps  for,  lix'.i 

position   ol,    when   stniiirht 

Loofah    spnnire    with    compres- 

vi  Ijiaris,   iii^h-frequcney  cur- 

wire    passes    under    iron 

sinii  diaphragm.   70ii 

rent    for.  (121 

bar.    107 

Limp   of    \\  ire,    current    tlirouirh. 

phototherapy    for,   (17(> 

properties  of  voltaic  cell-,    1  |ll 

pnsit  inn  nf  masr.net  ie  pules  :n- 

ultraviolet    ra\-  tor,  (17(1 

rays,  ii.1O 

(llieeil    li\-,    10s 

z-  'ay  in.    1270 

reluctance,   1  1  1,   120 

I.iivil»>iul-(  'nrhett      tintometer, 

Luraschi's    method    of    i  iea.-ur- 

unit  ol,    120 

1  1  .1  x 

ini:  r-ray  dosage,  1  135 

riim    transformer,    dosed,    to 

Low    arterial    tension,    hiirh-tre- 

Lux.  (i.-)7 

reduce    trol!e\-car   current, 

i|uency  current   lor,  .127 

L\-mph,    electric    resistance    of, 

2  1  .1 

potential    wave   of,    27.1.      See 

M07 

whorls  about   current  of  elec- 

also  »'<(«'  of  m  nut  in-  mria- 

I.\  inphan^ioma,  electrob>is  for, 

tricity,    1  10 

tiiin. 

'  in; 

Magnetism,    Ampere's    theon, 

l-ray  tubes,  70:> 

Lvmphatic     elands,     etTects     of 

1  1  t 

're-nits  from.  S}|> 

x-ray  on,  1  b'17 

elect  ir  currents  from.   1  !(> 

Low-ten-ion       currents,       death 

mediastinal.    tubercular,    x- 

elect  ri<'it\-  and.  n-la'ion.   H  '7 

from,  :',(17 

ray  in,   1  Ixx 

remanent.   1  1  1 

effects  of,  203,  201 

of     neck,     tuberculosis     of, 

Mairnet  ixins.'  durini:  flow  of  cur- 

on  blood-pressure,  201 

.c-ra\    in,   1  lx(i 

rent,  1  10 

on  lieart,  20  i 

pulmonary,  fluoroscopv  of, 

etTects   in   power-hoiiM--,   2H1 

on  respiration,  204 

lOOx,   loon 

of  dvnamic  electricitv,    107 

tetanus  from,  201 

ra.lioL'ra)ili\-   of,    1OOS 

Mairneto'cathodic  rays,  (1.10 

unidirectional     undulatorv, 

tuberculosis    of,     .r-rav     in. 

Magneto-electric  ma'dunes,  1  17 

too 

1  lx:,.    11  Ml,    11x7 

iron  core  in,   1  22 

interrupted    currents,     I.educ 

Lvmphosarcoma,        x-rav        in, 

MaL'iietos:rai)hs,  (lox 

apparatus  tor,  401 

'lio.s   l-';i:> 

M^Mgnetolnotlve    torce,    unit    of 

Lower    extremities,    fluoroscopv 

120 

<:f.    10HX 

Mairni:\-ing     fluoroscope,     Tou- 

paralysis  of,    Ixl 

sey's,  !<21 

radiography  of,    lOtiS 

MACIIAPO'S  table  of  indications 

Make    -hock.     etTects    on     heart. 

Lumbasro.  faradisation   for,  .110 

for  iontophoresis.    Ill) 

:;7! 

galvanic  current   tor,  .10,1 

Maehe   unit    of   radium   emana- 

Make-and-break  current-,    I:-',! 

high-treiuiencv     current     for, 

tion.    121  17 

Makinir     of     current,     contrac- 

.i'.i:i, ,104 

Machlett's  hiifh-frequency  .r-ray 

tions  at.  :•;:;! 

statie    electricity    for,    77 

tllbes.    7li(i 

Malaiiuin'-  transformer.  7  (('. 

Lumbar  reirion,   muscular  rheu- 

water-cooled .r-rav  tube,  7(i:-', 

Malingering     in     hysteria    after 

matism    in,    salicylic    cata- 

Mackenzie-Davidson     loralizer, 

injun  .  M'M; 

pliore-is  for.    lO'.l  ' 

S(i4 

in  paralysis  after  injiir\  .  :!!ili 

sprains.  electricity  for.   loll 

Ma.-kerel     brine    for    chilblains. 

Mamaral     depre.—  ive     insanity. 

vertebra',  radiography  of  ,  10(17 

(12(1 

electricitx-  for.  .122 

Lumen,  <>.17 

MacroL'lossia,      elcctrol\--is      in, 

Marble,     insulating     proper;  i.- 

Lumiere  Sitrma   jilates  for  radi- 

420 

•if,     lo-s    111'.     22.1 

ography,  xi  m 

Matrenhhise,  HKil 

absor))tion     of     moisture     liy, 

Luniinosit\      test      in     eye     dis- 

Mafrne-ium  c:ita]ihi  uv-i-  for  tia1 

L'_'l. 

ea-es.    :',[>'.',.    .'-'.'.I  I 

wart-,    (Oil 

Marconi      wireless      telegi  iph    . 

Liinisden's    method    of    measur- 

for funi-ratiim  wart-,    1O(1 

,1117 

ing  voltage,   1'.I7 

Mairnet,   Hi7 

Marey's  dnitns,  JJlfi.  3\7.  :',!x 

Lung    abscess,    pleural    eiTu-ion 

attractive  force  nf,    1  1  2 

Mane    and     Hibaiifs    table    for 

and,        differentiation, 

deflection  of  cathode  ray  by, 

-tero-copid    radio'Tapli-       x]il 

1010 

fiJS 

Marker,  lead,  t'nl  plat.-s.  xjo,  x20 

thirkeninir     and.     differ- 

lifting pi  WOT  of,  1  12 

Maniui  '-   tri'at  iiH-nl    for   inc.  ,n- 

entiation,    HUH 

p..  i  -  of,   107 

tinelire    I    '     lirille.      12'.' 

pneumothorax    and,    differ- 

rintr.      do-ed,       transformers 

Marmw,     effect     of     j'-rav     on. 

entiation,    lOO'.l 

and,   120 

1  IM'i.   11.-17,   1  1  12 

radioirraphy  of,   loo'.i 

Magnetic    effect    of   discharges. 

Masking    of    wave    ot    n-gative 

ape\  i>i,  tuberculosis  of,  lull 

.-|."i.  .'ill 

variation     by     superposition, 

diseases,      costal      aiiL'le     and. 

::•     1,     separation     of     radium 

27  x 

1  00  1 

ravs  In.   1211 

Massaire    and    radiant    heat    for 

hinh-friiiurni'y  current   1'  ir. 

l!ux,  1  1.1,   1  I'1 

cicatrices    of    war    wound-. 

r,(  17 

id  linition,   120 

llxii 

eti)|i\  ema  of,   radii  nrraphv  i  if, 

direct  ion  i  if  line-,    1  1  i 

auditory.    Ixll 

l(ii:i 

fonuula    of,    120 

electric,  in  rhi  umati-m,  (102 

flllor  pv  of,  'l'n; 

measurement    of,    121 

vibrator  for.  (1O2 

•    bodies  in,  railiimraphy 

i  ,f    -;  ,  p-di  i-,\  n    '  : 

:    •   ;     n  c  inj  11  ies,   17,1.   :.12 

;:.,   101.1 

]>,:, 

in  -   i  a  t  i  i  i  ,  .110 

1\  n.pliat  ics  of,  fluoroscopx   of. 

ui  it   of,    120 

•       i    tro  Ii  .   i:; 

IllOx,     llHI'l 

in.  rtia.    1  1  1 

static,    for    iii'iirastKenia.    121 

radio!'raph\    of.    IIIH-N 

i  lie.  a-tatic,   17:; 

MUSS,    X    '-        method        of        ,:. 

ntdiuirrapliy  of,  H'.i'.i,    lnn2 

elTects     ol      ,lynaii;ic     elee- 

ralai-  hor.-i-,    (O2 

.   loir, 

.ln7 

Ma-toid    cells.    radioL-ra] 

die;        1,  test  of,    '.MIT, 

17:; 

on; 

tumor-       '.     •     :      rraph; 

(u  mi              •'  .\.   121 

M  a  s  i     i  d  i  i      .     •      .      •  •     '.:_•'•.• 

HUD 

p  •     -,  ui    t,   171 

it  for,  os,, 

Lupus,      blue-liirht       treatmeti! 

determinat  ii  .n,      mnemonic 

Maxilhe.    tist   il  L-      ':       :;, 

for,   i'Px7 

mi  thud,  lo'.t 

cataphor,-i-  for,    lo.l 

INDEX 


Maxillrr.  fistulas  and  necro-is  of. 

Mercury   vapor   lijrht   for   tuber- 

Milliampen-   and    hack-up    in 

.--  ipliy  of,  1147,  'Ms 

culosis,         larymieal. 

Coolidtze    tube    with    un- 

•' ..-:  p\    "f.  !Mti 

til  17.  tills,  tiss' 

changed    filament    incan- 

int. rii  -:  .    fracture    of,    radiotr- 

pulmonarv,  (il)7.  tins 

descence,       relation      be- 

tapln   in.  '.'  Is 

local  effects,"  (is!) 

tween,  sir, 

radioLTaphy  of,  '.ui., 

therapeutic  u-es.  tis'.i 

in  a  jras-filled  tube  with  un- 

r;i   •    -is    nf,    rai  [ii  _••:-.;  '!iv    ..f, 

vacuum     tub--     as     double- 

changed     vacuum,     rela- 

''17. '.'Is 

current   rectifier,   llil 

tion  between,  Mil 

-  i-     'ina  •  >:'.  .."-ra;.    in.   1-'M_> 

Mc-othorium.   l_'7s 

Milliamperemeter.  Ill),  144.  KM 

Maxillar\  -inu-.  radio!.'raph\  "f. 

cost    of,     ll_'7il 

d'Arsonval.  K.H' 

'•7i  1.    ''sj  .       See    a!->  >    .1  •'•.-•. 

electroscope  test  of.    1L>7'I 

dead-heat.   14  t.   K»:< 

... 

lor  uterine  cancer,  IL.'7'J 

hot-uire,   l.'i-l.  still 

Max.  ii.ua/    >  fli.'-ienc-y,     calcula- 

for  fihromyoma,   iLMMt 

for  mea.-urinn   intensity   of 

tii  ''i.  s7 

Metabolism,'      defective.       hinh- 

alternating:  current  ,  _'l) 

law  .  if,  s7 

ivequeiicy  current  lor,  ,~i7."> 

to    measure    .-treiiirth    of    sec- 

troma^'iiets.  n  1 

eftect  of  r-ra\-  on.   1  1:J,II 

ondar\   current,   1-">M 

M    i     mly's   tratisp.  Ivic   lin.-   for 

M.-taearpal       bone-,       supernu- 

Use  of.     11  t'l 

hip  displacements,   In7'i 

merary,   K)'.i7.   Hl'.is 

Minin  lamp,  tis7 

M    ;  •  ••  '-h     p.'K  .-in.-     generator, 

Mi-taearpu-,    fracture    of,    radi- 

Mirror   Lral\  anometer,    Thomp- 

; m 

ography  in.   1100 

son's.    I'.KI 

M   .-I.  -.  •-  ;  •.._••'.•  f.  r.  tisf, 

radioL'raiihv  of,    lll'.i:-! 

slereo-cojie.    Fifeon'-.    Sl7 

Me  i-  .--  mi  nts,  <  '.  I  ..  S.  system, 

TOUSCN-'S   method,    1101 

Mixinu    battery    fluids.    ])recati- 

|s 

tiiherculosi-    of,     radio^rapl.\- 

t  ions,  '.d 

•        trie,  is 

in,   llL'd 

Mm-monic    tliairrams    of    direc- 

..I  v,  I---  in   of  .r-ray.  714 

Metal,  acid-provintr  of.  21o 

tion      of      currents      inducinn 

M-   .-•.'".ru  insulation  re-istaii'-.- 

backin"  for  plate-,  spi 

north     and     south     magnetic 

:       :     .'.'._'!_' 

ball,  insulated,   inside  hollow 

1  10  arity,   Hl'.l 

M-          :          -    .  livalent     of     elec- 

n  eta!  sphere.  -MM.  LM4 

Modern  static  machine,  :i().    See 

,   ity,  !_'.; 

i-onduction  through.  L'."i.s 

also  Xtufir  nuK-fiiii'  . 

.:.'•  rr  inters,   1  H.  s.-,  } 

electrodes   for   hiL'li-frequenc\- 

-toraL'i-hatter\-,  100 

ndensers  for,  s.',7 

work.  .•!•,:'-.  .-f,4 

Moi.-tuie.     absorption     of,     b\- 

•     •   iral     force.-,     -tat!'-     rlec- 

for  recta!  diseases,  f.14 

marble,  L'L'f. 

•    .     •  .    from,  ,">4 

uses,  iist  ).  :-;sl 

static  machine  and.  41 

fee'  it'n-r    lor    alternating    cur- 

electrons,   velocity',    L'lil 

j--rav  jilates  and.  .s'.Cj 

:•:.'-.   in." 

figure.-     for     luarkiiiL'     plate-. 

Molars,  radiography  of,  '.150,  <C.l 

'    -  -  ot  -tatie  electricity,  -"1 

S  J(  ) 

fir-t,  (.i:-i.' 

'  1-     :    mical       movement      '  and 

fu-imr-points  of.  _'0(i 

ower,  !'Mti 

tripii      phase    current-,     com- 

ion-,   pa.-stijrr    of,    into    elec- 

upper. '.i.M_'.  '.'MM 

parison  between,   l-'s 

tro  yte,  L'.'i'.l 

unerupted,     radiopraphj-     oi, 

'.I          n  nerve,  pal    Ksi-  of,    isii 

pa.-safre  oi  .r-ray  throiiL'h,  71  i 

!i.":i.  '.i.'i  1.  '.-i  is 

-tii     ilation  "•.'.  :-isti 

points    to    trace    root-canal-. 

Moles,    iiijrh-fn  quenc\-    current 

M     ..  ,-tin    .        :--.--      mdar\  . 

1  '  '.  \  • 

for,  li-M 

•-•    •    in.   !_'_".' 

sphere.       hollow.       insulated 

.r-ra\    for,   1  17s 

-       .     tuberculosis    01, 

n  etal   hall   inside.   LMM.   L'4  1 

Molluscum   contaciosum,   hifrh- 

r-r:i\    in.    i  1  ss 

wire-,  '-oiidue'  ivity  of,  -M'.i 

frei  iiiency  current   ti  .r,  til's 

tumori      -                •••:!      --11,0-!- 

resistance  of,  _M'i 

Monolith    condensers    for    hitrh- 

trraph;    of,    1O10 

a  .plication.  J1'7 

Rochefort's,  -.'Ms  ' 

M.-di     il    -  '-•    tricit;.  .    defii  . 

oxids.  c-onduction  h\-.  L'til 

Monopolar    taradic    roller    elec- 

; 7 

Melatarsal    hone.-,    fracture    of. 

trode,  Ms.', 

MI            lion  Ir    electrolysi-,  M'..1'. 

radiographs    of,    Ills.', 

stimiilat  ion.  MM.l  .  MM." 

-..  ,.      '_  ,  i      -  -     -       . 

r:uliii>rru]>li%   of,   IMSO 

Moon    vai  mini  litrht.  (\:>2,  o."M 

'.:-•:  .-.  .--•  i\  fib.-.  70:; 

Metol  hycirinnimone  developer, 

Mn,m'.-    method    of    ondoscoj.ic 

•.'                               in.  !:>:« 

ss] 

photography,  ,'.'() 

is,  .    tnpha.-e    baths    m. 

Metric  measures,  J-lnulish  equiv- 

Moriix s     orthoradioprapln      oi 

.  :  - 

alent-.  _'_'s 

heart,   !(l(i7 

•    .   ;'  •    :-  ir,  1M  1 

M.  •  n  'Home       interrupters       for 

Morjihea,   galvanic  cvirn 

•    •  •         itz-1     •  :.      for, 

timini:  rn\oirraph.  Mis,  :-;p.i 

•l.'ii 

'.  17 

Metro-  :  '.  ijiia,       i  i(fh-ln 

-ta1  ic  e!i  ctricit  v  for.  -t_'7 

M-  Mai  di-ord.  i>,  i  i.  "trii  .1;.   for, 

current  for,  ,"s^ 

Morpliin,    n.-rvou's    c'ondudibil- 

"•_'_' 

Ml,  .,  is] 

it\  and.  ::;_' 

fora  n.  en      in      I     tio|_'raph      oi 

Mi'-a  [)  ate-  lor  stai  ic  machine, 

.Mor.-e's  suiL'inu  '  le'-tric  appaia- 

•.     .  -.1.-, 

M7 

tus.    IMC 

'  !    •                    -.-•      -.-.      •  ciiia,  i- 

Mi-    mil            •     .later,   l.'l 

Morton   mi  -hod  .  ,f  seiisibi'.i/inn 

/.      1  _'<,'. 

M    •   •-,-  ..i.  r.-'.  17.' 

i  i.-.-iies  to  licht.  lisL' 

-                         1  -  ,  1      1  I  I  1 

1   •              f  e  1  e  c  - 

\\-\-         e  ]     Tre1    T          1  '    i             "-'    e       'd-O 

.     !0-J 

'  •        .         •     -.-.•-•.   1',.; 

•    •  .  :.  .:..   on,    !_'."'' 

.  -  -          tube     in     epithelioma. 

.    on,   1  1  MM 

IJJ.'i 

-  -      -  -      •     s.',li 

\lidd!.-.-ar'  di-ea-e.    catapliore- 

\1;  ti  •  area  of  brain,  ']•  -truction 

•    •    .        •  •           7  _'7 

•    •      in.", 

A  eil    1          lo- 

-      |,i,    -      7  _'  ! 

-  !    •--:•'       loc  ,]     ,  !,  ,-trii      aiie.- 

evitabiliu  ,  Mil.' 

.    .    . 

••:--: 

cen-il-,   diseases   of,     170 

irrent   ;or,  .Mill 

spinal  paralysis  of.    Is] 



.  ranial  nerves.'dis,  a  1.   I7n 

•    7_'.i,   -  ",i  , 

„;,,,            -,           .     ,,„-,       tit'.. 

•     ibanci 

7  J.  ' 

in.    1  \'M 

'  1.  ctricii\    for.   IMd 

'.'---      •        '        -     .      -.-... 

.....       .             ......       . 

.    -7'i 

I  •  •  -  :  •        1  1  o  !  :  -  ,   .Vi 

j.neumoL'astric 

• 

'  1     ,   -'-'M 

.  Ml'' 

'    ''",,' 

M       -•-•--.      I'M. 
M       -  -            "    ' 

on     MI                        MI  ".-    .- 

.    . 

•   .  •       -.       n    on    

,  ,-lric.    !  _'ll 

INDEX 


1311 


Motor    generators    for    Gaiffe's 

transformer,  743 
for  r-ray  work,  alternating 

current,  740 
direct  current,  7.~>0 
to    reduce    trulley-car    cur- 
rent, 21."> 
nerves,  degeneration  of,  elec- 

trodiaunosis,  3'J1,  392 
excitability  of,  312 
of   lower   ext remit v,    paral- 
ysis of,    IS1 

of  upper  extremity,  paraly- 
sis of,    t77 

peripheral,  diseases  of,  470 
paths,  diseases  of,  electricitv 

for,  51 4 
points,  335.  :iS(i 

value  of,  in  testing  muscu- 
lar apparatus,  458 
polyphase,  127,  I'M 
reactions   in   diagnosis   of   pe- 
ripheral diseases,  455 
voltaic  cells  as  power.  205 
Mottling    during    development, 

890,  891 

Mounting;  prints,  SS4 
Mouth  diseases,  high-frequency 

current  for,  015 
radiography  of,  endodiascope 

for.  771  ' 

radiotherapy      of,      endodia- 
scope for.  772 
.r-rny  tube  for,  771 
Moving       train,       telegraphing 

from.  13:5 

M.  Q.  developer.  SSI 
Mucous     membranes,     currents 

of  rest  in,  271 
effects     of     high-frequency 

applications  to,  509 
electrodes  for,  382 
Miiller  water-cooled  .r-rav  tube, 

703 

Multiple  galvanopuncture,   41(i 
neuritis,    Schmidt     treatment 

for.  502 

sclerosis,  electricity  for,  .".14 
spark-traps,  701,  7M> 
Muscarin,     effect      on     cardiac 

stimulation,  352 
Muscle,  current  of  action  of,  273 

of  rest,  in  271 
effect  of  electricity  on,  302 
elongation  of,  reflex,  .'i  17 
normal,     tonus     rhvthms     in, 

345 
paralyzed,      extensibility     of, 

333 
static  induced  current   for, 

.',  1 3 

polarization  of,  27."> 
reflex  elongation  of,  347 
relaxation    of,    in   stimulation 

of  nerves  of  animals,  317 
voluntary,    absence    of    inhib- 
itory nerves  in.  340 
wave     'if     negative     variation 

in,  271.  270,  27!".  330,  331 
Mu-cular  adhesions,  static  wave 

currents  for,  7  1 
atom  .  -tat  ic  spark  for,  73 
atrophy,   chronic  progressive, 

bulbar  paralysis  in.   170 
fr.ur-cell  bath  for.    115 
progressive,   electricity   for, 
51  1 

abnormal',  "3'Jl'  " 

after  death,  31  1 

atmdal   closure,   331 
opening,   331 

:;t  breaking  <  <\  constant  cur- 
rent. 331 

at   closure  of  con-taut   cur- 
rent. 33] 

by     condenser     discharges, 
ls.5 


Muscular  contraction   by  d'Ar- 
sonval   transformer,  509, 
570 
bv  elect  romechanotherapv, 

'  4  S3 
bv  high-frequency  current, 

'  .509,  570 
bv         isolated         induction 

'  shocks,  484 
bv  monopolar  stimulation, 

'  33  1  ,  335 
bv     peripolar    stimulation, 

'  338 

by  tripolar  stimulation,  338 
cathodal   opening,   331 
cold  and,  311 
curare  to  prevent,  314 
currents   of   action   during, 

327 

d'Arsonval's  method,  344 
Delherm's  apparatus,  487 
designations,  331 
differences   in   electric   con- 

ditions and,  331 
Du     Bois-Revmond's     law 

of,  334 
furadic,  4S."> 

and    galvanic    combined, 

4S5 

anomalies  of,    till 
current    in   testing,  459 
in  myasthenia,  3!)5 
modifications     in     effect, 

4«7 

faradogalvanic,  4s5 
fatigue  and,  333  _ 
from  condenser-  in  parallel 
with  galvanic  currents, 
311 
of  larger  capacity  parallel 

to  patient.  391 
from  drugs.  315 
from  rapidly  repeated  con- 

denser   discharges,    311 
from  series  of  stimuli,  330 
from  stimulation,  313 
Oaiffe's  apparatu.-  for,  4S7 
galvanic,  400.    1st 

anomalies  of,  401 
heat  and,  313 
height  of,  335 
hysteric,     faradic     current 

'  for,  4S3 

in  degenerated  muscle,  3,45 
in  disease,  457 
in  striated  muscle.  32S 
after  death,  31  t 
siibmaximal.  337 
in  unstriared  mu-cle,  3,2S 
inhibition  of,  apparent,  315 
isometric,  3  Hi 
i-otonic,   315 
latent  period  of,  321 

registering.     321,     322, 

329.  3:-i() 
laws  of,  331,  3Mi 
F.educ,    I'.c; 

beL'innintr      of      reaction, 

t'.M 
table  for   mensural  ion  of, 

157 

longitudinal   reaction,    lii! 
maHngeriii!.'  and,  3!)ti 
MareyV    drums    to    study, 

317 

maximal.  335.  33ij 
nien.-uration  of,   157 


motor  point.-  for.  335,  3Si;. 

15s 
nature  of  current   tor,   33'.  i 

o!    int-iL'oni-t  ic  muscle-,  3  17 
of    muscle    -epatated    fn/m 

body,  341 
o-motic      pri's-urc     dunii!:. 

334 
I'fliiu'erV  laws  of,  3S6 


Muscular  contraction,  points  of 

election    for,   335,   .'{Mi 
polar,  nature  of,  :',2S 
(juality  of,  in  disease,   KK) 
(Hiantity     of,     in      di.-ease, 

400 
refractory    period    of,    321, 

322,  320 

resi.-tance  and,  333 
serial,  330 
sluggish,     diagnosis     from, 

3!tl 

stimulation  of,  by  -ingle 
condenser  discharge, 
310 

of  nerve  and,  334 

therapeutically,  483 
strength   of,  335' 
submaximal,  337 
temperature  and,  332 
testing  of,  450,  457,  458 
tetanus  and,  33li 
therapeutic   production    of, 

4  S3 

threshold  of,  335 
tonic,  345 

Tousey's    method    of    test- 
ing,'458.  45!) 
wave  of,  330,  334 

galvanic,  273 
with     alternating     current, 

344 

with  faradic  coil.  100 
currents,  registering  of,  322 
Tchiriev's         observations, 

2s!) 
pains,  acute,  static  >parks  for, 

73 

mild,  static  breeze  for,  73 
rheumatism,         incandescent 

lamps  for,   001 
salicylic    cataphoresis    for, 

409 

sinusoidal  currents  for,  441 
Musculature,    effects    of    .-tatie 

electricity  oil.   71 
M  iisculocutaneous        neuralgia, 

electricity  for.  501 
Musculospiral  paralysis.  47!' 
Mya.-theniu,  electrodiagno-is  of, 

3!  15 
gravis,  470 

reaction  in,  403 
Mycosis      fungoides.      galvanic 

current   for,  427 
x-ray  in,   Ils3,    1233 
Myeliti.-,  electricity  for,  515 
Myeloid   gumma   of  bone,   radi- 
ography in,   1  110 
Myocardium,  effect  of  stimula- 
tion. 352 
Myograph,  315 

chart-  of,  320.  342 

effect     of     speed     of    paper 

upon,  321 

of  temperature  on,  342 
Deprez      electric     signal      for 
timiiiL',       31s.       3111.       :>,-2(\ 
321 

for  reL'i.-terint:  isometric  con- 
tractions. 315 
isotonic  contractions,  315 
Herintr's  double.  32s 
pendulum       interrupter       for 

tmiini:.   3,1s 

timing  mechanism  for,  ols1 
to   register  elei'trometric  cur- 
rents.  32(1 
latent  period,  321.  322,  329, 

330 
tuninir-fork    for    tiii.inir.    31s, 

Myographic  c\irves,  2so 
Myositis,     high-frequency     cur- 
rent  for,  50) 

Mvotonic  reaction.  3!i3,    I1''-' 
Myxedema,  d'Arsoi.v:!   .'.::•  ut 


1312 


INDKX 


X  \'.l    1.7.1    !!\H!'  r's         Illlt  Ilden- 

Xrrvrs,    anlrrior    crural,    paral- 

Xer\-e«,  sensory,  react  ion  of,  40-1. 

-at  1'  ill   .•.•'.    !,.   i  '..;:; 

yr.is  ..;.   1-1 

Sec  a!-o  .-'«  ;,  -../••/  ni-rnx. 

effect    on     wave    .if 

as    I'orcil    rondurtor    in    i-lcc- 

sixth,      involvement      of,      in 

•   •         live    V.'ll  iat  1.  .Ii.    J-.ll 

trotonn.-,  J\.") 

facial  paralysis,  -17-1 

l.i"  ..:  nervou-  conductibilit  v 

auditory,   react  ion  of,  -lo'J 

spma1  acce.-.-orv,  paral\>i.-  of, 

.  .:  u 

ci-rvicai     >\  nipatiiet  ic,      -I  iin- 

17.", 

Xa.-al     deviations,     cle.-troh  -is 

ulation  of,  :-!ls,  :{t'.» 

s]ilanchnic,      stimulation      ol, 

inr.  It'.' 

condenser  di.-charne  llirouirh. 

ira-tric  effect-,  :{.-,() 

poh  1.1.  .  Icctroh  >is  fur,    ll'.i 

.'ill',  i 

stimulation  ot.     See  Xtimtiln- 

.-•  ;••  LIIII,     .1.  •.  :::'  inn.-     in,     cor- 

conductivitv of,  effect  of  cold 

li'ili,    IK  1  inns. 

rected    by    regulation    i.f 

on,  :;!! 

ulnar.  paraly-i.-  of,  -1x0 

•    i-th,  '"._' 

electrotonus  and,  Js  \ 

vapus,  parai.\.-i.-  of,  -171 

radii  .Lrraph  v  .if,  '.e-7 

lo-r-  ot,  from  narcotic-,  iilJ 

\\ave     of     ne^a!i\e     \ariation 

-pur-,  electro'ly.-is  tor,    ll'.l 

in  ane-the.-ia,  :11J 

in,  J7ti,  J7S 

National    Board    <ti    Fire    I'nder- 

cranial,  dix-aM-s  of,   170 

col.i  and.   L'M) 

writer'-      table      i.f      carrv  ing 

]>aUie-  of,  -170 

elTe.-t    of   narcotics  on, 

<-:ipa.  it\    i)l    '.'.  ire>,  JJJ 

current  of  action  of,  J7o 

L'-O 

\    tin  il   Miurces   of  .-tatic  elec- 

current:-   produced    by   cold 

fatigue  and,  2SO 

•  :  .   i  •  '  .  .",i 

applied  to,  :{J^ 

Xervo-st  retching     for     .-ciati.-a, 

X'e.-k       broken       from      diving, 

of  re-t  in,  J71 

r,io 

radiography  ot,  ov.i 

fffccts   of  electricity   on,   :i()l 

Xer\'ou-  di-ease-,  treneral,  elec- 

rail.  -IT     of,      radiography     of, 

excit;i'hilit\-     of,     after     tran  — 

trieity  for,  ."il'.l 

'I'l.". 

plantation,  :-;t»i 

hicli-freijuenc\-  current  for, 

fluoroscopy   of,   'J-s 

at  dilTerent   part^,  old 

5S7 

i'  .n  iirn      In  ulie.s      in,      radiog- 

cold and,  :',i:i 

radium  in,  127s 

raphy  of,  '..111 

clcctrotonus  and,  J-:i,  J-l 

di-oider-  from  pol\  plia.-e  cur- 

lymphatic-    ol  .      t  iiberculo-is 

fati(£llf  and.  :>,\:>, 

rent.-,  i:',i 

of,  j--ra\    in.   11  si; 

heat   and,  Ml:! 

.-inu-oidal  current^  for.    111 

.  :    :•  iniir,   fracture  of.   radiog- 

traction and.  :m 

dyspepsia,    headache    in,    gal- 

raph;,   in,   luiis 

<-xhai;-tion,    in'hicnce   of   cold 

vanic  curn-nt   for.  ."ijti 

iinunitcd,        radiography 

on,  :',\\ 

symptoms   from   s-r;i\,    11  Us 

of,  107J 

facial,  paralysis  of,    17J.      Sen 

system,  disea-c-s  of,  elect  ricitv 

of     uterii.-,    cancer     of,    cata- 

also   Fncinl   n.rn,    pnrnl- 

for,    l.V),  .'.1  1 

phore-is  for,    in) 

.'/•"(••'  ".'• 

effect-     of     electromagnets 

radiography  of,   !ls'l 

Miinulation       of,      for      drv 

on.    I.',! 

.r  of,  i  idiojrrui)hy  of.  (.i'i.~ 

otitis  media,   1M1 

of  jr-r:i\-  on,  1  1  10 

Xecro-i-     and      li-tula     of     ja\v, 

t  nmk  ot,  .-timulation,  o->. 

of  power-house  operative-, 

irraphy  of,  '.H,  ,  '.Us 

CU.-tator\-,  react  ion  of,    170 

Jlti 

coagulation,     in     clc'-t  ro';,  .-i-. 

hypof.'10-.Val,  paraly.-is  of,  4.V) 

peripheral,  di.-ease-  of,  eli'f- 

J'  .  1  7 

inhibitory,      ab.-ence      ol,      in 

trodiagnosi.-,   1  .").") 

of  1,    :..  .  radiography  in,  1  107 

voluntar\-   tnusr-les.,    .".  1H 

Xeuralgia,    blue-light    bath.-    in, 

of  juw.   radiography    of,    '.Ho, 

Latent      period      of,      effect      of 

(is7 

lit  7 

alternating      current      and, 

brachial,   e!ectricit\-   for,   .">0ii 

of  t....tli,  radiographv  of,  '.117, 

'.MO 

cataphoretic         cocainizat  ion 

'.Us 

median,  paralysis  of,  -!-0 

for,  10."> 

X'ecro-perrnia  from  .r-rav,   1  !:».,, 

stimulation  ol,  :',s(i 

eer\-icobr;ichial,      ."ilMl.           See 

1  l.Js 

motor,   exfitability   of,    varia- 

al-o     Crrrirobwhi'il      l«n- 

Needle,      bulbou  —  pointed,      for 

tion.-  in,  '.',  1  J 

r'll'iia. 

.  Ii  •  tr.il.\  -i.-,    ll'i 

ol    lower    extremitv,    paral- 

cutaneous  tenderne--  in,  ."iOl 

.•!<•.  'trod.-',  :ivi 

VMS  of,    1-1 

deltoid,  .".or, 

•    i    .•     •.  inopiiri'-turo,   :-j^:', 

ot"   ujipi-r   extremitv,   i>aral- 

diathermy   for,  C,:',s 

•     ••  •.  17.; 

y-i-  of.    177 

electriciu   tor,  ."ill! 

rli-viation.  in.    I'.tO 

peripheral,  diseases  of,   170 

facial,  el.'-ctricity  tor,  r,01,  .",0.", 

-.  !«•:< 

obturator,   parak  .-i.-  of,    1-.1 

glass      vacuum      electrodes 

X.  L'  ltiv<-  cll-r-tri-'iTy,    Is.    10,    J.!!', 

ocular,      jiara  v.-is.      <jf,      elec- 

for,  .,r,r, 

po!..   ol    ndary    -,:!,    1  tH 

trir-ity  in,    171 

radiographv   in,   diagno-tic 

of  -km.   Ui'.i 
ol    -pel  iiil    -ii-.-     Id- 

value,  '.Hi7 

• 

of  tooth,   radiography  of,  (C,_' 

ultraviolet   ra\-  in,   1  1!K{ 

•  :•  'if,   -.'Ci 

olfacton  .   n-a.-tion  of,    IHs 

r-ray  in,   1  I'.ij 

film,  file  for.  ->'.ii') 

oji!  I.-,   no  -i-n-at  ion  of  li«_'ht    in 

liigh-tre'iuenc\-     current      for, 

.    ,     x  ^.  ^ 

e].  I-T  ri'1     -t  im  ulat  ion     of. 

.)7(l    ."i'i:{    :,'i.'- 

-'<-', 

incande-cent   lamp  for,  Cii',1 

•  •  •     •    •  .-.     •  •  ntuatc    fr-a- 

arrophy  of,   hiLdi-fre<|ueni'.\- 

illterc.i-tal,  eleclricit\-  for,  ."i07 

1  :,'.   -      ''7'' 

curn-nt   tor,  (i  1  - 

rn-rvi-  blocking  in,  Js.', 

-  froi      r-ray,    1111 

elTect    ol   s-r:i\    on,    1  1M'» 

iieuriti-    and,    dilTerent  iat  ion. 

•.    .    radiography  in, 

..   ict  ion   of,    I'i- 

:.'  1  1 

I  in,  ; 

j/hj.-hi.'.  -i  imul.'ii  ion  of,  i'.Mi 

Of    te-ti-,    :,11 

-  -'•'.  '•'•''•  '''''       . 

lor     i-|.|i  irolorm    -;.  ncope, 
1  J'  t 

).'  !•.  ic,     in     iieura-t  hc-tiia,     iii- 
duced  ciii'reijt   tor    ->J1    .,J., 

. 

plantar.  ]    ir.-i]     -i-  of,    1-J 

railium    ra\  -   in.   do-age,    ]  jr,." 

.  '7 

pneumot'a-tric,    fal\  aiiic   cur- 

referred pains  in,  .",()! 

' 

rent     lo,    in    L':I  -i  ric    rii-- 

-'•la  '  1C,    .",(  l7.      See   a  !-l  .  .-'  tlltirfl  . 

.   •    •     i::     nHiralt'ia, 

.-;:  -.  -  .     l.'.l 

static  induced  current   lor,  71 

lion     of,     cITect     on 

-park  for,  .Mi:; 

tion   of,   -tudn- 

heart.    :;"iJ 

Ihermopenctrat  ion  for,   '>'<•> 

• 

va-omotoi       c!T.-ct-      on 

t  :  i'rcn  i  i  na  1    ."i(  1  1     .V  )''      >i  .-  a  l-o 

.  u 

inte-t  me,    :;  I'l 

7      .    '     .   i/  ».  inil'ii'i. 



/    '  i'  .n   o!  ,   J7."i 

\  i,ceral  di-iuibanc,.-  and,  7,01 

•    •     ',,  .;.;! 

i-     ol.      1-| 

..    "i-.     eMimination    oi     teeth 

i:  .  .                                    • 

re||,  x   -Mm   ilation  ol,  :;io 

in'.  .'iHJ 

','.] 

!.;••' 

j--ra;     for,    '.'..; 

, 

.  '••', 

Xeura-lhi  nia,    abdominal,   elec- 

•      •   •    • 

tot 

tricit  •     lor,  .'ij.'i 

1.     

:;).', 

Alpii,.-  '-„„  ra\ing  for,  c,!il 

of,    1-1 

i,|.,...|  ,,..  -UN    in.  :,JJ 

.'  •  •  •             :  '    '  .        ' 

•      n      •.-'••"    va.-o- 

c.-rebral,  gal-,  anic  cm  ier,t   tor. 

d'Arsonval  current   for,  :,_>o 
d\.-pep-ia   in,   liiKh-frriiuriu 
cunvn!    for,  o-'7 
it  v   fcir,  .ii':; 

laradic  current    lor,  .")_'! 
galvanic  current   for,  .~>l>."> 
cephalir,.-,:.'l> 

impotence  in,  o-o 


Neiiro.-e-.        occupation,        elec- 

I  ricit  v  for,   "ill  i 
Neiiro>thenia,  .V.M) 
Neurotonic  n-:n-tion,    liiii 
Nculr.-il     win-     of     electric-Unlit 

r-ervice,  _'n7 


i-urrent    for,   ">!' ! 
piiciinii>L':i>tric    n;ilv:iniz;il  io 

for,  .li'il 

.-inu-oiilal  currents  for,   I  I  1 
static  l>:ith  for,  ">L':i 

luve/j'  tor,  .'>L':i 

electricity    for,   .")_'•; 

friction  tor,  .">24 

inilii'-eil  current  for,  "i- I 

itir-uiut  ion  for,  ")2:i 

ni:iss:ij£c  for,  .">2  1 

spark  for,  o.'l 
urine  in,  o_'_' 


in,  l-'i:, 
Niton,  1L'.-,1 

atomic  theory  of,   1  _'.M 
Nitrates  from   iitniospheric  air, 

means  of  olitaininu,  "is 
r-ynthetic  maniifact  ure  of,  .">7 
Nitric  acid  a>  electrolyte,  '.'!_ 
from  stal  ic  (ii-cliarj.'!'.   ~>7 

ton. i'  of.  liot 

i'Xcn-1  ion.  jr-ray  and,  1  l.->'i 
Nitn.iren-fillcd     'electric       H-lit 


Nil  r-. .   Ken  tulie  rcpuluti  >r,  ,  li'.i 
tests  of,  by    Mutscheller, 

"(5(1 

.r-niy  tube,  7*'^ 
Nitron.-    acid    from     ultraviolet 


(  ihmic  resistance,   ")'.> 

electricity  lo-t  liy,  -'Hi 
of  voltaic  cell,  !M| 
(  )!d  grains,  x-ray  in,  ll'M 
(  Heat.'     of     mercur\  ,     raduim- 

i  I'K  cran  in  pn  icess  oi   ulna,  fi  ic- 
ture  of,   radioj:ra]iliy  in,    ln'.i'.» 
I  ilfactor,    centers  of  brain,  elee- 
tric  -timulation  of.  :;.",:; 

(  indotneter,    Kerri<>'s,'  o!7 
()n.lo>cop(.,  7!H).      .-,^a;-.-"        - 


, 


-i  'i-is      •  it.      ..,:•(•  tre-         '  '•••-.     di-ea-e-  oi  central  rier- 
ie  \\  ave  cur-  !  •  •     '      >r,  i'<_'l  -          ten,,   electricity   for, 

\     !  -.      l^'lll  .'.I    i 

h-  in.   HS  N       •    .•  oi  ,  ,  11  ii  i  .  \,  ,••,,„•    -,,•:  .         I  irtl  -    •  '•     .  "'.'7 

<•'  mea-u:-e'>i/e  ol  heart,   Ino7 


X  n  i  rit  ion,    1 
./--!!>   for,  :>.W  1") 

N     .  .  ,     '      ;•..••. 

Lralvanii1  i'U  r  rent   in  I"-t  itiL*.         '  'Hi  -I  rv.    I  '••  rironie'-    tn   itn 


te-tinir,   I."1-.   l.V.i 
•     •  -    I       •    .  •    •     lie,   loo 
[i     •     •    '     -  .         •        it  ion     in, 
maintenance  of,  31  ! 

complete.  :;il 

,   I,  pie.  ,;il 

v; 


t'rtl    ii.hot.iLn-aph;        ,  : 
it     i  Moritz'-.   lon7 

.    :j-  Kii  d,  r'-.    loos 

'     '  •  '  '      .  '         :     :     :   p.  ... 
HIM 


• 


INPF.X 


(i-:.     -:-,  J."i  1 


•.•'-.:  rapln    in, 

.  j-r;i '.    : :  .    1  _'->x  '  "  :  :    "      :. 

(  P\ 


ill 


liijih-I'r('(]U<'ii'-y     rurrcp.t     for, 

.V.I},  .")!C),  .V.'li 
I'alutt  .     luird,     i';iitlif!i(iliiH     "f, 

.r-ru\    in,   iL'l.'i 
Milt,   p;ir:i!\M-  uf,    171 
i  ••••'. '.-   ii  clinic  fin   j-rav  in 

.  ::  :,:'.    iLM  ii 
Pap  !.   !,r.,iiii<l,   Mid,  ,vs-l 


P:il,iilon,;i  of   lilat'.fli  r,   hi^h-frc- 
<;i!i  ncy  r-}i:irk  fur,  .>o 

lailiun,  for,  1J7  1 
I'aqui     :    -      liiini       fin      !.!•:!' inc 

•  .-men  f£ul::t(jr,  Ttil 
Pi'.rtiholii'  rctici  tor,  (i.">!l 
i '  ••    1:1  i!i  -'•  •'.'•  '  Ii  '.  cli  'Mni:  tank. 


ftcr   ii      '    .   h\>tcri;j 
ii.  ii;     injrci  inp  in,  --i'1!) 
aL'itan-,    liit'h-l'rcijucncy    cur- 

n  n'   lor.  .V.il 
}'      '.-,  clcdii   it-    in,    172,   17:; 


Diii'lii  tin.    i  rh's,   17-,   17(1 

.   .  .  tricin   i''.   1  .')."> 

1. '}•'-.   !7s,    17!) 

:         !.  .-tatic  .:  :;\  i   curn  ii;  for, 

17:; 

:  nadic  (  nil  for.   K'.O 

Irol      :       ::';:-.    \~~>,    17o 

-••.nil 

:    •     •      •    :..   17c. 

.  ;      -        •     •        -i,   and,   dif- 
;.  :,  ntiatioii,    170 

.:••:.•      I'or, 


ntci  r  ci  iial,  1^1 
:  .  I  7  >  i 
.  170 

dir.jihriit'ii  .  radiotrr;  : 
1  I'll  1 

:•••..    172.      Si  c  :v      . 

/  I    •..•••'. 


1315 


Paraly-i-of  infraspin.ltus,   ITS 
of  fan  MX,   I7t 
nl   lower  extremity,    !sl 
nl  median  nerve,   'so 

111     motor     niTYC-     lit     lo-Aef    CX- 

Uemities,    isl 
i  if  upper  exl  remity,  -177 
«t  obturator  n,. rv,  ._  |s'l 

111     ocular    nerv-,     !  .    1 

electricity  in,   171 
.it  peroneal,   1*1 
ot   popliteal  nerves,    Isl 
n!'  sciatic  nerve,   Isl 
.if  serratus  ma-mus,    !7s 
.  :   -i\th  nerve,   171 
of  soft   palate,    17! 
nt'     sphincter     ani,     hitdi-fre- 

i  lueliey  curret:!   for.  olM 
1 1|   .jiituil  accessory  nerve,  17") 

motor  centers,    IN! 
nl'  -ternoma.-toid,    177 
nt  siipraspinatus,   17s 
u!  thinl  nerve,    171 
of  trapey.iu-,    177 
ut  ulnar  nerve,    IM) 
,  ;     ipper  i-xtremily.  -177 
cil    va<.MIs.  nel  ve,    171 

i  rtranie,  -I7ii 

funct  lonal     paralysis     and, 

differentiation,  I7ii 
plantar,   >s2 

lobulbar,   in:;.   17>i 
respiratory,   from   alternating 

currents,  M7M 
from   hiL'h-ten-ion  current, 

sinu-oidal  current-  for,  -1  11 
slow    sinusoidal    current     for, 
1  ID 

Paralyzed    muscle,    exercise    of, 

I>v  stal  ic  induced  .-park-, 

.VIM 

extensibility  of,  MMM 
from    \\ar    injuries,    liipolar 
static    inducto-resonator 
efiluve  for,  7ti 
Pal  Liiiafriu  ti  •    substances,    121, 

122 

Paraplegia,  electricity  for,   ">!."> 
Par!.in-on's     disease,     atit 

duetion  for,  ."."1 
Pa-tinn      storage-battery,      10(1, 

101 
Patella,   dislocation    of,    radiop- 

raph\   of,  ID,  :, 

fracture    of,    radiography    of, 
K)7! 

f,    1074 
•    !i   x    after    lic;hi  iiii,<_'-st  rok<-, 

:):,! 
late  appearance  of,  electric 

•  •':•,.;  I , 

Pe:i"U    in    oy>ter<,    radio_-rapliy 

i  :.  1  i:-;o 

,    .       .      .      ;       .      .    ..       .  .    , 

of,    for    chlon  ili  inn    s\  neope, 

42!  i 
Pi  d  incul.-.tcd  warts,  electrolysis 

f  i   ' .    1 1 !  I 

Peltier':-  cro-s,  2'i! 
Pelvic    hones,    radiography    of, 
Kit  Hi 

•    ,     I  •,',:•:.        h;    ...   I 

statie  ,  :      ••       •       tor,   7! 

C'XtH  late.-,  lii!_'!i-i  i  ".  lueney  cur- 

: . .    .'.'/;.::.   i ,  i    . :     -'..-• 

:      u>,     :    •  •     .  •        vapor    li^ht 

i'            :       '  f.  1(117 

radiniri  ip    .    ni,  1017,   Hi'iii 

in    •  ir,  M2 
PI  :i.p!ii        .     •    • 


Peni-,   ejiit  helioina   of,  .r-r:r.    in, 

1217 
Percutaneous     eli-c'  ri/at  ion      in 

Perforatin;;  nicer  of  loot,  faradie 

curn  nt   for,   J27 
liit'li-freinienev       r-nrrenl 


in.    I  IM; 
Perincphritis,     r!i<Iii>irraphy     in, 

1  i  n  i:  ; 
Periostea!  piinnia,  radiography 

in   !  I  10 
Perio-ti!  i-,    hiuh-fri'iiuen. 

radionrapliy  in,   1  10s 
.r-rax    for,   liljij 

Periphi'i"!  1     nioti  'f     ic  rve-,    di.— 

eases  of,    !7O 
ncv\,'  trans])!antatiori,  excita- 

bility  after,  :;io 
Ui'tiriti's,      alcoholic,     i  lectro- 

diaL'iio-is   in,   :'}'.>'> 
.-en-orv     nerve-,     diseases    of, 

170 

PC  ripe  ilar  -t  imulat  ion,  M:is 
Perisiaisi-.    hitrh-ft  >•'  :;i-'iicy   cur- 
rent for,  "i71 

llation  of,  before  .c-ra\    exam- 

ination  of.    101s 
Peritonii  i-.     t  ul  ii  :  cular,     r-ray 

in,   1  iss 
Perinaneiit    teeth,    r:idio::r:iphic 

inea-iureiiiont      bffort-      c  ni|i- 

i  i.  ''.,   o.-,.- 
Pernicious    anemia,    clijihtiieria 

ant  itoxin  in,   I  I'.is 
x-ray  in,   ll!»s 

Pcroneai  paralysis,    Is] 
Perspective    in    dental    radioir- 
iy.  il.Vi,  !ll)4 

Per>pira'ioii.    effect     on    plate-, 

SI!),   VI2 
from  c-oi  :ir:il  stitnulat  i>  in.  '.'>  10 


PliaL'i'dcpic  cliancrc,  cocain  eat- 

iresis  in.    till 
corro-ivc'     -ublimate     cata- 

piioresis  ill,    1  1!' 
Phalitnire-    ol     :'.,.'.    •  I.-    :  ...    ni, 

•     :-..      in, 
IDS.', 

• 

,.  ].;.    of,    1H- 
radii  iL'raph\    .it.   1  1O2 
radi  i      :       f. 

!':  :     •.-.        •••.,..-. 

I'iil'eb  '          i'.-r  for,  lor.s 

.  :  ..r 

!':    mi.L'i-ap'h   :  .-  .:•   ifn.  --.    1  si  I 

•   .  -To 
Pin.-],:      '  '     .     .     :     " 


-ur,  -.   l.'Ms 

Pi     •      .    .     '•        -    ••     '  •  ..-.   i'.  I  ! 
i        •      -in                  ' .  .     •  '.':•  '•'     of 
l.cyd ..17 


Photometer  irrease-spot,  Oo8 
Phototherapy,  ll.V) 

I'.i  ri"i:in'-'-      act  mometer      in, 

i  ir.T 

colored  screen.-,  for,  Wr, 
disea-e-  benefited  In  ,  Uss 
•  L'esI  ion,   '.7, 

t.  .1     kin  diseases,  !L'S,  r,7r, 
for  -mall-pox,  o7'i.  i;si; 
physiologic   etfects,   .,77 
prmcipli  -  of,  r,,o 

liM 
Phrenic    nerve,    stimulation    of, 

MS.', 

for    chloroform    syncope, 

1 L" ' 
Phy-ica!      reconstruction      after 

vVar  injuries,  -lol 
Pli;  ,  .i,l.  .trie     ellects,    secondary, 

ol   .!;  itherm;,  .  M\ 
of  ele.-i  i-i'  ity,  _".':-',  •'<  i~i 
density    of    current    and, 
Ml  12 

rela  ;  "  .n  of  ampcrat-'c  to, 

" 


nttanl  arc  Ian, p.  l,l,!l 
electroscope,    I-".:, 
!.-.  ]  ii-rstal  ic    tran.-foriner,    70, 
'  .'  ;  7 

•  ion    i.i     ( i,",rl    ultra- 
violc  t   lamp,  i;7D 
:  Ti  -la  apjiaratus,  .Vj] 

PIL'I  mi's       mirror      stereoscope, 
s]7,  vis 

HS 

.r-ra\   for.  11s 
Pin  is:  i -si  •]  iliajiiis,  !I'.)M 

in  larynx,  localizal :  m,  !|l|l 
I':-     In  les  in   jilatc-.   V'l 

m  radioirraiihs,  s7  j 
Pifchbli  tide,  radiui      i:..    121!) 
:  .     itraction  of,  b\   •  Ii   •- 

.1    bin  i \  ,    21 1 

.  •    i     ir-  of,  radi- 

h  •  tli,   Muoro,  'iijiy  ,.'.  ol'.» 

1  'lam  ' '-  t.  ''I.i,  v  f.  if  faradie  ciir- 
renl     •    '      Intrt hro-i.-     :  knee, 

P'  mi  ir  pa1  d\  -:-.    'sj 
PI    -  (,'•  ~:- ;i-i.;.  -batti  rv,  W 
Plant  -.  •  u'rn  nt  s  of  a    •      :.  in,  2s] 
:  •    t    of  bet      ra\>  Iron     ra- 
on.    12110 

-  •  •  idii-.in  on,  12HO 

...          .    •   '.     .       |  _'.  ,M 

•        '  •     -.:..!!.._ 
electricity    ill,   ."  I.    _V>,  ,    J'N 

:          !.'       -    •  .  :  i 

•    :-.    .  •',, 

•  •     •  •  •        .   ss.1, 

.   si.', 

aluminum  cas-i  tt<  s  :    r,  s]ei 
Int.  •    I.     in      r 
thiirl  .   1072 


lentil      ition  i.l,  sjo 
•    :d,  s,.7 

•.;,  >!)7 

-  •  .;' 

lie  fur,  si  '•' 

•  .  :  .•   ;•  ir   ii|enti;ic.-it  i  m. 
-._. 

in  hind,  Ms 

II,    n  intact    u  il  li.   sit 
•.sp.i 
I          .    sill 

I  i-!  -nil  -.1  inn  n,  ark-  mi,  sl'.i, 


MT:ifli-lii:irks  nn,  s'.rj 

-  :iml.  M'l 
|)i-i-,l.i!,c,)lii- 

;,,>•    :      vith    nlh.T    p!:,T,.s 
n  .      !i    -.  -I  ! 


:.•  in's  treatment.   ".  1^ 
:  i     nil'.  Snow's  lliethml,  ol.'j 
electricity  for,  .'.11.  .".1  I 
],  ::••;:!;,-:-'  from.    17.').    17'i 

:ilisnrj)1  inn  of,   1  -'<  1 
Polyu-.-tlii-ioscoiH'      ot      Arriiro 


.  [i:i-:.!,i  !i  ctroly-isfni,  H!> 
I',         .....  ,    Mclnto>h, 

I'll' 
I'nij-,  !.  -;•  -n  \',  11  li'tti,  fai'ial  p-ira!- 

:  •  •  .  •  -  .  .    i  7  ! 

I'llphn  of,  ;M 

I'niv,.l;;ii,    iii^!i!at..r-,    re   i>1;uice 
ni,  --'  i 


gradient,   1M 

ni    l.eydi  n   jars,  '21.',  '  ' 
forniiila,  LM.*) 

unit   nt.  -I'.i 

I'oteiitiometer,   I'.'.'i,   ll'ii 
I'litt'.-   di>ea>e,    r:ulioi;r:ipliy   in. 
101(1 

fracture    of    lihula,    radiosrra- 
pli\    in.   Hl7- 


1  i:;:; 
I'reL'iiant     cat,     radiof-'raph     of, 

1  1:11 

Preiiiycoj-i-,  j--ray  in,   1233 
Pressure,  nerve-fibers  of,    Inn 


arcuiL'  in.  7;i  1 
condenser  for,  7:11 
variable    self-inductance 

in,  7.SH 

.-nf:-iron  cure  in,   1  .")7 
inriii.    lilt 

inti  rrupt  ion  in,  rate  i  >'•,  in- 
•    on    i|uantit\-    of 
j-ra\   produced.  !  H',i 
iiatun'  of,   I.V.,  l.'.ii.  i:,7 
,,1       induction-coil.-,       [•011- 

ileiiM-r>  for,  L':;1' 
elleet     dl     cnndeii-er    on. 


;  it.  .  ssi 
!•   -,,!  -n  trie                         p.  I.. i,  sx] 

...  i  ss| 

!•  •  ',(,   e,  II,  'HI 

|.  .....       .          ....   ,|i,_ 

.   .   .   :                               •  ...  ss| 

.  •  ....;..,    •            on.  ss| 


tional  an^le  in.   IDI  I 
healed,  radiography  nf,  IDI  1 
heart   in,   IDI  I 

ill  17.    I  is'i 
merriiry     vapor     li<_'ht      fur, 

1107,  r.i  IS,  li.s.s 
of  apex,   IDI  I 

radionrtpln    in,   KID],   ItKWi,     ;      Kudiatoi   i  .  pe  of  (  'oolidtre  tube, 
'1  1 

idio-a'-tiv..  solution,   I-'.--' 

H  e-,    !_'.;'!,    !_'.",_' 
I'll  etrie  ehar<:e  of,    I  _M  1 
ioni/m«   el-feet-  of,    ]  _'1| 
properties  of,    1_MD 
i|iiant  ital  ire   (e~t .    I  _M  1 
radiation    from,    1 -' 1  1 
water,   i  _'.;,D 

In-  to  measure,   1  Jll 

internal     -trurturc     of     earth 
and.    Ul:; 

.  merit,   !_'!! 

'  tion  i-hamber,   li'ls 
•  in  paral  ive,      in 

l.'H, 

n!   radiun  .   \~SV.I 
test    lor,    IJil 

:.    1J.",7 


liiiih-frcn.ncticy    i-ur- 

ri-nl   :  >r,  iil:{ 
f-ru\    for,    •  !  .  ' 

from  hydro-rlci-trii-  l>atli:  .  I  M 
:  rei  [Hcncy     i-iiri  >  :.' 


>t;i:  ii-  l.ath  for.  7:1 

radium   rays  for,    l-7_  (^uantitonii-ti-r  to  ini' 


Imlhar      paralysis,       Hi.'i, 
17'. 
I'-,  uiloli  ilk.  ini.'i,  .r-ra\   in.  1  HIS, 

IL'IIJ 

.  ,r.  51.-i 
•ri-fn       •  :    ,      i-iii-- 

_'  s 

ii    i       -  in,    ]L':H 
•    •  t  ri     '      :  •• .    •  _'i 

:  17", 


lilt! 


;  . 


s|7,  sl> 

n,l  N  -, •  ••  •    .          .  s  ..; 

•   • .  -  •  •  .  :  •  "_> 

o!       '•-•.• 


1  n. : 


1318 


IXDKX 


•   .    s  _'  1 
irreiil      •  '  - s  ;  [ 

.-;-.-         -    .          |,.:  •     •  ,-,;:,    S 


1 1    •  •  .     I  iuli  t -current   tor,  711 

pi     . : ; .    7  7  1  .    7  7  _' 
•.-     -ur.     n.  Ml,  s.l 


:••.-.   io.;o 

in  an  ;    :  ,:".  .   KUII 
ton      .    1  l_'s 

in   :-••:,-   '   -.   izoiiorrhea!,    Ills 
hypern    -  hie,   1117 
:   .-'  .       i!    .,;.   1  1  1.',    1117 

in  '.:'•.  t.'ll  l."j 

iti-n  .   1  1  Hi 
in  b  -:.'    ill-,-:.-.-.   1  1  1-- 

tumor-,  1  HI:, 
in  l)ov.-li  L--.   1111.  11  I.". 

;         -      -  ,r,,      Ml|| 

•  i-i.-,   HI].-, 
in   bur-Mn<_'  fi      turi 


t  ic  valm  .  '-'o7 
in  i  '.-te,  i-an  hrii  is,   1117 
in  oMeomyeliti.-,    1  1  o7 
in   perforation  of  ,-\  ,-ball.  ("Ill 
in  perinephriti>.   lor,:; 
in  pi  rii  i>teai  minima,  1  1  HI 
in  perio-titi.-,    1  los 
in  pneuni:! '  ic  sinu.-es  of  face, 

iliamn  --;  i  •  \  nine,  '.'lid 
in  imeiiinonia.   loll 
in  postmortems,   1  1  2s 
in  I'ott's  di.-ea.-e,   loir, 

tract  lire  of  fibula.   1O77 
in     pregnancy,      lo:;:;,      10'i7, 

1  l.'il 


K-Oii.    !01  1.      S,-,-  also   I'ul- 

m,,h<ir:,  /-.'.,.'--  „/.,.-.',. 
in  radiil  i-,   \\\-!> 
in  renal  tuberculosis,  Hliit 
in  iheumatic  -out,  1  1  Hi.  1117 
atisn  .an  ii-ular,  1 1  Hi 

nl  joint-,  111.'. 

miatoid  arthriti-,  1 1 1~>. 

1117 

in   rickets,   1  1  l-"i 
in  sco!io-is.  1017 
in   skull   fractures,  '.MIL'.  <»<)! 
in    -pina    vi-n'o-a    -vphilitica, 

1  1  !_' 


m  -t  rictnre  <  <:  e.-i  iphairus.  '.'''  t 
in     sr.pi)iiration     ol     antrum, 

ij.  -•  pi.:'.:-  i  if  1 --,    1  1  H1 

•       -    :     il.-.   111-1 


in  tab,-';,-  joint,   ills 

in  talipe-  ,   mini;-,   losi_> 

in  tutierculo-i-  ol  bone-,  1120 

nl   can. i..-.    1  120 

--:   ,  llinw,    !  12s 

'•.112" 
nf  kidm     ,   KHil 

01    knee,     1  120 

ol   ii  ,-tai  arpu-,    1  120 
in   lun.or-  ol   bom  -.   1  lo:, 

nt-',    1  H'-, 

• .  7 ;  i 

•  .   x.,.: 
it,    IP,     '       ajipar:  tu-    duriiiL'. 

si:; 

::•--.-,,         '  ':         for,    si  1 

-  -     |no:-;.   ii"-:. 


of  innon.inate  arter\  .    H«  ni 

.    KIM) 

of  ank\  !o-i-  of  lower  jaw,  ','i',7 
of   anterior   -uperior   -pine   of 

ilium  in  mu-cular  t'ractuie, 

1071 
of    antium,     '.isl.        See    al.-o 

nl  ai  ,rta,   loo:, 

i  :      aortii      aneiirysni,      lool, 

of   apex   of   h;iiL->   in   tubercu- 

lo>is.   Kill 
ol  appendix.   H'2, 
ol   articulation-  of  lower  jaw, 

of  atlas  dislocation,  '.''.'I 

of   bilian    calculi,    101s.      Sec 

a!-o  li;i;,ir;i  r'tlculi. 
ot  bladder,   lo:,t 
ofl.lood-vessel.sof  chest,  1OO:5, 

1 1 H  >'} 
of  boner-  alter  ca.-tration,  1  HI7 

ol   In  -.:::,  ail    in   ventricles  of, 

'.'i  <~i 
of  bronciii,   1O02 

call  areou-,    100'. I 
of  bronchopneumonin,    lol." 
of  cnlcareous  bronchial  glands, 

KIOH 


pro-tatie.  Kiii.") 

renal.  !O)s.  See  also  L'ri- 

;,-/;••/  i,,\,  nl,'. 
ureteral.  lo:,l.  lO.Vi 

-     -    .  lo»s.   Seealso  I'ri- 

•  .   H"H 

nl  callus  aiti  i    fracture,   1101 
of  cancer  of  bone,    1  1  Oo 

oi  neck,  ''"'< 

of  cafl.ohx  drate.-  in  >tomach, 
102'.' 

area,   lool 

ai    i:.-'--.    loo2 
'-:  carpu.-,   in"--; 
ol  ceciim.   !02s 
i ,:  cer\  teal  ftadure,  '.('.'I 

rib-,  i's'.i 
of  ,-he-t,  d'.i'.i.     Se,    al.-  ,<>•-•, 


K  '-'' 

•  hi     :  :,-   cm  -tipatio]  .    K'L's 

,'   ,  !:-\  :--],-     H  02.    loo:; 

.-,  al  ill-location,    10C.7 
fad    ;re.    loo 7 

-  (      - los'i.  n",'' 

i, .chni   .   io'  o 

T,       -  po-ili.,1 

lo:  II 

,1   colon,    1027 
b\"   lo_'7 


adioL'raphv    of    dislocation    of 

Radiography  of  fracture  r  I 

!;adioLfraph\-  of  metatai  -a!  frac- 

eiii-ej  \,   ]dii7 

toil!   pro'-oss,  '''.'I 

tun  .   ins:, 

of  dhow,    1  Id:.' 

of  patdla.    107.", 

of    mouth,  endodi  i-cope    for, 

of  hand,    1  10M 

of  phalanges  of  ham  .    1  1  ()_' 

771 

of  hip,    KHis 

of  phalanx  of  toe,    K  s:, 

of  na-al  -eptnm    !'s7 

of  low  IT  jaw,  !!''.<'. 

of  radiu-,    lO'.l'.l 

of  neck.  !iss.      See  al-o  .V.r/f-, 

of  patella.    107.-) 

of  scaphoid  hone,  ununitl  'i. 

rmli'o  if  n  ill,  a      . 

oi  radius,    1  lo_> 

1  1  1  10 

nl   femur,    K.I.S 

of  shoulder,   1  lo_> 

of  scapula,   10'is 

oi  obstruction  oi  colon.   ]n_'7 

congenital,    lO'.i.". 

of  siir-ical  neck  of  humerus, 

oi   odi  intoid   fracl  lire,  '.''«  1 

of    divert  icula    of    esophagus, 

lO'.ls 

oi     paralysis     of     diaphra-rm, 

(MM 

of  tar.-al   hone-,    lds(,    Ids.', 

1  00  1 

of  dorsal  vertebra*,   Iddl 

of  tihia,   107."),   1D7H,   1077 

of     patella,      1071.      See     al-r, 

of  dry  pleiiri-v,   lOl.'i 

of  ulna.    Kl'.l'.l 

/'.;'.  II,  I. 

of  duodenum,'  loi'ii.  loi  1 

of  wrist,   lO'.i:),   1  10O 

of  pearls  In  o.\  -ters,   1  |:-;o 

of  car.  '.Mo 

imite,l.    appearances,     1  KM 

ol   pelvis,    !o!7 

Lance's  method,  !U(i 

of    fracture-dislocation    of   e  - 

cxpo-urc  for,  slj 

Stewart's  method,  '.'Hi 

bow,  1  m:; 

ot     phul:iii<;i  -    ol     loot,     KisO, 

of  dhow,    loss 

of  frontal  sinu-.  11(1.'!.  S  'e  also 

Ills.-, 

dislocation,   1  IdL' 

frmit'il   xintt*,   ra<linnr<n>l"j 

of    land.    10!i:i 

expo-nre  for,  s  1  _' 

of  pii  i-holiths,    10.-)  7 

of  empycma  of  IUIIK.  101:! 

of  -rail-stones,    lOl.s,     See  al-o 

of  pii    in  larynx,  !i'.i  I 

of  epiphysea!  injurv  at  shoul- 

Hilary ,-nli-uli. 

of  )>itiiitarv  tumor-,  !'17 

der,   lO'.i:, 

of  L'cnu  valL'iim,   107o 

ol  pleural  adhesions,   ]n]:>, 

of  c-ophaL'cal  dilatation,  spin- 

of  [in-al  thoracic  vessels,  topo- 

i ffusion,  1010.  loi:-; 

dlc-shaped,  !)<J4 

graphic,  lo;):> 

tliiekcniiiK<  Kilo.  Kii:; 

divcrticula.  '.I'll 

vessels,   Kid.'!,   10O., 

of  pl.-un.-y,  dry,    KH  •"> 

steno-is,  !)!i.-) 

of      lifccn-stick      fracture      of 

of  pneumatic  sinu-.  [leeessory, 

of    esopliacu-    with    tuhe    he- 

radius.   Id'.i'.l 

!isl 

hind.    1001 

of  minima  of  hone.   1  I  Id 

t  >po<iraphic  value,  Mss 

of  ethmoid  cells.  !ls!,!is.-,,  '.isr,. 

of  hallux   val-rus,    10MI-lds:; 

of  pueiimothorax.    ldi:i 

Sec  also  Ethnwi'l  ,./'.,-. 

of  hand.   Ids!),   Kl'.i:; 

of  preitiuuit   cat.   1  1H1 

of  exostoses  of  hone,   1  Idii 

hromid  ]);iper  for,  sd'.l 

of  prostatii-  calculi.   K  it,.", 

of    extra-uterine     prejinancv. 

details  of  soft  parts,   110! 

of        pulmonary        K  n  : 

Id!  ',7 

exposure  for.  s]  _' 

L'land.-,    loos 

of   extremities,    hroniid    paper 

.-how  iiiL's  kin  marking-,  1  KM 

tuberculosis,  1001.    S.  -    uls  , 

lor.  Mill 

of  head,  .si  t,  liOL' 

I'lilniniiiir:/  /"'"  '-'   ;/...-     . 

exposure-  for.  sll> 

exposure  for.  s  1  L> 

of  p.Mipneumothorax,    1  (  1  1  o 

lower,    Kills 

of  heart   in  mot  ion,  sill' 

of  r;e  ills,    Kls'.l 

upper,  lost; 

normal,    appcaranec,     1dd.~> 

of  ranm-  of  lower   'aw    Cil". 

of  eye  after  iniurv  from   for- 

ohlio.iie. topography,  loo:; 

of  renal  calculi.  104s.    S, 

eign  ho,  lv,  '.I].".  ' 

traii.-po-ition,   1007 

1       --,-'.. 

of  eyeball  perforation,  !U."i 

ol   hepatic  ab  .   1021 

oi     ret  ri  iphar;  ii(.'i  al     abscess, 

of  fats  in  stomach.    1()L".I 

of   hip-joint.    Kills.      Sec   also 

!  I'l.'i 

of  feet,  hromid  paper  for,  sou 

IHll-johlt. 

of    rihs,    10IIL' 

exposure  fo:  .  xlL> 

of  hour-Ma.—  -tomach.    !(«() 

cervical,  (is!  I 

of  fern  if,  neck  of,   Idt'.s 

of  humerus.    Kiss 

of  rotary  dislocation  of  atlas, 

of  fetus  in   liter.,,    10ii7 

of  iie.im.   KlL'H 

'.I'M 

of     til,  ula.      107.').         See     also 

of  infant  stomach,   !0_".' 

of  sarcoma  of  hone,   1  1  o" 

/' 

i  if  inferior  maxilla:".  .  !lli"> 

ot      -eai  ihoid      fracture,      i;n- 

,  •    •  njrers,    IdlM 

of  int.-t  inal  adhesions,   lo_>>; 

1.    110(1 

of  first   molar,  '.«:> 

rcci;mhc:it     po.-iti'  i      in, 

nl  -•  i    inal  ve-icles.   KM,-, 

of  fish,   1  IL'J.   ll-'s 

lOL'H 

nl  septum  nasi,  !-s7 

of  flat-foot.   IOSD 

of   inte-tines,    IOL'1.      See   also 

of  shoulder,    10XC, 

of  tluii     in  sphenoid  cell-,  (1x7 

/,e'.,  ,','„.,.. 

di-!ocation,   1  ld_' 

ot  food  passing  through  stom- 

of mi  rathoradi    tumors,   Id]  ) 

eoI1Lnnital.    10!'.-) 

ach.   IdL'S 

of  jejunum,  lo_''l 

exp  .sure  for.  si  _' 

c.f  ;,  ,i  it,   KIS'I 

of  kidne\  ,  KM'i 

of   splienoid   i-e!!-.   osii% 

Illli  iroscopi          ex        i       tioi 

results,    ;;  "  '  ' 

of  .t,ii   :'  cai   ;'.   1017 

damn  r.    i-  i'..   107'J 

of  km    ,107^ 

ill    -:-  -  dli  -sh  iji     :    -  -  ,ph  iceal 

of  fureai  m,    Ids'l 

;  nt.  rop  ,..-•  rior,   107o 

dilai  ninn.  ''"! 

of   foreign    h'  nii  -s    in    .•-.  ipha- 

e\p  -lire  for.   s  1  2 

1.1    .pin.-,     looi.    loo:;.    KUd. 

i-'Us.  !'!l  1  .  ',i''_' 

of    knei  -cap.     1071.       See    also 

Si  .     also   >;- 

in  eye,  '.nix 

/>:>>'  '!.;.                                                                    o!    ste  losis   of   CsophafTllS   !)!)!, 

in  intestines.  lo_'s 

oi  kno  'k-knei..  K  17".                                  '.''•.", 

in  '.  i  ;  1  1  •_'  .   1  o  1  ."• 

.  -ioi  -.    •'  1.1 

o:   -t.  rne.m.  KHiJ 

in    :  i    'k.  !l'.i] 

•     '  '  i7."i 

-      '    •    •     h.    lO'Jl,    10!!.      See 

in  p   Ivic    iriraiis,   lOCni 

-             • 

iii  s  t  o  n  i  a  c  h  ,   K  '  J  s 

,...••,•         •   •             -_         ]    00  V 

o  f    s  u  i                     ...     -  i  n  u  -  , 

of      fra  'Hire,      Colics',       los'i, 

r    ,    [,    ..',,    '  I.,  ! 

Os  ]       See  aUii  .1  /••'     .".-'.-.  i- 

lO'.'ll 

ja-A  ,  )    .-it  ion  of  'iiln    ;;:.  '  !^.->                                '   ,  •>•'. 

technie,  iOiin 

mi  ,l:i  r-.  '.'Ml                                              of  su]»  mum.  rar  •  t"  ,ne-,  K  i"'i 

ur,  en-tick,   Id'.".' 

o1   lui    har  v  rt.  line,   K'i',7                      oi    -\  mi,hy-i-   pt;l  i-.    loii'l 

•    1    ilnm.   1070 

•:•-.•'•''.    loo_-       Se,         -                    '    •     •       !   fracture,    Ids  1.    Ills.-, 

i,:'    anteri.ir    sup   rin        pim 

/                                                                    ol   lar-us.    K's:; 

.   1071 

•     :    :       '  '                 l!ld-,        pUl-                   of    teeth.    •'-- 

,  •      ..  .  .    .,   HI'.... 

.         H  ills                                                      •           ...            •  ,  •' 

ertel  .".e.    '.I'.ll 

..-.'.'  1  '  .  ,                                      l]             .'.•->..'     - 

ol   davi.-le.   IMS 

f  !       .         ,  '"s.  IM  r,                               .  :   ri  :  •.-:..   lo;j 

INDKX 


•     '     :  ".;losis, 
pulmonar\  .    litnl.     S,  c  also 

of  tun    irs.  intrathoracic,  1(110 

-       . :  _• .    I  o  1 1 . 
of  in     k,  !".'.". 
ol   piti:itar\    b..d\  .  "17 
of  s]  ,  '.'xti 

cil  ' '.'  bin  ited  i..  Hi.  -,  "->  1 

uf  1     ph    id  s]  in.  .    ln!7 

ol   u'liia.    HIVI 

-.      til.    "'.7.    "ex 

oi  up].er  bicuspids,  v:;.' 

-.  "'..1 

r-,  '.'.;_>.  'i:;:; 
i  ter.   ln.-|| 

ol   u  ret  i  ra!     a!      Ii.   10.VI,   In.,.-) 
ul  urinal  .     lii.    lolx.     See 


-    :    -',    lllx'.l 
••  •    til  re.    KI'.I'.I 

.  .    phi    .     •'  '7.  St'.ix 
.-..  ••  M.  ,-ure  in.  xii' 

•    .   lili.l 

injections  into    joints 
;  •  •  .:•.-,   1071 
.        .    .     vl|l, 

peic  trai      n  oi    lay   and,   -.;.•,, 


Kadioi:raph\  .    \'acuum    in    tube 

•  •  utricles  of  brain   in.  '.Mil 
\\ith    hii.'ii   tubes.   x:;r,.   s)C, 
u  ith   low    tubes,   sijii.   xlu 
with  siimlc  Hash,  -~,,_> 
impulse,   711  _ 


Radiology,      determination      of 

anatomic  a<_'e  b\  .    1  ll".i 
Radiometer.-     for'  r-ra\      work. 

1  l.il',   1  I.".:* 
Hampson,   11. Vx 
Sabouraud  and  Xoire's,  11.1s, 

llx] 

Schwartz's,  11. Hi 
Ti  .iisi  ;.  's,      in      frontal      sinus 

fluoroscopv  .  '.i7x 
Walter's.  M:'l 
Hadiometric     tints,      Bc.rdierV 

1  lol. 

Hadiophotometric     m.-tho.l     ol 

Hadioiiuaiit  itomi  tcr,  1  1"  1 
Radiosclerometer,   1  Hit 

:    •    :    .  •.  -.':,.'   pcnetrat  :<  n   < .; 

endodiascope  for._771 

\-entl'i!    tube-    ill,     ,  XII 


i-adio-activitv  .   ll'l'i 
ba-ed   on   can:n:a  rays. 
1 1'  1 1  i 

•    '-*s 
iler-ompo-ition   oi    tatty   acids 

i  •  .    !  IT,.) 

.  !    Ic'.cithin  1"  .    IJ.Vi 
di-co'  er\    of.    li'pl 

lli-illteet'io!      .    '.     i.'i.: 
' 

•    •   .  I  I'd--. 

II-.  1 1'ti.-) 


Radium  in  earth,  ">_',  ll'lii 
in  pitchblende,   11' lit 
in  solution.    1 !'.".( I,    1  _'">_' 

apparatus  for.    1 1'.'iU 
induced    radio-activity    from, 

influence  of  thickness  of  layer 

internally,  dosaire,   l_'ii.> 

iuiii/ation  b\  ,   ll'l  1 

measurement  l,\  Sabouraud 
and  Noire  pastille-  of  ba- 
rium platinocvanid.  l_')x 

metallic,  produced  b\  distil- 
lation, li'ln 

ointment,   li'iiii 

oriLMn  of,   li'ls 

produce. 1  from  cariiutite,  ll'll* 

production  of  helium  b\  .  1 .'.",  I 

properties  of,   !_'  in 

puncture  for  carcinoma,   1  l'7'i 

].ur...       effective       emanation 

radial  i.  .n  :n  ,m,   !  _'  1 1 

pigmentation  by.    l_'lil 
railio-activiti,   of.   li'S'.i 
ra\  s,  ab.-orption  of,   ll'."i:i 

b\   skin,   li'iii' 
alpha,    ll'll'.    \'2\'.\ 
ajiparatu-  for.    ll'i'.ii 
api)licati..n,  li':>x 
bactericidal  effects,   li'.'S 
ben.  :     .al       .  ::'.  cts,        l.'.Vl, 

ll'lil) 

beta.    !.'ll.    ll'll' 
ehemic  eiTects,    l_>.-)5 
decomposition     of     -odium 

iodid   l>>  .    ll'.V, 
derinatitis  from.   1 1'.'.x 
divided    applica'ion-,     1  _'.",x 
dosaire,      I  I'll.-,.       S,,-     also 
lh 

'    on  animal's'.' 'll'iTll'" 
on   (leveloiimeiit,    1  I'l'i.' 

.    ll'C.l 

on  growth,  ll'iil' 
on  heart,   lL'7-~ 


eN]iosure    .  .1     ni  il'lnal     -a  hue 

•     •    •    .    ll'f,7,   U77 
camn.a.    ll'll.   ll'll' 
irl  is.-     '   . 
1 1'ii  1 

.   ll'.V) 

in   acne.    I  i'7H 

:  ii  i  ia.    !  _',  I' 
IP  ait  hriti-,    i  l1  Jl 


IXDKX 


in  nervous  diseases,   12,  s 
in  neuralgia,   12t>-~> 

facial,    !27s 
in  nevi,   127(1 
in  papiiloma,   1271 
in  pruriK",   l-ii'.i 
in  ]>nirit  us  vulva',    127 
in  psoriasis,   127n 
in  radiodermatitis,  12i>',) 
in   rodent   ulcer,   1_'71 
in  sarcoma,   1271 
in  7-cnilc  \varts,   127  1 
in  skin  cancer.   1271 

diseases,   iL'd'.i 
in   -mall   cpit  liclioma,    127  1 
in  sycosis,    12711 
in  trachoma,  ll'til,  !_'77 
in      triircmiual       ncuraljiia, 

.")Ur.,   1  l!t:5 

in  tumor  of  orbit.   l_'7."i 
in  urcthral  diseases,   Ulio 
in    uterine  diseases.    !L'ti5 

iihruids,   lL'77,   1L)7^ 
in  vernal  catarrh,   1 277 
in  verruca.    11s,   l-'li'J 
in  warts,    1  Is,   iL'li'.l 


ays,     caluritie,     isolation     by 

i|iiartx  Senses,  till.") 
magnet  i--,  (-,,-,() 
mau'ic-tocathodii',  li.'iO 


ld(i 

12H1 

radiography  by,    12">ti 
resistance   of   seieniun 

and.   12,-).") 

rhinitis  from.   12.".s  for     hiL'h-fre(|Uency     current, 

secondary,   1  2o  1  Flfminjr,  .",:;'.  I 

separation       by       inatriietie  for  t  ripha-e  current.-,    10.") 


stnmir  application,    1  2.",s 
theory  of,   12.')7 
treatment   !,y,    |2f,:!,    12(i!l 

(.;  -olut  ion  of,   !2or, 
standard.   iiit.>rnationul,    12tti 
-uliMinitc-  for.    127s 


use   of   flunrr.srorH!   daiisrer- 

ou-  in,    in' t 
Iti-iiiiai'       seb'-rcetifyim;      jr-r;iy 

Hc-iiioiis  cli-ct  rieity,   1!) 
student.".-,  2MI,  2:',2 


tiliinu'  bol>i,in  to.  _'20 
for  GaiiTe's  transformer,   74-1, 
7  (.", 

in    i.'ah-anoineter    and    shunt, 
Iso 

in   voltaic  cell,  ,s.",,  si; 
ind  ictivi  .  :<}.   "iH 

:•:-•.;::  •  ,c  in   of  circuit .   mea.-ur- 


1322 


•    •  •  .   .•      Io-t   by,  -..Mo 

:     -       •    •    :         -'  .'  inir.    17^ 
•         :•••:•.-•      .-.  :.   _'Ji 
;    -•  :•  _•      : 

•  u      :i.  _'_'•* 
unit  «•,   171.   17.'.  _'l'.i 
•  -.-•     :.    •  -.    If,  • 


K.  tii.  L    .-tT.-t    of    i 

l_'f._' 

• 

[,••'!:     :or,   H7 
H.  •  .....-:•••_•..•      b-ei  --.    r  i  li- 


T      '-.'•  '<  '     •iinir,  fiOO 
iirim  .  f,»0 

;.  •  rr  .:  •,     -.a;,,  .r   ii^'it    l".  ir.   tiVl 


r-alnpheii  for,  oiil 
tripha.-e  eell-bath-  fur,   1  IN 
ti;l" •:•  •  il;ir,  /--ray   f,  •'.'.    1 1VI 
x-ray  for.  lilKI,  tiOl,  1  iv.t,  1  1'Hi 
EUii'Uin  H oil  1     :irl  '.:•.'   -,        •     ,rin 

inntophuroi-  ii,.    1 1  i 
iliatin-nn      :  ii .  7'i 
fariulir'  current   [i  ,r,    iL''i 


H()s 

faradic  current  in  o'-ular  par- 
.  171 

f,  ;^ii 

Hibbon   inter]   iptrr,    11- 

••  .    ,.-tat,   -"I".  202 
Hib.Mit    and    Marie's    table    lor 
.  sltj 

Kill-,    cervical,    radiography   of, 


traphy  in,   1  !  I.1 

•       •  • 

hi   irt,   ion-, 


'I'.  ';--.V    inetliod    of   dorago, 

1  I'.l 

voltajif  for,  7.V> 
liiniueii-ray,  (',.",( i.  r,:i_' 
ab.-orptio'n  "f.  li'.i.") 

\>\    air,  f,'.i.^ 


n  i  n  :  •  r.f,  71  I 
after   nerve    re-ectiun    for   tic 

alterr-ttiiiL'       ci;rreiit       trans- 

toimer  for.    Ififi-  Uis 
nnirnint     of,     tor     treatment, 

1  17,2 

renif-tfi    for,  ^."iO 
ami  ili.-rh:.i-L'e  rays,  71.-, 
am  n  '/:     from,    in    1>  ukcniia, 

anode  of,  u-e  of  alone,  7f>0 

•    fif,  ()!•!),  7(10,  7.7J 

•     n,  7'io 
n],parat'.-.  injury  To.  in  radi- 


radioL'r:tp}i\-  in.  '.'!'.»  ;iproii-  proo!   atrain-t,  M)2 

;  tube     for,  bactericidal  valm  .   1  l^'l 

ol.V  baliin,--  from,    1  \:>,:>,    1  lo- 

m,  7H1 


pi.!-  pha-e     cm  rent-     ir  . 
7    !  l-'7 

.,    ,  7  :l  t.  ::.-'    '        •.          ,-ed     ma.-net, 

•    -  -      .  7   : 


:   a-  unipolar.   ,  ,  •', 

:.   MO 
II-..;  l.r.-akiiiu  :.  .:> 

Mrickm  i4-  -land  tor,   M7 

•    .        ,  ted  !,    71  I'.l 

•    •  •    ill-  oi,  TIHI 

-tn     :  .    ;:  .   7"  ; 
chan   of,  70-' 


IXDKX 


RontRf-n-ray,     bipolar,     electric 

IlontKf-n-ray,  |hi[io!ar,    punctur- 

1;   int  irr-n-ray,    hipol  tr,    v.  it!,    in- 

generator.-     for    exciting, 

iiiL'  "i,  7"i-.i 

i      .    r-urient.  70(1 

71.", 

I'upin'.-,  77:1 

with   o-mo-rcirulator,  701  1 

i-ndodiascopic,  771 

(jueen   self-rejjiilal  IIIL',   7i'>:i, 

without    ant  icnthode,   77_' 

excitinL'   nf,   d'.l'.l,    71"> 

7(11 

i\  ithoul  internal  elect  rudi-s, 

hv      indl|ctioll-coll      oper- 

n-lu-:iiL'   to    tniii.-mit     cur- 

77:; 

ated  by  cliM-trir- 

rent.  7"i7 

w   •  •      it   re;        lor, 

liirht    '   current, 

re-rn!.i:ion    of,    for    nnliotr- 

.vi-riiit',   -«Hi 

71!' 

raph.v,  7n  i 

rai.-iiiL'  vacuum  ui    xnr. 

l).v  naivanif    cells 

rc-i-t.'ini'c     in,     tor     radioL'- 

hi-i;h,l,:itc     oi     nuinin     with, 

717 

rap!iy._x;U 

!_':;.", 

hy   r.oyden  jars,  717 

lirotii!               -    .   1  i:;i 

h\-    static'    machine,    (ill'.). 

"'I'iiTaril'.^O.-) 

hum.-,    1  1  ]_'.     See  :!1-..   /,'',    i- 

71.').      Sec     a  so     &„/,;• 

secondary      current      from, 

'/•  n-fii'i  -''  rni'iti't.    . 

Hindi  in'  for  .r-nnj  ii'orl;. 

volume   of,    s."i'.l 

Caldwell  interrupter  for,  7  JO, 

hy  jr-ray  coil,  li'.i'.i' 

rays  from.  7dl.     Sec  id.-o 

7_'_' 

exhau.-tion  nf,  Vlx 

'Sn-ntnlnri/  ni'/x. 

interruption-  oi.  v.'.j 

extra   rays  from,  7','1.      Sec 

si-lf-n-milatiiiK,  7i)l 

wit!,  alumimin     c,  ...   s.-,l 

also  Si-raii'liiry  riiy*. 

(v)uecn,  7i','.',.  7H! 

cancer  from,   ,0,  ,   11  )i; 

r>0-i-f>nt  inn-tor,  7.">s,  7o'.» 

Thompson's,  7iit 

cathode   ray  and,   liol) 

fluorescence  of,  710 

Dimple  form,  li'.Hl 

changes    in    torm    of   stomach 

for  mouth.  771 

sinjjlc-focus,   Tou.-c\'-,   7H7 

:    i   hy,    IHL'1 

for  radioirranhv,  7"iX  7iil_' 

small,  7.-.s 

in      niotiiit\-      o: 

rcfiulatl  !',  70d  ' 

soft,  7o:; 

found  hy,   IOLM 

Tousey's,  7f,7.  771 

.-l)ark-i_':ip-  for,    ,01,    ,  M'. 

icterist  ic      honii  iL'i-iie,  ,  :-, 

for  treatment,   1  1.~>1 

sparkiiiL',  leimth  of,   7:  11 

i  i1  ii  i 

Friedlander's  water-cooled, 

seconilan-,   voltaRc  of, 

produced         hy         heavier 

7(>:-l,  7o  [ 

7:;i 

metal-,  (".'.til  ' 

pas  in,  v'.'.i 

stand  for,  M7 

C'liarijonneaii's      trati-f'  >i  mer 

helium,  7f,."i 

^t:^r  ic  ncu'lii  ic  for  •  -xcit  iiiir. 

for,  71'i 

"in--  i  if,  77l_' 

71.',.     See  al.-o  St.,/;,-  mn- 

chi  mic  elf,    'ts  nf.    1  l.l'l 

Gu'iilciz's.  77:-! 

rfii/ii    for  x-ray  TO/-/,-. 

mil,   l.'l.  7:>n,  7:11 

Gnndclach,     heavv    anode, 

Stern's  unipolar,  77:! 

choke,    137,    l:;s 

7(M) 

Morair.-ha'tery  and   in  l".c- 

effei'ts  of  •>•.  orkin"  n  >ar   :)'  i7 

liirht  anode,  7di> 

tion-coil  for  '-xcitinst,  7  IN 

for  hiL'h-frequencv        n    n;, 

water-cooled,  7f,:i 

tariret  ot,  li'.i'i.  70!) 

:,  i.; 

liard.  70M,  s:-i  1 

tcchnic  of  u-iiiL'.  I'.'i'i 

Pill  .-i     safety-tnhc     -.  hit, 

heavy  anode,  7o(),  7i',l 

Tcslu's  unipolar,  77:', 

7i)o 

liiirh.  7n:i,  7(H 

'rhompson'-        .~e!f-reL;nlat- 

self-induction     in     primary 

results  from,  Md 

imr,'7i;  1 

of,    Kill,   l:-!7 

hijjh-fn-eiueney,  7dd 

Ton-";.  '-.   l-'lx 

xcit.il     hy,    opt-ra- 

lllti-l  tiat  iiiL'          M'Cotidary 

hifocal,  for  radiography, 

.    !  i    11 

ciirri-nt,  7.'-i."i 

771) 

winding  or,  ].-,! 

hydrogen  in,  7dO 

dosaiie  with,  iL'l'.i 

conductin,;  cord-.  7:io 

..       ;       ,            ~']t' 

1  !  I  ipcl't  1  'i  '!  1,  il  1  -    ill.    t  Ol  t 

induction-coil  and  storage- 

1  '  >r    j  i  v  iiT  it  L;L     Mlvffjlun.-, 
Dili 

t  eel-    lor,    (  -  ,o 

battery  for  e\i-i-inir, 

:  ir  "  nlii  ijtraphy,  7»i7 

1  •  •  t  T  .  7  !  •  ', 

7lN 

trained.  ^  to 

:      -     .      '    tin    n          .  .   i'1'  ! 

operated     hy     plcctric- 

tunir.-t  'ii  target,  7ii_' 

cumiil  :-r  e  cffi  et.    !  l:,l.    ]  1  |.: 

liirht  rurrent   for  cx- 

type  of,  7JS 

curatn-e  value  ot",   1  loll 

citinc,  71!) 

unipolar,  77:1.  1  I'd 

cure  in  cancer  <  if  lip,   li'l'i 

injury  to,  in  radiosiraph,  MM 

vacuum    of,    loweritiL:    7'i'i. 

;n    tit.    voltut'e    ,  :.    tin     -    '- 

inver-"  ciirren!   in,  7'  ;''i.  7d7 

7i)l  .  ^  17,  S:IN  M'l 

,     1,  7:> 

dischanre  of,  77H 

iiM"i-uriiiLr.  N:>:;.  ^:i  1.  so.'i, 

dare'i  '    '.:.    u-e  o  ,   7'  ''  ' 

suppri'sMoti,  Mil 

M:: 

to  liand^  from,  70ti 

hi  IX-.  7AS 

rmli  iifruph\-  an  1.  s:i) 

il:i;._'e!on-     in     production     of 

leaker,  li  ''i 

rai-inir.  7lU,  7i',_',   «:',<\ 

-teri'it.'  .   1  1  17,   !  _':> 

:    •      lion,  7ii'< 
l.i"  id  ']   iar-  to  exciie    717 

wi  1  1  u  11  1  1  n  -sii  i     •  .  ~>  ;  , 

'•    '  •  '  i  •  :  .  .  •     71*) 

.      tl,  from.   HID 

line  IM  di  inarcat  ;•  m  in,  7'in. 

-•     :  -.    1  l-'ii. 

^:  i^ 

rai-.-,  s:iii 

di  :.-,;;.    and.  I'.'.i.'i,  li'.ij 

locaiizini;,  77_' 

valves  of,  71  17 

.,   i  ].;_' 

!.,«-,  7n;; 

\  iiricl  ;.  -.  ti'.>'.l 

11        '      111!       -cri'i   I!       t    '       P'.    - 

•     •       •  .  •»  1  1  '. 

-,-,•• 

-  ,  •  •    7lls> 

n.   Mti 

-.71! 

-    '.  i  i  ;  ; 

Maclil,  i;       hiL'h-tre.iiieUcy, 

vi-ntril  tnli.  -  i::.  7v 

:    1.  n-i  •    tin    ir\    ,.:',    UM7, 

,  liil 

-eric-    \\  itli      7x'l 

1  •"  s 

water-cooled,  7t,:; 

Nlllard's        ..MHO  ••      ,     •    • 

decrees  of.   11  i:; 

iiieditiin.  7IM 

for,  7ol,  vsii 

tro!  .   radii  'sirapli'  .   xi  - 

Morton,      in      ,-:  iti  fliojna, 

with         ,  --   • 

:      _     -    -      ;.•'•."•_ 

1  1  .".  1 

~  '  i  '  > 

:-     .                     [jni 

Miiller's   11  11 

Volt-'   '!.::.   7f'.l 

-en-.  •  ii    •  -    prevent, 

water-eo,,led.  7>;:; 

Wat  C--CI  ,,  ile,     ,     ,  l'i  ! 

,"•  » 

i  i]  ,  .rat  ii  ii       .-.   li  •'  i 

u  at  i  !••:•.'•:•••.     ' 

..  li  c; 

i,~,-i!!o.-.c..pe  in   si  •!.-  •.  i    . 

••  '  .  77J 

o  :  hand-.   11!:: 

-•'       r,-i;!-tior  lor,  7f,l 

-  ,  ( 

•      i     •  -•    :>.  1  1  (: 

;••-.•:'      •  .  ,   7  '  '  •*  ,    1  I  !  7 

it,    1  1  !J 
•    -.  itr,..   i  i  !_' 

• .  nil 

i   I.  !i:ii) 

"i rnea,    I  |:!'.i 

on  ei    -•  i!lii  ,    '•  n-.    1  1M' 

oi    erytli'ro      ••  -,    1  1  !_' 
on  e.\'i  .  1  i:-Js 
•  'i 


M.;, 
•  •          i  i:;t;,     n:-;7 

.  i  i.i.i 

1  i:1:-; 

:     •  -   -;,  -tern.    1  I  H) 

,,[,tic    :..  :     e.    1  l:;o 
!  1        .''.'- 


in   indurated   cleat  rice:-,  <',1_'7 
1  iou.-  di.-ea>c-.  l_':-;s 

in  int.  reostal  neuialL'ia,  .".(i7 

in  iti  liinK,   I  I7s 
n    ii  Hit   tubcrculu.-is,   US'.) 
it.  fiL'7,  117i, 

in  kidney  tuhi  reulo.Ms,   1  Is'. 

in   lar\  nueal  cancel,  r.d'.l 
tuliereuloMs,  <',ds.  r.d't 

in  lat.  ral  selerosi.-,  oil 


:-.-.:•     an.]     relati 

L'a-t,'ic  tindins.!.-  with,  10L':: 

i:iireeti!;ed    t  ran.-fonner   as, 
7  i:; 

hand  for  totinir  rjualitv  ,  Ml 

in,  71.; 
In  '•  roi_'eneoii>,  alj-orpt  ion    1,\ 

utei  ia],-,  i'i'.'7 
iciic;    coil  ior,  "J'e-la. 
7fJ 
|,i-t,  ],,Lric  effects  of,    11  U 


•  :-.  tuliei  .iilar.   1  Isii 
rea I  a .    1  1  7r, 

...        ..i  KIS 

ii      irthriti-  "d,  '•.:::.  MI-.    !  I'.id 
.    1  17s 


1  Is.',,    1  is,;.   ]  ]x7 
in  lyuiplu^arcoina,  1  I'.is,  ll'IW 

in  maiiunaiit  di-r  a.-e.    1  lijo 

.   !  l'.i:J  ' 

in  moles,    1  17s 
in    ii:\e,,M.-    luniroides,     lls:{, 

I.'::.; 

in   neu-al-ia.  .Vi3 
facial.  1  I'rj 
iriti.-,  '>'.<'.', 

.   Us,   i  17s 
in  old  -i, ram-.   1  I'O 
in  nfi-liiti-.  ."is:; 

.  iti.-.  tul.i  n  iilar,  ll'.Ki 
in  o-t.-nmaiaeia.    lj:;s 
in      periadeniti.-.      t  i:l/ereu'ar, 

in       ],en!i,:;eal       tuliercu!o.-is, 
1  iss 

;  iss 

i:.   pi  rnieioa-  anemia,   1  l''s 

.    ,  1  I'.t'.l 

in   p    "-v.  .!.•    -::;m-.    I  17s 

in  pn  in;  c,,-i-,    !_':;;{ 

in        pro-1  a  '  ie        I    .  ;  .1  :  t  n  ,]  ih\  . 

i  r.-i.  1 1!'.-. 

i     pi     -1        •  .  -.    !  !'<:.    1  p..:, 
1 1 1  p  1 1 ;  r  i  t  u .- .   i  1  7  v. 


I .  .-,  1 1 1 

. 

in  ih,  uinati    m.  ill  Ml.  Hill,   1  I'.' 
•     her'        ir.   1  I'.'ll 

ei,,!          ,117(1 

11     i;      :         '..    '  a-,  .   oil. 


INDF.X 


in  minor  i. 
in   ul. -cr.-.    1  [7!l 
rodent,    I-'KI 
ii:  \  crrujra.   I  1  X   117s 
in   warts,    I  Is.    1  !7s 
in    \:  1 1 1 1 1 1 1 1 1 1 1  ;i    :  1 1 1 1 ! !  i  1 1 1 1  •  \ .    1 1  L".  i 
induct  ion-coil      and      -r"l:  •••• 
battery     for     cxcitinu 

operate.]      by      electric 

lii'lit  cnvrciit  for,  7  !'. 
In-  jtMlvaiiic'  i-i-ll>,  717 

sci-oii(lar\-  curn-iit  of,  ,  .'i, 
iiillurin-r  of,   ilurinir   dr-vi'lop 


Hontnen-ray,   lenkotovin     from,     j     liontifti-ni    .   re-i-tano-  t' 

IJIi:;       '  rheo-ta!     lor.    s.',  ] 

I.eyden  iars  for,  717 
I.,-'-  nt  r-'iiht   from.    1  l:i'i 


on,  '.Mill 

injection      of      photodynamic 
substances  before  exposure,     | 
!L'::s 

injiin  ,    \rnei  ican   radiologist.-     I 


mtrn.-ity  nt.  s  |s 

MIT-L'''!^!^'-    Mctinoinctcr    to 

linr  i  if  (in-atcst,  s  Is 

rent   and.  stll_ 
intcrniplcf,    \:',7,   i  _'(),  s.'c> 

Hcakcr,  7L'D.  7i':; 
C.-dd\vi'!l,  7L'0.  7l'L'.  s.'ii'.  s.">  l 
uilh   aliiininu!!!    i-i-ll,   s.M 
C'a'-pi-nticr'.-,  7_'s 
character,  s.'i_' 
ci  in  inutati  ir  i  ypc,  7:17 
C'ontn  'Moulin;  7Js 
Drault's,  s:..-, 

•  LC,    iniTcury,    I'ari' 


r.    r'!s 

- 

.-..::.•      -'  '_• 


liiciu  .  7!  ! 
metal,  71  I 

diaphrau'tn,  7'M 
mild  applications,  phy-in- 

imrir  .  tTi-i-t.-,   1  i:;n 

1  1  I'.i 

ill-.'  ••urri'iit,  7-n'i 

7 -Hi 
direct  current,  ")() 


nephritis  from,   1111 

1  i:;s 

:  -cul'ir  t  ronhic  ac'  ii  m 


li  ir     >a.-r.  '\I-YK  bra!     art  liri- 

ti>.   in;  i 

I'm-  n<-  dnti'ouri'iix,    ln;i 
line   -nlutinn-   inn!   -kin,   cur- 
rents : :     •  ,,  L'ti'.i 
lectt  i'-  rnniluetivity  of,  :;'.'7 

•      •      :.    • 

rcrvica!  s\  mi. at!  etie,  M  I'1 
Inphen   in   rheuinatisin,  r.nl 


-        •    •        -  •   •  •.  f.,r.  1 1 

~f,  ••: 


.  :  b<.ne,  radionraphy  of,   1  lor, 

..i   ;;.•,>,.     •--:        .:..    !_::;.! 
. 'p.  ;at  inn   1.  .r,    i  -'Ml 
'  •  •      !_':;_' 

in.    1L'71 

'.11  lili,    1  I'M] 
:      '          '  •  '  '          ' .     '   '  .    !  -'•'••'• 
•alp.   :  :-.  'i.-  nf,  j-ra\    in.    1171 
'•  .•]       tnnia         -,      ;'ra    I   ire      oi 

-,  !id,    f!     ill nji\    tn 

•  n  ntiate,  '.(il 

<  .sr-ntiv     tn     dilVeri  lit  iate, 


Sciatic   in  urit  i-   i,->ti'il   by  Matii' 
\v:n  c   ,  urrcnt,  ..il'.i 

hijxihir  liritli  fur,   "ills 
li!i:i  -iiLriit   hath-  in,  tN7 
i-utniihi.n  >:.>  I'nr.  .Ml'.',  ."10 
clirnnic,  .Ml^ 

I'.dM-ilkit'-.    trciitlnciit,    .Ml'.  I 
I'lrrtl        -       for,    507,   .".II1.  1 
nr.iu-ni!  liica.-uri's,    "illl 
-•  •  •       .  '.  i  i  :  :  ••.:•     :    •  .   ."()!) 
•  'tit  H.  !;..i,-   cul  rent    fur,   .Mis 

iliatli.  nny   !<.r,  i',:;7 
i'!cctric-it\    for,  .Mil,  :>(it> 

•  ,  M  i7 
laradii'  current  fur,  .Mis 

•    r  •  i    .:•.:.'    '     -..Mil 
)iitr)i-!rci|iicliry     curn-nt     f..r, 


atlis  in,    I  !:; 

!!l.ii]c..il    ci;lT(-nt    !'.  if,    .Ml'.  I 

I!   :,--:.-.•    I'nr,    ."ill! 

ni  r\  i  --t  n  t.'hiiic  lor,  .">IO 

•  inn  fnr,  .".in 
.'|..u'ii.,-i-.  .IK) 


, 

cii  •   '.  Icrina   circr,ii!.-cri].t  a.  L'al- 

iirri-ntr-  for,  t_''i 
tra!\  anic  current  i'nr.  -IJii 
static  i  iri-1  1  i<-:!  y  :•  .1  .  !  _'7 
j--r:i\  in,  !  Is] 

y.-V-'in,    17.-)" 

I'li'nrin  ca':i]ilinroir.  fnr,    1O."> 
latcl      ,  i-li     .....  .".11 

iniiltil.lc,    clci-lri-'-ity    :..:.    ."•!  ! 
i.-,    r:'dinfrra]ili\     in.    1017 
li-h-n  ark.-  nn   |il;itt^.   s;ij 
creens,    I'l.rium    platinncyanid, 

.-:   :•     work.    ll.V,' 
.  iar.    l'.U'-k\  .   fnr  am  -1  ::._' 
-i  i  .  .111  |ar\      ra\>     fmn      ti.— 

>UI    -.     .    l.'.icc    of,     sjx 


' 

' 
s_M 

7'.' I 


•    .;.        f-,i         i    , 
r-ray    expo-un^,   Tnn-rv  '>, 
HMt 

-P.  .  <i  uf,  '•  ~t  int'.  sot 

1 .1  "c.l        lirtu  c.  n       j.at  ii-nt 
If,   x-'~- 


tn]     .     :    .'      «nrk,    7:<1 

.  l.'ll 

.1;1- 

:     .     •.  :  n; 

•    •          linn-.       led  l.y  vnl- 

t-ii,  ci : •-.  1 1" 


INDEX 


Secondary  coil,  wire  in,  1  17 
current,   l.:i 

j--ray  I  ul»'  tor,  7:11 
amperage  iif.  I-,-' 
duration  of  Mow,  i:,7 
e.|ii:i!i/.irm  of,   !.",.> 


itod  in,  7:;_t 
strength,     mca-iinni.',     !•">:;, 

ir,7,  ios 

rays,  7!U 

ari-iiiLr   it.    tissues,    suppl'c— 

-ion    of,    filter    i-l  '- 

plate  lor,  ,V>0 

Cole'-  observations  on,  7'.i7 
derma,  7!M 


S,     retii  in   ciirrenl  -,  _'7o 
Secret.  ir\    di-t  iirbances  .  if  • 
;n-li,  electricity  for,    i:iO 
e    effect     of      ta'.ic 


protoplasmic,   1<;:,,  -Jlili 
rea  .finn  of,    till,    H',7 
.-••L"  .'-'it;1 !    distribution    of, 
K>7 

for,  .",!  ! 


iort-circ'iiit,  -HI 
(ire  from,  I'm; 
of  volatic  cell-,  no 

I  _,._!;  j 

rlisliii-atuin      of, 

I'adiotrrapiiy      of,       HIM", 
110:3 

radio-.-;, pl.y  ,,f,    (fl'.l.'i 
epiphy~eal    iniui       al    • 

raj/hy  of,   MMi.'i 
rluoios.'.up\   of,   III-M; 

'.    K'l'.Hi 

ob-cutv     dUea-i        f,     rad      r- 
rapli.s    in,   1  Hix 


Seed    .r-ray    plate  and   Ka.-tman 
(iup'.itizecl    .r  ray    film, 

tive  speed  of,  M  1 
relative    -p.-ed     of    other 

plat,  -    and    films    com-          Shove!      eleetrode      ;,  •       fiy.l 
pared  with,  s|  I  •       •   :, •  •  •  ,    :    - 

S,  i-Ii  ;.    ..•  :'.•;,    apparatu.-,  -o"  Sli  nil    eii    i;it.    |s7.  L'l  i. ; 

Selenium        cell        in'ellsitler        to      '  'n    eleet  rother;,pei;ti.    •,     -'' 

mea-ure      ^-ra\       d,  .>ai:e,  re- i-tanei       :•  .      L'a1 

]    1  00 

:  id    in     r:i  .-    ind,    IL'.V) 
S,    f-inductanee  in   prinnrv   coi 

api     ral   ,~.   s.">s  KI'.I 

-  li-iiidiii-tion  coil,   1.,:  -    :•    • 

troi;  .    !:;o,    |  ;u  o,i 

..........  .         .         ,.      . 

en-.    I  in 


.in-  iiiiL-  c,,rd.-,  7:,o 
ihiru.-  el,  .-I,],  ii.-,   ".t 
ilver  el,!,, rid  c,  !|,  MIJ,  !i:j 
meter,  L'4'.l 

ine  fralvanometi-t>,'l!u" 
of  :iwr!c  .   Mill,   I'.il 


I). 


!Mi!l.        s'ee     al.-o  '  /••'-''.•/ 
trail-illumination  of,  (-x! 

anti  r'opo-t  'lior,  '"'.'.',  !i70 
sujx-rior,     raili  .1:1  t| 

I'M.      See    !il.-  .    Ai  'rum, 


tor  chon  a.    111 

for  •  ,  OOo 

for  diab.'t'e-.    1  !_' 

for  hi     :  •:.-••-.•.    112 
ills.  '.I-' 

for  h.\-])ertension,    I  II 
;,  r  liicoinotor  ataxia,    1  1  1 
:    -    :.    rvtm-    di-ord,  rs,     ;  1  1 

n      •    -thenia,   111 
for  neuril  i-.  .")(« 
lor  p  iral;  -is,    I  l_' 
I'-ir  >einti:-:i,  o,  is 
fn  ,;:;  rot, -IP.    converter,   !"._' 
_•,  n.  ral    ij:'li  'at  i,  in.-    :.  T    .1- 

!,        t-    Ml.       Ul 

ind      iti  in-  f.  .r     1  (_' 

N1.:!!,     rliythmii'     variation, 

!ss 

i     therapy,      jamph-s    of, 

1 "_' 

11   i. :,'!,.    Mo 

•  :      Uaynaud's 

!  I .") 

!•-.. ,rie  bath-,   ft.', 
prii     i|          •  •.    Ill 

1  in 

•     -.117 
.tin 

•  •    pa  ral    -i-,    !  H 
'         in-ill    •:-,     1  III 

:  :  : 

' 


:.-i-  ,  f,  _.7l 

I'ele   -     t>l     111.     -'''' 


1  N  i  >  \:  X 


•    •  .    1  _' .  1  St  i  •  1          -         ' .  • .    1  ! . 

:._.    IJ'.J  -       .    :.   I'll  I 

ill    nl,    •         '  n        '      :          ml,          Sulr    Icatln-r    a-    -'Tern    f-.r    -oft 


• .  .>_'.  :;v, 
:   .  ..-; 
\\    -  -.    -       ;.,-,  .-  ,,,t-r      in, 

;'  i 
.-    '  _• '    ' .          ' .     - 1  a  I 

II.    1  IV, 


v,  :;  ',,  ..'.id 

- .  HIT,  711 

.'.-...-        •      of,  „':;:; 
(-1,-rTroly-i-  .,!',   li'l  \ 
),;,--;:•   -of  <•!.-.•!!       :•       - 

L'til 
Solio  pap,-,,   ,v; 

,.,    fnr.    SSI 
p!  illt~,    lll-llt'l  '.    ''  '.'I 

ti'l,    -t:'tii'     '•    • .  .    •       fro!    . 


!  !'•(•!  rode,   indin     t,  o, 
ii,  til  i 

n-'l    cm-;  .     '  i:      carn-cr, 
:,-, } 
in. lii      •.  'ill 


i]    • 


i-      atti-r     /-ra\ 
n-turn  ui".   1  t:>,\ 
])<•!  inatiizoa 

1  i:;::.   I  1:',  I 
outr-idi-  l«,ily,  z-r:i\   ami,  1  i:r 


i.l,  i-li-i-trii-it\-  lur,  -C-ili 
'.  •  ritn.-n  .-\  philit  it-a. 
ojrr:i]iliy  in.   Ill-' 
/-ru>    in,   IliKI 

if,    17."i 
i-aiial,   hulli  '    in,   T,  ilii  iri 

in,  KU7 

r'olun.n,   lati'Tal    '-1:1  val  iri 
.   1017 
I'(,ir-    di-,.:..',.    of,     radinir- 

raph;     ::..   KlUi 
radi.ipiaj>h\-  uf,  1  ni  1 1 ,  Ion.;. 

i  o  i » ; 

plirat'ii)  lor,   HHii 

I      U'l   ipll       il 

KU7 
i  -.  pl;nid.      radii itrraphx      - .: . 

1017 
ford,    ili.-i-a-..-    of.    i-I..i  i 

.  x     -    -      :     .,-.:;!! 

in-    ..t,    UN    in  :,    and, 
::l  1 
lati-iit  pi-i  ioi!  di,  :;.;u 

.    . 

•       •      ,          -lilt"      '•'..     '•':  1- 

inncrvati'd  liy,  tulilc,   ',<•  • 


INDKX 


po,,_;e   electrode-,    \.\ 

.M.  ,M  ic      elect  i  i.-ii  \  .       circulator-. 

Static  cleclricitv  from   -ound 

55 

and  in.-ulat.-d   handle,  .;x| 

functions  and.  72 

from  uind',  51 

>oni;\    platinum,  x:!7 

condensation   ot    -team    b\  , 

from   wood  splitting  51 

...I  ti-\\ood's          induct  ion-coil, 

5d 

p-neial      stimulation      ] 

ro- 

151 

counterirritant   ii-e.  50 

duced  by,  71 

principle     of     electrolytic     in- 

death from,  .".(id 

glandular  secretion-  and 

71 

terrupter-,  7211 

definition.    17 

irlow  discharge  of,  57 

.rains,  lumbar,  elect  ricit  \    for. 

discharges    of,    phy.-,ir.-,l    ef- 

heat   from  discharce  of. 

5s 

CM 

fect-,  55 

piodu.-i  ion   in  l.o.K    a 

nd. 

old,  r-rav  in,    1  I'M 

dosage,  70 

71 

.ra\    director,  (Id 

measuring,  17 

heatmvr   effects  of  dl.-ch.- 

re,'' 

electrode.-,    (id 

unit,  711 

of.  511 

indirect,   Tousc\  '-,  lid 

d-  namic      eleel  rieity      and, 

ll.\  pilot  ic   effects,    72 

H'lne;    catarrh,    elect  rol\  ->i  -    in, 

comparison,  2H,  7.x 

effect-,     :{()5 

i  n  elect  ric  eel,  5  1 
fish,  51 

>rintremcter,  7:!1 

electromagnetic,  57 

in  t:\-mnotus,  51 

aininc  solutions,  X72 

,  -\citomotor,  7:5 

in  nature-,  54 

ains  on  plates,  Xdl 

on  air,  57 

in  plant   life,  51 

and,    .r-ray,    Used    by    TOII-C\  , 

on  mii.-i-nlature,  71 

in   Kaia  torpedo,  51 

XI  )(  1 

on  .-kin,  220 

in  Siluriis  elcctricus,  51 

Clark's,  d2 

physiologic,   71 

in  torpedo,  5-1 

induced,  112.     See  also  >'.' 

lit, 

Fleming's,  d2 

thc-apcutie,    71 

utilurttl  fiirrrnt. 

condenser,  2:ili 

electrodes  foj-,  :<XO 

intestinal  secretion-  and 

75 

ar  nena'ivf  file.  Xdl 

fatigue  and.  71 

licht   from,  57 

arr's    table    of    muscle.-  inncr- 

for  a,-,,,-,  127 

magnetic  efTe,-t.-  of,  55,  ." 

7 

\  ated  b\-  -ninal  cord,    Kil 

for  anadilorh'  dna.   7-". 

measurement-  of.    fx.    !' 

alic  bath,   lid 

for     arterial     In  perten.-ion, 

mechanic  source-,  55 

electropositive,  K2 

71 

motor       stimulation       | 

.0- 

for  alopecia,   127 

In  pol.-n-ion,  7  1 

duced  by.  71 

tor  eczen  la  ,   <  -i 
for    habitual     constipation, 

t..r  a.-t  hma  ,    l:i  t 
for  atony,  7:! 

na  t  lira  I   source.-  of.  .  .  1 
nitric    acid    from    di-ch: 

,.,„ 

!•'!] 

for  cardiac  depre-.-ion,   72 

of,  57 

for  neurasthenia.  52:1 

for  circulatory  disorder.-.  71 

of  body,  L'tix 

with  obesity,  7:5 

for  diabet,-.-,  71,  507 

ozone  from  discharge  of 

57 

for  obesity,  7:? 

for  eczema.    127 

pathologic  effect.-.  M5H 

for  pruritu-.  7:-! 

for  frost-bit  i-.    127 

phv-ieal  effec-t.-  of,  55 

for  skin  disease,    127 

for  furuii'-ulosis,    127 

phy.-iolotric  eff,-cts  of,   7 

] 

breeze,  21 

for  jnmorrheal  rheumat  i-m, 

pulverisation   of   steam 

by. 

counterirritant  effect    from. 

77 

5d 

72 

for  Ic-art   disease,  71 

,iuantit\    of.   mea.-urinL'. 

17 

direct.  li.S 

for  hypochlorh.xdria.  75 

rate  of  trave    of,  2d 

effects,  :-;05 

for  impetigo.    127 

repul.-ion       of       eompon 

ent 

for  chorea,  5!d 

for    iii.-ont  incn'-e    of    urine. 

particle.-  of  bodv  by. 

>5 

for  contusions.  7:1 

7:;.  I2d 

,-edative  effect    of,   71,   7 

_ 

tor  ccchx  mo-.-.  7:; 

lot-  insomnia,  72 

se:isor\    stimulation    b-,  , 

71 

for  cry-ipcla-,   7o 

t,.r  k<-  oid     1  '7 

-ourcc-  of,  51 

for     habitual     con-t  ipa  1  ion. 

tor  lichen,    127 

-jiark.-,   application,   (HI. 

i.ii. 

t:i  1 

for   low   arterial   ten-i.ni.    ,  2 

value,  72 

for  infant  ile  cerebral  pal--.  , 

for      lupus     er\  thcmatode-. 

-landiim     of     hair     on 

-nd 

517 

127 

from,  21 

for  mild  muscular  pain-.  7:; 

tor  iiiorph.-a,    127 

stimulative  effect,-.  72 

for  ncurasfl  enia,  522 

for  ne  ira-thcnia.  521.   525 

t  lierapeut  ic   indie-it  ion- 

for    neura-t  icnic    insomnia. 

t  .  n*  oh.'-it  \-.  7M 

72 

52:-! 

for  ..xaluria.   71 

tissue  chanties  under.  71 

for  oxaluria.  71 

i.  ir     pelvic     disorder-     »  i'  h 

treatment  by,  5d,  Hu 

for  pruritu-   vulve,   7:i.    127 

Inperemia.   71 

accessory   apparatn-. 

1! 

for  sciatica,  51  )x 

tor_  pro-tan.-    In  p.-rtroph..  . 

electrodes  for.   lo 

for  -kin  diseases  of  neiirot  ic 

1  .eydrn  jars  in.   12 

origin.  7:1 

-or  pruritu-.    127 

position  of  patient.  1  1 

12 

for  suppura   inj;  wounds  7:> 

;.  H-  p-ona-i-,    1  2i 

universality    of.  51 

for  torticollis.  51d 

tor  radiodermatitis.    !  27 

u  ave  current.  ii:f.      >.-.    ; 

Is'  ' 

tor  u"ica.-idemia.  7  I 

for  -ciat  ica.  77.  50d 

Stu'i,-  inin   i-iirn  ><>. 

t.  ir  wr\    nee  ^,  5  1  d 

tor  sderoderma,    127 

.  lectrodcs,    C-; 

indirect  ,  lili,   H7 

for  -cxual  impotence,  72 

electroscope.    1211.    1215 

-park  an.  1.  fix 

for  -kin  di-.-a-.--,  7:',,    12i. 

ia-ad  breeze,    12 

•  hartr.  .    unit     of    d.-n-m     ,,t. 

for  -luiriri-h   w.nind-,    127 

induced  current,  ii:i,  (15 

71) 

for       -pa-m        of       external 

application   of.   li],    \\> 

-, 

,  |.  HI.  'Ill's     III     .  .bc-l|  \    ,     ~.', 

-phincter  of  urctl  ra.    l:;n 

effect-.    :i05 

'  '"  '"''  '">  -  ls-  -'•"' 

d  .uloureux.  50ti 

I-!.-.  -trie     c.  nti.-ct  ion 

'"- 

tor  varicos.     veins,    127 

torfunincles,  7n 

and  u  a  t.-r  conipa  n-,|    5i  1    5  1 

"i  -tiona!  -our,-,-,  55 

tor     motor     distu'-bat 

animal  _TOH  ;  h  and.  71 

'rom   ch.-mic   process,--.   51 

o;   -toiua.-l,.    i:;| 

vital   pr  e.s  and.  51 

Irntti      -ont  ad    ,  it    .  li--m 

for     n-i,  sei  lar     paral; 

-,   . 

ipplications  of,   .Ml 

metal-.   55 

:,  1  :; 

iii.-t  h.  ..  1-.  o  1 

•  •   un  .-ry-i  al'.ix.at  ion.  55 

lor  neuralgia.  71 

-Ml.ipsl-,    111 

in.ni      elcctroinatrnc!  ie      in- 

for  neurasthenia,   52  t 

IN'DKX 


^  par.itii.-.  'l! 

ill       con.-tnict  l 

and    I  •".  'I'M   jar-   arrant:1 

in.  ir 

L'l  I--         Vacuum         el 

trode-  cuiiiicct 


p-  I 


fr-.m,   Is 

.in  mL-ement  .if,   Ml 
H  ik<  r,     for     s-ruy     produc- 
tion, 71.1 

paper  disk,  :«7,:«.x 

t..r  UnntKcn-ra\ 

work,   .i7.   .{.s 

-  il.-initi    chlnrid    as    desic- 

cator fur.  .i'.i 
i  in-  Hi.    I'.i 
carriei    '  if,  -'_' 
i  haiL'inL'    I  ,i'\  d'-n   jar   from. 

_'tl 

•  •  -  l.ru>h  i.f,  :i-' 
conio  iif,  .'har^'  in.  :il 
rond.-ii-.T  di-chari:,-  from. 

at   hiL-h  potential.  .'id1' 

•  •"lull  ii-'  r-     in     connection 

with,   application.   4'.i"i 

application.   'ill 
:    \r~onval    hich-fre,|tienc;. 

desiccator  for,  :v.i 
di-chart."-  between  pole-  of, 

J  7  .  _'  s 
drying.   l>\    compressed   air. 

(0 

,     •..    -.p...  -'1 
efficiency  of.    1.1 
ti.-l.l   plat.--  of,  .;i 
[or  radiocraph.%  .  7Hi 
ior  s-r  •-.    work.  71."..  1  I'll 
miiliampermc,  71'. 
panllr-l      -park       with, 
71'. 

1  1  i  in.  71'. 
li.  tn 


.-,11.     .M7 
:    Vr-onval.   H.', 

Ho  <?.  ..i  .;7 

•  irtiriK  of.  .;i.    tl 


ic  machine.  1'itTatd  safety  Static  wave  current  for  lo.-o- 

./•-ray  tulic_with,  7O.1  motor  ataxia.  .11:! 

polarity  of,  ;<7  for  muscular  adhc-ion- 

chanV'inK,  W  and  si  iff  joint-.  71 

p..l,.  chain.'.'!-  loi,  :i'l  for    pr,,-t;it  iti-,    .Ixi; 

-7.  L'S  for  pro-tiitil  i-.  .",sr, 

principle  of,  I.':;,  :;o  for     sacro-ilia'1     siihluxa- 

"luantity.  capacity    and.   I'i  lion.  71 

room  in  which   kept.    II  for  sprained   .ankle,   71 

rubber  as  substitute  in.  :17  for    toting     -ciatic    ncii- 

-en-itivcncs-  of,  :<'.!  riti-,   .10! I 

-uiiplc  friction  upe,  :il  moditication,  'it 

-i/e  of,  :{!!  o/one     inhidiition-     with, 

-park-trap      in      connection  'ii.  ii.1 

with,  70:;  lo     prostiite     tor     ironor- 

-tartini:  of,    11  rheal   rhi'iimat  i.-m,  77 

tension  of.  -1.1  Steel,      maiznet  i/.int:      effect      of 

I'oepler,  XL'  d\  namic  elccthciu   on.   HI7 

to   excite    Holt/  machine.  :           particles    in    eye.    elect  roniiiL1- 

:>_',  :i:i  netic  extraction  of.  -l.lt 

un-laked  lime  a-  de.-iec:iloi  Stein'-  phi-tic  radiographs  ,  ss.",, 

for.  10  xxi  i 

voltupc  of,   717  j     Steno-i-  of  e-ophacu.-  from  m, - 

diiistmal    tumor,    radioj:- 
raphv  of,  (l!  1.1 
radiography  of,  '.»'.'! 

.r-ray  tube  connected  with.  >icp-doun     transformer.-,      llij, 

70:5  in:-!,  in:,.  71:; 

excited    in  .    opera!  ion.  a.-  rectifier,    111.1 

li'.i'.i  uroundint:  one  hole  of.  :-H,.1 

modiditie-     for     pre.— lire     in-          Ste]i-up  trail-formers,   1',-'.   lti.1, 

filtration    with   jiain,    71  7t:', 

re-onator    eflluve    for    hr-rpe-     :  current  from,   I'ld 

zoster,  7:-;  .r-ray  work.    ll',i'i_ 

-park,  application,   l!i.1  Sten-odiojtr:ii)hy,  s]7,  x]s 

eounterirritation  from.  71  value  of,  s]x 

effect  on  ali.-orptiori  of  exu-  without  -tereoscopc,  MS 

d.ates.  ~'2  Stereoscope  for  exiiminiiiL'  raili- 

lor    acute    muscular    pain-.  ojrraph-.sl7.xls. 

7:^  mirror.  PIL-.  on's,  x]7 

for  chronic  constipation,  7:<  -tereodio^r:iph\    without,   sis 

for    exophthalmic       t'oit,-:-.          Stereoscopic   fluoro-copy,  MS 
.IL'H  plate-holder.  ''7.1 

radionr.'iph\-.  sir, 
in  dentil!  work,  !M,| 
of  ant  rum.  !'s, 
of      conirenilid      i|i.-li "  at  ion 

of  hip.  1071 
of  ,-thmoid  c.ll-.  !ix7 
of    forcimi     liodie.-    in     •  ra- 

n m n..  'ii  i', 
in  neck.  '.''.'1 

.    l!'s  of  frontal  sinus.  '.', .", 

revuL-'ive      .and      d.ti\:i'i\'  of  lower  jaw ,  !Hi.1,  '.Hill 

effect.-  from,  7!  of  pneumatic  -mu-c..  '1x7 

-tiniulu.-        to        resi.-tanci  ,,i   ur'm:ir\    calculi,   lo.lii 

ayaitist  di->  :,-,  .  72  St,  rilitv      froi'i       atrophy,     el,  ••- 

Ionic  ,-ff,  ct-  of.  7-' 
vasodilatation   :i   ,,  coi  .1  n 

,  ffect   of,   71 
,lt  meter    to    m,  ii.-un    diff,  r- 

.  lie,      in     l,ot.-nti.-,l     at     pole- 
of    f.lbe,    Sol 


rho-i-  of  livr,   7:. 
-    -     induration     in     tt  m 

.71 

.11  i 


1-.. 

b-    i;al\i,ni.    ciirr.  nt.   1st 

t,  d   induction   -ii'11  1-.   , 

|s| 

i.-     l.ecln       'iirrent,    tr'.: 

I.       vari.-ible    current-,    law    of. 


INDIOX 


Stimulation,  cerebellar  localiza- 

Stomach,    cinenialogt 

,phy     of, 

tion  bv,  310 

author  opposed   I 

i,    1033 

cortical,  33!).  353 

diseases,   galvanic   c 

urrent    to 

eye  muscles  in,  3IO 

pneumogast  ric 

tiers  e   in. 

perspiration  from,  3  10 

131 

current   for,  331) 

high-frequency  ci 

nent   for, 

degree  of  excitability,  335 

(109 

l)ii  Hois-Hevmond's  law,  312, 

electrization  of,    130 

313,  3X7   '                                                          effects  on  secret  ii 

n,  350 

effect     of    carbonic    acid     on,              fats  in,  radiographs 

of,   102s 

312                                                               fluorescent   media  ii 

,    1235 

Hoorweg's  formula  for,  3SS                  fluoroscopy  of.   102:' 

in      neuromuscular      prepara- 

author opposed  t< 

,    1031 

tions,  reactions  to,  331 

foreign     bodies     in, 

localiza- 

law  of,  312,  313 

tion.    102S 

Du    bois-Kevmond'b,    312, 

function,     desmoid 

test      of, 

313,  3S7 

radiographs-  in. 

1029 

monopolar,  331,  33.") 

electricity   for,    13 

) 

motor  points  for,  335 

hour-glass,     radiography     in, 

muscular,  335 

1030 

contraction  from,  313,  335. 

infant,  radiography 

of,   1029 

See    also     Muscular    con- 

nuliocinematograph 

vof,  dan- 

traction. 

gers,  1033 

in  scries,  33ti 

radiographs-    of,     1021,     1032, 

monopo  ar,  335 

1033.    1011 

body,  31  1 

Slid    in  1  <'.~t  Hies,    i 
tion  for,    1021 

Cst       posi- 

nature  of  excitability,  384                    applied     to    desn 

oid    test, 

peripolar,  33S                                                       1029 

tetanus  from,  337                                     bismuth  emulsion 

in,  1023, 

through  unbroken  skin,  335    '                  1021 

tripolar,  33S                                                      meal  in.   1021 

nervous,  353                                                      fixulst  utTs  passing 

through. 

application,  335                                               102s 

bv    currents   of   brief   dura-                   intensifying  scree 

T  in,  1033 

'  tion,  315                                                   iron  oxi'd  in,  1022 

duration  of,  3  Hi 

metallic  emu  sion 

in.   1023 

Hoorweg's  formula  for,  3SS                   position  for,   1021 

1022 

laws   of,   3S7                                                     technic,    1030 

motor   effects   on   stomach,                   zoolak  in,    1022 

350                                                          secretions,    elect  riza 

tion   and, 

nature  of  excitability,  334                    350 

peripolar,  33S                                         ulcer   of,    .r-rav    clia 

inosis   of, 

reflex,  317                                                      1025 

s]iced  of,  3-l(i                                  !     Stomach-bubble,    1031 

tripolar,  33s                                             and    induction    coil 

for  x-ray 

two  successive,  response  to,                   work.  71S 

313                                                          care  of,   102 

wave    of    contraction    and,              charging  of,  102 

331                                                               from     alternating 

current  , 

Weiss'  formula  for,  3SS                               103 

of  cerebellar  peduncles,  310                        from     direct     cun 

cut.     102, 

of  cervical  sympathetic  nerve,     i                    103 

effects,   3!s,  319                                            rectifier  for,    103 

of  facial  nerve  trunk,  3Sl>                       chlorid  type,  101 

of  heart  ,  350                                                construction  of,    101 

,    KH 

reflex,  modified  by  poison.-,               cooling  of.  while  s  i, 

Iding  cur- 

;  >  5  2 

rent,    1OO 

of  median  nerve,  3sii 

Kdi-on.    102 

of  myocardium.  352 

l-'aure's,   102 

of  nerve-center,  352                                    tirids  of,    100,    101 

of  phrenic  nerve.  3xi',                               m  multiple.   Hit; 

of  pneumogastric  nerve,  effect               in  parallel,   lot; 

on,  319    351                                                  in  series,    1  do 

of   sciatic    nerve,    reflex    va.-o- 

dilatation   from,    35O 
of  spinal  cord,  311,  352 
peripolar,   33S 
pi  unts  of  elect  ion,  335 
reflex,   3111 

t  rausmission      of,      i  ime      re- 
quired.  329,   330 
t  ri]  ii  ila  r,   33s 
\'.  i  i--'  formula  for,  3xx 
Stini/iiiLr's   table   of   faradic   ex- 
citability ,    UK) 
of     neuromuscular     excita- 
bility, 45li 

Stokes'  theon    of  ,r-ra\  .  i'i!i  I 
Stomach,   albuminoids'   in,   radi- 
ography of,    lO2x 
atom   of,  high-frequency  cur- 
rent   f.  i'-.   tiO',1 

carbohydrates    in,    electricity 

for,    130 
radiography  of,    1029 


;i  iL-hl      w  in  .     n.:i:: 

dia-c d     by     dei  trie     IT, 
rent  thnmgti,   H'T 

netie   pole-,     1 1  C 

nt.  rnal  i;-.  .  d7  I 


Stricture     of     esophagus,      elec- 

lricit\    ior.    112 
electrolysis   lor,    122 
radiograph  v   in,  (I'.ll 
of   lacrimal   d'uct,   electrolysis 

for,   122 
of     urethra,     electrolysis     for, 

120 
electrolytic     dilatation     of, 

120 
rectal,      high-frequen<'V      cur- 

rent for,  (i!3 
spasmodic,         high-frecmenc\ 

current  for,  5M 
String      electrometer,       Kintho- 

ven's,    175.  323 
Strohl's  method  of  localixat  ion, 

MIS 

Student's  resistance  box,   232 
Submarine  cable,   235,   21s 
Substitution    to    test    resistance, 

22s 
Sudnik's    high-frequency    treat- 

ment  of  gonorrhea,  5S5 
Sulphat-    of    copper   as   electro- 

lyte,   !(1 

of  radium,    123!l 
radicle,    liberation   of,   in   vol- 

taic cell,  SL' 

Siil])hur,  effects  on  plates,  VI3 
Sulphuric     acid     a.-    elei't  rol\  te, 

i)0 
Sun-bath    in    chronic   infectious 

osteomyelitis,  (i!U 
Sunburn,  red  lij-ht   for,  (isti 
Sunlight   in  treatment  of  tuber- 

eulosis,   (i!U 

Superior    maxillary   sinus,    radi- 
ographs'    of,     981.      See     al-o 
Att'mm,  ,•<„/;„,,;•„,,/<!/  of. 
Supernumerary    bones,    radiog- 

raph.\-  of,   1096 
Suppurating    wounds,    galvanic 

current  for,    12(1 

Suprarenal    capsule,    Rontgeni- 
zation    of,     for     hypert  en-ion, 

i  r.is 

Mipra.-pmatus,  i>aral\  ,-is  of,    17s 
Surging    currents    for    flat-foot, 

1  10 
electric     apparatus,     Morse's, 

13!! 

Sweet's  apparatus  for  localizing 
foreign    bodies    in   eye,    90'.), 
!MO 
locali/ation  chart,  Weeks  and 

Dixon's  modification,  !I1H 
localizer  lor  foreimi  bodies  in 

c;  e,  '.)()!  I 
Switcii-board    for    electric    bath 

s-urrent-,     13s 
Switclies,    135,    13ti,    21  is 
arcing  a',   prevent  ion.    1  35 

135 
for       condenser       discharges, 

double-pole,    3X9,    390 

knife.   13C, 

S\  i  .  -i-.  elec'trnlysis  in.    Us 
hiL'h-trei|uet:cy     eurreiit    for, 

radium   ra\  -  in,    1270 

x-ra>    in,    11  75 
>•  lunietrie    gaiiLTeiie,    galvani' 

•ui-retit    for,    127 
Symphy-i-  pubis,  non-union  of, 


1(  li  ill 
tiurtnal,    Hlon 

-  paration  of,    Kir.ii 
.  t,.  ope,      .-hLiroform,      farad 
-  urrent   for,    12'.' 
i:oviti~,     bipolar,     d'\- 

current    statie    ij,d  id   .-n-s 


iii,  1  I  1-'.  I  1  l:: 

iiifi:tni!ii:itiiiii   <>!    bunes,    radi- 
um iphy  in,   1  1  l:; 
rhino..c|eroma,  j-rav  in.   I  17!' 
rinumnyi'liii,     electricity     fur. 


['abeti"  arthritis  uf  knee,  iudin 
anaphoresis  fur,    1(17 
•  ' ,    radiography   in.    Ills 
I'alipe-     ei|umu.-.      radiography 

in.   lust 
l'ani:ent     L'alvanumeters,      1HO, 

I'M 

uf  an-].-,   nil 

ink  development.   s7H-xs] 
:pe.  irisi.latim:.  -Ml.' 
ippitiL'      line      fur     additional 

nutlet,    L'l:j 

irm  i  i >f  jr-r:i.\   tube,  li'.'1.',  7(K) 
!•-•!    bones,    fracture  (if,    ra'li- 
oj.'raph\    uf,   lost.   Ids.-, 
irsiis,  radiography  uf,   IDS:', 

e-te.    effect    uf    electricity    on, 


result-   in   study   uf   muscular 

current-.  -'s;i 
TI-I  T  :.,    i  ••:-.  it  i'  -    I?:,    fluuroscopy 

e;.  -•-     a!      roots,     tuberculosis 

from,  '.>'>'•'> 
,  :•.    •-   of   imperfect    develop- 

mi-n'.  I1'1" 

.  .  •  •  u-tion  .  if,  painli  -s,  'i^ii 
fluon.-copy  of.  '.'17.      S..<.  ul.-o 

l>-"  •    !'.<<"r  ......  !•:!. 


rial.-  by 

.  toplion  -i-  for,   in.", 
iiii-n:pi.-il,      :;  .    '  >-'     ; 
'•]  7   ''I1' 

i,   .'iO_' 

'I  .  '     •.  •  '       '        •         '     ••: 

..  ,  .......      ,;j| 

,        :         '        -:.  Jl, 
moving 


r-liTtrolytrs  outsiili-   bat- 
tery, L'li'i 
in  battcrii'>.  L'lll 
cfTiM-i    on    m\-o(rrapliic    diart, 

X  I  _' 

on  rc.~i-tancc,  L'L'I 
niii.-''u!ar      contraction      anil, 
:;x:i,  :wi 

ii'-inini.'.  '.is 

of  cuiiihictini:  wire-..  L'lM 
'I'l-mpurary    U-cth,    railiuirrapliy 

uf.  '.I.',:; 
'IVndcrnc'ss,  cutain>(m>  an^a-  uf. 

.'>(  1 1 
Ti-nu-yiiuvitis,    diathf-rmy    fur, 

037 
Tcn-iun.  Itiii 

rlectri'1.     hydraulic     pi'c.--un- 

and,   comparison,   7^,   7'.i 
Tola  coil,  .Ml 

hijrh-froriuency  apparatus,  o."i] 
coil  for  .r-ray  work.  7!_' 
current,  .I'll 

applicatiun,   ~>~>l 

type  of  portable  j--ray  out- 
tit,  7:-;:-; 
transformer,  .'i.'>l 

<.'la.~s       vacuum       electrode 
eunnected   with    ]>u!e   of, 

i.iiipi  Jar  ./"-ray  tube.  77o 

\  acuum  liplit',  ii.")-',  o.M 
Testicles,     effect    of    j-ray    oil, 
1 1:«,  1  ::il 

neuralfria  of,  .',1  1 
TeMiiiL'  for  nerve  injury,  -I'll 

nerve    at    time    of    uperatiun, 

l.M 
Tetanic    contraction     for    .-inu- 

soidal  cnrri'iit.-,    !  11 
Tt  tarn;.-,  electric,  :-;:',( i 

c-xcitabilitx    rif  heart    in,  .'J.'il 

from  low-tension  current.-,-".!  1 

reflex,  :;i7 
Tetany,  l'.r\>  reaction  for,   l~>7 

• .   ~>~>~> 

Theory,  Nenist'.-,  :;:!! 
'J'hermo-eleetric  jiile,  US 

thermometei .  (.'^ 
Thermo-eleetricit\  .  '17 
Thermographs,  lifts 
rl"hc'nnoluminescen<-e,   .  \~> 

•  lllTIIIOH    'l    el   He,     '^ 

I'heri          ejrii'    n.easurenn-nt    ..' 

.r-ra\  .711 

Therniup,  :..  rial  on,     1 1:11.      S.  . 
also  l>:.i'>:.rn,  l. 

\  • at,  .  lei  trie,    I:--. on T-. 

niiei 

••.    |uei|i       current    for,  ilu'M 
!  :  nrl  .       irterie,      ,,f, 

iadio(.nipli.\    of.   1  !.'». 

i! up\     n!',     111,    I 

'       pi          of.     1(17  J 

|,,.-.      '-         lateral         plate- 

el        •    .     HI7.' 

rhiuMnamiii     !oi      keluid.     C.L'S, 

!  1  7', 
II    rd  nerve,   paral.s  -i-  ut,    171 

,.!,.;-,     I'.MI 

llie,  7'll 

I  '  un  p-un   iluu-lun  tura-e- 


ri'si-tance    ot    fralvanom- 

eter,  j:;:i 
Tluirimn,  !L'7'.i 

pure,      etTective      emanation., 

from,   ll'.'.L' 
ra.\-,   IL'H 
Thr.'lkeld-KdwardH     devel,,|ier. 

SO" 

Thresliold  of  cuntractiun,  Mr, 
Thumb,  double,   10H7,   Kills 
Th\  mus  trland.  hypertrophy  of, 

j--ra\-   in.   1  l^S 
Th\Tuid   secretion   increased   by 

(iiathenn\  .  l'iH5 

Th\  roidectumy,       effect       upun 
ipi!i-ps\-  induced  hy  stimula- 
tion, :i.'lll 
Tib:;i.  fiacture  of,  radiofrrajihy 

of,   107.'i-  1077 

uniun       with       malpusitiuu, 

radioi-raphyof,  107r,,  1077 

Tic    d'  iiiluureux.        See     '/>"/'"'- 

inn!  ,  '  <inilni<i. 
Timer,  ai'.tumatic,  fur  .r-ra\'  ex- 

posures,  Mi:', 
]-!a-t  man,  lor  ,r-ra\"  exposures, 

st>:i 

Tin-fuil  as  screen  fur  .-uft   ray.-, 

71  is 
Tinea  capiti.-,  (lowers  of  sulphur 

in.   1  Isij 

reinfection  from,   1  Isii 
.r-ray  ill,   11s] 
of  beard,  .r-ray  in,  1  1  s:i 
Tinnitu-        auriuni,        hi^'li-frc- 

(juency  current   fur,  lil'.l 
Tintuniete-.   r.ovibond-Corbptt, 

1 1  :>s 

Ti-siies.  anima!,  elect  rul>  -i-  of, 
L'H7.      Sec   also   El<-ctrn!u*i* 

mat  tixxiii*. 

am  •.-tint;  seeundar\-  ravs  frum, 
choice    of    filter   or    cellular 
Biicky  screen  for,  SHI 
chanties     under     static     elei  - 

t  ricit y .  71 

effects  uf  electricity  un.   -".'o 
influence  un  j--rays,  s:-;:j 
usci'lator  for  iruut,  r.ut 
fur  obesit\  .  i'ili:i 
for  uric-ai'id  cases,  HOI 
Hanfeld,  no:-! 

secondary      rays      aiisintr      in. 
sUppre.-.-i<in     of,     lilter 
closc   to   jilate    for,    s;;n 
uf  radiocra]i)n    iiml,   s-.; 
sc-n-ibili/atiun  ut,  to  liu'ht,  "si 
Titubator,  Ss_' 
Tuepler  stat  ic  macliine,  '.'<- 

lo  e\cite   I  lultx  machine, 

'I'm  -.  r  idiujraph\  of,  Insn,  IDs.-, 
lie,.,    ,,f,    cataphon  - 
-i-  for,   lo:'> 

i;     in,    lL'1'11 
•  •    .   •        M  in,    IL'O 

I'ul  '       . 


1H7 


•      •  .•      •      .  •••..• 

• 


|>equenc\      ,|,  I        | 

!..r.  OKI 
I  1,1,11      .'1    1m- 

•  l.  ettiei,,    and,  .M 
I'urpur  r.  cti.ele.t'lii      I 


INDEX 


Touch,  sense  of,  effect  of  dec-        Tousoy  meth<xl  of  te.-tiiiK  mus-    I    Transformers,  fl'Arsonyal,  miis- 

' 


Toll-ey',    C.,-,7',     1  I.V.I 

arrangement    ot    veiitril    tubi 

and  -park-trap.-,  7^ 

aiitoeondensat  ion  method  for  plate  tunnel,   IO.V,) 

hypertension,  .">77  portable  j--ra.\    t.utlit,  7:il 

hacking        for        radii, f raphie  po-ition-    for    radiograph; 

plate,  MiL'  (  'olles'   fracture,    ID'.IO 

bifocal   tube  for  radiographs  ,     j          power  of   /-ray    from    vat 

bllie-lighl    therapy   with    heat,     '          precaution-   in   ca-e  of  break- 

Iis7 

board  eompres.-or  in  radiog- 
raphv  of  urinary  calculi, 
111.-,! I,  in:,  1 

[•(  llular  diaphragm  dangerous 
in   renal   radioiiraph\  .    It  >.".."> 
contact  diaphragm,  SOI 
dental   flii.,ro-cope,  <»L'U.  in' I 
Use     abandoned     b.\      au- 
thor. st7 

device  for  applying  parallax 
method  rad'iographically, 
Mill 


liar  cont  ract  ion,    l.Vs,    i;,'l 
dice  j-ra.\    a])paratn-,  7'.',  1 

rthodiagraphie  radiography,     !  with  .-mall  solenoid,  -VH) 

!i')7  lor  jr-ray  work,  7i:i 

(  iaiffe'-.    71.: 

[)! 111'   iple    of,    71  1 

,-afety   valve  of,  71.". 
high-ten.-ion,  7  115 
hyper.-tatic,   I'iffard,  70.  .".tS 
Mahuiuin's,  7li; 
open     or     closed,     for     r-ray 
f  x-ra\    tube,  7M',  work,  7.M) 

radiating  cellular  diaphrairm,     |          outfit,    (iailTe's,    for    high-fre- 

S_>C.  (|iienc.v  work,   ~>\'.\ 

for  attachment  to  tube  riiuj,  clo.scd  magnet,  1_'O,  lU."), 

stand,  M-'Ct 

to   JT-Tiiy    tube.    ^l\ 

u.-ed    near   or   at  ladietl 

to  x-ray  tube,  sj.s 
screen,     placed     between 
patient        anil        plate, 

H2N 

radium     applicator,     anal\'.-i.- 
of  radiation  from,   I -'17 


Kit) 

to     reduce     trolle\--ear 

eurrent,  _']."> 
rotary,   1J7 

to 'reduce'    trolley-car    cur- 
rent, I'l") 

.-te])-down,  111.'.  ]>;:',,   1C,.-,,  71X 
a.-  rectifier,    10") 

step-up,  IC.L',  }>;•'>,  7t:: 

current   from,   lliii 
for  j'-ra\-  work,   I  till 


elect  rotherapeutic   table.     1  !."> 
experimi'iit.-  upon  elect  rir  a'1- 

cidents,  :;c,:; 
with     solution     expo-ed     to 

radium  rays,   lL'('i7 
film  clip,  !i:j.S 
!:.i.  r    close    to    plate    for    -up- 

ari-imr  in  tissues,  v:-;il 
flui.ro  meter,  s|  1 
frame  applied  to  head  to  indi- 
rate     median     [.lane    for 

-inn-   radio.:rapli\  ,  !)77 
for  holdiiiu'  [ilate  in  an   in- 
il  po-it  ion  for  L'a-t 


unreel  ified,    as    r-rav    fenera- 

tor,  7  1M 

ventnl  nibe-  and.   1C,, 
for     lii<,'h-frei|uency      treat-  \Vaite,   ,  ~i() 

merit       of      rheiima-  \Vapi)ler,  7."i() 

ti-m,  C>()0  Transilkimination      of      frontal 

of  -ciatica,  .VI")  ,-imis,  !isl 

for      i-olated       l.e\'den      jar          Trari-illuminator,          C'oaklev '-, 

.-park.    l!i!i  H>«I 

for      ront-renothe'-ap.v      for    ;     Translucency,  C,!)2 


for  j-ray  application  forleii-  '         placements,  1070 

kc'iuiii,   1  L'l  T>  Trail-plantation,         excitability 

test    of    loss    of    detail    in    in-  .         after,  340 

ten-it  >  intr  screen-.  Mill  :      Tran,-ver.-e  ;irch  of  aorta,  aneu- 

nte.-iiiial        radiography,      '          t  liio-ina  ruin    treatment    of    ke-  r\  -m  of  .  radiography    of,   1  1  K  1C, 

l(i::'.i                                                         loid.   117C,  Trajx'zius,  paralysis  oi',   177 

unit  oi   power,   ll'lC,  Tray     development     for    dental 

and  [|tiantit.\  .  1  IV.i  ,         films,  '.W 

use    ill    triple    pha-e    currents  i     Tfencli  foot,  adhesions  of,  static 

in  an  .r-ray  generator,    1  1'>  wave  current-  for,  71 

vacuum    electrodes,    ot.'i,    'I'M  Trianiiiilat  ion.    loealixation    by, 

vertical  liltn-currier,  !C'  '.'Oti,  <i()'.i 

r-ra\    apparatus,   -on  Ti'itacial    rn-urali;i:i,    '  ludin    n-s- 

•   ibc,    IJIs  niijitoi    for,   .V.lli 

do-aire  ivith,   l-'l'i  i     Trijieminal    neuraltria,    "iiil,   .',11  1 


figuration  method,  :,-,_'.  .",c,  ; 
fralvanic   and   faradic  appara- 

III-.    (Ml 

tr!a-   mount    for  dental   films, 
'.Ml 

.   ,  \po-un  -,_  IOH 
hiirh-frci|ueiie\     treatmenl    of 

indirect   -pra\    elect n  nie,  li!' 
lateral   plate-holder,   '.'71.   !l7."> 
ti  rad       i  iph      of    iliijrh, 

Io7_' 

'  "  u-e    altandoned  '  b'      au- 
thor. '.'.'1 
mea.-uremi  nt    t  ,1   ,r  i:r,    p,  iwer, 

I  1C.  I  I_'C,II 

mi  Iff  - ml,  li.",7,    1  I.V.I  Ti-i.  h,  a,     radiorr:i| 

e.|iiivali  nt-  o!,    1  lliD  H  I'  1 1 

manenl  dental  ardi,  !IUH,  ,r.  ills 

!Hi|  Kroti  a  .  ei    Ian  p  f..r,  C.V.I 

ol    do-au'e    in    P  :  •  i  liu-u"  in.    I  Jill  .    !  J77 


dcohol  injection-  for,  .".o." 
Befconii'''-  treatment .  .',1 1 1 
c-ataphoresis  tor.  .".(U 
cont  inuous  current  for,  .V  i.", 
elei  t  ricitj    for,   .Mil ,    :,i  i| 
di-tributii.n     nt     current, 

.VI.",, 

effect.-,  ."id.") 
endodia-cope  in,   77-' 
larailii    i    irrcnl    lor,  .Mi:; 

hiL'h-voltaire  t  teat  merit , 

.",( 1 1 
I.ediic1-  treatment.  .".(II 

aft.  r,   1  I1':; 

radium  lor.  .VI".,   U7- 
inir    c-ur-  :-alic\lic     ,-atapliof. 

inn 
1C,C,    I tvi  -tatic  dectri.  in    I    r,    .mi 

'  Tt'l  -.    !1- 

LiT.-iit,  i.;j.   ;  -7 

for      pn.irn  -sin       inu-enlai 
l-Jll,    1C,:,,     •  atioph    ..",11 

terrupl 

. 


IXDKX 


lOii                                                                      by,  disruptive  nature  of,  (>,"il 

t  libel  cailar  sera,  ti7,X 

h\  dro-elee;  rie  bath-.    117                          .r-ra\  .     Sec  l\<~uitiii  ii-rm/  tttl'<*. 

(in   ant  is  ciioms,  (177 

Tri|ile  phase  current-.    1  Jx                  '     Tubot  ympanit  is,  elect  ricits    for, 

on  bacteria,  ti77 

and      ineeli:!nical      move-                l-il 

on  chlorin,  fiT'i 

incut,    comparison    be-         Tumors,      intrathoraeie,      radi- 

on   chlorophyll,  (177 

tweell,    1  Jx                                                    ovraphs    of,    101!) 

on  cobra  venom,  d77 

in     an     j'-ras      generator,     .           mcdiast  irial,     csophaL'cal     ste- 

on    colon   bacillus  in   cul- 

Tou-es 's  u-e  ..:.    1'jx                             no-is    from,    radiography 

ture.  Ii7!» 

ll-c  of,    1  J'.l                                                                    ill,    '.l!)"> 

(in  diastase,  Ii77 

Tripolar  stimulation,  MX                               radiography  of,   1010 

(Hi   dielectric  liquids  and 

Trollcs  -ear  current-,  _'  1  1                              (if  bones,  radiography  in,  1  10~) 

solids,   C,7(i 

circuit-breakers   for,   J17                      of   brain,   radioirraphy    in,   !Klt 

on  esc,  li.xj 

for  elect  rot  licra  pent  ics,  Jl.~>,              of  joints,  radiographs-  of,  1  10.") 

on  .rases,  t',7.1 

Jir.                                                        of  him.',  radiography  of,   101(1 

on    human    blood    serum. 

rails,    ground    connection    of,              of  neck,  radiography  of,  !Ki."i 

(17,X 

L'lii                                                                 of  orbit,  radium  in,    l_'7."i 

on  inulin,  (177 

Trophic        disease:-.         hiuh-fre-              of     pituitary      body,      radiou.- 

on  inscrtasc,  Ii77 

queney   current    for,   ox:;                               raphs    in.  (M7 

on  micro-organisms,  <i~S 

Tropical  ilevelopins.',  V'O                             of  s  ihenoid  cells,  radiography 

on  milk,  i',77 

Tropic-,    j--ra\     work     in.     dilli-                              of.  dx(i 

on  nit  rate  of  silver  paper. 

cultie-     due     to     atmospheric                        .r-ras    in,    ll'JM 

(17!  1 

moisture,  xr,:{                                            Tungstate     of     calcium     screen, 

on  nitrates,  1177 

Trouble,  locating,  Jlo                                            ,xo:', 

on  retina,  (i.xj 

Trunk,    radiography  of,   bromid     :                    home-made,  x():{ 

on  saccharose,  (i77 

paper  for,   xd'i                                              Tung-ten    electrode    are    lani]is, 

on  saponin,  (i77 

Tubercle    b.acilhis,    effects    of    .r-                     (ilill 

on  sera,  1177 

ras    on,    MX',,    llxil                                         melting-point   of,    1JJO 

on  starchy  solutions,  1177 

Tubercular     arthrii  i-,     galvanic     i          largel   x-ray  tube,  7(11! 

on    toxicils    of  strophan- 

current    for,  danger  ot  ,    (Jii     j     Tuning-fork     for     timing     nivo- 

thu.-,  (177 

sinus  of  face,   radiography  of,     '          graph,  :i]x.  :j]() 

on   tubercle  bacillus,   ti7x' 

11x7                                                  .     Turbinatcd   bones,   radiography 

on  tuberculin,  (177,  t,7x 

Tuberculin    test    in    bone   tuber-              of,  (ix7 

on    various    organic    sub- 

eulosis,   11  JO                                                 Turbine     interrupter,     mercury. 

stances,  tixo 

Tubcivulo-is  caused  by  alveola!'                Ropii|uet's,  7J.~> 

on      \\assermann      reac- 

abscess, (i,",:-;                                        Turner's   method    of   measuring 

tion   for  syphilis,  (177 

figuration  f,,r,    "ii'il1                                    resistance  of  blood,  M'.Hi 

erythema  from,  (177 

irenito-urinars  ,              hit:h-fre-          'l'«o-f!uid    tlicory   of  electricity. 

ers  1  hropsia  from,  (isl> 

quelicy   current    for.   ox  I                        1(1 

fixation  of  microbes  b\  ,  C,x() 

hirh-fie,iuenc\-     current      for,          T\  phoid  -nine,   radioirraphv  of. 

fluoroscence^if,  Ji71 

:,7n.  ."»x'i,  ii(i7                                          1017 

for  conjunctivitis,  (ixS 

joint      and     skin,     blue     li./ln 

for   conical    ulceration,   ti.xS 

treat  nient   for,  i',x7 

for  facial  neuralgia.  1  1!U 

lar.MiL'eal.       mercury       vapor 

tor  locomotor  ataxia,  ti.xs 

liL'ht    for,  lixx                                        1    n  HI;   and    cancer  of  stomach. 

tor  lupus  vultraris,  (i7ii 

mercury    vapor  Unlit    for,   ()."io                    dilTerential     x-ray     cliaynn- 

for  nciirit  is,  oOJ 

of      bladder,      hi^h-frequcncx                     -1-,    lO-'.'i 

for  scalp  treatment,  (iM 

cm  '.-lit   for,  :,x!                                     from   radium  rays,   1  L'."i7 

for  sciatica,  ."i()S 

ol  bone-,  radioL'raph\   in,   1  1  JO                hi;/  i-frei  iiieney      current      for, 

for  skin  diseases,  -1JS 

.;'  -l  fl  .     in,     1  1  Jx                                                            lij'" 

for     sterili/al  ion     of     milk, 

ot      carpu-,      radiotrraphs'      in,                of  cornea,   nil  ravii.ilet    rav   for. 

<i7!l,  tixO 

11  JO                                                                         I'.xx 

of   \\atcr.   r,7!t.  ti.xO 

of  dhow,  radiography  in,  1  IJx              ,,i    loot,    perforatitiL',    faradic 

lor    ssphilitic    skin    !(-si(ins, 

ol      eye,     experimental,      radi-                     current    for,    IJ7 

1  17d 

•     His   le-ted    in,    IJ.'iX                            of     ejr,    xine    calajiliori'sis    for, 

for  .r-ray  dermatitis,  (i.sS 

ol  foot   bone-,  radiographs    in,     ,                lox 

from   condenser  discharges, 

1  Us                                                               ,,;       rectum,       hinh-frequeney 

(ill!) 

ol  L'land-.  .r-ras'  in,   1  Is.',    1  1  xx                    eurreni    for,  lilM 

from     ".'lass     vacuum     elec- 

ol  hip,   radioL'raphy  of,    lor,".                 rodent,    radium   in,    1J71 

trodes.  o7J 

Si  i      al-o     I/'--'.'.                              ..    :   r,     i!,,    1J10 

ce,  .crated  b.s   Crookc-'tllbe, 

.r  r,   ;    in.    1  I7'.» 

r,7."i 

'    .  •      lioirraphs   in,   1  1  JO     '      1   Ina,  iliniri..-e,,py  of,    loxr, 

iom/ation  by,  d7.'i 

r   ra.\    in,    1  |x!l    '                                          fracture     of,     fluoroscops      (if, 

.,1  cas  by,  t',i:j 

'  >!         1    l.llji  -•.  ,         hifh-l  requeues                                1  Ud'l 

ii  it  is  fiom,  ti.xS 

o(rrapi\     n, 


r:idinirrapli\    of,    Kix'i 
I    Ina;    nerve     para  I  \  -L-   of,    Ixii 
I    llia\  iolet       la,  ,,|..       Haeli      and 

It  ,   I  i'.K  I 

'  lorl'   ,     I'ilTard's     modiliea- 
1  ic  in.   ii7i  ) 


ph>Mo!ocical  ell',  cts,  l',77 
positi\c    and    neyatue    i.ms 

produced   b\  .  Ii7."i 
properties  ot,  li,  ! 

i.  st  tor,  r.7l' 
therapeutic  use  ot,  C,7!t 
therapy,  I'.'.HI 
lieatment    by,   .ri."il 
\\  ater   I  laiisparent    In,   t'.xll 
I    n. lamped  o.-eillations  in  dialh- 
eim    .  o::j.  f.lo 

I    ndeldevelopniellt,    .XX7 

I    ndercxposure,  de\-clopment  in. 


IXDF.X 


I  "ndcrexposure,  development  in, 

lank,  x7'.i,  xxo 

I'ndulatorv     current      for     elec- 
tric baths,    I  !_' 
.if  low   |iotenti:il,    I'.M) 
nature    ot     induced     currents, 

I  .v> 

I    n.  i   ipted      teeth,      fliioroscopy 

nf,  '.Us,  '.Mil 
radiographs    of,  '.»:,:: 
measurement,  !l.">.~> 
I'nipolar  .;--ra.\    tubes,  77:t,   ll.'il 
I   nit   magnet  ic  pole,   17  I 
rnited    States    \:ilion:d    Hoard 
uf     l-'ire     I 'nderu  riters,     regu- 
lations, of,  207    20'.l 
1  'nn-et  ilird  t  ransformer  as  .r-ray 

generator,  7  IM 
I'n-iaked  lime  as  desiccator  tor 

-latie  machine,   II) 
I  "n-triated    iiiiiscle,    contraction 

of,  :;:d 

I  pper  extremities,  congenital 
le.-ions  of,  radio^raphv 
of,  10'.  i:> 

fluoroscopy   in.    10xC, 
fractures  of,  radioscopy  of, 

1  ( )!  l,x 

paralysis  nf,  -177 
radiography  of,   10X(> 

Sclionberii's  compression 

cylinder  in,    lO'.tl 
T'ranium,  'l27,x 

r:iys,      ll'.'i'J.      See     also     lirr.- 

,,urrrl  run*. 
rrhaiitschitseh's    telephone    tor 

ti'-t  itlLC    lleanilL'.     I  I  '.' 

I'reter,  currents  of  action  in,  :i27 

radiography  of,    Kl'it 
I  reteral  calculi,  fluoroscopy  of, 

1051 

positions  lor,   !<).">  1 
iadio.;raphy  of,    HI.Vi,    l().~i(> 

results,   i()li() 
catheter  for  phlelioiith-.    bl.'x 

in   radic.m-aph.\,    lO7,x 
I'rethra,  electrodes  for,  :iK< 
external    -phmcter   of,    spa.-m 

of,  electricity  for,    I'-IO 
hifih-frequenev  elec-tn.de-  for, 

5S1 
stricture    of,    elect  rolv.-is    tor, 


oseop\    m.    liCil 
lor.    lO.'i  I 

•  '.     of,      lll.'ili 

iu-r:ipli\    of,    Kllx 

n  band  and 
mil. Hnble  |,;IK  for, 
1 1  >:,  1 

•  .    ll)»!i.   luM I 


ToUM'.y'sinetliodoflocal- 

i/alion.  ]U.',7 
.r-ray  'or,  ,">s7 
I'rine,  conduct  ivil\-  of,    |M> 
ell'ect.-  ol   hi>;li-fi:e<|iieiic\    eiir- 

icut  on,  .")7."i 
incontinence      of,      electricity 

lor,  -IL".) 

in  neurasthenia,  ol1'-' 
in     rheumatism     under    liijrli- 

freiiuencv  treatment,  ti()() 
resistance  of,  M'.Ki 
I'rtiearia,    static-   elect  rii-it\     for, 

127 

I'terine  contraction   from   >lim- 

ulat  ic  m   of  r-pinal    cord,   .i  I  1 

fibroids,      radium      in,      1277, 

1LI7S 

.r-ray  for,  7U7 

fihroiii'yoinatu,  Tousey's  tcch- 
nic     of     ronttri-notherapx' 
for,   12(17 
r-ray  for,  707 

inflammation,     Matic     .-park 
for,  71 


40") 
x-ray  in,  1  _>:$() 

di>ea>es    of,    radium    ra\'s    in, 

electrodes  for,  Ms:l 
libromyoma        of,        Apo>toli 

treatment,   l.'i.'! 
foreign  bodies  in,  radiojrr.iphy 

nf,  luiiti 
imperfect,  >terility  from,  elce- 

trii-ity  for,  !:>:•;' 
ret  ro II, -\ion      of,      hydro-clee- 

li-ic-  sitz-baths  for,    t  17 
I 'viol  lamp.  i').~>:{,  i)7_',  r,7:i,  r,7s 

for  lupus,  (is'.l 


leuree    of,    iinporlai in    r- 

my  treatment,    I  l-'iJ 

•lectrode,    I'.ix,    t'.i'.l 
application    throiiLrh    e],,th- 

illL',    ."l."lc. ',     ol'p'  I 

(•fleets,   local,   ol'px 
for       hiL'h-  lre-|ii,-ir- . 

r,  nts,  .v,'j 

,1,,-trn  !•  i 
handle  for,  .Vi't 
Iliah    fre,|Ui-Uc\  .    .Vt'.l 
partial,  r,i:, 
perfect,    l',."il 

re.   !:n.    i, I   1 


for  internal   HM-,  r,7  I 
mercur\     vapoi-,   a.-   double- 

curri-nl    ivi-tific-r,    lot 
po-it  ivcl\    chained  part  ie|i  — 

in,  7l:i 
.-tatie      wave      current      ap- 

plied  by,  (if, 

transmission      b\  ,      disrup- 
tive nature  of',  li.M 
.r-ray s  w  ithin,  71  1 
Vagina,    endothelioma    of,    radi- 
um in,   1272 
foreign  bodies  in,  radioyra)ih\' 

of,    KWili 
\'acinal  electrodes,  bipolar,  :;s2, 

li.si; 

trlass    electrode    for    hij.'h-1're- 

queney  current,  ."iM 
N'at'Us  nerve,   ]iaralv.-is  of,    (71 
N'alve      tubes,      7s7.      See      al-o 

\'rntril  liilji:". 
Van't    1  lolT's  lac-tor,  2oo 

law,  :;i  t 

obsei-vatioiis  on  soluble  MI!>- 


tumors,   el,-c-ti'ol\-sis  of,    tlli 
Vasoconstrictioli  capillary, 

from        hi(.'h-fn-i|iienc\        cur- 
rent, .-)7!> 

N'asodilatation.        reflex.       from 
si  imulation  of  sciatic-  nerve, 

:-',:>o 

<ecoi!ilar\-      i  ITect      of      static 

spark/71 

Vasomotor    effects    of    stimula- 
tion  of  p!:ei:iuoi.'astric,   intes- 
tinal, :-M!l 
\  i-Uix,    L'lc,~s\.    for   dental    radi- 

ou'raphx  ,   dlii 
]irint-. 


and     -park  t'aps,    Toux'y's 
an'antremeiit,  7X.X 

breaking  of,  7sil 
construction  ot.  H',7 

tor      (  iaiffe'-      transformer, 


to       remedy       inverse      >\i<- 

p-hartri  .  7xt;.  7x7 
Villard,  7x7 
\\  i-hiii-lt.  7xo 

'.  rnal  catarrh,  ra.lium  in.  1277 
static  \\ave  current  applii-d     •     N'erntca.   .-titaiihoresis  for,  -toil 

/h.  i'.:.  -   -    -•  lor,    1 1H 

1  '-.  "il.'i.  .V)!)  radium' for,   !  Ix,   rjnii 

I,  ."iM  ..-ra\  .    111! 

"-''''  r-r:ij    for,   II  x.  i  I7x 

i  ,c-ra;    '•  \i  -.  -.   i.  •-.*  •:  ;:..-.  x.;7.     ,     \'ersions'    of     uterus,     hiirh-fre- 

n      :-  :'••'-.  s.,  ;.  x  ;(.  s  ;:,.  \,  ,",''.bne.  ',','',  'vi'c'a  ]."•!-'.'•  " 

x|:;  r  -,dio  i;raph\    .  ,1 .  W] 

•  -•.  x:;7  d.pf-.     .rail  •      1 

!       I,   71'.  lumbar,   radioyrai.h       •' .    Ioo7 

'          '  ilator,     low-  r:iiliilttr:i|ili>    of,   c\p,.-  .       lor, 

i-   au'i     .1'  ele.-t  ric  it  -.   i  hi-  iijcli  \'ertebrate>,   i-lTeet  -     .1    - 
.!,  HIT.  ity  on,  Mill 

I,  '-"-1  \  erfi  i 

•I'ulatoi  tor  Nitro  Ken  j   i  r,  -07 

I  \.  -•  -     :       .:-.', 


IXDKX 


Vc-ical  calculus,  hich-frc.iuency 

Voltajre  of  r-ray   current,  meas- 

Voltaic cell,  voltage  of,  measur- 

-park  I,  >r  freeini;,   :>xi> 

uring,  7X1,  7:iS 

ing.  1)2,   1HX 

radiography    of.    lo.'iil.    luill              ozone  production  and,  4"i() 

volt-amperage  of,  XI,  S.'i,  SC, 

cn-i-      in      locomotor     ataxia.                physiologic     effects     of     elec- 

watt.-  of,  X". 

calvanic   current    for.   o  1  .">                         tricity  and,  :>()  I 

/.inc  in,  XH 

\'e-iciihti-.    hiL'h-lrequcncy    cur-               reduction    of,    in    j--ray    work, 

consumed  in,  H,", 

Mill    |.  ,:  .    ,"iSti 

x.,11                                                                 couple,  XH 

Vihrat  ini;  mierrupter-,  x.",7 

relation    to    capacity,    in    pro- 

currents,  IS 

dec!  romau'iiet  ic.    111 

ducing    contraction,     1511) 

nature  of,   l.'.l. 

(Jlleen.    So) 

to  physiologic  ctTects,  2H.", 

pile,  original,  H7 

\ibrati,,n     and     taradic     currenl                telephone   for   measuring,    17s 

vert  \t!<>,  .'i'.).") 

loi    ,  ibesit.%  ,    Us 

unit  ol,    IH,    171,   172 

Volt-amperage    of    voltaic    cell. 

Vibrator  for  mechanic  mas.-ace, 

Voltaic  cell,  S2 

si,  x:»,  xil 

oi  12 

acid  radicle  of,  S:i 

Volt-controller,  202 

\  ibrat,  ,r\-     cm  rent.     ."12.         See 

action  of,  x:;,  xl 

i',|uid,   1  x| 

also  Stulii-  inin   rurn  nl. 

local,  Ml 

Voltmeter,    170,   l!i:i,  21H 

\  illard's   in-trumenls   tor   mea.— 

amperage  of,  Xl,  So 

copj.er,  2111 

urini;  r-ra>  .    1  I'll 

arc-lamps  run  b\  ,  20.") 

d'Arsonvul's,  11)7 

inlerrupter      tor      alternating; 

bichromate,  HO  ' 

electrostatic,  217 

current-.  s:,i, 

Biuisen,  HI 

for  r-ray  work,  7XS 

lor  tnpha-e  current-,  Soil 

cadmium  standard,  1IU 

for  r-ray  work,  7XS,  Sol) 

osino-rejrulator        for        r-ray 

cliarninn     condciisi-r     from, 

in  -econdaiA    circuit   to  meas- 

lubes,   7H1 

2!  1 

ure  .r-ray   dosage,    1  l.",7 

t,  ,  rai.-e  \  aciium,   s:;r, 

chemic  action  in,  S2 

measuring   resistance  b\  ,   22H 

radio-clerometer      for      mea.— 

chlorid   silver  of,  112,  '.»:{ 

silver,  21H 

uriiij-'  penetration  of  .r-ray, 

Clark's  standard,  112 

static,    to    measure    dilTerence 

si:; 

component    parts  of,  XH 

in      potential     at      poles     ot 

\  ai\  c  or  ventril  tube,  7H7,  7l  IH 

condenser       in       shunt       to, 

tube,   Xlil 

,,-ci||oscope  connected  W  llll, 

chai'Kinfi  from,  24  1 

utilit\    of,  211) 

7,  Is 

Dan,  ill,  HI 

water,   2-11),  2.".0 

Vent  -il    tub,,    7s7 

l)e   l.a    Hue's,  H.'i 

VolM  >hm  r-ra\    tube,  7(11 

r-ra\      tube     with      accessory 

detail.-  of  various  kinds,  HI 

Vomit  inn,  h.vMt'oric,  -ls:i 

electrode,    7l,H 

discharging    condenser    b\  , 

N'ulva,    diseases    of,    electroU'sis 

\'illet'.-   laradixation    for   chloro- 

212 

for,    12(1 

ncope,    12H 

double-fluid,  HI 

endothelioma    of,    radium    in, 

Violet-rav    from    irla.-.-    vacuum 

economy  of,  H."> 

1272 

electrodes,  effects,  o72 

Kdi.-on-I.alande,  H2 

treatment,  V.1 

electro<les  of,  110 

Virtual  eli  ctrodes,  :;:',s 

elect  lolysis   by,   SS 

\\  A<;M:K     hammer     interrupter 

\  i-,  -oral  di-tuibaticcs,   neuralgia 

electrolytes      for,      precau- 

with faradic  current,   l.'ix.   lo'.i 

and,  .Mil 

tion.-  in  mi.xinir,  H.", 

\\aite      traiisfonner      for     r-ras 

Vitilit:o,    static    electricity    for, 

expenses  of,  H.'i 

work,  7.">0 

1  J7 

Klemmjj-'-  standard,  H2 

Walters'   radiometer,  Xt:{ 

\  ilreolls   eli  ctricitx  .    1!) 

for  cautery,  xt;,  xs 

\\  ajip'er    interrupter,    mterrup- 

Vocal  cord-,  pandysis  of,    17.', 

for  electroplating,  Xll 

tions  of,  x.",l 

radiouiaph\    of,   HHI1 

for  r-ray  work,  xii 

sinusoidal  apparatus,    Kill 

Volcker  and    l.icht,  nbery's  pye- 

gravity,'  HI 

tiaiisfonner    for    r-ra\-    work. 

phy,    mi,.; 

(  Irovi  •.  HI 

7.",(l 

Volt,    IH.    itl'.l,    172 

licat  production  by.  H7 

\\'ar      injuries,      physiotheratiy 

con,  roller    with    mercury    1  ur- 

regulation,  Xli,  S7 

and    elect  rodiajMio.-is    in, 

1  in,    m'.  rrupti  r,  7J7 

hi.-tory,  H7 

1.",  1 

eli     lor,       d,  ntal       tract  ional. 

hydroiren  liberation  in,  s.'j 

l{,,ntt:en-ra\    therapy  after, 

foi    eataphore-is,    In:, 

in  multiple,  si 

1  isli,    1  1HO 

Volta  contact   -eric-,  H7 

in  parallel,  XI 

wounds,     radiant      liyht      and 

e,    H7 

in  series,  si 

heat    for.  11X11 

induction-coil     fed     b.\     ar- 

\Varml h,  wa\  e  ol   nci;ati\  e  vari- 

(:  iTm'tiu,  distinction,    i:, 

rangement,   1  Is                              at  ion  and,  2so 

i'i,    S.  unit.   171.   172 

operated    b\  ,   .r-ra\    work 

Warts,  diatherm\    for,  (IISH 

,•  .   7- 

with,  717 

electrolysis  lor,    III) 

•     jnl 

r.alandc-Kdi.-on,  H2 

flat,    magnesium    eataphoresis 

1  .     n     of,    17 

I.e  Clanche,   HI 

for.    1011 

I'icto!  -  intluencinj/.  :,n,  :,1 

local  action  of,  Ml 

lunt'al  inn,     inacne-ium     cala- 

i-.  2  M  i    j:,  1 

magnetic  properties  of,  1  10 

pholesis   lor.    111(1 

r.-ipeiil         appli- 

maximum  el!icienc\  ,  sr,.  x,      ,          hi^h-l'iei|uenc\      currenl      lor, 

motor-   inn    b\  ,   2(1.",                                      i,2l 

,'!".v'!,  -,,- 

ope,:,u,lt.     eleetro!\lic     cell, 

radium   for,    IIH,    12I1H 

'  •  '    ''7  1 

part-  of,   XH 

'.;    ra\  'for,    1  1  s,    1  17s 

• 

polari/.ation   and,  SI,  ss 

Wasserman'n    reaction,   efTecl    ,,t 

n  ,  nl,   J  1  7 

pole-    of,     HO 

nil  ra\  lolei    ia;  -  on,  i,77 

inn  nt. 

U'alch,  irregular  il  \   ol,  in  power- 

,  ,  ", 

hoe-,  s,  2111.  :;oi'i 

•  •      imp-,  I'..',-, 

i,    i   lance  in    s,; 

Watei     coiiihicl  i\  u\    ot,   JJs 

•••     II;.;          '10!                :.     |.">2 

inductive,  'DM 

electrolysis   of,    2JX 

,  ,  t  .  ,                        i  :,  j 

miei  nal,  HH 

e\  apora'tion  of,  electric  chart',. 

•        tub, 

,,1,,,,     -j:i  | 

and     HI.", 

i,      Hi  i 

llowini-        Hinnmli        inclined 

o!      latic   i 

-hoii    ,  ircuilint'  of,  HO 

nibe,  inertia  of,  JI7 

; 

'-.  ,  i    chloiid,  112,  H:', 

radileron.-,    1  2HH 

lec 

||   ,id,   HO 

baths   in.    1  2HI1 

-Inee.   'Ill 

n     ,  .tance   of,   2JS 

le-i-t  H                                                                       im  di-  lance  of.  ss 

static      elect  (icily      compared 

,  ,nd  iid    cell-    t,,    measure 

tlieri'iioini  ler.    1 

vollameler,   2  I'.l,  2.',O 
\\  at,  i   cool,  ,1   r-ra.\    lube-,  7HI 
\\  atel     jacket       lube       loi        rectal 


\V:tll,    Si.   .S.'i,    172,   2OO 

\V'i'Stili)jhi)ilse-\erns1  lamp,  ii7."i 

Woo.l.  insulation  o|,  varni.-h  fot 

U  attinetef,    2OO 

Weston's     <-lectromat'iH'tic     gal- 

21 2 

Watts  ..f  dynamo,   calculating, 

vanometer,  SIH) 

point   electrode,    |:; 

12:5 

Wheatstcme  hridw,  20(1 

-plittmj;,       static       electrii  if. 

of  induction-coil,  i:._',  I  .-).'{ 

equivalent,  2:;o                                          from,  .".1 

\\a\e  current,  .">() 

for  testing   eonilnctivit  \-   of          Wood's    allo\,     h;-.iiiL^point     o> 

Morton,  li:j.     See  al.-o  SI'il- 

li.iuids,    IS.') 

21  1'.  1 

{<•   inii'<    nirri'iit. 

resistance    of    ^aU'anom- 

Work,  definition,    171 

stilt  ic,    li.'i.      Sec    also    S/ntir 

eter,  2:J2                                   Workroom,     ozone     production 

uiirr  nirn  nl. 

measuriim      resistance      liv,                tor,    11!) 

of  conti-action,  :«0 

2:!0                                              Wounds,     r>um-tiin-il.     infect.  -d 

of    low    potential,    L'7.").        See 

to    measure   internal    resist- 

with   fistula-,    copper   cuta- 

also    H'.in    of  ni't/ilticr    r-tri- 

ance  of  voltaic  cell,  '.Hi 

phoresis  for,    I0r, 

ntiiin. 

Wheel  interrupter,    I'.ll 

shifuish,  slat  ic  ele.-i  i  icit  \    fi,r, 

of  negative  variation,  27~> 

with    mercury  jet    and   illu- 

127 

alternating    relative    po- 

minating    nas     arc     sii]i- 

suppurating,      md\-anic      ftir- 

tential    of,    durum    ad- 

]>ression, ,s  .->.-) 

rent    for,  -121) 

vances  277 

t\i.c'    of    elect  r.,niamietic     in- 

war,  phvsiotherapv   and   elec- 

cold  and,  2SO 

terrupter,    1  1.'! 

trodiatrnosis    n,    l.".l.  .M2 

duration,  277 

Wideninn  of  dental   arch,   bene- 

radiant    lij-'ht    at  d   heat    for. 

fall  and  rise  of,  -'77 

fi.aal  elfect    of,   (Mil 

fiSli 

first,  current  durintr,  27d 

\\inisliurst    static    machine,    :;:', 

\\'ri.-t,  fluorosi-op-.   of,   Hlsr, 

forward   progress  of,   277 

\\'ind,     static     electrieit\-      from. 

fracture    of,     OilW,     lai«,,,i 

from    reflex    stimulation, 

.•Jl 

radioyraiiliy  of,    1001 

:M7 

Windint'     secondarv      coil,      117, 

radio|rrapli\'  of,    10!l() 

in   muscle,   ~~~>,   27X,   2sd 

l.-.O    l.->2 

radio^rapliy  of,    Ills') 

in  nerves,  27t>,  27.S 

,r-ra\-  coils,    1  .",  1  .    !.",_'                           '      Writer's     cram]),    traK'ani.'     r-tir- 

effect   of  narcotics,  I'M) 

WindowH  of  dark    room,  S70                      rent   for,  ;,]'.! 

fatijiue  and,   2.SO 

Wire,  2IS 

\\  r\    neck,  electricity  for,  old 

masking  of,  by  superpo- 

carr\ IIILT  capacity   of,  22^> 

sition,  27S 

coils   of,    heatinir    b\-    current, 

point  of  origin,  2S1 

222 

processes      takiim      place 

conduct  insr,    heat     ])roducl  ion 

X  \\-nil.l..\sMA,    diathc>rm\-    for, 

during.  L'Sl 
rate  of  progress  of,   2sl 

in,  221 
'empera'ure  of,   221 

f  '.'•>:  i 

Xanthin  calculi,  railioyraphx   oi. 

relative  potential  of,  277 

eoniliiction         throutrh        elei-- 

10.".7 

velocity,  2S1 

troiles  applied  laterally,  2s:, 

Xanthoma    multiplex,    hiirh-tte- 

warmth  and,  2SO 

copper.       See   (  'n/i/n  T   inr,  . 

(]uenc\    current    for,  Ii2:t 

Weber.    121) 

cross-sections  of,   I'l'.'l 

jr-ra\-  for,  Ii2d 

Weeks     and     Dixon's     modifica- 

for coil,   lenj_rtli    of.   dctermin- 

.V-ray.      See  Roiituin-rny. 

tion      of      Sweet's      locali/itiK 

inu',  220 

chart,  Dili 

number     of     turns,     deter- 

AVehnelt cathode,  7i:i 

mining,  221 

"\'ATKS  method  of  treatinc  deaf- 

interrupter, .",(1),  722,   ,  2:> 

natiL'es,  21s 

ness.  i:;.'i 

efficiency  of,    l:ili 

in  secondary  roil,   1  17 

'S'ellow   licht,  penetrating  jH.uer 

in    cutaneous    applications, 

in.-u  at  ion    of,    22:i.      See    also 

of,  Iid2 

:iso 

Inxnlntii.i,   <,f  ,rir,x. 

^'ohimbin      and      protoveratrin. 

interrupt  ions  of,  s.">.'j 

live,  accidents  from.  :',77 

studies   of,    in    nerve   stimula- 

parallel, rapid  radiotrraphv 

metal,   conduct  ;vit\    of,   1'  1  H 

tion,  :;  12 

with,  711 

resistance  of,   21'.i,  22(1 

variat  ions  in   current    with, 

rheostat,   2O1,    2O2 

727 

rubber-covered,    2Os 

.r-ra\  .wall  installation  with. 

~ize   of,    2IS 

/i  I.I:N^  .  current  >  lect  r>  i.-ei  ip>   i  if. 

7  in 

Win-N-sS    teletirapliN  ,     l.'iM,    .V.I, 

121o 

rectifier    for    alternating    cur- 

.')(') 7                                                              i     Xinc,  amal^an.ation  of,  for  vo  - 

rents,  72:> 

U'lrimr    for    installation    of    1  Ill- 

taic  cell.  s:i 

\  elitril    (lilies.    7sd 

volt      direct      current,     2<Hi, 

eataphofesi--  for  a  opecia,    10s 

U  eill's  ozone  apparatus,    1  t'.i 

207 

for   epithelioli.:,.     HI7 

treatment     of     pelvic     neiiral- 

inside,   207.   20s 

for  fi-tiila  in  aim,    107 

iria    in    neura-t  lienia,    .">2l 

outside,   207.   20s 

for     hemorrhage     ,  ndome- 

nt'  sciat  ii':i,  .V.l.'i 

toroinply  with  1  .  S.  Xation.il 

tritis,  40s 

\\  i  ;--'  formula   for  M  imulation, 

Hoard  of  I'ire  1    nderwritiT.*, 

for  ulcer  of  let',   ins 

.",ss 

regulations,  207    20:  i 

cotisutned    in   voltaic   cells,   d.") 

lau  of  excitability,  :{(."> 

\\  oltT's    electroscope.    L'O 

diaphraum,  7d  1 

Welding,  electric,   si; 

Wood,  acid-proving  of,  21:', 

elect  ri  il\  t  ic       UK  dient  ion       in 

\\  .  Isl.ach    licht    for   dark-room,               hacking  f<.r  plat.    .  sp.i 

Koiiiirrhi  a,   !07 

s7l)                                                                            hall  i-leetrnili  .    1 

Zirci>niun      oxide     in     stomacl 

\\  i   ;tilu;house  electrolytic  lurht- 

elect  rode,     hollow  .     Use    i  if,    ti'.l 

radiography,    1021 

tmm  arrester,  227 

iiisiilal  ion  of,  21  2.  21o 

Xo.,lak,    1022' 

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